0001047469-20-001338 | 10-K | XBRL Viewer | Catabasis Pharmaceuticals INC

Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2019	Mar. 02, 2020	Jun. 30, 2019
Document and Entity Information
Entity Registrant Name	CATABASIS PHARMACEUTICALS INC
Document Type	10-K
Document Period End Date	Dec. 31, 2019
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		17,897,172
Entity Public Float			$ 73,359,556
Entity Central Index Key	0001454789
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 9,899	$ 15,294
Short-term investments	26,345	22,276
Prepaid expenses and other current assets	2,714	1,345
Total current assets	38,958	38,915
Right-of-use asset	2,349
Other assets	473	254
Total assets	41,780	39,169
Current liabilities:
Accounts payable	1,197	1,408
Accrued expenses	2,610	2,763
Current portion of operating lease liabilities	1,225
Total current liabilities	5,032	4,171
Other long-term liabilities		56
Long-term portion of operating lease liabilities	1,028
Total liabilities	6,060	4,227
Commitments (Note 6)
Stockholders' equity:
Preferred stock, $0.001 par value per share, 5,000,000 shares authorized and no shares issued and outstanding
Common stock, $0.001 par value per share, 150,000,000 shares authorized; 12,433,600 and 7,141,996 shares issued and outstanding at December 31, 2019 and December 31, 2018, respectively	12	7
Additional paid-in capital	259,305	232,243
Accumulated other comprehensive loss		(4)
Accumulated deficit	(223,597)	(197,304)
Total stockholders' equity	35,720	34,942
Total liabilities and stockholders' equity	$ 41,780	$ 39,169

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Consolidated Balance Sheets
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, authorized (in shares)	5,000,000	5,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	150,000,000	150,000,000
Common stock, issued (in shares)	12,433,600	7,141,996
Common stock, outstanding (in shares)	12,433,600	7,141,996

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating expenses:
Research and development	$ 18,317	$ 17,042
General and administrative	8,771	9,329
Total operating expenses	27,088	26,371
Loss from operations	(27,088)	(26,371)
Other income (expense):
Interest expense		(100)
Interest and investment income	845	425
Other (expense) income, net	(50)	176
Total other income, net	795	501
Net loss	$ (26,293)	$ (25,870)
Net loss per share - basic and diluted (in dollars per share)	$ (2.35)	$ (5.12)
Weighted-average common shares outstanding used in net loss per share - basic and diluted (in shares)	11,199,057	5,054,823

Consolidated Statements Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Consolidated Statements Comprehensive Loss
Net loss	$ (26,293)	$ (25,870)
Other comprehensive income:
Gains (losses) on short-term investments	4	(4)
Total other comprehensive (loss) income:	4	(4)
Comprehensive loss	$ (26,289)	$ (25,874)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common stock	Additional paid-in capital	Accumulated deficit	Accumulated other comprehensive loss	Total
Balance at Dec. 31, 2017	$ 2	$ 183,224	$ (171,434)		$ 11,792
Balance (in shares) at Dec. 31, 2017	2,364,526
Increase (Decrease) in Shareholders' Equity
Issuance of common stock and warrants in public offering, net of issuance costs	$ 4	38,882			38,886
Issuance of common stock and warrants in public offering, net of issuance costs (in shares)	4,200,000
Issuance of common stock for at-the-market offerings	$ 1	8,362			8,363
Issuance of common stock for at-the-market offerings (in shares)	577,195
Proceeds from exercises of common stock options		4			4
Proceeds from exercises of common stock options (in shares)	291
Stock-based compensation expense		1,771			1,771
Fractional shares eliminated pursuant to reverse stock split	(16)
Unrealized losses on short-term investments				$ (4)	(4)
Net loss			(25,870)		(25,870)
Balance at Dec. 31, 2018	$ 7	232,243	(197,304)	(4)	$ 34,942
Balance (in shares) at Dec. 31, 2018	7,141,996				7,141,996
Increase (Decrease) in Shareholders' Equity
Issuance of common stock and warrants in public offering, net of issuance costs	$ 4	18,501			$ 18,505
Issuance of common stock and warrants in public offering, net of issuance costs (in shares)	4,000,000
Issuance of common stock for at-the-market offerings	$ 1	6,995			6,996
Issuance of common stock for at-the-market offerings (in shares)	1,282,904
Proceeds from exercises of common stock options		54			$ 54
Proceeds from exercises of common stock options (in shares)	8,700				0
Stock-based compensation expense		1,512			$ 1,512
Unrealized losses on short-term investments				$ 4	4
Net loss			(26,293)		(26,293)
Balance at Dec. 31, 2019	$ 12	$ 259,305	$ (223,597)		$ 35,720
Balance (in shares) at Dec. 31, 2019	12,433,600				12,433,600

Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Initial public offering
Stock issuance costs	$ 0.4	$ 0.4
Common stock warrants
Stock issuance costs	$ 1.5	$ 3.1

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Operating activities
Net loss	$ (26,293)	$ (25,870)
Reconciliation of net loss to net cash used in operating activities:
Depreciation and amortization	26	119
Stock-based compensation expense	1,512	1,771
Accretion of discount/premium on investment securities	5	(6)
Non-cash interest expense		37
Gain on disposal of property and equipment	18	(297)
Services received in non-monetary exchange	33	19
Changes in assets and liabilities:
Prepaid expenses and other current assets	(1,289)	(177)
Other assets		(85)
Right-of-use asset-operating	(96)
Accounts payable	(211)	662
Accrued expenses	(205)	396
Other liabilities	(69)	(34)
Net cash used in operating activities	(26,569)	(23,465)
Investing activities
Purchases of short-term investments	(155,197)	(70,364)
Sales and maturities of short-term investments	151,127	48,090
Purchases of property and equipment	(12)
Proceeds from sale of property and equipment		369
Net cash used in investing activities	(4,082)	(21,905)
Financing activities
Proceeds from public offerings, net of issuance costs	18,505	38,886
Proceeds from at-the-market offering, net of issuance costs	7,061	8,253
Proceeds from exercise of common stock options and warrants	54	4
Payments on borrowing		(2,848)
Net cash provided by financing activities	25,620	44,295
Net increase in cash, cash equivalents and restricted cash	(5,031)	(1,075)
Cash, cash equivalents and restricted cash, beginning of period	15,407	16,482
Cash, cash equivalents and restricted cash, end of period	10,376	15,407
Supplemental disclosure of cash flow information
Cash paid for interest		79
Non-cash investing activities:
Fixed asset purchases included in accounts payable		18
Non-cash financing activities
At-the-market issuance costs included in current liabilities	$ 65	$ 110

Organization and Operations	12 Months Ended
Organization and Operations	Dec. 31, 2019
Organization and Operations
Organization and Operations	1. Organization and Operations The Company Catabasis Pharmaceuticals, Inc. (the "Company") is a clinical-stage biopharmaceutical company. The Company’s lead program is edasalonexent, an oral small molecule designed to inhibit NF-B, or nuclear factor kappa-light-chain-enhancer of activated B cells, in development for the treatment of Duchenne muscular dystrophy (“DMD”). The Company believes edasalonexent has the potential to be a foundational therapy for all patients affected by DMD, regardless of the underlying dystrophin mutation. DMD is an ultimately fatal genetic disorder involving progressive muscle degeneration. The United States Food and Drug Administration has granted orphan drug, fast track and rare pediatric disease designations to edasalonexent for the treatment of DMD. The European Commission has granted orphan medicinal product designation to edasalonexent for the treatment of DMD. The Company was incorporated in the State of Delaware on June 26, 2008. Liquidity The Company has entered into various sales agreements with Cowen and Company LLC, (“Cowen”), pursuant to which the Company could issue and sell shares of common stock under at-the-market offering programs (the “ATM Programs”). Shares sold pursuant to these sales agreements were sold pursuant to shelf registration statements, one of which became effective on July 19, 2016 and which was replaced by a new shelf registration statement, which became effective May 22, 2019. The Company pays Cowen 3% of the gross proceeds from any common stock sold through these sales agreements. The Company currently has $43.6 million remaining available under its sales agreement. During the year ended December 31, 2019, the Company sold an aggregate of 1,282,904 shares of common stock pursuant to the ATM Programs, at an average price of $5.81 per share, for gross proceeds of $7.5 million, resulting in net proceeds of $7.0 million after deducting sales commissions and offering expenses. On February 6, 2019, the Company entered into an underwriting agreement with Oppenheimer & Co. Inc. relating to an underwritten public offering (the “February 2019 Financing”) of 4,000,000 shares of common stock and accompanying warrants to purchase up to 2,000,000 shares of common stock, at a combined price to the public of $5.00 per unit, for net proceeds of $18.5 million. On June 19, 2018, the Company entered into an underwriting agreement with Oppenheimer & Co. Inc. relating to an underwritten public offering (the “June 2018 Financing”) of 4,200,000 shares of the Company’s common stock, par value $0.001 per share, and accompanying warrants to purchase up to 4,200,000 shares of common stock, at a combined price to the public of $10.00 per unit, for gross proceeds of $42.0 million, and net proceeds of $38.9 million. As of December 31, 2019, the Company had an accumulated deficit of $223.6 million. The Company has been primarily involved with research and development activities and has incurred operating losses and negative cash flows from operations since its inception. The Company is subject to a number of risks similar to other life science companies, including, but not limited to, successful discovery and development of its drug candidates, raising additional capital, development by its competitors of new technological innovations, protection of proprietary technology and regulatory approval and market acceptance of the Company’s products. The Company anticipates that it will continue to incur significant operating losses for the next several years as it continues to develop its product candidates. As of December 31, 2019, the Company had available cash, cash equivalents and short-term investments of $36.2 million. Subsequent to December 31, 2019, the Company raised net proceeds of $25.6 million through 2020 equity financings. Based on the Company’s current operating plan, the Company believes it has sufficient cash, cash equivalents and short-term investments to fund operations for at least 12 months following the issuance of these consolidated financial statements. The Company will require substantial additional capital to fund operations. The Company has not generated any product revenues and has financed its operations primarily through public offerings and private placements of its equity securities. There can be no assurance that the Company will be able to obtain additional debt or equity financing or generate product revenue or revenues from collaborative partners, on terms acceptable to the Company, on a timely basis or at all. The failure of the Company to obtain sufficient funds on acceptable terms when needed could have a material adverse effect on the Company’s business, results of operations, and financial condition.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2019

