SELLAS Life Sciences (SLS) 10-K 13 Apr 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Apr. 06, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	SLS
Entity Registrant Name	SELLAS LIFE SCIENCES GROUP, INC.
Entity Central Index Key	1,390,478
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		6,572,542
Entity Public Float			$ 21,640,272

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 2,319	$ 5,962
Restricted cash and cash equivalents	10,431	85
Prepaid expenses and other current assets	337	332
Total current assets	13,087	6,379
Intangible assets	17,600
Goodwill	1,914
Deposits and other assets	925	41
Total assets	33,526	6,420
Current liabilities:
Current portion of long-term debt	8,377
Current portion of convertible debt		1,709
Accounts payable	11,691
Accrued expenses and other current liabilities	3,201	4,049
Litigation settlement payable	1,300
Total current liabilities	24,569	5,758
Deferred tax liability	1,673
Warrant liability	1,309
Contingent purchase price consideration	1,294
Long-term debt, net of current portion	2,611
Convertible debt, net of current portion		5,659
Total liabilities	31,456	11,417
Commitments and contingencies
Stockholders' equity (deficit):
Preferred stock, $0.0001 par value; 5,000,000 shares authorized; no shares issued and outstanding
Common stock, $0.0001 par value; 350,000,000 shares authorized, 5,766,891 shares issued and outstanding at December 31, 2017; 1,268,489 shares issued and outstanding at December 31, 2016	1
Additional paid-in capital	56,254	25,434
Accumulated deficit	(54,185)	(30,431)
Total stockholders' equity (deficit)	2,070	(4,997)
Total liabilities and stockholders' equity (deficit)	$ 33,526	$ 6,420

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Preferred stock, par value (USD per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (USD per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	350,000,000	350,000,000
Common stock, shares issued	5,766,891	1,268,489
Common stock, shares outstanding	5,766,891	1,268,489

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Operating expenses:
Research and development	$ 6,067	$ 11,395
General and administrative	15,089	4,593
Severance costs	1,883
Total operating expenses and loss from operations	(23,039)	(15,988)
Interest expense, net	462	1,166
Other expense		526
Income tax expense	253	1
Net loss	(23,754)	(17,681)
Deemed dividend on conversion of 2015 Sely Note	(675)
Loss attributable to common stockholders	$ (24,429)	$ (17,681)
Basic and diluted loss per share to common stockholders	$ (10.44)	$ (18.66)
Weighted-average common shares outstanding, basic and diluted	2,340,368	947,401

CONSOLIDATED STATEMENT OF STOCK

CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings
Beginning balance at Dec. 31, 2015	$ (12,262)		$ 488	$ (12,750)
Beginning balance, shares at Dec. 31, 2015		879,994
Shares issued as partial consideration of MSK license fees	900		900
Shares issued as partial consideration of MSK license fees, shares		13,815
Shares issued pursuant to MSK license agreement	1,976		1,976
Shares issued pursuant to MSK license agreement, shares		41,181
Shares issued in cancellation of Clarendon license agreement	502		502
Shares issued in cancellation of Clarendon license agreement, shares		7,700
Shares issued upon conversion of 2016 convertible term note	15,411		15,411
Shares issued upon conversion of 2016 convertible term note, shares		236,705
Shares issued in cancellation of long term debt	5,803		5,803
Shares issued in cancellation of long term debt, shares		89,094
Stock-based compensation expense	354		354
Net loss	(17,681)			(17,681)
Ending balance at Dec. 31, 2016	(4,997)		25,434	(30,431)
Ending balance, shares at Dec. 31, 2016		1,268,489
Shares issued in connection with amendments to MSK license	388		388
Shares issued in connection with amendments to MSK license, shares		83,594
Shares issued upon conversion of 2016 convertible term note	1,294		1,294
Shares issued upon conversion of 2016 convertible term note, shares		330,551
Sale of common shares to related parties	6,007		6,007
Sale of common shares to related parties, shares		1,534,711
Shares issued in connection with settlement of related party payables	378		378
Shares issued in connection with settlement of related party payables, shares		96,662
Shares issued upon the acceleration of restricted stock units, shares		46,373
Shares issued upon cancellation of Equilibria restricted stock units, shares		58,208
Shares issued in connection with acquisition of Galena	12,487	$ 1	12,486
Shares issued in connection with acquisition of Galena, shares		1,588,605
Fair value of assumed options issued in connection with acquisition of Galena	32		32
Shares and common stock warrants issued upon conversion of 2015 Sely Note and accrued interest to Equilibria	6,739		6,739
Shares and common stock warrants issued upon conversion of 2015 Sely Note and accrued interest to Equilibria, shares		632,326
Deemed dividend associated with conversion of 2015 Sely Note and common stock warrant issuance to Equilibria	(675)		(675)
Shares issued to Equilibria for incentive fee payment in connection with the acquisition of Galena	941		941
Shares issued to Equilibria for incentive fee payment in connection with the acquisition of Galena, shares		119,672
Shares issued to MSK for anti-dilution provisions	61		61
Shares issued to MSK for anti-dilution provisions, shares		7,700
Stock-based compensation expense	3,169		3,169
Net loss	(23,754)			(23,754)
Ending balance at Dec. 31, 2017	$ 2,070	$ 1	$ 56,254	$ (54,185)
Ending balance, shares at Dec. 31, 2017		5,766,891

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net loss	$ (23,754)	$ (17,681)
Adjustment to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense		3
Non-cash research and development expense	258	821
Non-cash interest		1,166
Stock-based compensation	3,169	354
Loss on extinguishment of debt		201
Fair value of shares issued in exchange for research and development	449	1,974
Fair value of shares issued for incentive fee to Equilibria	941
Deferred income taxes		(41)
Severance costs paid by Galena	1,883
Changes in operating assets and liabilities:
Prepaid expenses and other assets	73	(477)
Accounts payable	8,366
Accrued expenses and other current liabilities	(2,374)	1,830
Net cash used in operating activities	(10,989)	(11,850)
Cash flows from investing activities:
Net cash acquired from acquisition of Galena	1,812
Change in restricted cash		(85)
Net cash provided by (used in) investing activities	1,812	(85)
Cash flows from financing activities:
Net proceeds from issuance of common stock	6,007
Net proceeds from issuance of convertible debt		15,000
Net proceeds from issuance of long-term debt		1,500
Principal payments on convertible debt	(473)
Net cash provided by financing activities	5,534	16,500
Net decrease (increase) in cash and cash equivalents	(3,643)	4,565
Cash and cash equivalents at the beginning of period	5,962	1,397
Cash and cash equivalents at end of period	2,319	$ 5,962
Supplemental disclosure of non-cash investing and financing activities:
Shares issued in connection with acquisition of Galena	12,487
Fair value of options assumed in connection with acquisition of Galena	32
Related party payable settled in shares	228
MSK payable settled in shares	150
Deemed dividend associated with conversion of 2015 Sely Note and common stock warrant issuance to Equilibria	675
2015 Shareholder Notes
Supplemental disclosure of non-cash investing and financing activities:
Shares issued upon conversion of notes and accrued interest	1,294
2015 Sely Note
Supplemental disclosure of non-cash investing and financing activities:
Shares issued upon conversion of notes and accrued interest	$ 6,064

Organization and Description of

Organization and Description of Business	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Organization and Description of Business	1. Organization and Description of Business Merger of Galena Biopharma, Inc. and SELLAS Life Sciences Group Ltd. As used in this annual report on Form 10-K, the words the “Company,” and “SELLAS” refer to SELLAS Life Sciences Group, Inc. and its consolidated subsidiaries following completion of the Merger. Said references before the completion of the Merger refer to Private SELLAS. On December 29, 2017, Galena Biopharma. Inc. (“Galena”) completed the business combination with the privately held Bermuda exempted company, Sellas Life Sciences Group Ltd. (“Private SELLAS”), in accordance with the terms of the Agreement and Plan of Merger and Reorganization, dated as of August 7, 2017 and amended November 5, 2017 the (“Merger Agreement”), by and among the Company, Sellas Intermediate Holdings I, Inc., Sellas Intermediate Holdings II, Inc., Galena Bermuda Merger Sub, Ltd., and Private SELLAS. The Company refers to this business combination throughout this annual report on Form 10-K Immediately prior to the Merger, the Galena effected a 1-for-30 pre-Merger Common stock as included in the consolidated statement of stockholders’ equity (deficit) was adjusted to reflect the $0.0001 par value per share and additional paid-in capital was adjusted as follows (in thousands): 2016 Retroactive 2016 Revised Balance at January 1, 2016 $ 288 $ 200 $ 488 Shares issued as partial consideration of MSK license fees 897 3 900 Shares issued pursuant to MSK license agreement 1,967 9 1,976 Shares issued in cancellation of Clarendon license agreement 500 2 502 Shares issued upon conversion of 2016 convertible note 15,357 54 15,411 Shares issued in cancellation of long-term debt 5,783 20 5,803 Stock-based compensation 354 — 354 Balance at December 31, 2016 $ 25,146 $ 288 $ 25,434 Upon completion of the Merger, the Company changed the Company’s name from “Galena Biopharma, Inc.” to “SELLAS Life Sciences Group, Inc.”, the Company’s common stock began trading on The Nasdaq Capital Market under a new ticker symbol “SLS” on January 2, 2018 and the Company’s financial statements became those of Private SELLAS. Overview The Company is a clinical-stage biopharmaceutical company focused on novel cancer immunotherapeutics for a broad range of cancer indications. The Company’s lead product candidate, galinpepimut-S (“GPS”), is a cancer immunotherapeutic agent licensed from Memorial Sloan Kettering Cancer Center (“MSK”), that targets the Wilms tumor 1 (“WT1”), protein, which is present in 20 or more cancer types. Based on its mechanism of action as a directly immunizing agent, GPS has the potential as a monotherapy or in combination with other immunotherapeutic agents to address a broad spectrum of hematologic, or blood, cancers and solid tumor indications. Phase 2 clinical trials for GPS have been completed and the Company’s planned Phase 3 clinical trials (pending funding availability) for two indications, acute myeloid leukemia (“AML”), and malignant pleural mesothelioma (“MPM”). GPS is also in development as a potential treatment for multiple myeloma (“MM”), and ovarian cancer. The Company plans to study GPS in up to four additional indications: as a combination therapy in small cell lung cancer, colorectal cancer, triple-negative breast cancer; and, as a monotherapy in chronic myelogenous leukemia (“CML”). The Company received Orphan Drug Product Designations from the U.S. Food and Drug Administration (“FDA”) as well as Orphan Medicinal Product Designations from the European Medicines Agency (“EMA”), for GPS in AML and MPM, as well as Fast Track designation for AML and MPM from the FDA. The Company’s pipeline also includes the legacy development programs of the pre-Merger -or GALE-301 GALE-302 GALE-401 GALE-301 GALE-302 GALE-401 GALE-301, GALE-302, GALE-401

Liquidity

Liquidity	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Liquidity	2. Liquidity The Company has not generated any revenues from product sales and has funded operations primarily from the proceeds of private placements of its equity interests (prior to the Merger) and convertible notes, as well as through the Merger. Substantial additional financing will be required by the Company to continue to fund its research and development activities. No assurance can be given that any such financing will be available when needed or that the Company’s research and development efforts will be successful. The Company regularly explores alternative means of financing its operations and seeks funding through various sources, including public and private securities offerings, collaborative arrangements with third parties and other strategic alliances and business transactions. On March 7, 2018, the Company entered into a definitive securities purchase agreement to issue shares of its convertible preferred stock (“Series A Convertible Preferred”) and warrants to purchase shares of its common stock in a private placement transaction to a select group of institutional investors. The Series A Convertible Preferred is expected to close in two tranches and result in aggregate gross proceeds to the Company of approximately $10.7 million. The Company closed the first tranche for approximately $6.0 million on March 9, 2018. The remaining $4.7 million will be received at the second closing, which is subject to stockholder approval, and is expected to occur early in the second quarter. In addition to the proceeds from the Series A Convertible Preferred, in the first quarter of 2018, JGB (Cayman) Newton Ltd (“JGB”) the holder the Company’s senior secured debenture due November 2018 redeemed $2.6 million of outstanding principal that was satisfied by the Company with 635,894 shares of the Company’s common stock and redeemed $0.6 million of outstanding principal, which the Company satisfied in cash. As a result of the redemptions, the Company was able to transfer $3.2 million out of restricted cash and cash equivalents and into unrestricted cash and cash equivalents to be used to fund the Company’s ongoing operations. The outstanding principal balance on the senior secured debenture as of April 6, 2018 is $7.0 million and is maintained by the Company as restricted cash. Other than as described in Note 15, the Company currently does not have any commitments to obtain additional funds and may be unable to obtain sufficient funding in the future on acceptable terms, if at all. If the Company cannot obtain the necessary funding, it will need to delay, scale back or eliminate some or all of its research and development programs or enter into collaborations with third parties to: commercialize potential products or technologies that it might otherwise seek to develop or commercialize independently; consider other various strategic alternatives, including a merger or sale of the Company; or cease operations. If the Company engages in collaborations, it may receive lower consideration upon commercialization of such products than if it had not entered into such arrangements or if it entered into such arrangements at later stages in the product development process. The Company has prepared its financial statements assuming that it will continue as a going concern, which contemplates realization of assets and the satisfaction of liabilities in the normal course of business. The Company has incurred net losses since inception and it expects to generate losses from operations for the foreseeable future primarily due to research and development costs for its potential product candidates, which raises substantial doubt about the Company’s ability to continue as a going concern. Various internal and external factors will affect whether and when the Company’s product candidates become approved drugs and how significant their market share will be, some of which are outside of the Company’s control. The length of time and cost of developing and commercializing these product candidates and/or failure of them at any stage of the drug approval process will materially affect the Company’s financial condition and future operations. The consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty. As of December 31, 2017, the Company had a cash balance of approximately $2.3 million and restricted cash at $10.4 million. In addition, the Company had outstanding accounts payable and accrued expenses of $14.9 million and indebtedness of $11.0 million as of December 31, 2017, which consists of the Company’s senior secured debenture with JGB. The Company expects its existing cash as of December 31, 2017, together with the proceeds from the initial closing of its Series A Convertible Preferred in March 2018, will enable the Company to fund its operating expenses and capital expenditure requirements through June 2018. Assuming that all conditions to the initial closing are met, the Company expects an additional $4.7 million of cash proceeds from the second closing of the sale of the Company’s Series A Convertible Preferred and warrants in the second quarter of 2018.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	3. Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”). Any reference in these notes to applicable guidance is meant to refer to U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). Principles of Consolidation The consolidated financial statements include the financial statements of the Company and its wholly owned subsidiaries, SELLAS Bermuda, SELLAS Life Sciences Group UK Ltd (“SELLAS UK”), Apthera, Inc. (“Apthera”) and Mills Pharmaceuticals, LLC (“Mills”). All significant intercompany accounts and transactions have been eliminated upon consolidation. Use of Estimates The preparation of these consolidated financial statements in accordance with U.S. 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 financial statements and the reported amounts of expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates using historical experience and other factors, including the current economic environment. Significant items subject to such estimates are assumptions used for purposes of determining stock-based compensation, the fair value of the warrants, beneficial conversion features associated with convertible notes, fair value of intangible assets acquired, carrying value of goodwill, fair value of contingent purchase price consideration, fair value of deferred tax liability assumed and accounting for research and development activities. Management believes its estimates to be reasonable under the circumstances. Actual results could differ significantly from those estimates. Fair Value of Financial Instruments The carrying amounts of the Company’s financial instruments, including cash equivalents, accounts payable, and accrued expenses approximate fair value due to the short-term nature of those instruments. The carrying amounts of the Company’s outstanding convertible notes approximate fair value due to the debt carrying a variable interest rate that is tied to the current London Interbank Offer Rate (“LIBOR”) rate. The fair value of the convertible notes is determined using a binomial lattice model that utilizes certain unobservable inputs that fall within Level 3 of the fair value hierarchy. The fair value of the warrants is determine using a Black-Scholes pricing model. Concentration of Credit Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist principally of cash on deposit with multiple financial institutions, the balances of which frequently exceed federally insured limits. Cash and Cash Equivalents The Company considers any highly liquid investments, such as money market funds, with an original maturity of three months or less to be cash and cash equivalents. Restricted Cash and Cash Equivalents Restricted cash consists of the minimum cash covenant as required by the debenture and certificates of deposit on hand with the Company’s financial institutions as collateral for its corporate credit cards. Intangible Assets Intangible assets are comprised of identifiable in-process written-off non-cash Goodwill Goodwill is the excess of the cost of an acquired entity over the net amounts assigned to tangible and intangible assets acquired and liabilities assumed. Goodwill is not amortized but is subject to an annual impairment test. The Company has a single reporting unit and all goodwill relates to that reporting unit. The Company performs its annual goodwill impairment test at the reporting unit level on October 1 of each fiscal year or more frequently if changes in circumstances or the occurrence of events suggest that an impairment exists. Goodwill is evaluated for impairment using the simplified test of goodwill impairment as defined by the FASB Accounting Standards Update No. 2017-04. Severance Costs The Company recognized and paid $1.9 million of exit costs during 2017 related to severance benefits for former Galena employees terminated immediately prior to the consummation of the Merger. Patents and Patent Application Costs Although the Company believes that its patents and underlying technology have continuing value, the amount of future benefits to be derived from the patents is uncertain. Patent costs are, therefore, expensed as incurred. Legal Fees and Insurance Recoveries There can be a significant time lag between the time that legal fees are incurred and the insurance reimbursement available to offset the related costs. The legal fees are recorded in the period they are incurred, and the insurance recoveries for those costs are recorded in the period when the insurance reimbursement is deemed probable. Stock-based Compensation The Company follows the provisions of the FASB ASC Topic 718, “ Compensation — Stock Compensation” non-employee For stock options and warrants granted as consideration for services rendered by non-employees, 505-50 505-50”), Equity Based Payments to Non- Non-employee re-measured non-cash non-employees re-measurements Research and Development Expenses Research and development costs are expensed as incurred. Research and development costs that are paid in advance of performance are capitalized as a prepaid expense and amortized over the service period as the services are provided. Clinical study costs, a component of research and development expenses, are accrued over the service periods specified in the contracts and adjusted as necessary based on an ongoing review of the level of effort and costs actually incurred. Payments for a product license prior to regulatory approval of the product and payments for milestones achieved prior to regulatory approval of the product are expensed in the period incurred as research and development expenses. Milestone payments made in connection with regulatory approvals are capitalized and amortized to cost of revenue over the remaining useful life of the asset. Research and development expenses primarily consist of the intellectual property and research and development materials acquired, expenses from third parties who conduct research and development activities on behalf of the Company as well as related wages, benefits and other operating costs. The Company expenses in-process research and development projects acquired as asset acquisitions which have not reached technological feasibility and which have no alternative future use. Income Taxes The Company uses the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The Company recognizes the benefit of an uncertain tax position that it has taken or expects to take on its income tax return it files, if such a position is more likely than not to be sustained. The Company recognizes liabilities or assets for the deferred tax consequences of temporary differences between the tax basis of assets or liabilities and their reported amounts in the financial statements in accordance with FASB ASC 740-10, Accounting for Income Taxes” (“ASC 740-10”). ASC 740-10 On December 22, 2017 the President of the United States signed into law the Tax Cuts and Jobs Act (“The 2017 Tax Act”). This legislation makes significant changes in the United States tax laws including, but not limited to, reducing the corporate tax rate to 21% starting in 2018. The 2017 Tax Act required the Company to revalue its deferred tax assets and liabilities to the new rate of 21%. For the years ended December 31, 2017 and 2016, the Company recognized income tax expense of $253,000 and $1,000, respectively. Staff Accounting Bulletin No. 118 (“SAB 118”) was issued to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Act. In accordance with SAB 118, we determined that the adjustment to deferred taxes was a provisional amount and a reasonable estimate at December 31, 2017. We do not expect any impact on recorded deferred tax balances as the remeasurement of net deferred tax assets will be offset by a change in valuation allowance. We are analyzing certain aspects of the Tax Act which could potentially affect the remeasurement of the net deferred tax assets. Net Loss Per Share Basic loss per share is computed by dividing net loss applicable to common stockholders by the weighted average number of shares of common stock outstanding during each period. Diluted loss per share includes the effect, if any, from the potential exercise or conversion of securities, such as convertible debt, warrants, stock options and unvested restricted stock that would result in the issuance of incremental shares of common stock. In computing the basic and diluted net loss per share, the weighted average number of shares remains the same for both calculations due to the fact that when a net loss exists, dilutive shares are not included in the calculation as the impact is anti-dilutive. The following potentially dilutive securities outstanding have been excluded from the computation of diluted weighted average shares outstanding, as they would be anti-dilutive: Year ended December 31, 2017 2016 Common stock warrants 963 — Stock options 10 55 Unvested restricted stock awards 13 67 986 122 Amounts in the table reflect the common stock equivalents of the noted instruments. Comprehensive Loss The Company has no items of comprehensive income or loss other than net loss. Recently Issued Accounting Pronouncements In July 2017, the FASB issued ASU 2017-11, Earnings Per Share (Topic 260); Distinguishing Liabilities from Equity (Topic 480); Derivatives and Hedging (Topic 815): (Part I) Accounting for Certain Financial Instruments with Down Round Features, (Part II) Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception. In May 2017, the FASB issued Accounting Standard Update No. 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting 2017-09 In November 2016, the FASB issued ASU No. 2016-18, Restricted cash In March 2016, the FASB issued Accounting Standards Update 2016-09, Compensation-Stock Compensation 2016-09 2016-09 In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases right-of-use

