License Agreements	3 Months Ended
Mar. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
License Agreements	5. License Agreements Biogen Idec The first amended and restated collaboration agreement with Biogen Idec MA, Inc. (the “Biogen 1st ARCA”) amended and restated the collaboration agreement with Biogen (the “Biogen OCA”), to provide for the discovery, development and commercialization of small molecule BTK inhibitors. Under this agreement, the Company no longer has research obligations, but licenses granted to Biogen with respect to the research collaboration under the Biogen OCA (other than the licenses transferred to Takeda Oncology under the Takeda Agreement) remain in effect. In December 2018, the Company entered into a settlement agreement with Biogen whereas Biogen will no longer be obligated to pay future event-based payments or royalty payments to the Company. In December 2013, the Company entered into a second amended and restated collaboration agreement with Biogen, to provide the Company with an exclusive worldwide license to develop, manufacture and commercialize vecabrutinib, a BTK inhibitor synthesized under the Biogen 1st ARCA, solely for oncology indications. During the third quarter of 2017, the Company made a milestone payment of $2.5 million to Biogen upon the dosing of the first patient in a Phase 1b/2 study to assess the safety and activity of vecabrutinib in patients with advanced B-cell malignancies after two or more prior therapies, including ibrutinib or other covalent BTK inhibitor for those patients with malignancies for which a BTK inhibitor is approved, and including patients with BTK C481 mutations. The payment was recorded in the research and development expenses line item in the consolidated statement of operations. The Company may also be required to make tiered royalty payments based on percentages of net sales of vecabrutinib, if any, in the mid-single-digits. Takeda Oncology In March 2011, Takeda Oncology purchased and exclusively licensed Biogen’s rights to a PDK1 inhibitor program and a pan-Raf inhibitor program which were both originally developed through a collaboration agreement between Sunesis and Biogen. In January 2014, the Company entered into an amended and restated license agreement with Takeda Oncology (the “Amended Takeda Agreement”), to provide the Company with an exclusive worldwide license to develop and commercialize preclinical inhibitors of PDK1. In December 2019, the Company partitioned the Amended Takeda Agreement into two separate agreements: (i) an amended and restated license agreement for PDK (the “PDK Agreement”), and (ii) an amended and restated license agreement for RAF (the “Millennium RAF Agreement”). Pursuant to the PDK Agreement, the Company may in the future be required to make up to $9.1 million in pre-commercialization milestone payments depending on its development of PDK1 inhibitors and tiered royalty payments depending on related product sales, if any, in the mid-single digits. DOT-1 In December 2019, Takeda Oncology assigned the Millennium RAF Agreement to DOT-1, a venture capital-funded biopharmaceutical company. The Company entered into a concurrent license agreement with DOT-1. Pursuant to this agreement, the Company received a $2.0 million upfront payment from DOT-1 to grant DOT-1 a worldwide, exclusive license of TAK-580. The agreement also includes up to $57.0 million in pre-commercialization, event-based milestone payments and royalty payments on future sales of TAK-580. The Company recognized the $2.0 million upfront payment as revenue in 2019 upon execution of the contract. All future event-based milestone and royalty payments are considered fully constrained and therefore, no revenue has been recognized during the three-months ended March 31, 2020. Denovo In December 2019, the Company entered into the Denovo License Agreement, pursuant to which Sunesis licensed vosaroxin intellectual property to Denovo, received an upfront payment of $0.2 million, and is eligible to receive up to $57.0 million in regulatory and commercial milestones payments and double-digit royalty payments on future sales of vosaroxin. The Company recognized as revenue the $0.1 million of the upfront payment in 2019 and the remaining $0.1 million during the three months ended March 31, 2020 when the identified performance obligation was satisfied. All future event-based milestone and royalty payments are considered fully constrained and therefore, no revenue has been recognized on these fully constrained variable consideration during the three-months ended March 31, 2020.