Summary of Significant Accounting Policies

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation and Principles of Consolidation

The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary, Catabasis Securities Corporation. All intercompany balances and transactions have been eliminated in consolidation. These consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) and include all adjustments necessary for the fair presentation of the Company’s financial position for the periods presented.

Use of Estimates

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

The Company utilizes certain estimates to record expenses relating to research and development contracts. These contract estimates, which are primarily related to the length of service of each contract and the amount of service provided as of each measurement date, are determined by the Company based on input from internal project management, as well as from third-party service providers.

Off-Balance Sheet Risk and Concentrations of Credit Risk

The Company has no off-balance sheet risk, such as foreign exchange contracts, option contracts or other foreign hedging arrangements. Financial instruments that subject the Company to credit risk primarily consist of cash, cash equivalents, short-term investments and restricted cash. The primary objectives for the Company's investment portfolio are the preservation of capital and the maintenance of liquidity. The Company's investment policy includes guidelines on the quality of the institutions and financial instruments and defines allowable investments that the Company believes minimizes the exposure to concentration of credit risk.

Cash and Cash Equivalents and Restricted Cash

The Company considers highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash equivalents, which consist of money market funds, corporate debt securities and reverse repurchase agreements are stated at fair value. Cash and cash equivalents consist of the following (in thousands):


	December 31,
	2019		2018
Cash	$	2,530	$	4,390
Money market fund		5,432		5,956
Corporate debt securities		1,937		1,948
Reverse repurchase agreements		—		3,000
Total	$	9,899	$	15,294

The reconciliation of cash, cash equivalents and restricted cash reported within the applicable balance sheet that sum to the total of the same such amount shown in the statement of cash flows is as follows:


	December 31,
	2019		2018
Cash and cash equivalents	$	9,899	$	15,294
Restricted cash (1)		477		113
Total	$	10,376	$	15,407

(1) Included in prepaid expenses and other current assets and other assets as of December 31, 2019 and other assets as of December 31, 2018 in the consolidated balance sheets

Short-Term Investments

The Company classifies all corporate debt securities with a remaining maturity of greater than three months and reverse repurchase agreements with a remaining maturity of greater than one business day at the time of purchase as short-term investments. Short-term investments are recorded at fair value, with the unrealized gains and losses reported in other comprehensive loss. The amortized cost of debt securities is adjusted for the amortization of premiums and accretion of discounts to maturity. Such amortization is included in interest and investment income. Realized gains and losses, interest, dividends and declines in value judged to be other-than-temporary are included in interest and investment income.

The cost of securities sold is based on the specific identification method for purposes of recording realized gains and losses. To determine whether an other-than-temporary impairment exists, the Company considers whether it has the ability and intent to hold the investment until a market price recovery, and whether evidence indicating the recoverability of the cost of the investment outweighs evidence to the contrary.

Fair Value of Financial Instruments

The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three broad levels as follows: Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities; Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly; and Level 3 inputs are unobservable inputs that reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement.

The carrying amounts reflected in the balance sheets for cash equivalents, restricted cash, prepaid expenses and other current assets, accounts payable and accrued expenses approximate their fair values at December 31, 2019 and 2018, due to their short-term nature. There have been no changes to the valuation methods during the years ended December 31, 2019 and 2018. The Company evaluates transfers between levels at the end of each reporting period. There were no transfers of assets or liabilities between levels during the year ended December 31, 2019 and 2018.

The Company’s investment portfolio may include fixed income securities that do not always trade on a daily basis. As a result, the pricing services used by the Company apply other available information as applicable through processes such as benchmark yields, benchmarking of like securities, sector groupings and matrix pricing to prepare valuations. The Company validates the prices provided by its third party pricing services by obtaining market values from other pricing sources and analyzing pricing data in certain instances. The Company also invests in certain reverse repurchase agreements which are collateralized by deposits in the form of U.S. Government Securities and Obligations for an amount no less than 102% of their value. The Company does not record an asset or liability for the collateral as the Company is not permitted to sell or re-pledge the collateral. The collateral has at least the prevailing credit rating of U.S. Government Treasuries and Agencies. The Company utilizes a third party custodian to manage the exchange of funds and ensure that collateral received is maintained at 102% of the value of the reverse repurchase agreements on a daily basis.

Impairment of Long-Lived Assets

The Company continually evaluates whether events or circumstances have occurred that indicate that the estimated remaining useful life of its long-lived assets may warrant revision or that the carrying value of these assets may be impaired. The Company has not recognized any significant impairment charges from inception through December 31, 2019.

Research and Development Expenses

Research and development costs are expensed as incurred. Research and development costs include salaries and personnel-related costs, stock-based compensation, consulting fees, fees paid for contract research services, the costs of laboratory equipment and facilities and other external costs. Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are deferred. The deferred amounts are expensed as the related goods are delivered or the services are performed.

Stock-Based Compensation

The Company accounts for its stock-based compensation awards in accordance with Accounting Standards Codification (“ASC”) Topic 718, Compensation—Stock Compensation (“ASC 718”). ASC 718 requires all share-based payments to employees, including grants of employee stock options, to be recognized in the statements of operations based on their grant date fair values. For granted stock options, the Company estimates the grant date fair value of each option award using the Black-Scholes option-pricing model. The use of the Black-Scholes option-pricing model requires management to make assumptions with respect to the expected term of the option, the expected volatility of the Common Stock consistent with the expected term of the option, risk-free interest rates and expected dividend yields of the Common Stock.

For awards subject to service-based vesting conditions, the Company recognizes stock-based compensation expense equal to the grant date fair value of stock options on a straight-line basis over the requisite service period.

The Company expenses restricted stock awards based on the fair value of the award on a straight-line basis over the associated service period of the award.

During the years ended December 31, 2019 and 2018, the Company recorded stock-based compensation expense for employee and non-employee stock options and restricted stock, which was allocated as follows in the statements of operations (in thousands):


	Year Ended December 31,
	2019		2018
Research and development	$	616	$	673
General and administrative		896		1,098
Total	$	1,512	$	1,771

No related tax benefits were recognized for the years ended December 31, 2019 and 2018.

Net Loss Per Share

Basic net loss per share is calculated by dividing net loss by the weighted average shares outstanding during the period, without consideration for Common Stock equivalents. Diluted net loss per share is calculated by adjusting weighted average shares outstanding for the dilutive effect of Common Stock equivalents outstanding for the period, determined using the treasury-stock method. For purposes of the Company’s dilutive net loss per share calculation, stock options and warrants to purchase Common Stock were considered to be Common Stock equivalents but were excluded from the calculation of diluted net loss per share, as their effect would be anti-dilutive; therefore, basic and diluted net loss per share were the same for all periods presented.

