Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2016	Mar. 06, 2017	Jun. 30, 2016
Document and Entity Information
Entity Registrant Name	Celldex Therapeutics, Inc.
Entity Central Index Key	0000744218
Document Type	10-K
Document Period End Date	Dec. 31, 2016
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 435
Entity Common Stock, Shares Outstanding		123,213,438
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	FY

BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current Assets:
Cash and Cash Equivalents	$ 42,461	$ 72,108
Marketable Securities	147,315	217,781
Accounts and Other Receivables	1,784	970
Prepaid and Other Current Assets	4,009	4,077
Total Current Assets	195,569	294,936
Property and Equipment, Net	13,192	11,461
Intangible Assets, Net	81,487	20,794
Other Assets	2,134	1,428
Goodwill	90,976	8,965
Total Assets	383,358	337,584
Current Liabilities:
Accounts Payable	1,740	1,506
Accrued Expenses	28,657	24,316
Current Portion of Long-Term Liabilities	4,826	4,418
Total Current Liabilities	35,223	30,240
Other Long-Term Liabilities	82,704	17,239
Total Liabilities	117,927	47,479
Commitments and Contingent Liabilities (Notes 13 and 15)
Stockholders' Equity:
Convertible Preferred Stock, $.01 Par Value; 3,000,000 Shares Authorized; No Shares Issued and Outstanding at December 31, 2016 and 2015
Common Stock, $.001 Par Value; 297,000,000 Shares Authorized; 120,516,654 and 98,685,595 Shares Issued and Outstanding at December 31, 2016 and 2015, respectively	121	99
Additional Paid-In Capital	982,255	878,655
Accumulated Other Comprehensive Income	2,541	2,307
Accumulated Deficit	(719,486)	(590,956)
Total Stockholders' Equity	265,431	290,105
Total Liabilities and Stockholders' Equity	$ 383,358	$ 337,584

BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
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	120,516,654	98,685,595
Common Stock, Shares Outstanding	120,516,654	98,685,595

STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
REVENUE:
Product Development and Licensing Agreements	$ 2,174	$ 1,442	$ 838
Contracts and Grants	4,612	4,038	2,748
Total Revenue	6,786	5,480	3,586
OPERATING EXPENSE:
Research and Development	102,726	100,171	104,381
General and Administrative	35,979	33,837	20,622
Amortization of Acquired Intangible Assets	997	1,013	1,013
Total Operating Expense	139,702	135,021	126,016
Operating Loss	(132,916)	(129,541)	(122,430)
Investment and Other Income, Net	4,386	2,344	4,350
Net Loss	$ (128,530)	$ (127,197)	$ (118,080)
Basic and Diluted Net Loss Per Common Share (in dollars per share)	$ (1.27)	$ (1.31)	$ (1.32)
Shares Used in Calculating Basic and Diluted Net Loss per Share (in shares)	101,529	97,051	89,399
COMPREHENSIVE LOSS:
Net Loss	$ (128,530)	$ (127,197)	$ (118,080)
Other Comprehensive Income (Loss):
Foreign Currency Translation Adjustments		15	(5)
Unrealized Gain (Loss) on Marketable Securities	234	(298)	(73)
Comprehensive Loss	$ (128,296)	$ (127,480)	$ (118,158)

STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Total
Balance at Dec. 31, 2013	$ 89	$ 662,717	$ 2,668	$ (345,679)	$ 319,795
Balance (in shares) at Dec. 31, 2013	89,246,832
Increase (Decrease) in Stockholders' Equity
Shares Issued under Stock Option and Employee Stock Purchase Plans	$ 1	1,170			1,171
Shares Issued under Stock Option and Employee Stock Purchase Plans (in shares)	193,775
Shares Issued in Connection with Supply Agreement		2,000			2,000
Shares Issued in Connection with Supply Agreement (in shares)	152,172
Share-Based Compensation		6,852			6,852
Foreign Currency Translation Adjustments			(5)		(5)
Unrealized Gains (Losses) on Marketable Securities			(73)		(73)
Net Loss				(118,080)	(118,080)
Balance at Dec. 31, 2014	$ 90	672,739	2,590	(463,759)	211,660
Balance (in shares) at Dec. 31, 2014	89,592,779
Increase (Decrease) in Stockholders' Equity
Shares Issued under Stock Option and Employee Stock Purchase Plans	$ 1	4,310			4,311
Shares Issued under Stock Option and Employee Stock Purchase Plans (in shares)	755,316
Shares Issued in Underwritten Offering	$ 8	188,832			188,840
Shares Issued in Underwritten Offering (in shares)	8,337,500
Share-Based Compensation		12,774			12,774
Foreign Currency Translation Adjustments			15		15
Unrealized Gains (Losses) on Marketable Securities			(298)		(298)
Net Loss				(127,197)	(127,197)
Balance at Dec. 31, 2015	$ 99	878,655	2,307	(590,956)	$ 290,105
Balance (in shares) at Dec. 31, 2015	98,685,595				98,685,595
Increase (Decrease) in Stockholders' Equity
Shares Issued under Stock Option and Employee Stock Purchase Plans	$ 1	534			$ 535
Shares Issued under Stock Option and Employee Stock Purchase Plans (in shares)	158,152
Shares Issued in Connection with Cantor Agreement	$ 3	13,943			13,946
Shares Issued in Connection with Cantor Agreement (in shares)	3,303,800
Shares Issued in Connection with the Kolltan Acquisition	$ 18	73,379			73,397
Shares Issued in Connection with the Kolltan Acquisition (in shares)	18,257,996
Shares Issued in Connection with Kolltan Severance		427			427
Shares Issued in Connection with Kolltan Severance (in shares)	111,111
Share-Based Compensation		15,317			15,317
Unrealized Gains (Losses) on Marketable Securities			234		234
Net Loss				(128,530)	(128,530)
Balance at Dec. 31, 2016	$ 121	$ 982,255	$ 2,541	$ (719,486)	$ 265,431
Balance (in shares) at Dec. 31, 2016	120,516,654				120,516,654

STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash Flows From Operating Activities:
Net Loss	$ (128,530)	$ (127,197)	$ (118,080)
Adjustments to Reconcile Net Loss to Net Cash Used in Operating Activities:
Depreciation and Amortization	3,095	2,998	2,388
Amortization of Intangible Assets	997	1,013	1,013
Amortization and Premium of Marketable Securities, Net	926	350	95
Realized Gain on Sales and Maturities of Marketable Securities			(11)
Loss on Sale or Disposal of Assets	81		6
Stock-Based Compensation Expense	15,317	12,774	6,852
Non-Cash Expense	1,638	288	72
Changes in Operating Assets and Liabilities:
Accounts and Other Receivables	(814)	(543)	62
Prepaid and Other Current Assets	1,320	(653)	(2,026)
Other Assets	(89)	6	65
Accounts Payable and Accrued Expenses	(4,970)	4,875	1,450
Other Liabilities	(2,007)	7,202	6,577
Net Cash Used in Operating Activities	(113,036)	(98,887)	(101,537)
Cash Flows From Investing Activities:
Sales and Maturities of Marketable Securities	242,792	161,090	109,232
Purchases of Marketable Securities	(173,925)	(206,405)	(148,314)
Investment in Other	(1,801)
Cash Acquired in Kolltan Acquisition, net	4,592
Acquisition of Property and Equipment	(2,751)	(4,876)	(1,929)
Net Cash Provided by (Used in) Investing Activities	68,907	(50,191)	(41,011)
Cash Flows From Financing Activities:
Net Proceeds from Stock Issuances	13,946	188,840
Proceeds from Issuance of Stock from Employee Benefit Plans	536	4,311	1,171
Net Cash Provided by Financing Activities	14,482	193,151	1,171
Effect of Exchange Rate Changes on Cash and Cash Equivalents		15	(5)
Net (Decrease) Increase in Cash and Cash Equivalents	(29,647)	44,088	(141,382)
Cash and Cash Equivalents at Beginning of Period	72,108	28,020	169,402
Cash and Cash Equivalents at End of Period	42,461	72,108	28,020
Non-cash Investing Activities
Accrued construction in progress	159	$ 75	$ 1,027
Non-cash Supplemental Disclosure
Shares issued to former Kolltan executive for settlement of severance	426
Shares issued in connection with Kolltan Acquisition	$ 73,397

