GSK is going to have to wait a little longer to start delivering a return on its $1.9 billion oncology bet. The FDA has delayed its ruling on the blood cancer candidate momelotinib by three months to provide time to review recently submitted data.
In a statement to disclose the delay, GSK said it “is confident in the momelotinib NDA and looks forward to working with the FDA as they finalize their review.” The statement lacks details of what additional data GSK submitted or an explanation of why it provided the FDA with the information. Whatever the details, the upshot is the regulator's decision date is now Sept. 16.
GSK shared details of the delay on the day it was originally due to receive the FDA ruling. The setback still leaves the U.S. as the likely location of the first approval for momelotinib, with the Big Pharma expecting (PDF) to learn whether the European Medicines Agency will recommend authorization by the end of the year.
Clinical data generated by Sierra Oncology before GSK paid $1.9 billion to buy the biotech suggest the asset has a good shot at winning approval. The phase 3 trial linked momelotinib, a JAK1, JAK2 and ACVR1 inhibitor, to improvements on a myelofibrosis symptom score compared with danazol. Participants had previously received Incyte and Novartis’ JAK inhibitor Jakafi.
One outstanding question ahead of the FDA decision is whether the product label will restrict the use of momelotinib to second-line patients with anemia. GSK’s base case for the Sierra buyout was that the FDA would approve momelotinib in patients with anemia who had previously received another JAK inhibitor.
Securing a first-line approval that would support a direct challenge to Jakafi could enable momelotinib to exceed GSK’s expectations. Asked by an analyst about that prospect earlier this year, Luke Miels, chief commercial officer at GSK, said (PDF), “I will have to bite my tongue.” The FDA delay means Miels will need to keep biting down for a while longer.