The following Common Stock equivalents were excluded from the calculation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect:


	Year Ended December 31,
	2019	2018
Stock options	785,832	433,389
Common stock warrants	6,193,749	4,202,449
	6,979,581	4,635,838

Income Taxes

The Company provides deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the Company's financial statement carrying amounts and the tax basis of assets and liabilities using enacted tax rates expected to be in effect in the years in which the differences are expected to reverse. A valuation allowance is provided to reduce the deferred tax assets to the amount that will more likely than not be realized.

The Company accounts for uncertain tax positions in accordance with the provisions of ASC Topic 740, Expenses—Income Taxes. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company did not have any significant uncertain tax positions for any periods presented.

Segment Information

Operating segments are identified as components of an enterprise for which separate discrete financial information is available for evaluation by the chief operating decision maker, or decision making group, in making decisions on how to allocate resources and assess performance. The Company views its operations and manages its business in one operating segment. The Company operates in one geographic segment.

Comprehensive Loss

Comprehensive loss is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. For the years ended December 31, 2019 and 2018 amounts in accumulated other comprehensive loss were comprised of unrealized gains and losses on short-term investments.

Leases

Effective January 1, 2019, the Company determines if an arrangement is a lease at inception. Operating leases are included in right-of-use ("ROU") lease assets, current portion of lease obligations, and long-term lease obligations on the Company's balance sheets. The Company does not currently hold any financing leases.

ROU lease assets represent the Company's right to use an underlying asset for the lease term and lease obligations represent the Company's obligation to make lease payments arising from the lease. Operating ROU lease assets and obligations are recognized at the commencement date based on the present value of lease payments over the lease term. As the Company's facility leases do not provide an implicit rate, the Company uses its estimated incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The Company's ROU lease assets also include any lease payments made and excludes lease incentives. If the Company's facility lease includes options to terminate the lease which would affect the lease period when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments under facility leases are recognized on a straight-line basis over the lease term.

Recent Accounting Pronouncements—Adopted

In February 2016, the Financial Accounting Standards Board, (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, Leases. This standard amends the existing guidance to require lessees to present most leases on their balance sheets and recognize corresponding expenses on their statements of operations. The FASB also provided practical expedients that give lessors an option to combine non-lease and associated lease components when certain criteria are met and requires a lessor to account for the combined component in accordance with the new revenue standard if the associated non-lease components are the predominant component. The Company adopted this standard effective January 1, 2019 by recording the cumulative effect on the date of the adoption. The Company has elected the package of practical expedients permitted under the transition guidance in ASC Topic 842, Leases, (“ASC Topic 842”). Accordingly, the Company accounted for its existing operating leases as operating leases under the new guidance, without reassessing (a) whether the contracts contain a lease under ASC Topic 842, (b) whether classification of the operating leases would be different in accordance with ASC Topic 842, or (c) whether the unamortized initial direct costs before transition adjustments would have met the definition of initial direct costs in ASC Topic 842 at lease commencement. As a result of the adoption of the new lease accounting guidance, the Company recognized on January 1, 2019 a lease liability and right-of-use asset of approximately $1.9 million. The lease liability represents the present value of the remaining lease payments, discounted using the Company’s estimated incremental borrowing rate of 7.49%. The ROU asset represents the lease liability adjusted for any prepaid and accrued rent payments as well as any remaining liability associated with an active sublease. This standard did not have a material impact on the Company’s cash flows from operations and had no impact on the Company’s operating results. The most significant impact was the recognition of ROU assets and lease obligations for operating leases.

Recent Accounting Pronouncements—Not Yet Adopted

From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326). This standard requires a financial asset to be presented at amortized cost basis at the net amount expected to be collected. It also requires that credit losses relating to available-for-sale debt securities should be recorded through an allowance for credit losses. In November 2019, the FASB issued an amendment making this ASU effective for annual reporting periods beginning after December 15, 2022 for smaller reporting companies. The Company is currently evaluating the impact that this standard will have on its consolidated financial statements.

In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820). This standard includes amendments regarding changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and disclosure requirements of measurement uncertainty. This amendment is effective for annual reporting periods beginning after December 15, 2019. The Company is currently evaluating the impact that this standard will have on its consolidated financial statements.

Financial Instruments

12 Months Ended

Dec. 31, 2019

Financial Instruments

Financial Instruments

3. Financial Instruments

The following tables present information about the Company’s financial assets and liabilities that have been measured at fair value, and indicates the fair value hierarchy of the valuation inputs utilized to determine such fair value. Below is a summary of assets and liabilities measured at fair value on a recurring basis (in thousands):


	As of December 31, 2019
	Quoted Prices		Significant		Significant
	in Active		Observable		Unobservable
	Markets		Inputs		Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets:
Cash and cash equivalents:
Money market funds	$	5,432	$	—	$	—	$	5,432
Corporate debt securities		—		1,937		—		1,937
Short-term investments:
Commercial paper		—		1,993		—		1,993
Corporate debt securities		—		3,352		—		3,352
Reverse repurchase agreements		—		21,000		—		21,000
Total assets	$	5,432	$	28,282	$	—	$	33,714


	As of December 31, 2018
	Quoted Prices		Significant		Significant
	in Active		Observable		Unobservable
	Markets		Inputs		Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets:
Cash and cash equivalents:
Money market funds	$	5,956	$	—	$	—	$	5,956
Corporate debt securities		—		1,948		—		1,948
Reverse repurchase agreements		—		3,000		—		3,000
Short-term investments:
Corporate debt securities		—		7,276		—		7,276
Reverse repurchase agreements		—		15,000		—		15,000
Total assets	$	5,956	$	27,224	$	—	$	33,180

- 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

Short-Term Investments

12 Months Ended

Dec. 31, 2019

Short-Term Investments

Short-Term Investments

4. Short-Term Investments

The following table summarizes the short-term investments held at December 31, 2019 and 2018 (in thousands):


			Gross Unrealized		Gross Unrealized
	Amortized Cost		Gains		Losses		Fair Value
December 31, 2019
Commercial paper	$	1,993	$	—	$	—	$	1,993
Corporate debt securities		3,352		—		—		3,352
Reverse repurchase agreements		21,000		—		—		21,000
Total	$	26,345	$	—	$	—	$	26,345


			Gross Unrealized		Gross Unrealized
	Amortized Cost		Gains		Losses		Fair Value
December 31, 2018
Corporate debt securities	$	7,280	$	—	$	(4)	$	7,276
Reverse repurchase agreements		15,000		—		—		15,000
Total	$	22,280	$	—	$	(4)	$	22,276

The contractual maturities of all short-term investments held at December 31, 2019 and 2018 were one year or less. There were four short-term investments in an unrealized loss position at December 31, 2019, none of which had been in an unrealized loss position for more than 12 months. The aggregate fair value of these securities at December 31, 2019 was approximately $3.4 million. There were seven short-term investments in an unrealized loss position at December 31, 2018, none of which had been in an unrealized loss position for more than 12 months. The aggregate fair value of these securities at December 31, 2018 was approximately $7.3 million. The Company did not hold any securities with other-than-temporary impairments at December 31, 2019 and 2018.

Gross realized gains and losses on the sales of short-term investments are included in other income, net. Unrealized holding gains or losses for the period that have been included in accumulated other comprehensive income, as well as gains and losses reclassified out of accumulated other comprehensive income into other income, net were not material to the Company’s consolidated results of operations. During the years ended December 31, 2019 and 2018 all proceeds related to maturities of underlying securities. The gains on proceeds of maturities of short-term investments were not material to the Company’s consolidated results of operations for the years ended December 31, 2019 and 2018.

Restricted Cash	12 Months Ended
Restricted Cash	Dec. 31, 2019
Restricted Cash
Restricted Cash	5. Restricted Cash At December 31, 2019 the Company had two outstanding letters of credit for a total of approximately $0.5 million as security deposits for its operating lease agreements for office space (Note 7). The Company is required to maintain these deposits for the duration of the lease agreements.

Accrued Expenses

12 Months Ended

Dec. 31, 2019

Accrued Expenses

Accrued Expenses

6. Accrued Expenses

Accrued expenses consisted of the following (in thousands):


	December 31,
	2019		2018
Accrued compensation	$	1,365	$	1,241
Accrued contracted research costs		737		680
Accrued professional fees		370		393
Accrued other		98		109
Accrued franchise tax		40		168
Accrued severance		—		172
Total	$	2,610	$	2,763

Commitments

12 Months Ended

Dec. 31, 2019

Commitments

Commitments

7. Commitments

In November 2010, the Company entered into an operating lease for office and laboratory space, which has been amended multiple times. Based on the latest amendment, the lease agreement includes escalating rent payments and is effective through June 30, 2020.