License Agreements

3 Months Ended

Mar. 31, 2020

Goodwill And Intangible Assets Disclosure [Abstract]

5. License Agreements

Biogen Idec

The first amended and restated collaboration agreement with Biogen Idec MA, Inc. (the “Biogen 1st ARCA”) amended and restated the collaboration agreement with Biogen (the “Biogen OCA”), to provide for the discovery, development and commercialization of small molecule BTK inhibitors. Under this agreement, the Company no longer has research obligations, but licenses granted to Biogen with respect to the research collaboration under the Biogen OCA (other than the licenses transferred to Takeda Oncology under the Takeda Agreement) remain in effect. In December 2018, the Company entered into a settlement agreement with Biogen whereas Biogen will no longer be obligated to pay future event-based payments or royalty payments to the Company.

In December 2013, the Company entered into a second amended and restated collaboration agreement with Biogen, to provide the Company with an exclusive worldwide license to develop, manufacture and commercialize vecabrutinib, a BTK inhibitor synthesized under the Biogen 1st ARCA, solely for oncology indications. During the third quarter of 2017, the Company made a milestone payment of $2.5 million to Biogen upon the dosing of the first patient in a Phase 1b/2 study to assess the safety and activity of vecabrutinib in patients with advanced B-cell malignancies after two or more prior therapies, including ibrutinib or other covalent BTK inhibitor for those patients with malignancies for which a BTK inhibitor is approved, and including patients with BTK C481 mutations. The payment was recorded in the research and development expenses line item in the consolidated statement of operations. The Company may also be required to make tiered royalty payments based on percentages of net sales of vecabrutinib, if any, in the mid-single-digits.

Takeda Oncology

In March 2011, Takeda Oncology purchased and exclusively licensed Biogen’s rights to a PDK1 inhibitor program and a pan-Raf inhibitor program which were both originally developed through a collaboration agreement between Sunesis and Biogen. In January 2014, the Company entered into an amended and restated license agreement with Takeda Oncology (the “Amended Takeda Agreement”), to provide the Company with an exclusive worldwide license to develop and commercialize preclinical inhibitors of PDK1. In December 2019, the Company partitioned the Amended Takeda Agreement into two separate agreements: (i) an amended and restated license agreement for PDK (the “PDK Agreement”), and (ii) an amended and restated license agreement for RAF (the “Millennium RAF Agreement”). Pursuant to the PDK Agreement, the Company may in the future be required to make up to $9.1 million in pre-commercialization milestone payments depending on its development of PDK1 inhibitors and tiered royalty payments depending on related product sales, if any, in the mid-single digits.

DOT-1

In December 2019, Takeda Oncology assigned the Millennium RAF Agreement to DOT-1, a venture capital-funded biopharmaceutical company. The Company entered into a concurrent license agreement with DOT-1. Pursuant to this agreement, the Company received a $2.0 million upfront payment from DOT-1 to grant DOT-1 a worldwide, exclusive license of TAK-580. The agreement also includes up to $57.0 million in pre-commercialization, event-based milestone payments and royalty payments on future sales of TAK-580. The Company recognized the $2.0 million upfront payment as revenue in 2019 upon execution of the contract. All future event-based milestone and royalty payments are considered fully constrained and therefore, no revenue has been recognized during the three-months ended March 31, 2020.

Denovo

In December 2019, the Company entered into the Denovo License Agreement, pursuant to which Sunesis licensed vosaroxin intellectual property to Denovo, received an upfront payment of $0.2 million, and is eligible to receive up to $57.0 million in regulatory and commercial milestones payments and double-digit royalty payments on future sales of vosaroxin. The Company recognized as revenue the $0.1 million of the upfront payment in 2019 and the remaining $0.1 million during the three months ended March 31, 2020 when the identified performance obligation was satisfied. All future event-based milestone and royalty payments are considered fully constrained and therefore, no revenue has been recognized on these fully constrained variable consideration during the three-months ended March 31, 2020.