SpringWorks Therapeutics, part of Merck KGaA, Darmstadt, Germany, announced that the European Commission (EC) has granted marketing authorization for OGSIVEO (nirogacestat), an oral gamma secretase inhibitor, as monotherapy for adults with progressing desmoid tumors requiring systemic treatment. This marks the first and only approved treatment for desmoid tumors in the European Union.
Desmoid tumors are rare, locally aggressive connective tissue tumors that cause severe pain, limited mobility, and other debilitating symptoms. Approximately 1,300 to 2,300 new cases are diagnosed annually in the EU. Due to their invasive nature and high recurrence rates, managing these tumors has been challenging, with medical therapy now recommended over surgery as first-line treatment for many cases.
The EC approval is based on data from the Phase 3 DeFi trial, which showed that OGSIVEO significantly improved progression-free survival, reducing the risk of disease progression by 71% compared to placebo. The trial also demonstrated a 41% objective response rate with OGSIVEO versus 8% with placebo, along with improvements in pain, physical function, and overall quality of life.
“OGSIVEO is a highly innovative therapy with meaningful antitumor activity and significant symptom improvement, including pain reduction, the most debilitating symptom reported by patients,” said Dr. Bernd Kasper, principal investigator of the DeFi trial.
Lynne Hernandez, Executive Director of the Desmoid Tumor Research Foundation, welcomed the approval as a long-awaited advancement that could improve awareness, diagnosis, and outcomes for patients.
SpringWorks CEO Dr. Danny Bar-Zohar expressed gratitude to patients, families, investigators, and advocates, highlighting the company’s commitment to rare tumors. OGSIVEO is already the standard systemic therapy for desmoid tumors in the U.S., and this approval allows the company to extend those benefits to European patients.
OGSIVEO’s safety profile includes manageable side effects such as diarrhea, rash, ovarian toxicity in women of childbearing potential, nausea, fatigue, and headache.
The approval comes shortly after another EC approval of a SpringWorks/Merck KGaA therapy for NF1-PN, underscoring the company’s expanding portfolio of innovative treatments for rare tumors.