Business Combination

Business Combination	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Business Combination	4. Business Combination On December 29, 2017, the Company completed the Merger with Private SELLAS as discussed in Note 1. The Merger was accounted for as reverse merger under the acquisition method of accounting whereby Private SELLAS was considered to have acquired the Company for financial reporting purposes because, immediately upon completion of the Merger, Private SELLAS stockholders held a majority of the voting interest of the combined company. Immediately after the Merger, stockholders of Private SELLAS and the Company’s common stock, warrants and options owned approximately 67.5% and 32.5% of the fully diluted common stock of the Company, respectively. The purchase consideration in a reverse acquisition is determined with reference to the value of equity that the accounting acquirer, in this case, Private SELLAS, would have had to issue to the owners of the accounting acquiree, the Company, to give the pre-acquisition pre-acquisition Fair value of the Company’s pre-Merger $ 12,487 Estimated fair value of the Company’s per-Merger 32 Total purchase price $ 12,519 The Merger transaction has been accounted for using the acquisition method of accounting, which requires that assets acquired and liabilities assumed be recognized at their fair values as of the acquisition date. See Note 5 for the valuation technique utilized to value the IPR&D. The following table summarizes the allocation of the purchase price to the assets acquired and liabilities assumed as of the acquisition date (in thousands): Assets acquired: Cash $ 1,812 Restricted cash 10,346 Prepaid expenses and other assets 3,103 Intangible assets 17,600 Goodwill 1,914 Total assets acquired $ 34,775 Liabilities assumed: Accounts payable and accrued expenses $ 5,692 Litigation settlement 1,300 Long-term debt 10,988 Contingent purchase price consideration of Apthera, Inc. 1,294 Warrant liability 1,309 Deferred tax liability 1,673 Total liabilities assumed $ 22,256 Net assets acquired $ 12,519 Qualitative factors supporting the recognition of goodwill due to the Merger include the Company’s anticipated enhanced ability to secure additional capital and gain access to capital market opportunities as a public company. The goodwill is not deductible for income tax purposes. The following summary pro forma consolidated financial information reflects the Merger as if it had occurred on January 1, 2016 for purposes of the statements of operations. This summary pro forma information is not necessarily representative of what the Company’s results of operations would have been had the Merger in fact occurred on January 1, 2016, and is not intended to project the Company’s results of operations for any future period. In addition, transaction costs associated with the Merger of $5.7 million are included in general and administrative expense in the statement of operations for the year ended December 31, 2017. Pro forma consolidated financial information for 2017 and 2016 (unaudited): Year ended December 31, 2017 2016 Net revenues (in thousands) $ — $ — Net loss (in thousands) $ 24,089 $ 28,389 Basic and diluted net loss per share $ 5.15 $ 8.61 Non-recurring

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	5. Goodwill and Intangible Assets The Company completes its annual impairment test on October 1 each year, or more frequently if triggering events indicate a possible impairment. The Company continually evaluates financial performance, economic conditions and other relevant developments in assessing if an interim period impairment test is necessary. Changes in the carrying amount of goodwill for the period ended December 31, 2017 consisted of the following (in thousands): Balance as of January 1, 2017 $ — Goodwill as a result of the Merger 1,914 Balance as of December 31, 2017 $ 1,914 Intangible assets consist of IPR&D acquired as part of the Merger. IPR&D assets represent research and development assets that have not yet reached commercialization. At December 31, 2017, the significant components of the Company’s IPR&D assets consist of the NeuVax program for the prevention of recurrence in breast cancer, the GALE-401 GALE-301 GALE-302 The Company’s allocation of purchase price to acquired IPR&D was $17.6 million. The estimated fair value of the GALE-401 GALE-401 GALE-301 GALE-302 IPR&D assets are required to be classified as indefinite-lived assets until the successful commercialization of the asset or the abandonment of the associated R&D effort. These assets are assessed for impairment annually on October 1 or more frequently if impairment indicators exist. Accordingly, during the development period after the date of acquisition, these assets will not be amortized until commercialization is reached. For those programs that reach commercialization, the Company will determine the useful life of the asset, reclassify the asset out of IPR&D and begin amortization. If the associated R&D effort is abandoned, the related IPR&D assets will likely be written-off, non-cash

Collaboration and License Agree

Collaboration and License Agreements	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaboration and License Agreements	6. Collaboration and License Agreements As part of its business, the Company enters into licensing agreements with third parties that often require milestone and royalty payments based on the progress of the licensed asset through development and commercial stages. Milestone payments may be required, for example, upon approval of the product for marketing by a regulatory agency, and the Company may be required to make royalty payments based upon a percentage of net sales of the product. The expenditures required under these arrangements in any period may be material and are likely to fluctuate from period to period. These arrangements sometimes permit the Company to unilaterally terminate development of the product and thereby avoid future contingent payments; however, the Company is unlikely to cease development if the compound successfully achieves clinical testing objectives. Memorial Sloan Kettering Cancer Center On September 4, 2014, (the “MSK Effective Date”) the Company entered into a license agreement (the “Original MSK License Agreement”) with MSK under which the Company was granted an exclusive license to develop and commercialize MSK’s WT1 peptide vaccine technology. Under the terms of the Original MSK License Agreement, the Company is required to obtain certain levels of financing. If such financing is not met, MSK will have the right to terminate the Original MSK License Agreement with prior written notice, unless the Company manages to overcome the shortfall during the term of the notice period. As part of the consideration for the rights, privileges and licenses granted under the Original MSK License Agreement, the Company agreed to issue 13,199 shares to MSK representing 1.5% of the Company’s fully diluted share capital as of the MSK Effective Date, which obligation was satisfied by assignment of 6,599 shares from each of the Company’s Chief Executive Officer, co-founder co-founder, The Original MSK License Agreement, unless terminated earlier in accordance with the terms of the Original MSK License Agreement, will continue on a country-by-country product-by-licensed On October 30, 2015, the Company and MSK entered into the License Amendment, Waiver and Share Issuance Agreement (the “First MSK Amendment”). The First MSK Amendment extended the date required for the Company to obtain financing from August 1, 2015 to December 31, 2016, modified the amount of required financing and waived past non-compliance On August 10, 2016, the Company and MSK entered into the Second License Amendment, Waiver and Agreement (the “Second MSK Amendment”). The Second MSK Amendment extended further the date required for the Company to obtain financing from December 31, 2016 to June 30, 2017, amended the anti-dilution provisions of the First MSK Amendment and waived past non-compliance re-domiciliation For the year ended December 31, 2017, the Company incurred $1.0 million of expenses relating to $0.7 million of milestone payments, $0.1 million of guaranteed minimum royal payments and $0.2 million of research funding costs. For the year ended December 31, 2016 the Company incurred $0.6 million of expenses relating to $0.3 million of milestone payments, $0.1 million of guaranteed minimum royal payments and $0.2 million of research funding costs. Such expenses have been included in research and development costs. Further, under the Second MSK Amendment, the Company is obligated to pay MSK $0.7 million in milestone payments in two equal installments, within 60 days following the initiation of its Phase 3 AML and mesothelioma clinical studies. On May 25, 2017, the Company and MSK entered into an Amended and Restated Exclusive License Agreement (the “MSK A&R License Agreement”). Under the MSK A&R License Agreement, the Company expanded its license under the original MSK License Agreement, as amended, to include a license to commercially develop certain additional WT1 peptides through a program of exploiting certain patents and other rights covering such peptides. The MSK A&R License Agreement, amongst others, added certain milestone payments for each additional patent licensed product as defined in the MSK A&R License Agreement, and amended the milestone payments due upon commencement of the Phase 3 AML and mesothelioma clinical trials from $0.3 million to $0.4 million. In consideration for the MSK A&R License Agreement, the Company issued 8,799 shares to MSK. Pursuant to a side letter to the MSK A&R License Agreement, dated May 25, 2017 (the “MSK Side Letter”), MSK converted the next milestone payment of $0.2 million, which was due June 30, 2017, into shares. Further, in consideration for the MSK Side Letter, Dr. Angelos M. Stergiou (M.D., Sc.D. h.c.), the Company’s Chief Executive Officer, assigned 15,399 of his shares to MSK, for which Dr. Stergiou received no cash consideration. On October 11, 2017, the Company and MSK entered into a second Amended and Restated Exclusive License Agreement (the “Second MSK A&R License Agreement”). Under the Second MSK A&R License Agreement, the Company and MSK extended the dates for the Company to have obtained necessary financing, and certain milestone dates, in exchange for increased milestone payments, clarification regarding MSK’s anti-dilution rights, and termination of the MSK Side Letter dated May 25, 2017. In connection with the MSK A&R License Agreement, the Company issued 74,795 shares to MSK. Prior to the Merger, the Company issued an additional 7,700 shares to MSK in connection with their anti-dilution rights. Merck & Co., Inc. On September 21, 2017, the Company entered into a clinical trial collaboration and supply agreement through a Merck & Co., Inc. subsidiary, Merck Sharp & Dohme B.V. (“Merck subsidiary”), whereby the Company agreed with the Merck subsidiary to collaborate in a research program to evaluate GPS as it is administered in combination with Merck’s PD1 blocker pembrolizumab (Keytruda ® The purpose of the clinical trials is to determine if the administration of GPS in combination with pembrolizumab has the potential to demonstrate clinical activity in the presence of macroscopic disease, where monotherapy with either agent would have a more limited effect. The rationale for the study is based upon the presumed immunobiologic and pharmacodynamic synergy between the two agents, whereby the negative influence of tumor microenvironment factors on the immune response is mitigated by PD1 inhibition (by pembrolizumab) thus allowing the patients’ own immune cells to invade and destroy cancerous growth deposits specifically sensitized against WT1 by GPS. The Phase 1/2 clinical trial will utilize a combination of GPS plus pembrolizumab (Keytruda) in patients with WT1+ relapsed or refractory tumors. Specifically, the study is expected to explore the following cancer indications: colorectal (arm enriched in but not exclusive to patients with microsatellite instability-low), Advaxis, Inc. On February 24, 2017, the Company and Advaxis, Inc. (“Advaxis”) entered into a research and development collaboration agreement, whereby both parties will collaborate in a research program to evaluate, through a “proof of principle” trial or trials (“PoP Clinical Trial”), a clinical candidate comprised of the combination of Advaxis’ proprietary Lm- The Advaxis agreement provides for cost-sharing between the parties, with Advaxis being responsible for the costs of performing the research activities and filing any investigational new drug application (“IND”), cost-sharing for preparation of the IND, and the Company being responsible for the costs (exclusive of product costs) of conducting the PoP trial. The Company also agreed to make certain non-refundable non-refundable Trojantec Ltd. On November 14, 2014, the Company entered into a license agreement with Trojantec Ltd., (“Trojantec”), a company incorporated in Cyprus, under which the Company was granted an exclusive license to develop and commercialize Trojantec’s TR1 Antenapedia/p21 protein treatment. In consideration for entering into the Trojantec License Agreement and for the rights, privileges and licenses granted, the Company incurred $0.3 million of license fees during the year ended December 31, 2014. Under the license agreement, the Company would be obligated to pay Trojantec royalties on net sales, if any, and milestone payments related to the achievement of certain clinical and regulatory goals. On July 14, 2015, the Company and Trojantec entered into the First Amended and Restated Exclusive License Agreement. The amendment reinstated the obligations of the Company under the original license agreement and further obligated the Company to pay project management fees of up to $0.4 million. On June 15, 2016, the Company entered into an agreement with Trojantec to terminate the license agreement. In consideration for the termination agreement, the Company incurred and paid in cash $0.1 million of termination fees. Such fees were included in research and development expenses for the year ended December 31, 2016. Clarendon Trading e Investimentos LDA On January 18, 2016, the Company entered into a license arrangement with Clarendon Trading e Investimentos LDA (“Clarendon”), a company incorporated in Portugal. Under the license agreement, the Company was granted an exclusive license to know-how Effective September 30, 2016, the Company entered into termination agreement with Clarendon to terminate the license agreement. In consideration for the termination agreement and in complete satisfaction of the Company’s outstanding liabilities, the Company agreed to pay Clarendon $0.3 million in cash and issue Clarendon 7,700 shares. In extinguishment of the Company’s outstanding liabilities to Clarendon, the Company incurred an additional $0.2 million of expense to reflect the fair value of the shares issued to Clarendon. The Company’s predecessor company, Galena entered into the following licensing and/or supply agreements, which the Company acquired through the Merger: The University of Texas M. D. Anderson Cancer Center and The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. On September 11, 2006, the Company acquired rights and assumed obligations under a license agreement among Apthera and The University of Texas M. D. Anderson Cancer Center (“MDACC”) and The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (“HJF”) which grants exclusive worldwide rights to a United States patent covering the nelipepimut-S peptide and several United States and foreign patents and patent applications covering methods of using the peptide as a vaccine. Under the terms of this license, the Company is required to pay an annual maintenance fee of $0.2 million, clinical milestone payments and royalty payments based on sales of NeuVax or other therapeutic products developed from the licensed technologies. Biovascular, Inc. On December 20, 2013, Mills and BioVascular, Inc. (“BioVascular”) entered into an exclusive license agreement. In 2014, through the Company’s acquisition of Mills, the Company’s wholly owned subsidiary, the Company acquired worldwide rights to to develop and commercialize anagrelide controlled release formulation, GALE-401. GALE-401 FDA-approved mid-to-low On September 5, 2017, Mills and BioVascular entered into an amendment to license agreement to modify the certain terms of the license agreement, including but not limited to, (i) eliminating the 3% royalty rate on annual net sales of $50.0 million and the 4% royalty now applies to annual net sales of up to $100.0 million, (ii) making an advance payment of approximately $0.4 million for the milestone related to the initiation of the Phase 3 clinical trial payable in two tranches with the first payment of $0.2 million payable on or before October 31, 2017 and the second payment of approximately $0.2 million payable 30 days after the consummation of the Merger but no later than December 31, 2017, (iii) adding a payment for a sublicense by Mills to a third party of 25% of any cash received for upfront fees or milestone payments if the sublicense is executed prior to first patient enrolled in the Phase 3 clinical trial and 17.5% of any cash received for upfront fees or milestone payments if the sublicense is executed after the first patient is enrolled in the Phase 3 clinical trial, and (iv) if the first patient is not enrolled in the Phase 3 clinical trial by December 31, 2018, BioVascular shall have the right to terminate the license agreement and the advance payment shall not be repaid to Mills. Under the terms of a September 5, 2017 consent between Comerica Bank, BioVascular and Mills, Comerica Bank shall receive $0.1 million of the approximately $0.4 million advance payment from Mills. Teva Pharmaceuticals In conjunction with the Merger, acquisition of NeuVax, and effective December 3, 2012, the Company entered into a license and supply agreement with ABIC Marketing Limited (“ABIC”), a subsidiary of Teva Pharmaceuticals. Under the agreement, the Company granted ABIC exclusive rights to seek marketing approval in Israel for NeuVax for the treatment of breast cancer following its approval by the FDA or the EMA, and to market, sell and distribute NeuVax in Israel assuming such approval is obtained. ABIC’s rights also include a right of first refusal in Israel for all future indications for which NeuVax may be approved. Under the license and supply agreement, ABIC will assume responsibility for regulatory registration of NeuVax in Israel, provide financial support for local development, and commercialize the product in the region in exchange for making royalty payments to us based on future sales of NeuVax. ABIC also agrees in the license and supply agreement to purchase all supplies of NeuVax from the Company at a price determined according to a specified formula. Dr. Reddy’s Laboratories Ltd. In conjunction with the Merger, acquisition of NeuVax, and effective January 14, 2014, the Company entered into a strategic development and commercialization partnership with Dr. Reddy’s Laboratories Ltd. (“Dr. Reddy’s”), under which the Company licensed commercial rights in India to Dr. Reddy’s for NeuVax in breast and gastric cancers. The Company has an agreement with Dr. Reddy’s to conduct a Phase 2 investigational study in gastric cancer in India. To date, Dr. Reddy’s has not initiated the Phase 2 study with NeuVax. Kwang Dong Pharmaceutical Co., Ltd. In conjunction with the Merger, acquisition of NeuVax, and effective April 30, 2009, the Company entered into a license agreement with Kwang Dong Pharmaceutical Co, Ltd. (“Kwang Dong”). Under the agreement, the Company granted Kwang Dong exclusive rights to seek marketing approval in The Republic of Korea, or South Korea for NeuVax for the treatment of breast cancer following its approval by the FDA or the EMA, and to market, sell and distribute NeuVax in South Korea assuming such approval is obtained.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Investments, All Other Investments [Abstract]
Fair Value Measurements	7. Fair Value Measurements The following tables present information about the Company’s assets and liabilities measured at fair value on a recurring basis in the consolidated balance sheets (in thousands): Description December 31, Quoted Prices In Significant Other Unobservable Assets: Cash equivalents $ 1,662 $ 1,662 $ — $ — Restricted cash equivalents 10,245 10,245 — — Total assets measured and recorded at fair value $ 11,907 $ 11,907 $ — $ — Liabilities: Warrants potentially settleable in cash $ 1,309 $ — $ — $ 1,309 Contingent consideration 1,294 — — 1,294 Total liabilities measured and recorded at fair value $ 2,603 $ — $ — $ 2,603 The Company did not transfer any financial instruments into or out of Level 3 classification during the year ended December 31, 2017. The contingent consideration was assumed by the Company in connection with the Merger and recorded at fair value as of the consummation of the Merger, which approximates fair value as of December 31, 2017. The fair value of the contingent consideration is measured at the end of each reporting period using Level 3 inputs in a probability-weighted, discounted cash-outflow model. The contingent consideration relates to Galena’s acquisition of Apthera, Inc. in 2011 and the future contingent payments of up to $32 million based on the achievement of certain development and commercial milestones relating to the Company’s NeuVaxTM product candidate. The contingent consideration is payable at the election of the Company in either cash or shares of common stock, provided that the Company may not issue any shares in satisfaction of any contingent consideration unless it has first obtained approval of its stockholders in accordance with Rule 5635(a) of the Nasdaq Marketplace Rules. The significant unobservable assumptions include the probability of achieving each milestone, the date we expect to reach the milestone, and a determination of present value factors used to discount future expected cash outflows. At December 31, 2016, the estimated fair value of the 2015 Notes was $7.3 million, which compared to a carrying value of $7.4 million. See also Note 9. See Note 12 for discussion of the Level 3 liabilities relating to warrants accounted for as liabilities.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2017
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	8. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following (in thousands): Year Ended December 31, 2017 2016 Professional fees $ 1,744 $ 1,077 Value added tax 426 — Rebates and returns 223 — Compensation and related benefits 566 249 Clinical trial costs 51 2,496 Other 191 227 Accrued expenses and other current liabilities $ 3,201 $ 4,049

