Celldex Therapeutics (CLDX) 10-Q 7 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 30, 2019
Document and Entity Information
Entity Registrant Name	Celldex Therapeutics, Inc.
Entity Central Index Key	0000744218
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		13,768,878
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current Assets:
Cash and Cash Equivalents	$ 31,533	$ 24,310
Marketable Securities	53,535	69,712
Accounts and Other Receivables	2,307	3,162
Prepaid and Other Current Assets	1,476	1,895
Total Current Assets	88,851	99,079
Property and Equipment, Net	5,462	6,111
Operating Lease Right-of-Use Assets, Net	4,445
Intangible Assets, Net	48,690	48,690
Other Assets	129	1,929
Total Assets	147,577	155,809
Current Liabilities:
Accounts Payable	1,105	1,069
Accrued Expenses	5,474	7,007
Current Portion of Operating Lease Liabilities	2,633
Current Portion of Other Long-Term Liabilities	2,777	4,526
Total Current Liabilities	11,989	12,602
Long-Term Portion of Operating Lease Liabilities	2,599
Other Long-Term Liabilities	20,296	19,147
Total Liabilities	34,884	31,749
Commitments and Contingent Liabilities
Stockholders' Equity:
Convertible Preferred Stock, $.01 Par Value; 3,000,000 Shares Authorized; No Shares Issued and Outstanding at March 31, 2019 and December 31, 2018
Common Stock, $.001 Par Value; 297,000,000 Shares Authorized; 12,844,711 and 11,957,635 Shares Issued and Outstanding at March 31, 2019 and December 31, 2018, Respectively	13	12
Additional Paid-In Capital	1,089,755	1,083,903
Accumulated Other Comprehensive Income	2,602	2,583
Accumulated Deficit	(979,677)	(962,438)
Total Stockholders' Equity	112,693	124,060
Total Liabilities and Stockholders' Equity	$ 147,577	$ 155,809

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
CONDENSED CONSOLIDATED BALANCE SHEETS
Convertible Preferred Stock, Par Value (in dollars per share)	$ 0.01	$ 0.01
Convertible Preferred Stock, Shares Authorized	3,000,000	3,000,000
Convertible Preferred Stock, Shares Issued	0	0
Convertible Preferred Stock, Shares Outstanding	0	0
Common Stock, Par Value (in dollars per share)	$ 0.001	$ 0.001
Common Stock, Shares Authorized	297,000,000	297,000,000
Common Stock, Shares Issued	12,844,711	11,957,635
Common Stock, Shares Outstanding	12,844,711	11,957,635

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
REVENUES:
Total Revenues	$ 1,425	$ 4,068
OPERATING EXPENSES:
Research and Development	11,151	21,875
General and Administrative	4,896	5,593
Goodwill Impairment		90,976
Intangible Asset Impairment		18,677
Other Asset Impairment	1,800
Loss/(Gain) on Fair Value Remeasurement of Contingent Consideration	1,519	(13,600)
Amortization of Acquired Intangible Assets	0	224
Total Operating Expenses	19,366	123,745
Operating Loss	(17,941)	(119,677)
Investment and Other Income, Net	702	780
Net Loss Before Income Tax Benefit	(17,239)	(118,897)
Income Tax Benefit		765
Net Loss	$ (17,239)	$ (118,132)
Basic and Diluted Net Loss Per Common Share	$ (1.40)	$ (12.61)
Shares Used in Calculating Basic and Diluted Net Loss Per Share	12,297	9,370
COMPREHENSIVE LOSS:
Net Loss	$ (17,239)	$ (118,132)
Other Comprehensive Income (Loss):
Unrealized Gain (Loss) on Marketable Securities	19	(5)
Comprehensive Loss	(17,220)	(118,137)
Product Development and Licensing Agreements
REVENUES:
Total Revenues	129	992
Contracts and Grants
REVENUES:
Total Revenues	$ 1,296	$ 3,076

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOW - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash Flows From Operating Activities:
Net Loss	$ (17,239)	$ (118,132)
Adjustments to Reconcile Net Loss to Net Cash Used in Operating Activities:
Depreciation and Amortization	1,352	1,028
Amortization of Intangible Assets	0	224
Amortization and Premium of Marketable Securities, Net	(345)	(155)
Loss on Sale or Disposal of Assets	25	10
Goodwill Impairment		90,976
Intangible Asset Impairment		18,677
Other Asset Impairment	1,800
Loss/(Gain) on Fair Value Remeasurement of Contingent Consideration	1,519	(13,600)
Non-Cash Income Tax Benefit		(765)
Stock-Based Compensation Expense	1,693	2,488
Changes in Operating Assets and Liabilities:
Accounts and Other Receivables	855	(1,635)
Prepaid and Other Current Assets	299	(144)
Accounts Payable and Accrued Expenses	(1,455)	(5,919)
Other Liabilities	(1,737)	(1,075)
Net Cash Used in Operating Activities	(13,233)	(28,022)
Cash Flows From Investing Activities:
Sales and Maturities of Marketable Securities	37,886	46,871
Purchases of Marketable Securities	(21,404)	(31,117)
Acquisition of Property and Equipment	(186)	(259)
Net Cash Provided by Investing Activities	16,296	15,495
Cash Flows From Financing Activities:
Net Proceeds from Stock Issuances	4,151	11,689
Proceeds from Issuance of Stock from Employee Benefit Plans	9	374
Net Cash Provided by Financing Activities	4,160	12,063
Net Increase/(Decrease) in Cash and Cash Equivalents	7,223	(464)
Cash and Cash Equivalents at Beginning of Period	24,310	40,288
Cash and Cash Equivalents at End of Period	31,533	39,824
Non-cash Investing Activities
Accrued construction in progress	$ 65	212
Non-cash Supplemental Disclosure
Shares issued to former Kolltan executive for settlement of severance		$ 38

