This decision is based on emerging data from the ongoing Phase Ib/III SYMPHONY-1 trial, which evaluates tazemetostat in combination with lenalidomide and rituximab (R2) compared to R2 alone in follicular lymphoma.

The Independent Data Monitoring Committee indicated that, based on adverse events related to secondary hematologic malignancies, the risks could outweigh the potential benefits for patients under this treatment regimen.

In light of these new findings, the French pharmaceutical laboratory is withdrawing Tazverik with immediate effect for both follicular lymphoma (FL) and epithelioid sarcoma (ES).

Alongside the market withdrawal, Ipsen has also taken steps to discontinue tazemetostat treatment for all patients currently enrolled in the SYMPHONY-1 trial. All participants will receive the standard of care (lenalidomide and rituximab).

The study will remain open, without new enrollments, to continue long-term safety monitoring of all participants. Ipsen is also halting all active clinical trials involving tazemetostat and expanded access programs.

"While this outcome is extremely disappointing, patient safety remains our priority," explained Christelle Huguet, Executive Vice President and Head of Research and Development at Ipsen.

Ipsen is collaborating with the U.S. FDA to define the next steps for the withdrawal of Tazverik and to provide all necessary information to finalize the process. Tazverik is marketed in the United States by Ipsen for FL and ES indications.