Debt

Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Debt	9. Debt Debt and convertible debt consist of the following (in thousands): Year Ended December 31, 2017 2016 Debt Current portion of Senior Secured Debenture $ 8,377 $ — Non-current portion of Senior Secured Debenture 2,611 — Total debt $ 10,988 $ — Convertible debt 2015 Shareholder Notes $ — $ 1,709 2015 Sely Note — 5,659 Total convertible debt $ — $ 7,368 Senior Secured Debenture On May 10, 2016, the Company’s predecessor company, Galena entered into a securities purchase agreement, with JGB pursuant to which Galena sold to JGB, at a 6.375% original issue discount, a $25.5 million senior secured debenture (the “Senior Secured Debenture”) and warrants to purchase up to 3,333 shares of Galena’s common stock, $0.0001 par value per share. Net proceeds to Galena from sale of the Senior Secured Debenture and warrants, after payment of commissions and legal fees, was approximately $23.4 million. The Senior Secured Debenture contained no conversion features to shares of common stock. The Senior Secured Debenture remains outstanding for the Company through the consummation of the Merger with Galena on December 29, 2017. The Senior Secured Debenture matures on November 10, 2018, and accrues interest at 9% per year, payable monthly. In addition, on the maturity date of the Senior Secured Debenture (or such earlier date that the principal amount of the Senior Secured Debenture is paid in full by acceleration or otherwise) a fixed amount, which shall be deemed interest under the Senior Secured Debenture, equal to $0.8 million will be due and payable to JQB of the Senior Secured Debenture on such date in, at the option of the Company, cash and, subject to the same conditions for the payment of interest in shares of the Company’s common stock, or a combination of cash and the Company’s common stock The Company’s obligations under the Senior Secured Debenture are secured under the security purchase agreement by a senior lien on all of the Company’s assets, including all of the Company’s interests in its consolidated subsidiaries. Under the subsidiary guarantee agreement, each subsidiary guarantees the performance of the Company of the securities purchase agreement, Senior Secured Debenture and related agreements. The Senior Secured Debenture was amended in August 2016, May 2017, July 2017 and August 2017. After giving effect to the amendments, the Senior Secured Debenture contains the following modified and/or additional terms, among others: • JGB can from time to time during the term of the Senior Secured Debenture require the Company to prepay in cash all or a portion of the outstanding principal plus accrued and unpaid interest (the “Outstanding Amount”) on written notice to the Company, provided, that such prepayment amount shall not exceed the lesser of $18.5 million and the outstanding principal amount. If JGB elects such prepayment of the Senior Secured Debenture, then the number of shares subject to the warrants issued to the holder will be reduced in proportion to the percentage of principal and accrued interest required to be prepaid by the Company. The Company does not have the right to prepay. • JGB has the right, which commenced on November 10, 2016, to require the Company to redeem the outstanding principal amount, up to the outstanding principal amount of the Senior Secured Debenture by written notice to the Company and may deliver an unlimited number of redemption notices during any calendar month. • The Company has the option to pay outstanding principal redemptions and monthly interest in shares of common stock, cash, or a combination of shares of common stock and cash. Among the various conditions that must be satisfied (or waived) in order for the Company to be able to elect to satisfy the redemption amounts in shares of common stock: (a) the VWAP of $10.50 per share on any trading day that a redemption notice is delivered (b) no event of default has occurred and is continuing and (c) the Company’s cash on hand exceeds the outstanding principal amount by at least $10.0 million. In the event that any of these conditions are not met, the Company does not have the option to pay outstanding principal redemptions and monthly interest in cash. • The stock payment price to satisfy outstanding principal redemptions and monthly interest is the lower of (a) 80% of the VWAP for the trading day immediately prior to the date of the applicable redemption notice (the “Prior Day VWAP”) and (b) 80% of the average of the three lowest VWAPs during the 20 consecutive trading day period immediately preceding the date of the applicable redemption notice (the “Twenty Day VWAP”); provided, however, to the extent that, on any given trading day, the price per share of common stock on such trading day equals or exceeds 115% of the Prior Day VWAP or Twenty Day VWAP, then for the such trading day, and such trading day only, each reference to 80% shall be deemed, for such trading day only, to be 92.5% • The Company was required to maintain a minimum of the lesser of $18.5 million or the outstanding principal amount of unencumbered cash in a restricted account. As of December 31, 2017, the Company maintained $10.2 million of cash and cash equivalents in a restricted account equal to the outstanding principal amount. As of December 31, 2017, the outstanding principal balance of the Senior Secured Debenture was $10.2 million. In addition to the outstanding principal balance, on the earlier of the maturity date or the date that the principal amount is paid in full, the Senior Secured Debenture has a $0.8 million additional interest amount that is included in the current portion of long-term debt as of December 31, 2017. Subsequent to December 31, 2017, the holder of the Senior Secured Debenture redeemed an additional $2.6 million of outstanding principal, which the Company satisfied with a combination of 623,749 shares of the Company’s common stock and redeemed $0.6 million of outstanding principal, which the Company satisfied with $0.6 million in cash. As of result of the redemptions, the Company was able to transfer $3.2 million out of restricted cash and cash equivalents and into unrestricted cash and cash equivalents to be used to fund the Company’s ongoing operations. The principal redemptions of $2.6 million subsequent to December 31, 2017 that were satisfied with shares of the Company’s common stock are classified as long-term debt, as of December 31, 2017, as the amounts were not satisfied with working capital. 2015 Convertible Term Notes, as of December 31, 2017 On April 2, 2015, the Company issued an aggregate of $1.5 million in principal amount of convertible term notes to certain stockholders of the Company (the “2015 Shareholder Notes”) and on May 7, 2015, the Company issued a convertible term note in the principal amount of $5.0 million to EQC Biotech Sely I Fund (“EQC Sely I Fund”), a related party of the Company (the “2015 Sely Note” and, together with the 2015 Shareholder Notes, the “2015 Notes”). The holders of the 2015 Shareholder Notes include two of the significant stockholders and founding investors of the Company, Drs. Angelos M. Stergiou (M.D., ScD h.c.), the Company’s CEO and Miltiadis Sougioultzoglou (M.D.). The 2015 Notes were issued at par and bear an interest rate of 8%. The 2015 Shareholder Notes matured on April 2, 2017 and the 2015 Sely Note originally matured on May 7, 2017. In August 2017, the Company and EQC Sely I Fund further amended the 2015 Sely Note to agree the number of shares issuable upon consummation of the Merger. Accordingly, contingent upon and effective immediately prior to completion of the Merger, the Company will issue to EQC Sely I Fund 632,328 of its common shares and 5-year warrants On June 13, 2017, the Board of Directors approved a $7.3 million capital increase (the “Bridge Financing”), pursuant to which an aggregate of 1,865,261 shares were issued at a price per share equal to approximately $3.91. As part of the Bridge Financing, an aggregate of $1.3 million (330,551 shares) was subscribed by certain stockholders who are also the holders of the 2015 Shareholder Notes. The cash proceeds were used to partially offset the principal ($1.2 million) and cumulative accrued interest ($0.1 million) due on the 2015 Shareholder Notes. Following the Bridge Financing, the Company extinguished in cash its remaining obligations on the 2015 Shareholder Notes, which included $0.3 million of principal and $0.2 million of cumulative accrued interest as of June 21, 2017. On December 29, 2017, the Company issued 632,326 shares of common stock and warrants to purchase 316,163 of its common stock in full satisfaction of the 2015 Sely Note. The 2015 Sely Note conversion was considered to be an induced conversion and extinguishment and the Company realized a loss of $0.7 million during the year ended December 31, 2017. The Company considered the extinguishment to be a capital transaction and it was therefore recorded in the Company’s consolidated statements of stockholders’ equity (deficit). 2016 Convertible Term Note On June 30, 2016, the Company issued a $15.0 million convertible term note to EQC Sely I Fund (the “2016 Note”). The 2016 Note was issued at par and had an interest rate of 8%. The 2016 Note was issued with similar terms to the 2015 Notes (excluding the warrant coverage) whereby the 2016 Note is mandatorily convertible into equity upon the earlier to occur: a) the closing of a qualified IPO, b) a change in the Company’s domicile from Switzerland to Bermuda or c) the six-month On November 1, 2016, the Company redomiciled its operations from Switzerland to Bermuda and therefore, the 2016 Note, together with accrued interest, was converted into 236,705 shares of its common stock based upon a pre-agreed Long-term Debt On March 2, 2015, the Company entered into a loan agreement with a third party whereby the third party granted a $2.5 million loan to the Company (the “2015 Loan Agreement”). On December 24, 2015, the counterparty to the 2015 Loan Agreement reassigned all of its rights, interests and benefits under such agreement to Starcove Ltd., a company incorporated in Cyprus and a shareholder of the Company (“Starcove”). There were no further changes made to the 2015 Loan Agreement as a result of the reassignment. The term of the loan granted under the 2015 Loan Agreement was 24 months with an interest rate of 8%. On April 6, 2016, the Company entered into a second loan agreement with Starcove (the “Framework Loan Agreement”), whereby Starcove extended a line of credit to the Company of $1.5 million with an interest rate of 6%. The term of the Framework Loan Agreement was three years. All principal and accrued interest would be payable in a single payment on April 6, 2019 unless earlier paid but no sooner than six months from the date of the Framework Loan Agreement. As of December 31, 2016, the Company had made three withdrawals under the credit line: (1) $0.6 million on April 12, 2016, (2) $0.6 million on May 12, 2016 and (3) $0.3 million on June 2, 2016. On November 1, 2016, an aggregate amount of $4.4 million, which represented the principal and accrued interest under the 2015 Loan Agreement and the Framework Loan Agreement (together, the “Starcove Loans”), was extinguished upon the issuance of 67,140 shares of the Company’s common stock with an estimated fair value equal to the carrying value of the debt. On November 25, 2013, the Company entered into a loan agreement with a shareholder, whereby the shareholder granted a EUR 1.8 million loan to the Company (the “2013 Loan Agreement”). The term of the loan was open-ended and had an interest rate of 5%. On January 1, 2014, the principal amount of the 2013 Loan Agreement, together with accrued interest, was re-assigned on a 50:50 basis to the Company’s co-founders, Drs. Angelos M. Stergiou (M.D., Sc.D. h.c.) and Miltiadis Sougioultzoglou (M.D.). On December 31, 2015, the Company entered into an agreement with each of Drs. Stergiou and Sougioultzoglou, whereby the Company’s aggregate obligation of EUR 1.8 million, together with accrued interest equal to EUR 0.1 million as of such date, as well as an additional EUR 0.1 million of payables due to them from the Company, were offset by an aggregate amount of EUR 0.7 million representing receivables due to the Company from Drs. Stergiou and Sougioultzoglou pursuant to various other agreements that were entered into in 2012 and 2013. As a result, as of December 31, 2015, the amount of the Company’s outstanding loans to Drs. Stergiou and Sougioultzoglou were EUR 0.7 million and EUR 0.6 million, respectively (each, a “Founder Loan” and together, the “Founder Loans”). The interest rate on the Founder Loans was 2.5% and the term of the Founder Loans was three years. The original and modified loans were not considered substantially different as the difference between the present value of the remaining cash flows under the original and the modified terms was less than 10%. As such, extinguishment accounting did not apply. On November 1, 2016, an aggregate amount of EUR 0.7 million and EUR 0.6 million, which represented the principal and accrued interest under each respective Founder Loan, were converted into 11,571 and 10,383 shares, respectively. The number of shares issued was based on the fair value of the Company’s shares at the conversion date and therefore no gain or loss was recognized upon the cancellation of the loans.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	10. Commitments and Contingencies Legal Proceedings From time to time, the Company is subject to various pending or threatened legal actions and proceedings, including those that arise in the ordinary course of its business, which may include employment matters, breach of contract disputes and stockholder litigation. Such actions and proceedings are subject to many uncertainties and to outcomes that are not predictable with assurance and that may not be known for extended periods of time. The Company records a liability in its consolidated financial statements for costs related to claims, including future legal costs, settlements and judgments, when the Company has assessed that a loss is probable and an amount can be reasonably estimated. If the reasonable estimate of a probable loss is a range, the Company records the most probable estimate of the loss or the minimum amount when no amount within the range is a better estimate than any other amount. The Company discloses a contingent liability even if the liability is not probable or the amount is not estimable, or both, if there is a reasonable possibility that a material loss may have been incurred. In the opinion of management, as of the date hereof, the amount of liability, if any, with respect to these matters, individually or in the aggregate, will not materially affect the Company’s consolidated results of operations, financial position or cash flows. The Company’s predecessor company, Galena was involved in multiple legal proceedings and administrative actions, including stockholder class actions, both state and federal, some of which are ongoing and to which the Company is now subject as a result of the Merger. They are as follows: Settled Matters On December 16, 2015, Galena received a subpoena issued by the U.S. Attorney’s Office for the District of New Jersey (“USAO NJ”), requesting the production of a broad range of documents pertaining to Galena’s marketing and promotional practices for Abstral. Through its communications with the USAO NJ and the U.S. Department of Justice (“DOJ”), Galena came to understand that the investigation being undertaken by the USAO NJ and DOJ was a criminal investigation in addition to a civil investigation that could ultimately involve Galena as well as one or more former employees. Pursuant to Galena’s charter, Galena was reimbursing certain former employees’ attorney’s fees with respect to the investigation but stopped on May 1, 2017. Galena cooperated with the civil, and is continuing to cooperate with the criminal, investigations, and on September 8, 2017, DOJ announced a settlement agreement with Galena regarding the USAO NJ’s and DOJ’s investigation. The settlement agreement involves a non-criminal In addition, there is a qui tam action pending in the U.S. District Court of the District of New Jersey related to the investigation by USAO NJ and DOJ. On September 18, 2017, Galena executed a settlement agreement with the attorneys for the relator in the qui tam action to settle the statutorily mandated attorney fees award by payment of $0.1 million in cash and $0.2 million in Galena common stock subject to court approval, which amounts were accrued during the second quarter 2017. Galena also obtained the consent of Private SELLAS under the terms of the Merger Agreement. However on November 7, 2017, attorneys for the qui tam relator agreed to have Galena pay the $0.2 million in cash. Galena also obtained the consent of Private SELLAS under the terms of the Merger Agreement. Galena paid the $0.3 million in cash for the statutorily mandated attorney fees award in the fourth quarter of 2017. As a result of receiving the portion of the civil settlement payment noted above and the settlement payment of the statutorily mandated attorney fees award, the relator will dismiss with prejudice the claims against Galena in the qui tam lawsuit. Open Matters On October 13, 2016, Galena filed a complaint in the Circuit Court for the County of Multnomah for the State of Oregon against Aon Risk Insurance Services West, Inc. (Aon) where Galena is seeking attorney’s fees, costs and expenses incurred by Galena related to its coverage dispute with a certain insurer and for amounts Galena was required to contribute to the settlements of In re Galena Biopharma, Inc. Derivative Litigation and In re Galena Biopharma, Inc. Securities Litigation as a direct result of certain insurer’s failure to pay its full policy limits of liability and other relief. Galena and Aon are currently engaged in written discovery. On February 13, 2017, a putative stockholder securities class action complaint was filed in the U.S. District Court for the District of New Jersey captioned, Miller v. Galena Biopharma, Inc., et al. On February 15, 2017, a putative stockholder securities class action complaint was filed in the U.S. District Court for the District of New Jersey entitled, Kattuah v. Galena Biopharma, Inc., et al. The actions assert that the defendants failed to disclose that Galena’s promotional practices for Abstral ® Subsequently, one of the stockholders groups withdrew its motion for lead plaintiff status and the individual stockholder notified the Court that he does not object to the appointment of the remaining stockholder group, GALE investor group, as lead plaintiff. On July 17, 2017, the Court approved the GALE investor group as named lead plaintiff and its counsel as lead and liaison counsel. The Court also consolidated both actions. An amended complaint was filed on October 6, 2017. On December 15, 2017, Galena and the former officers and employees filed a motion to dismiss the amended complaint. The plaintiffs have responded to a former officer’s motion to dismiss on February 13, 2018 and will respond to Galena’s and the other former officers’ and employees’ motion to dismiss on March 2, 2018. Galena and the former officers and employees are expected to file a reply in April of 2018. Thereafter, Galena will take the matter under advisement. It is not known when the Court will issue a ruling in this matter. On March 16, 2017, a complaint captioned Keller v. Ashton et al., CA No. 2:17-cv-01777 Galena also received a stockholder demand dated April 14, 2017, pursuant to 8 Del. C. Sec. 220, from a stockholder (Albert Zhang) demanding access to Galena’s books and records relating to its sales of Abstral and the U.S. Attorney’s investigation into Galena’s sale of Abstral in order for Mr. Zhang to determine, among other things, whether to file a derivative lawsuit against Galena’s former management and directors. Galena has responded to the demand and Mr. Zhang has indicated that he will file a derivative complaint soon. On April 27, 2017, a putative stockholder class action was filed in the Court of Chancery of the State of Delaware captioned Patel vs. Galena Biopharma, Inc. et. al, CA No. 2017-0325-JTL 2017-0423-JTL. no-action Under the terms of the settlement, the class will receive a settlement payment of $1.3 million, in addition to attorney fees in an amount to be approved by the Court. The settlement payment of $1.3 million consists of $50,000 in cash to be paid by the Company or its insurers and $1,250,000 in unrestricted shares of the Company’s common stock (“Settlement Stock”), which valuation will be based on the volume-weighted average closing price for the 20 trading days immediately preceding the day before the transfer of the Settlement Stock to the settlement fund pursuant to the terms and conditions of the settlement. The Company anticipates that the Settlement Stock will be issued, pursuant to the terms of the Stipulation of Settlement, in a transaction that is exempt from the registration requirements of the Securities Act of 1933, as amended (the “Securities Act”), pursuant to Section 3(a)(10) of the Securities Act. Any amounts awarded by the Court for attorneys’ fees will be paid in part by the settlement fund and in part by the Company’s insurance carriers. Upon the effectiveness of the proposed settlement, the individual defendants will be released from the claims that were asserted or could have been asserted in the class action by class members participating in the settlement. On July 6, 2017, a complaint captioned Jacob v. Schwartz et al., Case No. C17-01222, was filed in the Superior Court of California, County of Contra Costa against Galena’s former directors and the Company, as a nominal defendant. The complaint purports to assert derivative claims for breach of fiduciary duty on Galena’s behalf against its former directors based on substantially similar facts as alleged in the derivative complaint mentioned above. Galena’s response to the complaint was due on July 7, 2017; however, the Court on September 5, 2017, entered a stay of the proceedings pending resolution of motions to dismiss in the securities litigations described above. On November 7, 2017, a written demand was made on Galena by a stockholder requesting that additional financial projections and valuation analyses be made in Galena’s Form S-4 S-4. On January 23, 2018, a complaint captioned Johnson v Schwartz et al., CA No. 2:18-cv-00903 On or about April 9, 2018, JGB filed a lawsuit in the U.S. District Court for the Southern District of New York captioned JGB (Cayman) Newton, Ltd. v. Sellas Life Sciences Group, Inc., et al. Contingent Consideration related to Development, Regulatory and Commercial Milestone Payments and Business Combinations The Company acquires assets still in development and enters into research and development arrangements with third parties that often require milestone and royalty payments based on the progress of the asset through development stages. Milestone payments may be required, for example, upon approval of the product for marketing by a regulatory agency. In certain agreements, the Company is required to make royalty payments based upon a percentage of the sales. Because of the contingent nature of these payments, they are not included in the table of contractual obligations shown below. These arrangements may be material individually, and in the unlikely event that milestones for multiple products covered by these arrangements were reached in the same period, the aggregate charge to expense could be material to the results of operations. In addition, these arrangements often give the Company the discretion to unilaterally terminate development of the product, which would allow the Company to avoid making the contingent payments; however, the Company is unlikely to cease development if the compound successfully achieves clinical testing objectives. For additional information on the Company’s commitments under collaboration and license agreements read Note 6 to these consolidated financial statements. For additional information on the Company’s commitments of contingent consideration read Note 7 to these consolidated financial statements. Commitments The Company rents office space under a non-cancelable non-cancelable Operating 2018 $ 223 2019 76 Total $ 299

