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Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2018	Mar. 11, 2019	Jun. 29, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Gemphire Therapeutics Inc.
Entity Central Index Key	0001638287
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 128
Entity Common Stock, Shares Outstanding		14,265,411
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Entity Small Business	true
Entity Shell Company	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true

Condensed Balance Sheets - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 18,954,000	$ 18,473,000
Prepaid expenses	715,000	490,000
Deferred offering costs	0	21,000
Other assets	17,000	25,000
Total current assets	19,686,000	19,009,000
Deposits	8,000	8,000
Total assets	19,694,000	19,017,000
Current liabilities:
Accounts payable	2,044,000	4,025,000
Accrued liabilities	438,000	1,010,000
Term loan - current portion	9,437,000	1,355,000
Total current liabilities	11,919,000	6,390,000
Long-term liabilities:
Term loan		8,683,000
Other liabilities	1,000	3,000
Total liabilities	11,920,000	15,076,000
Commitments and contingencies (Note 5)
Stockholders’ equity:
Preferred stock, $0.001 par value; 10,000,000 shares authorized as of December 31, 2018 and 2017, no shares issued or outstanding as of December 31, 2018 and 2017.
Common stock, $0.001 par value; 100,000,000 shares authorized as of December 31, 2018 and 2017, 14,265,411 and 10,633,042 shares issued and outstanding at December 31, 2018 and 2017, respectively.	22,000	18,000
Additional paid in capital	91,863,000	64,397,000
Accumulated deficit	(84,111,000)	(60,474,000)
Total stockholders’ equity	7,774,000	3,941,000
Total liabilities and stockholders’ equity	$ 19,694,000	$ 19,017,000

Condensed Statements of Comprehensive Loss - USD ($)	3 Months Ended								12 Months Ended
Condensed Statements of Comprehensive Loss - USD ($)	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating expenses:
General and administrative	$ 1,468,000	$ 2,364,000	$ 2,574,000	$ 2,087,000	$ 1,487,000	$ 2,050,000	$ 4,678,000	$ 2,223,000	$ 8,493,000	$ 10,438,000	$ 5,956,000
Research and development	1,833,000	3,542,000	3,960,000	4,977,000	5,080,000	6,489,000	5,837,000	5,280,000	14,312,000	22,686,000	8,740,000
Total operating expenses	3,301,000	5,906,000	6,534,000	7,064,000	6,567,000	8,539,000	10,515,000	7,503,000	22,805,000	33,124,000	14,696,000
Loss from operations	(3,301,000)	(5,906,000)	(6,534,000)	(7,064,000)	(6,567,000)	(8,539,000)	(10,515,000)	(7,503,000)	(22,805,000)	(33,124,000)	(14,696,000)
Interest (expense) income	(178,000)	(172,000)	(144,000)	(160,000)	(179,000)	(132,000)	13,000	12,000	(654,000)	(286,000)	114,000
Other expense	(177,000)	(1,000)						(5,000)	(178,000)	(5,000)	(4,000)
Loss before income taxes	(3,656,000)	(6,079,000)	(6,678,000)	(7,224,000)	(6,746,000)	(8,671,000)	(10,502,000)	(7,496,000)	(23,637,000)	(33,415,000)	(14,586,000)
Provision (benefit) for income taxes									0
Net loss	(3,656,000)	(6,079,000)	(6,678,000)	(7,224,000)	(6,746,000)	(8,671,000)	(10,502,000)	(7,496,000)	(23,637,000)	(33,415,000)	(14,586,000)
Comprehensive loss	$ (3,656,000)	$ (6,079,000)	$ (6,678,000)	$ (7,224,000)	(6,746,000)	(8,671,000)	(10,502,000)	(7,496,000)	(23,637,000)	(33,415,000)	(14,586,000)
Adjustment to redemption value on Series A convertible preferred stock					$ (0.63)	$ (0.82)	$ (0.99)	$ (0.79)			(366,000)
Net loss attributable to common stockholders									$ (23,637,000)	$ (33,415,000)	$ (14,952,000)
Net loss per share:
Basic and diluted (Note 10)	$ (0.26)	$ (0.43)	$ (0.47)	$ (0.58)					$ (1.71)	$ (3.23)	$ (2.57)
Number of shares used in per share calculations:
Basic and diluted									13,805,552	10,349,136	5,809,396

Condensed Statements of Changes in Stockholders’ Equity (Deficit) - USD ($)	Common Stock Private placement	Common Stock	Additional Paid-in Capital Private placement	Additional Paid-in Capital	Accumulated Deficit	Private placement	Total
Balance at beginning of period at Dec. 31, 2015		$ 12,000			$ (12,392,000)		$ (12,380,000)
Balance at beginning of period (shares) at Dec. 31, 2015		3,758,488
Increase (Decrease) in Stockholders' Equity
Redemption value adjustment - Series A preferred stock				$ (285,000)	(81,000)		(366,000)
Conversion of Series A preferred stock to common stock		$ 1,000		8,318,000			8,319,000
Conversion of Series A preferred stock to common stock (in shares)		827,205
Separation of convertible note beneficial conversion feature upon contingency resolution				372,000			372,000
Conversion of convertible notes to common stock		$ 1,000		11,444,000			11,445,000
Conversion of convertible notes to common stock (in shares)		1,656,807
Issuance of common stock from offering		$ 3,000		30,275,000			30,278,000
Issuance of common stock from offering (in shares)		3,027,755
Issuance costs of offering				(4,168,000)			(4,168,000)
Share-based compensation - employee				1,498,000			1,498,000
Share-based compensation - non-employee				220,000			220,000
Net loss					(14,586,000)		(14,586,000)
Balance at end of period at Dec. 31, 2016		$ 17,000		47,674,000	(27,059,000)		20,632,000
Balance at end of period (shares) at Dec. 31, 2016		9,270,255
Increase (Decrease) in Stockholders' Equity
Issuance of common stock from offering	$ 1,000		$ 8,978,000			$ 8,979,000
Issuance of common stock from offering (in shares)	1,324,256
Issuance costs of offering			(1,287,000)			(1,287,000)
Exercise of stock options				41,000			41,000
Exercise of stock options (in shares)		23,531
Issuance of detachable stock warrants in connection with private placement			$ 3,562,000			$ 3,562,000
Exercise of warrants				156,000			$ 156,000
Exercise of warrants (in shares)		15,000					15,000
Share-based compensation - employee				5,244,000			$ 5,244,000
Share-based compensation - non-employee				29,000			29,000
Net loss					(33,415,000)		(33,415,000)
Balance at end of period at Dec. 31, 2017		$ 18,000		64,397,000	(60,474,000)		3,941,000
Balance at end of period (shares) at Dec. 31, 2017		10,633,042
Increase (Decrease) in Stockholders' Equity
Issuance of common stock from offering		$ 4,000		25,146,000			25,150,000
Issuance of common stock from offering (in shares)		3,592,858
Issuance costs of offering				(2,091,000)			(2,091,000)
Warrant issuance				196,000			196,000
Exercise of stock options				84,000			84,000
Exercise of stock options (in shares)		39,511
Exercise of warrants							0
Share-based compensation - employee				4,128,000			4,128,000
Share-based compensation - non-employee				3,000			3,000
Net loss					(23,637,000)		(23,637,000)
Balance at end of period at Dec. 31, 2018		$ 22,000		$ 91,863,000	$ (84,111,000)		$ 7,774,000
Balance at end of period (shares) at Dec. 31, 2018		14,265,411

Statements of Cash Flows - USD ($)	12 Months Ended
Statements of Cash Flows - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities
Net loss	$ (23,637,000)	$ (33,415,000)	$ (14,586,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation	4,131,000	5,273,000	1,718,000
Non-cash interest on convertible notes to related parties			145,000
Non-cash interest on convertible notes			256,000
Non-cash discount amortization on convertible notes to related parties			(17,000)
Non-cash discount amortization on term loan and convertible notes	346,000	137,000	(276,000)
Revaluation of premium conversion derivative			(850,000)
Non-cash interest upon conversion of convertible notes			649,000
Change in assets and liabilities:
Prepaid expenses and other assets	(196,000)	198,000	(55,000)
Accounts payable	(1,981,000)	2,007,000	1,477,000
Accrued and other liabilities	(574,000)	(1,101,000)	496,000
Net cash used in operating activities	(21,911,000)	(26,901,000)	(11,043,000)
Financing activities
Proceeds from issuance of term loan and convertible notes		10,000,000	2,651,000
Proceeds from issuance of convertible notes to related parties			2,500,000
Issuance costs related to term loan and convertible notes	(10,000)	(89,000)	(10,000)
Repayment of principal	(741,000)
Exercise of stock options	84,000	41,000
Exercise of warrants		156,000
Proceeds from sale of common stock and warrants	25,150,000	12,541,000	30,278,000
Offering costs	(2,091,000)	(1,287,000)	(3,963,000)
Deferred offering costs		(21,000)
Net cash provided by financing activities	22,392,000	21,341,000	31,456,000
Net increase (decrease) in cash and cash equivalents	481,000	(5,560,000)	20,413,000
Cash and cash equivalents at beginning of period	18,473,000	24,033,000	3,620,000
Cash and cash equivalents at end of period	18,954,000	18,473,000	24,033,000
Supplemental disclosure of cash flow information:
Cash paid for interest	488,000	291,000
Supplemental non-cash financing transactions:
Issuance of warrants in connection with term loan	$ 196,000
Redemption value change of Series A preferred stock			366,000
Bifurcation of premium conversion derivative related to convertible notes			505,000
Separation of convertible note beneficial conversion feature upon contingency resolution			372,000
Other Assets
Supplemental non-cash financing transactions:
Offering costs in other assets paid in prior year			205,000
Accounts Payable and Accrued Liabilities
Supplemental non-cash financing transactions:
Issuance costs in accounts payable and accrued liabilities		$ 10,000
Conversion of Convertible Notes
Supplemental non-cash financing transactions:
Issuance of warrants in connection with term loan			11,445,000
Conversion of Series A Preferred Stock
Supplemental non-cash financing transactions:
Conversion of Series A preferred stock to common stock			$ 8,319,000

The Company and Basis of Presentation	12 Months Ended
The Company and Basis of Presentation	Dec. 31, 2018
The Company and Basis of Presentation
The Company and Basis of Presentation	1. The Company and Basis of Presentation The Company, headquartered in Livonia, Michigan, is a clinical‑stage biopharmaceutical entity focused on developing and commercializing therapies for the treatment of dyslipidemias as well as NAFLD/NASH with an initial focus on orphan indications including HoFH, FCS, and FPL. The Company’s primary activities to date have been conducting research and development activities, planning and conducting clinical trials, performing business and financial planning, recruiting personnel and raising capital. The Company is subject to certain risks, which include the need to research, develop, and clinically test potentially therapeutic products, initially one product candidate gemcabene (also known as CI‑1027); obtain regulatory approval for its products and commercialize them around the world, if approved; expand its management scientific staff; finance its operations; and find collaboration partners to further advance development and commercial efforts. Initial Public Offering On August 4, 2016, the Company’s Registration Statement on Form S-1 (File No 333-210815) relating to its initial public offering (IPO) of its common stock was declared effective by the Securities and Exchange Commission (SEC). Pursuant to such Registration Statement, on August 10, 2016, the Company closed its IPO whereby 3,000,000 shares of its common stock were issued and sold at a public offering price of $10.00 per share. On September 8, 2016, the Company closed the sale of 27,755 shares of its common stock at the public offering price of $10.00 per share, representing a partial exercise of the underwriters’ over-allotment option, following which, the IPO terminated. The Company received net proceeds of approximately $26.1 million after deducting underwriting discounts and commissions of $2.1 million and other offering expenses of $2.1 million. Immediately prior to the IPO, the Company amended and restated its certificate of incorporation and bylaws to, among other things, change its authorized capital stock to consist of (i) 100,000,000 shares of common stock and (ii) 10,000,000 shares of undesignated preferred stock. Both the common stock and the preferred stock have a par value of $0.001 per share. Private Placement Offering On March 10, 2017, the Company entered into a securities purchase agreement for a private placement (the Private Placement) with a select group of accredited investors whereby, on March 15, 2017 the Company issued and sold 1,324,256 units at a price of $9.47 per unit for gross proceeds of approximately $12.5 million. Each unit consists of one share of the Company’s common stock and a warrant to purchase 0.75 shares of common stock. The warrants have an exercise price of $10.40 per share and are exercisable for a period of five years from the date of issuance. On April 20, 2017, the registration statement on Form S-1 (File No 333-217296) for the resale of the shares of common stock issued in the Private Placement and the shares of common stock to be issued upon exercise of the warrants issued in the Private Placement was declared effective by the SEC. Follow-On Public Offering On February 12, 2018, the Company completed an underwritten public offering (the Follow-On Offering) of 3,142,858 shares of common stock at the public offering price of $7.00 per share. As part of such offering, the Company issued 450,000 additional shares of common stock representing partial exercise of the underwriters’ overallotment option. The Company received net proceeds of approximately $23.1 million after deducting underwriting discounts and commissions and offering expenses. Reverse Stock Split In April 2016, the board of directors approved an amendment to the Company’s certificate of incorporation to effect a 1-for-3.119 reverse stock split (the Reverse Stock Split) for all common and Series A preferred stock. The Reverse Stock Split became effective on April 27, 2016 upon the filing of the amendment to the certificate of incorporation. The authorized shares and par value of the common stock and Series A preferred stock were not adjusted as a result of the Reverse Stock Split. All issued and outstanding common and Series A preferred stock, options for common stock and per share amounts contained in the financial statements were retroactively adjusted to reflect the Reverse Stock Split for all periods presented. Going Concern The accompanying financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The Company adopted Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-15, Presentation of Financial Statements - Going Concern (Subtopic 205-40) effective December 31, 2016, which requires the Company to make certain disclosures if it concludes that there is substantial doubt about the entity’s ability to continue as a going concern within one year from the date of the issuance of these financial statements. In the course of its activities, the Company has incurred losses and negative cash flows from operations since its inception. As of December 31, 2018, the Company had an accumulated deficit of $84.1 million. The Company expects to incur losses for the foreseeable future. The Company believes that its cash and cash equivalents of $19.0 million at December 31, 2018 are not sufficient to fund the Company's current operating plan for at least twelve months after the date the consolidated financial statements are issued. See “Contractual Obligations and Commitments—Term Loan” below regarding our prepayment of all outstanding indebtedness under the Term Loan subsequent to year end. We have no current source of revenue to sustain our present activities, and we do not expect to generate revenue until, and unless, the Food and Drug Administration (FDA) or other regulatory authorities approve gemcabene and we successfully commercialize gemcabene. Until such time, if ever, we expect to finance our cash needs through a combination of equity and debt financings as well as collaborations, strategic alliances and licensing arrangements. We do not have any committed external source of funds and there can be no assurance that the Company will be successful in acquiring additional funding at levels sufficient to fund its operations. These conditions raise substantial doubt about the Company’s ability to continue as a going concern. If the Company is unable to raise additional capital in sufficient amounts or on terms acceptable to it, the Company may have to significantly reduce its operations or delay, scale back or discontinue the development of gemcabene. The financial statements do not include any adjustments that might result from the outcome of this uncertainty.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2018

Summary of Significant Accounting Policies

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.