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2019
Basis of Presentation
Basis of Presentation	(1) Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared by Celldex Therapeutics, Inc. (the “Company” or “Celldex”) in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and reflect the operations of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. These interim financial statements do not include all the information and footnotes required by U.S. GAAP for annual financial statements and should be read in conjunction with the audited financial statements for the year ended December 31, 2018, which are included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 7, 2019. In the opinion of management, the interim financial statements reflect all normal recurring adjustments necessary to fairly state the Company’s financial position and results of operations for the interim periods presented. The year-end condensed balance sheet data presented for comparative purposes was derived from audited financial statements but does not include all disclosures required by U.S. GAAP. The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for any future interim period or the fiscal year ending December 31, 2019. At March 31, 2019, the Company had cash, cash equivalents and marketable securities of $85.1 million. The Company has had recurring losses and incurred a loss of $17.2 million for the three months ended March 31, 2019. Net cash used in operations for the three months ended March 31, 2019 was $13.2 million. The Company believes that the cash, cash equivalents and marketable securities at May 7, 2019 will be sufficient to meet estimated working capital requirements and fund planned operations for at least the next twelve months from the date of issuance of these financial statements. The Board of Directors of the Company approved a one for fifteen reverse stock split of the Company’s outstanding common stock, which was effected on February 8, 2019. All share and per share amounts in the financial statements have been retroactively adjusted for all periods presented to give effect to the reverse stock split, including reclassifying an amount equal to the reduction in par value to additional paid-in capital. During the next twelve months and beyond, the Company will take further steps to raise additional capital to meet its liquidity needs. These capital raising activities may include, but may not be limited to, one or more of the following: the licensing of drug candidates with existing or new collaborative partners, possible business combinations, issuance of debt, or the issuance of common stock or other securities via private placements or public offerings. While the Company may seek capital through a number of means, there can be no assurance that additional financing will be available on acceptable terms, if at all, and the Company’s negotiating position in capital-raising efforts may worsen as existing resources are used. There is also no assurance that the Company will be able to enter into further collaborative relationships. Additional equity financings may be dilutive to the Company’s stockholders; debt financing, if available, may involve significant cash payment obligations and covenants that restrict the Company’s ability to operate as a business; and licensing or strategic collaborations may result in royalties or other terms which reduce the Company’s economic potential from products under development. The Company’s ability to continue funding its planned operations into and beyond twelve months from the issuance date is also dependent on the timing and manner of payment of future contingent milestones from the Kolltan acquisition, in the event that the Company achieves the drug candidate milestones related to those payments. The Company, at its option, may decide to pay those milestone payments in cash, shares of its common stock or a combination thereof. If the Company is unable to raise the funds necessary to meet its liquidity needs, it may have to delay or discontinue the development of one or more programs, discontinue or delay ongoing or anticipated clinical trials, license out programs earlier than expected, raise funds at a significant discount or on other unfavorable terms, if at all, or sell all or a part of the Company.

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2019
Significant Accounting Policies
Significant Accounting Policies	(2) Significant Accounting Policies The significant accounting policies used in preparation of these condensed consolidated financial statements on Form 10-Q for the three months ended March 31, 2019 are consistent with those discussed in Note 2 to the financial statements in our Annual Report on Form 10-K for the year ended December 31, 2018, except as it relates to the adoption of new accounting standards during the first three months of 2019 as discussed below. Newly Adopted Accounting Pronouncements On January 1, 2019, the Company adopted a new U.S. GAAP accounting standard which requires that all lessees recognize the assets and liabilities that arise from leases on the balance sheet and disclose qualitative and quantitative information about its leasing arrangements. The new standard was adopted using the modified retrospective transition method, which requires the Company to apply the standard as of the effective date and does not require restatement of prior periods. The Company elected to apply the package of practical expedients, which allowed the Company to not reassess: (i) whether expired or existing contracts contain leases; (ii) lease classification for any expired or existing leases; and (iii) initial direct costs for any existing leases. Adoption of this standard did not have a material impact on the Company's Consolidated Statement of Operations and Comprehensive Loss or Statement of Cash Flow, however, upon adoption, the Company recorded right-of-use assets of $3.8 million and lease liabilities of $4.7 million on its Consolidated Balance Sheet related to the Company's operating leases. The difference between the right-of-use assets and lease liabilities recorded upon adoption is due to certain adjustments required to the right-of-use assets for prepaid rent and accrued termination expenses. Refer to Note 5 “Leases” for the Company’s updated lease accounting policy and disclosures. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on the Company’s consolidated financial statements upon adoption. In June 2016, the FASB issued guidance on the Measurement of Credit Losses on Financial Instruments. The guidance requires that credit losses be reported using an expected losses model rather than the incurred losses model that is currently used, and establishes additional disclosures related to credit risks. For available-for-sale debt securities with unrealized losses, the standard now requires allowances to be recorded instead of reducing the amortized cost of the investment. This standard will be effective for the Company on January 1, 2020. We are currently evaluating the potential impact that this standard may have on the Company's consolidated financial statements and related disclosures. In August 2018, the FASB issued amendments that modify certain disclosure requirements for fair value measurements. The amendments become effective, including interim periods, beginning January 1, 2020. Early adoption, of all the amendments or only the provisions that eliminate or modify the requirements, is permitted. The adoption of this new guidance is not expected to have a material impact on the Company's consolidated financial statements and related disclosures. In November 2018, the FASB issued guidance to clarify the interaction between the accounting guidance for collaborative arrangements and revenue from contracts with customers. The amendments become effective, including interim periods, beginning January 1, 2020. Early adoption, including adoption in an interim period, is permitted. This guidance is required to be applied retrospectively as of the date of our adoption of the new revenue standard on January 1, 2018. We are currently evaluating the timing of our adoption and the expected impact this guidance could have on our consolidated financial statements and related disclosures.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2019
Fair Value Measurements
Fair Value Measurements	(3) Fair Value Measurements The following tables set forth the Company’s financial assets and liabilities subject to fair value measurements: As of March 31, 2019 Level 1 Level 2 Level 3 (In thousands) Assets: Money market funds and cash equivalents $ 21,432 — $ 21,432 — Marketable securities 53,535 — 53,535 — $ 74,967 — $ 74,967 — Liabilities: Kolltan acquisition contingent consideration $ 15,298 — — $ 15,298 $ 15,298 — — $ 15,298 As of December 31, 2018 Level 1 Level 2 Level 3 (In thousands) Assets: Money market funds and cash equivalents $ 15,755 — $ 15,755 — Marketable securities 69,712 — 69,712 — $ 85,467 — $ 85,467 — Liabilities: Kolltan acquisition contingent consideration $ 13,779 — — $ 13,779 $ 13,779 — — $ 13,779 The Company’s financial assets consist mainly of money market funds and cash equivalents and marketable securities and are classified as Level 2 within the valuation hierarchy. The Company values its marketable securities utilizing independent pricing services which normally derive security prices from recently reported trades for identical or similar securities, making adjustments based on significant observable transactions. At each balance sheet date, observable market inputs may include trade information, broker or dealer quotes, bids, offers or a combination of these data sources. The following table reflects the activity for the Company’s contingent consideration liabilities measured at fair value using Level 3 inputs for the three months ended March 31, 2019 (in thousands): Other Liabilities: Contingent Consideration Balance at December 31, 2018 $ 13,779 Fair value adjustments included in operating expenses 1,519 Balance at March 31, 2019 $ 15,298 The valuation technique used to measure fair value of the Company’s Level 3 liabilities, which consist of contingent consideration related to the acquisition of Kolltan in 2016, was primarily an income approach. The Company may be required to pay future consideration of up to $127.5 million that is contingent upon the achievement of specified development, regulatory approvals or sales-based milestone events. The significant unobservable inputs used in the fair value measurement of the contingent consideration are estimates including probability of success, discount rates and amount of time until the conditions of the milestone payments are met. During the three months ended March 31, 2019, the Company recorded a $1.5 million loss on fair value remeasurement of contingent consideration, primarily due to changes in discount rates and the passage of time. During the three months ended March 31, 2018, the Company recorded a $13.6 million gain on fair value remeasurement of contingent consideration, primarily due to updated assumptions for Glemba-related milestones due to the METRIC failure and discontinuation of the Glemba program. The Company did not have any transfers of assets or liabilities between the fair value measurement classifications during the three months ended March 31, 2019.

