Sierra Oncology Signs Exclusive Global In-Licensing Agreement with AstraZeneca for
Novel BET Inhibitor to Expand Myelofibrosis Pipeline
—Combination study to build upon momelotinib’s differentiated potential as a cornerstone
myelofibrosis therapy-—
SAN MATEO, CA, August 4, 2021 – Sierra Oncology, Inc. (NASDAQ: SRRA), a late-stage biopharmaceutical company on a mission to deliver targeted therapies that treat rare forms of cancer, today announced it has acquired an exclusive global license from AstraZeneca (LSE/STO/NASDAQ: AZN) for AZD5153, a potent and selective BRD4 BET inhibitor with a novel bivalent binding mode. Sierra plans to initiate a Phase 2 study examining momelotinib in combination with AZD5153 in myelofibrosis patients in the first half of 2022.
“This global in-licensing deal is of two-fold importance to Sierra’s long-term strategy. First, it brings another novel compound into the Sierra development pipeline, expanding our opportunity to deliver transformative therapies for patients with rare cancers. Second, it may allow us to enhance and extend our ability to treat myelofibrosis patients, building on momelotinib’s potential as a cornerstone therapy,” said Stephen Dilly, MBBS, PhD, President and Chief Executive Officer at Sierra Oncology.
Inhibitors of the Bromodomain and Extra-terminal Domain (BET protein family consisting of BRD2, BRD3, BRD4 and BRDT) can modify a range of pathological cellular processes, including the initiation and continuation of transcription and cell cycle control. BET inhibition can lead to decreased inflammatory cytokine release, anti-fibrotic activity and reduced mutant cell proliferation, all of which are indicative of disease-modifying effects. Several BET inhibitors are under clinical investigation in multiple solid tumor and hematologic indications, including myelofibrosis.
AZD5153 is a selective BRD4 inhibitor with a novel bivalent binding mode that inhibits both protein bromodomains, resulting in improved potency. Unlike currently available JAK inhibitors, momelotinib is not myelosuppressive, therefore the combination of momelotinib and AZD5153 may provide an efficacy and safety advantage over other JAK inhibitor plus BET inhibitor combinations and allow for prolonged dose intensity and treatment duration. This trial will be designed to provide preliminary proof of concept for a future confirmatory study and support potential additional studies of momelotinib with other novel agents in development for myelofibrosis. Trial initiation is anticipated to begin in the first half of 2022.
Mark Kowalski, MD, PhD, Chief, Early Research and Development at Sierra added, “The combination of JAK inhibition and BET inhibition has been identified as a promising emergent approach for the treatment of myelofibrosis. However, currently available JAK inhibitors are
myelosuppressive, leaving a critical unmet need for patients with anemia or those at risk of developing treatment-emergent anemia. Given momelotinib’s unique mechanism as an inhibitor of ACVR1 / ALK2 in addition to JAK1 and JAK2, we are excited by the potential for improved outcomes for myelofibrosis patients with this promising combination.”