Collaboration and Other Agreements	3 Months Ended
Collaboration and Other Agreements	Mar. 31, 2021
Collaboration and License Agreements [Abstract]
Collaboration and Other Agreements	Collaboration and Other Agreements Incyte Corporation In 2017, the Company entered into an exclusive global collaboration and license agreement with Incyte Corporation (Incyte) for retifanlimab (formerly known as MGA012 and INCMGA0012), an investigational monoclonal antibody that inhibits programmed cell death protein 1 (PD-1) (Incyte License Agreement). Incyte has obtained exclusive worldwide rights for the development and commercialization of retifanlimab in all indications, while the Company retains the right to develop its pipeline assets in combination with retifanlimab. Under the terms of the Incyte License Agreement, Incyte paid the Company an upfront payment of $150.0 million in 2017. In January 2021, Incyte announced that the FDA had accepted for Priority Review its Biologics License Application for retifanlimab as a potential treatment for adult patients with locally advanced or metastatic squamous cell carcinoma of the anal canal. The PDUFA target action date for retifanlimab is July 25, 2021. Under the terms of the Incyte License Agreement, Incyte will lead global development of retifanlimab. Assuming successful development and commercialization of retifanlimab by Incyte, the Company could receive up to approximately $420.0 million in development and regulatory milestones and up to $330.0 million in commercial milestones. From the inception of the Incyte License Agreement through March 31, 2021, the Company has recognized $65.0 million in development milestones under the Incyte License Agreement. If retifanlimab is approved and commercialized, the Company would be eligible to receive tiered royalties of 15% to 24% on any global net sales. The Company retains the right to develop its pipeline assets in combination with retifanlimab, with Incyte commercializing retifanlimab and the Company commercializing its asset(s), if any such potential combinations are approved. In addition, the Company retains the right to manufacture a portion of both companies' global commercial supply needs of retifanlimab, subject to the separate commercial supply agreement. The Company evaluated the Incyte License Agreement under ASC 606 and identified the following two performance obligations under the agreement: (i) the license of retifanlimab and (ii) the performance of certain clinical activities through a brief technology transfer period. The Company determined that the license and clinical activities are separate performance obligations because they are capable of being distinct, and are distinct in the context of the contract. The license has standalone functionality as it is sublicensable, Incyte has significant capabilities in performing clinical trials, and Incyte is capable of performing these activities without the Company's involvement; the Company performed the activities during the transfer period as a matter of convenience. The Company determined that the transaction price of the Incyte License Agreement at inception was $154.0 million, consisting of the consideration to which the Company was entitled in exchange for the license and an estimate of the consideration for clinical activities to be performed. The transaction price was allocated to each performance obligation based on their relative standalone selling price. The standalone selling price of the license was determined using the adjusted market assessment approach considering similar collaboration and license agreements. The standalone selling price for the agreed-upon clinical activities to be performed was determined using the expected cost approach based on similar arrangements the Company has with other parties. The potential development and regulatory milestone payments are fully constrained until the Company concludes that achievement of the milestone is probable and that recognition of revenue related to the milestone will not result in a significant reversal in amounts recognized in future periods, and as such have been excluded from the transaction price. Any consideration related to sales-based milestones and royalties will be recognized when the related sales occur, as they were determined to relate predominantly to the license granted to Incyte and, therefore, have also been excluded from the transaction price. The Company re-assesses the transaction price in each reporting period and when events whose outcomes are resolved or other changes in circumstances occur. From 2018 through March 31, 2021, it became probable that a significant reversal of cumulative revenue would not occur for development milestones totaling $65.0 million related to clinical and regulatory activities related to the further advancement of retifanlimab, including Incyte’s initiation of a Phase 3 clinical trial. Therefore the associated consideration was added to the estimated transaction price. The Company recognized the $150.0 million allocated to the license when it satisfied its performance obligation and transferred the license to Incyte in 2017. The $4.0 million allocated to the clinical activities was recognized ratably as services were performed over a period spanning 2017 and 2018. During the three months ended March 31, 2021, it became probable that a significant reversal of cumulative revenue would not occur for another $10.0 million milestone related to development progress of retifanlimab outside the U.S., therefore the associated consideration was added to the estimated transaction price and was recognized as revenue. No revenue was recognized under the Incyte License Agreement during the three months ended March 31, 2020. The Company also has an agreement with Incyte, which was entered into in 2018, under which the Company is to perform development and manufacturing services for