Cash and Cash Equivalents

The Company considers all highly liquid investments with an original maturity of 90 days or less at the time of deposit to be cash equivalents. The Company invests excess cash in readily available checking and savings accounts and highly liquid investments in money market accounts.

Fair Value of Financial Instruments

The Company’s financial instruments include principally cash and cash equivalents, other current assets, accounts payable, accrued liabilities and debt. The carrying amounts for these financial instruments reported in the balance sheets approximate their fair values. See Note 11 — Fair Value Measurements, for further discussion of fair value.

General and Administrative Expenses

General and administrative expenses consist primarily of personnel‑related costs, including salaries and share‑based compensation costs, for personnel in functions not directly associated with research and development activities. Other significant costs include legal fees related to intellectual property and corporate matters and professional fees for accounting and other services.

Research and Development Expenses

Research and development expenses consist of costs incurred in performing research and development activities, including compensation for research and development employees, costs associated with preclinical studies and trials, regulatory activities, manufacturing activities to support clinical activities, license fees, non‑legal patent costs, fees paid to external service providers that conduct certain research and development, clinical costs and an allocation of overhead expenses. Research and development costs are expensed as incurred.

Acquired In‑Process Research and Development Expenses

The Company includes costs to acquire or in‑license product candidates in acquired in‑process research and development expenses. The Company has acquired the right to develop and commercialize its product candidate gemcabene. These costs are immediately expensed provided that the payments do not also represent processes or activities that would constitute a “business” as defined under GAAP or provided that the product candidate has not achieved regulatory approval for marketing and absent obtaining such approval, has no alternative future use. Royalties owed on future sales of any licensed product will be expensed in the period the related revenues are recognized.

Income Taxes

The Company utilizes the liability method of accounting for income taxes as required by Accounting Standards Codification (ASC) 740, Income Taxes. Under this method, deferred tax assets and liabilities are determined based on differences between financial reporting and the tax basis of assets and liabilities and are measured using enacted tax rates and laws that will be in effect when the differences are expected to reverse. Currently, there is no provision for income taxes, as the Company has incurred operating losses to date, and a full valuation allowance has been provided on the net deferred tax assets.

Share‑Based Compensation

The Company accounts for share‑based compensation in accordance with the provisions of ASC 718, Compensation — Stock Compensation (ASC 718). Accordingly, compensation costs related to equity instruments granted are recognized at the grant‑date fair value. The Company records forfeitures when they occur. Share‑based compensation arrangements to non‑employees are accounted for in accordance with the applicable provisions of ASC 718 and ASC 505, Equity, using a fair value approach. The compensation costs of these arrangements are subject to re‑measurement as the equity instruments vest and are recognized as expense over the related service period (typically the vesting period of the awards).

Common Stock Valuation

Due to the absence of an active market for the Company’s common stock prior to the close of the IPO, the Company utilized methodologies in accordance with the framework of the American Institute of Certified Public Accountants’ Technical Practice Aid, Valuation of Privately‑Held Company Equity Securities Issued as Compensation, to estimate the fair value of its common stock. The valuation methodology included estimates and assumptions that required the Company’s judgment. These estimates and assumptions included a number of objective and subjective factors, including external market conditions affecting the biopharmaceutical industry sector, and the likelihood of achieving a liquidity event, such as an initial public offering or sale. Significant changes to the key assumptions used in the valuations could have resulted in different fair values of common stock at each valuation date.

Convertible Preferred Stock

On March 31, 2015, the Company issued 745,637 shares of Series A convertible preferred stock (the Series A preferred stock). On August 10, 2016, immediately prior to the closing of the IPO, the Company’s Series A preferred stock, together with accrued dividends thereon, converted into 827,205 shares of common stock. The Series A preferred stock prior to conversion was classified outside of permanent equity, in mezzanine equity, on the Company’s balance sheet. The Company initially records preferred stock that may be redeemed at the option of the holder, or based on the occurrence of events outside of the Company’s control, at the value of the proceeds received. Subsequently, if it is probable that the preferred stock will become redeemable, the Company recognizes changes in the redemption value immediately as they occur and adjusts the carrying amount of the instrument to equal the redemption value at the end of each reporting period. If it is not probable that the preferred stock will become redeemable, the Company does not adjust the carrying value. In the absence of retained earnings, these charges are recorded against additional paid‑in‑capital, if any, and then to accumulated deficit. As a result of their conversion to common stock on August 10, 2016 as described above, no shares of Series A preferred stock were outstanding as of December 31, 2018 and 2017.

Segment Information

Operating segments are components of an enterprise for which separate financial information is available and is evaluated regularly by the Company’s chief operating decision maker in deciding how to allocate resources and assessing performance. The Company’s chief operating decision maker is its Chief Executive Officer. The Company’s Chief Executive Officer views the Company’s operations and manages its business in one operating segment, which is the business of development and commercialization of therapeutics for the treatment of dyslipidemia, a serious medical condition that increases the risk of life threatening cardiovascular disease and NAFLD/NASH. Accordingly, the Company has a single reporting segment.

Jumpstart Our Business Startups Act Accounting Election

As an emerging growth company under the Jumpstart Our Business Startups Act (JOBS Act), the Company is eligible to take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies. The Company has irrevocably elected not to avail itself of this exemption and, therefore, will be subject to the same new or revised accounting standards as other public companies that are not emerging growth companies.

Recent Accounting Pronouncements

Recently Adopted Accounting Pronouncements

In May 2014, the FASB issued ASU 2014‑09, Revenue from Contracts with Customers (Topic 606), which supersedes the revenue recognition requirements in FASB ASC 605. The new guidance primarily states that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. In January 2017 and September 2017, the FASB issued several amendments to ASU 2014‑09, including updates stemming from SEC Accounting Staff Announcement in July 2017. The amendments and updates included clarification on accounting for principal versus agent considerations (i.e., reporting gross versus net), licenses of intellectual property and identification of performance obligations. These amendments and updates do not change the core principle of the standard but provide clarity and implementation guidance. The Company has adopted this standard on January 1, 2018 and selected the modified retrospective transition method. The Company modified its accounting policies to reflect the requirements of this standard; however, the planned adoption will not affect the Company’s financial statements and related disclosures for these periods or future periods until the Company generates revenues.

In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. The objective of this ASU is to eliminate the diversity in practice related to the classification of restricted cash or restricted cash equivalents in the statement of cash flows. For public business entities, this ASU is effective for annual and interim reporting periods beginning after December 15, 2017, with early adoption permitted. The amendments in this update should be applied retrospectively to all periods presented. The Company adopted this standard on January 1, 2018 and it did not have a material impact on the Company’s financial statements.

In May 2017, the FASB issued ASU 2017-09, Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting (ASU 2016-09), which provides guidance about which changes to the terms or conditions of a share-based payment awards require an entity to apply modification accounting in Topic 718. This pronouncement is effective for annual reporting periods beginning after December 15, 2017, with early adoption permitted. The Company has adopted this standard on January 1, 2018 and it did not have a material impact on the Company’s financial statements.

In March 2018, the FASB issued ASU 2018-05, Income Taxes (Topic 740), that codified the SEC Staff Accounting Bulletin 118 (SAB 118) issued on December 22, 2017, which provides guidance on accounting for the tax effects of the Tax Cuts and Jobs Act (the TCJA). SAB 118 provides a measurement period that should not extend beyond one year from the enactment date for companies to complete the accounting under ASC 740. In accordance with SAB 118, a company must reflect the income tax effects of those aspects of the TCJA for which the accounting under ASC 740 is complete. To the extent that a company’s accounting for certain income tax effects of the TCJA is incomplete, but for which they are able to determine a reasonable estimate, it must record a provisional amount in the financial statements. Provisional treatment is proper in light of anticipated additional guidance from various taxing authorities, the SEC, the FASB, and even the Joint Committee on Taxation. If a company cannot determine a provisional amount to be included in the financial statements, it should continue to apply ASC 740 on the basis of the provisions of the tax laws that were in effect immediately before the enactment of the TCJA. The Company has applied this guidance to its financial statements and it did not have an impact on the Company’s financial statements.

Recent Accounting Pronouncements Not Yet Adopted

In January 2016, the FASB issued ASU No. 2016‑01, Financial Instruments — Overall: Recognition and Measurement of Financial Assets and Financial Liabilities. The guidance affects the accounting for equity investments, financial liabilities under the fair value option and the presentation and disclosure requirements of financial instruments. The guidance is effective in the first quarter of fiscal 2019. Early adoption is permitted for the accounting guidance on financial liabilities under the fair value option. The Company is currently evaluating the impact of the new guidance on its financial statements.

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) and subsequently amended the guidance relating largely to transition considerations under the standard in January 2017 and July 2018. The objective of this update is to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. This ASU is effective for fiscal years beginning after December 15, 2018, including interim periods within those annual periods. The Company plans to adopt the standard on January 1, 2019, and will apply the modified retrospective approach to each lease in existence at the adoption date. As such, the Company would not restate comparative periods and would recognize any cumulative adjustment to retained earnings on the date of the adoption. The Company plans to elect the package of practical expedients provided under the standard. The Company is in the process of completing an impact analysis over the application of the standard as of the planned adoption date. The Company expects to recognize a range of approximately $0.1 million to $0.2 million of lease assets and liabilities on the balance sheet as of January 1, 2019. The new standard is not expected to have a material impact on the Company's statements of comprehensive loss or statements of cash flows. The finalization of our assessment may result in significant changes to our estimates.

In July 2017, the FASB issued ASU No. 2017-11, Earnings Per Share, Distinguishing Liabilities from Equity and Derivatives and Hedging, which changes the accounting and earnings per share for certain instruments with down round features. The amendments in this ASU should be applied using a cumulative-effect adjustment as of the beginning of the fiscal year or retrospective adjustment to each period presented and is effective for annual periods beginning after December 15, 2018, and interim periods within those periods. The Company is currently evaluating the requirements of this new guidance and has not yet determined its impact on the Company’s financial statements.

In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting (ASU 2018-07), which expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. An entity should generally apply the requirements of Topic 718 to nonemployee awards except in circumstances where there is specific guidance on inputs to an option pricing model and the attribution of cost. ASU 2018-07 specifies that Topic 718 applies to all share-based payment transactions in which a grantor acquires goods or services to be used or consumed in a grantor’s own operations by issuing share-based payment awards. The guidance also clarifies that Topic 718 does not apply to share-based payments used to effectively provide (1) financing to the issuer or (2) awards granted in conjunction with selling goods or services to customers as part of a contract accounted for under Topic 606. This guidance is effective for annual reporting periods beginning after December 15, 2018, with early adoption permitted, but no earlier than an entity’s adoption date of Topic 606. The Company is currently evaluating the impact of the new guidance on its financial statements.

In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement (ASU 2018-13). The new guidance modifies the disclosure requirements in Topic 820 as follows:

Removals: the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy; the policy for timing of transfers between levels; and the valuation processes for Level 3 fair value measurements.

Modifications: for investments in certain entities that calculate net asset value, an entity is required to disclose the timing of liquidation of an investee’s assets and the date when restrictions from redemption might lapse only if the investee has communicated the timing to the entity or announced the timing publicly; and the amendments clarify that the measurement uncertainty disclosure is to communicate information about the uncertainty in measurement as of the reporting date.

Additions: the changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period; and the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements.

This guidance is effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should all be applied prospectively for only the most recent interim or annual period presented in the initial year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. Early adoption is permitted. An entity is permitted to early adopt any removed or modified disclosures upon issuance of ASU 2018-13 and delay adoption of the additional disclosures until their effective date. The Company is currently evaluating the impact of the new guidance on its financial statements.

Debt

12 Months Ended

Dec. 31, 2018

Debt

Debt

4. Debt

Term Loan

On January 25, 2019, the Company agreed to prepay in full all outstanding indebtedness under the Loan and Security Agreement (the Original Loan Agreement) with Silicon Valley Bank (SVB) dated July 24, 2017 (the “Initial Effective Date”), as amended by the First Amendment, dated July 31, 2018 (the First Amendment and, the Original Loan Agreement, as amended by the First Amendment to Loan and Security Agreement, the Loan Agreement), which prepayment was effective January 28, 2019. Upon payoff, any unfunded commitments to make credit extensions or financial accommodations to the Company terminated, and all security interests and other liens granted to or held by SVB as security for the obligations were terminated and automatically released, except those that were specified as surviving termination (see Note 16 – Subsequent Events). This note describes the terms of the Loan Agreement in effect on December 31, 2018 prior to the prepayment.

The Loan Agreement established a term loan facility (the Term Loan) in the aggregate principal amount of up to $15,000,000 to be funded in up to three tranches. Of such amount, $10,000,000 was funded on the Initial Effective Date. A third tranche of $5,000,000 was available through November 30, 2018 conditioned on the occurrence of certain events and was not drawn by the Company. Under the Loan Agreement, if a Pre-Clinical Event did not occur on or prior to September 30, 2019 or, if at any time prior to a Pre-Clinical Event, the Company’s unrestricted cash balance at SVB was less than $18,000,000, the Company was required to either (i) provide cash security and maintain a cash balance in a restricted account at SVB in an amount not less than 100% of the amounts owed by the Company to SVB or (ii) prepay the Term Loan, including certain fees, in its entirety. All amounts advanced under the Term Loan would have matured on February 1, 2021.

In connection with the First Amendment, the Company issued a warrant to SVB (the Warrant) to purchase 36,000 shares of the Company’s common stock at an exercise price of $7.47 per share on July 31, 2018. The Warrant is immediately exercisable and has a term of ten years. The exercise price and number and type of shares underlying the Warrant are subject to adjustment upon specified events, including any stock dividends and splits, reverse stock split, recapitalization, reorganization or similar transaction, as described therein. The Warrant contains a “cashless exercise” feature that allows SVB to exercise the Warrant without a cash payment to the Company, on a net issuance basis, based upon the fair market value of the Company’s common stock at the time of exercise, upon the terms set forth therein. The Warrant was deemed to be a free-standing instrument and was accounted for as equity given that there were no variable terms. The Company recorded $0.2 million to additional paid-in capital upon issuance with an offset to a discount to the Term Loan. A Black-Scholes pricing model was used to estimate the aggregate fair value of the Warrant on the issuance date. Input assumptions used were as follows: risk-free interest rate of 2.96 percent; expected volatility of 66 percent; expected life of 10 years; and expected dividend yield of 0 percent. The discount to the Term Loan associated with the Warrant is being amortized as interest expense over the term of the Loan Agreement and amounted to $33,000 for the year ended December 31, 2018.

