Leap Therapeutics (LPTX) 10-Q 9 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Aug. 06, 2019
Document and Entity Information
Entity Registrant Name	LEAP THERAPEUTICS, INC.
Entity Central Index Key	0001509745
Document Type	10-Q
Document Period End Date	Jun. 30, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		24,038,799
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 15,747	$ 16,284
Research and development incentive receivable	836	836
Prepaid expenses and other current assets	211	202
Total current assets	16,794	17,322
Property and equipment, net	161	86
Right of use asset, net	1,398
Research and development incentive receivable, net of current portion	135
Deferred tax assets	124	124
Other assets	1,525	1,542
Total assets	20,137	19,074
Current liabilities:
Accounts payable	5,325	3,579
Accrued expenses	2,474	2,872
Lease liability - current portion	657
Total current liabilities	8,456	6,451
Non current liabilities:
Warrant liability		3,448
Lease liability, net of current portion	742
Total liabilities	9,198	9,899
Commitments and contingencies (Note 9)
Stockholders' equity:
Common stock, $0.001 par value; 100,000,000 shares authorized as of June 30, 2019 and December 31, 2018, 22,949,064 and 14,703,159 shares issued and outstanding as of June 30, 2019 and December 31, 2018, respectively	23	15
Additional paid-in capital	189,831	162,393
Accumulated other comprehensive income	322	302
Accumulated deficit	(179,237)	(153,535)
Total stockholders' equity	10,939	9,175
Total liabilities and stockholders' equity	$ 20,137	$ 19,074

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Jun. 30, 2019	Dec. 31, 2018
CONDENSED CONSOLIDATED BALANCE SHEETS
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized shares	100,000,000	100,000,000
Common stock, issued shares	22,949,064	14,703,159
Common stock, outstanding shares	22,949,064	14,703,159

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Operating expenses:
Research and development	$ 6,136	$ 4,234	$ 12,926	$ 8,465
General and administrative	2,325	2,603	4,330	4,716
Total operating expenses	8,461	6,837	17,256	13,181
Loss from operations	(8,461)	(6,837)	(17,256)	(13,181)
Interest income	119	122	201	199
Interest expense	(9)	(8)	(16)	(14)
Australian research and development incentives	61	243	136	889
Foreign currency losses	(76)	(222)	(34)	(366)
Change in fair value of warrant liability		(662)		(5,513)
Net loss	(8,366)	(7,364)	(16,969)	(17,986)
Dividend attributable to down round feature of warrants			(359)
Net loss attributable to common stockholders	$ (8,366)	$ (7,364)	$ (17,328)	$ (17,986)
Net loss per share - basic and diluted (in dollars per share)	$ (0.37)	$ (0.50)	$ (0.82)	$ (1.32)
Weighted average common shares outstanding - basic and diluted (in shares)	22,906,025	14,691,890	21,081,869	13,576,850

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
Net loss	$ (8,366)	$ (7,364)	$ (16,969)	$ (17,986)
Other comprehensive income:
Foreign currency translation adjustments	44	139	20	249
Comprehensive loss	$ (8,322)	$ (7,225)	$ (16,949)	$ (17,737)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Total
Balance at the beginning of the period (in shares) at Dec. 31, 2017	12,354,014
Increase (Decrease) in Shares Outstanding
Issuance of stock (in shares)	2,146,667
Issuance of common stock upon exercise of warrants (in shares)	200,000
Balance at the end of the period (in shares) at Jun. 30, 2018	14,700,681
Balance at the beginning of the period at Dec. 31, 2017	$ 12	$ 141,770	$ (268)	$ (130,397)	$ 11,117
Increase (Decrease) in Stockholders' Equity
Issuance of common stock, net of issuance costs	3	14,793			14,796
Issuance of common stock upon exercise of warrants		2,347			2,347
Foreign currency translation adjustment			249		249
Stock-based compensation		1,612			1,612
Net loss				(17,986)	(17,986)
Balance at the end of the period at Jun. 30, 2018	$ 15	160,522	(19)	(148,383)	12,135
Balance at the beginning of the period (in shares) at Mar. 31, 2018	14,500,681
Increase (Decrease) in Shares Outstanding
Issuance of common stock upon exercise of warrants (in shares)	200,000
Balance at the end of the period (in shares) at Jun. 30, 2018	14,700,681
Balance at the beginning of the period at Mar. 31, 2018	$ 15	157,290	(158)	(141,019)	16,128
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon exercise of warrants		2,347			2,347
Foreign currency translation adjustment			139		139
Stock-based compensation		885			885
Net loss				(7,364)	(7,364)
Balance at the end of the period at Jun. 30, 2018	$ 15	160,522	(19)	(148,383)	$ 12,135
Balance at the beginning of the period (in shares) at Dec. 31, 2018	14,703,159
Increase (Decrease) in Shares Outstanding
Issuance of stock (in shares)	7,557,142
Issuance of common stock through ATM sales (in shares)	688,763				688,763
Balance at the end of the period (in shares) at Jun. 30, 2019	22,949,064
Balance at the beginning of the period at Dec. 31, 2018	$ 15	162,393	302	(153,535)	$ 9,175
Increase (Decrease) in Stockholders' Equity
Reclassification of 2017 Warrants from liability to equity upon adoption of ASU 2017-11		11,821		(8,374)	3,447
Issuance of common stock, net of issuance costs	7	12,115			12,122
Record the value of the effect of the down round feature as a dividend		359		(359)
Issuance of common stock through ATM sales	1	1,305			1,306
To record ATM issuance costs in Additional Paid-in Capital		(8)			(8)
Foreign currency translation adjustment			20		20
Stock-based compensation		1,846			1,846
Net loss				(16,969)	(16,969)
Balance at the end of the period at Jun. 30, 2019	$ 23	189,831	322	(179,237)	10,939
Balance at the beginning of the period (in shares) at Mar. 31, 2019	22,260,301
Increase (Decrease) in Shares Outstanding
Issuance of common stock through ATM sales (in shares)	688,763
Balance at the end of the period (in shares) at Jun. 30, 2019	22,949,064
Balance at the beginning of the period at Mar. 31, 2019	$ 22	187,635	278	(170,871)	17,064
Increase (Decrease) in Stockholders' Equity
Issuance of common stock through ATM sales	1	1,305			1,306
To record ATM issuance costs in Additional Paid-in Capital		(8)			(8)
Foreign currency translation adjustment			44		44
Stock-based compensation		899			899
Net loss				(8,366)	(8,366)
Balance at the end of the period at Jun. 30, 2019	$ 23	$ 189,831	$ 322	$ (179,237)	$ 10,939

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Public Offering
CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIENCY)
Issuance of common stock, issuance costs	$ 1,102	$ 1,304

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net loss	$ (16,969)	$ (17,986)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	25	24
Non-cash lease expense	357
Stock-based compensation expense	1,846	1,612
Change in fair value of warrant liability		5,513
Changes in operating assets and liabilities:
Prepaid expenses and other assets	9	(570)
Research and development incentive receivable	(139)	(168)
Accounts payable and accrued expenses	1,141	44
Lease Liability	(321)
Net cash used in operating activities	(14,051)	(11,531)
Cash flows from investing activities:
Purchases of property and equipment	(100)
Net cash used in investing activities	(100)
Cash flows from financing activities:
Proceeds from the issuance of common stock, net of underwriter commissions and discounts	12,331	15,034
Proceeds from issuance of common stock from ATM sales	1,306
Proceeds from the exercise of common stock warrants		1,217
Payment of deferred offering costs	(55)	(238)
Net cash provided by financing activities	13,582	16,013
Effect of exchange rate changes on cash and cash equivalents	32	262
Net increase (decrease) in cash and cash equivalents	(537)	4,744
Cash and cash equivalents at beginning of period	16,284	25,737
Cash and cash equivalents at end of period	15,747	30,481
Supplemental disclosure of non-cash financing activities:
Reduction in fair value of warrant liability as a result of exercise of common stock warrants		$ 1,130
Reclassification of 2017 Warrants from liability to equity	3,447
Dividend attributable to down round feature of warrants	359
Offering costs included in accounts payable and accrued expenses	154
Right-of-use asset recorded upon adoption of ASU 2016-02	1,755
Lease liability recorded upon adoption of ASU 2016-02	1,720
Accrued rent reclassified upon adoption of ASU 216-02	$ 35