NATURE OF BUSINESS AND OVERVIEW	12 Months Ended
NATURE OF BUSINESS AND OVERVIEW	Dec. 31, 2016
NATURE OF BUSINESS AND OVERVIEW
NATURE OF BUSINESS AND OVERVIEW	(1) NATURE OF BUSINESS AND OVERVIEW Celldex Therapeutics, Inc. (the "Company" or "Celldex") is a biopharmaceutical company focused on the development and commercialization of several immunotherapy technologies for the treatment of cancer and other difficult-to-treat diseases. The Company currently has seven drug candidates in clinical development including glembatumumab vedotin (also referred to as CDX-011), varlilumab (also referred to as CDX-1127), CDX-0158, CDX-3379, CDX-1401, CDX-301 and CDX-014. As more fully discussed in Note 17, on November 29, 2016, the Company acquired (the "Kolltan Acquisition") Kolltan Pharmaceuticals, Inc. ("Kolltan"), a privately held clinical-stage biotechnology company based in New Haven, Connecticut in accordance with the Agreement and Plan of Merger dated as of November 1, 2016 (the "Merger Agreement"). Under the terms of the Merger Agreement, Kolltan's investors received, in exchange for their share and debt interests in Kolltan, an aggregate of 18,257,996 shares of Celldex's common stock. In addition, following closing, certain officers of Kolltan will receive an aggregate of 437,901 shares of Celldex's common stock in lieu of cash severance obligations, less tax withholdings. In December 2016, the Company issued 111,111 shares of Celldex's common stock as partial payment of this obligation. In addition, in the event that certain specified preclinical and clinical development milestones related to Kolltan's development programs and/or Celldex's development programs and certain commercial milestones related to Kolltan's drug candidates are achieved, Celldex will be required to pay Kolltan's stockholders milestone payments of up to $172.5 million, which milestone payments may be made, at Celldex's sole election, in cash, in shares of Celldex's common stock or a combination of both, subject to NASDAQ listing requirements and provisions of the Merger Agreement. The number of shares of Celldex common stock issuable in connection with a milestone payment, if any, will be determined based on the average closing price per share of Celldex common stock for the five trading day period ending three calendar days prior to the achievement of such milestone. Pursuant to applicable NASDAQ listing rules, Celldex is required to obtain stockholder approval of such issuances of Celldex's common stock to the extent that such issuances exceed 19.9% of its common stock outstanding prior to the merger. If Celldex does not obtain stockholder approval of such common stock issuances, Celldex may elect to pay the milestone consideration in cash to maintain compliance with applicable NASDAQ listing standards. Celldex may still decide to pay cash even if Celldex obtains stockholder approval although it is required to maintain a certain percentage of the overall consideration paid in Celldex common stock to satisfy certain tax requirements under the Merger Agreement. At December 31, 2016, the Company had cash, cash equivalents and marketable securities of $189.8 million. The Company has had recurring losses and incurred a loss of $128.5 million for the year ended December 31, 2016. Net cash used in operations for the year ended December 31, 2016 was $113.0 million. The Company believes that the cash, cash equivalents and marketable securities at March 14, 2017 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. 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 may decide to pay those milestone payments in cash. Further, if the Company does not obtain shareholder approval to issue shares in lieu of cash payments, the Company would need to make those payments in cash in order to meet its NASDAQ listing requirements. If the Company is unable to raise the funds necessary to meet its long-term liquidity needs, it may have to delay or discontinue the development of one or more programs, discontinue or delay on-going 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.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

12 Months Ended

Dec. 31, 2016

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

(2) SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation

Following the Kolltan Acquisition, the consolidated financial statements reflect the financial position, results of operation and cash flows of the combined companies. Accordingly, this report reflects the financial condition as of December 31, 2016 and the results of operations and cash flows for the period from the Kolltan Acquisition on November 29, 2016 through December 31, 2016. On December 31, 2016, the Company completed the merger of Kolltan with and into Celldex pursuant to a short-form merger effected under Delaware law. As a result, the separate corporate existence of Kolltan has ceased and the Company has succeeded to all rights, privileges, powers and franchises of Kolltan.

On December 31, 2014, the Company's wholly-owned subsidiary, Celldex Research Corporation, merged into Celldex Therapeutics, Inc. In February 2016, the Company formed a wholly-owned subsidiary, Celldex Therapeutics Europe GmbH, in Zug, Switzerland. In July 2016, we formed a wholly-owned subsidiary, Celldex Australia Pty Ltd, in Brisbane, Australia. The statements of operations and comprehensive loss, of stockholders' equity, and of cash flows, are consolidated for the years ended December 31, 2016 and 2014. These consolidated financial statements reflect the operations of the Company and its wholly-owned subsidiary prior to the merger. All intercompany balances and transactions have been eliminated in consolidation. The Company operates in one segment, which is the business of development, manufacturing and commercialization of novel therapeutics for human health care.

Use of Estimates

The preparation of the financial statements in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP) requires management to make estimates and use assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the dates of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Cash and Cash Equivalents

The Company considers all highly liquid investments purchased with a maturity date of 90 days or less at the date of purchase to be cash equivalents. Cash equivalents consist principally of money market funds and debt securities.

Marketable Securities

The Company invests its excess cash balances in marketable securities including municipal bond securities, U.S. government agency securities, and high-grade corporate bonds. The Company classifies all of its marketable securities as current assets on the balance sheets because they are available-for-sale and available to fund current operations. Marketable securities are stated at fair value with their unrealized gains and losses included as a component of accumulated other comprehensive income (loss), which is a separate component of stockholders' equity, until such gains and losses are realized. If a decline in the fair value is considered other-than-temporary, based on available evidence, the unrealized loss is transferred from other comprehensive income (loss) to the statements of operations. Realized gains and losses are determined on the specific identification method and are included in investment and other income, net.