Marketable Securities

Marketable Securities	3 Months Ended
	Mar. 31, 2019
Marketable Securities
Marketable Securities	(4) Marketable Securities The following is a summary of marketable securities, classified as available-for-sale: Gross Unrealized Amortized Fair Cost Gains Losses Value (In thousands) March 31, 2019 U.S. government and municipal obligations (maturing in one year or less) $ 17,641 $ 3 $ — $ 17,644 Corporate debt securities (maturing in one year or less) 35,888 4 (1) 35,891 Total Marketable Securities $ 53,529 $ 7 $ (1) $ 53,535 December 31,2018 U.S. government and municipal obligations (maturing in one year or less) $ 27,355 $ — $ (4) $ 27,351 Corporate debt securities (maturing in one year or less) 42,370 — (9) 42,361 Total Marketable Securities $ 69,725 $ — $ (13) $ 69,712 The Company holds investment-grade marketable securities, and none were in a continuous unrealized loss position for more than twelve months as of March 31, 2019 and December 31, 2018. The unrealized losses are attributable to changes in interest rates and the Company does not believe any unrealized losses represent other-than-temporary impairments. Marketable securities include $0.1 million in accrued interest at March 31, 2019 and December 31, 2018.

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Leases
Leases	(5) Leases The Company has operating leases of office and laboratory space, which have remaining lease terms of one to six years and may include one or more options to renew or terminate early. The Company determines if an arrangement contains a lease at inception. Operating lease right-of-use assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. Certain adjustments to the right-of-use asset may be required for items such as prepaid or accrued lease payments, initial direct costs paid or incentives received. The Company’s leases do not contain an implicit rate, and therefore the Company uses an estimated incremental borrowing rate based on the information available at the lease commencement date in determining the present value of lease payments. Options to extend or terminate the lease are reflected in the calculation when it is reasonably certain that the option will be exercised. The Company has elected to account for lease and non-lease components as a single lease component, however non-lease components that are variable, such as common area maintenance and utilities, are generally paid separately from rent based on actual costs incurred and therefore are not included in the right-of-use asset and operating lease liability and are reflected as an expense in the period incurred. Leases with an initial term of 12 months or less are not recorded on the balance sheet. During the quarter ended March 31, 2019, the Company amended its Hampton, New Jersey lease to eliminate 16,200 square feet of space and extend the remaining 33,400 square feet of space for an additional five-year term with an early termination option after three years. The Company recorded an additional right-of-use asset and lease liability of $1.4 million for the initial 3 years related to the amendment. Operating lease expense and variable lease expense was $0.7 million and $0.4 million for the three months ended March 31, 2019, respectively. Operating cash flows used for operating leases during the three months ended March 31, 2019 was $0.9 million. As of March 31, 2019, the weighted-average remaining lease term was 2 years and the weighted-average discount rate was 11.3%. Future minimum lease payments under non-cancellable leases as of March 31, 2019 were as follows: Remainder of 2019 $ 2,277 2020 2,171 2021 508 2022 746 2023 311 Total lease payments 6,013 Less imputed interest (781) Present value of operating lease liabilities $ 5,232 Under the prior lease accounting guidance, operating lease obligations, including estimated variable lease obligations, as of December 31, 2018 were as follows: 2019 $ 4,648 2020 3,140 Thereafter — Total lease payments $ 7,788

Intangible Assets and Goodwill

Intangible Assets and Goodwill	3 Months Ended
	Mar. 31, 2019
Intangible Assets and Goodwill
Intangible Assets and Goodwill	(6) Intangible Assets and Goodwill Intangible Assets, Net As a result of the discontinuation of the Glemba program, the Company concluded that the finite-lived intangible asset related to its Amgen Fremont license rights to develop and commercialize Glemba was fully impaired and a non-cash impairment charge of $6.9 million was recorded in the first quarter of 2018. Amortization expense related to this finite-lived intangible asset was $0.0 million and $0.2 million for the three months ended March 31, 2019 and 2018, respectively. At March 31, 2019 and 2018, the Company recorded indefinite-lived intangible assets of $48.7 million. Indefinite-lived intangible assets consist of acquired in-process research and development (“IPR&D”) related to the development of CDX-3379, the anti-KIT program and the TAM program. CDX-3379 is in Phase 2 development. The anti-KIT and TAM programs are in preclinical development. As of March 31, 2019, none of the Company’s IPR&D assets had reached technological feasibility nor did any have alternative future uses. The Company performs an impairment test on IPR&D assets at least annually, or more frequently if events or changes in circumstances indicate that IPR&D assets may be impaired. As a result of the discontinuation of the Glemba program, the Company concluded that the Glemba IPR&D asset was fully impaired and a non-cash impairment charge of $11.8 million was recorded in the first quarter of 2018. Due to the nature of IPR&D projects, the Company may experience future delays or failures to obtain regulatory approvals to conduct clinical trials, failures of such clinical trials or other failures to achieve a commercially viable product, and as a result, may recognize further impairment losses in the future. Goodwill The Company evaluated goodwill for potential impairment due to the discontinuation of the Glemba program. The carrying amount of the Company was compared to the Company’s fair value. The Company’s fair value assessment reflected a number of significant management assumptions and estimates including the Company’s probability forecasts for pipeline assets, income taxes, capital expenditures, market premium and changes in working capital requirements. Changes in these assumptions and/or discount rates could materially impact the Company’s conclusions. Through this assessment, it was determined that the carrying amount of the Company exceeded its fair value by over $91.0 million. As such, the full goodwill asset was considered impaired and a charge of $91.0 million was recorded during the first quarter of 2018.