As of the date of payment on January 28, 2019, the Company had approximately $8.9 million in outstanding borrowings and approximately $1.0 million in outstanding interest and fees under the Loan Agreement, including the final payment fee equal to 10% of the original aggregate principal amount of the Term Loan funded by SVB and drawn by the Company, which were repaid in full at the time of payment. The obligations, liabilities, covenants, and terms that are expressly specified in the Loan Agreement and any other related loan and collateral security documents issued by the Company to SVB in connection with the transaction evidenced by the Loan Agreement as surviving termination shall continue to survive notwithstanding the payment, including without limitation, the Company’s indemnity obligations and the Company’s obligation to pay to SVB a success fee of 3.5% of the funded principal amount of the Term Loan in the event any of the following occur on or before 5:00 PM, Eastern time, on July 24, 2024: (a) the Company receives FDA approval for any new drug application for gemcabene, (b) a sale or other transfer of all or substantially all of the assets of the Company occurs, (c) a merger or consolidation of the Company with or into another person or entity occurs where the holders of the Company’s outstanding voting equity securities immediately prior to such merger or consolidation hold less than a majority of the issued and outstanding voting equity securities of the successor immediately following such transaction or (d) any sale by the holders of the Company’s outstanding voting equity securities where such holders do not continue to hold at least a majority of the Company’s issued and outstanding voting equity securities immediately following the consummation of such transaction. No event requiring payment of the success fee has occurred through the issuance date of these audited financial statements. Lastly, the Warrant to purchase 36,000 shares (subject to adjustment) of the Company’s common stock dated as of July 31, 2018 between the Company and SVB will remain outstanding and exercisable in accordance with its terms.

In connection with the First Amendment, the Company was charged $10,000 by SVB and the fee was recorded as a discount to the Term Loan; the discount is being amortized as interest expense over the term of the Loan Agreement and amounted to $2,000 for the year ended December 31, 2018. In addition, the Company incurred $20,000 in third-party legal fees which were recorded to general and administrative expense in the accompanying statements of comprehensive loss during the year ended December 31, 2018.

The Company was in compliance with the Loan Agreement covenants as of December 31, 2018 and through the repayment of the Term Loan on January 28, 2019.

Interest accrued on the unpaid principal balance at a floating per annum rate equal to the prime rate, except that, following an event of default, interest would have accrued at a rate up to 5% above the rate that is otherwise applicable. The prime rate in effect for the year ended December 31, 2018 ranged from 4.5% to 5.5% and the prime rate in effect for the year ended December 31, 2017 ranged from 4.25% to 4.5%. Lastly, debt issue costs that were incurred upon the July 2017 issuance of the Term Loan in the amount of $0.1 million were recorded as a discount to the Term Loan and were amortized ratably to interest expense over the term of the loan.

The Company recorded in aggregate $0.5 million and $0.3 million interest expense related to the Term Loan for the years ended December 31, 2018 and 2017, respectively.

As of December 31, 2018, minimum aggregate future payments under the Term Loan were as follows (in thousands) prior to repayment in January 2019:


	December 31,

2019	$	4,826
2020		4,579
2021		1,370
Total minimum payments		10,775
Amount representing interest and discounts		(1,338)
Present value of minimum payments		9,437
Current portion		(9,437)
Long-term portion	$	-

Future minimum interest payments under the Term Loan reflect the 5.5% per annum rate in effect at December 31, 2018 and on the date of repayment in January 2019. Given the intent of the Company to pay-off the Term Loan in January 2019 as of the December 31, 2018 balance sheet date, the Company classified the otherwise long-term portion of the Term Loan obligation as a current liability consistent with ASC 210 and other related accounting guidance. See Note 16 – Subsequent Events.

Interim Notes

On July 31, 2015, the Company entered into a convertible interim note financing (collectively with the notes issued in December 2015, February 2016 and April 2016, the Interim Notes), pursuant to which certain investors agreed to loan the Company approximately $2.8 million. On August 10, 2016, immediately prior to the closing of the IPO, the Company’s Interim Notes, together with accrued interest thereon, converted into 1,656,807 shares of common stock.

The Interim Notes accrued interest at a rate of 8% per annum, compounded annually, and would automatically convert into shares issued to investors in the Company’s next equity financing round that results in gross proceeds of at least $5.0 million (a Qualified Financing). The conversion would be equal to unpaid principal at 115% plus any unpaid accrued interest. The investors would be paid out principal at 200% if a change of control occurred before the next financing round. In the event that a Qualified Financing, change of control, or an IPO did not occur before July 31, 2016, the parties would then negotiate a price for conversion into a new round of stock.

In December 2015, the Company amended the Interim Notes and certain investors agreed to loan the Company an additional $2.7 million for a revised financing total of $5.5 million. The Interim Notes continued to accrue interest at an 8% rate per annum compounded annually, but were amended to automatically convert into shares of the same class of the Company’s next convertible preferred stock financing round (the Preferred Stock Financing). The conversion into shares issued in the Preferred Stock Financing would be equal to unpaid principal at 115% plus unpaid accrued interest. In the event that either a change of control occurs or the Company completes a public transaction which results in the Company’s stockholders holding securities listed on a national securities exchange, including an IPO, before the Preferred Stock Financing, the Interim Notes, as amended, would automatically convert into shares of the Company’s common stock at a conversion price of $6.70585 per share (which represents the original issue price of the Series A preferred stock) based on 100% of outstanding principal and unpaid accrued interest. Lastly, if a Preferred Stock Financing, change of control, or public transaction did not occur before December 31, 2016, the parties agreed to then negotiate a conversion price into a new round of stock.

In February 2016, certain investors agreed to loan the Company an additional $0.2 million for a revised financing total of $5.6 million. The Interim Notes continued to accrue interest at an 8% rate per annum compounded annually, but were amended to automatically convert into shares of the same class of the Company’s next Preferred Stock Financing. The conversion into shares issued in the Preferred Stock Financing would be equal to unpaid principal at 115% plus unpaid accrued interest. In the event that either a change of control occurs or the Company completes a public transaction which results in the Company’s stockholders holding securities listed on a national securities exchange, including an IPO, before the Preferred Stock Financing, the Interim Notes, as amended, would automatically convert into shares of the Company’s common stock at a conversion price of $6.70585 per share (which represents the original issue price of the Series A preferred stock as adjusted for the Reverse Stock Split) based on 100% of outstanding principal and unpaid accrued interest. Lastly, if a Preferred Stock Financing, change of control, or public transaction did not occur before December 31, 2016, the parties agreed to then negotiate a conversion price into a new round of stock.

In April 2016, the Company amended the Interim Notes and certain investors agreed to loan the Company an additional $5.0 million for a revised financing total, including Interim Notes previously issued, of $10.6 million. The Interim Notes continued to accrue interest at an 8% rate per annum compounded annually, but were amended so that 125% of the unpaid principal and accrued interest, would automatically convert into shares of the same class of the Company’s next convertible preferred stock financing round of at least $5.0 million (the Qualified Financing). In the event that either a change of control occurs or the Company completes a public transaction which results in the Company’s stockholders holding securities listed on a national securities exchange, including an IPO, before the Qualified Financing, 100% of outstanding principal and unpaid accrued interest on the Interim Notes, as amended, would automatically convert into shares of the Company’s common stock at a conversion price of $6.70585 per share, as adjusted for the Reverse Stock Split. Lastly, if a Qualified Financing, change of control, or public transaction did not occur, the Interim Notes would become payable on demand any time after December 31, 2016. The Company incurred issuance costs related to the April 2016 financing in the amount of $10,000. The Interim Notes were discounted for the issuance costs, and the discount was amortized to interest expense over their remaining term using the straight‑line method.

On August 10, 2016, immediately prior to the closing of the IPO, the Company’s Interim Notes, together with accrued interest thereon, converted into 1,656,807 shares of common stock. At the time of their issuance, the Interim Notes contained a conversion premium with regard to the conversion into shares at the time of the next Qualified Financing. The Company determined that the redemption feature under the Interim Notes qualified as an embedded derivative and was separated from its debt host. The bifurcation of the embedded derivative from its debt host resulted in a discount to the Interim Notes. The discount was amortized to interest expense over the term of the Interim Notes using the straight‑line method. The embedded derivative was accounted for separately on a fair market value basis. The Company recorded the fair value changes of the premium conversion derivative associated with the Interim Notes to interest income (expense) that amounted to $0.2 million for the year ended December 31, 2016. As a result of the conversion of the Interim Notes, together with accrued interest thereon, into common stock immediately prior to the closing of the IPO on August 10, 2016, there were no Interim Notes or premium conversion derivatives outstanding as of December 31, 2018, 2017 or 2016.

Convertible Series A Preferred Stock	12 Months Ended
Convertible Series A Preferred Stock	Dec. 31, 2018
Convertible Series A Preferred Stock
Convertible Series A Preferred Stock	7. Convertible Series A Preferred Stock On March 31, 2015, the Company issued 745,637 shares of Series A preferred stock at a per share price of $6.70585, as adjusted for the Reverse Stock Split, or $5.0 million in the aggregate, consisting of $1.5 million in cash and $3.5 million representing 125% of the principal and accrued and unpaid interest on previously issued convertible notes, all of which converted into shares of Series A preferred stock. On August 10, 2016, immediately prior to the closing of the IPO, the Company’s Series A preferred stock, together with accrued dividends thereon, converted into 827,205 shares of common stock. Prior to their conversion into shares of common stock, the Series A preferred stock had the following rights and preferences: Dividend Rights Dividends effectively accrued on a daily basis at a simple rate of 8% per annum on the sum of the original per share issue price. Dividends were effectively deemed declared daily and were payable upon the occurrence of certain events. In addition, the holders of the Series A preferred stock had rights to participate in common stock dividends, entitling holders of Series A preferred stock to a dividend payable at the same time as the dividend paid on common stock based on the number of shares of common stock each share of Series A preferred stock would convert into if such shares had converted on the record date. There were no dividends deemed payable and accrued as of December 31, 2018 or 2017 due to the conversion of the Series A preferred stock, together with accrued dividends thereon, on August 10, 2016 immediately prior to the closing of the IPO. Voting Rights Each share of Series A preferred stock was entitled to vote together with the common stock on all actions to be taken by the stockholders of the Company, based on the number of shares of common stock into which each share of Series A preferred stock could be converted. A separate vote of a majority of the outstanding shares of Series A preferred stock was required to (1) issue or authorize any class or series of equity securities or equivalents, (2) effect any transaction that results in a change in control, (3) change the principal business of the Company, enter new lines of business, or exit the current line of business, (4) issue of convertible debt above a certain threshold, or (5) materially sell, transfer, license, pledge or encumber technology or intellectual property. A management stock option plan approved by the board of directors, however, was not subject to a separate vote of the Series A preferred stockholders, but any subsequent increases to the authorized option pool were subject to approval by the Series A preferred stock holders via a separate vote. Liquidation Rights In the event of any liquidation, dissolution, or winding‑up of the Company, whether voluntary or involuntary, merger, consolidation or transaction in which over 50% of the Company’s voting power was transferred, or a sale, lease, transfer, exclusive license or disposition of all or substantially all of the assets of the Company, the Series A preferred stock holders were entitled to the assets of the Company legally available for distribution before any distribution or payment was made to the holders of common stock. The distribution amount would have been equal the original issue price of the Series A preferred stock (as adjusted for any stock dividends, combinations, splits or other recapitalizations since issuance), plus any accrued or declared but unpaid dividends thereon. After payment of the full liquidation preference to the Series A preferred stock holders, the remaining assets legally available for distribution would have been distributed to the holders of common stock and holders of the Series A preferred stock pro rata based on the number of shares of common stock each share of Series A preferred stock would convert into if such shares had converted immediately prior to such liquidation, dissolution, or winding‑up. Conversion Rights Shares of Series A preferred stock, at the option of the holder, could have been converted at any time into shares of common stock. The conversion rate would have been obtained by dividing the Series A preferred stock original issue price of $6.70585 per share, as adjusted for the Reverse Stock Split, by the conversion price per share in effect at the time of conversion. The Series A conversion price was initially equal to the original issue price, but could be adjusted on a broad‑based weighted average basis in connection with certain dilutive events. The Series A holder was also entitled to receive additional shares of common stock for any unpaid Series A dividends (whether or not declared). Shares of Series A preferred stock would have automatically converted into common stock based upon the then‑effective Series A conversion price upon the affirmative vote or consent of the holders of at least a majority of the outstanding shares of the Series A preferred stock, or at the closing of a firmly underwritten public offering. The conversion price for the Series A preferred stock was $6.70585 per share (as adjusted for the Reverse Stock Split) at the time of the conversion of the Series A preferred stock, together with accrued dividends thereon, immediately prior to the closing of the IPO on August 10, 2016. Redemption Rights The holders of at least 80% of the outstanding shares of Series A preferred stock could have required the Company to redeem all outstanding shares of Series A preferred stock at any time on or after December 31, 2020 at a redemption price equal to the greater of 150% of the liquidation preference of the Series A preferred stock or the fair market value per share plus any unpaid declared dividends. The liquidation preference of the Series A preferred stock was defined as an amount per share equal to $6.70585, as adjusted from time to time for any stock dividends, combinations, splits or recapitalizations, plus any accrued or declared but unpaid dividends thereon. The redemption value for redeemable preferred stock could have at times been based on fair market value. The assumptions used in calculating the estimated fair market value at each reporting period represented the Company’s best estimate, however, inherent uncertainties were involved. As a result, if factors or assumptions changed, the estimated fair value could have been materially different. The Company recognized changes in the redemption value immediately as they occurred and adjusted the carrying amount of the instrument to equal the redemption value at the end of each reporting period since it was probable that the instruments would have become redeemable. In the absence of retained earnings, these charges were recorded against additional paid‑in‑capital, if any, and then to accumulated deficit. The Company evaluated the Series A preferred stock and determined that it was considered an equity host under ASC 815, Derivatives and Hedging. In making this determination, the Company’s analysis followed the whole instrument approach that compared an individual feature against the entire Series A preferred stock instrument that included that feature. The Company’s analysis was based on a consideration of the economic characteristics and risks of the Series A preferred stock. More specifically, the Company evaluated all of the stated and implied substantive terms and features of the Series A preferred stock, including: (1) redemption features and their underlying exercisability, (2) existence of any protective covenants, (3) nature of dividends rights, (4) nature of voting rights, and (5) the existence and nature of any conversion rights. As a result of the above, the Company concluded that the Series A preferred stock represented an equity host, and as such, the redemption and/or conversion features of the Series A preferred stock were considered to be clearly and closely related to the associated Series A preferred stock host instrument. Accordingly, the redemption and/or conversion features of the Series A preferred stock were not considered an embedded derivative that required bifurcation.