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Stockholders' Equity (Deficit)	11. Stockholders’ Equity (Deficit) On June 13, 2017, the Board of Directors approved the Bridge Financing, pursuant to which an aggregate of 1,865,262 shares were issued at a price per share equal to approximately $3.91. Under the same valuation terms as the Bridge Financing, the Company issued 38,321 shares to MSK in cancellation of a $0.2 million milestone payment due June 30, 2017, as contemplated by the MSK Side Letter. In addition, the Company issued 30,094 shares in cancellation of a $0.1 million Equilibria management fee that was payable for March to June 2017, and 28,246 shares in cancellation of net compensation of $0.1 million due to Dr. Angelos Stergiou (M.D., Sc.D. h.c.), the Company’s Chief Executive Officer. Shares of common stock as of December 31, 2017 for future issuance are reserved for as follows (in thousands): Warrants outstanding 963 Stock options outstanding 10 Restricted stock units 13 Options reserved for future issuance under the Company’s 2017 Equity Incentive Plan 575 Shares reserved for future issuance under the Employee Stock Purchase Plan 58 Total reserved for future issuance 1,619

Warrants

Warrants	12 Months Ended
	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Warrants	12. Warrants The following is a summary of warrant activity for the years ended December 31, 2017 (in thousands): Warrant Issuance Outstanding, Granted Assumed through Expired Outstanding, Expiration 2017 Equilibria — 316 — — 316 December 2022 Galena February 2017 — — 567 — 567 February 2022 Galena other — — 80 — 80 Various to 2022 — 316 647 — 963 Warrants assumed in connection with the acquisition of Galena consist of warrants that may be settled in cash, which are liability-classified warrants, and equity-classified warrants. Subsequent to December 31, 2017, 501,000 the Company’s February 2017 warrants to purchase shares of common stock were cancelled under various warrant exchange agreements as disclosed in Note 16. Warrants classified as liabilities Liability-classified warrants consist of warrants to purchase common stock issued in connection with previous equity financings for the February 2017 financing and various other equity financings (the Company) that were assumed by the Company at the consummation of the Merger. These warrants may settle in cash and were determined not to be indexed to the Company’s common stock. The estimated fair value of outstanding warrants accounted for as liabilities is determined at each balance sheet date. Any decrease or increase in the estimated fair value of the warrant liability since the most recent balance sheet date is recorded in the consolidated statement of operations as other income (expense). The fair value of the warrants as of December 31, 2017 is estimated using a Black-Scholes pricing model with the following inputs: Warrant Issuance Outstanding (in Strike price (per Expected term Volatility% Risk-free rate Galena February 2017 567 $ 33.00 4.12 79.29 % 2.09 % Galena other 76 $ 888.22 2.74 72.46 % 2.00 % The expected volatility assumptions are based on the Company’s implied volatility in combination with the implied volatilities of similar publicly traded entities. The expected term assumptions are based on the remaining contractual terms of the warrants. The risk-free rate is based on the zero-coupon The changes in fair value of the warrant liability for the year ended December 31, 2017 were as follows (in thousands): Warrant Issuance Warrant Fair value of Fair value of Change in fair Warrant Galena February 2017 $ — $ — $ 1,305 $ — $ 1,305 Galena other — — 4 — 4 $ — $ — $ 1,309 $ — $ 1,309 Warrants classified as equity The Company issued 316,163 warrants to purchase shares of the Company’s common stock at an exercise price of $7.42, maturing five years from issuance, to EQC Private Markets SAC Fund Ltd—EQC Biotech Sely I Fund on December 29, 2017. These warrants are recorded in equity at fair value upon issuance, and not as liabilities, and are not subject to adjustment to fair value in subsequent reporting periods. The fair value of the warrants granted was $5.60 per share using the Black-Scholes pricing model with the fair value assumptions for the grant including a volatility of 90.10%, expected term of five years, risk free rate of 2.20%, and a dividend rate of 0.00.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	13. Stock-Based Compensation Share and per share amounts below have been retroactively adjusted to reflect the exchange ratio and reverse stock split as described in Note 1. 2017 Equity Incentive Plan On December 29, 2017. the 2017 Equity Incentive Plan was approved, and currently allows for the issuance of up to a maximum of approximately 575,000 shares of common stock in connection with the grant of stock-based awards, including stock options, restricted stock, restricted stock units, stock appreciation rights and other types of awards as deemed appropriate, not including shares subject to awards assumed in connection with certain transactions, including the Merger. As of December 31, 2017, an aggregate of approximately 575,000 shares of common stock were reserved for issuance under the Company’s 2017 Equity Incentive Plan. Upon the consummation of the Merger, the Company assumed approximately 10,171 shares subject to outstanding common stock options granted under the Company’s 2016 Incentive Plan that will remain exercisable for one year for former Company employees and directors. There are approximately 575,000 shares available for future grants based on adjustments in the 2017 Equity Incentive Plan. There were no common stock options granted under the 2017 Equity Incentive Plan for the years ended December 31, 2017. The amount of shares reserved for issuance under the 2017 Equity Incentive Plan will automatically increase on January 1 st st st st st On November 1, 2016, the Board of Directors approved the Company’s 2016 Incentive Plan under which 189,627 shares were reserved for issuance. The 2017 Equity Incentive Plan replaced the 2016 Incentive Plan. In accordance with the 2016 Incentive Plan, the Company’s employees, directors and consultants are eligible to receive non-qualified and a 3-year period The following table summarizes the components of stock-based compensation expense in the consolidated statements of operations for the years ended December 31, 2017 and 2016, respectively (in thousands): 2017 2016 Research and development $ 729 $ 23 General and administrative 2,440 331 Total stock-based compensation $ 3,169 $ 354 Options to Purchase Shares of Common Stock There were no stock options granted during the year ended December 31, 2017. The weighted-average grant date fair value of options granted during the year ended December 31, 2016 was $38.03. The Company uses the Black-Scholes option-pricing model and the following assumptions were used to determine the fair value of all its stock options granted in 2016: Risk free interest rate 1.82-2.32% Volatility 85-94% Expected lives (years) 5.13-10.00 Expected dividend yield 0% As of December 31, 2017, there was no unrecognized compensation cost related to outstanding stock options. The following table summarizes stock option activity of the Company: Total Number of Shares (In Thousands) Weighted Average Exercise Price Aggregate Balance as of January 1, 2016 — $ — $ — Granted 55 $ 52.94 $ — Outstanding at December 31, 2016 55 $ 52.94 $ — Assumed in connection with the Merger with Galena 10 1,240.55 $ — Canceled (55 ) 52.94 $ — Outstanding at December 31, 2017 10 $ 1,240.55 $ — Options exercisable at December 31, 2017 10 $ 1,240.55 $ — The aggregate intrinsic values of outstanding and exercisable stock options at December 31, 2017 were calculated based on the closing price of the Company’s common stock as reported on the Nasdaq Capital Market on December 31, 2017 of $7.86 per share. The aggregate intrinsic value equals the positive difference between the closing fair market value of the Company’s common stock and the exercise price of the underlying stock options. Restricted Stock Units with Time-Based Conditions On August 7, 2017, the Board of Directors accelerated the vesting of all outstanding restricted stock units (“ RSUs”) with time-based conditions and all $1.2 million of unrecognized stock-based compensation was recognized upon acceleration. The following table outlines RSU activity with only a time-based condition: Total Number of Shares (In Thousands) Weighted Average Grant Date Fair Outstanding at January 1, 2016 — $ — Granted 46 $ 52.94 Outstanding at December 31, 2016 46 $ 52.94 Granted 58 $ 3.91 Vested (46 ) $ 52.94 Canceled (58 ) $ 3.91 Outstanding at December 31, 2017 — $ — RSUs with Time-Based and Performance-Based Conditions In addition to the RSUs with time-based conditions, the Company granted RSUs subject to both time-based and performance-based vesting conditions to certain of its employees and non-employees pursuant Total Number of Shares (In Thousands) Weighted Average Grant Date Fair Outstanding at January 1, 2016 — $ — Granted 21 $ 52.94 Outstanding at December 31, 2016 21 $ 52.94 Vested — NA Canceled (8 ) $ 52.94 Outstanding at December 31, 2017 13 $ 52.94 The Company recognizes compensation expense related to these RSUs when the liquidity event is deemed probable. As such, no compensation expense was recorded during the years ended December 31, 2017 and 2016, as the liquidity event is outside the Company’s control and not deemed probable until it occurs. 2017 Employee Stock Purchase Plan The Company also has an employee stock purchase plan (“ESPP”) which allows employees to contribute up to 15% of their cash earnings, subject to certain maximums, to be used to purchase shares of the Company’s common stock on each semi-annual purchase date. On each offering date, each eligible employee, pursuant to an offering made under the ESPP, will be granted a right to purchase up to that number of shares of Common Stock purchasable either with a percentage or with a maximum dollar amount, as designated by the Board, but in either case not exceeding fifteen percent (15%) of such employee’s earnings (as defined by the Board in each offering) during the period that begins on the offering date (or such later date as the Board determines for a particular offering) and ends on the date stated in the offering, which date will be no later than the end of the Offering. As of December 31, 2017, the board of directors has not established the various parameters under the ESPP and no shares have been delivered under the ESPP. There are approximately 57,000 shares of common stock reserved for issuance under the ESPP , plus the number of shares of common stock that are automatically added on January 1 st st st

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	14. Income Taxes The loss before income taxes is as follows (in thousands): As of December 31, 2017 2016 U.S. $ 265 $ 108 Non - U.S. (23,766 ) (17,788 ) $ (23,501 ) $ (17,680 ) The components of federal and state income tax expense are as follows (in thousands): As of December 31, 2017 2016 Current Federal $ 76 $ — State 138 42 Foreign — — Total current 214 42 Deferred expense Federal — — State 39 (41 ) Foreign — — Total deferred 39 (41 ) Total income tax expense $ 253 $ 1 The components of net deferred tax assets are as follows (in thousands): As of December 31, 2017 2016 Net operating loss carryforwards $ 1,028 $ 3,145 Tax credit carryforwards 345 295 Stock based compensation 2,550 28 Licensing deduction deferral 2,105 — Other 395 81 Gross deferred tax assets 6,423 3,549 Valuation allowance (4,658 ) (3,508 ) Net deferred tax asset $ 1,765 $ 41 The components of net deferred tax liabilities are as follows (in thousands): As of December 31, 2017 2016 In-process $ 3,438 $ — Gross deferred tax liability $ 3,438 $ — The provision for income taxes differs from the provision computed by applying the federal statutory rate to net loss before income taxes as follows: As of December 31, 2017 2016 U.S. federal statutory income tax rate (34.0 )% (34.0 )% State and local taxes, net of federal benefit 0.4 % — % Foreign rate differential 34.4 % 25.5 % Permanent differences 1.1 % 0.1 % Tax rate change and true-up 0.3 % — % Other 0.2 % — % Valuation allowance 0.1 % 10.4 % Tax credits (1.4 )% (2.0 )% Effective income tax rate 1.1 % 0.0 % At December 31, 2017, the Company had domestic federal and state net operating loss carryforwards of approximately $3.7 million and $3.7 million, respectively, available to reduce future taxable income, which expire at various dates beginning in 2027. The Company also had federal research and development tax credit carryforwards of approximately $0.4 million, respectively, available to reduce future tax liabilities and which expire at various dates beginning in 2027. The income tax expense for the year ended December 31, 2016 relates to both the indefinite lived deferred tax liabilities and the December 22, 2017 enactment of the Tax Cuts and Jobs Act. Under the provisions of the Internal Revenue Code, the net operating losses (“NOL”) and tax credit carryforwards are subject to review and possible adjustment by the Internal Revenue Service and state tax authorities. NOL and tax credit carryforwards may become subject to an annual limitation in the event of certain cumulative changes in the ownership interest of significant shareholders over a three-year period in excess of 50%, as defined under Sections 382 and 383 of the Internal Revenue Code of 1986, respectively, as well as similar state tax provisions. This could limit the amount of tax attributes that the Company can utilize annually to offset future taxable income or tax liabilities. The amount of the annual limitation, if any, will be determined based on the value of the Company immediately prior to the ownership change. Subsequent ownership changes may further affect the limitation in future years. The Company has completed several financings since its inception, which may have resulted in a change in control as defined by Sections 382 and 383 of the Internal Revenue Code or could result in a change in control in the future. Utilization of the net operating loss and tax credits carryforwards may be limited by “ownership change” rules, as defined in Section 382 of the Internal Revenue Code of 1986, as amended, and similar state provisions. This annual limitation may result in the expiration of the net operating losses and credits before utilization. In assessing the need for a valuation allowance the Company may utilize indefinite-lived deferred tax liabilities from an indefinite-lived intangible asset as a future source of income. The Company’s IPR&D, as recorded in acquisition accounting, can be utilized as a source of income arising from the future reversal of temporary difference that can be offset against post 2017 indefinite-lived NOLs. Therefore, the Company is permitted to offset the indefinite-lived DTL up to the 80 percent limitation for NOL’s generated subsequent to January 1, 2018. As such, an indefinite-lived NOL was recorded in acquisition accounting as a reduction to the valuation allowance related to deferred tax assets in the amount of $1.8 million. The valuation allowance increased by $1.2 million and $1.8 million for the years ended December 31, 2017 and 2016, respectively. The Company files income tax returns in the United States and various state jurisdictions. The Company is subject to tax examinations for the 2012 tax year and beyond. The Company does not recognize tax benefits that are not more-likely-than-not to be supported based upon the technical merits of the tax position taken. In assessing its unrecognized tax benefits, the Company has analyzed its tax return filing positions in all of the federal, state and foreign filing jurisdictions where it is required to file income tax returns, as well as all open years in those jurisdictions. The following table indicates the changes to the Company’s unrecognized tax benefits (in thousands): As of December 31, 2017 2016 Beginning of the Year - unrecognized tax benefits $ — $ — Increases/ (Decrease) - prior year tax positions 44 — Increases - current year tax positions 28 — End of the Year - unrecognized tax benefits $ 72 $ — The unrecognized tax benefits, if recognized and in absence of full valuation allowance, would impact the income tax provision by $28,000 and $44,000 as of December 31, 2017 and 2016, respectively. As of December 31, 2017, the Company does not believe that it is reasonably possible that its unrecognized tax benefits would significantly change in the following 12 months. In assessing the realizability of deferred tax assets, management considers whether it is more-likely-than-not that some portion or all of the deferred tax assets will not be realized in the near term. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. On December 22, 2017, the Tax Cuts and Jobs Act (the “2017 Tax Act”) was enacted. The 2017 Tax Act includes a number of changes to existing United States tax laws that impact the company, most notably a reduction of the United States corporate income tax rate from 34% to 21% for tax years beginning after December 31, 2017. The 2017 Tax Act also provides for a one-time transition tax on certain foreign earnings and the acceleration of depreciation for certain assets placed into service after September 27, 2017 as well as prospective changes beginning in 2018, including repeal of the domestic manufacturing deduction, acceleration of tax revenue recognition, capitalization of research and development expenditures, additional limitations on executive compensation and limitations on the deductibility of interest.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	15. Related Party Transactions Management and Strategic Collaboration Agreement Effective in June 2016, the Company and Equilibria, a company incorporated in Bermuda and a significant stockholder of the Company, entered into the management and strategic collaboration agreement. Under the Equilibria collaboration agreement, Equilibria, amongst other services, is engaged to provide certain strategic, management and capital raising advice to the Company. The Equilibria collaboration agreement is effective for three years and will be renewable thereafter only upon the mutual written agreement of both parties. The Equilibria collaboration agreement will automatically terminate upon the closing of an IPO or a strategic sale. During the term of the Equilibria collaboration agreement, the Company, in exchange for the services received, paid Equilibria a quarterly fee of $0.1 million (the “Equilibria Management Fee”). The Equilibria Management Fee can be paid in cash or, at the mutual agreement of the parties, in shares of the Company at a valuation equal to the Company’s most recent financing round. In addition to the Equilibria Management Fee, the Company has agreed to pay Equilibria any expenses reasonably incurred in performing the services agreed. For the years ended December 31, 2017 and 2016, the Company had incurred and paid in cash $0.3 million and $0.2 million, respectively, of Equilibria Management Fees. These amounts are included in general and administrative expense in the consolidated statements of operations. As of December 31, 2017, the Company had an outstanding payable of $0.1 million payable to Equilibria. As of December 31, 2016, there was no outstanding fee payable to Equilibria. For the provision of the management and strategic collaboration services, the Company also agreed to pay Equilibria an incentive fee equal to 2% of the post-money market value of the Company on the date of its IPO. Such fee will be payable in shares with a per-share In February 2017, the Company and Equilibria entered into an amendment of the Equilibria collaboration agreement. Under the amendment, in the event that the Company entered into a reverse merger transaction in lieu of an initial public offering, the incentive fee to Equilibria was 2% of the post-merger fully diluted market value of the Company immediately after the closing of the reverse merger transaction, payable in a combination of cash and shares of common stock of the Company. The cash payment was based on the per share price equaling the intrinsic value of the Company’s shares in the Merger. The share-based component of the incentive fee was based on the post-closing fully diluted number of shares outstanding. In August 2017, the Company and Equilibria further amended the Equilibria collaboration agreement to fix the compensation payable to Equilibria in connection with the completion of the Merger, described above in Note 1. Accordingly, upon consummation of the Merger on December 29, 2017, the Company incurred $0.1 million to Equilibria and issued 119,672 shares of common stock to Equilibria at a fair value of $0.9 million. These amounts are included in general and administrative expense in the consolidated statements of operations. Also, upon consummation of the Merger and pursuant to the amended Equilibria collaboration agreement, such agreement was terminated. Debt The Company has entered into several related party debt transactions with stockholders, which are described in Note 9. MSK License Agreement See Note 6 for information regarding the MSK License Agreement entered into by the Company. MSK owned 3.7% and 5.4% of the Company’s outstanding share capital as of December 31, 2017 and 2016, respectively. Other Related Party Transactions The Company’s Chief Executive Officer, Dr. Angelos M. Stergiou (M.D., Sc.D. h.c.) is a significant stockholder of the Company owning 7.8% and 24.0% of the Company’s outstanding share capital as of December 31, 2017 and 2016, respectively. Further transactions involving the Company and Dr. Stergiou are described in Note 6 and Note 9. On November 28, 2016, the Company granted 3,651 stock options to a prior member of the Company’s Board of Directors. Such prior director is additionally a full-time employee of MSK. The option was terminated on August 6, 2017 in consideration of an approximately $30,000 cash payment. On November 28, 2016, the Company granted 9,107 RSUs to a member of the Company’s Scientific Advisory Board pursuant to a consulting agreement for scientific advisory services to be performed on behalf of the Company (see Note 13). Additionally, such member and consultant is a full-time employee of MSK (see Note 6).