Nature of Business, Basis of Pr

Nature of Business, Basis of Presentation and Liquidity	6 Months Ended
	Jun. 30, 2019
Nature of Business, Basis of Presentation and Liquidity
Nature of Business, Basis of Presentation and Liquidity	1. Nature of Business, Basis of Presentation and Liquidity Nature of Business Leap Therapeutics, Inc. was incorporated in the state of Delaware on January 3, 2011 and changed its name to Leap Therapeutics, Inc. effective November 16, 2015 (the “Company”). During 2015, HealthCare Pharmaceuticals Pty Ltd. (“HCP Australia”) was formed and is a wholly owned subsidiary of the Company. The Company is a biopharmaceutical company acquiring and developing novel therapeutics at the leading edge of cancer biology. The Company’s approach is designed to target compelling tumor-promoting and immuno-oncology pathways to generate durable clinical benefit and enhanced outcomes for patients. The Company’s programs are monoclonal antibodies that target key cellular pathways that enable cancer to grow and spread and specific mechanisms that activate the body’s immune system to identify and attack cancer. Basis of Presentation The accompanying condensed consolidated financial statements as of June 30, 2019 and for the three and six months ended June 30, 2019 and 2018 have been prepared by the Company, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted pursuant to such rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. These condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K filed with the SEC on April 1, 2019. The condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements. In the opinion of management, the accompanying condensed consolidated financial statements contain all adjustments which are necessary for the fair presentation of the Company’s financial position as of June 30, 2019, statements of operations and statements of comprehensive loss for the three and six months ended June 30, 2019 and 2018 and statements of cash flows for the six months ended June 30, 2019 and 2018. Such adjustments are of a normal and recurring nature. The results of operations for the three and six months ended June 30, 2019 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2019. Liquidity Since inception, the Company has been engaged in organizational activities, including raising capital, and research and development activities. The Company does not yet have a product that has been approved by the Food and Drug Administration (the “FDA”), has not generated any revenues and has not yet achieved profitable operations, nor has it ever generated positive cash flows from operations. There is no assurance that profitable operations, if achieved, could be sustained on a continuing basis. Further, the Company’s future operations are dependent on the success of the Company’s efforts to raise additional capital, its research and commercialization efforts, regulatory approval, and, ultimately, the market acceptance of the Company’s products . In accordance with Accounting Standards Codification (“ASC”) 205-40, Going Concern, the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the condensed consolidated financial statements are issued. As of June 30, 2019, the Company had cash and cash equivalents of $15,747 and expects to receive $836 of research and development tax incentive payments in 2019 from the Commonwealth of Australia as a result of the 2018 research and development activities of the Company’s Australian subsidiary, HCP Australia. Additionally, the Company had an accumulated deficit of $179,237 at June 30, 2019, and during the six months ended June 30, 2019, the Company incurred a net loss of $16, 969. The Company expects to continue to generate operating losses in the foreseeable future. Due to the Company’s need for additional capital and the uncertainties surrounding the Company’s ability to raise such funding, substantial doubt exists as to the Company’s ability to continue as a going concern for a period through one year after the financial statements have been issued . On July 10, 2019, the Company entered into a purchase agreement (the “Commitment Purchase Agreement”) and a Registration Rights Agreement (the “Registration Rights Agreement”) with Lincoln Park Capital Fund, LLC (“Lincoln Park”), pursuant to which the Company has the right to sell to Lincoln Park up to $20,000 in shares of its common stock, $0.001 par value per share (“Common Stock”), subject to certain limitations and conditions set forth in the Commitment Purchase Agreement. On July 11, 2019, the Company entered into a purchase agreement (the “Registered Offering Purchase Agreement” and together with the Commitment Purchase Agreement, the “Purchase Agreements”), under which the Company agreed to sell to Lincoln Park, and Lincoln Park agreed to purchase 571,429 shares of its Common Stock, at a price of $1.75 per share for an aggregate purchase price of $1,000, pursuant to the Company’s shelf registration statement on Form S-3 filed with the SEC, including the prospectus supplement thereto dated July 11, 2019. In addition, the Company will seek additional funding through public or private equity financings or government programs and will seek funding or development program cost-sharing through collaboration agreements or licenses with larger pharmaceutical or biotechnology companies. If the Company does not obtain additional funding or development program cost-sharing, the Company would be forced to delay, reduce or eliminate certain clinical trials or research and development programs, reduce or eliminate discretionary operating expenses, and delay company and pipeline expansion, which would adversely affect its business prospects. The inability to obtain funding, as and when needed, would have a negative impact on the Company’s financial condition and ability to pursue its business strategies.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2019
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Principles of Consolidation The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions are eliminated upon consolidation. Use of Estimates The presentation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Research and development incentive income and receivable The Company recognizes other income from Australian research and development incentives when there is reasonable assurance that the income will be received, the relevant expenditure has been incurred, and the consideration can be reliably measured. The research and development incentive is one of the key elements of the Australian Government’s support for Australia’s innovation system and is supported by legislative law primarily in the form of the Australian Income Tax Assessment Act 1997, as long as eligibility criteria are met. Management has assessed the Company’s research and development activities and expenditures to determine which activities and expenditures are likely to be eligible under the research and development incentive regime described above. At each period end, management estimates the refundable tax offset available to the Company based on available information at the time. This estimate is also reviewed by external tax advisors on an annual basis. Under the program, a percentage of eligible research and development expenses incurred by the Company through its subsidiary in Australia are reimbursed. The percentage was 43.5% for the year ended December 31, 2018 and for the three and six months ended June 30, 2019. The research and development incentive receivable represents an amount due in connection with the above program. The Company has recorded a research and development incentive receivable of $971 and $836 as of June 30, 2019 and December 31, 2018, respectively, in the condensed consolidated balance sheets and other income from Australian research and development incentives of $61 and $243, respectively, for the three months ended June 30, 2019 and 2018 and $136 and $889 for the six months ended June 30, 2019 and 2018, respectively, in the condensed consolidated statements of operations related to refundable research and development incentive program payments in Australia. The following table shows the change in the research and development incentive receivable from December 31, 2017 to June 30, 2019 (in thousands): Balance at December 31, 2017 $ 1,744 Australian research and development incentive income 756 Cash received for 2016 eligible overseas research and development expenses (740) Cash received for 2017 eligible expenses (793) Foreign currency translation (131) Balance at December 31, 2018 836 Australian research and development incentive income 136 Foreign currency translation (1) Balance at June 30, 2019 $ 971 Foreign Currency Translation The financial statements of the Company’s Australian subsidiary are measured using the local currency as the functional currency. Assets and liabilities of this subsidiary are translated into U.S. dollars at an exchange rate as of the consolidated balance sheet date. Equity is translated at historical exchange rates. Revenues and expenses are translated into U.S. dollars at average rates of exchange in effect during the year. The resulting cumulative translation adjustments have been recorded as a separate component of stockholders’ equity. Realized foreign currency transaction gains and losses are included in the results of operations. Other Assets Other assets as of June 30, 2019 and December 31, 2018 included $1,344 and $1,380, respectively, of deposits made by the Company with certain service providers that are to be applied to future payments due under the service agreements or returned to the Company if not utilized. In addition, as of June 30, 2019 and December 31, 2018 other assets included $181 and $162 of deferred issuance costs, respectively. Warrants On January 1, 2019, the Company adopted ASU No. 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), and Derivatives and Hedging (Topic 815) ("ASU 2017-11"), which changes the classification analysis of certain equity-linked financial instruments (or embedded features) with down round features. The amendments require entities that present earnings per share ("EPS") in accordance with Topic 260 to recognize the effect of the down round feature when triggered with the effect treated as a dividend and as a reduction of income available to common shareholders in basic EPS. The Company concluded that the common stock warrants (the “2017 Warrants”) issued in connection with the private placement of common stock completed in November 2017 (the “Private Placement”), qualify for equity classification. The adoption guidance of ASU 2017-11 provides for a modified retrospective adoption. The Company applied the guidance retrospectively to the 2017 Warrants by means of a cumulative-effect adjustment to its statement of financial position as of the beginning of the interim and annual period beginning January 1, 2019. The Company performed a final remeasurement of the warrant liability as of January 1, 2019 and reclassified $3,448 to additional paid-in capital. The Company will recognize on a prospective basis the value of the effect of the down round feature in the 2017 Warrants when it is triggered (i.e., when the exercise price is adjusted downward). This value is measured as the difference between (1) the financial instrument’s fair value (without the down round feature) using the pre-trigger exercise price and (2) the financial instrument’s fair value (with the down round feature) using the reduced exercise price. The value of the effect of the down round feature will be treated as a dividend and a reduction to income available to common shareholders in the basic EPS calculation. In connection with the public offering, completed in February 2019 (the “2019 Public Offering”), when the 2017 Warrants were repriced from $6.085 to $1.75 as a result of a down round, the Company recorded a dividend of $359 during the six months ended June 30, 2019. Fair Value of Financial Instruments Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: · Level 1—Quoted prices in active markets for identical assets or liabilities. · Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. · Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. During the periods presented, the Company has not changed the manner in which it values assets and liabilities that are measured at fair value using Level 3 inputs. The Company recognizes transfers between levels of the fair value hierarchy as of the end of the reporting period. There were no transfers within the hierarchy during the three and six months ended June 30, 2019 and the year ended December 31, 2018. A summary of the assets and liabilities carried at fair value in accordance with the hierarchy defined above is as follows (in thousands): Total Level 1 Level 2 Level 3 June 30, 2019 Assets: Cash equivalents $ 15,747 $ 15,747 $ — $ — Total assets $ 15,747 $ 15,747 $ — $ — December 31, 2018 Assets: Cash equivalents $ 16,284 $ 16,284 $ — $ — Total assets $ 16,284 $ 16,284 $ — $ — Liabilities: Warrant liability $ 3,448 $ — $ — $ 3,448 Total liabilities $ 3,448 $ — $ — $ 3,448 Cash equivalents of $15,747 and $16,284 as of June 30, 2019 and December 31, 2018, respectively, consisted of overnight investments and money market funds and are classified within Level 1 of the fair value hierarchy because they are valued using quoted market prices in active markets. The carrying value of the research and development incentive receivable, accounts payable and accrued liabilities approximate their fair value due to the short-term nature of these assets and liabilities. A roll-forward of the recurring fair value measurements of the warrant liability categorized with Level 3 inputs is as follows (in thousands): Warrant Liability Balance—December 31, 2017 $ 11,862 Change in fair value 4,851 Balance—March 31, 2018 16,713 Exercise of warrants (1,130) Change in Fair value 662 Balance—June 30, 2018 16,245 Change in Fair value (1,793) Balance—September 30, 2018 14,452 Change in Fair value (11,004) Balance—December 31, 2018 3,448 Final remeasurement and reclassification of 2017 Warrants to equity in connection with the adoption of ASU 2017-11 (3,448) Balance—January 1, 2019 $ — The warrant liability in the table above is composed of the fair value of the 2017 Warrants that the Company issued in connection with the Private Placement. The fair value of the warrant liability was determined based on significant inputs not observable in the market, which represents a Level 3 measurement within the fair value hierarchy. The Company utilized a Monte Carlo simulation, which is a statistical method used to generate a defined number of share price paths to develop a reasonable estimate of the range of the future expected share prices, to value the warrant liability. The Monte Carlo simulation incorporated assumptions and estimates to value the warrant liability. Estimates and assumptions impacting the fair value measurement included the estimated probability of adjusting the exercise price of the warrants, the number of shares for which the warrants will be exercisable, the remaining contractual term of the warrants, the risk-free interest rate, the expected dividend yield, and the expected volatility of the price of the underlying common shares. The Company historically had been a private company and lacks company-specific historical and implied volatility information of its shares. Therefore, it estimated its expected share volatility based on the historical volatility of publicly traded peer companies for a term equal to the remaining contractual term of the warrants. The risk-free interest rate was determined by reference to the U.S. Treasury yield curve for time periods approximately equal to the remaining contractual term of the warrants. The Company estimated a 0% expected dividend yield based on the fact that the Company has never paid or declared dividends and does not intend to do so in the foreseeable future. Leases In February 2016, the FASB issued ASU 2016-02, Leases, or ASU 2016-02, to enhance the transparency and comparability of financial reporting related to leasing arrangements. The Company adopted ASU 2016-02 on January 1, 2019, or the effective date, and used the effective date as its date of initial application. At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the unique facts and circumstances present. Most leases with a term greater than one year are recognized on the balance sheet as right-of-use assets, lease liabilities and, if applicable, long-term lease liabilities. The Company has elected not to recognize on the balance sheet leases with terms of one year or less. Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of lease payments over the expected remaining lease term. The Company has determined that the rate implicit in the lease is not determinable and the Company does not have borrowings with similar terms and collateral. Therefore, the Company considered a variety of factors, including observable debt yields from comparable companies and the volatility in the debt market for securities with similar terms, in determining that 8% was reasonable to use as the incremental borrowing rate for purposes of the calculation of lease liabilities. In accordance with the guidance in ASU 2016-02, components of a lease should be split into three categories: lease components (e.g. land, building, etc.), non-lease components (e.g. common area maintenance, maintenance, consumables, etc.), and non-components (e.g. property taxes, insurance, etc.). Then the fixed and in-substance fixed contract consideration (including any related to non-components) must be allocated based on fair values to the lease components and non-lease components. Although separation of lease and non-lease components is required, certain practical expedients are available. Entities may elect the practical expedient to not separate lease and non-lease components. Rather, they would account for each lease component and the related non-lease component together as a single component. The Company has elected to account for the lease and non-lease components of each of its operating leases as a single lease component and allocate all of the contract consideration to the lease component only. The lease component results in an operating right-of-use asset being recorded on the consolidated balance sheets and amortized such that lease expense is recorded on a straight line basis over the term of the lease. Net Loss per Share Basic net loss per share is computed using the weighted average number of common shares outstanding during the period. Diluted net loss per share is computed using the weighted average number of common shares outstanding during the period and, if dilutive, the weighted average number of potential shares of common stock, including the assumed exercise of stock options and warrants. Warrant Liability In connection with entering into the Private Placement, the Company issued the 2017 Warrants with each share of common stock sold in the Private Placement. The Company classified the 2017 Warrants as a liability on its consolidated balance sheet prior to January 1, 2019, because each warrant represented a freestanding financial instrument that is not indexed to the Company’s own shares. The warrant liability was initially recorded at fair value upon entering into the Private Placement agreement and was subsequently remeasured to fair value at each reporting date. Changes in the fair value of the warrant liability were recognized as gains (losses) in the condensed consolidated statement of operations through the year ended December 31, 2018. 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 or to identify matters that require additional disclosure. Subsequent events have been evaluated as required. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board, or FASB, and are early adopted by the Company or adopted as of the specified effective date. In June 2018, the FASB issued ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting, which is intended to simplify the accounting for share-based payments to nonemployees by aligning it with the accounting for share-based payments to employees, with certain exceptions. The Company adopted this standard effective January 1, 2019, which had no impact on the Company’s condensed consolidated financial statements.

