Ipsen withdraws cancer drug following safety concerns

According to the company, data from the SYMPHONY 1 study revealed an alarming risk profile, prompting an independent monitoring committee to conclude that the potential risks outweigh the therapeutic benefits. The main concern centres on secondary haematological malignancies – new cancers potentially linked to the drug itself. As a result, Ipsen has voluntarily withdrawn the drug and halted the trial. According to the company, the step is not expected to affect its financial forecasts.

Tazverik (tazemetostat), an EZH2 methyltransferase inhibitor, received accelerated approval from the US FDA in 2020 for two rare and hard-to-treat cancers: follicular lymphoma and epithelioid sarcoma. At the time, the therapy was hailed as a long-awaited option for patients with limited treatment choices. However, the conditional approval was contingent on confirmatory clinical data – a role filled by the ongoing SYMPHONY 1 trial.

Patients transitioned to standard care

The SYMPHONY-1 study compared a combination of Tazverik, lenalidomide and rituximab with a standard treatment regimen without Tazverik. The trial was conducted at 229 sites across 15 countries, including the US, Europe and China. All enrolled patients are now being transitioned to standard therapy, and no new participants will be recruited. While the study remains open for long-term safety monitoring, Ipsen has also suspended all other clinical trials and expanded access programmes involving tazemetostat.

“While this is an extremely disappointing outcome, the safety of patients remains our priority,” said Christelle Huguet, PhD, EVP and Head of R&D at Ipsen. “Emerging data from this confirmatory study have highlighted a safety profile that is unfavourable compared with 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.”

Global coordination and limited financial impact

Ipsen is now working with regulatory authorities, including the FDA and EMA, to formalise the product withdrawal. Its partner Hutchmed has notified health authorities in China, Hong Kong and Macau, suspended all sales and deliveries, and instructed healthcare providers and pharmacies to discontinue use of the product. Patients currently receiving Tazverik will have to find alternative treatments.

Despite the global scale of the withdrawal, Ipsen expects limited financial repercussions. Modest sales of Tazverik mean the company is maintaining its existing financial outlook.

Ipsen’s share price fell noticeably, though not catastrophically, following the withdrawal announcement. The company now faces the task of analysing long-term safety data and drawing lessons from a case that underscores the delicate balance between accelerated access and patient safety.