Safety Concerns Prompt Ipsen to Voluntarily Withdrawal Tazemetostat in Follicular Lymphoma and Epithelioid Sarcoma

Clinical Summary:

• Based on emerging safety data from the SYMPHONY-1 trial, Ipsen has voluntarily withdrawn tazemetostat from all indications and markets after findings suggested an unfavorable benefit-risk profile in patients with relapsed or refractory follicular lymphoma.
• Ipsen has halted treatment, discontinued all active trials and expanded access programs, and initiated global withdrawal.
• This withdrawal underscores the challenges of confirmatory trials under accelerated approval and eliminates tazemetostat as a treatment option in follicular lymphoma and epithelioid sarcoma.

Based on emerging safety data from the SYMPHONY-1 trial, Ipsen has voluntarily withdrawn tazemetostat (Tazverik®) from all indications and markets, including follicular lymphoma (FL) and epithelioid sarcoma. 

This decision follows a recommendation from the Independent Data Monitoring Committee, which determined that an increased incidence of secondary hematologic malignancies in the tazemetostat-containing arm raised significant safety concerns and these risks may outweigh the potential benefits.

In this randomized, phase 1b/3 study, patients with relapsed or refractory FL received either tazemetostat plus lenalidomide and rituximab or lenalidomide plus rituximab alone. Primary objectives included efficacy and long-term safety in both EZH2-mutant and wild-type populations. The trial served as the confirmatory study required under the accelerated approval pathway for FL. 

Based on these findings, Ipsen has withdrawn tazemetostat effective immediately in all markets and is working with the US Food and Drug Administration (FDA) to execute the withdrawal process and provide necessary regulatory documentation. All ongoing tazemetostat clinical trials and expanded access programs have been discontinued and patients enrolled in the SYMPHONY-1 trial will transition to standard-of-care therapy with lenalidomide plus rituximab. The study will remain open for long-term safety follow-up, although no further enrollment will occur. 

Tazemetostat received accelerated approval in 2020 for adult patients with EZH2-mutated relapsed or refractory FL who previously received at least 2 lines of prior therapy, as well as for patients without satisfactory treatment options.

It also received accelerated approval in 2020 for adults and pediatric patients 16 years of age and older with metastatic or locally advanced epithelioid sarcoma not eligible for complete resection. These approvals were granted under the accelerated approval pathway based on overall response rate and duration of response, contingent upon verification of clinical benefit in confirmatory trials.

“While this is an extremely disappointing outcome, the safety of patients remains our priority,” stated Christelle Huguet, PhD, Executive Vice President and head of research and development at Ipsen. “We will now work closely with investigators and clinical teams to support patients through the respective next steps and transition plans.” 

Source:

Ipsen. Ipsen voluntarily withdraws Tazverik® (tazemetostat) in follicular lymphoma and epithelioid sarcoma. Accessed on May 13, 2026. https://www.ipsen.com/press-release/ipsen-voluntarily-withdraws-tazverik-tazemetostat-in-follicular-lymphoma-and-epithelioid-sarcoma-3251503/