Accrued Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2019
Accrued Expenses
Accrued Expenses	3 . Accrued Expenses Accrued expenses consist of the following: June 30, December 31, 2019 2018 Clinical trials $ 1,892 $ 1,745 Professional fees 269 219 Payroll and related expenses 313 908 Accrued expenses $ 2,474 $ 2,872

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases
Leases	4. Leases In February 2016, the FASB issued ASU 2016-02, Leases, or ASU 2016-02. ASU 2016-02 requires a lessee to recognize on its balance sheet (for both finance and operating leases) a liability to make lease payments and a right-of-use asset representing its right to use the underlying asset for the lease term. ASU 2016-02 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The Company adopted ASU 2016-02 on January 1, 2019, on the effective date, and used the effective date as its date of initial application. As such, the Company did not adjust prior period amounts. The Company also elected to adopt the practical expedients upon transition, which permit companies to not reassess lease identification, classification, and initial direct costs under ASU 2016-02 for leases that commenced prior to the effective date. The Company has operating leases for real estate in the United States and does not have any finance leases. The Company’s leases may contain options to renew and extend lease terms and options to terminate leases early. Reflected in the right-of-use asset and lease liability on the Company’s consolidated balance sheets are the periods provided by renewal and extension options that the Company is reasonably certain to exercise, as well as the periods provided by termination options that the Company is reasonably certain to not exercise. The Company has existing leases that include variable lease and non-lease components that are not included in the right-of-use asset and lease liability and are reflected as an expense in the period incurred. Such payments primarily include common area maintenance charges and increases in rent payments that are driven by factors such as future changes in an index (e.g., the Consumer Price Index). In calculating the present value of future lease payments, the Company utilized its incremental borrowing rate based on the remaining lease term at the date of adoption. The Company has elected to account for each lease component and its associated non-lease components as a single lease component and has allocated all of the contract consideration across lease components only. This will potentially result in the initial and subsequent measurement of the balances of the right-of-use asset and lease liability for leases being greater than if the policy election was not applied. The Company has existing net leases in which the non-lease components (e.g. common area maintenance, maintenance, consumables, etc.) are paid separately from rent based on actual costs incurred and therefore are not included in the right-of-use asset and lease liability and are reflected as an expense in the period incurred. On January 1, 2019, the Company recorded a right-of-use asset of $1,755 and a lease liability of $1,720 on its consolidated balance sheets and reclassified a rent liability against the right-of-use asset of $35. As of June 30, 2019, a right-of-use asset of $1,398 and lease liability of $1,399 are reflected on the consolidated balance sheets. The Company recorded rent expense of $209 and $112, respectively, during the three months ended June 30, 2019 and 2018 and $418 and $292, respectively, for the six months ended June 30, 2019 and 2018. Future lease payments under non-cancelable leases as of June 30, 2019 are detailed as follows: Future Operating Lease Payments 2019 $ 421 2020 532 2021 434 2022 146 Total Lease Payments 1,533 Less: imputed interest (134) Total operating lease liabilities $ 1,399