On October 15, 2018, the Company entered into a short-term lease with Inzen Therapeutics ("Inzen"), to sublease a portion of the Company's facility (the "Sublease"). The sublease term is from October 15, 2018 through June 30, 2020. Inzen is obligated to pay the Company approximately $0.5 million in base rent during the year ended December 31, 2020, respectively. The Company is still obligated to all payment terms pursuant to the lease agreement, as amended. During the years ended December 31, 2019 and 2018, the Company received $1.0 million and $0.3 million in payments from Inzen which was recorded as a reduction to rent expense in the accompanying consolidated statement of operations.

In November 2019, the Company entered into a sublease for office space which was classified as an operating lease. At inception of the lease, the Company recognized a lease liability and right-of-use asset of approximately $1.7 million. The lease liability represents the present value of the remaining lease payments, discounted using the Company’s estimated incremental borrowing rate of 7.49%. The ROU asset represents the lease liability adjusted for any prepaid and accrued rent payments.

Future minimum payments required under the non-cancelable operating leases as of December 31, 2019 are summarized as follows (in thousands):


Period Ending December 31,	Amount
2020		1,449
2021		740
2022		438
Total minimum lease payments	$	2,627

Rent expense was $0.4 million and $1.1 million for the years ended December 31, 2019 and 2018, respectively. Lease payments were $1.4 million for each of the years ended December 31, 2019 and 2018, respectively.

Stockholders' Equity

12 Months Ended

Dec. 31, 2019

Stockholders' Equity

Stockholders' Equity

8. Stockholders’ Equity

Preferred Stock

As of December 31, 2019, the Company had 5,000,000 shares of preferred stock authorized for issuance, $0.001 par value per share, with none issued or outstanding. Preferred stock may be issued from time to time in one or more series, each series to have such terms as stated or expressed in the resolutions providing for the issue of such series adopted by the board of directors of the Company. Preferred stock which may be redeemed, purchased or acquired by the Company may be reissued except as otherwise provided by law.

Common Stock Warrants

February 2019 Warrants

In the February 2019 Financing, the Company issued warrants to purchase 2,000,000 shares of common stock with an exercise price of $6.25 per share, which were immediately exercisable upon issuance and will expire five years from the date of issuance.

The terms of the warrants include certain provisions related to fundamental transactions, a cashless exercise provision in the event registered shares are not available, and do not include any mandatory redemption provisions. Therefore, the warrants have been classified in stockholders’ equity. Any changes to the fair value of the warrants will not be recognized so long as the warrants continue to be equity classified.

As of December 31, 2019, warrants to purchase 1,991,300 shares that were issued in the February 2019 Financing were outstanding with a remaining contractual life of 4.11 years.

June 2018 Warrants

In the June 2018 Financing, the Company issued warrants to purchase 4,200,000 shares of common stock with an exercise price of $12.00 per share, which were immediately exercisable upon issuance and will expire five years from the date of issuance.

The terms of the warrants include certain provisions related to fundamental transactions, a cashless exercise provision in the event registered shares are not available and do not include any mandatory redemption provisions. Therefore, the warrants have been classified in stockholders’ equity. Any changes to fair value of the warrants will not be recognized so long as the warrants continue to be equity classified.

As of December 31, 2019, all warrants related to this transaction were outstanding with a remaining contractual life of 3.47 years.

Common Stock

As of December 31, 2019, the Company had 150,000,000 shares of Common Stock authorized for issuance, $0.001 par value per share, with 12,433,600 shares issued and outstanding. The voting, dividend and liquidation rights of holders of Common Stock are subject to and qualified by the rights, powers and preferences of the holders of any outstanding Preferred Stock. The Company's Common Stock has the following characteristics:

Voting

The holders of Common Stock are entitled to one vote for each share of Common Stock held at all meetings of stockholders and written actions in lieu of meetings.

Dividends

The holders of Common Stock are entitled to receive dividends, if and when declared by the board of directors. Cash dividends may not be declared or paid to holders of Common Stock until paid on each series of outstanding Preferred Stock in accordance with their respective terms. No dividends have been declared or paid from the Company's inception through December 31, 2019.

Liquidation

In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company, the holders of Common Stock are entitled to share ratably in the Company’s assets available for distribution to stockholders, subject to any preferential or other rights of any then-outstanding Preferred Stock.

Reserved for Future Issuance

The Company has reserved for future issuance the following shares of Common Stock:


	December 31,
	2019	2018
Warrants for the purchase of Common Stock	6,193,749	4,202,449
Options outstanding to purchase Common Stock	785,832	433,389
Options available for future issuance to purchase Common Stock	525,484	877,917
Shares reserved for the employee stock purchase plan	112,481	76,011
Total	7,617,546	5,589,766

Stock Incentive Plans

12 Months Ended

Dec. 31, 2019

Stock Incentive Plans

Stock Incentive Plans

9. Stock Incentive Plans

Prior to the Company’s initial public offering in June 2015 (the “IPO”), the Company granted awards to eligible participants under its 2008 Equity Incentive Plan. In May 2015, the Company’s board of directors adopted and, in June 2015, the Company’s stockholders approved the 2015 Stock Incentive Plan (“2015 Plan”), which became effective immediately prior to the effectiveness of the IPO. Subsequent to the IPO, option grants are awarded to eligible participants only under the 2015 Plan.

The 2015 Plan provides for the grant of incentive stock options, non-statutory stock options, restricted stock awards, restricted stock units, stock appreciation rights and other stock-based awards. The Company’s employees, officers, directors and consultants and advisors are eligible to receive awards under the 2015 Plan.

Terms of stock option agreements, including vesting requirements, are determined by the Company's board of directors, subject to the provisions of the applicable stock incentive plan. Options granted by the Company generally vest ratably over four years, with a one-year cliff, and options are exercisable from the date of grant for a period of ten years. For options granted through December 31, 2019, the exercise price or purchase price, as applicable, equaled the estimated fair value of the Common Stock as determined by the Company's board of directors on the date of grant.

A summary of the Company’s stock option activity and related information for employees and non-employees follows:


				Weighted
				Average
		Weighted-		Remaining	Aggregate
		Average Exercise		Contractual	Intrinsic Value
	Shares	Price		Term (years)	(in thousands)
Outstanding at December 31, 2018	433,389	$	29.05	7.97	$	—
Granted	454,420	$	4.86
Cancelled or forfeited	(101,977)	$	18.12
Outstanding at December 31, 2019	785,832	$	16.48	8.13	$	470
Vested and Exercisable at December 31, 2019	289,782	$	33.91	6.59	$	9

There were no options exercised in the year ended December 31, 2019. The total intrinsic value of options exercised in the year ended December 31, 2018 was $1 thousand. The total fair value of employee options vested for the years ended December 31, 2019 and 2018 was $1.5 million and $1.7 million, respectively. The weighted-average grant date fair value of options granted to employees and non-employees for the years ended December 31, 2019 and 2018 was $3.25 and $6.64, respectively.

At December 31, 2019, the total unrecognized compensation expense related to unvested stock option awards was $1.7 million. The Company expects to recognize that cost over a weighted-average period of approximately 2.2 years.

Stock-Based Compensation Expense

The fair value of stock options granted to employees and non-employees was estimated using the Black-Scholes option-pricing model based on the following assumptions:


	Year Ended December 31,
	2019				2018
Weighted-average expected volatility	68.9	-	110.5	%	73.7	-	76.9	%
Expected term (in years)	5.50	-	10.00		5.75	-	6.25
Risk-free interest rate	1.39	-	2.69	%	2.67	-	2.84	%
Expected dividend yield			0	%			0	%

Volatility

Due to the lack of company-specific historical and implied volatility data of its Common Stock, the Company does not have relevant historical data to support its expected volatility. As such, the Company has used a weighted average of expected volatility based on the volatilities of a representative group of publicly traded biopharmaceutical companies. For purposes of identifying representative companies, the Company considered characteristics such as number of product candidates in early stages of product development, area of therapeutic focus, and length of trading history. The expected volatility was determined using an average of the historical volatilities of the representative group of companies for a period equal to the expected term of the option grant. The Company intends to continue to consistently apply this process using the same representative companies until a sufficient amount of historical information regarding the volatility of the Company's own share price becomes available or until circumstances change, such that the identified entities are no longer representative companies. In the latter case, more suitable, similar entities whose share prices are publicly available would be utilized in the calculation.