Concentration of Credit Risk and of Significant Customers and Suppliers

Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of cash, cash equivalents, marketable securities and accounts receivable. The Company invests its cash, cash equivalents and marketable securities in debt instruments and interest bearing accounts at major financial institutions in excess of insured limits. The Company mitigates credit risk by limiting the investment type and maturity to securities that preserve capital, maintain liquidity and have a high credit quality. The Company has not historically experienced credit losses from its accounts receivable and therefore has not established an allowance for doubtful accounts.

Revenue from Rockefeller and BMS represented 40% and 31% for the year ended December 31, 2016, 62% and 24% for the year ended December 31, 2015, and 75% and 20% for the year ended December 31, 2014, of total Company revenue, respectively.

The Company relies on contract manufacturing organizations (CMO) to manufacture drug substance and drug product for its late-stage clinical study of glembatumumab vedotin as well as for future commercial supplies. The Company also relies on CMOs for supply of raw materials as well as filling, packaging, storage and shipping of drug product. These clinical studies would be adversely affected by a significant interruption in the supply of glembatumumab vedotin. The Company also relies on third-party collaborators to develop companion diagnostic tests for certain of its drug candidates, including glembatumumab vedotin.

Fair Value Measurements

The Company has certain assets and liabilities that are measured at fair value in the financial statements. The Company seeks to maximize the use of observable inputs (market data obtained from sources independent from the Company) and to minimize the use of unobservable inputs (the Company's assumptions about how market participants would price assets and liabilities) when measuring the fair value of its assets and liabilities. These assets and liabilities are classified into one of three levels of the following fair value hierarchy as defined by U.S. GAAP:

Level 1: Observable inputs such as quoted prices in active markets for identical assets or liabilities. An active market for an asset or liability is a market in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis.

Level 2: Observable inputs other than Level 1 prices, such as quoted prices in active markets for similar assets or liabilities and quoted prices for identical assets or liabilities in markets that are not active.

Level 3: Unobservable inputs based on the Company's assessment of the assumptions that market participants would use in pricing the asset or liability.

Property and Equipment

Property and equipment is stated at cost and depreciated over the estimated useful lives of the related assets using the straight-line method. Laboratory equipment and office furniture and equipment are depreciated over five years and computer equipment is depreciated over three years. Manufacturing equipment is amortized over seven to ten years. Leasehold improvements are amortized over the shorter of the estimated useful life or the non-cancelable term of the related lease, including any renewals that are reasonably assured of occurring. Property and equipment under construction is classified as construction in progress and is depreciated or amortized only after the asset is placed in service. Expenditures for maintenance and repairs are charged to expense whereas the costs of significant improvements which extend the life of the underlying asset are capitalized. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are eliminated and any resulting gain or loss is reflected in the Company's statements of operations and comprehensive loss.

The treatment of costs to construct property and equipment depends on the nature of the costs and the stage of construction. Costs incurred in the project planning, design, construction and installation phases are capitalized as part of the cost of the asset. The Company stops capitalizing these costs when the asset is substantially complete and ready for its intended use. For manufacturing property and equipment, the Company also capitalizes the cost of validating these assets for the underlying manufacturing process. The Company completes the capitalization of validation costs when the asset is substantially complete and ready for its intended use. Costs capitalized include incremental labor and fringe benefits, and direct consultancy services.

Business Combinations

The Company records the fair value of the consideration transferred to acquire a business to the tangible assets and identifiable intangible assets acquired and liabilities assumed on the basis of their fair values at the date of acquisition. The Company assesses the fair value of assets, including intangible assets such as in-process research and development (IPR&D), using a variety of methods including present value models. Each asset is measured at fair value from the perspective of a market participant. The method used to estimate the fair values of IPR&D assets incorporates significant assumptions regarding the estimates a market participant would make in order to evaluate an asset, including a market participant's assumptions regarding the probability of completing IPR&D projects, which would require obtaining regulatory approval for marketing of the associated drug candidate; a market participant's estimates regarding the timing of and the expected costs to complete IPR&D projects; a market participant's estimates of future cash flows from potential product sales; and the appropriate discount rates for a market participant. Transaction costs and restructuring costs associated with the transaction are expensed as incurred.

The Company records contingent consideration resulting from a business combination at its fair value on the acquisition date. The Company determines the fair value of the contingent consideration based primarily on the (i) timing and probability of success of clinical events or regulatory approvals; (ii) timing and probability of success of meeting clinical and commercial milestones; and (iii) discount rates. The Company's contingent consideration liabilities arose in connection with its acquisition of Kolltan. On a quarterly basis, the Company revalues these obligations and record increases or decreases in their fair value as an adjustment to operating earnings. Changes to contingent consideration obligations can result from adjustments to discount rates, accretion of the discount rates due to the passage of time, changes in the Company's estimates of the likelihood or timing of achieving development or commercial milestones, changes in the probability of certain clinical events or changes in the assumed probability associated with regulatory approval. The assumptions related to determining the value of contingent consideration include a significant amount of judgment, and any changes in the underlying estimates could have a material impact on the amount of contingent consideration expense recorded in any given period.