Warrants

Warrants	6 Months Ended
	Jun. 30, 2019
Warrants
Warrants	5. Warrants As of June 30, 2019, outstanding warrants to purchase common stock consisted of the following: June 30, 2019 Number of Shares Exercise Date Exercisable Issuable Price Exercisable for Classification 1/23/2017 54,516 $ 0.01 Common Stock Equity 11/14/2017 2,758,094 $ 1.75 Common Stock Equity 2/5/2019 7,557,142 $ 1.95 Common Stock Equity 10,369,752 2017 Warrants The 2017 Warrants contain full ratchet anti-dilution protection provisions. Prior to January 1, 2019, the Company classified the 2017 Warrants as a liability on its consolidated balance sheet because each warrant represented a freestanding financial instrument that, due to the potential variable nature of the exercise price, is not considered to be indexed to the Company’s own shares. The warrant liability was initially recorded at fair value upon entering into the Private Placement and has been subsequently remeasured to fair value at each reporting date. Changes in the fair value of the warrant liability were recognized as gains (losses) in the Company’s consolidated statement of operations. On January 1, 2019, the Company adopted ASU 2017-11 and concluded that the 2017 Warrants now qualify for equity classification. The Company applied the guidance retrospectively to the 2017 Warrants by means of a cumulative-effect adjustment to its statement of financial position as of the beginning of the interim and annual period beginning January 1, 2019. The Company performed a final remeasurement of the warrant liability as of January 1, 2019 and reclassified $3,448 to additional paid in capital. The Company will recognize on a prospective basis the value of the effect of the down round feature in the warrant when it is triggered (i.e., when the exercise price is adjusted downward). This value is measured as the difference between (1) the financial instrument’s fair value (without the down round feature) using the pre-trigger exercise price and (2) the financial instrument’s fair value (with the down round feature) using the reduced exercise price. The value of the effect of the down round feature will be treated as a dividend and a reduction to income available to common shareholders in the basic EPS calculation. In connection with the 2019 Public Offering, when the 2017 Warrants were repriced from $6.085 to $1.75, the Company recorded a dividend of $359 during the six months ended June 30, 2019. 2019 Warrants On February 5, 2019, in connection with the 2019 Public Offering, the Company issued immediately exercisable warrants (the “2019 Warrants”) to purchase 7,557,142 shares of common stock to investors. The 2019 Warrants have an exercise price of $1.95 per share and expire on February 5, 2026. The 2019 Warrants qualify for equity classification.

Common Stock

Common Stock	6 Months Ended
	Jun. 30, 2019
Common Stock
Common Stock	6. Common Stock Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are entitled to receive dividends, as may be declared by the board of directors, if any, subject to the preferential dividend rights of the preferred stockholders. Through June 30, 2019, no dividends have been declared. Public Offering of Common Stock — March 2018 On March 27, 2018, the Company completed a public offering whereby the Company issued 2,146,667 shares of its common stock at a price of $7.50 per share, which included 280,000 shares issued pursuant to the underwriters’ exercise of their option to purchase additional shares of common stock. The aggregate net proceeds received by the Company from the offering were approximately $14,796, net of underwriting discounts and commissions and estimated offering expenses payable by the Company. Public Offering of Common Stock — February 2019 On February 5, 2019, the Company completed the 2019 Public Offering whereby the Company issued 7,557,142 shares of its common stock at a price of $1.75 per share, which included 985,714 shares issued pursuant to the underwriters' exercise of their option to purchase additional shares of common stock, each share issued with a warrant to purchase one share of common stock. Each warrant has an exercise price of $1.95 per share with an exercise period expiring seven years from the date of issuance. The aggregate net proceeds received by the Company from the 2019 Public Offering were approximately $12,122, net of underwriting discounts and commissions and estimated offering expenses payable by the Company. Issuance of Common Stock under Distribution Agreement – April 2019 On September 7, 2018, the Company filed a Prospectus Supplement to register the offer and sale of shares of common stock having an aggregate offering price of up to $30,000 pursuant to the terms of a distribution agreement, or the Distribution Agreement, with Raymond James & Associates, Inc. During the six months ended June 30, 2019, the Company issued 688,763 shares under the Distribution Agreement, for net proceeds of $1,306.

Equity Incentive Plans

Equity Incentive Plans	6 Months Ended
	Jun. 30, 2019
Equity Incentive Plans
Equity Incentive Plans	7 . Equity Incentive Plans Equity Incentive Plans In September 2012, the Company adopted the 2012 Equity Incentive Plan, as amended (the “Plan”), which provides designated employees of the Company and its affiliates, certain consultants and advisors who perform services for the Company and its affiliates, and nonemployee members of the Board of Directors of the Company and its affiliates with the opportunity to receive grants of incentive stock options, nonqualified stock options and stock awards. As of June 30, 2019, there were 1,381,220 outstanding options issued under the 2012 Plan. On January 20, 2017, the Company’s stockholders approved the 2016 Equity Incentive Plan (the “2016 Plan). Beginning on January 1, 2018, the number of shares of common stock authorized for issuance pursuant to the 2016 Plan was increased each January 1 by an amount equal to four percent (4%) of the Company’s outstanding common stock as of the end of the immediately preceding calendar year or such other amount as determined by the compensation committee of the Company’s Board of Directors. During the three months ended June 30, 2019, the compensation committee of the board of directors authorized an additional 3,000,000 shares of Common Stock to be added to the shares authorized for issuance under the 2016 Plan. As of June 30, 2019, there were 2,462,038 outstanding options issued under the 2016 Plan. As of June 30, 2019, there were 2,515,477 shares available for grant under the Company's Equity Incentive Plans. A summary of activity under the Equity Plans is as follows: Weighted Average Weighted Aggregate Exercise Price Average Remaining Intrinsic Options Per Share Life in Years Value Outstanding at December 31, 2018 2,761,912 $ 11.30 8.01 $ — Granted 1,469,475 $ 1.48 Forfeited (172,425) $ 17.04 Outstanding at June 30, 2019 4,058,962 $ 7.50 8.38 $ 484 Options exercisable at June 30, 2019 1,887,567 $ 11.98 7.23 $ — Options vested and expected to vest at June 30, 2019 4,058,962 $ 7.50 8.38 $ 484 The grant date fair value of the options granted during the year ended December 31, 2018 and the six months ended June 30, 2019, was estimated at the date of grant using the Black-Scholes option valuation model. The expected life was estimated using the “simplified” method as defined by the Securities and Exchange Commission’s Staff Accounting Bulletin 107, Share-Based Payment. The expected volatility was based on the historical volatility of comparable public companies from a representative peer group selected based on industry and market capitalization data. The risk-free interest rate was based on the continuous rates provided by the U.S. Treasury with a term approximating the expected life of the option. The expected dividend yield was 0% because the Company does not expect to pay any dividends for the foreseeable future. The Company elected the straight-line attribution method in recognizing the grant date fair value of options issued over the requisite service periods of the awards, which are generally the vesting periods. The assumptions that the Company used to determine the grant-date fair value of stock options granted to employees and directors during the year ended December 31, 2018 and the six months ended June 30, 2019 were as follows, presented on a weighted average basis: Six Months Year Ended Ended June 30, December 31, 2019 2018 Expected volatility 66.94 % 66.94 % Weighted average risk-free interest rate 2.08 % 2.80 % Expected dividend yield 0.00 % 0.00 % Expected term (in years) 6.77 6.95 Stock options generally vest over a three or four year period, as determined by the Compensation Committee of the Board of Directors at the time of grant. The options expire ten years from the grant date. As of June 30, 2019, there was approximately $4,940 of unrecognized compensation cost related to non-vested stock options, which is expected to be recognized over a remaining weighted-average period of approximately 2.16 years. The Company recognized stock-based compensation expense related to the issuance of stock option awards to employees and non-employees in the condensed consolidated statements of operations and comprehensive loss as follows: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Research and development $ 179 $ 162 $ 355 $ 279 General and administrative 720 722 1,491 1,333 Total $ 899 $ 884 $ 1,846 $ 1,612

Net Loss Per Share

Net Loss Per Share	6 Months Ended
	Jun. 30, 2019
Net Loss Per Share
Net Loss Per Share	8. Net Loss Per Share Basic and diluted net loss per share for the three and six months ended June 30, 2019 and 2018 was calculated as follows (in thousands except share and per share amounts): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Numerator: Net loss $ (8,366) $ (7,364) $ (16,969) $ (17,986) Dividend attributable to down round feature of warrants — — (359) — Net loss attributable to common stockholders for basic and diluted loss per share $ (8,366) $ (7,364) $ (17,328) $ (17,986) Denominator: Weighted average number of common shares outstanding – basic and diluted 22,906,025 14,691,890 21,081,869 13,576,850 Net loss per share attributable to common stockholders – basic and diluted $ (0.37) $ (0.50) $ (0.82) $ (1.32) The Company’s potentially dilutive securities include stock options and warrants. These securities were excluded from the computations of diluted net loss per share for the three and six months ended June 30, 2019 and 2018, as the effect would be to reduce the net loss per share. The following table includes the potential shares of common stock, presented based on amounts outstanding at each period end, that were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Options to purchase common stock 4,058,962 2,650,455 4,058,962 2,650,455 Warrants to purchase common stock 10,369,752 2,812,610 10,369,752 2,812,610 14,428,714 5,463,065 14,428,714 5,463,065

