License Agreements	3 Months Ended
Mar. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
License Agreements	5. License Agreements Biogen In December 2013, the Company entered into a second amended and restated collaboration agreement with Biogen Inc. (the “Biogen 2nd ARCA”), to provide the Company with an exclusive worldwide license to develop, manufacture and commercialize vecabrutinib, a BTK inhibitor synthesized under an earlier collaboration with Biogen, solely for oncology indications. During the third quarter of 2017, the Company made the final milestone payment of $2.5 million to Biogen upon the dosing of the first patient in the Phase 1b/2 study to assess the safety and activity of vecabrutinib in patients with advanced B-cell malignancies. 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 In March 2011, Takeda Oncology, a wholly-owned subsidiary of Takeda Pharmaceutical Company Limited (“Takeda”) purchased exclusive rights to the PDK1 inhibitor and pan-Raf inhibitor programs which were both originally developed through the Company’s collaboration with 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 tiered royalty payments based on percentages of net sales, if any, beginning in the mid-single-digits and not to exceed the low-teens. With respect to the pan-Raf inhibitor program, TAK-580 (formerly MLN2480), 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. TAK-580 is currently being studied in a Phase 1b/2 clinical study for children with low-grade gliomas. As of March 31, 2019, all future event-based payments and royalty payments are considered fully constrained variable considerations and therefore, no contract assets have been recorded and no revenue have been recognized.

License Agreements

3 Months Ended

Mar. 31, 2019

Goodwill And Intangible Assets Disclosure [Abstract]

5. License Agreements

Biogen

In December 2013, the Company entered into a second amended and restated collaboration agreement with Biogen Inc. (the “Biogen 2nd ARCA”), to provide the Company with an exclusive worldwide license to develop, manufacture and commercialize vecabrutinib, a BTK inhibitor synthesized under an earlier collaboration with Biogen, solely for oncology indications. During the third quarter of 2017, the Company made the final milestone payment of $2.5 million to Biogen upon the dosing of the first patient in the Phase 1b/2 study to assess the safety and activity of vecabrutinib in patients with advanced B-cell malignancies. 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

In March 2011, Takeda Oncology, a wholly-owned subsidiary of Takeda Pharmaceutical Company Limited (“Takeda”) purchased exclusive rights to the PDK1 inhibitor and pan-Raf inhibitor programs which were both originally developed through the Company’s collaboration with 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 tiered royalty payments based on percentages of net sales, if any, beginning in the mid-single-digits and not to exceed the low-teens.

With respect to the pan-Raf inhibitor program, TAK-580 (formerly MLN2480), 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. TAK-580 is currently being studied in a Phase 1b/2 clinical study for children with low-grade gliomas. As of March 31, 2019, all future event-based payments and royalty payments are considered fully constrained variable considerations and therefore, no contract assets have been recorded and no revenue have been recognized.