Revenue	12 Months Ended
Dec. 31, 2019
Revenue
Revenue	(13) Revenue On January 1, 2018, the Company adopted a new revenue accounting standard, “Revenue from Contracts with Customers” (ASC 606). Upon adoption using the modified retrospective application, the Company recognized a $1.3 million decrease to accumulated deficit, a $0.8 million decrease in deferred revenue and $0.5 million increase in accounts receivable due to the cumulative impact of adopting ASC 606. This impact was driven by the acceleration of revenue using a percentage-of-completion method of accounting under ASC 606 for an open contract that had previously been accounted for using the Contingency Adjusted Performance Model (“CAPM”) under previous guidance. Results for reporting periods beginning after January 1, 2018 are presented under ASC 606 while prior period amounts were not adjusted and continue to be reported in accordance with historic accounting under previous guidance. There was not a material impact to revenues as a result of applying ASC 606 for the year ended December 31, 2018, and there have not been significant changes to the Company’s business processes, systems or internal controls as a result of adopting the new standard. Revenue recognition remained largely unchanged under the new standard. Contract Assets and Liabilities At December 31, 2019 and 2018, the Company's right to consideration under all contracts was considered unconditional, and as such, there were no recorded contract assets. At December 31, 2019 and 2018, the Company had $0.3 million and $1.6 million in contract liabilities recorded, respectively. Revenue recognized from contract liabilities as of December 31, 2018 during the year ended December 31, 2019 was $1.4 million. Product Development and Licensing Revenue The Company entered into a clinical collaboration agreement with BMS in 2014 to evaluate the safety, tolerability and preliminary efficacy of varlilumab and Opdivo(R), 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 performance obligations under the collaboration agreement consist of intellectual property licenses and the performance of research and development services. The Company determined that the performance obligations were not separately identifiable and were not distinct (and did not have standalone value) due to the specialized nature of the services to be provided, the dependent relationship between the performance obligations and the Company's proprietary technology that makes them uniquely qualified to perform the R&D services. Therefore, the Company concluded that the collaboration agreement has a single identified or combined performance obligation. As of December 31, 2019, deferred revenue related to the Company's remaining performance obligation under this arrangement was $0.0 million. The Company recorded $0.2 million, $3.3 million and $2.8 million in revenue related to this agreement during the years ended December 31, 2019, 2018 and 2017, 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 $2.6 million, $3.2 million and $2.2 million in revenue for labor hours and direct costs incurred under these agreements during the years ended December 31, 2019, 2018 and 2017, respectively. The Company has entered into fixed-fee manufacturing and research and development arrangements with both the International AIDS Vaccine Initiative (IAVI) and Frontier Biotechnologies, Inc (Frontier). The Company recognized $0.3 million, $3.0 million and $6.6 million in revenue under these agreements during the years ended December 31, 2019, 2018 and 2017, respectively.

(13) Revenue

On January 1, 2018, the Company adopted a new revenue accounting standard, “Revenue from Contracts with Customers” (ASC 606). Upon adoption using the modified retrospective application, the Company recognized a $1.3 million decrease to accumulated deficit, a $0.8 million decrease in deferred revenue and $0.5 million increase in accounts receivable due to the cumulative impact of adopting ASC 606. This impact was driven by the acceleration of revenue using a percentage-of-completion method of accounting under ASC 606 for an open contract that had previously been accounted for using the Contingency Adjusted Performance Model (“CAPM”) under previous guidance.

Results for reporting periods beginning after January 1, 2018 are presented under ASC 606 while prior period amounts were not adjusted and continue to be reported in accordance with historic accounting under previous guidance. There was not a material impact to revenues as a result of applying ASC 606 for the year ended December 31, 2018, and there have not been significant changes to the Company’s business processes, systems or internal controls as a result of adopting the new standard. Revenue recognition remained largely unchanged under the new standard.

Contract Assets and Liabilities

At December 31, 2019 and 2018, the Company's right to consideration under all contracts was considered unconditional, and as such, there were no recorded contract assets. At December 31, 2019 and 2018, the Company had $0.3 million and $1.6 million in contract liabilities recorded, respectively. Revenue recognized from contract liabilities as of December 31, 2018 during the year ended December 31, 2019 was $1.4 million.

Product Development and Licensing Revenue

The Company entered into a clinical collaboration agreement with BMS in 2014 to evaluate the safety, tolerability and preliminary efficacy of varlilumab and Opdivo(R), 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 performance obligations under the collaboration agreement consist of intellectual property licenses and the performance of research and development services. The Company determined that the performance obligations were not separately identifiable and were not distinct (and did not have standalone value) due to the specialized nature of the services to be provided, the dependent relationship between the performance obligations and the Company's proprietary technology that makes them uniquely qualified to perform the R&D services. Therefore, the Company concluded that the collaboration agreement has a single identified or combined performance obligation. As of December 31, 2019, deferred revenue related to the Company's remaining performance obligation under this arrangement was $0.0 million. The Company recorded $0.2 million, $3.3 million and $2.8 million in revenue related to this agreement during the years ended December 31, 2019, 2018 and 2017, 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 $2.6 million, $3.2 million and $2.2 million in revenue for labor hours and direct costs incurred under these agreements during the years ended December 31, 2019, 2018 and 2017, respectively.

The Company has entered into fixed-fee manufacturing and research and development arrangements with both the International AIDS Vaccine Initiative (IAVI) and Frontier Biotechnologies, Inc (Frontier). The Company recognized $0.3 million, $3.0 million and $6.6 million in revenue under these agreements during the years ended December 31, 2019, 2018 and 2017, respectively.