Other Assets

Other Assets	3 Months Ended
	Mar. 31, 2019
Other Assets
Other Assets	(7) Other Assets In 2016, the Company entered into a research and collaboration agreement with an undisclosed private company to access novel technologies and paid $3.5 million to support research activities and make an investment in the private company. The Company recorded $1.8 million to other assets related to this investment and $1.7 million was recorded to research and development expense over the term of the research activities. The stock of the private company does not have a readily determinable fair value, and therefore it is measured at cost less impairment, if any. Based on information received in April 2019, it was determined that there was a deterioration of the private company’s financial condition due to a working capital deficiency and an inability to secure additional funding as of March 31, 2019. Therefore, the Company concluded that the investment is impaired, and a non-cash impairment charge of $1.8 million was recorded for the three months ended March 31, 2019.

Other Long-Term Liabilities

Other Long-Term Liabilities	3 Months Ended
	Mar. 31, 2019
Other Long-Term Liabilities
Other Long-Term Liabilities	(8) Other Long-Term Liabilities Other long-term liabilities include the following: March 31, 2019 December 31, 2018 (In thousands) Net Deferred Tax Liabilities Related to IPR&D (Note 13) $ 3,007 $ 3,007 Deferred Income From Sale of Tax Benefits 4,014 4,218 Other — 1,083 Contingent Milestones (Note 3) 15,298 13,779 Deferred Revenue (Note 12) 754 1,586 Total 23,073 23,673 Less Current Portion (2,777) (4,526) Long-Term Portion $ 20,296 $ 19,147 In November 2015 and December 2014, the Company received approval from the New Jersey Economic Development Authority and agreed to sell New Jersey tax benefits of $9.8 million and $1.9 million to an independent third party for $9.2 million and $1.8 million, respectively. Under the agreement, the Company must maintain a base of operations in New Jersey for five years or the tax benefits must be paid back on a pro-rata basis based on the number of years completed. The Company recognized $0.2 million and $0.4 million in other income related to the sale of these tax benefits during the three months ended March 31, 2019 and 2018, respectively.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2019
Stockholders' Equity
Stockholders' Equity	(9) Stockholders’ Equity In May 2016, the Company entered into an agreement with Cantor Fitzgerald & Co. (“Cantor”) to allow the Company to issue and sell shares of its common stock having an aggregate offering price of up to $60.0 million from time to time through Cantor, acting as agent. In November 2017, the Company filed a prospectus supplement registering the offer and sale of shares of common stock of up to an additional $75.0 million under the agreement with Cantor. During the three months ended March 31, 2019, the Company issued 883,569 shares of common stock under this controlled equity offering sales agreement with Cantor resulting in net proceeds of $4.2 million after deducting commission and offering expenses. At March 31, 2019, the Company had $33.3 million remaining in aggregate gross offering price available under the Cantor agreement. In April 2019, the Company issued 924,167 shares of its common stock resulting in net proceeds to the Company of $4.1 million. The changes in Stockholders’ Equity during the three months ended March 31, 2019 and 2018 are summarized below: Accumulated Common Common Additional Other Total Stock Stock Par Paid-In Comprehensive Accumulated Stockholders’ Shares Value Capital Income Deficit Equity (In thousands, except share amounts) Consolidated Balance at December 31, 2017 9,234,693 9 1,046,313 2,564 (812,517) 236,369 Shares Issued under Stock Option and Employee Stock Purchase Plans 9,453 — 374 — — 374 Shares Issued in Connection with Cantor Agreement 312,802 — 11,689 — — 11,689 Shares Issued in Connection with Kolltan Severance 971 — 38 — — 38 Share-Based Compensation — — 2,488 — — 2,488 Unrealized Loss on Marketable Securities — — — (5) — (5) Adoption of ASC 606 — — — — 1,261 1,261 Net Loss — — — — (118,132) (118,132) Consolidated Balance at March 31, 2018 9,557,919 9 1,060,902 2,559 (929,388) 134,082 Accumulated Common Common Additional Other Total Stock Stock Par Paid-In Comprehensive Accumulated Stockholders’ Shares Value Capital Income Deficit Equity (In thousands, except share amounts) Consolidated Balance at December 31, 2018 11,957,635 12 1,083,903 2,583 (962,438) 124,060 Shares Issued under Stock Option and Employee Stock Purchase Plans 3,507 — 9 — — 9 Shares Issued in Connection with Cantor Agreement 883,569 1 4,150 — — 4,151 Share-Based Compensation — — 1,693 — — 1,693 Unrealized Gain on Marketable Securities — — — 19 — 19 Net Loss — — — — (17,239) (17,239) Consolidated Balance at March 31, 2019 12,844,711 13 1,089,755 2,602 (979,677) 112,693

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2019
Stock-Based Compensation
Stock-Based Compensation	(10) Stock-Based Compensation A summary of stock option activity for the three months ended March 31, 2019 is as follows: Weighted Weighted Average Average Exercise Remaining Price Contractual Shares Per Share Term (In Years) Options Outstanding at December 31, 2018 866,132 $ 93.70 7.1 Granted 900 4.88 Exercised — — Canceled (30,928) 125.69 Options Outstanding at March 31, 2019 836,104 92.42 7.0 Options Vested and Expected to Vest at March 31, 2019 800,868 95.77 6.9 Options Exercisable at March 31, 2019 416,737 163.47 5.2 Shares Available for Grant Under the 2008 Plan 387,138 The weighted average grant-date fair value of stock options granted during the three month period ended March 31, 2019 was $3.67. Stock-based compensation expense for the three months ended March 31, 2019 and 2018 was recorded as follows: Three months ended March 31, 2019 2018 (In thousands) Research and development $ 756 $ 1,311 General and administrative 937 1,177 Total stock-based compensation expense $ 1,693 $ 2,488 The fair values of employee and director stock options granted during the three months ended March 31, 2019 and 2018 were valued using the Black-Scholes option pricing model with the following assumptions: Three months ended March 31, 2019 2018 Expected stock price volatility 91 % 73 % Expected option term 6.0 Years Years Risk-free interest rate 2.5 % 2.8 % Expected dividend yield None None

