The firms’ one-time hemophilia B gene therapy has been approved in the EU just months after a US nod, but concerns remain about its prospects on a market that has seen several setbacks for other gene therapies.

The firms’ partnership goes back to pre-merger Celgene, and BMS still has Dragonfly candidates in its pipeline. Ji Xing gets hypertension candidate from Phase Bio.

Pfizer’s fidanacogene elaparvovec has hit the mark in a Phase III hemophilia B trial just a month after rival UniQure’s Hemgenix won US approval, with Pfizer’s plans for regulatory action raising the stakes for Hemgenix.

While Hemgenix has courted criticism since its $3.5m price tag was unveiled, a drug pricing expert has told Scrip discounts and value-based agreements could make the therapy more palatable to payers.