Intangible Assets

IPR&D assets acquired in a business combination initially are recorded at fair value and accounted for as indefinite-lived intangible assets. These assets are capitalized on the Company's balance sheets until either the project underlying them is completed or the assets become impaired. If a project is completed, the carrying value of the related intangible asset is amortized over the remaining estimated life of the asset beginning in the period in which the project is completed. If a project becomes impaired or is abandoned, the carrying value of the related intangible asset is written down to its fair value and an impairment charge is taken in the period in which the impairment occurs.

IPR&D assets are tested for impairment on an annual basis during the third quarter, or earlier if impairment indicators are present. As part of the annual impairment test of the IPR&D assets as of July 1, 2016, the Company performed a calculation of the fair value of the asset and concluded that the IPR&D assets were not impaired.

Intangible assets acquired in a business combination with a finite life are recorded at fair value and amortized over the greater of economic consumption or on a straight-line basis over their estimated useful life.

Goodwill

The difference between the purchase price and the fair value of assets acquired and liabilities assumed in a business combination is allocated to goodwill. Goodwill is evaluated for impairment on an annual basis during the third quarter, or earlier if impairment indicators are present. The Company has the option to assess qualitative factors to determine if it is more likely than not that goodwill might be impaired and whether it is necessary to perform the two-step goodwill impairment test required under U.S. GAAP. As part of its annual impairment test of the goodwill asset as of July 1, 2016, the Company bypassed the optional qualitative assessment and performed the two-step impairment test. The Company concluded that goodwill was not impaired.

Impairment of Intangible and Long-Lived Assets

The Company evaluates the recoverability of its long-lived assets, including property and equipment, and intangible assets when circumstances indicate that an event of impairment may have occurred. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the assets, the assets are written-down to their estimated fair values.

Revenue Recognition

The Company recognizes revenue when all of the following criteria are met: persuasive evidence of an arrangement exists; delivery has occurred or services have been rendered; the seller's price to the buyer is fixed or determinable; and collectability is reasonably assured.

The Company has entered into and in the future may enter into biopharmaceutical product development agreements with collaborative partners for the research and development of therapeutic drug candidates. The terms of the agreements may include nonrefundable signing and licensing fees, funding for research, development and manufacturing, milestone payments and royalties on any product sales derived from collaborations. These multiple element arrangements are analyzed to determine whether the deliverables can be separated or whether they must be accounted for as a single unit of accounting. In accounting for these transactions, the Company allocates revenue to the various elements based on their relative fair value. The fair value of a revenue generating element can be based on current selling prices offered by the Company or another party for current products or the Company's best estimate of a selling price for future products. Revenue allocated to an individual element is recognized when all other revenue recognition criteria are met for that element.

These collaborative and other agreements may contain milestone payments. Revenues from milestones, if they are considered substantive, are recognized upon successful accomplishment of the milestones. Determining whether a milestone is substantive involves judgment, including an assessment of the Company's involvement in achieving the milestones and whether the amount of the payment is commensurate to the Company's performance. If not considered substantive, milestones are initially deferred and recognized over the period of the remaining performance obligation.

Payments received to fund certain research activities are recognized as revenue in the period in which the research activities are performed. Revenue from contracts and grants is recognized as the services are performed and recorded as effort is expended on the contracted work and billed to the government or the Company's contractual partner. Payments received in advance that are related to future performance are deferred and recognized as revenue when the research projects are performed.

Product royalty revenue consists of payments received from licensees for a portion of sales proceeds from products that utilize the Company's licensed technologies and are recognized when the amount of and basis for such royalty payments are reported to the Company in accurate and appropriate form and in accordance with the related license agreement.

Research and Development Expenses

Research and development costs, including internal and contract research costs, are expensed as incurred. Research and development expenses consist mainly of clinical trial costs, manufacturing of clinical material, toxicology and other preclinical studies, personnel costs, depreciation, license fees and funding of outside contracted research.

Clinical trial expenses include expenses associated with clinical research organizations, or CRO, services. Contract manufacturing expenses include expenses associated with contract manufacturing organizations, or CMO, services. The invoicing from CROs and CMOs for services rendered can lag several months. The Company accrues the cost of services rendered in connection with CRO and CMO activities based on our estimate of costs incurred. The Company maintains regular communication with our CROs and CMOs to assess the reasonableness of its estimates. Differences between actual expenses and estimated expenses recorded have not been material and are adjusted for in the period in which they become known.

Patent Costs

Patent costs are expensed as incurred. Certain patent costs are reimbursed by the Company's product development and licensing partners. Any reimbursed patent costs are recorded as product development and licensing agreement revenues in the Company's financial statements.

