According to a story from AJMC, the drug developer Incyte has made the decision to withdraw its New Drug Application (NDA) for its investigational therapy parsaclisib. This therapy was submitted for approval to the US Food and Drug Administration (FDA) in November last year as a treatment for three rare lymphomas: mantle cell lymphoma, relapsed/refractory follicular lymphoma, and marginal zone lymphoma.

Parsaclisib is classified as an inhibitor of PI3K delta and was previously granted Priority Review for marginal zone and mantle cell lymphoma after promising trial results showing good tolerability and safety profile. The company’s decision was purely due to business considerations, not due to poor performance of parsaclisib.

The move follows communication with the agency in regards to:

“Confirmatory studies to support an accelerated approval, which Incyte determined cannot be completed within a time period that would support the investment.”

The decision does not impact any other ongoing trials with the drug. The move follows several other withdrawals, such as Gilead Sciences decision regarding idelalisib, its own PI3K delta inhibitor, which had previously been submitted for relapsed small lymphocytic lymphoma and relapsed follicular B-cell non-Hodgkin lymphoma. This was once again a decision based on difficulties surrounding the completion of confirmatory studies that further verified the beneficial profile of the drug. This drug is still fully approved for treating chronic lymphocytic leukemia and follicular lymphoma.

These confirmatory studies are an essential aspect of the Accelerated Approval process in which a drug can be approved more quickly based on surrogate endpoints. But, to keep the approval, confirmatory trials are a requirement. This requirement is not always easily met, especially in rare cancers and other conditions in which recruiting patients can be a challenge.

Hopefully, other new treatments for these rare cancers will soon be on the horizon for approval.