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	3 Months Ended
	Mar. 31, 2019
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income	(11) Accumulated Other Comprehensive Income The changes in accumulated other comprehensive income, which is reported as a component of stockholders’ equity, for the three months ended March 31, 2019 are summarized below: Unrealized Gain/(Loss) on Marketable Foreign Securities Currency Items Total (In thousands) Balance at December 31, 2018 $ (13) $ 2,596 $ 2,583 Other comprehensive loss 19 — 19 Balance at March 31,2019 $ 6 $ 2,596 $ 2,602 No amounts were reclassified out of accumulated other comprehensive income during the three months ended March 31, 2019.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2019
Revenue
Revenue	(12) Revenue Product Development and Licensing Revenue The Company’s primary product development and licensing revenue is associated with a clinical collaboration agreement with BMS entered into in 2014 to evaluate the safety, tolerability and preliminary efficacy of varlilumab and Opdivo®, BMS’s PD-1 immune checkpoint inhibitor, in a Phase 1/2 study. Under this agreement, BMS made an upfront payment to Celldex of $5.0 million and provides funding for 50% of the external costs incurred by the Company in connection with the clinical trial. The Company recorded $0.1 million and $0.9 million in revenue related to this agreement during the three months ended March 31, 2019 and 2018, respectively. Contract and Grants Revenue The Company has entered into agreements with Rockefeller University and Duke University pursuant to which the Company performs manufacturing and research and development services on a time-and-materials basis. The Company recognized $1.2 million and $0.8 million in revenue for labor hours and direct costs incurred under these agreements during the three months ended March 31, 2019 and 2018, respectively. The Company has entered into fixed-fee manufacturing and research and development arrangements with the International AIDS Vaccine Initiative and Frontier Biotechnologies, Inc. The Company recognized $0.1 million and $2.3 million in revenue under these agreements during the three months ended March 31, 2019 and 2018, respectively. Contract Assets and Liabilities At December 31, 2018 and March 31, 2019, the Company’s right to consideration under all contracts was considered unconditional, and as such, there were no recorded contract assets. At December 31, 2018 and March 31, 2019, the Company had $1.6 million and $0.8 million in contract liabilities recorded, respectively. Revenue recognized from contract liabilities as of December 31, 2018 during the three months ended March 31, 2019 was $0.8 million.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2019
Income Taxes
Income Taxes	(13) Income Taxes The Company has evaluated the positive and negative evidence bearing upon the realizability of its net deferred tax assets and considered its history of losses, ultimately concluding that it is “more likely than not” that the Company will not recognize the benefits of federal, state and foreign deferred tax assets and, as such, has maintained a full valuation allowance on its deferred tax assets as of March 31, 2019 and December 31, 2018. The net deferred tax liability of $3.0 million at March 31, 2019 and December 31, 2018 relates to the temporary differences associated with the IPR&D intangible assets acquired in previous business combinations and is not deductible for tax purposes. As a result of the discontinuation of the Glemba program, the Company recorded a $0.8 million non-cash income tax benefit during the first quarter of 2018. Massachusetts, New Jersey, Connecticut and Australia are the jurisdictions in which the Company primarily operates or has operated and has income tax nexus. The Company is not currently under examination by these or any other jurisdictions for any tax year.

Net Loss Per Share

Net Loss Per Share	3 Months Ended
	Mar. 31, 2019
Net Loss Per Share
Net Loss Per Share	(14) Net Loss Per Share Basic net loss per common share is based upon the weighted-average number of common shares outstanding during the period, excluding restricted stock that has been issued but is not yet vested. Diluted net loss per common share is based upon the weighted-average number of common shares outstanding during the period plus additional weighted -average potentially dilutive common shares outstanding during the period when the effect is dilutive. The potentially dilutive common shares that have not been included in the net loss per common share calculations because the effect would have been anti-dilutive are as follows: Three Months Ended March 31, 2019 2018 Stock Options 836,104 630,445 Restricted Stock 3,552 6,445 839,656 636,890

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
Significant Accounting Policies
Newly Adopted Accounting Pronouncements	Newly Adopted Accounting Pronouncements On January 1, 2019, the Company adopted a new U.S. GAAP accounting standard which requires that all lessees recognize the assets and liabilities that arise from leases on the balance sheet and disclose qualitative and quantitative information about its leasing arrangements. The new standard was adopted using the modified retrospective transition method, which requires the Company to apply the standard as of the effective date and does not require restatement of prior periods. The Company elected to apply the package of practical expedients, which allowed the Company to not reassess: (i) whether expired or existing contracts contain leases; (ii) lease classification for any expired or existing leases; and (iii) initial direct costs for any existing leases. Adoption of this standard did not have a material impact on the Company's Consolidated Statement of Operations and Comprehensive Loss or Statement of Cash Flow, however, upon adoption, the Company recorded right-of-use assets of $3.8 million and lease liabilities of $4.7 million on its Consolidated Balance Sheet related to the Company's operating leases. The difference between the right-of-use assets and lease liabilities recorded upon adoption is due to certain adjustments required to the right-of-use assets for prepaid rent and accrued termination expenses. Refer to Note 5 “Leases” for the Company’s updated lease accounting policy and disclosures.
Recent Accounting Pronouncements	Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on the Company’s consolidated financial statements upon adoption. In June 2016, the FASB issued guidance on the Measurement of Credit Losses on Financial Instruments. The guidance requires that credit losses be reported using an expected losses model rather than the incurred losses model that is currently used, and establishes additional disclosures related to credit risks. For available-for-sale debt securities with unrealized losses, the standard now requires allowances to be recorded instead of reducing the amortized cost of the investment. This standard will be effective for the Company on January 1, 2020. We are currently evaluating the potential impact that this standard may have on the Company's consolidated financial statements and related disclosures. In August 2018, the FASB issued amendments that modify certain disclosure requirements for fair value measurements. The amendments become effective, including interim periods, beginning January 1, 2020. Early adoption, of all the amendments or only the provisions that eliminate or modify the requirements, is permitted. The adoption of this new guidance is not expected to have a material impact on the Company's consolidated financial statements and related disclosures. In November 2018, the FASB issued guidance to clarify the interaction between the accounting guidance for collaborative arrangements and revenue from contracts with customers. The amendments become effective, including interim periods, beginning January 1, 2020. Early adoption, including adoption in an interim period, is permitted. This guidance is required to be applied retrospectively as of the date of our adoption of the new revenue standard on January 1, 2018. We are currently evaluating the timing of our adoption and the expected impact this guidance could have on our consolidated financial statements and related disclosures.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Measurements
Schedule of financial assets and liabilities subject to fair value measurements	As of March 31, 2019 Level 1 Level 2 Level 3 (In thousands) Assets: Money market funds and cash equivalents $ 21,432 — $ 21,432 — Marketable securities 53,535 — 53,535 — $ 74,967 — $ 74,967 — Liabilities: Kolltan acquisition contingent consideration $ 15,298 — — $ 15,298 $ 15,298 — — $ 15,298 As of December 31, 2018 Level 1 Level 2 Level 3 (In thousands) Assets: Money market funds and cash equivalents $ 15,755 — $ 15,755 — Marketable securities 69,712 — 69,712 — $ 85,467 — $ 85,467 — Liabilities: Kolltan acquisition contingent consideration $ 13,779 — — $ 13,779 $ 13,779 — — $ 13,779
Schedule of the contingent consideration liabilities measured at fair value using Level 3 inputs	The following table reflects the activity for the Company’s contingent consideration liabilities measured at fair value using Level 3 inputs for the three months ended March 31, 2019 (in thousands): Other Liabilities: Contingent Consideration Balance at December 31, 2018 $ 13,779 Fair value adjustments included in operating expenses 1,519 Balance at March 31, 2019 $ 15,298