Stock-Based Compensation

The Company records stock-based compensation expense for all stock-based awards made to employees and directors based on the estimated fair values of the stock-based awards expected to vest at the grant date and is adjusted, if necessary, to reflect actual forfeitures. Compensation expense for all stock-based awards to employees and directors is recognized using the straight-line method over the term of vesting or performance.

The Company records stock-based compensation expense for stock options granted to non-employees based on the fair value of the stock options which is re-measured over the graded vesting term resulting in periodic adjustments to stock-based compensation expense.

Foreign Currency Translation

Net unrealized gains and losses resulting from foreign currency translation are included in other comprehensive income (loss). At December 31, 2016 and December 31, 2015, accumulated other comprehensive income includes a net unrealized gain related to foreign currency translation of $2.6 million.

Income Taxes

The Company uses the asset and liability method to account for income taxes, including the recognition of deferred tax assets and deferred tax liabilities for the anticipated future tax consequences attributable to differences between financial statement amounts and their respective tax basis. Quarterly, the Company reviews its deferred tax assets for recovery. A valuation allowance is established when the Company believes that it is more likely than not that its deferred tax assets will not be realized. Changes in valuation allowances from period to period are included in the Company's tax provision in the period of change.

The Company records uncertain tax positions in the financial statements only if it is more likely than not that the uncertain tax position will be sustained upon examination by the taxing authorities. The Company records interest and penalties related to uncertain tax positions in income tax expense.

Comprehensive Loss

Comprehensive loss is comprised of net loss and certain changes in stockholders' equity that are excluded from net loss. The Company includes foreign currency translation adjustments and unrealized gains and losses on marketable securities in other comprehensive loss. The statements of operations and comprehensive loss reflect total comprehensive loss for the years ended December 31, 2016, 2015 and 2014.

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:

	Year Ended December 31,
	2016		2015		2014
Stock options		10,218,710		8,110,239		7,015,350
Restricted stock		50,000		19,500		7,000

		10,268,710		8,129,739		7,022,350

Recent Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (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 financial position or results of operations upon adoption.

In May 2014, the FASB issued a new U.S. GAAP accounting standard that creates modifications to various other revenue accounting standards for specialized transactions and industries. The new U.S. GAAP accounting standard requires a company to recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration that the company expects to receive for those goods or services. In August 2015, the FASB deferred the effective date of the new standard from January 1, 2017 to January 1, 2018. The amendment allows for two methods of adoption, a full retrospective method or a modified retrospective approach with the cumulative effect recognized at the date of initial application. The Company will further study the implications of this standard in order to evaluate the expected impact on the financial statements.

In February 2016, the FASB issued 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 will be effective for the Company on January 1, 2019. The Company is currently evaluating the potential impact that this standard may have on the Company's financial statements.

In March 2016, the FASB issued a new U.S. GAAP accounting standard which involves several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. The new standard will be effective for the Company on January 1, 2017. The adoption of this standard is not expected to have a material impact on our financial statements.

In June 2016, the FASB issued a new U.S. GAAP accounting standard which changes the impairment model for most financial assets and certain other instruments. Under the new standard, entities holding financial assets and net investment in leases that are not accounted for at fair value through net income to be presented at the net amount expected to be collected. An allowance for credit losses will be a valuation account that will be deducted from the amortized cost basis of the financial asset to present the net carrying value at the amount expected to be collected on the financial asset. The new standard will be effective for the Company on January 1, 2020. The adoption of this standard is not expected to have a material impact on the Company's financial statements.

In August 2016, the FASB issued a new U.S. GAAP accounting standard which clarifies certain aspects of the statement of cash flows, including the classification of debt prepayment or debt extinguishment costs, settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of corporate-owned life insurance policies, distributions received from equity method investees and beneficial interests in securitization transactions. The new standard also clarifies that an entity should determine each separately identifiable source or use within the cash receipts and cash payments on the basis of the nature of the underlying cash flows. In situations in which cash receipts and payments have aspects of more than one class of cash flows and cannot be separated by source or use, the appropriate classification should depend on the activity that is likely to be the predominant source or use of cash flows for the item. The new standard will be effective for us on January 1, 2018. The Company is currently evaluating the potential impact that this standard may have on the Company's financial statements.

COMPREHENSIVE LOSS

12 Months Ended

Dec. 31, 2016

COMPREHENSIVE LOSS

COMPREHENSIVE LOSS

(3) COMPREHENSIVE LOSS

The changes in accumulated other comprehensive income (loss) by component for the years ended December 31, 2016, 2015 and 2014 are summarized below. No amounts were reclassified out of accumulated other comprehensive income during the years ended December 31, 2016, 2015 and 2014.

