After an independent data monitoring committee raised safety flags in a clinical trial, Ipsen is shutting down the cancer med Tazverik, which it picked up through its acquisition of Epizyme less than four years ago.
While the move may not have a major impact on Ipsen’s financial performance, it could shake confidence in the company’s business development acumen, at least one group of analysts contends.
Specifically, the Paris-based drugmaker is voluntarily withdrawing Tazverik, also known as tazemetostat, across all indications and in all markets—including the U.S.—where it holds commercial rights to the EZH2 inhibitor, according to a March 9 press release.
On the advice of a data monitoring committee that observed “adverse events of secondary hematologic malignancies” in the Tazverik study that prompted the withdrawal, Ipsen said it determined “the risk may outweigh potential benefits for patients within this treatment regimen.”
The company said it has also started the process of stopping Tazverik treatment in patients enrolled in its phase 1b/3 Symphony-1 trial, where the blood cancer safety signals emerged. That study was looking at a combination of Ipsen’s drug with Revlimid plus Rituxan in relapsed or refractory follicular lymphoma. The drugmaker said it will continue long-term safety follow-up on all participants in the study and further nix “all active tazemetostat clinical trials and expanded access programs.”
Ipsen telegraphed plans to acquire Epizyme and the FDA-approved Tazverik in June 2022, two years after the med’s clearance in the U.S. as both an epithelioid sarcoma and a follicular lymphoma treatment. Monday’s market withdrawal announcement applies to both approved uses, Ipsen said.
Ipsen’s partner in China, Hutchmed, has also begun to recall Tazverik in mainland China, Hong Kong and Macau and axe studies it was in charge of, according to a separate press announcement Monday.
“While this is an extremely disappointing outcome, the safety of patients remains our priority,” Christelle Huguet, Ph.D., Ipsen’s R&D chief, said in a statement. “Emerging data from this confirmatory study have highlighted a safety profile that is unfavorable compared to that previously observed in clinical evaluation.”
She continued: “We will now work closely with investigators and clinical teams to support patients through the respective next steps and transition plans.”
Taking Tazverik out of its value equation would have a “minor impact” on Ipsen’s profile, analysts at Jefferies wrote in a note to clients Monday, citing “lackluster sales” of the drug to date. What’s more, Ipsen itself said in its 2025 earnings report last month that it no longer expects (PDF) Tazverik to hit the company’s 500 million-euro-plus peak sales target and that it has taken an impairment on the product.
Ipsen logged a 13% decline in Tazverik sales last year, or 9.1% at constant exchange rates, with the drug bringing in 40.6 million euros (about $47 million) in 2025.
The drug’s meandering sales and the “high risk” nature of Ipsen’s Symphony-1 trial have recently “put some scrutiny on management’s business development credibility,” the Jefferies team added in its note. Ipsen’s dealmaking strategy could become increasingly important in the coming years as the drugmaker runs up against expected patent cliffs for cancer medicines like Decapeptyl, Cabometyx and Onivyde, the analysts said.
Ipsen’s share price was down roughly 3% Monday morning ET. The company said it does not expect the Tazverik withdrawal to affect its financial forecast.
The company recently reported total sales of 3.68 billion euros (around $4.3 billion) in 2025 and said it expects to chart sales growth greater than 13% in 2026.