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies
Commitments and Contingencies	9 . Commitments and Contingencies Manufacturing Agreements —The Company is party to manufacturing agreements with vendors to manufacture TRX518 and DKN-01, its lead product candidates, for use in clinical trials. As of June 30, 2019, noncancelable commitments under these agreements totaled $471. License and Service Agreement —On January 3, 2011, the Company entered into a license agreement with Eli Lilly and Company (“Lilly”) to grant a license to the Company for certain intellectual property rights relating to pharmaceutically active compounds that may be useful in the treatment of bone healing, cancer and, potentially, other medical conditions. The Company previously issued 9,000,000 shares of Series A Stock to Lilly in consideration for the grant of the license. As defined in the license agreement, the Company would be required to pay royalties to Lilly based upon a percentage in the low single digits of net sales of developed products, if and when achieved. However, there can be no assurance that clinical or commercialization success of developed products will occur, and no royalties have been paid or accrued through June 30, 2019. License Agreement —On May 28, 2015, the Company entered into a license agreement with Lonza Sales AG (“Lonza”), pursuant to which Lonza granted the Company a world-wide, non-exclusive license for certain intellectual property relating to a gene expression system for manufacturing DKN‑01. As defined in the license agreement, the Company would be required to pay royalties to Lonza based on a percentage in the low single digits of net sales of DKN‑01, if and when achieved. However, there can be no assurance that clinical or commercialization success will occur, and no royalties have been paid or accrued through June 30, 2019. Legal Proceedings —At each reporting date, the Company evaluates whether or not a potential loss amount or a potential range of loss is probable and reasonably estimable under the provisions of the authoritative guidance that addresses accounting for contingencies. The Company expenses as incurred the costs related to its legal proceedings. A patent covering the TRX518 antibody and its uses in methods of inducing or enhancing an immune response in a subject was granted in 2013 to the Company by the European Patent Office (EPO). Three notices of opposition to this patent were filed: two by major pharmaceutical companies and a third by an individual, possibly on behalf of a major pharmaceutical company. At the conclusion of the opposition proceedings before the Opposition Division of the EPO, the Opposition Division issued a decision indicating that the Company’s patent was maintained with modified claims that differ from the claims as originally granted. These narrowed claims cover the TRX518 antibody and uses of the TRX518 antibody in methods of inducing or enhancing an immune response in a subject. The Company has filed an appeal of the decision of the Opposition Division seeking to obtain broader claims that more closely reflect the claims as granted in the patent. The EPO Board of Appeal has not yet scheduled a date for the appeal hearing. In 2016, a patent covering the use of the TRX518 antibody in combination with a chemotherapeutic agent for treating cancer was granted to the Company by the EPO. In March 2017, notices of opposition to this patent were filed at the EPO by ten different entities, including several major pharmaceutical companies. Oral proceedings at the EPO took place on December 4 and 5, 2018. At the conclusion of the oral proceedings, the Opposition Division decided that the patent should be revoked in its entirety on the ground that the claims as granted contained added matter. Subsequently, the Opposition Division issued an interlocutory decision restating its conclusion that the claims as granted contained added matter and revoking the patent. The Company has filed an appeal of the decision of the Opposition Division seeking to obtain a reversal of the Opposition Division's decision on added matter. The EPO Board of Appeal has not yet scheduled a date for the appeal hearing. Indemnification Agreements —In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company is not aware of any claims under indemnification arrangements, and it has not accrued any liabilities related to such obligations in its condensed consolidated financial statements as of June 30, 2019 or December 31, 2018.