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	16. Subsequent Events Warrant Exchange Agreements On February 6, 2018, the Company and CVI Investments, Inc. (“CVI”) entered into a warrant exchange agreement (the “CVI Agreement”). The Company had previously issued to CVI a warrant to purchase 99,333 shares (on a post-reverse split basis) (the “CVI Warrant”) of its common stock, par value $0.0001 per share (the “Common Stock”) pursuant to the registered offering described in the Company’s prospectus filed with the Securities and Exchange Commission pursuant to Rule 424(b)(5) under the Securities Act of 1933 on February 9, 2017 (the “2017 Offering” and the warrants issued in such offering, the “2017 Warrants”). Pursuant to the CVI Agreement, in exchange for CVI’s agreement to surrender the CVI Warrant for cancellation, the Company agreed to issue to CVI a number of shares of Common Stock equal to the quotient resulting from dividing $232,440 by the closing sale price of the Common Stock on the first completed trading day following the first public announcement by the Company of the material terms and conditions of a Company financing transaction. The CVI Agreement contained a “Most Favored Nations” (“MFN”) clause, allowing CVI to opt to substitute terms of warrant exchange agreements entered with other warrant holders from the 2017 Offering if CVI deemed those terms more favorable. Pursuant to this MFN provision, effective as of March 1, CVI Agreement was deemed modified as follows: Pursuant to the CVI Agreement, in exchange for the surrender and cancellation of the CVI Warrants, the Company issued to CVI a convertible promissory note in the aggregate principal amount of $232,440.00 (the “CVI Note”). The CVI Note accrues interest on the outstanding principal amount at a rate of 5.0% per annum and the entire principal and accrued interest is due and payable on August 13, 2018. The interest rate increases to 18% per annum during a period in which there is an “event of default” under the CVI Note. The holder has the right, from time to time after April 30, 2018, to convert the outstanding principal and accrued interest into shares of Common Stock at a conversion price equal to $7.00 per share (subject to adjustments for stock splits, combinations and the like) (the “Conversion Price”), provided that CVI may not affect any such conversions to the extent it would beneficially own in excess of 4.99% of the Company’s outstanding Common Stock. At any time after an event of default has occurred (whether or not the Company has cured such default), CVI may elect to convert the outstanding principal and accrued interest into shares of Common Stock at an alternate conversion price equal to the lower of (i) the Conversion Price then in effect at the time of such conversion, or (ii) 70% of the lowest VWAP of the Common Stock on a trading day during the 10-trading period prior to such conversion. For purposes of the CVI Note, an “event of default” is deemed to have occurred upon (A) the suspension of trading of the Common Stock on the Nasdaq Capital Market for a period of five consecutive trading days, (B) the Company’s failure to timely deliver shares of Common Stock upon a conversion within five trading days of the applicable conversion date or upon the Company’s notice that it does not intend to comply a request by Empery to convert, (C) the Company’s or any of its subsidiaries’ failure to timely pay any amount due under the CVI Note or the CVI Agreement, (D) the Company’s bankruptcy, insolvency, liquidation, or similar proceeding, or (E) a breach by the Company of any representation, warranty or covenant contained in the CVI Note or the CVI Agreement that remains uncured for a period of three consecutive trading days. On April 2, 2018, the Company and CVI mutually agreed to waive the April 30, 2018 start date for the conversion right of the CVI Note, and CVI converted the entire outstanding balance of principal and interest on the CVI Note into 33,356 shares of Company’s Common Stock. As a result, the CVI Note is fully paid. On February 7, 2018, the Company entered into a warrant exchange agreement (the “Anson Agreement”) with Anson Investments Master Fund LP (“Anson”). The Company previously issued to Anson a warrant to purchase 30,000 shares (on a post-reverse split basis) of Common Stock (the “Anson Warrant”) in the 2017 Offering. Pursuant to the Anson Agreement, on February 8, 2018, the Company issued to Anson Investments 12,536 shares of Common Stock in exchange for the surrender and cancellation of the Anson Warrant. On February 9, 2018, the Company entered into a warrant exchange agreement (the “Sabby Agreement”) with Sabby Healthcare Master Fund Ltd. and Sabby Volatility Warrant Master Fund Ltd (collectively, “Sabby”). The Company had previously issued to Sabby warrants to purchase an aggregate of 83,333 shares (on a post-reverse split basis) of Common Stock (the “Sabby Warrants”) pursuant to the 2017 Offering. Pursuant to the Sabby Agreement, in exchange for the surrender and cancellation of the Sabby Warrants, the Company will issue to Sabby a number of shares of Common Stock determined by dividing $195,000 by the closing sale price of the Common Stock on the date of the closing date of the exchange. Such closing is expected to occur on or before February 13, 2018, and the Sabby Agreement will terminate if such closing does not occur by such date. The Sabby Agreement also provides that during the 30-trading Also on February 9, 2018, the Company entered into a warrant exchange agreement (the “Hudson Bay Agreement”) with Hudson Bay Master Fund Ltd (“Hudson Bay”). The Company had previously issued to Hudson Bay a warrant to purchase an aggregate of 146,666 shares (on a post-reverse split basis) of Common Stock (the “Hudson Bay Warrant”) pursuant to the 2017 Offering. Pursuant to the Hudson Bay Agreement, in exchange for the surrender and cancellation of the Hudson Bay Warrant, the Company issued to Hudson Bay a convertible promissory note in the principal amount of $343,200 (the “Hudson Bay Note”). The Hudson Bay Agreement also provides that provides that if the Company enters into an agreement with a holder of the 2017 Warrants that provides for the exchange of such warrants on terms more favorable than those contained in the Hudson Bay Agreement, including without limitation, with respect to ratio of any cash paid, or principal amount of notes or value of Common Stock paid in exchange for such warrants, then the Company is to provide notice to Hudson Bay within one trading day of such agreement and the terms of the Hudson Bay Agreement will be deemed to have been modified in an economically and legally equivalent manner such that Hudson Bay would receive the benefit of such more favorable terms, unless Hudson Bay elects not to accept such terms by a notice delivered to the Company within 10 trading days. The Hudson Bay Note accrues interest on the outstanding principal amount at a rate of 5% per annum and the entire principal and accrued interest is due and payable on August 9, 2018. The interest rate increases to 18% per annum during a period in which there is an “event of default” under the Hudson Bay Note. The holder has the right, from time to time after April 30, 2018, to convert the outstanding principal and accrued interest into shares of Common Stock at a conversion price equal to $7.00 per share (subject to adjustments for stock splits, combinations and the like) (the “Conversion Price”), provided that Hudson Bay may not affect any such conversions to the extent it would beneficially own in excess of 9.99% of the Company’s outstanding Common Stock. At and any time after an event of default has occurred (whether or not the Company has cured such default), Hudson Bay may elect to convert the outstanding principal and accrued interest into shares of Common Stock at an alternate conversion price equal to the lower of (i) the Conversion Price then in effect at the time of such conversion, or (ii) 70% of the lowest volume-weighted average price of the Common Stock on a trading day during the 10-trading On February 13, 2018, the Company and Alto Opportunity Master Fund, SPC – Segregated Master Portfolio B (“Alto”) entered into a warrant exchange agreement (the “Alto Agreement”). The Company had previously issued to Alto a warrant to purchase 106,667 shares (on a post-reverse split basis) (the “Alto Warrant”) of its Common Stock pursuant to the 2017 Offering. Pursuant to the Alto Agreement, in exchange for Alto’s agreement to surrender the Alto Warrant for cancellation, the Company agreed to issue to Alto a number of shares of Common Stock equal to the quotient resulting from dividing $249,600 by the closing sale price of the Common Stock on the closing date of the exchange. Pursuant to the Alto Agreement, on February 15, 2018, the Company issued to Alto 45,464 shares of Common Stock in exchange for the surrender and cancellation of the Alto Warrant. The Alto Agreement contained a MFN clause, allowing Alto to opt to substitute terms of Warrant Exchange Agreements entered with other warrant holders from the 2017 Offering if Alto deemed those terms more favorable. Pursuant to this MFN clause, effective as of February 13, 2018, shares previously issued to Alto under the Alto Agreement were returned/cancelled and the Alto Agreement was deemed modified as follows: Pursuant to the Alto Agreement, in exchange for the surrender and cancellation of the Alto Warrants, the Company issued to Alto a convertible promissory note in the aggregate principal amount of $249,600.00 (the “Alto Note”). The Alto Note accrues interest on the outstanding principal amount at a rate of 5.0% per annum and the entire principal and accrued interest is due and payable on August 13, 2018. The interest rate increases to 18% per annum during a period in which there is an “event of default” under the Alto Note. The holder has the right, from time to time after April 30, 2018, to convert the outstanding principal and accrued interest into shares of Common Stock at the Conversion Price provided that Alto may not affect any such conversions to the extent it would beneficially own in excess of 9.99% of the Company’s outstanding Common Stock. At any time after an event of default has occurred (whether or not the Company has cured such default), Alto may elect to convert the outstanding principal and accrued interest into shares of Common Stock at an alternate conversion price equal to the lower of (i) the Conversion Price then in effect at the time of such conversion, or (ii) 70% of the lowest volume-weighted average price of the Common Stock on a trading day during the 10-trading period prior to such conversion. For purposes of the Alto Note, an “event of default” is deemed to have occurred upon (A) the suspension of trading of the Common Stock on the Nasdaq Capital Market for a period of five consecutive trading days, (B) the Company’s failure to timely deliver shares of Common Stock upon a conversion within five trading days of the applicable conversion date or upon the Company’s notice that it does not intend to comply a request by Empery to convert, (C) the Company’s or any of its subsidiaries’ failure to timely pay any amount due under the Alto Note or the Alto Agreement, (D) the Company’s bankruptcy, insolvency, liquidation, or similar proceeding, or (E) a breach by the Company of any representation, warranty or covenant contained in the Alto Note or the Alto Agreement that remains uncured for a period of three consecutive trading days. On April 2, 2018, the Company and Alto mutually agreed to waive the April 30, 2018 start date for the conversion right of the Alto Note, and Alto converted the entire outstanding balance of principal and interest on the Alto Note into 35,998 shares of Company’s Common Stock. As a result, the Alto Note is fully paid. On February 14, 2018, the Company entered into a warrant exchange agreement (the “Lincoln Park Agreement”) with Lincoln Park Capital Fund LLC (“Lincoln Park”). The Company previously issued to Lincoln Park a warrant to purchase 8,333 shares (on a post-reverse split basis) of Common Stock (the “Lincoln Park Warrant”) in the 2017 Offering. Pursuant to the Lincoln Park Agreement, on February 19, 2018, the Company issued to Lincoln Park Capital 3,421 shares of Common Stock in exchange for the surrender and cancellation of the Lincoln Park Warrant. On February 22, 2018, the Company entered into a warrant exchange agreement (the “Empery Agreement”) with Empery Asset Master Ltd., Empery Tax Efficient, LP and Empery Tax Efficient II, LP (collectively, “Empery”). The Company had previously issued to Empery warrants to purchase an aggregate of 26,668 shares (on a post-reverse split basis) (the “Empery Warrants”) of its common stock, par value $0.0001 per share (the “Common Stock”) pursuant to the registered offering described in the Company’s prospectus filed with the Securities and Exchange Commission pursuant to Rule 424(b)(5) under the Securities Act of 1933 on February 9, 2017 (the “2017 Offering” and the warrants issued in such offering, the “2017 Warrants”). Pursuant to the Empery Agreement, in exchange for the surrender and cancellation of the Empery Warrants, the Company issued to Empery convertible promissory notes in the aggregate principal amount of $64,403.12 (the “Empery Notes”). The Empery Agreement also provides that if the Company enters into an agreement with a holder of the 2017 Warrants that provides for the exchange of such warrants on terms more favorable than those contained in the Empery Agreement, including without limitation, with respect to ratio of any cash paid, or principal amount of notes or value of Common Stock paid in exchange for such warrants, then the Company is to provide notice to Empery within one trading day of such agreement and the terms of the Empery Agreement will be deemed to have been modified in an economically and legally equivalent manner such that Empery would receive the benefit of such more favorable terms, unless Empery elects not to accept such terms by a notice delivered to the Company within 10 trading days. The Empery Notes accrue interest on the outstanding principal amount at a rate of 4.75% per annum and the entire principal and accrued interest is due and payable on August 22, 2018. The interest rate increases to 18% per annum during a period in which there is an “event of default” under the Empery Notes. The holder has the right, from time to time after April 30, 2018, to convert the outstanding principal and accrued interest into shares of Common Stock at the Conversion Price, provided that Empery may not affect any such conversions to the extent it would beneficially own in excess of 9.99% of the Company’s outstanding Common Stock. At any time after an event of default has occurred (whether or not the Company has cured such default), Empery may elect to convert the outstanding principal and accrued interest into shares of Common Stock at an alternate conversion price equal to the lower of (i) the Conversion Price then in effect at the time of such conversion, or (ii) 70% of the lowest volume-weighted average price of the Common Stock on a trading day during the 10-trading The Company’s entry into each of the warrant exchange agreements were the result of separate private negotiations between the Company and each of the named companies. Series A Convertible Preferred On March 7, 2018, the Company entered into a Securities Purchase Agreement with investors, pursuant to which the Company agreed to sell to the Investors, in a private placement pursuant to Rule 4(a)(2) and Regulation S under the Securities Act of 1933, as amended, an aggregate of 10,700 shares of the Company’s newly-created non-voting At the first closing of the Series A Convertible Preferred on March 9, 2018, the Company issued an aggregate 5,987 shares of Series A Convertible Preferred and 774,186 Warrants for aggregate gross proceeds of $5,987,000. The second closing of the remaining 4,713 shares of the Series A Convertible Preferred and 609,445 shares of common stock, for aggregate gross proceeds of $4,713,000 will occur within five business days of receipt of necessary stockholder approval under the applicable rules and regulations of the Nasdaq Stock Market LLC. Under the Series A Convertible Preferred, the Company is obligated to seek stockholder approval no later than May 7, 2018 (within 60 days of the date of the Series A Convertible Preferred), and will file proxy materials with the U.S. Securities and Exchange Commission in connection therewith. The Company’s directors, executive officers and beneficial owners of more than 10% of the Company’s common stock, who collectively hold more than 50% of the Company’s outstanding voting power, entered into voting agreements dated March 9, 2018, pursuant to which they agreed to vote in favor of any resolution presented to the stockholders of the Company to approve the issuance, in the aggregate, of greater than 19.99% of the common stock outstanding prior to the entry into the Series A Convertible Preferred, for less than the greater of the book or market value of the common stock as required by the listing rules of The Nasdaq Stock Market. In addition, such persons also entered into lock-up Qualified Offering is defined in the purchase agreement and the Certificate of Designation (as defined below) as a public offering raising aggregate gross proceeds of no less than $20.0 million. In the event of a Qualified Offering, under the Series A Convertible Preferred, investors have the right to acquire the securities sold in such Qualified Offering by converting their shares of Series A Convertible Preferred into the same securities on a $1.00 for $1.00 basis based on the stated value of their shares of Series A Convertible Preferred. Series A Convertible Preferred Shares of Series A Convertible Preferred are convertible into common stock at the option the holder from time to time. Prior to receipt of stockholder approval, such conversion is limited to an Investor’s pro rata The initial conversion price is $5.80 per share of common stock, subject to standard adjustments for certain transactions affecting the Company’s securities (such as stock dividends, stock splits, and the like). Until consummation of a Qualified Offering, such conversion price is also subject to anti-dilution price protection in the event of non-exempt The Series A Convertible Preferred generally have no voting rights. However, for so long as any shares of Series A Convertible Preferred are outstanding, the affirmative vote of the holders of a majority of the then outstanding shares of the Series A Convertible Preferred is required to: (a) alter or change adversely the powers, preferences or rights given to the Series A Convertible Preferred or alter or amend the Certificate of Designation, (b) authorize or create any class of stock ranking as to dividends, redemption or distribution of assets upon a Liquidation (as defined in the Certificate of Designation) senior to, or otherwise pari passu Upon any liquidation, dissolution or winding-up pari passu Warrants Placement Agent out-of-pocket Neuvax Phase 2b Clinical Trial On April 2, 2018 and in connection with the Company’s single-blinded, controlled Phase 2b independent investigator-sponsored clinical trial of Herceptin: Genentech/Roche) +/- NeuVax in HER2 1+/2+ breast cancer patients, we announced the interim efficacy analysis, conducted by an independent Data Safety Monitoring Board of the efficacy and safety data for the study in an overall population of 275 patients as well as the two primary study target patient populations (node-positive and triple negative breast cancer (“TNBC”)) after a median follow-up of 19 months, demonstrated a clinically meaningful difference in median disease-free survival in favor of the active arm (NeuVax + Herceptin), a primary endpoint of the study, with hazard ratios of 0.67 and 0.61 in the intent to treat and modified intent to treat populations (i.e., those who received at least one dose of vaccine or control) as well as a 34.9% and 39.5% reduction in relative risk of recurrence in the active versus control arms in the intent to treat and modified intent to treat populations, respectively. A clinically meaningful and also statistically significant difference was found between the two arms in the cohort of patients (n= 98) with TNBC, with a hazard ratio of 0.26 and a p-value of 0.023 in favor of the NeuVax + Herceptin combination. Similarly, a clinically meaningful and statistically significant difference was found between the two arms in favor of the combination in the cohort of patients not receiving hormonal therapy (n = 110), with a hazard ratio of 0.24 and a p-value of 0.009. This pre-specified interim analysis also showed an adverse event profile with no notable differences between treatment arms. This analysis confirmed the 2016 data showing that the addition of NeuVax to Herceptin did not result in any additional cardiotoxicity compared to Herceptin alone. Based on these results, and the independent Data Safety Monitoring Board’s recommendation, the Company plans to expeditiously seek regulatory guidance by the FDA for further development of the combination of NeuVax + Herceptin in TNBC, considering the statistically significant benefit of the combination therapy seen in this population with large unmet medical need. JGB Action On or about April 9, 2018, JGB filed a lawsuit in the U.S. District Court for the Southern District of New York captioned JGB (Cayman) Newton, Ltd. v. Sellas Life Sciences Group, Inc., et al.