Incyte’s clinical needs of retifanlimab (Incyte Clinical Supply Agreement). The Company evaluated the agreement under ASC 606 and identified one performance obligation under the agreement: to perform services related to the development and manufacturing of the clinical supply of retifanlimab. The transaction price is based on the costs incurred to develop and manufacture drug product and drug substance, and is recognized over time as the services are provided, as the performance by the Company does not create an asset with an alternative use and the Company has an enforceable right to payment for the performance completed to date. The transaction price will be recognized using the input method reflecting the costs incurred (including resources consumed and labor hours expended) related to the manufacturing services. During the three months ended March 31, 2021 and 2020, the Company recognized revenue of $0.1 million and $5.9 million, respectively, for services performed under the Incyte Clinical Supply Agreement. In October 2020, the Company entered into an agreement with Incyte pursuant to which the Company is entitled to manufacture a portion of the global commercial supply needs for retifanlimab (Incyte Commercial Supply Agreement). Unless terminated earlier, the term of the Incyte Commercial Supply Agreement will expire upon the expiration of Incyte’s obligation to pay royalties under the Incyte License Agreement. The Company evaluated this agreement under ASC 606 and identified one performance obligation under the agreement: to perform services related to manufacturing the commercial supply of retifanlimab. The transaction price is based on a fixed price per batch of bulk drug substance to be manufactured and is recognized over time as the services are provided, as the performance by the Company does not create an asset with an alternative use and the Company has an enforceable right to payment for the performance completed to date. The transaction price will be recognized using the input method reflecting the costs incurred (including resources consumed and labor hours expended) related to the manufacturing services. During the three months ended March 31, 2021, the Company recognized revenue of $3.1 million for services performed under the Incyte Commercial Supply Agreement. Zai Lab Limited In 2018, the Company entered into a collaboration and license agreement with Zai Lab Limited (Zai Lab) under which Zai Lab obtained regional development and commercialization rights in mainland China, Hong Kong, Macau and Taiwan (Zai Lab’s territory) for (i) margetuximab, an immune-optimized anti-HER2 monoclonal antibody, (ii) tebotelimab (formerly known as MGD013), a bispecific DART molecule designed to provide coordinate blockade of PD-1 and LAG-3 for the potential treatment of a range of solid tumors and hematological malignancies, and (iii) an undisclosed multi-specific TRIDENT molecule in preclinical development (Zai Lab Agreement). Zai Lab will lead clinical development of these molecules in its territory. Under the terms of the Zai Lab Agreement, Zai Lab paid the Company an upfront payment of $25.0 million ($22.5 million after netting value-added tax withholdings of $2.5 million). Assuming successful development and commercialization of margetuximab, tebotelimab and the TRIDENT molecule, the Company could receive up to $140.0 million in development and regulatory milestones, $4.0 million of which ($3.6 million after netting value-added tax withholdings of $0.4 million) was earned during the three months ended March 31, 2020. In addition, Zai Lab would pay the Company tiered royalties at percentage rates of mid-teens to 20% for net sales of margetuximab in Zai Lab’s territory, mid-teens for net sales of tebotelimab in Zai Lab’s territory and 10% for net sales of the TRIDENT molecule in Zai Lab’s territory, which may be subject to adjustment in specified circumstances. The Company evaluated the Zai Lab Agreement under the provisions of ASC 606 and identified the following material promises under the arrangement for each of the two product candidates, margetuximab and tebotelimab: (i) an exclusive license to develop and commercialize the product candidate in Zai Lab’s territory and (ii) certain research and development activities. The Company determined that each license and the related research and development activities were not distinct from one another, as the license has limited value without the performance of the research and development activities. As such, the Company determined that these promises should be combined into a single performance obligation for each product candidate. Activities related to margetuximab and tebotelimab are separate performance obligations from each other because they are capable of being distinct, and are distinct in the context of the contract. The Company evaluated the promises related to the TRIDENT molecule and determined they were immaterial in context of the contract, therefore there is no performance obligation related to that molecule. The Company determined that the net $22.5 million upfront payment from Zai Lab constituted the entirety of the consideration to be included in the transaction price as of the outset of the arrangement, and the transaction price was allocated to the two performance obligations based on their relative standalone selling price. The standalone selling price of the performance obligations was determined using the adjusted market assessment approach considering similar collaboration and license agreements. The potential development and regulatory milestone payments are fully constrained until the Company concludes that achievement of the milestone is probable, and that recognition of revenue related to the milestone will not result in a significant reversal in amounts recognized in future periods, and as such have been excluded from the transaction price. Any