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2019
Related Party Transactions
Related Party Transactions	10. Related Party Transactions The Company has a license agreement with a stockholder (See Note 9). On February 5, 2019, the Company completed the 2019 Public Offering pursuant to which the Company issued 7,557,142 shares of its common stock at a price of $1.75 per share, which included 985,714 shares issued pursuant to the underwriters' exercise of their option to purchase additional shares of common stock, each share issued with a warrant to purchase one share of common stock. Each warrant has an exercise price of $1.95 per share with an exercise period expiring seven years from the date of issuance. The aggregate net proceeds received by the Company from the offering were approximately $12,122, net of underwriting discounts and commissions and estimated offering expenses payable by the Company. HealthCare Ventures IX, L.P. purchased common stock and warrants in the 2019 Public Offering on the same terms and conditions as the other Purchasers. Three of the Company’s directors and executive officers are affiliated with HealthCare Ventures IX, L.P. and its affiliates.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2019
Subsequent Events
Subsequent Events	11. Subsequent Events Lincoln Park Purchase Agreements On July 10, 2019, the Company entered into a Commitment Purchase Agreement and a Registration Rights Agreement with Lincoln Park, pursuant to which the Company has the right to sell to Lincoln Park up to $20,000 in shares of its Common Stock, $0.001 par value per share, subject to certain limitations and conditions set forth in the Commitment Purchase Agreement. As consideration for Lincoln Park's commitment to purchase shares of Common Stock pursuant to the Commitment Purchase Agreement, the Company issued to Lincoln Park 330,000 shares of Common Stock. The Company will not receive any cash proceeds from the issuance of such shares. On July 11, 2019, the Company entered into a Registered Offering Purchase Agreement and together with the Commitment Purchase Agreement, under which the Company agreed to sell to Lincoln Park, and Lincoln Park agreed to purchase 571,429 shares of its Common Stock, at a price of $1.75 per share for an aggregate purchase price of $1,000, pursuant to the Company’s effective shelf registration statement on Form S-3 (Registration No. 333-223419), including the prospectus supplement thereto dated July 11, 2019. Issuance of Common Stock under Distribution Agreement – July 2019 In July 2019, the Company issued 188,306 shares under its Distribution Agreement with Raymond James & Associates, Inc., for net proceeds of $347.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2019
Summary of Significant Accounting Policies
Principles of Consolidation	Principles of Consolidation The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany accounts and transactions are eliminated upon consolidation.
Use of Estimates	Use of Estimates The presentation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Research and development incentive income and receivable	Research and development incentive income and receivable The Company recognizes other income from Australian research and development incentives when there is reasonable assurance that the income will be received, the relevant expenditure has been incurred, and the consideration can be reliably measured. The research and development incentive is one of the key elements of the Australian Government’s support for Australia’s innovation system and is supported by legislative law primarily in the form of the Australian Income Tax Assessment Act 1997, as long as eligibility criteria are met. Management has assessed the Company’s research and development activities and expenditures to determine which activities and expenditures are likely to be eligible under the research and development incentive regime described above. At each period end, management estimates the refundable tax offset available to the Company based on available information at the time. This estimate is also reviewed by external tax advisors on an annual basis. Under the program, a percentage of eligible research and development expenses incurred by the Company through its subsidiary in Australia are reimbursed. The percentage was 43.5% for the year ended December 31, 2018 and for the three and six months ended June 30, 2019. The research and development incentive receivable represents an amount due in connection with the above program. The Company has recorded a research and development incentive receivable of $971 and $836 as of June 30, 2019 and December 31, 2018, respectively, in the condensed consolidated balance sheets and other income from Australian research and development incentives of $61 and $243, respectively, for the three months ended June 30, 2019 and 2018 and $136 and $889 for the six months ended June 30, 2019 and 2018, respectively, in the condensed consolidated statements of operations related to refundable research and development incentive program payments in Australia. The following table shows the change in the research and development incentive receivable from December 31, 2017 to June 30, 2019 (in thousands): Balance at December 31, 2017 $ 1,744 Australian research and development incentive income 756 Cash received for 2016 eligible overseas research and development expenses (740) Cash received for 2017 eligible expenses (793) Foreign currency translation (131) Balance at December 31, 2018 836 Australian research and development incentive income 136 Foreign currency translation (1) Balance at June 30, 2019 $ 971
Foreign Currency Translation	Foreign Currency Translation The financial statements of the Company’s Australian subsidiary are measured using the local currency as the functional currency. Assets and liabilities of this subsidiary are translated into U.S. dollars at an exchange rate as of the consolidated balance sheet date. Equity is translated at historical exchange rates. Revenues and expenses are translated into U.S. dollars at average rates of exchange in effect during the year. The resulting cumulative translation adjustments have been recorded as a separate component of stockholders’ equity. Realized foreign currency transaction gains and losses are included in the results of operations.
Other Assets	Other Assets Other assets as of June 30, 2019 and December 31, 2018 included $1,344 and $1,380, respectively, of deposits made by the Company with certain service providers that are to be applied to future payments due under the service agreements or returned to the Company if not utilized. In addition, as of June 30, 2019 and December 31, 2018 other assets included $181 and $162 of deferred issuance costs, respectively.
Warrants	Warrants On January 1, 2019, the Company adopted ASU No. 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), and Derivatives and Hedging (Topic 815) ("ASU 2017-11"), which changes the classification analysis of certain equity-linked financial instruments (or embedded features) with down round features. The amendments require entities that present earnings per share ("EPS") in accordance with Topic 260 to recognize the effect of the down round feature when triggered with the effect treated as a dividend and as a reduction of income available to common shareholders in basic EPS. The Company concluded that the common stock warrants (the “2017 Warrants”) issued in connection with the private placement of common stock completed in November 2017 (the “Private Placement”), qualify for equity classification. The adoption guidance of ASU 2017-11 provides for a modified retrospective adoption. The Company applied the guidance retrospectively to the 2017 Warrants by means of a cumulative-effect adjustment to its statement of financial position as of the beginning of the interim and annual period beginning January 1, 2019. The Company performed a final remeasurement of the warrant liability as of January 1, 2019 and reclassified $3,448 to additional paid-in capital. The Company will recognize on a prospective basis the value of the effect of the down round feature in the 2017 Warrants when it is triggered (i.e., when the exercise price is adjusted downward). This value is measured as the difference between (1) the financial instrument’s fair value (without the down round feature) using the pre-trigger exercise price and (2) the financial instrument’s fair value (with the down round feature) using the reduced exercise price. The value of the effect of the down round feature will be treated as a dividend and a reduction to income available to common shareholders in the basic EPS calculation. In connection with the public offering, completed in February 2019 (the “2019 Public Offering”), when the 2017 Warrants were repriced from $6.085 to $1.75 as a result of a down round, the Company recorded a dividend of $359 during the six months ended June 30, 2019.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Certain assets and liabilities are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: · Level 1—Quoted prices in active markets for identical assets or liabilities. · Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. · Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. During the periods presented, the Company has not changed the manner in which it values assets and liabilities that are measured at fair value using Level 3 inputs. The Company recognizes transfers between levels of the fair value hierarchy as of the end of the reporting period. There were no transfers within the hierarchy during the three and six months ended June 30, 2019 and the year ended December 31, 2018. A summary of the assets and liabilities carried at fair value in accordance with the hierarchy defined above is as follows (in thousands): Total Level 1 Level 2 Level 3 June 30, 2019 Assets: Cash equivalents $ 15,747 $ 15,747 $ — $ — Total assets $ 15,747 $ 15,747 $ — $ — December 31, 2018 Assets: Cash equivalents $ 16,284 $ 16,284 $ — $ — Total assets $ 16,284 $ 16,284 $ — $ — Liabilities: Warrant liability $ 3,448 $ — $ — $ 3,448 Total liabilities $ 3,448 $ — $ — $ 3,448 Cash equivalents of $15,747 and $16,284 as of June 30, 2019 and December 31, 2018, respectively, consisted of overnight investments and money market funds and are classified within Level 1 of the fair value hierarchy because they are valued using quoted market prices in active markets. The carrying value of the research and development incentive receivable, accounts payable and accrued liabilities approximate their fair value due to the short-term nature of these assets and liabilities. A roll-forward of the recurring fair value measurements of the warrant liability categorized with Level 3 inputs is as follows (in thousands): Warrant Liability Balance—December 31, 2017 $ 11,862 Change in fair value 4,851 Balance—March 31, 2018 16,713 Exercise of warrants (1,130) Change in Fair value 662 Balance—June 30, 2018 16,245 Change in Fair value (1,793) Balance—September 30, 2018 14,452 Change in Fair value (11,004) Balance—December 31, 2018 3,448 Final remeasurement and reclassification of 2017 Warrants to equity in connection with the adoption of ASU 2017-11 (3,448) Balance—January 1, 2019 $ — The warrant liability in the table above is composed of the fair value of the 2017 Warrants that the Company issued in connection with the Private Placement. The fair value of the warrant liability was determined based on significant inputs not observable in the market, which represents a Level 3 measurement within the fair value hierarchy. The Company utilized a Monte Carlo simulation, which is a statistical method used to generate a defined number of share price paths to develop a reasonable estimate of the range of the future expected share prices, to value the warrant liability. The Monte Carlo simulation incorporated assumptions and estimates to value the warrant liability. Estimates and assumptions impacting the fair value measurement included the estimated probability of adjusting the exercise price of the warrants, the number of shares for which the warrants will be exercisable, the remaining contractual term of the warrants, the risk-free interest rate, the expected dividend yield, and the expected volatility of the price of the underlying common shares. The Company historically had been a private company and lacks company-specific historical and implied volatility information of its shares. Therefore, it estimated its expected share volatility based on the historical volatility of publicly traded peer companies for a term equal to the remaining contractual term of the warrants. The risk-free interest rate was determined by reference to the U.S. Treasury yield curve for time periods approximately equal to the remaining contractual term of the warrants. The Company estimated a 0% expected dividend yield based on the fact that the Company has never paid or declared dividends and does not intend to do so in the foreseeable future.
Leases	Leases In February 2016, the FASB issued ASU 2016-02, Leases, or ASU 2016-02, to enhance the transparency and comparability of financial reporting related to leasing arrangements. The Company adopted ASU 2016-02 on January 1, 2019, or the effective date, and used the effective date as its date of initial application. At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the unique facts and circumstances present. Most leases with a term greater than one year are recognized on the balance sheet as right-of-use assets, lease liabilities and, if applicable, long-term lease liabilities. The Company has elected not to recognize on the balance sheet leases with terms of one year or less. Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of lease payments over the expected remaining lease term. The Company has determined that the rate implicit in the lease is not determinable and the Company does not have borrowings with similar terms and collateral. Therefore, the Company considered a variety of factors, including observable debt yields from comparable companies and the volatility in the debt market for securities with similar terms, in determining that 8% was reasonable to use as the incremental borrowing rate for purposes of the calculation of lease liabilities. In accordance with the guidance in ASU 2016-02, components of a lease should be split into three categories: lease components (e.g. land, building, etc.), non-lease components (e.g. common area maintenance, maintenance, consumables, etc.), and non-components (e.g. property taxes, insurance, etc.). Then the fixed and in-substance fixed contract consideration (including any related to non-components) must be allocated based on fair values to the lease components and non-lease components. Although separation of lease and non-lease components is required, certain practical expedients are available. Entities may elect the practical expedient to not separate lease and non-lease components. Rather, they would account for each lease component and the related non-lease component together as a single component. The Company has elected to account for the lease and non-lease components of each of its operating leases as a single lease component and allocate all of the contract consideration to the lease component only. The lease component results in an operating right-of-use asset being recorded on the consolidated balance sheets and amortized such that lease expense is recorded on a straight line basis over the term of the lease.
Net Loss per Share	Net Loss per Share Basic net loss per share is computed using the weighted average number of common shares outstanding during the period. Diluted net loss per share is computed using the weighted average number of common shares outstanding during the period and, if dilutive, the weighted average number of potential shares of common stock, including the assumed exercise of stock options and warrants.
Warrant Liability	Warrant Liability In connection with entering into the Private Placement, the Company issued the 2017 Warrants with each share of common stock sold in the Private Placement. The Company classified the 2017 Warrants as a liability on its consolidated balance sheet prior to January 1, 2019, because each warrant represented a freestanding financial instrument that is not indexed to the Company’s own shares. The warrant liability was initially recorded at fair value upon entering into the Private Placement agreement and was subsequently remeasured to fair value at each reporting date. Changes in the fair value of the warrant liability were recognized as gains (losses) in the condensed consolidated statement of operations through the year ended December 31, 2018.
Subsequent Events	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 or to identify matters that require additional disclosure. Subsequent events have been evaluated as required.
Recent Accounting Pronouncements	Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board, or FASB, and are early adopted by the Company or adopted as of the specified effective date. In June 2018, the FASB issued ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting, which is intended to simplify the accounting for share-based payments to nonemployees by aligning it with the accounting for share-based payments to employees, with certain exceptions. The Company adopted this standard effective January 1, 2019, which had no impact on the Company’s condensed consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2019
Summary of Significant Accounting Policies
Schedule of change in the research and development incentive receivable	The following table shows the change in the research and development incentive receivable from December 31, 2017 to June 30, 2019 (in thousands): Balance at December 31, 2017 $ 1,744 Australian research and development incentive income 756 Cash received for 2016 eligible overseas research and development expenses (740) Cash received for 2017 eligible expenses (793) Foreign currency translation (131) Balance at December 31, 2018 836 Australian research and development incentive income 136 Foreign currency translation (1) Balance at June 30, 2019 $ 971
Summary of assets and liabilities carried at fair value in accordance with the hierarchy	A summary of the assets and liabilities carried at fair value in accordance with the hierarchy defined above is as follows (in thousands): Total Level 1 Level 2 Level 3 June 30, 2019 Assets: Cash equivalents $ 15,747 $ 15,747 $ — $ — Total assets $ 15,747 $ 15,747 $ — $ — December 31, 2018 Assets: Cash equivalents $ 16,284 $ 16,284 $ — $ — Total assets $ 16,284 $ 16,284 $ — $ — Liabilities: Warrant liability $ 3,448 $ — $ — $ 3,448 Total liabilities $ 3,448 $ — $ — $ 3,448
Schedule of the recurring fair value measurements of the warrant derivative liability categorized with Level 3 inputs	A roll-forward of the recurring fair value measurements of the warrant liability categorized with Level 3 inputs is as follows (in thousands): Warrant Liability Balance—December 31, 2017 $ 11,862 Change in fair value 4,851 Balance—March 31, 2018 16,713 Exercise of warrants (1,130) Change in Fair value 662 Balance—June 30, 2018 16,245 Change in Fair value (1,793) Balance—September 30, 2018 14,452 Change in Fair value (11,004) Balance—December 31, 2018 3,448 Final remeasurement and reclassification of 2017 Warrants to equity in connection with the adoption of ASU 2017-11 (3,448) Balance—January 1, 2019 $ —

