License Agreements	3 Months Ended
Mar. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
License Agreements	6. License Agreements Biogen In December 2013, the Company entered into a second amended and restated collaboration agreement with Biogen Idec MA, Inc. (the “Biogen 2nd ARCA”), to provide the Company with an exclusive worldwide license to develop, manufacture and commercialize SNS-062, a BTK inhibitor synthesized under the first amended and restated collaboration agreement with Biogen (the “Biogen 1st ARCA”), solely for oncology indications. The Company may be required to make a $2.5 million milestone payment depending on its development of SNS-062 and royalty payments depending on related product sales of SNS-062. All other of Sunesis’ rights and obligations contained in the Biogen 1st ARCA remain unchanged, except that potential future royalty payments to Sunesis were reduced to equal those amounts due to Biogen for potential future sales of SNS-062. Takeda In March 2011, Takeda Pharmaceuticals, Inc., a wholly-owned subsidiary of Takeda Pharmaceutical Company Limited (“Takeda”) 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 (the “Amended Takeda Agreement”), to provide the Company with an exclusive worldwide license to develop and commercialize preclinical inhibitors of PDK1. In connection with the execution of the Amended Takeda Agreement, the Company paid an upfront fee and may be required to make up to $9.2 million in pre-commercialization milestone payments depending on its development of PDK1 inhibitors and royalty payments depending on related product sales, if any. With respect to the pan-Raf inhibitor program, the Company may in the future receive up to $57.5 million in pre-commercialization event-based payments related to the development by Takeda of the first two indications for each of the licensed products directed against the Raf target and royalty payments depending on related product sales. Under this program, Takeda is currently conducting Phase 1 clinical studies of an oral investigative drug, TAK-580 (formerly MLN2480).

6. License Agreements

Biogen

In December 2013, the Company entered into a second amended and restated collaboration agreement with Biogen Idec MA, Inc. (the “Biogen 2nd ARCA”), to provide the Company with an exclusive worldwide license to develop, manufacture and commercialize SNS-062, a BTK inhibitor synthesized under the first amended and restated collaboration agreement with Biogen (the “Biogen 1st ARCA”), solely for oncology indications. The Company may be required to make a $2.5 million milestone payment depending on its development of SNS-062 and royalty payments depending on related product sales of SNS-062. All other of Sunesis’ rights and obligations contained in the Biogen 1st ARCA remain unchanged, except that potential future royalty payments to Sunesis were reduced to equal those amounts due to Biogen for potential future sales of SNS-062.

Takeda

In March 2011, Takeda Pharmaceuticals, Inc., a wholly-owned subsidiary of Takeda Pharmaceutical Company Limited (“Takeda”) 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 (the “Amended Takeda Agreement”), to provide the Company with an exclusive worldwide license to develop and commercialize preclinical inhibitors of PDK1. In connection with the execution of the Amended Takeda Agreement, the Company paid an upfront fee and may be required to make up to $9.2 million in pre-commercialization milestone payments depending on its development of PDK1 inhibitors and royalty payments depending on related product sales, if any.

With respect to the pan-Raf inhibitor program, the Company may in the future receive up to $57.5 million in pre-commercialization event-based payments related to the development by Takeda of the first two indications for each of the licensed products directed against the Raf target and royalty payments depending on related product sales. Under this program, Takeda is currently conducting Phase 1 clinical studies of an oral investigative drug, TAK-580 (formerly MLN2480).