Basis of Presentation and Sum23

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”). Any reference in these notes to applicable guidance is meant to refer to U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”).
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the financial statements of the Company and its wholly owned subsidiaries, SELLAS Bermuda, SELLAS Life Sciences Group UK Ltd (“SELLAS UK”), Apthera, Inc. (“Apthera”) and Mills Pharmaceuticals, LLC (“Mills”). All significant intercompany accounts and transactions have been eliminated upon consolidation.
Use of Estimates	Use of Estimates The preparation of these consolidated financial statements in accordance with U.S. 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 financial statements and the reported amounts of expenses during the reporting period. On an ongoing basis, the Company evaluates its estimates using historical experience and other factors, including the current economic environment. Significant items subject to such estimates are assumptions used for purposes of determining stock-based compensation, the fair value of the warrants, beneficial conversion features associated with convertible notes, fair value of intangible assets acquired, carrying value of goodwill, fair value of contingent purchase price consideration, fair value of deferred tax liability assumed and accounting for research and development activities. Management believes its estimates to be reasonable under the circumstances. Actual results could differ significantly from those estimates.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of the Company’s financial instruments, including cash equivalents, accounts payable, and accrued expenses approximate fair value due to the short-term nature of those instruments. The carrying amounts of the Company’s outstanding convertible notes approximate fair value due to the debt carrying a variable interest rate that is tied to the current London Interbank Offer Rate (“LIBOR”) rate. The fair value of the convertible notes is determined using a binomial lattice model that utilizes certain unobservable inputs that fall within Level 3 of the fair value hierarchy. The fair value of the warrants is determine using a Black-Scholes pricing model.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist principally of cash on deposit with multiple financial institutions, the balances of which frequently exceed federally insured limits.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers any highly liquid investments, such as money market funds, with an original maturity of three months or less to be cash and cash equivalents.
Restricted Cash and Cash Equivalents	Restricted Cash and Cash Equivalents Restricted cash consists of the minimum cash covenant as required by the debenture and certificates of deposit on hand with the Company’s financial institutions as collateral for its corporate credit cards.
Intangible Assets	Intangible Assets Intangible assets are comprised of identifiable in-process written-off non-cash
Goodwill	Goodwill Goodwill is the excess of the cost of an acquired entity over the net amounts assigned to tangible and intangible assets acquired and liabilities assumed. Goodwill is not amortized but is subject to an annual impairment test. The Company has a single reporting unit and all goodwill relates to that reporting unit. The Company performs its annual goodwill impairment test at the reporting unit level on October 1 of each fiscal year or more frequently if changes in circumstances or the occurrence of events suggest that an impairment exists. Goodwill is evaluated for impairment using the simplified test of goodwill impairment as defined by the FASB Accounting Standards Update No. 2017-04.
Severance Costs	Severance Costs The Company recognized and paid $1.9 million of exit costs during 2017 related to severance benefits for former Galena employees terminated immediately prior to the consummation of the Merger.
Patents and Patent Application Costs	Patents and Patent Application Costs Although the Company believes that its patents and underlying technology have continuing value, the amount of future benefits to be derived from the patents is uncertain. Patent costs are, therefore, expensed as incurred.
Legal Fees and Insurance Recoveries	Legal Fees and Insurance Recoveries There can be a significant time lag between the time that legal fees are incurred and the insurance reimbursement available to offset the related costs. The legal fees are recorded in the period they are incurred, and the insurance recoveries for those costs are recorded in the period when the insurance reimbursement is deemed probable.
Stock-based Compensation	Stock-based Compensation The Company follows the provisions of the FASB ASC Topic 718, “ Compensation — Stock Compensation” non-employee For stock options and warrants granted as consideration for services rendered by non-employees, 505-50 505-50”), Equity Based Payments to Non- Non-employee re-measured non-cash non-employees re-measurements
Research and Development Expenses	Research and Development Expenses Research and development costs are expensed as incurred. Research and development costs that are paid in advance of performance are capitalized as a prepaid expense and amortized over the service period as the services are provided. Clinical study costs, a component of research and development expenses, are accrued over the service periods specified in the contracts and adjusted as necessary based on an ongoing review of the level of effort and costs actually incurred. Payments for a product license prior to regulatory approval of the product and payments for milestones achieved prior to regulatory approval of the product are expensed in the period incurred as research and development expenses. Milestone payments made in connection with regulatory approvals are capitalized and amortized to cost of revenue over the remaining useful life of the asset. Research and development expenses primarily consist of the intellectual property and research and development materials acquired, expenses from third parties who conduct research and development activities on behalf of the Company as well as related wages, benefits and other operating costs. The Company expenses in-process research and development projects acquired as asset acquisitions which have not reached technological feasibility and which have no alternative future use.
Income Taxes	Income Taxes The Company uses the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The Company recognizes the benefit of an uncertain tax position that it has taken or expects to take on its income tax return it files, if such a position is more likely than not to be sustained. The Company recognizes liabilities or assets for the deferred tax consequences of temporary differences between the tax basis of assets or liabilities and their reported amounts in the financial statements in accordance with FASB ASC 740-10, Accounting for Income Taxes” (“ASC 740-10”). ASC 740-10 On December 22, 2017 the President of the United States signed into law the Tax Cuts and Jobs Act (“The 2017 Tax Act”). This legislation makes significant changes in the United States tax laws including, but not limited to, reducing the corporate tax rate to 21% starting in 2018. The 2017 Tax Act required the Company to revalue its deferred tax assets and liabilities to the new rate of 21%. For the years ended December 31, 2017 and 2016, the Company recognized income tax expense of $253,000 and $1,000, respectively. Staff Accounting Bulletin No. 118 (“SAB 118”) was issued to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Act. In accordance with SAB 118, we determined that the adjustment to deferred taxes was a provisional amount and a reasonable estimate at December 31, 2017. We do not expect any impact on recorded deferred tax balances as the remeasurement of net deferred tax assets will be offset by a change in valuation allowance. We are analyzing certain aspects of the Tax Act which could potentially affect the remeasurement of the net deferred tax assets.
Net Loss Per Share	Net Loss Per Share Basic loss per share is computed by dividing net loss applicable to common stockholders by the weighted average number of shares of common stock outstanding during each period. Diluted loss per share includes the effect, if any, from the potential exercise or conversion of securities, such as convertible debt, warrants, stock options and unvested restricted stock that would result in the issuance of incremental shares of common stock. In computing the basic and diluted net loss per share, the weighted average number of shares remains the same for both calculations due to the fact that when a net loss exists, dilutive shares are not included in the calculation as the impact is anti-dilutive. The following potentially dilutive securities outstanding have been excluded from the computation of diluted weighted average shares outstanding, as they would be anti-dilutive: Year ended December 31, 2017 2016 Common stock warrants 963 — Stock options 10 55 Unvested restricted stock awards 13 67 986 122 Amounts in the table reflect the common stock equivalents of the noted instruments.
Comprehensive Loss	Comprehensive Loss The Company has no items of comprehensive income or loss other than net loss.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In July 2017, the FASB issued ASU 2017-11, Earnings Per Share (Topic 260); Distinguishing Liabilities from Equity (Topic 480); Derivatives and Hedging (Topic 815): (Part I) Accounting for Certain Financial Instruments with Down Round Features, (Part II) Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception. In May 2017, the FASB issued Accounting Standard Update No. 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting 2017-09 In November 2016, the FASB issued ASU No. 2016-18, Restricted cash In March 2016, the FASB issued Accounting Standards Update 2016-09, Compensation-Stock Compensation 2016-09 2016-09 In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases right-of-use

Organization and Description 24

Organization and Description of Business (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Adjustments to Additional Paid-in Capital	Common stock as included in the consolidated statement of stockholders’ equity (deficit) was adjusted to reflect the $0.0001 par value per share and additional paid-in capital was adjusted as follows (in thousands): 2016 Retroactive 2016 Revised Balance at January 1, 2016 $ 288 $ 200 $ 488 Shares issued as partial consideration of MSK license fees 897 3 900 Shares issued pursuant to MSK license agreement 1,967 9 1,976 Shares issued in cancellation of Clarendon license agreement 500 2 502 Shares issued upon conversion of 2016 convertible note 15,357 54 15,411 Shares issued in cancellation of long-term debt 5,783 20 5,803 Stock-based compensation 354 — 354 Balance at December 31, 2016 $ 25,146 $ 288 $ 25,434

Basis of Presentation and Sum25

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Potentially Dilutive Securities Outstanding Excluded from Computation of Diluted Weighted Average Shares Outstanding	The following potentially dilutive securities outstanding have been excluded from the computation of diluted weighted average shares outstanding, as they would be anti-dilutive: Year ended December 31, 2017 2016 Common stock warrants 963 — Stock options 10 55 Unvested restricted stock awards 13 67 986 122

Business Combination (Tables)

Business Combination (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Summary of Purchase Price	The purchase price was calculated as follows (in thousands): Fair value of the Company’s pre-Merger $ 12,487 Estimated fair value of the Company’s per-Merger 32 Total purchase price $ 12,519
Total Purchase Price Allocation	The following table summarizes the allocation of the purchase price to the assets acquired and liabilities assumed as of the acquisition date (in thousands): Assets acquired: Cash $ 1,812 Restricted cash 10,346 Prepaid expenses and other assets 3,103 Intangible assets 17,600 Goodwill 1,914 Total assets acquired $ 34,775 Liabilities assumed: Accounts payable and accrued expenses $ 5,692 Litigation settlement 1,300 Long-term debt 10,988 Contingent purchase price consideration of Apthera, Inc. 1,294 Warrant liability 1,309 Deferred tax liability 1,673 Total liabilities assumed $ 22,256 Net assets acquired $ 12,519
Schedule of Pro forma Consolidated Financial Information	Pro forma consolidated financial information for 2017 and 2016 (unaudited): Year ended December 31, 2017 2016 Net revenues (in thousands) $ — $ — Net loss (in thousands) $ 24,089 $ 28,389 Basic and diluted net loss per share $ 5.15 $ 8.61

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill	Changes in the carrying amount of goodwill for the period ended December 31, 2017 consisted of the following (in thousands): Balance as of January 1, 2017 $ — Goodwill as a result of the Merger 1,914 Balance as of December 31, 2017 $ 1,914

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, All Other Investments [Abstract]
Contingent Purchase Price Consideration, Convertible Debt, Measured at Estimated Fair Value on Recurring Basis	The following tables present information about the Company’s assets and liabilities measured at fair value on a recurring basis in the consolidated balance sheets (in thousands): Description December 31, Quoted Prices In Significant Other Unobservable Assets: Cash equivalents $ 1,662 $ 1,662 $ — $ — Restricted cash equivalents 10,245 10,245 — — Total assets measured and recorded at fair value $ 11,907 $ 11,907 $ — $ — Liabilities: Warrants potentially settleable in cash $ 1,309 $ — $ — $ 1,309 Contingent consideration 1,294 — — 1,294 Total liabilities measured and recorded at fair value $ 2,603 $ — $ — $ 2,603

Accrued Expenses and Other Cu29

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): Year Ended December 31, 2017 2016 Professional fees $ 1,744 $ 1,077 Value added tax 426 — Rebates and returns 223 — Compensation and related benefits 566 249 Clinical trial costs 51 2,496 Other 191 227 Accrued expenses and other current liabilities $ 3,201 $ 4,049

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Debt and Convertible Debt	Debt and convertible debt consist of the following (in thousands): Year Ended December 31, 2017 2016 Debt Current portion of Senior Secured Debenture $ 8,377 $ — Non-current portion of Senior Secured Debenture 2,611 — Total debt $ 10,988 $ — Convertible debt 2015 Shareholder Notes $ — $ 1,709 2015 Sely Note — 5,659 Total convertible debt $ — $ 7,368

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Summary of Contractual Obligations Under Non-cancelable Operating Lease	The Company’s contractual obligations that may require future cash payments as of December 31, 2017 under the non-cancelable Operating 2018 $ 223 2019 76 Total $ 299

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit) (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Common Stock are Reserved for Future Issuance	Shares of common stock as of December 31, 2017 for future issuance are reserved for as follows (in thousands): Warrants outstanding 963 Stock options outstanding 10 Restricted stock units 13 Options reserved for future issuance under the Company’s 2017 Equity Incentive Plan 575 Shares reserved for future issuance under the Employee Stock Purchase Plan 58 Total reserved for future issuance 1,619

Warrants (Tables)

Warrants (Tables)	12 Months Ended
	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Schedule of Warrant Activity	The following is a summary of warrant activity for the years ended December 31, 2017 (in thousands): Warrant Issuance Outstanding, Granted Assumed through Expired Outstanding, Expiration 2017 Equilibria — 316 — — 316 December 2022 Galena February 2017 — — 567 — 567 February 2022 Galena other — — 80 — 80 Various to 2022 — 316 647 — 963
Fair Value of Warrants is Estimated Using Black-Scholes Option Pricing Model	The fair value of the warrants as of December 31, 2017 is estimated using a Black-Scholes pricing model with the following inputs: Warrant Issuance Outstanding (in Strike price (per Expected term Volatility% Risk-free rate Galena February 2017 567 $ 33.00 4.12 79.29 % 2.09 % Galena other 76 $ 888.22 2.74 72.46 % 2.00 %
Changes in Fair Value of Warrant Liability	The changes in fair value of the warrant liability for the year ended December 31, 2017 were as follows (in thousands): Warrant Issuance Warrant Fair value of Fair value of Change in fair Warrant Galena February 2017 $ — $ — $ 1,305 $ — $ 1,305 Galena other — — 4 — 4 $ — $ — $ 1,309 $ — $ 1,309

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Allocated Stock-based Compensation Expense	The following table summarizes the components of stock-based compensation expense in the consolidated statements of operations for the years ended December 31, 2017 and 2016, respectively (in thousands): 2017 2016 Research and development $ 729 $ 23 General and administrative 2,440 331 Total stock-based compensation $ 3,169 $ 354
Assumptions for Option Grants Issued	The Company uses the Black-Scholes option-pricing model and the following assumptions were used to determine the fair value of all its stock options granted in 2016: Risk free interest rate 1.82-2.32% Volatility 85-94% Expected lives (years) 5.13-10.00 Expected dividend yield 0%
Stock Option Activity	The following table summarizes stock option activity of the Company: Total Number of Shares (In Thousands) Weighted Average Exercise Price Aggregate Balance as of January 1, 2016 — $ — $ — Granted 55 $ 52.94 $ — Outstanding at December 31, 2016 55 $ 52.94 $ — Assumed in connection with the Merger with Galena 10 1,240.55 $ — Canceled (55 ) 52.94 $ — Outstanding at December 31, 2017 10 $ 1,240.55 $ — Options exercisable at December 31, 2017 10 $ 1,240.55 $ —
RSU Activity for RSUs with Only Time-Based Conditions	The following table outlines RSU activity with only a time-based condition: Total Number of Shares (In Thousands) Weighted Average Grant Date Fair Outstanding at January 1, 2016 — $ — Granted 46 $ 52.94 Outstanding at December 31, 2016 46 $ 52.94 Granted 58 $ 3.91 Vested (46 ) $ 52.94 Canceled (58 ) $ 3.91 Outstanding at December 31, 2017 — $ —
RSU Activity for RSUs with Both Time-Based and Performance-Based Conditions	The liquidity event, as defined in the relevant RSU grant agreements, will be satisfied upon the earlier of either: a) change of control or b) a qualified initial public offering. Total Number of Shares (In Thousands) Weighted Average Grant Date Fair Outstanding at January 1, 2016 — $ — Granted 21 $ 52.94 Outstanding at December 31, 2016 21 $ 52.94 Vested — NA Canceled (8 ) $ 52.94 Outstanding at December 31, 2017 13 $ 52.94

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Loss Before Income Taxes	The loss before income taxes is as follows (in thousands): As of December 31, 2017 2016 U.S. $ 265 $ 108 Non - U.S. (23,766 ) (17,788 ) $ (23,501 ) $ (17,680 )
Summary of Components of Federal and State Income Tax Expense	The components of federal and state income tax expense are as follows (in thousands): As of December 31, 2017 2016 Current Federal $ 76 $ — State 138 42 Foreign — — Total current 214 42 Deferred expense Federal — — State 39 (41 ) Foreign — — Total deferred 39 (41 ) Total income tax expense $ 253 $ 1
Summary of Components of Net Deferred Tax Assets	The components of net deferred tax assets are as follows (in thousands): As of December 31, 2017 2016 Net operating loss carryforwards $ 1,028 $ 3,145 Tax credit carryforwards 345 295 Stock based compensation 2,550 28 Licensing deduction deferral 2,105 — Other 395 81 Gross deferred tax assets 6,423 3,549 Valuation allowance (4,658 ) (3,508 ) Net deferred tax asset $ 1,765 $ 41
Summary of Components of Net Deferred Tax Liabilities	The components of net deferred tax liabilities are as follows (in thousands): As of December 31, 2017 2016 In-process $ 3,438 $ — Gross deferred tax liability $ 3,438 $ —
Reconciliation of Provision for Income Taxes and Provision Computed by Applying the Federal Statutory Rate to Net Loss Before Income Taxes	The provision for income taxes differs from the provision computed by applying the federal statutory rate to net loss before income taxes as follows: As of December 31, 2017 2016 U.S. federal statutory income tax rate (34.0 )% (34.0 )% State and local taxes, net of federal benefit 0.4 % — % Foreign rate differential 34.4 % 25.5 % Permanent differences 1.1 % 0.1 % Tax rate change and true-up 0.3 % — % Other 0.2 % — % Valuation allowance 0.1 % 10.4 % Tax credits (1.4 )% (2.0 )% Effective income tax rate 1.1 % 0.0 %
Schedule of Changes to Company's Unrecognized Tax Benefits	The following table indicates the changes to the Company’s unrecognized tax benefits (in thousands): As of December 31, 2017 2016 Beginning of the Year - unrecognized tax benefits $ — $ — Increases/ (Decrease) - prior year tax positions 44 — Increases - current year tax positions 28 — End of the Year - unrecognized tax benefits $ 72 $ —

Organization and Description 36

Organization and Description of Business - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017$ / sharesshares	Dec. 29, 2017$ / sharesshares	Dec. 31, 2016$ / sharesshares
Organization And Description Of Business [Line Items]
Reverse stock split, shares	0.03
Reverse stock split, description	Immediately prior to the Merger, the Galena effected a 1-for-30 reverse stock split of the Company’s outstanding common stock.
Common stock shares outstanding | shares	5,766,891	5,766,891	1,268,489
Common stock, par value (USD per share)	$ 0.0001	$ 0.0001	$ 0.0001
Private SELLAS [Member]
Organization And Description Of Business [Line Items]
Common stock conversion ratio	43.9972
Percentage of fully diluted common stock		67.50%
Common stock, par value (USD per share)		$ 10
Pre-Merger Securityholders [Member]
Organization And Description Of Business [Line Items]
Percentage of fully diluted common stock		32.50%

Organization and Description 37

Organization and Description of Business - Summary of Adjustments to Additional Paid-in Capital (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning balance	$ (4,997)	$ (12,262)
Shares issued as partial consideration of MSK license fees		900
Shares issued pursuant to MSK license agreement		1,976
Shares issued in cancellation of Clarendon license agreement		502
Shares issued upon conversion of 2016 convertible note	1,294	15,411
Shares issued in cancellation of long-term debt		5,803
Stock-based compensation	3,169	354
Ending balance	2,070	(4,997)
Additional Paid-in Capital
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning balance	25,434	488
Shares issued as partial consideration of MSK license fees		900
Shares issued pursuant to MSK license agreement		1,976
Shares issued in cancellation of Clarendon license agreement		502
Shares issued upon conversion of 2016 convertible note	1,294	15,411
Shares issued in cancellation of long-term debt		5,803
Stock-based compensation	3,169	354
Ending balance	56,254	25,434
Additional Paid-in Capital | Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning balance	25,146	288
Shares issued as partial consideration of MSK license fees		897
Shares issued pursuant to MSK license agreement		1,967
Shares issued in cancellation of Clarendon license agreement		500
Shares issued upon conversion of 2016 convertible note		15,357
Shares issued in cancellation of long-term debt		5,783
Stock-based compensation		354
Ending balance		25,146
Additional Paid-in Capital | Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Beginning balance	$ 288	200
Shares issued as partial consideration of MSK license fees		3
Shares issued pursuant to MSK license agreement		9
Shares issued in cancellation of Clarendon license agreement		2
Shares issued upon conversion of 2016 convertible note		54
Shares issued in cancellation of long-term debt		20
Ending balance		$ 288

Liquidity - Additional Informat

Liquidity - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 07, 2018	Jan. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Apr. 06, 2018	Dec. 31, 2016	Dec. 31, 2015
Liquidity [Line Items]
Redemption of debt through cash payment				$ 473
Outstanding principal balance				10,200
Cash and cash equivalents				2,319		$ 5,962	$ 1,397
Restricted cash				10,431		$ 85
Outstanding accounts payable and accrued expenses				14,900
Outstanding indebtedness				$ 10,988
Subsequent Event [Member]
Liquidity [Line Items]
Shares of common stock issued to satisfy the redemption of notes		623,749
Debenture [Member] | Subsequent Event [Member]
Liquidity [Line Items]
Redemption of debt through issuance of common stock			$ 2,600
Shares of common stock issued to satisfy the redemption of notes			635,894
Redemption of debt through cash payment			$ 600
Decrease in restricted cash and cash equivalent		$ 3,200	$ 3,200
Outstanding principal balance					$ 7,000
Series A- Convertible Preferred Stock [Member] | Subsequent Event [Member]
Liquidity [Line Items]
Aggregate gross proceeds from private placement	$ 10,700
First Tranche (Expected to Occur on or about March 2018) [Member] | Series A- Convertible Preferred Stock [Member] | Subsequent Event [Member]
Liquidity [Line Items]
Aggregate gross proceeds from private placement	6,000
Second Tranche (Expected to Occur Early in the Second Quarter) [Member] | Series A- Convertible Preferred Stock [Member] | Subsequent Event [Member]
Liquidity [Line Items]
Aggregate gross proceeds from private placement	$ 4,700