Share-Based Compensation

12 Months Ended

Dec. 31, 2018

Share-Based Compensation

Share-Based Compensation

9. Share‑Based Compensation

Share-based compensation expense was included in general and administrative and research and development costs as follows in the accompanying statements of comprehensive loss (in thousands):


	Year Ended
	December 31,
	2018		2017		2016
General and administrative	$	2,378	$	4,091	$	1,166
Research and development		1,753		1,182		552
Total share-based compensation	$	4,131	$	5,273	$	1,718

Restricted Stock Awards

During the years ended December 31, 2018, 2017 and 2016, the Company did not grant any restricted stock awards (RSAs). Previously granted RSAs were subject to various vesting schedules and generally vested ratably over a six to twenty four month period coinciding with their respective service periods. During the years ended December 31, 2018, 2017 and 2016, no RSAs were forfeited.

A summary of RSA grant activity is as follows:


	Number of	Weighted-Average
	Shares	Fair Value (per share)

Non‑vested at December 31, 2015	348,093	$	0.09
Granted	—	$	—
Vested	(344,084)	$	0.09
Non‑vested at December 31, 2016	4,009	$	0.21
Granted	—	$	—
Vested	(4,009)	$	0.21
Non‑vested at December 31, 2017	—	$	—
Granted	—	$	—
Vested	—	$	—
Non‑vested at December 31, 2018	—	$	—

Grant date fair market value for the RSAs issued prior to the IPO was based on traditional valuation techniques and methods in determining the fair value of the Company’s equity as a private company including market, income, and cost valuation approaches. A number of objective and subjective factors were considered including contemporaneous and retrospective valuations of its common stock performed by an unrelated valuation specialist, sales of the Company’s convertible preferred stock to unrelated third parties, valuations of comparable peer public companies, the lack of liquidity of the Company’s capital stock and general and industry‑specific economic outlook. The fair value of the Company’s common stock was determined by the Company’s board of directors prior to the IPO.

Stock Options

In April 2015, the Company adopted a 2015 Equity Incentive Plan (the 2015 Plan) under which 320,615 shares of the Company’s common stock were reserved for issuance to employees, directors and consultants. The 2015 Plan permits the grant of incentive and non‑statutory stock options, appreciation rights, restricted stock, restricted stock units, performance stock and cash awards, and other stock‑based awards.

Amendment and Restatement of 2015 Equity Incentive Plan

In April 2016 the Company’s board of directors approved the Company’s amended and restated 2015 Plan (the A&R 2015 Plan). The A&R 2015 Plan became effective immediately upon the execution and delivery of the underwriting agreement related to the IPO. The A&R 2015 Plan provides for the grant of stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance-based stock awards and other forms of equity awards, as well as performance cash awards. The Company initially reserved 2,400,000 shares of common stock for issuance under the A&R 2015 Plan.

During the years ended December 31, 2018, 2017 and 2016, the Company granted an aggregate of 772,000, 150,500 and 1,825,700, respectively, of stock options under the A&R 2015 Plan or the 2015 Plan to its officers, directors, employees and consultants, generally vesting over a three or four-year period.

Inducement Plan

In September 2016 the Company’s board of directors approved the Company’s Inducement Plan (the Inducement Plan). The Company initially reserved 300,000 shares of its common stock to be used exclusively for grants of awards to individuals who were not previously employees or directors of the Company, as an inducement material to the individual’s entry into employment with the Company within the meaning of Rule 5635(c)(4) of the Nasdaq Listing Rules. The Plan was approved by the Company’s board of directors without stockholder approval pursuant to Rule 5635(c)(4), and the terms and conditions of the Plan are substantially similar to the Company’s stockholder-approved A&R 2015 Plan. During the years ended December 31, 2018, 2017 and 2016 was 50,000, 98,000 and 198,000 stock options to newly-hired officers and employees were granted, respectively, under the Inducement Plan, generally vesting over a four-year period.

The following table summarizes the Company’s stock option plan activity for the years ended December 31, 2018, 2017 and 2016 as follows:


				Weighted‑
		Weighted		Average
		Average		Remaining	Aggregate
	Number of	Exercise		Contractual	Intrinsic
	Options	Price		Term (years)	Value(1)

Outstanding at December 31, 2015	302,842	$	2.43	9.60	$	1,031,000
Granted	2,023,700	$	10.07	—		—
Exercised	—	$	—	—		—
Forfeited/Cancelled	(83,742)	$	9.12	—		—
Outstanding at December 31, 2016	2,242,800	$	9.07	9.48	$	(2,759,000)
Granted	248,500	$	12.24	—		—
Exercised	(23,910)	$	1.92	—		—
Forfeited/Cancelled	(3,250)	$	1.34	—		—
Outstanding at December 31, 2017	2,464,140	$	9.46	8.58	$	(3,715,000)
Granted	822,000	$	8.24	—		—
Exercised	(40,398)	$	2.25	—		—
Forfeited/Cancelled	(444,968)	$	10.61	—		—
Outstanding at December 31, 2018	2,800,774	$	9.02	7.96	$	(22,994,287)
Vested and exercisable at December 31, 2018	1,812,181	$	9.15	7.72	$	(15,120,294)
Vested and expected to vest at December 31, 2018	2,800,774	$	9.02	7.96	$	(22,994,287)

⁽¹⁾

The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of our common stock as of December 31, 2018, 2017 and 2016 of $0.81, $7.95 and $7.84 per share, respectively.

The weighted average fair value per share of options granted during the years ended December 31, 2018, 2017 and 2016 was $5.07, $7.35 and $6.37, respectively.

The Company measures the fair value of stock options with service‑based and performance‑based vesting criteria to employees, consultants and directors on the date of grant using the Black‑Scholes option pricing model. The fair value of equity instruments issued to non‑employees is re‑measured as the award vests. The Company does not have history to support a calculation of volatility and expected term. As such, the Company has used a weighted‑average volatility considering the volatilities of several guideline companies.

For purposes of identifying similar entities, the Company considered characteristics such as industry, length of trading history, and stage of life cycle. The assumed dividend yield was based on the Company’s expectation of not paying dividends in the foreseeable future. The average expected life of the options was determined based on the mid‑point between the vesting date and the end of the contractual term according to the “simplified method” as described in Staff Accounting Bulletin 110. The risk‑free interest rate is determined by reference to implied yields available from U.S. Treasury securities with a remaining term equal to the expected life assumed at the date of grant. The Company records forfeitures when they occur.

The weighted‑average assumptions used in the Black‑Scholes option‑pricing model are as follows:


	Year Ended
	December 31,
	2018			2017			2016

Expected stock price volatility		66.3	%		65.8	%		71.447	%
Expected life of options (years)		5.8			5.9			6.02
Expected dividend yield		0	%		0	%		0	%
Risk free interest rate		2.7	%		2.0	%		1.2	%

During the years ended December 31, 2018, 2017 and 2016, 709,521, 861,645 and 276,248 stock options vested, respectively. The weighted average fair value per share of options vesting during the years ended December 31, 2018, 2017 and 2016 was $6.15, $5.99 and $4.59, respectively. During the years ended December 31, 2018, 2017 and 2016, 444,968, 3,250, and 83,742 stock options were forfeited, respectively. As of December 31, 2018, 701,261 shares were available for future issuance under the A&R 2015 and Inducement Plans.

Under the A&R 2015 Plan, common shares reserved automatically increase on January 1st of each year, for a period of 10 years commencing on January 1, 2017 and ending on (and including) January 1, 2026, to an amount equal to 20% of the Company’s fully-diluted shares as of December 31st of the preceding calendar year. Notwithstanding the foregoing, the Company’s board of directors may act prior to January 1st of a given year to provide that there will be no January 1st increase in the shares reserved for such year, or that the increase in shares reserved for such year will be a lesser number of shares than what would have otherwise been allowed to occur under the provision. Effective January 1, 2018, 415,077 shares were added to the A&R 2015 Plan under the share reserve provision. There were no shares added to the A&R 2015 Plan under the share reserve provision during fiscal year 2017 or 2016. Effective January 1, 2019, 501,001 shares were added to the A&R 2015 Plan under the share reserve provision. See Note 16 – Subsequent Events.

Unrecognized share‑based compensation cost for the RSAs and stock options issued under the Company’s 2014 Shareholders Agreement, A&R 2015 Plan and Inducement Plan was $3.9 million as of December 31, 2018. All of the unrecognized compensation cost was related to the stock options. The non‑employee portion of the unrecognized compensation cost was estimated utilizing the Company’s fair market value for its common stock as of December 31, 2018. The unrecognized share‑based expense is expected to be recognized over a weighted average period of 1.5 years.

Adoption of 2016 Employee Stock Purchase Plan

In April 2016 the Company’s board of directors approved the 2016 Employee Stock Purchase Plan (the ESPP) in order to enable eligible employees to purchase shares of the Company’s common stock at a discount following the effective date of the IPO. The Company’s stockholders also approved the ESPP in April 2016 and the ESPP became effective immediately upon the execution and delivery of the underwriting agreement related to the IPO. The Company initially reserved 150,000 shares of common stock for issuance under the ESPP. As of December 31, 2018, no shares were purchased under the ESPP.

Net Loss Per Common Share

12 Months Ended

Dec. 31, 2018

Net Loss Per Common Share

Net Loss Per Common Share

10. Net Loss Per Common Share

Basic earnings or loss per share of common stock is computed by dividing net loss by the weighted average number of shares of common stock outstanding during the period. The holders of the Series A preferred stock had rights to participate in common stock dividends, entitling the holders of Series A preferred stock to a dividend payable at the same time and rate per share as the dividend paid on common stock based the number of shares of common stock each share of Series A preferred stock would have converted into if such shares had converted on the record date. The Series A preferred stock, however, did not have a contractual obligation to share in the losses of the Company, and as such, no losses were allocated to the Series A preferred stock for the purposes of the basic loss per share calculation while they were outstanding.

Diluted earnings or loss per share of common stock is computed similarly to basic earnings or loss per share except the weighted average shares outstanding are increased to include additional shares from the assumed exercise of any common stock equivalents, if dilutive. The Company’s RSAs, stock options, warrants, shares of Series A preferred stock, and convertible notes are considered common stock equivalents while outstanding for this purpose. Diluted earnings is computed utilizing the treasury stock method for the RSAs, stock options and warrants, and in the case of the Series A preferred stock, either the two‑class method or the if‑converted method, whichever was more dilutive. No incremental common stock equivalents were included in calculating diluted loss per share because such inclusion would be anti‑dilutive given the net loss reported for the years ended December 31, 2018, 2017 and 2016. The following table sets forth the computation of basic and diluted loss per share as of December 31, 2018, 2017 and 2016 (in thousands, except share and per share amounts):


	Year Ended
	2018		2017		2016
Numerator:
Net loss	$	(23,637)	$	(33,415)	$	(14,586)
Adjustment to redemption value on Series A convertible preferred stock		—		—		(366)
Net loss attributed to common stock holders	$	(23,637)	$	(33,415)	$	(14,952)
Denominator:
Basic and diluted weighted average common shares outstanding		13,805,552		10,349,136		5,809,396
Basic and diluted net loss per share	$	(1.71)	$	(3.23)	$	(2.57)

The following potential common shares were not considered in the computation of diluted net loss per share as their effect would have been anti‑dilutive:


	Year Ended
	2018	2017	2016
Stock options	2,800,774	2,464,140	2,242,800
Restricted stock awards	—	—	4,009
Warrants	1,014,204	978,204	—
Series A	—	—	—
Convertible notes	—	—	—

Fair Value Measurements

12 Months Ended

Dec. 31, 2018

Fair Value Measurements

Fair Value Measurements

11. Fair Value Measurements

The Company follows accounting guidance that emphasizes that fair value is a market‑based measurement, not an entity specific measurement. Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” Fair value measurements are defined on a three level hierarchy:

Level 1 inputs: Unadjusted quoted prices for identical assets or liabilities in active markets;

Level 2 inputs: Quoted prices for similar assets and liabilities in active markets, quoted prices in markets that are not active, or inputs which are observable, weather directly or indirectly, for substantially the full term of the asset or liability;

Level 3 inputs: Unobservable inputs that reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability in which there is little, if any, market activity for the asset or liability at the measurement date.

As of December 31, 2018 and 2017, the fair values of cash and cash equivalents, prepaids, other assets, accounts payable and accrued liabilities approximated their carrying values because of the short‑term nature of these assets or liabilities. The estimated fair value of the Company’s Interim Notes prior to conversion upon the close of the IPO, and Term Loan was based on amortized cost which was deemed to approximate fair value. The derivative liability associated with the conversion premium on the Interim Notes while outstanding was based on cash flow models discounted at current implied market rates evidenced in recent arms‑length transactions representing expected returns by market participants for similar instruments which were based on Level 3 inputs.

The following table provides a roll‑forward of the Company’s premium conversion derivative liabilities measured at fair value on a recurring basis using unobservable level 3 inputs (in thousands):


	For the Year Ended December 31,
	2018		2017		2016
Balance as of beginning of period	$	—	$	—	$	345
Issuance of underlying convertible notes		—		—		505
Change in fair value of premium conversion derivative		—		—		(850)
Reversal of premium conversion derivative associated with note extinguishment		—		—		—
Redemption of underlying convertible notes		—		—		—
Balance as of end of period	$	—	$	—	$	—

There were no financial instruments measured on a recurring basis as of December 31, 2018 and 2017 and on a non‑recurring basis for any of the periods presented.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Income Taxes

12 Months Ended

Dec. 31, 2018

Income Taxes

Income Taxes

12. Income Taxes

On December 22, 2017, the Tax Cuts and Jobs Act (the TCJA), which significantly modified U.S. corporate income tax law, was signed into law by President Trump. The TCJA contains significant changes to corporate income taxation, including but not limited to the reduction of the corporate income tax rate from a top marginal rate of 35% to a flat rate of 21%, limitation of the tax deduction for interest expense to 30% of earnings (except for certain small businesses), limitation of the deduction for net operating losses to 80% of current year taxable income and generally eliminating net operating loss carrybacks, allowing net operating losses to carryforward without expiration, one-time taxation of offshore earnings at reduced rates regardless of whether they are repatriated, elimination of U.S. tax on foreign earnings (subject to certain important exceptions), immediate deductions for certain new investments instead of deductions for depreciation expense over time, and modifying or repealing many business deductions and credits (including changes to the orphan drug tax credit and changes to the deductibility of research and experimental expenditures that will be effective in the future). This revaluation resulted in a reduction to the Company’s deferred tax asset of $6.8 million as of December 31, 2017. This amount was offset by a corresponding reduction to the Company’s valuation allowance. The other provisions of the TCJA did not have a material impact on the December 31, 2017 financial statements. The Company’s final determination of the TCJA impact and the remeasurement of its deferred assets and liabilities was completed prior to the deadline of one year from the enactment of the TCJA. For the year ended December 31, 2018, there were no material changes to the analysis originally performed as of December 31, 2017.