Expected Term

The Company uses the “simplified method” to estimate the expected term of stock option grants. Under this approach, the weighted-average expected life is presumed to be the average of the contractual term (ten years) and the vesting term (generally four years) of the Company's stock options, taking into consideration multiple vesting tranches. The Company utilizes this method due to lack of historical exercise data and the plain-vanilla nature of the Company's share-based awards.

Risk-Free Rate

The risk-free rate was based on the yield curve of U.S. Treasury securities with periods commensurate with the expected term of the options being valued.

Income Taxes

12 Months Ended

Dec. 31, 2019

Income Taxes

Income Taxes

10. Income Taxes

For the years ended December 31, 2019 and 2018, the Company did not record a provision for federal or state income taxes as it has incurred cumulative net operating losses since inception.

A reconciliation of the U.S. statutory income tax rate to the Company's effective tax rate is as follows for the years ended December 31, 2019 and 2018:


	Year Ended December 31,
	2019		2018
Federal income tax (benefit) at statutory rate	21.00	%	21.00	%
Permanent differences	(0.57)		(0.68)
Federal research and development credits and adjustments	2.42		4.25
State income tax, net of federal benefit	5.50		6.84
Other	0.49		(1.41)
Change in valuation allowance	(28.85)		(30.00)
Effective income tax rate	—	%	—	%

The Company's deferred tax assets consisted of the following (in thousands):


	Year Ended December 31,
	2019		2018
Deferred tax assets
Net operating loss carryforwards	$	55,283	$	48,107
Tax credit carryforwards		8,030		7,174
Capitalized research and development		922		1,394
Capitalized legal expenses		1,073		1,132
Lease liability		639		—
Other differences		1,453		1,370
Total deferred tax assets		67,400		59,177
Deferred tax liabilities
ROU asset		(639)		—
Valuation allowance		(66,761)		(59,177)
Net deferred tax assets	$	—	$	—

The Company recorded an increase to the valuation allowance of $7.6 million during the year ended December 31, 2019 due primarily to the federal and state net operating losses and tax credits generated.The Company recorded an increase to the valuation allowance of $7.8 million during the year ended December 31, 2018 which was also primarily due to the federal and state net operating losses and tax credits generated.

In assessing the realizability of deferred tax assets, the Company considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which the temporary differences representing net future deductible amounts become deductible. Due to the Company's history of losses and expectation of future losses, the deferred tax assets were fully offset by a valuation allowance at December 31, 2019 and 2018.

As of December 31, 2019, the Company had approximately $203.0 million of federal and $200.2 million of state net operating loss respectively, which may be available to offset future taxable income. Federal net operating loss carryforwards of $150.5 million and state net operating loss carryforwards of $200.2 million will expire at various dates from 2023 through 2039. Federal net operating loss carryforwards of $52.5 million can be carried forward indefinitely. The Company had approximately $6.3 million of federal and $2.2 million of state tax credit carryforwards available to reduce future tax liabilities as of December 31, 2019, which will expire at varying times through the year 2039.

The Internal Revenue Code of 1986, as amended (the “Code”), provides for a limitation of the annual use of net operating losses and other tax attributes (such as research and development tax credit carryforwards) following certain ownership changes (as defined by the Code) that could limit the Company's ability to utilize these carryforwards. At this time, the Company has not completed a study to assess whether an ownership change under Section 382 of the Code has occurred, or whether there have been multiple ownership changes since the Company's formation, due to the costs and complexities associated with such a study. The Company may have experienced various ownership changes, as defined by the Code, as a result of past financing transactions. Accordingly, the Company's ability to utilize the aforementioned carryforwards may be limited. Additionally, U.S. tax laws limit the time during which these carryforwards may be applied against future taxes. Therefore, the Company may not be able to take full advantage of these carryforwards for federal or state income tax purposes.

As of December 31, 2019 and 2018, the Company did not have any significant unrecognized tax benefits. The Company had not accrued interest or penalties related to uncertain tax positions.

The federal and state income tax returns are generally subject to tax examinations for the tax years ended December 31, 2016 through December 31, 2019. To the extent the Company has tax attribute carryforwards, the tax years in which the attribute was generated may still be adjusted upon examination by the Internal Revenue Service or state taxing authorities to the extent utilized in a future period.

Defined Contribution Benefit Plan	12 Months Ended
Defined Contribution Benefit Plan	Dec. 31, 2019
Defined Contribution Benefit Plan
Defined Contribution Benefit Plan	11. Defined Contribution Benefit Plan The Company sponsors a 401(k) retirement plan, in which substantially all of its employees are eligible to participate. Participants may contribute a percentage of their annual compensation to this plan, subject to statutory limitations. The Company did not provide any contributions to this plan during the years ended December 31, 2019 or 2018.

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2019
Subsequent Events
Subsequent Events	12. Subsequent Events The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the financial statements to provide additional evidence for certain estimates and to identify matters that require additional disclosure. Subsequent events have been evaluated as required. ATM Agreement Subsequent to December 31, 2019, the Company sold an aggregate of 173,572 shares of common stock pursuant to its current ATM program, at an average price of $6.29 per share, for gross and net proceeds of $1.1 million. January 2020 Financing On January 30, 2020, the Company entered into an underwriting agreement with Oppenheimer & Co. Inc. relating to an underwritten public offering of an aggregate of 5,290,000 shares of common stock at a price to the public of $5.00 per share, including 690,000 shares issued upon the exercise in full by Oppenheimer & Co. Inc. of its over-allotment option. This resulted in gross proceeds of $26.5 million, and net proceeds of $24.5 million.

Quarterly Financial Information (Unaudited)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information (unaudited)

Quarterly Financial Information (unaudited)

13. Quarterly Financial Information (unaudited, in thousands, except share and per share data)


	Three Months Ended
	March 31,		June 30,		September 30,		December 31,
	2019		2019		2019		2019
Operating expenses	$	6,334	$	7,325	$	6,682	$	6,747
Net loss		(6,038)		(7,131)		(6,514)		(6,610)
Net loss per share:
Basic and Diluted	$	(0.62)	$	(0.62)	$	(0.56)	$	(0.55)
Weighted-average common shares outstanding used in net loss per share:
Basic and Diluted		9,686,224		11,505,542		11,624,232		11,950,674


	Three Months Ended
	March 31,		June 30,		September 30,		December 31,
	2018		2018		2018		2018
Operating expenses	$	7,639	$	6,636	$	6,008	$	6,088
Net loss		(7,652)		(6,479)		(5,679)		(6,060)
Net loss per share:
Basic and Diluted	$	(2.88)	$	(1.98)	$	(0.80)	$	0.85
Weighted-average common shares outstanding used in net loss per share:
Basic and Diluted		2,655,584		3,272,877		7,103,841		7,115,507

Summary of Significant Accounting Polices (Polices)

12 Months Ended

Dec. 31, 2019

Summary of Significant Accounting Policies

Basis of Presentation and Principles of Consolidation

Use of Estimates

Off-Balance Sheet Risk and Concentrations of Credit Risk

Cash and Cash Equivalents and Restricted Cash


	December 31,
	2019		2018
Cash	$	2,530	$	4,390
Money market fund		5,432		5,956
Corporate debt securities		1,937		1,948
Reverse repurchase agreements		—		3,000
Total	$	9,899	$	15,294


	December 31,
	2019		2018
Cash and cash equivalents	$	9,899	$	15,294
Restricted cash (1)		477		113
Total	$	10,376	$	15,407

(1) Included in prepaid expenses and other current assets and other assets as of December 31, 2019 and other assets as of December 31, 2018 in the consolidated balance sheets

Short-Term Investments

Fair Value of Financial Instruments

Impairment of Long-Lived Assets

Research and Development Expenses

Stock-Based Compensation

The Company expenses restricted stock awards based on the fair value of the award on a straight-line basis over the associated service period of the award.


	Year Ended December 31,
	2019		2018
Research and development	$	616	$	673
General and administrative		896		1,098
Total	$	1,512	$	1,771

No related tax benefits were recognized for the years ended December 31, 2019 and 2018.