	Unrealized Gain (Loss) on Marketable Securities			Foreign Currency Items			Total
	(In thousands)
Balance at December 31, 2013	$	82		$	2,586		$	2,668
Other comprehensive loss before reclassifications		(73	)		(5	)		(78	)
Amounts reclassified from other comprehensive income		—			—			—

Net current-period other comprehensive loss		(73	)		(5	)		(78	)

Balance at December 31, 2014		9			2,581			2,590


Other comprehensive (loss) gain before reclassifications		(298	)		15			(283	)
Amounts reclassified from other comprehensive income		—			—			—

Net current-period other comprehensive (loss) gain		(298	)		15			(283	)

Balance at December 31, 2015	$	(289	)	$	2,596		$	2,307


Other comprehensive gain before reclassifications		234			—			234
Amounts reclassified from other comprehensive income		—			—			—

Net current-period other comprehensive gain		234			—			234

Balance at December 31, 2016	$	(55	)	$	2,596		$	2,541

- Definition

The entire disclosure for comprehensive income, which includes, but is not limited to, 1) the amount of income tax expense or benefit allocated to each component of other comprehensive income, including reclassification adjustments, 2) the reclassification adjustments for each classification of other comprehensive income and 3) the ending accumulated balances for each component of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=66004124&loc=d3e689-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=66004124&loc=SL7669619-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=66004124&loc=d3e640-108580

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=66004124&loc=d3e716-108580

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=66004124&loc=d3e709-108580

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=66004124&loc=d3e637-108580

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=66004124&loc=d3e681-108580

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Reclassification Adjustments
-URI http://asc.fasb.org/extlink&oid=6522872

+ Details

FAIR VALUE MEASUREMENTS

12 Months Ended

Dec. 31, 2016

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS

(4) FAIR VALUE MEASUREMENTS

The following tables set forth the Company's financial assets subject to fair value measurements:

	As of December 31, 2015		Level 1		Level 2		Level 3
	(In thousands)
Assets:
Money market funds and cash equivalents	$	59,831		—	$	59,831		—
Marketable securities	$	217,781		—	$	217,781		—

	$	277,612		—	$	277,612		—

	As of December 31, 2016		Level 1		Level 2		Level 3
	(In thousands)
Assets:
Money market funds and cash equivalents	$	20,445		—	$	20,445		—
Marketable securities	$	147,315		—	$	147,315		—

	$	167,760		—	$	167,760		—


Liabilities:
Kolltan acquisition contingent consideration	$	44,200		—		—	$	44,200

	$	44,200		—		—	$	44,200

Contingent consideration liabilities related to acquisitions are classified as Level 3 within the valuation hierarchy and are valued based on various estimates, including probability of success, discount rates and amount of time until the conditions of the milestone payments are met. In connection with the Kolltan acquisition, we may be required to pay future consideration that is contingent upon the achievement of specified development, regulatory approvals or sales-based milestone events. We determine the fair value of these obligations on the acquisition date using various estimates that are not observable in the market and represent a Level 3 measurement within the fair value hierarchy. The following table represents a roll-forward of our acquisition-related contingent consideration (in thousands):

	December 31, 2016
Balance at beginning of period	$	—
Milestone payments		—
Changes in fair value		—
Kolltan acquisition contingent consideration	$	44,200

Balance at end of period	$	44,200

There have been no transfers of assets or liabilities between the fair value measurement classifications. The Company's financial instruments consist mainly of cash and cash equivalents, marketable securities, short-term accounts receivable and accounts payable. 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. Short-term accounts receivable and accounts payable are reflected in the accompanying financial statements at cost, which approximates fair value due to the short-term nature of these instruments.

- Definition

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

+ References + Details

MARKETABLE SECURITIES

12 Months Ended

Dec. 31, 2016

MARKETABLE SECURITIES

MARKETABLE SECURITIES

(5) MARKETABLE SECURITIES

A summary of marketable securities is shown below:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(In thousands)
December 31, 2016
Marketable securities
U.S. government and municipal obligations
Maturing in one year or less	$	52,754	$	5	$	(12	)	$	52,747
Maturing after one year through three years		296		8		—			304

Total U.S. government and municipal obligations	$	53,050	$	13	$	(12	)	$	53,051

Corporate debt securities
Maturing in one year or less	$	94,320	$	—	$	(56	)	$	94,264
Maturing after one year through three years		—		—		—			—

Total corporate debt securities	$	94,320	$	—	$	(56	)	$	94,264

Total marketable securities	$	147,370	$	13	$	(68	)	$	147,315


December 31, 2015
Marketable securities
U.S. government and municipal obligations
Maturing in one year or less	$	48,871	$	4	$	(20	)	$	48,855
Maturing after one year through three years		15,940		24		(57	)		15,907

Total U.S. government and municipal obligations	$	64,811	$	28	$	(77	)	$	64,762

Corporate debt securities
Maturing in one year or less	$	129,327	$	2	$	(141	)	$	129,188
Maturing after one year through three years		23,932		1		(102	)		23,831

Total corporate debt securities	$	153,259	$	3	$	(243	)	$	153,019

Total marketable securities	$	218,070	$	31	$	(320	)	$	217,781

The marketable securities held by the Company were high investment grade and there were no marketable securities that the Company considered to be other-than-temporarily impaired as of December 31, 2016. Marketable securities include $0.6 million and $1.5 million in accrued interest at December 31, 2016 and December 31, 2015, respectively.