The effective tax rate for the years ended December 31, 2018, 2017 and 2016 was zero percent. A reconciliation of income tax computed at the statutory federal income tax rate to the provision (benefit) for income taxes included in the accompanying statements of comprehensive loss is as follows:


	For the Year Ended December 31,
	2018		2017		2016
Income tax (benefit) provision at federal statutory rate	(21.0)	%	(34.0)	%	(34.0)	%
Valuation allowance	28.2		21.0		40.2
U.S. tax reform	-		20.2		—
State income tax, net of federal benefit	(4.8)		(4.1)		(4.7)
Convertible notes	—		—		1.1
Research credits	(3.0)		(3.6)		(4.0)
Other	0.6		0.5		1.4
Effective tax rate	—	%	—	%	—	%

Significant components of the Company’s deferred tax assets and liabilities are summarized in the tables below as of (in thousands):


	Year Ended December 31,
Deferred tax assets:	2018		2017
Federal and state operating loss carryforwards	$	5,073	$	3,349
Research and development costs deferral election		12,264		8,881
Acquired intangibles		235		235
Term loan		—		33
Charitable contributions		21		14
Stock-based compensation		2,618		1,722
Research and development credit carryforwards		2,655		1,947
		22,866		16,181
Valuation allowance		(22,866)		(16,181)
Total deferred tax assets, net of valuation allowance		—		—
Deferred tax liabilities:
Total deferred tax liabilities		—		—
Net deferred tax assets	$	—	$	—

As of December 31, 2018 and 2017, the Company had gross deferred tax assets of approximately $22.9 million and $16.2 million, respectively. Realization of the deferred assets is primarily dependent upon future taxable income, if any, the amount and timing of which are uncertain. The Company has had significant pre‑tax losses since its inception. The Company has not yet generated revenues and faces significant challenges to becoming profitable. Accordingly, the net deferred tax assets have been fully offset by a valuation allowance of $22.9 million and $16.2 million as of December 31, 2018 and 2017, respectively. U.S. net deferred tax assets will continue to require a valuation allowance until the Company can demonstrate their realizability through sustained profitability or another source of income.

As of December 31, 2018 and 2017, the tax effect of the Company’s federal net operating loss carryforwards was approximately $4.2 million and $2.8 million, respectively. The Company had federal research credit carryforwards as of December 31, 2018 and 2017 of approximately $2.6 million and $1.9 million, respectively. The federal net operating loss incurred prior to January 1, 2018 and tax credit carryforwards will begin to expire in 2034 if not utilized. Federal net operating losses incurred after December 31, 2017 will not expire. As of December 31, 2018 and 2017, the Company had state net operating loss carryforwards with a tax effect of approximately $0.9 million and $0.6 million, respectively. The Company had state research credit carryforwards of $0.1 million and $45,000 as of December 31, 2018 and 2017, respectively. The state net operating loss carryforwards will begin to expire in 2026, if not utilized, and the state research credit carryforwards will begin to expire in 2023 if not utilized. Recent tax reform legislation has significantly revised the rules applicable to the utilization of net operating losses for tax years either beginning or ending after January 1, 2018.

Utilization of the net operating loss carryforwards and credits may be subject to a substantial annual limitation due to the ownership change limitations provided by Section 382 of the Internal Revenue Code of 1986, as amended, and similar state provisions. Generally, in addition to certain entity reorganizations, the limitation applies when one or more “5-percent shareholders” increase their ownership, in the aggregate, by more than 50 percentage points over a 36‑month time period testing period, or beginning the day after the most recent ownership change, if shorter. The annual limitation may result in the expiration of net operating losses and credits before utilization.

The Company recognizes interest and/or penalties related to uncertain tax positions in income tax expense. There were no uncertain tax positions as of December 31, 2018 and 2017, and as such, no interest or penalties were recorded to income tax expense.

The Company’s corporate returns are subject to examination beginning with the 2015 tax year for federal and in various state jurisdictions.

Quarterly Data

12 Months Ended

Dec. 31, 2018

Supplementary Data — Quarterly Financial Data (unaudited)

Supplementary Data — Quarterly Financial Data (unaudited)

13. Supplementary Data — Quarterly Financial Data (unaudited)

The following table presents certain unaudited quarterly financial information for each of the eight fiscal quarters in the period ended December 31, 2018. This quarterly information has been prepared on the same basis as the audited financial statements and includes all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation of the information for the periods presented. The results for these quarterly periods are not necessarily indicative of the operating results for a full year or any future period.


	Three Months Ended
	December 31,		September 30,		June 30,		March 31,
	2018 (B)		2018 (B)		2018		2018
	(in thousands, except per share amounts)
Operating expenses:
General and administrative	$	1,468	$	2,364	$	2,574	$	2,087
Research and development		1,833		3,542		3,960		4,977
Total operating expenses		3,301		5,906		6,534		7,064
Loss from operations		(3,301)		(5,906)		(6,534)		(7,064)
Interest expense		(178)		(172)		(144)		(160)
Other expense		(177)		(1)		—		—
Loss before income taxes		(3,656)		(6,079)		(6,678)		(7,224)
Provision (benefit) for income taxes		—		—		—		—
Net loss		(3,656)		(6,079)		(6,678)		(7,224)
Other comprehensive loss, net of tax		—		—		—		—
Comprehensive loss	$	(3,656)	$	(6,079)	$	(6,678)	$	(7,224)
Net loss per share:
Basic and diluted (A)	$	(0.26)	$	(0.43)	$	(0.47)	$	(0.58)

	Three Months Ended
	December 31,		September 30,		June 30,		March 31,
	2017		2017		2017		2017
	(in thousands, except per share amounts)
Operating expenses:
General and administrative	$	1,487	$	2,050	$	4,678	$	2,223
Research and development		5,080		6,489		5,837		5,280
Total operating expenses		6,567		8,539		10,515		7,503
Loss from operations		(6,567)		(8,539)		(10,515)		(7,503)
Interest (expense) income		(179)		(132)		13		12
Other expense		—		—		—		(5)
Loss before income taxes		(6,746)		(8,671)		(10,502)		(7,496)
Provision (benefit) for income taxes		—		—		—		—
Net loss		(6,746)		(8,671)		(10,502)		(7,496)
Other comprehensive loss, net of tax		—		—		—		—
Comprehensive loss	$	(6,746)	$	(8,671)	$	(10,502)	$	(7,496)
Net loss per share:
Basic and diluted (A)	$	(0.63)	$	(0.82)	$	(0.99)	$	(0.79)

^(A)

Net loss per share for the year may not equal the sum of the four historical quarters loss per share due to changes in weighted-average shares outstanding.

^(B)

On September 18, 2018, the Company’s Board of Directors approved a workforce reduction involving 5 employees (or 33% of the workforce at that time) to lower costs and conserve cash resources in light of the previously announced request by the FDA for additional pre-clinical data required in order to schedule an End of Phase 2 (EOP2) meeting for gemcabene in the Company’s target indications. Related expenses recognized during the year ended December 31, 2018 totaled approximately $1.6 million, largely in the third quarter, of which approximately $0.6 million was recorded as general and administrative expense and $1.0 million was recorded as research and development expense.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2018

Summary of Significant Accounting Policies

Use of Estimates

Cash and Cash Equivalents

Fair Value of Financial Instruments

General and Administrative Expenses

Research and Development Expenses

Acquired In-Process Research and Development Expenses

Acquired In‑Process Research and Development Expenses

Income Taxes

Share-Based Compensation

Share‑Based Compensation

Common Stock Valuation

Convertible Preferred Stock

Segment Information

Jumpstart Our Business Startups Act Accounting Election

Recent Accounting Pronouncements

Recently Adopted Accounting Pronouncements

Recent Accounting Pronouncements Not Yet Adopted

Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

Share-Based Compensation

Schedule of share-based compensation expense

Share-based compensation expense was included in general and administrative and research and development costs as follows in the accompanying statements of comprehensive loss (in thousands):


	Year Ended
	December 31,
	2018		2017		2016
General and administrative	$	2,378	$	4,091	$	1,166
Research and development		1,753		1,182		552
Total share-based compensation	$	4,131	$	5,273	$	1,718

Schedule of RSA grant activity


	Number of	Weighted-Average
	Shares	Fair Value (per share)

Non‑vested at December 31, 2015	348,093	$	0.09
Granted	—	$	—
Vested	(344,084)	$	0.09
Non‑vested at December 31, 2016	4,009	$	0.21
Granted	—	$	—
Vested	(4,009)	$	0.21
Non‑vested at December 31, 2017	—	$	—
Granted	—	$	—
Vested	—	$	—
Non‑vested at December 31, 2018	—	$	—

Schedule of stock option plan activity


				Weighted‑
		Weighted		Average
		Average		Remaining	Aggregate
	Number of	Exercise		Contractual	Intrinsic
	Options	Price		Term (years)	Value(1)

Outstanding at December 31, 2015	302,842	$	2.43	9.60	$	1,031,000
Granted	2,023,700	$	10.07	—		—
Exercised	—	$	—	—		—
Forfeited/Cancelled	(83,742)	$	9.12	—		—
Outstanding at December 31, 2016	2,242,800	$	9.07	9.48	$	(2,759,000)
Granted	248,500	$	12.24	—		—
Exercised	(23,910)	$	1.92	—		—
Forfeited/Cancelled	(3,250)	$	1.34	—		—
Outstanding at December 31, 2017	2,464,140	$	9.46	8.58	$	(3,715,000)
Granted	822,000	$	8.24	—		—
Exercised	(40,398)	$	2.25	—		—
Forfeited/Cancelled	(444,968)	$	10.61	—		—
Outstanding at December 31, 2018	2,800,774	$	9.02	7.96	$	(22,994,287)
Vested and exercisable at December 31, 2018	1,812,181	$	9.15	7.72	$	(15,120,294)
Vested and expected to vest at December 31, 2018	2,800,774	$	9.02	7.96	$	(22,994,287)

⁽¹⁾

Schedule of weighted-average assumptions, option-pricing model


	Year Ended
	December 31,
	2018			2017			2016

Expected stock price volatility		66.3	%		65.8	%		71.447	%
Expected life of options (years)		5.8			5.9			6.02
Expected dividend yield		0	%		0	%		0	%
Risk free interest rate		2.7	%		2.0	%		1.2	%

Net Loss Per Common Share (Tables)

12 Months Ended

Dec. 31, 2018

Net Loss Per Common Share

Schedule of computation of basic and diluted loss per share

The following table sets forth the computation of basic and diluted loss per share as of December 31, 2018, 2017 and 2016 (in thousands, except share and per share amounts):


	Year Ended
	2018		2017		2016
Numerator:
Net loss	$	(23,637)	$	(33,415)	$	(14,586)
Adjustment to redemption value on Series A convertible preferred stock		—		—		(366)
Net loss attributed to common stock holders	$	(23,637)	$	(33,415)	$	(14,952)
Denominator:
Basic and diluted weighted average common shares outstanding		13,805,552		10,349,136		5,809,396
Basic and diluted net loss per share	$	(1.71)	$	(3.23)	$	(2.57)

Schedule of potential common shares not considered in computation of diluted net loss per share


	Year Ended
	2018	2017	2016
Stock options	2,800,774	2,464,140	2,242,800
Restricted stock awards	—	—	4,009
Warrants	1,014,204	978,204	—
Series A	—	—	—
Convertible notes	—	—	—

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Taxes

Schedule of statutory federal income tax rate to the provision (benefit)


	For the Year Ended December 31,
	2018		2017		2016
Income tax (benefit) provision at federal statutory rate	(21.0)	%	(34.0)	%	(34.0)	%
Valuation allowance	28.2		21.0		40.2
U.S. tax reform	-		20.2		—
State income tax, net of federal benefit	(4.8)		(4.1)		(4.7)
Convertible notes	—		—		1.1
Research credits	(3.0)		(3.6)		(4.0)
Other	0.6		0.5		1.4
Effective tax rate	—	%	—	%	—	%

Schedule of deferred tax assets and liabilities

Significant components of the Company’s deferred tax assets and liabilities are summarized in the tables below as of (in thousands):


	Year Ended December 31,
Deferred tax assets:	2018		2017
Federal and state operating loss carryforwards	$	5,073	$	3,349
Research and development costs deferral election		12,264		8,881
Acquired intangibles		235		235
Term loan		—		33
Charitable contributions		21		14
Stock-based compensation		2,618		1,722
Research and development credit carryforwards		2,655		1,947
		22,866		16,181
Valuation allowance		(22,866)		(16,181)
Total deferred tax assets, net of valuation allowance		—		—
Deferred tax liabilities:
Total deferred tax liabilities		—		—
Net deferred tax assets	$	—	$	—

Quarterly Data (Tables)

12 Months Ended

Dec. 31, 2018

Supplementary Data — Quarterly Financial Data (unaudited).

Schedule of unaudited consolidated quarterly financial information


	Three Months Ended
	December 31,		September 30,		June 30,		March 31,
	2018 (B)		2018 (B)		2018		2018
	(in thousands, except per share amounts)
Operating expenses:
General and administrative	$	1,468	$	2,364	$	2,574	$	2,087
Research and development		1,833		3,542		3,960		4,977
Total operating expenses		3,301		5,906		6,534		7,064
Loss from operations		(3,301)		(5,906)		(6,534)		(7,064)
Interest expense		(178)		(172)		(144)		(160)
Other expense		(177)		(1)		—		—
Loss before income taxes		(3,656)		(6,079)		(6,678)		(7,224)
Provision (benefit) for income taxes		—		—		—		—
Net loss		(3,656)		(6,079)		(6,678)		(7,224)
Other comprehensive loss, net of tax		—		—		—		—
Comprehensive loss	$	(3,656)	$	(6,079)	$	(6,678)	$	(7,224)
Net loss per share:
Basic and diluted (A)	$	(0.26)	$	(0.43)	$	(0.47)	$	(0.58)

	Three Months Ended
	December 31,		September 30,		June 30,		March 31,
	2017		2017		2017		2017
	(in thousands, except per share amounts)
Operating expenses:
General and administrative	$	1,487	$	2,050	$	4,678	$	2,223
Research and development		5,080		6,489		5,837		5,280
Total operating expenses		6,567		8,539		10,515		7,503
Loss from operations		(6,567)		(8,539)		(10,515)		(7,503)
Interest (expense) income		(179)		(132)		13		12
Other expense		—		—		—		(5)
Loss before income taxes		(6,746)		(8,671)		(10,502)		(7,496)
Provision (benefit) for income taxes		—		—		—		—
Net loss		(6,746)		(8,671)		(10,502)		(7,496)
Other comprehensive loss, net of tax		—		—		—		—
Comprehensive loss	$	(6,746)	$	(8,671)	$	(10,502)	$	(7,496)
Net loss per share:
Basic and diluted (A)	$	(0.63)	$	(0.82)	$	(0.99)	$	(0.79)

^(A)

Net loss per share for the year may not equal the sum of the four historical quarters loss per share due to changes in weighted-average shares outstanding.