consideration related to royalties will be recognized if and when the related sales occur, as they were determined to relate predominantly to the license granted to Zai Lab and, therefore, have also been excluded from the transaction price. The Company re-assesses the transaction price in each reporting period and when events whose outcomes are resolved or other changes in circumstances occur. Due to the relatively short-term nature of the recognition period, the revenue associated with the tebotelimab performance obligation was recognized on a straight-line basis as the Company performed research and development activities under the agreement. The fixed consideration related to the margetuximab performance obligation was also recognized on a straight-line basis as the Company performed research and development activities under the agreement due to the short-term nature of the recognition period. Straight-line recognition is materially consistent with the pattern of performance of the research and development activities of each product candidate. The variable consideration related to the margetuximab performance obligation was recognized upon certain regulatory achievements during 2020. The Company recognized revenue of $3.6 million during the three months ended March 31, 2020 under the Zai Lab Agreement. There was no revenue deferred under this agreement as of March 31, 2021 or December 31, 2020. During 2019, the Company entered into two agreements under which the Company is to perform manufacturing services for Zai Lab’s clinical needs of margetuximab and tebotelimab (Zai Lab Clinical Supply Agreements). The Company evaluated the agreements under ASC 606 and determined that they should be accounted for as a single contract and identified two performance obligations within that contract: to perform services related to manufacturing the clinical supply of each of margetuximab and tebotelimab. The transaction price is based on the costs incurred to manufacture drug product and drug substance, and is recognized over time as the services are provided, as the performance by the Company does not create an asset with an alternative use and the Company has an enforceable right to payment for the performance completed to date. During the three months ended March 31, 2021 and 2020, the Company recognized revenue of $1.1 million and $1.0 million, respectively, related to the Zai Lab Clinical Supply Agreements. Janssen Biotech, Inc. In December 2020, the Company entered into a research collaboration and license agreement with Janssen Biotech, Inc. (Janssen) to develop a novel DART molecule (Janssen Agreement). The research collaboration will incorporate the Company’s proprietary DART platform to enable simultaneous targeting of two undisclosed targets in a therapeutic area outside oncology. Under the terms of the Janssen Agreement, Janssen paid the Company an upfront payment of $20.0 million and will be responsible for funding all research and development expenses. The Company will also be eligible to receive up to $312.0 million in potential milestone payments and tiered royalties of up to 10% on worldwide product sales. Subject to the terms of this agreement, the Company granted Janssen an exclusive, royalty-bearing license to develop, manufacture and commercialize the preclinical bispecific molecule and the Company will perform certain research and development activities during a specified research term. The Company evaluated the Janssen Agreement under the provisions of ASC 606 and identified the following material promises under the arrangement: (i) a license to develop the preclinical bispecific molecule and (ii) performing certain research and development activities during the research term. The Company determined that the license and research and development activities are separate performance obligations because they are capable of being distinct, and are distinct in the context of the contract. The license has standalone functionality as Janssen could benefit from the license on its own without the Company’s involvement during the research term. The Company determined that the transaction price of the Janssen Agreement at inception was $22.2 million, consisting of the consideration to which the Company was entitled in exchange for the license and an estimate of the consideration for research and development activities to be performed. The transaction price was allocated to each performance obligation based on their relative standalone selling price. The standalone selling price of the license was determined using the adjusted market assessment approach considering similar collaboration and license agreements as well as current market conditions. The standalone selling price for agreed-upon research and development activities to be performed was determined using the expected cost approach based on similar arrangements the Company has with other parties. This variable consideration is fully constrained until the Company begins its work under the performance obligation. The potential milestone payments are fully constrained until the Company concludes that achievement of the milestone is probable and that recognition of revenue related to the milestone will not result in a significant reversal in amounts recognized in future periods, and as such have been excluded from the transaction price. Any consideration related to sales-based milestones and royalties will be recognized when the related sales occur, as they were determined to relate predominantly to the license granted to Janssen and, therefore, have also been excluded from the transaction price. The Company re-assesses the transaction price in each reporting period and when events whose outcomes are resolved or other changes in circumstances occur. The Company recognized the $20.0 million allocated to the license when it satisfied its performance obligation and