Merck's Ogsiveo Becomes First Approved Desmoid Tumor Treatment in Europe
核心洞察
Merck KGaA's SpringWorks (搜索) unit received European Commission approval for Ogsiveo (nirogacestat), marking the first approved therapy for desmoid tumors (搜索) in Europe.
The oral gamma secretase (搜索) inhibitor demonstrated a 71% reduction in disease progression compared to placebo in the phase 3 DeFi trial with 142 patients.
Ogsiveo achieved a 41% objective response rate including 7% complete responses, significantly outperforming the 8% response rate in the control group.
Merck KGaA's recently acquired SpringWorks (搜索) unit has achieved a significant regulatory milestone with the European Commission's approval of Ogsiveo (nirogacestat), becoming the first approved therapy for desmoid tumors (搜索) in Europe. The oral gamma secretase (搜索) inhibitor has been cleared as a monotherapy for adults with progressing desmoid tumors who require systemic treatment.
This approval represents the second major regulatory success for Merck since completing its $3.9 billion acquisition of US biotech SpringWorks (搜索), following last month's EU approval for oral MEK inhibitor Ezmekly (mirdametinib) for neurofibromatosis type 1 (搜索)-related tumors. Both medicines are key components of Merck's strategy to establish a presence in rare tumor treatments.
Clinical Trial Results Drive Approval
The EU approval is based on results from the phase 3 DeFi trial, which enrolled 142 adult patients with progressing desmoid tumors (搜索). These benign but locally aggressive growths affect soft tissues and, while they do not metastasize like cancer, can be debilitating and in rare cases life-threatening when vital structures are impacted.
In the DeFi trial, treatment with Ogsiveo achieved a 71% reduction in disease progression compared to placebo. The drug demonstrated an objective response rate (ORR) of 41%, including 7% complete responses, versus 8% in the control group.
"Desmoid tumors (搜索) can have a profound impact on people's lives and are difficult to manage due to their invasive nature and high rates of recurrence," said Bernd Kasper of the University of Heidelberg (搜索), principal investigator of the DeFi trial. "Until now, there have been no approved medicines in Europe."
Addressing Unmet Medical Need
Desmoid tumors (搜索) present significant treatment challenges, with traditional approaches focusing on surgery, radiotherapy, and chemotherapy. However, systemic treatment is now generally recommended as the frontline option when possible, as recurrence rates after surgery can reach as high as 77%.
Kasper emphasized that "Ogsiveo is a highly innovative therapy with efficacy data demonstrating both meaningful antitumor activity and a significant improvement in desmoid tumor symptoms, including a significant reduction in pain, which is the most debilitating symptom reported by patients."
According to SpringWorks (搜索), now operating as a wholly owned subsidiary of Merck, approximately 1,300 to 2,300 new cases of desmoid tumors (搜索) are diagnosed annually in the EU.
UK Regulatory Approval and Safety Profile
The UK's Medicines and Healthcare products Regulatory Agency (MHRA) also approved nirogacestat hydrobromide (Ogsiveo) for treating progressing desmoid tumors (搜索) in adults on January 7, 2026. The approval was granted under the International Recognition Procedure, with the European Medicines Agency serving as the Reference Regulator.
Julian Beach, MHRA Interim Executive Director of Healthcare Quality and Access, stated: "The approval of nirogacestat hydrobromide will benefit adults with desmoid tumors (搜索), improving health and quality of life."
The drug works by inhibiting the activity of certain proteins involved in tumor growth. Studies have shown that patients taking nirogacestat hydrobromide benefit from living longer without disease progression and avoiding the need for potential surgery.
Safety Considerations
The most common side effects include diarrhea, rash, nausea, tiredness, hypophosphataemia (low blood phosphate levels), headache, and stomatitis (mouth lining inflammation). A serious side effect is premature menopause, which may affect more than 1 in 10 people.
Due to potential harm to unborn babies, nirogacestat hydrobromide must not be taken during pregnancy, and highly effective contraception is required. The drug's effects on fertility and reproductive organs remain uncertain. A patient card will be provided to support pregnancy prevention measures for female patients and female partners of male patients taking the medication.