^(B)

The Company and Basis of Presentation (IPO and Capital Requirements) (Details) - USD ($) $ / shares in Units, $ in Thousands				12 Months Ended
	Feb. 12, 2018	Sep. 08, 2016	Aug. 04, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Aug. 03, 2016
Sale of Stock
Issuance of stock (in shares)	3,592,858
Other offering expenses				$ 2,091	$ 1,287	$ 3,963
Common stock, shares authorized				100,000,000	100,000,000		100,000,000
Preferred stock, shares authorized				10,000,000	10,000,000		10,000,000
Common stock, par value (in dollar per share)				$ 0.001	$ 0.001
Preferred stock, par value (in dollar per share)				$ 0.001	$ 0.001		$ 0.001
IPO
Sale of Stock
Issuance of stock (in shares)			3,000,000
Share price (in dollars per share)			$ 10.00
Net proceeds			$ 26,100
Underwriting discounts and commissions		$ 2,100
Other offering expenses		$ 2,100
Overallotment
Sale of Stock
Issuance of stock (in shares)	450,000	27,755
Share price (in dollars per share)		$ 10.00

Summary of Significant Accounting Policies (Details)		12 Months Ended
Summary of Significant Accounting Policies (Details)	Aug. 10, 2016 shares	Dec. 31, 2018 USD ($) segment shares	Jan. 01, 2019 USD ($)	Dec. 31, 2017 shares	Mar. 31, 2015 shares
Income Taxes
Provision (benefit) for income taxes		$ 0
Segment Information
Number of operating segment \| segment		1
ASU 2016-02 \| Adjustment \| Minimum
Recent Accounting Pronouncements
Right of use asset			$ 100,000
Lease liability			100,000
ASU 2016-02 \| Adjustment \| Maximum
Recent Accounting Pronouncements
Right of use asset			200,000
Lease liability			$ 200,000
Series A
Convertible Preferred Stock
Convertible Preferred stock, share issued \| shares					745,637
Shares converted \| shares	827,205
Convertible Preferred stock, share outstanding \| shares		0		0

Accrued Liabilities (Details) $ in Thousands	Dec. 31, 2018 USD ($)	Sep. 18, 2018 employee	Dec. 31, 2017 USD ($)
Accrued Liabilities
Accrued compensation and other payroll liabilities	$ 137		$ 306
Workforce reduction severance	100
Legal costs	106		91
Accrued interest	43		38
Other research and development expenses	135		522
Other general and administrative expenses	17		53
Total	$ 438		$ 1,010
Number of employees \| employee		5
Workforce (as a percentage)		33.00%

Debt - Term Loan (Details)			1 Months Ended	3 Months Ended								12 Months Ended
Debt - Term Loan (Details)	Jan. 28, 2019 USD ($)	Jul. 31, 2018 USD ($) $ / shares shares	Jul. 31, 2017 USD ($)	Dec. 31, 2018 USD ($) tranche $ / shares shares	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($) tranche $ / shares shares	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Debt
Purchase of additional common stock through warrants \| shares				993,204								993,204
Term of warrants				5 years								5 years
Exercise price of warrant \| $ / shares				$ 10.40								$ 10.40
Interest (expense) income				$ (178,000)	$ (172,000)	$ (144,000)	$ (160,000)	$ (179,000)	$ (132,000)	$ 13,000	$ 12,000	$ (654,000)	$ (286,000)	$ 114,000
Outstanding borrowings								$ 8,683,000					8,683,000
Risk Free Interest Rate
Debt
Warrant measurement		2.96		2.0								2.0
Price Volatility
Debt
Warrant measurement		66		65.1								65.1
Expected Term
Debt
Term of warrants		10 years		5 years								5 years
Expected Dividend Rate
Debt
Warrant measurement		0		0								0
Minimum
Debt
Interest rate (as a percentage)				4.50%								4.50%
Debt issue costs				$ 4.25								$ 4.25
Maximum
Debt
Interest rate (as a percentage)				5.50%								5.50%
Debt issue costs				$ 4.5								$ 4.5
Term Loan
Debt
Principal amount				$ 15,000,000								$ 15,000,000
Number of tranches \| tranche				3								3
Interest rate (as a percentage)				5.00%								5.00%
Cash security (as a percentage)												100.00%
Unrestricted cash				$ 18,000,000								$ 18,000,000
Debt discount amortized as interest expenses			$ 100,000
Interest (expense) income		$ 33,000										500,000	$ 300,000
Term Loan \| Subsequent Event
Debt
Debt discount amortized as interest expenses	$ 800,000
Outstanding borrowings	$ 8,900,000
Term Loan \| SVB
Debt
Final payment fee (as a percentage)	10.00%
Success fee (as a percentage)	3.50%
Purchase of additional common stock through warrants \| shares		36,000
Term of warrants		10 years
Exercise price of warrant \| $ / shares		$ 7.47
Additional paid in capital upon issuance with offset of loan discount		$ 200,000
Term Loan \| SVB \| Subsequent Event
Debt
Debt issue costs	$ 1,000,000
Initial Tranche
Debt
Principal amount				10,000,000								10,000,000
Debt discount amortized as interest expenses												2,000
Legal fees incurred												20,000
Initial Tranche \| SVB
Debt
Fee recorded as discount												10,000
Third Tranche Available Through November 2018
Debt
Principal amount				$ 5,000,000								$ 5,000,000

Debt - Term Loan Minimum Aggregate Future Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Minimum aggregate future payments
Current portion	$ (9,437)	$ (1,355)
Long-term portion		$ 8,683
Term Loan
Minimum aggregate future payments
2019	4,826
2020	4,579
2021	1,370
Total minimum payments	10,775
Amount representing interest and discounts	(1,338)
Present value of minimum payments	9,437
Current portion	$ (9,437)

Debt - Interim Notes (Details)				1 Months Ended			3 Months Ended								12 Months Ended
Debt - Interim Notes (Details)	Aug. 10, 2016 USD ($) shares	Feb. 29, 2016 USD ($) $ / shares	Jul. 31, 2015 USD ($) shares	Apr. 30, 2016 USD ($) $ / shares	Feb. 29, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($) $ / shares	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Debt
Qualified Financing threshold for debt conversion			$ 5,000,000
Debt redemption price			200.00%
Conversion ratio			115
Interest (expense) income							$ (178,000)	$ (172,000)	$ (144,000)	$ (160,000)	$ (179,000)	$ (132,000)	$ 13,000	$ 12,000	$ (654,000)	$ (286,000)	$ 114,000
Interim Notes
Debt
Proceeds from issuance of convertible notes		$ 200,000	$ 2,800,000	$ 5,000,000	$ 200,000	$ 2,700,000
Shares converted \| shares	1,656,807		1,656,807
Convertible interest rate (as a percentage)		8.00%	8.00%		8.00%
Qualified Financing threshold for debt conversion				5,000,000
Principal amount		$ 5,600,000		10,600,000	$ 5,600,000	$ 5,500,000
Debt issue costs				$ 10,000
Conversion ratio				125	115
Conversion price \| $ / shares		$ 6.70585		$ 6.70585	$ 6.70585	$ 6.70585
Premium conversion derivative							$ 0				$ 0				$ 0	$ 0	$ 0
Interest (expense) income	$ 200,000

License Agreement (Details) - USD ($)			1 Months Ended	12 Months Ended
License Agreement (Details) - USD ($)	Feb. 12, 2018	Mar. 31, 2015	Mar. 31, 2015	Dec. 31, 2018	Dec. 31, 2016
License Agreements
Issuance of stock (in shares)	3,592,858
Issuance of common stock from offering				$ 25,150,000	$ 30,278,000
Milestones or royalty payments triggered				$ 0
Common Stock
License Agreements
Issuance of stock (in shares)				3,592,858	3,027,755
Issuance of common stock from offering				$ 4,000	$ 3,000
Pfizer, Inc. \| License Agreement
License Agreements
Percentage of shares of common stock offering issued to Pfizer		15.00%
Number of years after the first commercial sale			P5Y
Notice period			90 days
Pfizer, Inc. \| License Agreement \| Common Stock
License Agreements
Issuance of stock (in shares)		675,250
Issuance of common stock from offering		$ 900,000
Pfizer, Inc. \| License Agreement \| Common Stock \| Minimum \| Pfizer, Inc.
License Agreements
Ownership by Pfizer		5.00%	5.00%
Pfizer, Inc. \| License Agreement \| Milestone Payments \| Maximum \| Pfizer, Inc.
License Agreements
Potential payments upon achievement of certain milestones		$ 37,000,000	$ 37,000,000

Convertible Series A Preferred Stock (Details) - USD ($)			12 Months Ended
	Aug. 10, 2016	Mar. 31, 2015	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Convertible Series A Preferred Stock
Dividends deemed payable and accrued				$ 0	$ 0
Series A Convertible Preferred Stock.
Convertible Series A Preferred Stock
Issuance of convertible Series A preferred stock (shares)		745,637
Original issue price, per share		$ 6.70585
Aggregate consideration, cash and noncash		$ 5,000,000
Cash proceeds from issuance of Series A preferred		1,500,000
Shares converted	827,205
Dividend rate			8.00%
Liquidation preference, per share			$ 6.70585
Series A Convertible Preferred Stock. \| Minimum
Convertible Series A Preferred Stock
Liquidation preference upon transfer of voting power, percentage			50.00%
Percentage of outstanding shares which may require the Company to redeem shares			80.00%
Redemption price, as a percent of liquidation preference			150.00%
Series A Convertible Preferred Stock. \| Convertible Notes
Convertible Series A Preferred Stock
Noncash consideration received, debt converted into stock		$ 3,500,000
Conversion price percentage of principal and unpaid accrued interest		125.00%

Stockholders’ Equity (Deficit) (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended	12 Months Ended
	Feb. 12, 2018	Mar. 15, 2017	Sep. 08, 2016	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Common Stock
Common stock, shares issued					14,265,411	10,633,042
Issuance of common stock from offering (in shares)	3,592,858
Gross proceeds					$ 25,150		$ 30,278
Offering costs					$ 2,091	$ 1,287	$ 3,963
Follow On Offering
Common Stock
Common stock, shares issued	3,142,858
Issuance of common stock from offering (in shares)				3,592,858
Net proceeds	$ 23,100
Offering costs	$ 2,100
Share price (in dollars per share)	$ 7.00
Private placement
Common Stock
Common stock, shares issued		1,324,256
Issuance of common stock from offering (in shares)		1,324,256
Price per issue and sold units		$ 9.47
Gross proceeds		$ 12,500				$ 8,979
Number of shares per unit		1
Number of warrants per unit		0.75
Net proceeds		$ 11,300
Offering costs		$ 1,300
Overallotment
Common Stock
Issuance of common stock from offering (in shares)	450,000		27,755
Share price (in dollars per share)			$ 10.00

Share-Based Compensation - Restricted Stock (Details) - Restricted stock awards - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restricted Stock Awards
Forfeited (in shares)	0	0	0
RSA grant activity [Rollforward], Number of Shares
Non‑vested , Beginning Balance (in shares)		4,009	348,093
Vested (in shares)		(4,009)	(344,084)
Non‑vested , Ending Balance (in shares)			4,009
RSA grant activity [Rollforward], Weighted-Average Fair Value (per share)
Non‑vested , Beginning Balance (per share)		$ 0.21	$ 0.09
Vested (per share)		$ 0.21	0.09
Non‑vested , Ending Balance (per share)			$ 0.21
Minimum
Restricted Stock Awards
Vesting period	6 months
Maximum
Restricted Stock Awards
Vesting period	24 months

Share-Based Compensation - Stock Options (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 01, 2019	Sep. 30, 2016	Apr. 30, 2016	Apr. 30, 2015
Stock Options, Additional Disclosures
Unrecognized share-based compensation cost	$ 3,900,000
Unrecognized share-based compensation - Weighted average period	1 year 6 months
2015 Plan
Stock Options, Additional Disclosures
Vested	709,521	861,645	276,248
A&R 2015 Plan
Stock Options, Additional Disclosures
Common stock reserved for issuance (in shares)	415,077	0
Number of years common shares automatically increase	10 years
Percentage of company's fully diluted shares	20.00%
Inducement Plan
Stock Options, Additional Disclosures
Common stock reserved for issuance (in shares)						300,000
Employees, Directors And Consultants \| 2015 Plan
Stock Options, Additional Disclosures
Common stock reserved for issuance (in shares)								320,615
Employees, Directors And Consultants \| A&R 2015 Plan
Stock Options, Additional Disclosures
Common stock reserved for issuance (in shares)							2,400,000
Employees, Directors And Consultants \| Inducement Plan
Stock Options, Additional Disclosures
Vesting period	4 years
Officers, Directors, And Employees \| A&R 2015 Plan
Stock Options, Additional Disclosures
Granted (in shares)	772,000	150,500	1,825,700
Officers And Employees \| Inducement Plan
Stock Options, Additional Disclosures
Granted (in shares)	50,000	98,000	198,000
Minimum \| Employees, Directors And Consultants \| A&R 2015 Plan
Stock Options, Additional Disclosures
Vesting period	3 years
Maximum \| Employees, Directors And Consultants \| A&R 2015 Plan
Stock Options, Additional Disclosures
Vesting period	4 years
Stock options
Stock Options, Additional Disclosures
Outstanding, Number, Beginning Balance (in shares)	2,464,140	2,242,800	302,842
Granted (in shares)	822,000	248,500	2,023,700
Exercised (in shares)	(40,398)	(23,910)
Forfeited/Cancelled (in shares)	(444,968)	(3,250)	(83,742)
Outstanding, Number, Ending Balance (in shares)	2,800,774	2,464,140	2,242,800	302,842
Vested and exercisable (in shares)	1,812,181
Vested and expected to vest (in shares)	2,800,774
Outstanding, Weighted Average Exercise Price, Beginning Balance (in dollars per share)	$ 9.46	$ 9.07	$ 2.43
Granted (in dollars per share)	8.24	12.24	10.07
Exercise price (in dollars per share)	2.25	1.92
Forfeited/Cancelled (in dollars per share)	10.61	1.34	9.12
Outstanding, Weighted Average Exercise Price, Ending Balance (in dollars per share)	9.02	$ 9.46	$ 9.07	$ 2.43
Vested and exercisable (in dollars per share)	9.15
Vested and expected to vest (in dollars per share)	$ 9.02
Options, Outstanding, Weighted Average Remaining Contractual Term (years)	7 years 11 months 16 days	8 years 6 months 29 days	9 years 5 months 23 days	9 years 7 months 6 days
Vested and exercisable (years)	7 years 8 months 19 days
Vested and expected to vest (years)	7 years 11 months 16 days
Options, Outstanding, Aggregate Intrinsic Value	$ (22,994,287)	$ (3,715,000)	$ (2,759,000)	$ 1,031,000
Vested and exercisable	(15,120,294)
Vested and expected to vest	$ (22,994,287)
Common stock aggregate intrinsic value of exercise price	$ 0.81	$ 7.95	$ 7.84
Weighted average fair value per share of options granted	5.07	7.35	6.37
Weighted average fair value per share of options vested	$ 6.15	$ 5.99	$ 4.59
Forfeited	444,968	3,250	83,742
Forecast \| A&R 2015 Plan
Stock Options, Additional Disclosures
Common stock reserved for issuance (in shares)					501,001

