The follicular lymphoma market is thinning out fast. Days after Gilead Sciences pulled an accelerated approval for Zydelig in the indication, Incyte has withdrawn a submission for approval of its rival PI3K inhibitor in response to talks with the FDA about confirmatory studies.
Incyte filed for FDA approval of its PI3Kδ inhibitor parsaclisib in the treatment of relapsed or refractory follicular lymphoma, marginal zone lymphoma and mantle cell lymphoma last year on the strength of phase 2 data. The filing positioned Incyte to win accelerated approvals in the indications this year and then perform confirmatory phase 3 studies to validate the signs of efficacy seen in the earlier trials.
However, after talking to the FDA, Incyte concluded it cannot complete the confirmatory trials “within a time period that would support the investment.” The action comes hot on the heels of similar moves by Gilead and Secura Bio.
Gilead won accelerated approval for Zydelig, which, like parsaclisib, is a PI3K inhibitor, in 2014 and had to run confirmatory trials to stay on the market. Recently, Gilead decided to withdraw accelerated approval in two indications, including follicular lymphoma, because the evolution of the treatment landscape has made enrollment in the confirmatory study “an ongoing challenge.”
Secura Bio exited the market just ahead of Gilead after determining “the current treatment landscape for FL patients in the U.S. and the logistics, cost and timing of the postmarketing requirements for Copiktra in FL was no longer merited.” Copiktra is another PI3K inhibitor.
Even after the flurry of exits, there is still a small band of companies interested in using PI3K inhibitors to treat the diseases. Bayer filed for full FDA approval of PI3K inhibitor Aliqopa in follicular lymphoma and other indications last year, having generated phase 3 data that could support the conversion of its earlier accelerated approval.
MEI Pharma is looking to join Bayer in the market. Working with partner Kyowa Kirin, MEI plans to win accelerated approval for PI3Kδ inhibitor zandelisib and then confirm its efficacy in a phase 3 trial that got underway last year.