Marketable Securities (Tables)

Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2019
Marketable Securities
Summary of marketable securities, classified as available-for-sale	Gross Unrealized Amortized Fair Cost Gains Losses Value (In thousands) March 31, 2019 U.S. government and municipal obligations (maturing in one year or less) $ 17,641 $ 3 $ — $ 17,644 Corporate debt securities (maturing in one year or less) 35,888 4 (1) 35,891 Total Marketable Securities $ 53,529 $ 7 $ (1) $ 53,535 December 31,2018 U.S. government and municipal obligations (maturing in one year or less) $ 27,355 $ — $ (4) $ 27,351 Corporate debt securities (maturing in one year or less) 42,370 — (9) 42,361 Total Marketable Securities $ 69,725 $ — $ (13) $ 69,712

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases
Schedule of future minimum lease payments under non-cancellable leases	Remainder of 2019 $ 2,277 2020 2,171 2021 508 2022 746 2023 311 Total lease payments 6,013 Less imputed interest (781) Present value of operating lease liabilities $ 5,232
Schedule of operating lease obligations, including estimated variable lease obligations as per prior lease accounting guidance as of December 31, 2018	2019 $ 4,648 2020 3,140 Thereafter — Total lease payments $ 7,788

Other Long-Term Liabilities (Ta

Other Long-Term Liabilities (Tables)	3 Months Ended
	Mar. 31, 2019
Other Long-Term Liabilities
Schedule of other long-term liabilities	March 31, 2019 December 31, 2018 (In thousands) Net Deferred Tax Liabilities Related to IPR&D (Note 13) $ 3,007 $ 3,007 Deferred Income From Sale of Tax Benefits 4,014 4,218 Other — 1,083 Contingent Milestones (Note 3) 15,298 13,779 Deferred Revenue (Note 12) 754 1,586 Total 23,073 23,673 Less Current Portion (2,777) (4,526) Long-Term Portion $ 20,296 $ 19,147

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2019
Shareholders' Equity
Schedule of Shareholder's equity	Accumulated Common Common Additional Other Total Stock Stock Par Paid-In Comprehensive Accumulated Stockholders’ Shares Value Capital Income Deficit Equity (In thousands, except share amounts) Consolidated Balance at December 31, 2017 9,234,693 9 1,046,313 2,564 (812,517) 236,369 Shares Issued under Stock Option and Employee Stock Purchase Plans 9,453 — 374 — — 374 Shares Issued in Connection with Cantor Agreement 312,802 — 11,689 — — 11,689 Shares Issued in Connection with Kolltan Severance 971 — 38 — — 38 Share-Based Compensation — — 2,488 — — 2,488 Unrealized Loss on Marketable Securities — — — (5) — (5) Adoption of ASC 606 — — — — 1,261 1,261 Net Loss — — — — (118,132) (118,132) Consolidated Balance at March 31, 2018 9,557,919 9 1,060,902 2,559 (929,388) 134,082 Accumulated Common Common Additional Other Total Stock Stock Par Paid-In Comprehensive Accumulated Stockholders’ Shares Value Capital Income Deficit Equity (In thousands, except share amounts) Consolidated Balance at December 31, 2018 11,957,635 12 1,083,903 2,583 (962,438) 124,060 Shares Issued under Stock Option and Employee Stock Purchase Plans 3,507 — 9 — — 9 Shares Issued in Connection with Cantor Agreement 883,569 1 4,150 — — 4,151 Share-Based Compensation — — 1,693 — — 1,693 Unrealized Gain on Marketable Securities — — — 19 — 19 Net Loss — — — — (17,239) (17,239) Consolidated Balance at March 31, 2019 12,844,711 13 1,089,755 2,602 (979,677) 112,693

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2019
Stock-Based Compensation
Summary of stock option activity	Weighted Weighted Average Average Exercise Remaining Price Contractual Shares Per Share Term (In Years) Options Outstanding at December 31, 2018 866,132 $ 93.70 7.1 Granted 900 4.88 Exercised — — Canceled (30,928) 125.69 Options Outstanding at March 31, 2019 836,104 92.42 7.0 Options Vested and Expected to Vest at March 31, 2019 800,868 95.77 6.9 Options Exercisable at March 31, 2019 416,737 163.47 5.2 Shares Available for Grant Under the 2008 Plan 387,138
Schedule of stock-based compensation expense	Three months ended March 31, 2019 2018 (In thousands) Research and development $ 756 $ 1,311 General and administrative 937 1,177 Total stock-based compensation expense $ 1,693 $ 2,488
Schedule of assumptions used for the fair value of employee stock options granted	Three months ended March 31, 2019 2018 Expected stock price volatility 91 % 73 % Expected option term 6.0 Years Years Risk-free interest rate 2.5 % 2.8 % Expected dividend yield None None

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2019
Accumulated Other Comprehensive Income
Summary of changes in accumulated other comprehensive income	Unrealized Gain/(Loss) on Marketable Foreign Securities Currency Items Total (In thousands) Balance at December 31, 2018 $ (13) $ 2,596 $ 2,583 Other comprehensive loss 19 — 19 Balance at March 31,2019 $ 6 $ 2,596 $ 2,602

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2019
Net Loss Per Share
Schedule of potentially dilutive common shares that have not been included in the net loss per common share calculations because the effect would have been anti-dilutive	Three Months Ended March 31, 2019 2018 Stock Options 836,104 630,445 Restricted Stock 3,552 6,445 839,656 636,890

Basis of Presentation (Details)

Basis of Presentation (Details) $ in Thousands	Feb. 08, 2019	Mar. 31, 2019USD ($)	Mar. 31, 2018USD ($)
Basis of Presentation
Cash, cash equivalents and marketable securities		$ 85,100
Net loss		(17,239)	$ (118,132)
Net cash used in operations		$ 13,233	$ 28,022
Reverse stock split	0.067

Significant Accounting Polici_3

Significant Accounting Policies - Newly Adopted Accounting Pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Jan. 01, 2019
Newly-Adopted Accounting Pronouncements
Lease, Practical Expedients, Package [true false]	true
Right-of-use assets	$ 4,445
Lease liabilities	5,232
ASC 842
Newly-Adopted Accounting Pronouncements
Right-of-use assets	1,400	$ 3,800
Lease liabilities	$ 1,400	$ 4,700