Share-Based Compensation - 2016 Employee Stock Purchase Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Apr. 30, 2016	Apr. 30, 2015
2016 Employee Stock Purchase Plan
Expected stock price volatility	66.30%	65.80%	71.447%
Expected life of options (years)	5 years 9 months 18 days	5 years 10 months 24 days	6 years 7 days
Expected dividend yield	0.00%	0.00%	0.00%
Risk free interest rate	2.70%	2.00%	1.20%
Unrecognized share-based compensation
Unrecognized share-based compensation cost	$ 3.9
Unrecognized share-based compensation - Weighted average period	1 year 6 months
ESPP
2016 Employee Stock Purchase Plan
Granted (in shares)	0
Common stock reserved for issuance (in shares)					150,000
A&R 2015 Plan
2016 Employee Stock Purchase Plan
Common stock reserved for issuance (in shares)	415,077	0
Inducement Plan
2016 Employee Stock Purchase Plan
Common stock reserved for issuance (in shares)				300,000
2015 Plan
Number of Options
Vested	709,521	861,645	276,248
Employees, Directors And Consultants \| A&R 2015 Plan
2016 Employee Stock Purchase Plan
Common stock reserved for issuance (in shares)					2,400,000
Number of Options
Available for future issuance	701,261
Employees, Directors And Consultants \| Inducement Plan
2016 Employee Stock Purchase Plan
Vesting period	4 years
Number of Options
Available for future issuance	701,261
Employees, Directors And Consultants \| 2015 Plan
2016 Employee Stock Purchase Plan
Common stock reserved for issuance (in shares)						320,615

Income Taxes - Reconciliation of income tax (Details)	12 Months Ended
Income Taxes - Reconciliation of income tax (Details)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of income tax:
Income tax (benefit) provision at federal statutory rate (as a percent)	(21.00%)	(34.00%)	(34.00%)
Valuation allowance	28.20%	21.00%	40.20%
U.S. tax reform (as a percent)		20.20%
State income tax, net of federal benefit (as a percent)	(4.80%)	(4.10%)	(4.70%)
Convertible notes (as a percent)			1.10%
Research credits (as a percent)	(3.00%)	(3.60%)	(4.00%)
Other (as a percent)	0.60%	0.50%	1.40%
Effective tax rate (as a percent)	0.00%	0.00%	0.00%

Income Taxes -Significant components of deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Federal and state operating loss carryforwards	$ 5,073	$ 3,349
Research and development costs deferral election	12,264	8,881
Acquired intangibles	235	235
Term loan		33
Charitable contributions	21	14
Stock-based compensation	2,618	1,722
Research and development credit carryforwards	2,655	1,947
Total deferred tax assets	22,866	16,181
Valuation allowance	$ (22,866)	$ (16,181)

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating loss carryforwards
Deferred Tax Assets, Valuation Allowance, Total	$ 22,866,000	$ 16,181,000
Federal net operating loss carryforwards	4,200,000	2,800,000
Research and development credit carryforwards	2,655,000	1,947,000
State net operating loss carryforwards	900,000	600,000
State research credit carryforwards	$ 100,000	45,000
Income tax:
Threshold percentage of shareholders ownership change	5.00%
Minimum increase in ownership percentage annual limitation may result in expiration of NOL and credits	50.00%
Period for testing percentage of ownership change	36 months
Uncertain tax positions	$ 0	0
Interest or penalties	$ 0	$ 0

Quarterly Data (Details) - USD ($)	3 Months Ended								12 Months Ended
Quarterly Data (Details) - USD ($)	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Sep. 18, 2018
Operating expenses:
General and administrative	$ 1,468,000	$ 2,364,000	$ 2,574,000	$ 2,087,000	$ 1,487,000	$ 2,050,000	$ 4,678,000	$ 2,223,000	$ 8,493,000	$ 10,438,000	$ 5,956,000
Research and development	1,833,000	3,542,000	3,960,000	4,977,000	5,080,000	6,489,000	5,837,000	5,280,000	14,312,000	22,686,000	8,740,000
Total operating expenses	3,301,000	5,906,000	6,534,000	7,064,000	6,567,000	8,539,000	10,515,000	7,503,000	22,805,000	33,124,000	14,696,000
Loss from operations	(3,301,000)	(5,906,000)	(6,534,000)	(7,064,000)	(6,567,000)	(8,539,000)	(10,515,000)	(7,503,000)	(22,805,000)	(33,124,000)	(14,696,000)
Interest (expense) income	(178,000)	(172,000)	(144,000)	(160,000)	(179,000)	(132,000)	13,000	12,000	(654,000)	(286,000)	114,000
Other income	(177,000)	(1,000)						(5,000)	(178,000)	(5,000)	(4,000)
Loss before income taxes	(3,656,000)	(6,079,000)	(6,678,000)	(7,224,000)	(6,746,000)	(8,671,000)	(10,502,000)	(7,496,000)	(23,637,000)	(33,415,000)	(14,586,000)
Provision (benefit) for income taxes									0
Net loss	(3,656,000)	(6,079,000)	(6,678,000)	(7,224,000)	(6,746,000)	(8,671,000)	(10,502,000)	(7,496,000)	(23,637,000)	(33,415,000)	(14,586,000)
Comprehensive loss	(3,656,000)	(6,079,000)	(6,678,000)	(7,224,000)	(6,746,000)	(8,671,000)	(10,502,000)	(7,496,000)	(23,637,000)	(33,415,000)	(14,586,000)
Comprehensive loss	$ (3,656,000)	$ (6,079,000)	$ (6,678,000)	$ (7,224,000)	(6,746,000)	(8,671,000)	(10,502,000)	(7,496,000)	(23,637,000)	$ (33,415,000)	(14,586,000)
Adjustment to redemption value on Series A convertible preferred stock					$ (0.63)	$ (0.82)	$ (0.99)	$ (0.79)			$ (366,000)
Workforce (as a percentage)												33.00%
Workforce reduction related expenses									$ 1,600,000
Net loss per share:
Basic and diluted	$ (0.26)	$ (0.43)	$ (0.47)	$ (0.58)					$ (1.71)	$ (3.23)	$ (2.57)
General and administrative
Operating expenses:
Workforce reduction related expenses									$ 600,000
Research and development
Operating expenses:
Workforce reduction related expenses									$ 1,000,000

Related Party Transactions - IPO and Private Placement (Details) $ in Thousands				3 Months Ended	12 Months Ended
	Feb. 12, 2018 shares	Mar. 15, 2017 USD ($) person director shares	Aug. 04, 2016 USD ($) person director shares	Mar. 31, 2018 USD ($) item shares	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Related Party Transaction [Line Items]
Issuance of stock (in shares) \| shares	3,592,858
Gross proceeds \| $					$ 25,150		$ 30,278
IPO
Related Party Transaction [Line Items]
Number of shares sold to 5 officers and 3 board members \| shares			154,450
Number of officers \| person			5
Number of board members \| director			3
Proceeds from issuance of shares to 5 officers and 3 board members \| $			$ 1,500
Number of shares sold to 1 investor related to 1 of the Company's directors \| shares			500,000
Number of investor related to 1 of the Company’s directors \| person			1
Number of shares sold to 14 investors who are related to 5 officers of the Company \| shares			47,000
Proceeds from issuance of shares to 14 investors who are related to 5 officers of the Company \| $			$ 500
Number of investors related to 5 officers of the company \| person			14
Issuance of stock (in shares) \| shares			3,000,000
Proceeds from issuance of shares to 1 investor related to 1 of the Company's directors \| $			$ 5,000
Private placement
Related Party Transaction [Line Items]
Issuance of stock (in shares) \| shares		1,324,256
Gross proceeds \| $		$ 12,500				$ 8,979
Follow On Offering
Related Party Transaction [Line Items]
Number of officers \| item				1
Number of shares sold to 1 investor				14,286
Proceeds from issuance of shares to 1 investor \| $				$ 100
Number of shares sold to 1 investor who is an affiliate of 1 officer and board member				71,429
Proceeds from issuance of shares to 1 investor who is an affiliate of 1 officer and board member \| $				$ 500
Issuance of stock (in shares) \| shares				3,592,858
Number of investor \| item				1
Three Board Members \| Private placement
Related Party Transaction [Line Items]
Number of board members \| director		3
Issuance of stock (in shares) \| shares		56,678
Gross proceeds \| $		$ 500
One Board Member \| Private placement
Related Party Transaction [Line Items]
Number of board members \| director		1
Issuance of stock (in shares) \| shares		52,798
Gross proceeds \| $		$ 500
Number of investor \| person		1

Statements of Changes in Convertible Preferred Stock and Stockholders’ Equity (Deficit) - Temporary Equity - 12 months ended Dec. 31, 2016 $ in Thousands	Series A Convertible Preferred Stock. USD ($) shares
Temporary equity, balance at beginning of period at Dec. 31, 2015	$ 7,953
Temporary equity, balance at beginning of period (shares) at Dec. 31, 2015 \| shares	745,637
Increase (Decrease) in Temporary Equity
Redemption value adjustment - Series A preferred stock	$ 366
Conversion of Series A preferred stock, amount converted	$ (8,319)
Conversion of Series A preferred stock, shares converted (shares) \| shares	(745,637)
Temporary equity, balance at end of period at Dec. 31, 2016	$ 0
Temporary equity, balance at end of period (shares) at Dec. 31, 2016 \| shares	0

License Agreement	12 Months Ended
License Agreement	Dec. 31, 2018
License Agreement
License Agreement	6. License Agreement The Company is party to the Pfizer Agreement, as amended on August 2, 2018, for a worldwide exclusive license to certain patent rights and a non-exclusive royalty bearing right and license to certain related data to make, use, develop, commercialize, import and otherwise exploit the clinical product candidate gemcabene. Pfizer retains the right to make, use and import gemcabene solely for internal research purposes. In partial exchange for the rights granted by Pfizer, the Company agreed to issue shares of its common stock to Pfizer representing 15% of the Company’s fully diluted capital at the close of its first arms‑length Series A financing, which occurred on March 31, 2015. The Company agreed to make milestone payments totaling up to $37 million upon the achievement of certain milestones, including the first new drug application (or its foreign equivalent) in any country, regulatory approval in each of the United States, Europe and Japan, the first anniversary of the first regulatory approval in any country, and upon achieving certain aggregate sales levels of gemcabene. Future milestone payments under the Pfizer Agreement, if any, are not expected to begin for at least several years and extend over a number of subsequent years. The Company also agreed to pay Pfizer tiered royalties on a country‑by‑country basis based upon the annual amount of net sales, as specified in the Pfizer Agreement, until the later of: (a) five (5) years after the first commercial sale in such country; (b) the expiration of all regulatory or data exclusivity for gemcabene in such country; and (c) the expiration or abandonment of the last valid claim of the licensed patents, including any patent term extensions or supplemental protection certificates in such country (collectively, the Royalty Term). Under the Pfizer Agreement, the Company is obligated to use commercially reasonable efforts to develop and commercialize gemcabene. On March 31, 2015, upon the closing of the Series A preferred stock financing, the Company issued 675,250 shares of its common stock, at a fair market value of $0.9 million, to Pfizer in connection with the first equity payment, pursuant to which Pfizer became the owner of more than 5% of the Company’s capital stock. The transaction was recorded as acquired in‑process research and development expenses based on the fair value of the common shares issued since no processes or activities that would constitute a “business” were acquired and none of the rights and underlying assets acquired had alternative future uses or reached a stage of technological feasibility. None of the other milestone or royalty payments were triggered as of December 31, 2018. The Pfizer Agreement will expire upon expiration of the last Royalty Term. On expiration (but not earlier termination), the Company will have a perpetual, exclusive, fully paid-up, royalty-free license under the licensed patent rights and related data to make, use, develop, commercialize, import and otherwise exploit the clinical product candidate gemcabene. Either party may terminate the Pfizer Agreement for the other party’s material breach following a cure period or immediately upon certain insolvency events relating to the other party. Pfizer may immediately terminate the Pfizer Agreement in the event that (i) the Company or any of its affiliates or sublicenses contests or challenges, or supports or assists any third party to contest or challenge, Pfizer’s ownership of or rights in, or the validity, enforceability or scope of any of the patents licensed under the Pfizer Agreement or (ii) the Company or any of its affiliates or sublicensees fails to achieve the first commercial sale in at least one country by April 16, 2024. Furthermore, upon termination of the Pfizer Agreement by Pfizer for any of the foregoing reasons, the Company grants Pfizer a non-exclusive, fully paid-up, royalty free, worldwide, transferrable, perpetual and irrevocable license to use any intellectual property rights arising from the development or commercialization of gemcabene by the Company and any trademarks identifying gemcabene and agrees to transfer regulatory filings and approvals to Pfizer or permit Pfizer to cross-reference and rely on such regulatory filings and approvals for gemcabene. The Company may terminate the License Agreement for convenience upon 90 days’ written notice and payment of an early termination fee.