Net Loss Per Share

The following Common Stock equivalents were excluded from the calculation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect:


	Year Ended December 31,
	2019	2018
Stock options	785,832	433,389
Common stock warrants	6,193,749	4,202,449
	6,979,581	4,635,838

Recent Accounting Pronouncements - Adopted and not yet adopted

Recent Accounting Pronouncements—Adopted

Recent Accounting Pronouncements—Not Yet Adopted

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2019

Summary of Significant Accounting Policies

Schedule of cash and cash equivalents

Cash and cash equivalents consist of the following (in thousands):


	December 31,
	2019		2018
Cash	$	2,530	$	4,390
Money market fund		5,432		5,956
Corporate debt securities		1,937		1,948
Reverse repurchase agreements		—		3,000
Total	$	9,899	$	15,294

Schedule of reconciliation of cash, cash equivalents and restricted cash


	December 31,
	2019		2018
Cash and cash equivalents	$	9,899	$	15,294
Restricted cash (1)		477		113
Total	$	10,376	$	15,407

(1) Included in prepaid expenses and other current assets and other assets as of December 31, 2019 and other assets as of December 31, 2018 in the consolidated balance sheets

Schedule of stock-based compensation expense


	Year Ended December 31,
	2019		2018
Research and development	$	616	$	673
General and administrative		896		1,098
Total	$	1,512	$	1,771

Schedule of anti-dilutive common stock equivalents excluded from calculation of diluted net loss per share


	Year Ended December 31,
	2019	2018
Stock options	785,832	433,389
Common stock warrants	6,193,749	4,202,449
	6,979,581	4,635,838

Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2019

Financial Instruments

Summary of assets and liabilities measured at fair value on a recurring basis

Below is a summary of assets and liabilities measured at fair value on a recurring basis (in thousands):


	As of December 31, 2019
	Quoted Prices		Significant		Significant
	in Active		Observable		Unobservable
	Markets		Inputs		Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets:
Cash and cash equivalents:
Money market funds	$	5,432	$	—	$	—	$	5,432
Corporate debt securities		—		1,937		—		1,937
Short-term investments:
Commercial paper		—		1,993		—		1,993
Corporate debt securities		—		3,352		—		3,352
Reverse repurchase agreements		—		21,000		—		21,000
Total assets	$	5,432	$	28,282	$	—	$	33,714


	As of December 31, 2018
	Quoted Prices		Significant		Significant
	in Active		Observable		Unobservable
	Markets		Inputs		Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets:
Cash and cash equivalents:
Money market funds	$	5,956	$	—	$	—	$	5,956
Corporate debt securities		—		1,948		—		1,948
Reverse repurchase agreements		—		3,000		—		3,000
Short-term investments:
Corporate debt securities		—		7,276		—		7,276
Reverse repurchase agreements		—		15,000		—		15,000
Total assets	$	5,956	$	27,224	$	—	$	33,180

Short-Term Investments (Tables)

12 Months Ended

Dec. 31, 2019

Short-Term Investments

Summary of short-term investments

The following table summarizes the short-term investments held at December 31, 2019 and 2018 (in thousands):


			Gross Unrealized		Gross Unrealized
	Amortized Cost		Gains		Losses		Fair Value
December 31, 2019
Commercial paper	$	1,993	$	—	$	—	$	1,993
Corporate debt securities		3,352		—		—		3,352
Reverse repurchase agreements		21,000		—		—		21,000
Total	$	26,345	$	—	$	—	$	26,345


			Gross Unrealized		Gross Unrealized
	Amortized Cost		Gains		Losses		Fair Value
December 31, 2018
Corporate debt securities	$	7,280	$	—	$	(4)	$	7,276
Reverse repurchase agreements		15,000		—		—		15,000
Total	$	22,280	$	—	$	(4)	$	22,276

Accrued Expenses (Tables)

12 Months Ended

Dec. 31, 2019

Accrued Expenses

Schedule of accrued expenses

Accrued expenses consisted of the following (in thousands):


	December 31,
	2019		2018
Accrued compensation	$	1,365	$	1,241
Accrued contracted research costs		737		680
Accrued professional fees		370		393
Accrued other		98		109
Accrued franchise tax		40		168
Accrued severance		—		172
Total	$	2,610	$	2,763

Commitments (Tables)

12 Months Ended

Dec. 31, 2019

Commitments

Schedule of maturity analysis of the annual undiscounted cash flows of the operating lease liabilities

Future minimum payments required under the non-cancelable operating leases as of December 31, 2019 are summarized as follows (in thousands):


Period Ending December 31,	Amount
2020		1,449
2021		740
2022		438
Total minimum lease payments	$	2,627

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2019

Stockholders' Equity

Schedule of common Stock reserved for future issuance


	December 31,
	2019	2018
Warrants for the purchase of Common Stock	6,193,749	4,202,449
Options outstanding to purchase Common Stock	785,832	433,389
Options available for future issuance to purchase Common Stock	525,484	877,917
Shares reserved for the employee stock purchase plan	112,481	76,011
Total	7,617,546	5,589,766

Stock Incentive Plans (Tables)

12 Months Ended

Dec. 31, 2019

Stock Incentive Plans

Summary of stock option activity


				Weighted
				Average
		Weighted-		Remaining	Aggregate
		Average Exercise		Contractual	Intrinsic Value
	Shares	Price		Term (years)	(in thousands)
Outstanding at December 31, 2018	433,389	$	29.05	7.97	$	—
Granted	454,420	$	4.86
Cancelled or forfeited	(101,977)	$	18.12
Outstanding at December 31, 2019	785,832	$	16.48	8.13	$	470
Vested and Exercisable at December 31, 2019	289,782	$	33.91	6.59	$	9

Schedule of assumptions made based on the Black-Scholes option pricing model


	Year Ended December 31,
	2019				2018
Weighted-average expected volatility	68.9	-	110.5	%	73.7	-	76.9	%
Expected term (in years)	5.50	-	10.00		5.75	-	6.25
Risk-free interest rate	1.39	-	2.69	%	2.67	-	2.84	%
Expected dividend yield			0	%			0	%

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Income Taxes

Schedule of reconciliation of U.S. statutory income tax rate to effective tax rate


	Year Ended December 31,
	2019		2018
Federal income tax (benefit) at statutory rate	21.00	%	21.00	%
Permanent differences	(0.57)		(0.68)
Federal research and development credits and adjustments	2.42		4.25
State income tax, net of federal benefit	5.50		6.84
Other	0.49		(1.41)
Change in valuation allowance	(28.85)		(30.00)
Effective income tax rate	—	%	—	%

Schedule of components of deferred tax assets

The Company's deferred tax assets consisted of the following (in thousands):


	Year Ended December 31,
	2019		2018
Deferred tax assets
Net operating loss carryforwards	$	55,283	$	48,107
Tax credit carryforwards		8,030		7,174
Capitalized research and development		922		1,394
Capitalized legal expenses		1,073		1,132
Lease liability		639		—
Other differences		1,453		1,370
Total deferred tax assets		67,400		59,177
Deferred tax liabilities
ROU asset		(639)		—
Valuation allowance		(66,761)		(59,177)
Net deferred tax assets	$	—	$	—

Quarterly Financial Information (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information (unaudited)

Summary of unaudited quarterly results of operations

Quarterly Financial Information (unaudited, in thousands, except share and per share data)


	Three Months Ended
	March 31,		June 30,		September 30,		December 31,
	2019		2019		2019		2019
Operating expenses	$	6,334	$	7,325	$	6,682	$	6,747
Net loss		(6,038)		(7,131)		(6,514)		(6,610)
Net loss per share:
Basic and Diluted	$	(0.62)	$	(0.62)	$	(0.56)	$	(0.55)
Weighted-average common shares outstanding used in net loss per share:
Basic and Diluted		9,686,224		11,505,542		11,624,232		11,950,674


	Three Months Ended
	March 31,		June 30,		September 30,		December 31,
	2018		2018		2018		2018
Operating expenses	$	7,639	$	6,636	$	6,008	$	6,088
Net loss		(7,652)		(6,479)		(5,679)		(6,060)
Net loss per share:
Basic and Diluted	$	(2.88)	$	(1.98)	$	(0.80)	$	0.85
Weighted-average common shares outstanding used in net loss per share:
Basic and Diluted		2,655,584		3,272,877		7,103,841		7,115,507

