Sierra Oncology Bets $216M On AstraZeneca's BET Inhibitor For Myelofibrosis

Sierra Oncology Inc SRRA has acquired an exclusive global license from AstraZeneca Plc AZN for AZD5153, a potent, and selective BRD4 BET inhibitor with a novel bivalent binding mode.
Sierra plans to initiate a Phase 2 study evaluating momelotinib in combination with AZD5153 in myelofibrosis patients in 1H of 2022.
Under the agreement terms, Sierra will make a one-time, non-refundable upfront cash payment of $8 million to AstraZeneca.
In addition, Sierra will pay AstraZeneca up to $208.0 million in milestone payments and a tiered high single-digits to low double-digits sales-based royalty.
But unlike other currently available JAK inhibitors, momelotinib doesn’t cause a reduction in platelet count (myelosuppression), meaning it could potentially be given in higher doses.
Also, AZD5153 binds at two active binding sites within BRD4, as opposed to one at a time, which the company believes contributes to its potency.
Sierra Oncology ended the June quarter with cash and cash equivalents of $90.7 million.
Price Action: SRRA closed at $17.13 on Thursday, AZN shares are down 1.56% at $57.50 during the premarket session on the last check Friday.