transferred the license to Janssen in December 2020. The $2.2 million allocated to the research and development activities is being recognized over the Company’s involvement in the research term, which is estimated to be less than two years. During the three months ended March 31, 2021, the Company recognized revenue of $0.3 million related to performance of the research and development activities. I-Mab Biopharma In 2019, the Company entered into a collaboration and license agreement with I-Mab Biopharma (I-Mab) to develop and commercialize enoblituzumab, an immune-optimized, anti-B7-H3 monoclonal antibody that incorporates the Company's proprietary Fc Optimization technology platform (I-Mab Agreement). I-Mab obtained regional development and commercialization rights in mainland China, Hong Kong, Macau and Taiwan (I-Mab's territory), will lead clinical development of enoblituzumab in its territories, and will participate in global studies conducted by the Company. Under the terms of the I-Mab Agreement, I-Mab paid the Company an upfront payment of $15.0 million. Assuming successful development and commercialization of enoblituzumab, the Company could receive up to $135.0 million in development and regulatory milestones. In addition, I-Mab would pay the Company tiered royalties ranging from mid-teens to 20% on annual net sales in I-Mab's territory. The Company evaluated the I-Mab Agreement under the provisions of ASC 606 and identified the following material promises under the arrangement: (i) an exclusive license to develop and commercialize enoblituzumab in I-Mab’s territories, (ii) perform certain research and development activities and (iii) conduct a chronic toxicology study. The Company determined that the license and the related research and development activities were not distinct from one another, as the license has limited value without the performance of the research and development activities. As such, the Company determined that the license and related research and development activities should be combined into a single performance obligation. The Company determined that the $15.0 million upfront payment from I-Mab constituted the entirety of the consideration to be included in the transaction price as of the outset of the arrangement for the license and related research and development activities. The Company has also determined that the chronic toxicology study is distinct from the other promises and has estimated the variable consideration of that performance obligation to be approximately $1.0 million. I-Mab will pay the Company for the cost of this study as the costs are incurred and I-Mab will be entitled to a one-time credit of eighty percent of the total amount of such costs against a future milestone, at which point the Company will reassess the transaction price for that milestone. The potential development and regulatory milestone payments are fully constrained until the Company concludes that achievement of the milestone is probable, and that recognition of revenue related to the milestone will not result in a significant reversal in amounts recognized in future periods, and as such have been excluded from the transaction price. Any consideration related to royalties will be recognized if and when the related sales occur, as they were determined to relate predominantly to the license granted to I-Mab and, therefore, have also been excluded from the transaction price. The Company re-assesses the transaction price in each reporting period and when events whose outcomes are resolved or other changes in circumstances occur. Revenue under the I-Mab Agreement is being recognized using a cost-based input method according to costs incurred to date compared to estimated total costs. The transfer of control occurs over this time period and, in management’s judgment, is the best measure of progress towards satisfying the performance obligations. During the three months ended March 31, 2021 and 2020, the Company recognized revenue of $0.6 million and $1.1 million, respectively, under the I-Mab Agreement. At March 31, 2021, $10.8 million of revenue was deferred under this agreement, $3.5 million of which was current and $7.3 million of which was non-current. At December 31, 2020, $11.4 million of revenue was deferred under this agreement, $4.5 million of which was current and $6.9 million of which was non-current. NIAID Contract The Company entered into a contract with National Institute of Allergy and Infectious Diseases (NIAID), effective as of September 15, 2015, to perform product development and to advance up to two DART molecules, including MGD014 (NIAID Contract). Under the NIAID Contract, the Company will develop these product candidates for Phase 1/2 clinical trials as therapeutic agents, in combination with latency reversing treatments, to deplete cells infected with human immunodeficiency virus (HIV) infection. NIAID does not receive goods or services from the Company under this contract, therefore the Company does not consider NIAID to be a customer and concluded this contract is outside the scope of ASC 606. The NIAID Contract includes a base period of up to $7.5 million to support development of MGD014 through Investigational New Drug application submission with the FDA, as well as up to $17.0 million in additional development funding via NIAID options. Should NIAID fully exercise such options, the Company could receive total payments of up to $24.5 million. The total potential period of performance under the award is from September 15, 2015 through December 31, 2024. In 2017, NIAID exercised the first option in the amount of up to $10.8 million to fund the commencement of the MGD014 clinical trial and development of the second DART molecule. During the three months ended March 31, 2021 and 2020, the Company recognized revenue under the NIAID Contract of $0.8 million and $0.7 million, respectively.