Stockholders’ Equity (Deficit)	12 Months Ended
Stockholders’ Equity (Deficit)	Dec. 31, 2018
Stockholders’ Equity (Deficit)
Stockholders’ Equity (Deficit)	8. Stockholders’ Equity (Deficit) Common Stock The Company had 14,265,411 and 10,633,042 shares of its common stock issued and outstanding as of December 31, 2018 and December 31, 2017, respectively. Voting, dividend and liquidation rights of the holders of the common stock are subject to the Company’s articles of incorporation, corporate bylaws and underlying shareholder agreements. In the first quarter of 2018, the Company completed the Follow-On Offering of 3,592,858 shares of common stock which includes 450,000 shares of common stock purchased by the underwriters upon the partial exercise of their overallotment option, at the public offering price of $7.00 per share. The Company received net proceeds of approximately $23.1 million after deducting underwriting discounts and commissions and offering expenses. The costs incurred related to the Follow-On Offering were $2.1 million through December 31, 2018. On March 15, 2017, the Company issued and sold 1,324,256 units at a price of $9.47 per unit for gross proceeds of approximately $12.5 million in connection with the Private Placement. Each unit consisted of one share of the Company’s common stock and a warrant to purchase 0.75 shares of common stock. The Company received net proceeds of approximately $11.3 million after deducting underwriting discounts and commissions and offering expenses. Offering costs incurred related to the 2017 Private Placement were $1.3 million. Warrants In connection with the Private Placement, the Company issued warrants to the investors participating in the financing to purchase an additional 993,204 shares of common stock. The warrants have a term of five years and were exercisable immediately upon issuance with an exercise price equal to $10.40 per share. The warrants were classified as additional paid-in capital and recorded based on their relative fair value to the underlying common shares issued in the Private Placement. The fair market value of the warrants was approximately $4.9 million. The warrants were valued using the Black-Scholes pricing model with the following assumptions: a risk-free interest rate of 2.0%, a contractual term of five years, zero dividend yield and a volatility factor of 65.1%. In connection with the First Amendment, the Company issued a warrant to SVB to purchase an additional 36,000 shares of common stock on July 31, 2018 (See Note 4 – Debt). During the years ended December 31, 2018 and 2017, zero and 15,000 warrants were exercised, respectively. As of December 31, 2018 and December 31, 2017, warrants to purchase 1,014,204 and 978,204 shares of common stock were outstanding, respectively. Dividend Rights Common stock holders are entitled to receive dividends at the sole discretion of the board of directors of the Company. There have been no dividends declared on common stock as of December 31, 2018. Voting Rights The holders of common stock are entitled to one vote for each share of common stock along with all other classes and series of stock of the Company on all actions to be taken by the stockholders of the Company, including actions that would amend the certificate of incorporation of the Company to increase the number of authorized shares of the common stock. Liquidation Rights In the event of any liquidation, dissolution, or winding‑up of the Company, the holders of common stock shall be entitled to share in the remaining assets of the Company available for distribution post preferential distributions made to holders of the Company’s preferred stock. There was no preferred stock outstanding as of December 31, 2018 and 2017. Deferred Offering Costs There were $21,000 of deferred offering costs capitalized at December 31, 2017 related to the Private Placement. There were no deferred offering costs capitalized as of December 31, 2018.

Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2018
Related Party Transactions
Related Party Transactions	14. Related Party Transactions The Company rented an office in Northville, Michigan from an LLC owned by two officers under short‑term agreements during the years ended December 31, 2017, 2016 and 2015. The original facility lease, as amended, was cancelled and replaced with a cancellable lease agreement in August 2016 for limited use of office space in the same Northville location. The new lease agreement became effective in August 2016 and expired in September 2017. Rent expense under the related party agreements was nominal during the year ended December 31, 2017 and was $21,000 and $23,000 during the years ended December 31, 2016 and 2015, respectively. There was no rent expense under the related party agreements during the year ended December 31, 2018. In February 2016, the Company issued an additional $0.2 million of Interim Notes, which included two notes issued to two board members (or entities they control) in the amount of $81,000. The February 2016 Interim Note issuances also included a $20,000 note to an investor who is related to an officer of the Company. The Interim Note were converted upon the close of the IPO. In April 2016, the Company issued an additional $5.0 million of Interim Notes, which included two notes to investors who were related to two of the Company’s officers in the aggregate amount of $0.2 million. The April 2016 Interim Notes issuances also included three notes to investors who were related to three of the Company’s directors in the aggregate amount of $2.3 million. The Interim Note were converted upon the close of the IPO. The IPO included 154,450 shares sold to 5 officers and 3 board members, totaling $1.5 million. In addition, 500,000 shares were sold to 1 investor who is related to 1 of the Company’s directors, totaling $5.0 million, and 47,000 shares totaling $0.5 million were sold to 14 investors who are related to 5 officers of the Company. The Private Placement included 56,678 units sold to three board members, for aggregate proceeds totaling approximately $0.5 million, and 52,798 units sold to one investor who was related to one board member, for proceeds totaling approximately $0.5 million. In the first quarter of 2018, in connection with the Follow-On Offering of 3,592,858 shares of common stock, the offering included 14,286 shares sold to 1 officer, for aggregate proceeds totaling approximately $0.1 million and 71,429 shares sold to 1 investor who is an affiliate of 1 officer and board member, for proceeds totaling approximately $0.5 million.

Defined Contribution Plan	12 Months Ended
Defined Contribution Plan	Dec. 31, 2018
Defined Contribution Plan
Defined Contribution Plan	15. Defined Contribution Plan The Company adopted a 401(k) defined contribution plan on September 5, 2017, effective as of January 1, 2017, for all employees over age 21. Employees can defer up to 100% of their compensation through payroll withholdings into the plan subject to federal law limits. Effective January 1, 2018, the Company began matching contributions on deferrals at 100% of deferrals up to 3% of one’s contributions and 50% on deferrals over 3%, but not exceeding 5% of one’s contributions in order to satisfy certain non-discrimination tests required by the Internal Revenue Code. Employee contributions and any employer matching contributions made to satisfy certain non-discrimination tests required by the Internal Revenue Code are 100% vested upon contribution. Discretionary employer matches vest over a six-year period beginning on the second anniversary of an employee’s date of hire. The amount of matching contributions made during the years ended December 31, 2018 and 2017 was $0.1 million and zero, respectively.

Condensed Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Condensed Balance Sheets
Preferred stock, par value (in dollar per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollar per share)	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	14,265,411	10,633,042
Common stock, shares outstanding	14,265,411	10,633,042

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2018
Subsequent Events
Subsequent Events	16. Subsequent Events Term Loan Effective January 28, 2019, the Company prepaid in full all outstanding indebtedness under the Term Loan. As of the date of repayment, the Company had approximately $8.9 million in principal and interest outstanding as well as a final payment fee due of $1.0 million. Upon repayment, approximately $0.8 million of unamortized note discounts were recognized as interest expense. See Note 4 – Debt for further information relating to the Term Loan. A&R 2015 Plan Effective January 1, 2019, 501,001 shares were added to the A&R 2015 Plan under the share reserve provision. See Note 9 – Share-Based Compensation.

The Company and Basis of Presentation (Reverse Stock Split) (Details)	1 Months Ended
	Apr. 30, 2016
The Company and Basis of Presentation
Reverse stock split	0.320615582

The Company and Basis of Presentation (Going Concern) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
The Company and Basis of Presentation
Accumulated deficit	$ (84,111)	$ (60,474)
Cash and cash equivalents	$ 18,954	$ 18,473	$ 24,033	$ 3,620

Commitments and Contingencies - Pfizer License Agreement (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Commitments and Contingencies
No liabilities were recorded related to the license agreement	$ 11,920,000	$ 15,076,000
Pfizer, Inc. \| License Agreement
Commitments and Contingencies
No liabilities were recorded related to the license agreement	$ 0

Commitments and Contingencies - Other Agreements (Details) - USD ($)	1 Months Ended	12 Months Ended
	May 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Agreements
Agreement Term	3 years
Monthly base rent	$ 8,400
Lease term monthly base rate	$ 8,900
Future minimum lease payments of operating leases:
2019		$ 71,000
Total		71,000
Office Rental
Other Agreements
Rent expense		$ 100,000	$ 100,000	$ 58,000

Stockholders’ Equity (Deficit) - Warrants (Details)	12 Months Ended
Stockholders’ Equity (Deficit) - Warrants (Details)	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) shares	Jul. 31, 2018 $ / shares shares
Warrants
Purchase of additional common stock through warrants	993,204
Term of warrants	5 years
Exercise price of warrant \| $ / shares	$ 10.40
Fair market value of warrant \| $	$ 4,900,000
Exercise of warrants (in shares)		15,000
Exercise of warrants \| $	$ 0	$ 156,000
Warrants to purchase	1,014,204	978,204
Risk Free Interest Rate
Warrants
Warrant measurement	2.0		2.96
Expected Term
Warrants
Term of warrants	5 years		10 years
Expected Dividend Rate
Warrants
Warrant measurement	0		0
Price Volatility
Warrants
Warrant measurement	65.1		66
Term Loan \| SVB
Warrants
Purchase of additional common stock through warrants			36,000
Term of warrants			10 years
Exercise price of warrant \| $ / shares			$ 7.47

Stockholders’ Equity (Deficit) - Dividend Rights (Details)	12 Months Ended
	Dec. 31, 2018 USD ($) Vote / shares shares	Dec. 31, 2017 USD ($) shares
Voting Rights
Preferred stock, shares outstanding \| shares	0	0
Deferred offering costs	$ 0	$ 21,000
Common Stock
Dividends Rights
No dividends declared	$ 0
Voting Rights
Common stock, vote per share \| Vote / shares	1
Private placement
Voting Rights
Deferred offering costs		$ 21,000

Share-Based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
Share-Based Compensation (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	$ 4,131	$ 5,273	$ 1,718
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	2,378	4,091	1,166
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	$ 1,753	$ 1,182	$ 552

Share-Based Compensation - Assumptions (Details)	12 Months Ended
Share-Based Compensation - Assumptions (Details)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-Based Compensation
Expected stock price volatility	66.30%	65.80%	71.447%
Expected life of options (years)	5 years 9 months 18 days	5 years 10 months 24 days	6 years 7 days
Expected dividend yield	0.00%	0.00%	0.00%
Risk free interest rate	2.70%	2.00%	1.20%

Net Loss Per Common Share (Details) - USD ($)	12 Months Ended
Net Loss Per Common Share (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net Loss Per Common Share
Loss allocated to preferred stock	$ 0
Incremental common stock equivalents	0	0	0

Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Recurring
Fair value measurements
Total liabilities at Fair Value	$ 0	$ 0
Nonrecurring
Fair value measurements
Total liabilities at Fair Value	$ 0	$ 0

Fair Value Measurements - Roll-Forward of Premium conversion Derivative Liabilities (Details) - Premium conversion derivative $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)
Roll-forward of the company's premium conversion derivative liabilities
Balance as of beginning of period	$ 345
Issuance of underlying convertible notes	505
Change in fair value of premium conversion derivative	$ (850)

Income Taxes (Details) - USD ($)	12 Months Ended
Income Taxes (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
US Corporate income tax rate	21.00%	34.00%	34.00%
Effective tax rate	0.00%	0.00%	0.00%
Income tax benefit (expense)	$ 0
Maximum
US Corporate income tax rate		35.00%

Related Party Transactions - Rental agreement (Details) - Office Rental	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($) item	Dec. 31, 2016 USD ($) item	Dec. 31, 2015 USD ($) item
Other Agreements
Rent expense	$ 100,000	$ 100,000	$ 58,000
LLC owned by two officers
Other Agreements
Number of officers \| item		2	2	2
Rent expense	$ 0		$ 21,000	$ 23,000

Related Party Transactions - Interim Notes (Details)			1 Months Ended
Related Party Transactions - Interim Notes (Details)	Feb. 29, 2016 USD ($) item	Jul. 31, 2015 USD ($)	Apr. 30, 2016 USD ($) item	Feb. 29, 2016 USD ($) item	Dec. 31, 2015 USD ($)	Sep. 18, 2018 employee
Related Party Transaction [Line Items]
Number of employees \| employee						5
Interim Notes
Related Party Transaction [Line Items]
Proceeds from issuance of convertible notes \| $	$ 200,000	$ 2,800,000	$ 5,000,000	$ 200,000	$ 2,700,000
Debt Issued To Related Parties \| Interim Notes
Related Party Transaction [Line Items]
Proceeds from issuance of convertible notes \| $			5,000,000
Investor - 2 Board members \| Debt Issued To Related Parties \| Interim Notes
Related Party Transaction [Line Items]
Proceeds from issuance of convertible notes \| $				$ 81,000
Number of notes issued to related party \| item	2			2
Number of board members related to investors \| item	2			2
Investor related to an officer \| Debt Issued To Related Parties \| Interim Notes
Related Party Transaction [Line Items]
Proceeds from issuance of convertible notes \| $				$ 20,000
Investors related to 2 officers \| Debt Issued To Related Parties \| Interim Notes
Related Party Transaction [Line Items]
Proceeds from issuance of convertible notes \| $			$ 200,000
Number of notes issued to related party \| item			2
Number of officers \| item			2
Investors related to three directors \| Debt Issued To Related Parties \| Interim Notes
Related Party Transaction [Line Items]
Proceeds from issuance of convertible notes \| $			$ 2,300,000
Number of notes issued to related party \| item			3
Number of board members related to investors \| item			3

Defined Contribution Plan (Details) $ in Millions	12 Months Ended
Defined Contribution Plan (Details) $ in Millions	Dec. 31, 2018 USD ($) age	Dec. 31, 2017 USD ($)
Defined Contribution Plan Disclosure [Line Items]
Minimum age of employee to cover under the plan \| age	21
Employee compensation deferred percentage	100.00%
Employer match of employee contributions of eligible compensation	100.00%
Percentage of compensation matched by employer	3.00%
Employer match of over all employee contributions of eligible compensation	50.00%
Percentage of employee contribution vested on their contribution	100.00%
Employer matches vesting period	6 years
Amount of discretionary matching contributions on employee deferrals \| $	$ 0.1	$ 0.0
Maximum
Defined Contribution Plan Disclosure [Line Items]
Percentage of compensation matched by employer	5.00%

Subsequent Events (Details) - USD ($) $ in Thousands		1 Months Ended
Subsequent Events (Details) - USD ($) $ in Thousands	Jan. 28, 2019	Jul. 31, 2017	Jan. 01, 2019	Dec. 31, 2018	Dec. 31, 2017
Subsequent Events
Term loan					$ 8,683
A&R 2015 Plan
Subsequent Events
Common stock reserved for issuance (in shares)				415,077	0
A&R 2015 Plan \| Subsequent Event
Subsequent Events
Common stock reserved for issuance (in shares)			501,001
Term Loan
Subsequent Events
Debt discount amortized as interest expenses		$ 100
Term Loan \| Subsequent Event
Subsequent Events
Term loan	$ 8,900
Debt discount amortized as interest expenses	800
SVB \| Term Loan \| Subsequent Event
Subsequent Events
Payment fee due	$ 1,000