On March 9, 2026 Ipsen (Euronext: IPN; ADR: IPSEY) reported that it is voluntarily withdrawing Tazverik (tazemetostat) in all indications from all Ipsen markets. Ipsen’s decision to withdraw is based on emerging data from the ongoing Phase Ib/III SYMPHONY-1 trial (evaluating tazemetostat in combination with lenalidomide plus rituximab (R2) vs R2 in follicular lymphoma). The Independent Data Monitoring Committee (IDMC) advised that, based on adverse events of secondary hematologic malignancies, the risks may outweigh potential benefits for patients within this treatment regimen. As a result of these data, Ipsen is withdrawing Tazverik effective immediately, including both for follicular lymphoma (FL) and epithelioid sarcoma (ES).

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In addition to withdrawing Tazverik from the market, Ipsen has initiated steps to stop treatment with tazemetostat for all patients currently enrolled in the ongoing SYMPHONY-1 trial. All participants will receive standard of care, lenalidomide plus rituximab only. The study will remain open, with no further enrolment, to continue the long-term safety follow-up of all participants. Ipsen is also discontinuing all active tazemetostat clinical trials and expanded access programs.

"While this is an extremely disappointing outcome, the safety of patients remains our priority", said Christelle Huguet, PhD & EVP Head of R&D at Ipsen. "Emerging data from this confirmatory study have highlighted a safety profile that is unfavorable compared to that previously observed in clinical evaluation. We will now work closely with investigators and clinical teams to support patients through the respective next steps and transition plans."

Ipsen is working with the United States (U.S.) Food and Drug Administration (FDA) on the next steps to execute the withdrawal of Tazverik and provide all necessary information to complete this process. Tazverik is marketed in the U.S. by Ipsen in FL and ES. Tazverik received accelerated approval from the U.S. FDA in 2020 for adults with relapsed or refractory FL whose tumors are positive for an EZH2 mutation and who have received at least two prior therapies as well as relapsed or refractory FL adult patients who have no satisfactory alternative treatment options. Tazverik also received U.S. FDA accelerated approval in 2020 for the treatment of adults and adolescents aged 16 years and older with metastatic or locally advanced epithelioid sarcoma not eligible for complete resection.

The withdrawal is not expected to impact the Company’s financial guidance.

About Tazverik
Tazverik is an EZH2 inhibitor indicated in the U.S. for the treatment of:
Adults and pediatric patients aged 16 years and older with metastatic or locally advanced epithelioid sarcoma not eligible for complete resection.
Adult patients with relapsed or refractory follicular lymphoma whose tumors are positive for an EZH2 mutation as detected by an FDA-approved test and who have received at least two prior systemic therapies.
Adult patients with relapsed or refractory follicular lymphoma who have no satisfactory alternative treatment options.
These indications are approved under accelerated approval regulatory pathways based on overall response rate and duration of response. Continued approval for these indications may be contingent upon verification and description of clinical benefit in confirmatory trials.
View the U.S. Full Prescribing Information here
Tazverik is available in Japan, Macau, Hong Kong & China via Ipsen partners.

About SYMPHONY-1
SYMPHONY‑1 (EZH‑302; NCT04224493) is an Ipsen‑led global Phase Ib/III study evaluating Tazverik in combination with lenalidomide and rituximab (R²) as a second‑line therapy for relapsed/refractory follicular lymphoma. This study also serves as the confirmatory trial required under the accelerated approval pathway for Tazverik in follicular lymphoma.

The trial spans 229 sites across 15 countries, including the U.S., EU, China, and others, and includes independently powered analyses for EZH2‑wild‑type and EZH2‑mutant patient populations.

(Press release, Ipsen, MAR 9, 2026, View Source [SID1234663366])