Ipsen is halting sales of its cancer drug Tazveric, which it acquired through its acquisition of Epizyme less than four years ago, after an independent data monitoring board flagged its safety in clinical trials.
The move may not have a major impact on Ibsen’s financial performance, but it could shake confidence in the company’s business development acumen, at least one analyst group argues.
Specifically, the Paris-based drugmaker is voluntarily withdrawing tazveric, also known as tazemetostat, from all indications and all markets, including the United States, where the company holds commercial rights to the EZH2 inhibitor, according to a March 9 press release.
Ibsen said it was advised by a data monitoring committee that observed “secondary hematologic malignancy adverse events” in the Tazverik study that led to the cancellation, and determined that “the risks of this treatment plan may outweigh the potential benefits to patients.”
The company also said it has begun the process of discontinuing Tazveric treatment for patients enrolled in the Phase 1b/3 Symphony-1 trial that showed safety signals in blood cancers. The study looked at Ipsen’s drug in combination with Revlimid and Rituxan in relapsed or refractory follicular lymphoma. The drug company said it will continue long-term safety follow-up of all participants in the study and will further discontinue “all ongoing tazemetostat clinical trials and expanded access programs.”
Ibsen telegraphed plans to acquire Epizyme and FDA-approved Tazveric in June 2022, two years after it was approved in the U.S. to treat epithelioid sarcoma and follicular lymphoma. Ibsen said Monday’s market withdrawal announcement applies to both approved uses.
Ibsen’s Chinese partner, HatchMed, also began recalling Tazverik in mainland China, Hong Kong and Macau, and halting research for which it was responsible, according to a separate press release on Monday.
“While this is an extremely disappointing result, patient safety remains our top priority,” Dr. Christelle Huguet, Ipsen’s head of research and development, said in a statement. “Newly available data from this confirmatory study highlight an unfavorable safety profile compared to that observed in previous clinical evaluations.”
She continued, “We will continue to work closely with our researchers and clinical teams to support patients through their respective next steps and transition plans.”
Removing Tazverik from the value equation will have a “minor impact” on Ibsen’s profile, Jefferies analysts said in a note to clients on Monday, citing the drug’s “low sales” to date. Moreover, Ibsen himself said in his 2025 earnings report last month that he no longer expected Tazverik to meet the company’s peak sales target of more than 500 million euros and had written down the product.
Ipsen said sales of Tazverik fell 13% last year, down 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 the note. Ipsen’s trading strategy could become increasingly important in the coming years, analysts said, as Ipsen faces an expected patent cliff with cancer drugs such as Decapeptyl, Cabometyx and Onivide.
Ibsen’s stock price fell about 3% Monday morning (ET). The company said it does not expect the withdrawal of Tazverik to have an impact on its earnings forecast.
The company recently reported total sales of 3.68 billion euros (approximately $4.3 billion) in 2025 and said it expects sales growth of more than 13% in 2026.
