Sierra Oncology, Inc. researches, develops, and commercializes therapies for the treatment of patients with hematology and oncology needs. Its lead drug candidate, momelotinib, is a selective and orally-bioavailable JAK1, JAK2, and ACVR1 inhibitor that has been investigated in two completed Phase 3 trials for the treatment of myelofibrosis. The company is also advancing SRA737, an orally bioavailable small molecule inhibitor Checkpoint kinase 1 is being investigated in two Phase 1/2 clinical trials; and SRA141, an orally bioavailable small molecule inhibitor of cell division cycle 7 kinase. The company was formerly known as ProNAi Therapeutics, Inc. and changed its name to Sierra Oncology, Inc. in January 2017. Sierra Oncology, Inc. was founded in 2003 and is headquartered in Vancouver, Canada.