- Definition

The entire disclosure for investments in certain debt and equity securities.

+ References + Details

PROPERTY AND EQUIPMENT, NET

12 Months Ended

Dec. 31, 2016

PROPERTY AND EQUIPMENT, NET

PROPERTY AND EQUIPMENT, NET

(6) PROPERTY AND EQUIPMENT, NET

Property and equipment include the following:

	December 31, 2016			December 31, 2015
	(In thousands)
Laboratory Equipment	$	6,771		$	5,432
Manufacturing Equipment		4,312			4,178
Office Furniture and Equipment		3,677			3,088
Leasehold Improvements		17,115			15,371
Construction in Progress		1,283			451

Total Property and Equipment		33,158			28,520
Less Accumulated Depreciation and Amortization		(19,966	)		(17,059	)

	$	13,192		$	11,461

Depreciation and amortization expense related to property and equipment was $3.1 million, $3.0 million and $2.4 million for the years ended December 31, 2016, 2015 and 2014, respectively.

INTANGIBLE ASSETS AND GOODWILL

12 Months Ended

Dec. 31, 2016

INTANGIBLE ASSETS AND GOODWILL

INTANGIBLE ASSETS AND GOODWILL

(7) INTANGIBLE ASSETS AND GOODWILL

Intangible assets, net of accumulated amortization, and goodwill are as follows:

	December 31, 2016								December 31, 2015
	Estimated Life	Cost		Accumulated Amortization			Net		Cost		Accumulated Amortization			Net
		(In thousands)
Intangible Assets:
IPR&D	Indefinite	$	73,490	$	—		$	73,490	$	11,800	$	—		$	11,800
Amgen Amendment	16 years		14,500		(6,503	)		7,997		14,500		(5,605	)		8,895
Core Technology	11 years		1,296		(1,296	)		—		1,296		(1,197	)		99

Total Intangible Assets		$	89,286	$	(7,799	)	$	81,487	$	27,596	$	(6,802	)	$	20,794

Goodwill	Indefinite	$	90,976	$	—		$	90,976	$	8,965	$	—		$	8,965

The IPR&D intangible asset recorded in connection with the CuraGen acquisition of $11.8 million relates to the development of glembatumumab vedotin. At the date of acquisition and at December 31, 2016, glembatumumab vedotin had not yet reached technological feasibility nor did it have any alternative future use. Glembatumumab vedotin is in a randomized, Phase 2b study for the treatment of triple negative breast cancer and a Phase 2 study for the treatment of metastatic melanoma.

The IPR&D intangible asset recorded in connection with the Kolltan acquisition of $61.7 million relates to the development of the CDX-1058, CDX-3379 and TAM programs. At the date of acquisition and at December 31, 2016, the CDX-1058, CDX-3379 and TAM programs had not yet reached technological feasibility nor did they have any alternative future use. CDX-0158 is a humanized monoclonal antibody currently in a Phase 1 dose escalation study in refractory gastrointestinal stromal tumors and CDX-3379 is a human monoclonal antibody which recently completed a Phase 1b study in patients with solid tumors. The TAM program is a multi-faceted broad antibody discovery effort to generate antibodies that modulate the TAM family of RTKs, comprised of Tyro3, AXL and MerTK, which are expressed on tumor-infiltrating macrophages, dendritic cells and some tumors.

Amortization expense for intangible assets was $1.0 million for the years ended December 31, 2016, 2015 and 2014. The estimated future amortization expense of intangible assets for the years ending December 31, 2017, 2018, 2019, 2020 and 2021 is $0.9 million, $0.9 million, $0.9 million, $0.9 million and $0.9 million, respectively.

- Definition

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.

+ References + Details

ACCRUED EXPENSES

12 Months Ended

Dec. 31, 2016

ACCRUED EXPENSES

ACCRUED EXPENSES

(8) ACCRUED EXPENSES

Accrued expenses include the following:

	December 31, 2016		December 31, 2015
	(In thousands)
Accrued Payroll and Employee Benefits	$	7,132	$	5,601
Accrued Research and Development Contract Costs		17,742		14,548
Accrued Professional Fees		1,146		399
Other Accrued Expenses		2,637		3,768

	$	28,657	$	24,316