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair value | Level 3
Liabilities:
Kolltan acquisition contingent consideration	$ 15,298	$ 13,779
Fair Value Measurements | Level 2
Assets:
Money market funds and cash equivalents	21,432	15,755
Marketable securities	53,535	69,712
Total financial assets at fair value	74,967	85,467
Fair Value Measurements | Level 3
Liabilities:
Kolltan acquisition contingent consideration	15,298	13,779
Total financial liabilities at fair value	15,298	13,779
Fair Value Measurements | Fair value
Assets:
Money market funds and cash equivalents	21,432	15,755
Marketable securities	53,535	69,712
Total financial assets at fair value	74,967	85,467
Liabilities:
Kolltan acquisition contingent consideration	15,298	13,779
Total financial liabilities at fair value	$ 15,298	$ 13,779

Fair Value Measurements - Conti

Fair Value Measurements - Contingent Consideration Liabilities (Details) - Fair value - Level 3 $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Contingent consideration liabilities measured at fair value
Balance at beginning of period	$ 13,779
Fair value adjustments included in operating expenses	1,519
Balance at end of period	$ 15,298

Fair Value Measurements - Addit

Fair Value Measurements - Additional information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Nov. 29, 2016
Fair value measurements
Gain (loss) on fair value remeasurement of contingent consideration	$ (1,519)	$ 13,600
Kolltan | Specified development, regulatory approvals or sales-based milestones
Fair value measurements
Milestone payments			$ 127,500
Fair value
Fair value measurements
Assets level 1 to level 2 transfers	0
Assets level 2 to level 1 transfers	0
Liabilities level 1 to level 2 transfers	0
Liabilities level 2 to level 1 transfers	0
Asset transfer out of level 3	0
Asset transfer into level 3	0
Liabilities transfers out of level 3	0
Liabilities transfers into level 3	$ 0

Marketable Securities (Details)

Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Amortized Cost
Amortized Cost	$ 53,529	$ 69,725
Gross Unrealized Gains
Gross Unrealized Gains	7
Gross Unrealized Losses
Gross Unrealized Losses	(1)	(13)
Fair Value
Fair Value	53,535	69,712
U.S. government and municipal obligations
Amortized Cost
Maturing in one year or less	17,641	27,355
Gross Unrealized Gains
Maturing in one year or less	3
Gross Unrealized Losses
Maturing in one year or less		(4)
Fair Value
Maturing in one year or less	17,644	27,351
Corporate debt securities
Amortized Cost
Maturing in one year or less	35,888	42,370
Gross Unrealized Gains
Maturing in one year or less	4
Gross Unrealized Losses
Maturing in one year or less	(1)	(9)
Fair Value
Maturing in one year or less	$ 35,891	$ 42,361

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Marketable Securities
Number of investment-grade securities in unrealized loss position over 12 months	$ 0	$ 0
Accrued interest	$ 100	$ 100

Leases (Details)

Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)ft²	Jan. 01, 2019USD ($)
Leases
Lessor, Operating Lease, Existence of Option to Extend [true false]	true
Lessor, Operating Lease, Existence of Option to Terminate [true false]	true
Lease to eliminate | ft²	16,200
lease to extend | ft²	33,400
lease to additional term	5 years
lease to termination term	3 years
Lease liabilities	$ 5,232
Right-of-use assets	$ 4,445
Lease term related to amendment	3 years
Operating lease expense	$ 700
Variable lease expense	400
Operating lease payments	$ 900
Weighted-average remaining lease term	2 years
Weighted-average discount rate	11.30%
ASC 842
Leases
Lease liabilities	$ 1,400	$ 4,700
Right-of-use assets	$ 1,400	$ 3,800

Leases - Future minimum lease p

Leases - Future minimum lease payments under non-cancellable leases (Details) $ in Thousands	Mar. 31, 2019USD ($)
Operating lease liabilities, payments due
Remainder of 2019	$ 2,277
2020	2,171
2021	508
2022	746
2023	311
Total lease payments	6,013
Less imputed interest	(781)
Present value of operating lease liabilities	$ 5,232

Leases - Operating lease obliga

Leases - Operating lease obligations under prior lease accounting guidance (Details) $ in Thousands	Dec. 31, 2018USD ($)
Operating lease obligations under prior lease accounting guidance
2019	$ 4,648
2020	3,140
Total lease payments	$ 7,788

Intangible Assets and Goodwill

Intangible Assets and Goodwill - Intangible Assets, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Intangible assets
Amortization of Acquired Intangible Assets	$ 0	$ 224
Indefinite-lived intangible assets	$ 48,700	48,700
IPR&D
Intangible assets
Non-cash impairment charge, indefinite-lived		11,800
License Rights
Intangible assets
Non-cash impairment charge, finite lived		$ 6,900

Intangible Assets and Goodwil_2

Intangible Assets and Goodwill - Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2018
Goodwill
Goodwill asset impaired	$ 90,976
Glemba
Goodwill
Amount of carrying amount in excess of fair value amount		$ 91,000
Goodwill asset impaired	$ 91,000

Other Assets (Details)

Other Assets (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2016
Other Assets
Cash paid to support research activities and investment in private company		$ 3.5
Other assets related to investment in undisclosed private company		1.8
Other assets related to research and development expense		$ 1.7
Non-cash impairment charge on investments	$ 1.8

Other Long-Term Liabilities (De

Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Other Long-Term Liabilities
Net Deferred Tax Liabilities Related to IPR&P (Note 13)	$ 3,007	$ 3,007
Deferred Income From Sale of Tax Benefits	4,014	4,218
Other		1,083
Contingent Milestones (Note 3)	15,298	13,779
Deferred Revenue	754	1,586
Total	23,073	23,673
Less Current Portion	(2,777)	(4,526)
Long-Term Portion	$ 20,296	$ 19,147

Other Long-Term Liabilities- Ne

Other Long-Term Liabilities- New Jersey tax benefits (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended
	Nov. 30, 2015	Dec. 31, 2014	Mar. 31, 2019	Mar. 31, 2018
Investment and other income			$ 702	$ 780
New Jersey tax benefits
Amount of tax benefit	$ 9,800	$ 1,900
Proceeds from sale of tax credits	$ 9,200	$ 1,800
Base of operations requirement (in years)			5 years
Investment and other income			$ 200	$ 400