Basis of Presentation and Sum39

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Significant Accounting Policies [Line Items]
Exit costs severance benefits		$ 1,883
Corporate tax rate		34.00%	34.00%
Income tax expense		$ 253	$ 1
Scenario, Forecast [Member]
Significant Accounting Policies [Line Items]
Corporate tax rate	21.00%

Basis of Presentation and Sum40

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Potentially Dilutive Securities Outstanding Excluded from Computation of Diluted Weighted Average Shares Outstanding (Detail) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	986	122
Common stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	963
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	10	55
Unvested restricted stock awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	13	67

Business Combination - Addition

Business Combination - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 29, 2017	Dec. 31, 2017
Business Acquisition [Line Items]
Ownership percentage by parent	67.50%
Ownership percentage by non-controlling owners	32.50%
Transaction costs		$ 8,700
Shares issued to Equilibria for incentive fee payment in connection with the acquisition		941
Severance costs		1,883
Impairment charges		5,200
General and administrative expense [Member]
Business Acquisition [Line Items]
Transaction costs associated with the Merger		5,700
Galena Biopharma, Inc
Business Acquisition [Line Items]
Merger completion date	Dec. 29, 2017
Transaction costs		5,700
Success fee and other transaction costs		$ 4,800
Equilibria Collaboration Agreement
Business Acquisition [Line Items]
Shares issued to Equilibria for incentive fee payment in connection with the acquisition, shares	119,672	119,672
Shares issued to Equilibria for incentive fee payment in connection with the acquisition		$ 900

Business Combination - Summary

Business Combination - Summary of Purchase Price (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Business Combination, Consideration Transferred [Abstract]
Fair value of the Company's pre-Merger shares outstanding	$ 12,487
Estimated fair value of the Company's per-Merger stock options outstanding	32
Total purchase price	$ 12,519

Business Combination - Total Pu

Business Combination - Total Purchase Price Allocation (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 29, 2017
Assets acquired:
Goodwill	$ 1,914
Galena Biopharma, Inc
Assets acquired:
Cash		$ 1,812
Restricted cash		10,346
Prepaid expenses and other assets		3,103
Intangible assets		17,600
Goodwill		1,914
Total assets acquired		34,775
Liabilities assumed:
Accounts payable and accrued expenses		5,692
Litigation settlement		1,300
Long-term debt		10,988
Contingent purchase price consideration of Apthera, Inc.		1,294
Warrant liability		1,309
Deferred tax liability		1,673
Total liabilities assumed		22,256
Net assets acquired		$ 12,519

Business Combination - Pro form

Business Combination - Pro forma Consolidated Financial Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Business Combination Increase Decrease To Reflect Liabilities Acquired At Fair Value [Abstract]
Net revenues (in thousands)	$ 0	$ 0
Net loss (in thousands)	$ 24,089	$ 28,389
Basic and diluted net loss per share	$ 5.15	$ 8.61

Goodwill and Intangible Asset45

Goodwill and Intangible Assets - Summary of Changes in Carrying Amount of Goodwill (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill as a result of the Merger	$ 1,914
Balance as of December 31, 2017	$ 1,914

Goodwill and Intangible Asset46

Goodwill and Intangible Assets - Additional Information (Detail) - Galena Biopharma, Inc $ in Millions	Dec. 29, 2017USD ($)
Goodwill And Intangible Assets [Line Items]
Allocation of purchase price to acquired IPR&D	$ 17.6
GALE-401 [Member]
Goodwill And Intangible Assets [Line Items]
Allocation of purchase price to acquired IPR&D	9.1
NeuVax [Member]
Goodwill And Intangible Assets [Line Items]
Allocation of purchase price to acquired IPR&D	5.7
GALE-301 [Member]
Goodwill And Intangible Assets [Line Items]
Allocation of purchase price to acquired IPR&D	$ 2.8

Collaboration and License Agr47

Collaboration and License Agreements - Additional Information (Detail) € in Millions

Sep. 05, 2017USD ($)Tranche

May 25, 2017USD ($)shares

Feb. 24, 2017USD ($)

Sep. 30, 2016USD ($)shares

Aug. 10, 2016USD ($)shares

Aug. 09, 2016

Jun. 15, 2016

Jan. 18, 2016EUR (€)

Oct. 30, 2015shares

Oct. 29, 2015

Jul. 14, 2015USD ($)

Nov. 14, 2014

Sep. 04, 2014USD ($)shares

Dec. 31, 2017USD ($)

Dec. 31, 2016USD ($)Installment

Dec. 31, 2015USD ($)

Dec. 31, 2014USD ($)

Oct. 31, 2017USD ($)

Oct. 11, 2017shares

Sep. 11, 2006USD ($)

License And Collaboration Agreements [Line Items]

Research and development expense

$ 6,067,000

$ 11,395,000

The University of Texas M. D. Anderson Cancer Center and The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. License Agreement

License And Collaboration Agreements [Line Items]

Annual maintenance fee

$ 200,000

BioVascular Amendment

License And Collaboration Agreements [Line Items]

Royalty rate to be eliminated

3.00%

Royalty rate

4.00%

Previous annual net sales for royalty rate

$ 50,000,000

Annual net sales for royalty rate

100,000,000

Milestone payments receivable

$ 400,000

Number of tranches | Tranche

2

Sublicense fee payable percentage if executed prior to first patient enrolled in Phase 3 clinical trial

25.00%

Sublicense fee payable percentage if executed after first patient enrolled in Phase 3 clinical trial

17.50%

Proceeds from milestone

$ 100,000

BioVascular Amendment | Payable on or Before October 31, 2017 [Member]

License And Collaboration Agreements [Line Items]

Milestone payments receivable

$ 200,000

BioVascular Amendment | Payable 30 days after Merger but no later than December 31, 2017 [Member]

License And Collaboration Agreements [Line Items]

Milestone payments receivable

200,000

Clarendon License Agreement [Member]

License And Collaboration Agreements [Line Items]

License agreement termination date

Sep. 30, 2016

Liabilities under termination agreements agreed to pay in cash

$ 300,000

Shares issuable for consideration for license termination agreement | shares

7,700

Additional expense incurred to reflect fair value of shares issued

$ 200,000

Maximum | Advaxis Collaboration Agreement [Member]

License And Collaboration Agreements [Line Items]

Non refundable milestone payments

$ 108,000,000

Non refundable sales milestone payments

$ 250,000,000

MSK

License And Collaboration Agreements [Line Items]

License agreement effective date

Sep. 4, 2014

Shares issue | shares

8,799

Upfront license fees

$ 1,300,000

Minimum royalty payments

100,000

100,000

$ 100,000

Research funding costs

200,000

200,000

$ 200,000

Milestone payment

700,000

300,000

License agreement expiration term

10 years

License agreement outstanding amount payable

$ 1,000,000

600,000

Milestone payments due upon commencement

$ 300,000

MSK | MSK A&R License Agreement

License And Collaboration Agreements [Line Items]

Shares issue | shares

15,399

Milestone payment

$ 200,000

Milestone payments due upon commencement

$ 400,000

MSK | License Agreement

License And Collaboration Agreements [Line Items]

Shares issue | shares

13,199

Percentage of fully diluted share capital

1.50%

MSK | License Agreement | Chief Executive Officer Co Founder [Member]

License And Collaboration Agreements [Line Items]

Shares issue | shares

6,599

MSK | License Agreement | Vice Chairman

License And Collaboration Agreements [Line Items]

Shares issue | shares

6,599

MSK | License Agreement | Co-Founder

License And Collaboration Agreements [Line Items]

Shares issue | shares

6,599

MSK | First MSK Amendment

License And Collaboration Agreements [Line Items]

Shares issue | shares

10,867

Percentage of fully diluted share capital

1.00%

License agreement amendment date

Oct. 30, 2015

License agreement amendment extended date for financing

Dec. 31, 2016

Aug. 1, 2015

MSK | Second MSK Amendment

License And Collaboration Agreements [Line Items]

License agreement amendment date

Aug. 10, 2016

License agreement amendment extended date for financing

Jun. 30, 2017

Dec. 31, 2016

License agreement outstanding amount payable

$ 900,000

Issuance of shares upon conversion of debt in connection with licensing agreement | shares

13,815

Additional shares issued in connection with licensing agreement | shares

30,314

Research and development expense

$ 2,000,000

Milestone payments

$ 700,000

Number of installments to make payments | Installment

2

Maximum number of days to make payments

60 days

MSK | Second MSK A&R License Agreement

License And Collaboration Agreements [Line Items]

Shares issue | shares

74,795

Additional shares issued in connection with licensing agreement | shares

7,700

MSK | Maximum

License And Collaboration Agreements [Line Items]

Milestone payment

$ 17,400,000

Trojantec | Trojantec License Agreement [Member]

License And Collaboration Agreements [Line Items]

License fees

$ 300,000

License agreement date

Nov. 14, 2014

License agreement termination date

Jun. 15, 2016

Termination fees paid in cash

$ 100,000

Trojantec | First Trojantec Amendment [Member]

License And Collaboration Agreements [Line Items]

License agreement date

Jul. 14, 2015

Trojantec | Maximum | First Trojantec Amendment [Member]

License And Collaboration Agreements [Line Items]

Project management fees

$ 400,000

Clarendon Trading EInvestimentos LDA [Member] | Clarendon License Agreement [Member]

License And Collaboration Agreements [Line Items]

License fees | €

€ 0.5

License agreement date

Jan. 18, 2016

Fair Value Measurements - Conti

Fair Value Measurements - Contingent Purchase Price Consideration, Convertible Debt, Measured at Estimated Fair Value on Recurring Basis (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Assets:
Cash equivalents	$ 1,662
Restricted cash equivalents	10,245
Total assets measured and recorded at fair value	11,907
Liabilities:
Warrants potentially settleable in cash	1,309
Contingent consideration	1,294
Total liabilities measured and recorded at fair value	2,603
Fair Value, Measurements, Recurring | Quoted Prices In Active Markets (Level 1)
Assets:
Cash equivalents	1,662
Restricted cash equivalents	10,245
Total assets measured and recorded at fair value	11,907
Fair Value, Measurements, Recurring | Unobservable Inputs (Level 3)
Liabilities:
Warrants potentially settleable in cash	1,309
Contingent consideration	1,294
Total liabilities measured and recorded at fair value	$ 2,603

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value	$ 7,368
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Future contingent payments upon achievement of certain development and commercial milestones		$ 32,000
2015 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value	7,300
Carrying value	$ 7,400

Accrued Expenses and Other Cu50

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Professional fees	$ 1,744	$ 1,077
Value added tax	426
Rebates and returns	223
Compensation and related benefits	566	249
Clinical trial costs	51	2,496
Other	191	227
Accrued expenses and other current liabilities	$ 3,201	$ 4,049

Debt - Summary of Debt and Conv

Debt - Summary of Debt and Convertible Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Current portion of Senior Secured Debenture	$ 8,377
Non-current portion of Senior Secured Debenture	2,611
Total long-term debt	10,988
Total convertible debt		$ 7,368
Senior Secured Debentures
Debt Instrument [Line Items]
Current portion of Senior Secured Debenture	8,377
Non-current portion of Senior Secured Debenture	$ 2,611
2015 Shareholder Notes
Debt Instrument [Line Items]
Total convertible debt		1,709
2015 Sely Note
Debt Instrument [Line Items]
Total convertible debt		$ 5,659

Debt - Additional Information -

Debt - Additional Information - Senior Secured Debenture (Detail) - USD ($) $ / shares in Units, $ in Millions	May 10, 2016	Jan. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Apr. 06, 2018	Jan. 01, 2018
Debt Instrument [Line Items]
Debt instrument prepay lesser accrued and unpaid interest				$ 18.5
Outstanding principal balance				10.2
Senior secured debenture additional interest amount				$ 0.8
Subsequent Event [Member]
Debt Instrument [Line Items]
Number of shares available from warrants						501,000
Principal amount redeemed		$ 2.6
Shares issued to satisfy debt redemption		623,749
Cash paid to satisfy debt redemption		$ 0.6
Debenture [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Outstanding principal balance					$ 7
Shares issued to satisfy debt redemption			635,894
Decrease in restricted cash and cash equivalent		$ 3.2	$ 3.2
Secured Debt
Debt Instrument [Line Items]
Fixed coupon rate				9.00%
Interest under the Debenture				$ 0.8
Minimum price condition (per share)				$ 10.50
Secured Debt | Common Stock | Minimum
Debt Instrument [Line Items]
Cash in excess of debenture				$ 10
Secured Debt | Securities Purchase Agreement
Debt Instrument [Line Items]
Fixed coupon rate	6.375%
Principal amount of debt	$ 25.5
Number of shares available from warrants	3,333
Proceeds from issuance of debt and warrants	$ 23.4
Percentage of VWAPs				92.50%
Debt instrument, covenant, compensating cash balance				$ 18.5
Secured Debt | First Waiver
Debt Instrument [Line Items]
Debt repayments description				The Company does not have the right to prepay.
Secured Debt | Amendment Agreement
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage				80.00%
Percentage of VWAPs				80.00%
Number of days average for exercise price				20 days
Percentage of prior day VMAP				115.00%
Debt instrument, covenant, compensating cash balance				$ 10.2

Debt - Additional Information53

Debt - Additional Information - Convertible Debt (Detail) $ / shares in Units, $ in Thousands	Dec. 29, 2017shares	Jun. 21, 2017USD ($)	Jun. 13, 2017USD ($)$ / sharesshares	Nov. 01, 2016USD ($)shares	May 07, 2015USD ($)	Apr. 02, 2015USD ($)Holder	Aug. 31, 2017shares	Jun. 30, 2016USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Issued convertible term note to related party										$ 15,000
2015 Shareholder Notes
Debt Instrument [Line Items]
Aggregate principal amount						$ 1,500
Number of significant shareholders | Holder						2,000,000
Convertible notes bears interest rate						8.00%
Convertible debt, maturity date									Apr. 2, 2017
Conversion of debt, shares | shares	632,326
Warrants issued in full satisfaction of note | shares	316,163
Gain (loss) on extinguishment of debt									$ (700)
2015 Shareholder Notes | EQC Biotech Sely I Fund [Member]
Debt Instrument [Line Items]
Issued convertible term note to related party					$ 5,000
Shares issued upon conversion of debt in connection with acquisition of Galena Biopharma, Inc., shares | shares							632,328
Conversion of warrants term							5 years
Warrants issued | shares							316,163
Warrant exercise price as percent of debt conversion							105.00%
Debt instrument, convertible, term of notes							30 days
Bridge Financing
Debt Instrument [Line Items]
Capital increase approved by BOD			$ 7,300
Shares issued | shares			1,865,261
Share issue price per share | $ / shares			$ 3.91
Bridge Financing | 2015 Shareholder Notes
Debt Instrument [Line Items]
Shares subscribed by certain stockholders			$ 1,300
Subscribed by certain stockholders | shares			330,551
Principal amount paid		$ 300	$ 1,200
Cumulative accrued interest paid		$ 200	$ 100
2016 Notes
Debt Instrument [Line Items]
Aggregate principal amount								$ 15,000
Convertible notes bears interest rate								8.00%
Conversion of debt, shares | shares				236,705
Convertible note, conversion description									The 2016 Note was issued at par and had an interest rate of 8%. The 2016 Note was issued with similar terms to the 2015 Notes (excluding the warrant coverage) whereby the 2016 Note is mandatorily convertible into equity upon the earlier to occur: a) the closing of a qualified IPO, b) a change in the Company’s domicile from Switzerland to Bermuda or c) the six-month anniversary of the note.
Convertible note, accrued interest				$ 400
Debt conversion, converted instrument, gain (loss) recognized				$ 0

Debt - Additional Information54

Debt - Additional Information - Long-term Debt (Detail)	Nov. 01, 2016EUR (€)shares	Nov. 01, 2016USD ($)shares	Jun. 02, 2016USD ($)	May 12, 2016USD ($)	Apr. 12, 2016USD ($)	Apr. 06, 2016USD ($)	Mar. 02, 2015USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2015EUR (€)	Nov. 25, 2013EUR (€)
Debt Instrument [Line Items]
Borrowings | $								$ 10,988,000
Issuance of common stock | $								$ 6,007,000
Starcove Loans [Member]
Debt Instrument [Line Items]
Extinguishment of debt amount | $		$ 4,400,000
Issuance of common stock | $		$ 67,140
Founder Loans [Member]
Debt Instrument [Line Items]
Loan agreement period									3 years
Loan interest rate									2.50%
Modified terms on loan percentage maximum									10.00%
Debt conversion, converted instrument, gain (loss) recognized	€ 0
Third Party [Member] | 2015 Loan Agreement [Member]
Debt Instrument [Line Items]
Borrowings | $							$ 2,500,000
Loan agreement period							24 months
Loan interest rate							8.00%
Shareholders [Member] | 2013 Loan Agreement [Member]
Debt Instrument [Line Items]
Borrowings										€ 1,800,000
Loan interest rate										5.00%
Debt instrument description								The principal amount of the 2013 Loan Agreement, together with accrued interest, was re-assigned on a 50:50 basis to the Company’s co-founders, Drs. Angelos M. Stergiou (M.D., Sc.D. h.c.) and Miltiadis Sougioultzoglou (M.D.).
Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit | $			$ 300,000	$ 600,000	$ 600,000
Line of Credit [Member] | Starcove [Member] | Framework Loan Agreement [Member]
Debt Instrument [Line Items]
Loan agreement period						3 years
Line of credit | $						$ 1,500,000
Line of credit, interest rate						6.00%
Debt instrument frequency of payments								Single payment
Debt instrument maturity date						Apr. 6, 2019
Drs. Stergiou [Member]
Debt Instrument [Line Items]
Borrowings									€ 1,800,000
Drs. Stergiou [Member] | Founder Loans [Member]
Debt Instrument [Line Items]
Borrowings									700,000
Principal and accrued interest	€ 700,000
Conversion of debt, shares | shares	11,571	11,571
Sougioultzoglou [Member]
Debt Instrument [Line Items]
Borrowings									1,800,000
Sougioultzoglou [Member] | Founder Loans [Member]
Debt Instrument [Line Items]
Borrowings									600,000
Principal and accrued interest	€ 600,000
Conversion of debt, shares | shares	10,383	10,383
Drs. Stergiou and Sougioultzoglou [Member]
Debt Instrument [Line Items]
Borrowings accrued interest amount									100,000
Loans payable due									100,000
Loans receivables									€ 700,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information - Legal Proceedings (Detail) - USD ($)	Apr. 09, 2018	Nov. 07, 2017	Dec. 31, 2017	Dec. 31, 2016
Loss Contingencies [Line Items]
Issuance of Common Stock for Litigation Settlement			$ 1,250,000
Litigation settlement received			1,300,000
Paid by the company or their insurance carriers			50,000
Rental expense			200,000	$ 200,000
Qui Tam [Member]
Loss Contingencies [Line Items]
Payments for legal settlements		$ 300,000	100,000
Issuance of Common Stock for Litigation Settlement			200,000
JGB (Cayman) Newton, Ltd [Member] | Subsequent Event [Member]
Loss Contingencies [Line Items]
Issuance of common stock shares for litigation settlement	2,483,500
Settled Litigation [Member] | US Attorneys Office For The District Of New Jersey And Department Of Justice [Member]
Loss Contingencies [Line Items]
Total settlements			$ 7,600,000

Commitments and Contingencies56

Commitments and Contingencies - Schedule of Future Minimum Rental Commitments for Operating Leases (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,018	$ 223
2,019	76
Total	$ 299

