Subsequent Event	3 Months Ended
Mar. 31, 2019
Subsequent Events [Abstract]
Subsequent Event	Note 9. Subsequent Event On April 30, 2019, the Company and Strata Oncology, Inc. (Strata) entered into a Co-Development and Collaboration Agreement (the Co-Development and Collaboration Agreement) to pursue a clinical development collaboration utilizing Strata’s precision drug development platform and proprietary biomarkers to evaluate AB122, the Company’s clinical-stage anti-PD-1 antibody, in patients in a tumor-agnostic fashion. Under the terms of the Co-Development and Collaboration Agreement, the parties will share development costs for the clinical collaboration. Strata is eligible to receive $2.5 million upon the achievement of a development milestone, as well as regulatory and commercial milestones and royalties on U.S. net sales of AB122 in the biomarker-identified indication. As further consideration in connection with the Co-Development and Collaboration Agreement, the Company issued to Strata 1,257,651 restricted shares of its common stock, which are subject to vesting based upon the achievement of regulatory milestones within certain timelines.

Subsequent Event

3 Months Ended

Mar. 31, 2019

Note 9. Subsequent Event

On April 30, 2019, the Company and Strata Oncology, Inc. (Strata) entered into a Co-Development and Collaboration Agreement (the Co-Development and Collaboration Agreement) to pursue a clinical development collaboration utilizing Strata’s precision drug development platform and proprietary biomarkers to evaluate AB122, the Company’s clinical-stage anti-PD-1 antibody, in patients in a tumor-agnostic fashion.

Under the terms of the Co-Development and Collaboration Agreement, the parties will share development costs for the clinical collaboration. Strata is eligible to receive $2.5 million upon the achievement of a development milestone, as well as regulatory and commercial milestones and royalties on U.S. net sales of AB122 in the biomarker-identified indication. As further consideration in connection with the Co-Development and Collaboration Agreement, the Company issued to Strata 1,257,651 restricted shares of its common stock, which are subject to vesting based upon the achievement of regulatory milestones within certain timelines.