SpringWorks Therapeutics Unveils Promising Long-Term Data for OGSIVEO®

SpringWorks Therapeutics, Inc. has published new long-term efficacy and safety data from the Phase 3 DeFi trial of OGSIVEO® (nirogacestat). This oral gamma secretase inhibitor is designed for the treatment of adults facing progressing desmoid tumors requiring systemic therapy. The findings were released on October 21, 2025, in the Journal of Clinical Oncology (JCO).

The DeFi trial was a comprehensive global study that involved randomization, multicenter participation, and a double-blind, placebo-controlled design. Earlier, the long-term follow-up data had been presented at the 2024 Connective Tissue Oncology Society Meeting. The newly published results utilized a cutoff date from December 2024, marking the final data cut of the clinical trial.

Data from this latest analysis indicate that extended treatment with OGSIVEO is linked to further reductions in tumor size. Notably, there was an increase in the objective response rate (ORR), with additional partial responses (PRs) and complete responses (CRs) recorded. Furthermore, patients reported sustained improvements in their overall health outcomes, all while maintaining a consistent safety profile compared to the prior analysis cut-off from April 2022.

Dr. Ravin Ratan, M.D., M.Ed., an Associate Professor at the Department of Sarcoma Medical Oncology at The University of Texas MD Anderson Cancer Center, and the lead author of the JCO publication, emphasized the significance of these findings. He stated, “Desmoid tumors are locally aggressive and complex tumors whose unpredictable growth can cause significant pain, functional impairment, and emotional distress. For many patients, these tumors disrupt daily life in ways that are often underestimated, so advancing treatment options that offer durable symptom relief and tumor control can make a meaningful difference for patients.”

Dr. Ratan also highlighted that the optimal duration of therapy may differ among patients. He noted that decisions regarding treatment length should ideally be made collaboratively between patients and their healthcare providers. The new data published in JCO provides valuable insights into the long-term safety and efficacy of nirogacestat, which can enhance treatment strategies and improve patient care.

The complete publication in the Journal of Clinical Oncology can be accessed online for further details on the study’s findings. As the landscape of treatment options for desmoid tumors evolves, this new evidence may play a crucial role in shaping future therapeutic approaches for affected individuals.