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Jun. 13, 2017
Dr. Angelos Stergiou
Class of Stock [Line Items]
Cancellation of management fee	$ 100,000
Issuance of shares in cancellation of net compensation	28,246
MSK
Class of Stock [Line Items]
Issuance of common stock, shares	38,321
Milestone payment canceled	$ 200,000
Equilibria Collaboration Agreement
Class of Stock [Line Items]
Issuance of common stock, shares	30,094
Cancellation of management fee	$ 100,000
Bridge Financing
Class of Stock [Line Items]
Shares issued		1,865,261
Share issue price per share		$ 3.91

Stockholders' Equity - Common S

Stockholders' Equity - Common Stock are Reserved for Future Issuance (Detail) shares in Thousands	Dec. 31, 2017shares
Total reserved for future issuance	1,619
Common stock warrants
Total reserved for future issuance	963
Stock options outstanding
Total reserved for future issuance	10
Restricted stock units
Total reserved for future issuance	13
Stock options
Total reserved for future issuance	575
Employee Stock Purchase Plan
Total reserved for future issuance	58

Warrants - Schedule of Warrant

Warrants - Schedule of Warrant Activity (Detail) shares in Thousands	12 Months Ended
	Dec. 31, 2017shares
Class of Warrant or Right, Outstanding [Roll Forward]
Warrants outstanding , Beginning balance	0
Granted	316
Assumed through Merger	647
Class of Warrant or Right, Expired	0
Warrants outstanding, Ending balance	963
2017 Equilibria
Class of Warrant or Right, Outstanding [Roll Forward]
Warrants outstanding , Beginning balance	0
Granted	316
Assumed through Merger	0
Class of Warrant or Right, Expired	0
Warrants outstanding, Ending balance	316
Expiration	2022-12
Galena February 2017
Class of Warrant or Right, Outstanding [Roll Forward]
Warrants outstanding , Beginning balance	0
Granted	0
Assumed through Merger	567
Class of Warrant or Right, Expired	0
Warrants outstanding, Ending balance	567
Expiration	2022-02
Galena other
Class of Warrant or Right, Outstanding [Roll Forward]
Warrants outstanding , Beginning balance	0
Granted	0
Assumed through Merger	80
Class of Warrant or Right, Expired	0
Warrants outstanding, Ending balance	80
Expiration	Various to 2022

Warrants - Additional Informati

Warrants - Additional Information (Detail)	Jan. 01, 2018shares
Subsequent Event [Member]
Class of Warrant or Right [Line Items]
Warrants issued	501,000

Warrants - Fair Value of Warran

Warrants - Fair Value of Warrants is Estimated Using Black-Scholes Option Pricing Model (Detail) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Class of Warrant or Right [Line Items]
Warrants outstanding	963	0
Galena February 2017
Class of Warrant or Right [Line Items]
Warrants outstanding	567	0
Strike price (per share)	$ 33
Expected term (years)	4 years 1 month 13 days
Volatility%	79.29%
Risk-free rate %	2.09%
Other Galena Warrant Issues Accounted for as Liabilities [Member]
Class of Warrant or Right [Line Items]
Warrants outstanding	76
Strike price (per share)	$ 888.22
Expected term (years)	2 years 8 months 26 days
Volatility%	72.46%
Risk-free rate %	2.00%

Warrants - Changes in Fair Valu

Warrants - Changes in Fair Value of Warrant Liability (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Class of Warrant or Right, Fair Value [Roll Forward]
Fair Value of Warrants Granted	$ 0
Fair Value of Warrants Acquired	1,309
Change in fair value of warrants	0
Warrant liability, Ending balance	1,309
Galena February 2017
Class of Warrant or Right, Fair Value [Roll Forward]
Fair Value of Warrants Granted	0
Fair Value of Warrants Acquired	1,305
Change in fair value of warrants	0
Warrant liability, Ending balance	1,305
Galena other
Class of Warrant or Right, Fair Value [Roll Forward]
Fair Value of Warrants Granted	0
Fair Value of Warrants Acquired	4
Change in fair value of warrants	0
Warrant liability, Ending balance	$ 4

Warrants - Warrants Classified

Warrants - Warrants Classified as Equity (Detail) - 2017 Equilibria	Dec. 29, 2017$ / sharesshares
Class of Warrant or Right [Line Items]
Warrants issued | shares	316,163
Exercise price (in dollars per share)	$ 7.42
Warrant term	5 years
Fair value of warrants granted (in dollars per share)	$ 5.60
Fair value assumptions, expected volatility rate	90.10%
Fair value assumptions, expected term (in years)	5 years
Fair value assumptions, risk free interest rate	2.20%
Fair value assumptions, expected dividend rate	0.00%

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail)	Nov. 01, 2016shares	Dec. 31, 2017USD ($)Option$ / sharesshares	Dec. 31, 2016USD ($)$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted | Option		0
Weighted-average grant at fair value | $ / shares			$ 38.03
Aggregate intrinsic values outstanding and exercisable stock option Calculated based on the closing price of the Company's common stock as reported on the NASDAQ Capital Market | $ / shares		$ 7.86
2017 Equity Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for issuance		575,000
Share based compensation arrangement by share based payment award options assumed in merger		10,171
Option excisable period		1 year
Common stock options granted		0
Options expire from date of grant		10 years
Percentage increase in number of shares available for future issuance under stock based awards		4.00%
2016 Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for issuance	189,627
Options expire from date of grant	10 years
Vesting periods of options granted	3 years
RSUs with Time-Based and Performance-Based Conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Continued service measurement period		3 years
Compensation expense | $		$ 0	$ 0
RSUs with Time-Based and Performance-Based Conditions | January 1, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting date		Jan. 1, 2018
RSUs with Time-Based and Performance-Based Conditions | January 1, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting date		Jan. 1, 2019
RSUs with Time-Based and Performance-Based Conditions | January 1, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting date		Jan. 1, 2020
RSUs with Time-Based and Performance-Based Conditions | February 27, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting date		Feb. 27, 2018
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for issuance		57,000
Options expire from date of grant		10 years
Percentage increase in number of shares available for future issuance under stock based awards		1.00%
Share based compensation arrangement by share based payment award percentage earning of participants		15.00%
Issuance of common stock in connection with employee stock purchase plan, shares		102,279

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Allocated Stock-based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share based compensation expense	$ 3,169	$ 354
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share based compensation expense	729	23
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share based compensation expense	$ 2,440	$ 331

Stock-Based Compensation - Sc66

Stock-Based Compensation - Schedule of Grant Date Fair Values of Option Issued to Employees and Non-Employees (Detail) - Employee and Non-Employee Stock Options	12 Months Ended
	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest rate	1.82%
Volatility rate	85.00%
Expected lives (years)	5 years 1 month 17 days
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest rate	2.32%
Volatility rate	94.00%
Expected lives (years)	10 years

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of options, Beginning balance	55
Assumed in connection with the Merger with Galena	10	55
Number of options, Canceled	(55)
Number of options, Ending balance	10	55
Number of options, exercisable	10
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Weighted average exercise price, Beginning balance	$ 52.94
Assumed in connection with the Merger with Galena	1,240.55	$ 52.94
Weighted average exercise price, Canceled	52.94
Weighted average exercise price, Ending balance	1,240.55	$ 52.94
Weighed average exercise price, exercisable	$ 1,240.55
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Aggregate intrinsic value, Beginning balance	$ 0	$ 0
Assumed in connection with the Merger with Galena	$ 0
Aggregate intrinsic value, Granted		$ 0
Aggregate intrinsic value,Canceled	$ 0
Aggregate intrinsic value, Ending balance	0	$ 0
Aggregate intrinsic Value, exercisable	$ 0

Stock-Based Compensation - RSU

Stock-Based Compensation - RSU Activity for RSUs with Only Time-Based Condition (Detail) - RSUs with Time Based Conditions - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of non-vested RSUs, Beginning Balance	46
Number of non-vested RSUs, Granted	58	46
Number of non-vested RSUs, Vested	(46)
Number of non-vested RSUs, Canceled	(58)
Number of non-vested RSUs, Ending Balance		46
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted average grant-date fair value, Beginning Balance	$ 52.94
Weighted average grant-date fair value, Granted	3.91	$ 52.94
Weighted average grant-date fair value, Vested	52.94
Weighted average grant-date fair value, Canceled	$ 3.91
Weighted average grant-date fair value, Ending Balance		$ 52.94

Stock-Based Compensation - RS69

Stock-Based Compensation - RSU Activity for RSUs with Both Time-Based and Performance-Based Condition (Detail) - RSUs with Time-Based and Performance-Based Conditions - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of non-vested RSUs, Beginning Balance	21
Number of non-vested RSUs, Vested	0
Number of non-vested RSUs, Granted		21
Number of non-vested RSUs, Canceled	(8)
Number of non-vested RSUs, Ending Balance	13	21
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted average grant-date fair value, Beginning Balance	$ 52.94
Weighted average grant-date fair value, Canceled	52.94
Weighted average grant-date fair value, Granted		$ 52.94
Weighted average grant-date fair value, Ending Balance	$ 52.94	$ 52.94

Income Taxes - Schedule of Loss

Income Taxes - Schedule of Loss Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
U.S.	$ 265	$ 108
Non - U.S.	(23,766)	(17,788)
Loss before income taxes	$ (23,501)	$ (17,680)

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Current
Federal	$ 76
State	138	$ 42
Foreign	0	0
Total current	214	42
Deferred expense
Federal	0	0
State	39	(41)
Foreign	0	0
Total deferred	39	(41)
Total income tax expense	$ 253	$ 1

Income Taxes - Components of Ne

Income Taxes - Components of Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets
Net operating loss carryforwards	$ 1,028	$ 3,145
Tax credit carryforwards	345	295
Stock based compensation	2,550	28
Licensing deduction deferral	2,105
Other	395	81
Gross deferred tax assets	6,423	3,549
Valuation allowance	(4,658)	(3,508)
Net deferred tax asset	$ 1,765	$ 41

Income Taxes - Components of 73

Income Taxes - Components of Net Deferred Tax Liabilities (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Income Tax Disclosure [Abstract]
In-process research and development not subject to future amortization for tax purposes	$ 3,438
Gross deferred tax liability	$ 3,438

Income Taxes - Schedule of Prov

Income Taxes - Schedule of Provision Computed by Applying Federal Statutory Rate (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
U.S. federal statutory income tax rate	(34.00%)	(34.00%)
State and local taxes, net of federal benefit	0.40%
Foreign rate differential	34.40%	25.50%
Permanent differences	1.10%	0.10%
Tax rate change and true-up	0.30%
Other	0.20%
Valuation allowance	0.10%	10.40%
Tax credits	(1.40%)	(2.00%)
Effective income tax rate	1.10%	0.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Tax Credit Carryforward [Line Items]
Federal operating loss carryforwards		$ 3,700,000
State operating loss carryforwards		$ 3,700,000
Operating loss carryforwards expire start year		2,027
Operating loss carryforwards expire end year		2,027
Period of ownership percentage change		3 years
Change in ownership percentage, minimum		50.00%
Maximum indefinite-lived deferred tax liability as percentage of net operating loss		80.00%
Deferred tax assets indefinite-lived NOL		$ 1,800,000
Increase in valuation allowance		1,200,000	$ 1,800,000
Impact on tax provision from unrecognized tax benefits		$ 28,000	$ 44,000
U.S. federal statutory income tax rate		34.00%	34.00%
Scenario, Forecast [Member]
Tax Credit Carryforward [Line Items]
U.S. federal statutory income tax rate	21.00%
Domestic Tax Authority [Member]
Tax Credit Carryforward [Line Items]
Research and development tax credit carryforwards		$ 400,000

Income Taxes - Schedule of Chan

Income Taxes - Schedule of Changes to Company's Unrecognized Tax Benefits (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Increases/ (Decrease) - prior year tax positions	$ 44
Increases - current year tax positions	28
End of the Year - unrecognized tax benefits	$ 72

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	Dec. 29, 2017	Jun. 30, 2016	Nov. 28, 2016	Dec. 31, 2017	Dec. 31, 2016
Number of options, Granted				10,000	55,000
Equilibria Collaboration Agreement
Effective period of agreement		3 years
Quarterly management fee		$ 100,000
Management fees incurred and paid in cash				$ 300,000	$ 200,000
Outstanding fee payable				$ 100,000	$ 0
Incentive fee percentage equal to post - money market value		2.00%
Incentive fee percentage equal to gross value paid by purchaser in cash		2.00%
Compensation payable	$ 100,000
Shares issued to Equilibria for incentive fee payment in connection with the acquisition, shares	119,672			119,672
General and administrative expense	$ 900,000
MSK License Agreement [Member]
Number of granted stock options			3,651
Contract termination date			Aug. 6, 2017
Cash payment for termination fees			$ 30,000
MSK License Agreement [Member] | Restricted Stock Units [Member]
Number of options, Granted			9,107
MSK License Agreement [Member] | Dr Angelos MStergiou [Member]
Percentage of ownership outstanding share capital				7.80%	24.00%
MSK License Agreement [Member] | MSK
Percentage of ownership outstanding share capital				3.70%	5.40%

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($)

Aug. 22, 2018

Apr. 30, 2018

Apr. 09, 2018

Apr. 03, 2018

Apr. 02, 2018

Mar. 09, 2018

Mar. 08, 2018

Mar. 07, 2018

Feb. 22, 2018

Feb. 19, 2018

Feb. 15, 2018

Feb. 14, 2018

Feb. 13, 2018

Feb. 09, 2018

Feb. 07, 2018

Feb. 06, 2018

Jan. 16, 2018

Jan. 31, 2018

Dec. 31, 2018

Jun. 30, 2018

Jan. 01, 2018

Dec. 31, 2017

Dec. 29, 2017

Dec. 31, 2016

Common Stock, Par or Stated Value Per Share

$ 0.0001

$ 0.0001

$ 0.0001

Common stock issued

5,766,891

1,268,489

Ownership percentage by Parent

32.50%

Convertible Preferred Stock, par value

$ 0.0001

$ 0.0001

Subsequent Event [Member]

Number of common stock shares issued for debt conversion

623,749

Number of securities called by warrants or rights

501,000

Subsequent Event [Member] | Series A- Convertible Preferred Stock [Member]

Preferred Units, Description

Series A Convertible Preferred: On March 8, 2018, the Company filed a Certificate of Designation of Preferences, Rights and Limitations of Series A 20% Convertible Preferred Stock (the “Certificate of Designation”) with the Secretary of State of the State of Delaware, which designated up to 17,500 shares of Series A Convertible Preferred.

Convertible Preferred Stock, par value

$ 1,000

Convertible Preferred stock stated value percentage

20.00%

Equity method investment, ownership percentage

9.99%

Beneficial ownership limitation,percentage

4.99%

Percentage of stock conversion limit

19.99%

Adjustment to common stock in connection with reverse/forward stock split

$ 3

Trading days

5 days

Subsequent Event [Member] | Minimum

Percentage of reduction in risk recurrence

34.90%

Subsequent Event [Member] | Maximum

Percentage of reduction in risk recurrence

39.50%

Subsequent Event [Member] | Maximum | Series A- Convertible Preferred Stock [Member]

Convertible Preferred Stock, Shares Issued upon Conversion

17,500

Subsequent Event [Member] | Scenario, Forecast [Member] | Series A- Convertible Preferred Stock [Member]

Convertible Preferred stock stated value percentage

20.00%

20.00%

Subsequent Event [Member] | JGB (Cayman) Newton, Ltd [Member]

Issuance of common stock shares for litigation settlement

2,483,500

Subsequent Event [Member] | CVI Agreement [Member]

Company had previously issued to CVI a warrant to purchase

99,333

Common Stock, Par or Stated Value Per Share

$ 0.0001

Denominator base for issuance of common stock

$ 232,440

Convertible promissory note principal amount

$ 232,440

Accrued interest on the outstanding principal amount

5.00%

Increase accrued interest on the outstanding principal

18.00%

Common stock conversion price

$ 7

Minimum percentage outstanding Common Stock to effect conversion

4.99%

Debt Instrument, Redemption Price, Percentage

70.00%

Number of common stock shares issued for debt conversion

33,356

Subsequent Event [Member] | Anson Agreement [Member]

Common stock issued

30,000

Shares of common stock in exchange

12,536

Subsequent Event [Member] | Sabby Agreement [Member]

Purchase of aggregate shares

83,333

Closing sale price of common stock

$ 195,000

Minimum percentage of daily trading volume of common stock

2.00%

Percentage of market price

100.00%

Subsequent Event [Member] | Hudson Bay Agreement [Member]

Convertible promissory note principal amount

$ 343,200

Accrued interest on the outstanding principal amount

5.00%

Increase accrued interest on the outstanding principal

18.00%

Common stock conversion price

$ 7

Minimum percentage outstanding Common Stock to effect conversion

9.99%

Debt Instrument, Redemption Price, Percentage

70.00%

Number of common stock shares issued for debt conversion

49,390

Purchase of aggregate shares

146,666

Subsequent Event [Member] | Alto Agreement [Member]

Convertible promissory note principal amount

$ 249,600

Accrued interest on the outstanding principal amount

5.00%

Increase accrued interest on the outstanding principal

18.00%

Minimum percentage outstanding Common Stock to effect conversion

9.99%

Debt Instrument, Redemption Price, Percentage

70.00%

Number of common stock shares issued for debt conversion

35,998

Shares of common stock in exchange

45,464

Purchase of aggregate shares

106,667

Closing sale price of common stock

$ 249,600

Subsequent Event [Member] | Lincoln Park Agreement [Member]

Shares of common stock in exchange

3,421

Purchase of aggregate shares

8,333

Subsequent Event [Member] | Empery Agreement [Member]

Company had previously issued to CVI a warrant to purchase

26,668

Common Stock, Par or Stated Value Per Share

$ 0.0001

Convertible promissory note principal amount

$ 64,403.12

Accrued interest on the outstanding principal amount

4.75%

Increase accrued interest on the outstanding principal

18.00%

Debt Instrument, Redemption Price, Percentage

70.00%

Subsequent Event [Member] | Purchase Agreement [Member]

Common Stock, Par or Stated Value Per Share

$ 0.0001

Number of securities called by warrants or rights

1,383,631

Convertible preferred stock and warrant purchase price

$ 10,700,000

Convertible Preferred Stock, Shares Issued upon Conversion

1,844,835

Preferred stock conversion price

$ 5.80

Subsequent Event [Member] | Purchase Agreement [Member] | Series A- Convertible Preferred Stock [Member]

Number of convertible preferred stock issued

10,700

Number of securities called by warrants or rights

1,383,631

Date by which stock holder approval required

May 7, 2018

Period of stock holder approval

60 days

Purchase price of common stock, percent

75.00%

Exercise Price of Warrants

$ 6.59

Date from which warrants exercisable

5 years

Subsequent Event [Member] | Voting Agreement [Member] | Minimum

Ownership percentage by Parent

10.00%

Percentage of Voting Interests Acquired

50.00%

Common stock percentage issued prior to purchase agreement

19.99%

Subsequent Event [Member] | Engagement Letter [Member]

Gross offering proceeds percentage

7.00%

Subsequent Event [Member] | Private Placement First Closing [Member] | Purchase Agreement [Member] | Series A- Convertible Preferred Stock [Member]

Number of convertible preferred stock issued

5,987

Convertible preferred stock and warrant purchase price

$ 5,987,000

Warrant issued

774,186

Subsequent Event [Member] | Private Placement Second Closing [Member] | Purchase Agreement [Member] | Series A- Convertible Preferred Stock [Member]

Number of convertible preferred stock issued

4,713

Convertible preferred stock and warrant purchase price

$ 4,713,000

Warrant issued

609,445

Subsequent Event [Member] | Qualified Public Offering [Member] | Purchase Agreement [Member] | Series A- Convertible Preferred Stock [Member]

Minimum proceed required under qualified offering

$ 20,000,000

Convertible Preferred Stock, conversion basis

On a $1.00 for $1.00 basis

Qualified offering description

Qualified Offering is defined in the purchase agreement and the Certificate of Designation (as defined below) as a public offering raising aggregate gross proceeds of no less than $20.0 million.