Sierra Oncology, Inc. Appoints Stephen Dilly as Chief Executive Officer, Effective June 1, 2020

Sierra Oncology, Inc. is late stage drug development company. The Company is focused on advancing targeted therapeutics for the treatment of patients with unmet medical needs in hematology and oncology. Momelotinib, the Company's lead drug candidate, is a potent, selective and orally-bioavailable janus kinase one (JAK1), janus kinase two (JAK2) and activin a receptor type one (ACVR1) inhibitor with a differentiated therapeutic profile in myelofibrosis. The Company is also developing a portfolio of deoxyribonucleic acid (DNA) damage response (DDR) assets, consisting of SRA737 and SRA141. SRA737 is a potent, selective, orally bioavailable small molecule inhibitor of checkpoint kinase 1 (Chk1), a key regulator of cell cycle progression and the DDR network. SRA141 is a potent, selective, orally bioavailable small molecule inhibitor of Cell division cycle 7 kinase (Cdc7).