Organization and Operations - Liquidity (Details) - USD ($) $ / shares in Units, $ in Thousands					1 Months Ended	12 Months Ended
	Jan. 30, 2020	Feb. 06, 2019	Jun. 19, 2018	Jul. 19, 2016	Jan. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stockholders' Equity
Gross proceeds from public offering						$ 6,996	$ 8,363
Accumulated deficit						(223,597)	$ (197,304)
Cash, cash equivalents and short-term investments						$ 36,200
Common stock
Stockholders' Equity
Number of shares issued						1,282,904	577,195
Gross proceeds from public offering						$ 1	$ 1
Common stock \| Cowen
Stockholders' Equity
Percentage of commission paid to underwriter based on proceeds from common stock				3.00%
Common stock \| ATM
Stockholders' Equity
Number of shares issued						1,282,904
Share price (in dollars per share)						$ 5.81
Gross proceeds from public offering						$ 7,500
Proceeds from public offering, net of issuance costs						$ 7,000
Common stock \| First ATM Program \| Cowen
Stockholders' Equity
Remaining available under sales agreement				$ 43,600
Common stock \| February 2019 Financing \| Oppenheimer & Co. Inc
Stockholders' Equity
Number of shares issued		4,000,000	4,200,000
Share price (in dollars per share)			$ 0.001
Number of warrants issued		2,000,000	4,200,000
Warrants price (in dollars per unit)		$ 5.00	$ 10.00
Gross proceeds from public offering			$ 42,000
Proceeds from public offering, net of issuance costs		$ 18,500	$ 38,900
Common stock \| January 2020 Financing \| Oppenheimer & Co. Inc
Stockholders' Equity
Share price (in dollars per share)	$ 5.00
Gross proceeds from public offering	$ 26,500
Subsequent Events \| ATM
Stockholders' Equity
Number of shares issued					173,572
Share price (in dollars per share)					$ 6.29
Gross proceeds from public offering					$ 1,100
Subsequent Events \| 2020 Equity financings
Stockholders' Equity
Proceeds from public offering, net of issuance costs					$ 25,600
Subsequent Events \| Common stock \| Over-Allotment option for underwriters \| Oppenheimer & Co. Inc
Stockholders' Equity
Number of shares issued	690,000
Subsequent Events \| Common stock \| January 2020 Financing \| Oppenheimer & Co. Inc
Stockholders' Equity
Number of shares issued	5,290,000
Proceeds from public offering, net of issuance costs	$ 24,500

Summary of Significant Accounting Polices - Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	$ 9,899	$ 15,294
Restricted cash	477	113
Total	10,376	15,407	$ 16,482
Cash
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	2,530	4,390
Money market fund
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	5,432	5,956
Corporate debt securities
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	$ 1,937	1,948
Reverse repurchase agreements
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents		$ 3,000

Summary of Significant Accounting Polices - Fair Value of Financial Instruments (Details)	12 Months Ended
	Dec. 31, 2019 USD ($)
Fair Value of Financial Instruments
Fair value assets, transfers from Level 1 to Level 2	$ 0
Fair value assets, transfers from Level 2 to Level 1	0
Fair value liabilities, transfers from Level 1 to Level 2	0
Fair value liabilities, transfers from Level 2 to Level 1	$ 0
Reverse repurchase agreements \| Government Securities and Obligations \| Minimum
Fair Value of Financial Instruments
Percentage of investment amount to collateralized deposits value	102.00%

Summary of Significant Accounting Policies - Stock-Based Compensation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Stock Incentive Plans
Stock-based compensation expense	$ 1,512,000	$ 1,771,000
Tax benefits recognized from stock-based compensation expense	0	0
Research and development
Stock Incentive Plans
Stock-based compensation expense	616,000	673,000
General and administrative
Stock Incentive Plans
Stock-based compensation expense	$ 896,000	$ 1,098,000

Summary of Significant Accounting Policies - Net Loss Per Share (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) segment shares	Dec. 31, 2018 shares	Nov. 30, 2019 USD ($)	Jan. 01, 2019 USD ($)
Antidilutive common stock equivalents excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from the calculation of diluted net loss per share (in shares) \| shares	6,979,581	4,635,838
Segment Information
Number of operating segments \| segment	1
Operating Lease, Right-of-Use Asset	$ 2,349		$ 1,700
Operating Lease, Liability, Current	$ 1,225
Operating Lease, Weighted Average Discount Rate, Percent			7.49%
Stock options
Antidilutive common stock equivalents excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from the calculation of diluted net loss per share (in shares) \| shares	785,832	433,389
Common stock warrants
Antidilutive common stock equivalents excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from the calculation of diluted net loss per share (in shares) \| shares	6,193,749	4,202,449
Restatement adjustment \| AccountingStandardsUpdate201602Member
Segment Information
Operating Lease, Right-of-Use Asset				$ 1,900
Operating Lease, Liability, Current				$ 1,900
Operating Lease, Weighted Average Discount Rate, Percent				7.49%

Financial Instruments (Details) - Recurring - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Summary of assets measured at fair value on a recurring basis
Total assets	$ 33,714	$ 33,180
Level 1
Summary of assets measured at fair value on a recurring basis
Total assets	5,432	5,956
Level 2
Summary of assets measured at fair value on a recurring basis
Total assets	28,282	27,224
Money market fund
Summary of assets measured at fair value on a recurring basis
Cash and cash equivalents	5,432	5,956
Money market fund \| Level 1
Summary of assets measured at fair value on a recurring basis
Cash and cash equivalents	5,432	5,956
Commercial Paper
Summary of assets measured at fair value on a recurring basis
Short-term investments	1,993
Commercial Paper \| Level 2
Summary of assets measured at fair value on a recurring basis
Short-term investments	1,993
Corporate debt securities
Summary of assets measured at fair value on a recurring basis
Cash and cash equivalents	1,937	1,948
Short-term investments	3,352	7,276
Corporate debt securities \| Level 2
Summary of assets measured at fair value on a recurring basis
Cash and cash equivalents	1,937	1,948
Short-term investments	3,352	7,276
Reverse repurchase agreements
Summary of assets measured at fair value on a recurring basis
Cash and cash equivalents		3,000
Short-term investments	21,000	15,000
Reverse repurchase agreements \| Level 2
Summary of assets measured at fair value on a recurring basis
Cash and cash equivalents		3,000
Short-term investments	$ 21,000	$ 15,000

Short-Term Investments (Details) $ in Thousands	12 Months Ended
Short-Term Investments (Details) $ in Thousands	Dec. 31, 2019 USD ($) instrument	Dec. 31, 2018 USD ($) instrument
Short-Term Investments
Amortized Cost	$ 26,345	$ 22,280
Gross Unrealized Losses		(4)
Fair Value	$ 26,345	$ 22,276
Number of short term investments in unrealized loss position \| instrument	4	7
Number of short term investments in an unrealized loss position more than 12 months \| instrument	0	0
Aggregate fair value of the investments in an unrealized loss position	$ 3,400	$ 7,300
Commercial Paper
Short-Term Investments
Amortized Cost	1,993
Fair Value	1,993
Corporate debt securities
Short-Term Investments
Amortized Cost	3,352	7,280
Gross Unrealized Losses		(4)
Fair Value	3,352	7,276
Reverse repurchase agreements
Short-Term Investments
Amortized Cost	21,000	15,000
Fair Value	$ 21,000	$ 15,000

Restricted Cash (Details) $ in Millions	Dec. 31, 2019 USD ($)
Letter of Credit
Restricted Cash
Security deposits held for operating lease agreements	$ 0.5

Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accrued Expenses
Accrued compensation	$ 1,365	$ 1,241
Accrued contracted research costs	737	680
Accrued professional fees	370	393
Accrued other	98	109
Accrued franchise tax	40	168
Accrued severance		172
Total	$ 2,610	$ 2,763

Commitments (Details) - USD ($) $ in Thousands	12 Months Ended
Commitments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Nov. 30, 2019
Maturity analysis of undiscounted cash flows of operating lease liabilities
2020	$ 1,449
2021	740
2022	438
Total minimum lease payments	2,627
Rent expense (Topic 842)	400
Rent expense (Topic 840)		$ 1,100
Lease payments (Topic 842)	1,400	1,400
Sublease
Future sublease income to be received in the next twelve months	500
Sublease income received	1,000	$ 300
Operating Lease, Right-of-Use Asset	$ 2,349		$ 1,700
Operating Lease, Liability			$ 1,700
Operating Lease, Weighted Average Discount Rate, Percent			7.49%