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2019
Accrued Expenses
Schedule of accrued expenses	June 30, December 31, 2019 2018 Clinical trials $ 1,892 $ 1,745 Professional fees 269 219 Payroll and related expenses 313 908 Accrued expenses $ 2,474 $ 2,872

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases
Schedule of future minimum lease payments	Future Operating Lease Payments 2019 $ 421 2020 532 2021 434 2022 146 Total Lease Payments 1,533 Less: imputed interest (134) Total operating lease liabilities $ 1,399

Warrants (Tables)

Warrants (Tables)	6 Months Ended
	Jun. 30, 2019
Warrants
Schedule of warrants	June 30, 2019 Number of Shares Exercise Date Exercisable Issuable Price Exercisable for Classification 1/23/2017 54,516 $ 0.01 Common Stock Equity 11/14/2017 2,758,094 $ 1.75 Common Stock Equity 2/5/2019 7,557,142 $ 1.95 Common Stock Equity 10,369,752

Equity Incentive Plans (Tables)

Equity Incentive Plans (Tables)	6 Months Ended
	Jun. 30, 2019
Equity Incentive Plans
Summary of stock option activity under the Company's Equity Incentive Plans	Weighted Average Weighted Aggregate Exercise Price Average Remaining Intrinsic Options Per Share Life in Years Value Outstanding at December 31, 2018 2,761,912 $ 11.30 8.01 $ — Granted 1,469,475 $ 1.48 Forfeited (172,425) $ 17.04 Outstanding at June 30, 2019 4,058,962 $ 7.50 8.38 $ 484 Options exercisable at June 30, 2019 1,887,567 $ 11.98 7.23 $ — Options vested and expected to vest at June 30, 2019 4,058,962 $ 7.50 8.38 $ 484
Schedule of assumptions used to determine grant-date fair value of stock options	Six Months Year Ended Ended June 30, December 31, 2019 2018 Expected volatility 66.94 % 66.94 % Weighted average risk-free interest rate 2.08 % 2.80 % Expected dividend yield 0.00 % 0.00 % Expected term (in years) 6.77 6.95
Schedule of stock-based compensation expense classified in the consolidated statements of operations	Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Research and development $ 179 $ 162 $ 355 $ 279 General and administrative 720 722 1,491 1,333 Total $ 899 $ 884 $ 1,846 $ 1,612

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	6 Months Ended
	Jun. 30, 2019
Net Loss Per Share
Schedule of basic and diluted net loss per share	Basic and diluted net loss per share for the three and six months ended June 30, 2019 and 2018 was calculated as follows (in thousands except share and per share amounts): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Numerator: Net loss $ (8,366) $ (7,364) $ (16,969) $ (17,986) Dividend attributable to down round feature of warrants — — (359) — Net loss attributable to common stockholders for basic and diluted loss per share $ (8,366) $ (7,364) $ (17,328) $ (17,986) Denominator: Weighted average number of common shares outstanding – basic and diluted 22,906,025 14,691,890 21,081,869 13,576,850 Net loss per share attributable to common stockholders – basic and diluted $ (0.37) $ (0.50) $ (0.82) $ (1.32)
Schedule of potentially anti-dilutive securities excluded from calculation of diluted net loss per share	Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Options to purchase common stock 4,058,962 2,650,455 4,058,962 2,650,455 Warrants to purchase common stock 10,369,752 2,812,610 10,369,752 2,812,610 14,428,714 5,463,065 14,428,714 5,463,065

Nature of Business, Basis of _2

Nature of Business, Basis of Presentation and Liquidity - Liquidity (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 11, 2019	Sep. 07, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jul. 10, 2019	Dec. 31, 2018
Liquidity and going concern
Accumulated deficit			$ 179,237		$ 179,237			$ 153,535
Net loss			8,366	$ 7,364	16,969	$ 17,986
Cash and cash equivalents			$ 15,747		$ 15,747			$ 16,284
Common stock, par value (in dollars per share)			$ 0.001		$ 0.001			$ 0.001
Purchase price					$ 12,122	14,796
Research and development incentive receivable			$ 836		836			$ 836
Subsequent Events
Liquidity and going concern
Commons stock value maximum right to sell							$ 20,000
Common stock, par value (in dollars per share)							$ 0.001
Number of shares agreed to purchase (in shares)	571,429
Common share value (in dollars per share)	$ 1.75
Purchase price	$ 1,000
Common Stock
Liquidity and going concern
Purchase price		$ 30,000			$ 7	$ 3

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Research and development incentive income and receivable
Research and development expenses reimbursed (as a percent)	43.50%		43.50%		43.50%
Research and development incentive income and receivable
Balance at the beginning of the period			$ 836	$ 1,744	$ 1,744
Australian research and development incentive income	$ 61	$ 243	136	$ 889	756
Cash received for 2016 eligible overseas research and development expenses					(740)
Cash receiver for eligible expenses					(793)
Foreign currency translation			(1)		(131)
Balance at the end of the period	971		971		836
Other Assets
Other assets	1,344		1,344		1,380
Deferred issuance costs	$ 181		$ 181		$ 162

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Warrants and Fair Value of Financial Instruments (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 01, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Dec. 31, 2018	Feb. 05, 2019	Feb. 04, 2019
Assets:
Cash equivalents		$ 16,284				$ 15,747	$ 16,284
Total assets		16,284				15,747	16,284
Liabilities:
Warrant liability		3,448					3,448
Total liabilities		3,448					$ 3,448
Warrants
Final remeasurement and reclassification of 2017 Warrants to equity in connection with the adoption of ASU 2017-11						3,447
Fair value measurements of the warrant liability
Final remeasurement and reclassification of 2017 Warrants to equity in connection with the adoption of ASU 2017-11						$ 3,447
Expected dividend yield (as a percentage)						0.00%	0.00%
Leases
Leases, discount rate						8.00%
Warrant Liability | Public Offering
Warrants
Record the value of the effect of the down round feature as a dividend						$ 359
Warrant Liability | Private Placement
Warrants
Final remeasurement and reclassification of 2017 Warrants to equity in connection with the adoption of ASU 2017-11	$ 3,448
Fair value measurements of the warrant liability
Final remeasurement and reclassification of 2017 Warrants to equity in connection with the adoption of ASU 2017-11	3,448
Minimum | Warrant Liability | Public Offering
Warrants
Exercise price of warrant									$ 6.085
Maximum | Warrant Liability | Public Offering
Warrants
Exercise price of warrant								$ 1.75
Level 1
Assets:
Cash equivalents		16,284				15,747	$ 16,284
Total assets		16,284				15,747	16,284
Level 3
Liabilities:
Warrant liability		3,448					3,448
Total liabilities		3,448					3,448
Recurring | Warrant Liability
Warrants
Final remeasurement and reclassification of 2017 Warrants to equity in connection with the adoption of ASU 2017-11	(3,448)
Fair value measurements of the warrant liability
Beginning Balance	3,448	14,452	$ 16,245	$ 16,713	$ 11,862	$ 3,448	11,862
Change in fair value		(11,004)	(1,793)	662	4,851
Exercise of warrants				(1,130)
Final remeasurement and reclassification of 2017 Warrants to equity in connection with the adoption of ASU 2017-11	$ (3,448)
Ending Balance		$ 3,448	$ 14,452	$ 16,245	$ 16,713		$ 3,448

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Accrued Expenses
Clinical trials	$ 1,892	$ 1,745
Professional fees	269	219
Payroll and related expenses	313	908
Accrued expenses	$ 2,474	$ 2,872

Leases - (Details)

Leases - (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Leases
Right of use asset, net	$ 1,755	$ 1,398		$ 1,398
Lease liability	1,720	1,399		1,399
Rent expense		$ 209	$ 112	$ 418	$ 292
Reclassified rent liability against the right-of-use asset	$ 35

Leases - Future minimum lease p

Leases - Future minimum lease payments (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019
Leases
2019	$ 421
2020	532
2021	434
2022	146
Total Lease Payments	1,533
Imputed interest	(134)
Total operating lease liabilities	$ 1,399	$ 1,720

Warrants - (Details)