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ in Thousands	1 Months Ended			3 Months Ended
	Apr. 30, 2019	Nov. 30, 2017	May 31, 2016	Mar. 31, 2019	Mar. 31, 2018
Common Stock
Aggregate offering price stock sale			$ 60,000
Additional offering price stock sale authorized		$ 75,000
Net proceeds from sale of common stock				$ 4,151	$ 11,689
Common Stock
Common Stock
Shares Issued in Connection with Cantor Agreement (in shares)				883,569	312,802
Aggregate gross offering price available				$ 33,300
Net proceeds from sale of common stock				$ 4,200
Common Stock | Subsequent Event
Common Stock
Common stock issued (in shares)	924,167
Net proceeds from sale of common stock	$ 4,100

Stockholders' Equity - Changes

Stockholders' Equity - Changes in Stockholders' equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Increase (Decrease) in Stockholders' Equity
Period Start Balance	$ 124,060	$ 236,369
Balance (in shares)	11,957,635
Shares Issued under Stock Option and Employee Stock Purchase Plans	$ 9	374
Shares Issued in Connection with Cantor Agreement	4,151	11,689
Shares Issued in Connection with Kolltan Severance		38
Share-Based Compensation	1,693	2,488
Unrealized Gain (Loss) on Marketable Securities	19	(5)
Net Loss	(17,239)	(118,132)
Period End Balance	$ 112,693	134,082
Balance (in shares)	12,844,711
ASC 606
Increase (Decrease) in Stockholders' Equity
Adoption of ASC		1,261
Common Stock
Increase (Decrease) in Stockholders' Equity
Period Start Balance	$ 12	$ 9
Balance (in shares)	11,957,635	9,234,693
Shares Issued under Stock Option and Employee Stock Purchase Plans (in shares)	3,507	9,453
Shares Issued in Connection with Cantor Agreement	$ 1
Shares Issued in Connection with Cantor Agreement (in shares)	883,569	312,802
Shares Issued in Connection with Kolltan Severance (in shares)		971
Period End Balance	$ 13	$ 9
Balance (in shares)	12,844,711	9,557,919
Additional Paid-In Capital
Increase (Decrease) in Stockholders' Equity
Period Start Balance	$ 1,083,903	$ 1,046,313
Shares Issued under Stock Option and Employee Stock Purchase Plans	9	374
Shares Issued in Connection with Cantor Agreement	4,150	11,689
Shares Issued in Connection with Kolltan Severance		38
Share-Based Compensation	1,693	2,488
Period End Balance	1,089,755	1,060,902
Accumulated Other Comprehensive Income
Increase (Decrease) in Stockholders' Equity
Period Start Balance	2,583	2,564
Unrealized Gain (Loss) on Marketable Securities	19	(5)
Period End Balance	2,602	2,559
Accumulated Deficit
Increase (Decrease) in Stockholders' Equity
Period Start Balance	(962,438)	(812,517)
Net Loss	(17,239)	(118,132)
Period End Balance	$ (979,677)	(929,388)
Accumulated Deficit | ASC 606
Increase (Decrease) in Stockholders' Equity
Adoption of ASC		$ 1,261

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock option activity (Details) - Stock options - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Shares
Options Outstanding at beginning of the period (in shares)	866,132
Granted (in shares)	900
Canceled (in shares)	(30,928)
Options Outstanding at the end of the period (in shares)	836,104	866,132
Options Vested and Expected to Vest at the end of the period (in shares)	800,868
Options Exercisable at the end of the period (in shares)	416,737
Shares Available for Grant Under the 2008 Plan	387,138
Weighted Average Exercise Price Per Share
Options Outstanding at beginning of the period (in dollars per share)	$ 93.70
Granted (in dollars per share)	4.88
Canceled (in dollars per share)	125.69
Options Outstanding at the end of the period (in dollars per share)	92.42	$ 93.70
Options Vested and Expected to Vest at the end of the period (in dollars per share)	95.77
Options Exercisable at the end of the period (in dollars per share)	$ 163.47
Weighted Average Remaining Contractual Term (In Years)
Options Outstanding at the end of the period	7 years	7 years 1 month 6 days
Options Vested and Expected to Vest at the end of the period	6 years 10 months 24 days
Options Exercisable at the end of the period	5 years 2 months 12 days

Stock-Based Compensation - Expe

Stock-Based Compensation - Expenses (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Stock-based compensation expense
Stock-based compensation expense	$ 1,693	$ 2,488
Stock options
Stock-based compensation expense
Weighted average grant-date fair value (in dollars per share)	$ 3.67
Research and development
Stock-based compensation expense
Stock-based compensation expense	$ 756	1,311
General and administrative
Stock-based compensation expense
Stock-based compensation expense	$ 937	$ 1,177

Stock-Based Compensation - Valu

Stock-Based Compensation - Valuation (Details)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Black-Scholes option with following assumptions:
Expected stock price volatility (as a percent)	91.00%	73.00%
Expected option term	6 years	6 years
Risk-free interest rate (as a percent)	2.50%	2.80%
Expected dividend yield (as a percent)	0.00%	0.00%

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Accumulated Other Comprehensive Income
Period Start Balance	$ 124,060
Period End Balance	112,693
Amounts reclassified from AOCI	0
Unrealized Gain/(Loss) on Marketable Securities
Accumulated Other Comprehensive Income
Period Start Balance	(13)
Other comprehensive loss	19
Period End Balance	6
Foreign Currency Items
Accumulated Other Comprehensive Income
Period Start Balance	2,596
Period End Balance	2,596
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income
Period Start Balance	2,583
Other comprehensive loss	19
Period End Balance	$ 2,602

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2014	Dec. 31, 2018
Revenue
Revenue recognized from contract liabilities	$ 800
Deferred Revenue	754			$ 1,586
Revenues	1,425	$ 4,068
Product Development and Licensing Agreements
Revenue
Revenues	129	992
Contracts and Grants
Revenue
Revenues	1,296	3,076
Bristol-Myers Squibb Company
Revenue
Deferred Revenue			$ 5,000
Reimbursement of external costs (as percent)			50.00%
Revenues	100	900
IAVI & Frontier
Revenue
Revenues	100	2,300
Rockefeller and Duke
Revenue
Revenues	$ 1,200	$ 800

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2019	Dec. 31, 2018
Net Deferred Tax Liabilities related to IPR&D		$ 3,007	$ 3,007
Income tax expense (benefit)	$ (765)
Glemba | IPR&D
Income tax expense (benefit)	$ (800)

Net Loss Per Share (Details)

Net Loss Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net loss per share
Potentially dilutive common shares not been included in net loss per common share calculations because the effect would have been anti-dilutive	839,656	636,890
Stock options
Net loss per share
Potentially dilutive common shares not been included in net loss per common share calculations because the effect would have been anti-dilutive	836,104	630,445
Restricted Stock
Net loss per share
Potentially dilutive common shares not been included in net loss per common share calculations because the effect would have been anti-dilutive	3,552	6,445