Tazverik Removed From Market Due to Cancer Concerns

Links to potential secondary blood cancers detected during a postmarketing study require immediate market removal, according to the manufacturer.

The lymphoma drug Tazverik (tazemetostat) is being pulled from pharmacy shelves due to potential cancer risks just six years after it was first approved through a federal fast-track approval process.

French drug manufacturer Ipsen issued a press release on March 9 announcing the medication’s market removal after independent observers linked the drug to secondary cancer risks during a post-marketing clinical trial.

Tazverik was first approved by the U.S. Food and Drug Administration (FDA) in 2020 for the treatment of follicular lymphoma, a slow growing cancer of the lymph nodes, and epithelioid sarcoma, a rare soft tissue cancer that typically develops in the arms or legs. The drug received accelerated approval based on results from single arm clinical trials that evaluated its effectiveness without comparison to another treatment.

Tazverik is designed to target and inhibit EZH2, an enzyme involved in regulating gene activity that can promote tumor growth when mutated or overactive. By blocking this enzyme, the therapy aims to slow the spread of cancer cells and limit tumor progression in patients with certain cancers.

However, Ipsen stated this week that it will voluntarily withdraw Tazverik from the market after emerging data from the Phase Ib/III SYMPHONY-1 clinical trial found patients receiving the drug experienced higher rates of secondary blood cancers.

The safety concerns emerged during an ongoing global clinical trial known as SYMPHONY-1, which was evaluating Tazverik in combination with the immunotherapy drugs lenalidomide (Revlimid) and rituximab (Rituxan) for patients with relapsed or refractory follicular lymphoma. The study was designed to serve as the confirmatory trial required under the FDA’s accelerated approval pathway.

According to Ipsen, the trial’s Independent Data Monitoring Committee (IDMC), which oversees patient safety during clinical studies, reviewed preliminary trial data and identified higher rates of secondary hematologic malignancies among patients receiving Tazverik as part of the treatment regimen.

Based on those findings, the monitoring committee concluded that the safety risks associated with the therapy may outweigh its potential benefits for patients participating in the study.

Ipsen indicated the withdrawal will take effect immediately and that treatment with Tazverik will be halted for all patients currently enrolled in the SYMPHONY-1 trial. Those participants will instead continue receiving standard therapy with lenalidomide and rituximab while researchers continue long-term safety monitoring.

“While this is an extremely disappointing outcome, the safety of patients remains our priority. Emerging data from this confirmatory study have highlighted a safety profile that is unfavorable compared to that previously observed in clinical evaluation.”

– Dr. Christelle Huguet, Ipsen head of R&D

The company says it is working with the FDA on the next steps to complete the market withdrawal and ensure physicians and patients receive updated safety information.

FDA Accelerated Approval Program Concerns

The withdrawal of Tazverik also adds to ongoing criticism of the FDA’s Accelerated Approval Program, which allows certain drugs, particularly cancer treatments, to reach the market years earlier than under the traditional approval process. Under this pathway, medications can be approved based on early clinical data, with manufacturers required to later confirm the drug’s effectiveness and safety through follow-up studies.

However, researchers and health policy experts have increasingly questioned whether those confirmatory trials consistently demonstrate real patient benefits.

A 2024 study found that about 41% of cancer drugs granted accelerated approval failed to show meaningful clinical benefits within five years of reaching the market. Researchers from Harvard University and Brigham and Women’s Hospital reported that among 129 cancer drugs approved between 2013 and 2017, 22% were ultimately withdrawn, while another 15% remained on the market even after studies failed to confirm their effectiveness.

Additional research has also raised concerns about safety disclosures for drugs approved through the expedited pathway. A 2017 study found that 94% of medications granted accelerated approval later required label updates due to newly identified risks or side effects, compared to about 68% of drugs approved through the traditional, longer review process.

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