Warrants - (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 01, 2019	Jun. 30, 2019	May 02, 2019	Feb. 05, 2019	Feb. 04, 2019	Nov. 14, 2017	Jan. 23, 2017
Warrants
Number of Shares Issuable		10,369,752
Final remeasurement and reclassification of 2017 Warrants to equity in connection with the adoption of ASU 2017-11		$ 3,447
Common Stock | Equity
Warrants
Number of Shares Issuable			7,557,142			2,758,094	54,516
Exercise price of warrant			$ 1.95			$ 1.750	$ 0.01
Common Stock | Public Offering | Warrants expires on 2026
Warrants
Number of Shares Issuable				7,557,142
Warrant Liability
Warrants
Final remeasurement and reclassification of 2017 Warrants to equity in connection with the adoption of ASU 2017-11	$ 3,448
Warrant Liability | Public Offering
Warrants
Exercise price of warrant				$ 1.95
Recorded a dividend for warrants		$ 359
Warrant Liability | Public Offering | Warrants expires on 2026
Warrants
Exercise price of warrant				1.95
Warrant Liability | Minimum | Public Offering
Warrants
Exercise price of warrant					$ 6.085
Warrant Liability | Maximum | Public Offering
Warrants
Exercise price of warrant				$ 1.75

Common Stock (Details)

Common Stock (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)item
Common Stock
Number of votes each common share is entitled to | item	1
Dividend declared | $	$ 0

Common Stock - Public Offering

Common Stock - Public Offering of Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Feb. 05, 2019	Sep. 07, 2018	Mar. 27, 2018	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018
Purchase price					$ 12,122	$ 14,796
Issuance of common stock					688,763
Issuance of common stock, net proceeds				$ 1,306	$ 1,306
Common Stock
Issuance of stock (in shares)					7,557,142	2,146,667
Purchase price		$ 30,000			$ 7	$ 3
Issuance of common stock				688,763	688,763
Issuance of common stock, net proceeds				$ 1	$ 1
Common Stock | Public Offering
Issuance of stock (in shares)	7,557,142		2,146,667
Price per common stock (in dollars per share)	$ 1.75		$ 7.50
Proceeds from the issuance of common stock	$ 12,122		$ 14,796
Common Stock | Over-Allotment Option
Issuance of stock (in shares)	985,714		280,000
Warrant Liability | Public Offering
Exercise price of warrant	$ 1.95
Exercise Expiring Period	7 years

Equity Incentive Plan - Equity

Equity Incentive Plan - Equity Incentive Plans (Details) - shares	Jan. 20, 2017	Jun. 30, 2019	Jun. 30, 2019
Stock-Based Compensation
Shares granted under equity incentive plan			1,469,475
2012 Plan
Stock-Based Compensation
Number of options issued under the plan			1,381,220
2016 Plan
Stock-Based Compensation
Number of options issued under the plan			2,462,038
Shares granted under equity incentive plan			2,515,477
2016 Plan | Common Stock
Stock-Based Compensation
Additional shares issuable		3,000,000
Annual increase in authorized shares (as a percent)	4.00%

Equity Incentive Plan - Stock o

Equity Incentive Plan - Stock options (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Options
Outstanding balance at the beginning of the period (in shares)			2,761,912
Granted (in shares)			1,469,475
Forfeited (in shares)			(172,425)
Outstanding balance at the end of the period (in shares)	4,058,962		4,058,962		2,761,912
Options exercisable at the end of the period (in shares)	1,887,567		1,887,567
Options vested and expected to vest at end of period (in shares)	4,058,962		4,058,962
Weighted Average Exercise Price Per Share
Outstanding balance at the beginning of the period (in dollars per share)			$ 11.30
Granted (in dollars per share)			1.48
Forfeited (in dollars per share)			17.04
Outstanding balance at the end of the period (in dollars per share)	$ 7.50		7.50		$ 11.30
Exercisable at the end of the period (in dollars per share)	11.98		11.98
Options vested and expected to vest at end of the period (in dollars per share)	$ 7.50		$ 7.50
Weighted Average Remaining Life in Years
Outstanding balance			8 years 4 months 17 days		8 years 4 days
Options exercisable at end of period			7 years 2 months 23 days
Options vested and expected to vest at end of the period			8 years 4 months 17 days
Aggregate Intrinsic Value
Outstanding balance	$ 484		$ 484
Options vested and expected to vest at end of the period	484		484
Stock-based compensation expense	899	$ 884	$ 1,846	$ 1,612
Assumptions used to determine grant-date fair value
Expected Volatility			66.94%		66.94%
Weighted average risk-free interest rate			2.08%		2.80%
Expected dividend yield (as a percentage)			0.00%		0.00%
Expected term (in years)			6 years 9 months 7 days		6 years 11 months 12 days
Expiration period			10 years
Compensation cost related to the non-vested awards not yet recognized	4,940		$ 4,940
Weighted average period for recognition of compensation cost			2 years 1 month 28 days
Research and development
Aggregate Intrinsic Value
Stock-based compensation expense	179	162	$ 355	279
General and administrative
Aggregate Intrinsic Value
Stock-based compensation expense	$ 720	$ 722	$ 1,491	$ 1,333
Maximum
Assumptions used to determine grant-date fair value
Vesting period			4 years
Minimum
Assumptions used to determine grant-date fair value
Vesting period			3 years

Net Loss Per Share - Basic and

Net Loss Per Share - Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator:
Net loss	$ (8,366)	$ (7,364)	$ (16,969)	$ (17,986)
Dividend attributable to down round feature of warrants			(359)
Net loss attributable to common stockholders for basic and diluted loss per share	$ (8,366)	$ (7,364)	$ (17,328)	$ (17,986)
Denominator:
Weighted average number of common shares outstanding - basic and diluted (in shares)	22,906,025	14,691,890	21,081,869	13,576,850
Net loss per share attributable to common stockholders - basic and diluted (in dollars per share)	$ (0.37)	$ (0.50)	$ (0.82)	$ (1.32)

Net Loss Per Share - Antidiluti

Net Loss Per Share - Antidilutive (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	14,428,714	5,463,065	14,428,714	5,463,065
Options to purchase common stock
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	4,058,962	2,650,455	4,058,962	2,650,455
Warrants to purchase common stock
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	10,369,752	2,812,610	10,369,752	2,812,610

Commitments and Contingencies -

Commitments and Contingencies - Manufacturing, License and Other Agreements (Details) - USD ($) $ in Thousands	Jan. 03, 2011	Jun. 30, 2019
TRX518 and DKN-01
Commitments and Contingencies
Noncancelable commitments		$ 471
License and service agreements
Commitments and Contingencies
Paid or accrued royalties		0
License and service agreements | Preferred Class A
Commitments and Contingencies
Issuance of stock in consideration for license (in shares)	9,000,000
Licensing agreements
Commitments and Contingencies
Paid or accrued royalties		$ 0

Commitments and Contingencies_2

Commitments and Contingencies - Legal Proceedings (Details)	1 Months Ended	6 Months Ended
	Mar. 31, 2017item	Jun. 30, 2019companyindividualitem
TRX518
Loss Contingencies
Number of notices of opposition filed		3
Number of major companies that filed notices of opposition | company		2
Number of individuals that filed notices of opposition | individual		1
TRX518 and Chemotherapeutic
Loss Contingencies
Number of notices of opposition filed	10

Related Party Transactions (Det

Related Party Transactions (Details) $ / shares in Units, $ in Thousands	Feb. 05, 2019USD ($)$ / sharesshares	Mar. 27, 2018shares	Jun. 30, 2019shares	Jun. 30, 2018shares	Nov. 14, 2017director
Public Offering
Related Party Transactions
Number of warrants issued per common stock	1
Public Offering | HCV IX and Eli Lilly
Related Party Transactions
Number of affiliated directors and executive officers | director					3
Common Stock
Related Party Transactions
Issuance of stock (in shares)			7,557,142	2,146,667
Common Stock | Public Offering
Related Party Transactions
Issuance of stock (in shares)	7,557,142
Price per common stock (in dollars per share) | $ / shares	$ 1.75
Proceeds from the issuance of common stock | $	$ 12,122
Common Stock | Over-Allotment Option
Related Party Transactions
Issuance of stock (in shares)	985,714	280,000
Warrant Liability | Public Offering
Related Party Transactions
Exercise price of warrant | $ / shares	$ 1.95
Warrant expiring period	7 years

Subsequent Events - (Details)

Subsequent Events - (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 11, 2019	Jul. 31, 2019	Jun. 30, 2019	Jun. 30, 2018	Jul. 10, 2019	Dec. 31, 2018
Subsequent Events
Common stock, par value (in dollars per share)			$ 0.001			$ 0.001
Purchase price			$ 12,122	$ 14,796
Subsequent Events
Subsequent Events
Commons stock value maximum right to sell					$ 20,000
Common stock, par value (in dollars per share)					$ 0.001
Number of shares agreed to purchase (in shares)	571,429
Common share value (in dollars per share)	$ 1.75
Purchase price	$ 1,000
Subsequent Events | Lincoln Park Purchase Agreements
Subsequent Events
Commons stock value maximum right to sell					$ 20,000
Common stock, par value (in dollars per share)					$ 0.001
Number of shares agreed to purchase (in shares)	571,429				330,000
Common share value (in dollars per share)	$ 1.75
Purchase price	$ 1,000
Subsequent Events | Distribution Agreement - July 2019
Subsequent Events
Shares issued (in shares)		188,306
Proceeds from the issuance of common stock		$ 347