Sierra's lead drug candidate, momelotinib, is a potent, selective and orally-bioavailable JAK1, JAK2 & ACVR1 inhibitor with a differentiated therapeutic profile in myelofibrosis encompassing a range of meaningful anemia benefits, including eliminating or reducing the need for frequent blood transfusions, as well as achieving substantive spleen and constitutional symptom control.

Sierra is also advancing SRA737 and SRA141. SRA737 is a potent, highly selective, orally bioavailable small molecule inhibitor of Checkpoint kinase 1, a key regulator of cell cycle progression and the DNA Damage Response. SRA737 is currently being investigated in two Phase I/II clinical trials primarily focused on patients with ovarian cancer: SRA737-01, a monotherapy study, and SRA737-02, a drug combination study evaluating SRA737 potentiated by low dose gemcitabine.

In August 2018, Sierra  acquired rights to the myelofibrosis drug momelotinib from US biotech giant Gilead Sciences.