Stockholders' Equity (Details)		12 Months Ended
Stockholders' Equity (Details)	Dec. 31, 2019 $ / shares shares	Dec. 31, 2019 series Vote $ / shares shares	Feb. 28, 2019 $ / shares shares	Dec. 31, 2018 $ / shares shares	Jun. 30, 2018 $ / shares shares
Preferred Stock
Preferred stock, authorized (in shares)	5,000,000	5,000,000		5,000,000
Preferred stock, par value (in dollars per share) \| $ / shares	$ 0.001	$ 0.001		$ 0.001
Preferred stock, issued (in shares)	0	0		0
Preferred stock, outstanding (in shares)	0	0		0
Minimum number of series used to issue preferred stock \| series		1
Common Stock
Common stock, authorized (in shares)	150,000,000	150,000,000		150,000,000
Par value of common stock (in dollars per share) \| $ / shares	$ 0.001	$ 0.001		$ 0.001
Common stock, issued (in shares)	12,433,600	12,433,600		7,141,996
Common Stock, outstanding (in shares)	12,433,600	12,433,600		7,141,996
Number of votes entitled to each common stock share \| Vote		1
Common stock dividends, declared or paid (in dollars per share) \| $ / shares		$ 0
Shares reserved for future issuance (in shares)	7,617,546	7,617,546		5,589,766
Common stock warrants
Common Stock
Shares reserved for future issuance (in shares)	6,193,749	6,193,749		4,202,449
Common stock options outstanding
Common Stock
Shares reserved for future issuance (in shares)	785,832	785,832		433,389
Common stock options available for future issuance
Common Stock
Shares reserved for future issuance (in shares)	525,484	525,484		877,917
Employee stock purchase plan
Common Stock
Shares reserved for future issuance (in shares)	112,481	112,481		76,011
June 2018 Warrants
Common Stock Warrants
Weighted average remaining contractual life		3 years 5 months 19 days
June 2018 Warrants \| Common stock warrants
Common Stock Warrants
Number of shares which may be purchased with warrants					4,200,000
Exercise price of warrants (in dollars per share) \| $ / shares					$ 12.00
Warrants term					5 years
February 2019 Warrants \| Common stock warrants
Common Stock Warrants
Number of shares which may be purchased with warrants			2,000,000
Exercise price of warrants (in dollars per share) \| $ / shares			$ 6.25
Warrants term			5 years
Class of Warrant or Right, Outstanding	1,991,300	1,991,300
Weighted average remaining contractual life	4 years 1 month 10 days

Stock Incentive Plans - Plan Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Stock Incentive Plans
Shares reserved for future issuance (in shares)	7,617,546	5,589,766
Shares
Outstanding, beginning of period (in shares)	433,389
Granted (in shares)	454,420
Cancelled or forfeited (in shares)	(101,977)
Outstanding, end of period (in shares)	785,832	433,389
Vested and Exercisable (in shares)	289,782
Weighted-Average Exercise Price
Outstanding, beginning of period (in dollars per share)	$ 29.05
Granted (in dollars per share)	4.86
Cancelled or forfeited (in dollars per share)	18.12
Outstanding at end of year (in dollars per share)	16.48	$ 29.05
Vested and Exercisable (in dollars per share)	$ 33.91
Weighted Average Remaining Contractual Term (years)
Outstanding	8 years 1 month 17 days	7 years 11 months 19 days
Vested and Exercisable	6 years 7 months 2 days
Aggregate Intrinsic Value
Outstanding	$ 470
Vested and Exercisable	$ 9
Exercised (in shares)	0
Stock options
Stock Incentive Plans
Vesting period	4 years
Cliff period for vesting	1 year
Expiration period	10 years
Aggregate Intrinsic Value
Intrinsic value of options exercised		$ 1
Aggregate fair value of options vested	$ 1,500	$ 1,700
Weighted average grant date fair value of options granted (in dollars per share)	$ 3.25	$ 6.64
Unrecognized compensation expense related to unvested stock option awards	$ 1,700
Weighted-average amortization period over which cost is expected to be recognized	2 years 2 months 12 days

Stock Incentive Plans - Stock-Based Compensation Expense (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Assumptions used to calculate fair value of stock options
Expected dividend yield	0.00%	0.00%
Minimum
Assumptions used to calculate fair value of stock options
Weighted-average expected volatility	68.90%	73.70%
Expected term (in years)	5 years 6 months	5 years 9 months
Risk-free interest rate	1.39%	2.67%
Maximum
Assumptions used to calculate fair value of stock options
Weighted-average expected volatility	110.50%	76.90%
Expected term (in years)	10 years	6 years 3 months
Risk-free interest rate	2.69%	2.84%

Stock Incentive Plans - Employee Stock Purchase Plan (Details) - shares	Dec. 31, 2019	Dec. 31, 2018
Stock Incentive Plans
Common Stock, Issued, (in shares)	12,433,600	7,141,996

Income Taxes - Reconciliation of effective tax rate (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of the U.S. statutory income tax rate to the effective income tax rate
Federal income tax (benefit) at statutory rate	21.00%	21.00%
Permanent differences	(0.57%)	(0.68%)
Federal research and development credits and adjustments	2.42%	4.25%
State income tax benefit, net of federal benefit	5.50%	6.84%
Other	0.49%	(1.41%)
Change in valuation allowance	(28.85%)	(30.00%)
Effective income tax rate	0.00%	0.00%

Income Taxes - Deferred tax assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets
Net operating loss carryforwards	$ 55,283	$ 48,107
Tax credit carryforwards	8,030	7,174
Capitalized research and development	922	1,394
Capitalized legal expenses	1,073	1,132
Lease liability	639
Other differences	1,453	1,370
Total deferred tax assets	67,400	59,177
Deferred tax liabilities
ROU asset	(639)
Valuation allowance	(66,761)	(59,177)
Increase in valuation allowance	$ 7,600	$ (7,800)
Federal income tax (benefit) at statutory rate	21.00%	21.00%

Income Taxes - Operating Loss Carryforwards (Details) $ in Millions	Dec. 31, 2019 USD ($)
Federal
Operating loss carryforwards
Net operating loss	$ 203.0
Tax credit carryforwards	6.3
Federal \| Tax Years 2023 through 2039
Operating loss carryforwards
Net operating loss	150.5
Federal \| No expiration
Operating loss carryforwards
Net operating loss	52.5
State
Operating loss carryforwards
Net operating loss	200.2
Tax credit carryforwards	2.2
State \| Tax Years 2023 through 2039
Operating loss carryforwards
Net operating loss	$ 200.2

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	12 Months Ended
	Jan. 30, 2020	Jan. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Subsequent Event [Line Items]
Stock Issued During Period, Value, New Issues			$ 6,996	$ 8,363
Common stock
Subsequent Event [Line Items]
Stock Issued During Period, Shares, New Issues			1,282,904	577,195
Stock Issued During Period, Value, New Issues			$ 1	$ 1
ATM \| Common stock
Subsequent Event [Line Items]
Stock Issued During Period, Shares, New Issues			1,282,904
Shares Issued, Price Per Share			$ 5.81
Stock Issued During Period, Value, New Issues			$ 7,500
Proceeds from Issuance of Common Stock			$ 7,000
ATM \| Subsequent Events
Subsequent Event [Line Items]
Stock Issued During Period, Shares, New Issues		173,572
Shares Issued, Price Per Share		$ 6.29
Stock Issued During Period, Value, New Issues		$ 1,100
January 2020 Financing \| Oppenheimer & Co. Inc \| Common stock
Subsequent Event [Line Items]
Shares Issued, Price Per Share	$ 5.00
Stock Issued During Period, Value, New Issues	$ 26,500
January 2020 Financing \| Subsequent Events \| Oppenheimer & Co. Inc \| Common stock
Subsequent Event [Line Items]
Stock Issued During Period, Shares, New Issues	5,290,000
Proceeds from Issuance of Common Stock	$ 24,500
Over-Allotment option for underwriters \| Subsequent Events \| Oppenheimer & Co. Inc \| Common stock
Subsequent Event [Line Items]
Stock Issued During Period, Shares, New Issues	690,000

Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information (Unaudited)
Operating expenses	$ 6,747	$ 6,682	$ 7,325	$ 6,334	$ 6,088	$ 6,008	$ 6,636	$ 7,639	$ 27,088	$ 26,371
Net loss	$ (6,610)	$ (6,514)	$ (7,131)	$ (6,038)	$ (6,060)	$ (5,679)	$ (6,479)	$ (7,652)	$ (26,293)	$ (25,870)
Net loss per share:
Basic and Diluted (in dollars per share)	$ (0.55)	$ (0.56)	$ (0.62)	$ (0.62)	$ 0.85	$ (0.80)	$ (1.98)	$ (2.88)	$ (2.35)	$ (5.12)
Weighted-average common shares outstanding used in net loss per share:
Basic and Diluted (in shares)	11,950,674	11,624,232	11,505,542	9,686,224	7,115,507	7,103,841	3,272,877	2,655,584	11,199,057	5,054,823

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details