Leap Therapeutics' Sirexatamab Shows Promise in Treating Microsatellite Stable Colorectal Cancer
- Leap Therapeutics reports promising Phase 2 results for sirexatamab in treating microsatellite stable colorectal cancer patients.
- The study shows a 38.0% objective response rate for sirexatamab, outperforming the control group's 23.7%.
- Leap aims to advance sirexatamab into biomarker-focused trials, enhancing targeted therapy efficacy for CRC patients.
Leap Therapeutics Advances Immuno-Oncology with Promising Data on Sirexatamab
Leap Therapeutics, Inc., a biotechnology firm specializing in targeted and immuno-oncology therapeutics, makes significant strides in the fight against microsatellite stable (MSS) colorectal cancer (CRC) with the latest findings from the DeFianCe study. This Phase 2 clinical trial, specifically Part B, evaluates the efficacy of sirexatamab (DKN-01), an anti-DKK1 monoclonal antibody, in conjunction with bevacizumab and chemotherapy. The results, recently presented by Dr. Zev Wainberg at the European Society for Medical Oncology (ESMO) Congress 2025, highlight the drug’s potential to improve outcomes for CRC patients who have not responded effectively to prior systemic therapies.
The study focuses on a specific patient demographic—those with elevated DKK1 levels, a recognized negative prognostic biomarker in CRC. Among the 88 patients analyzed, the objective response rate (ORR) for those treated with sirexatamab was 38.0%, significantly higher than the 23.7% observed in the control group receiving standard treatment. The median progression-free survival (mPFS) of the sirexatamab cohort was also notably superior, reported at 9.03 months compared to 7.06 months for the control group, showcasing a hazard ratio of 0.61 and a statistically significant p-value of 0.0255. These findings suggest that sirexatamab may provide a meaningful therapeutic option for patients with high DKK1 levels, indicating a potential shift in treatment paradigms for this challenging subset of CRC patients.
Leap Therapeutics is particularly optimistic about these results, as they bolster the case for advancing sirexatamab into biomarker-focused registrational trials. The data not only demonstrate improved objective response and progression-free survival rates but also hint at promising overall survival outcomes. While the median overall survival (mOS) for the sirexatamab group has yet to be reached, the control group shows an mOS of 14.39 months, with a hazard ratio of 0.42 and a p-value of 0.0118. These statistics provide further validation for the continued exploration of sirexatamab as a key therapeutic agent in treating CRC patients with elevated DKK1 levels.
In addition to the promising clinical data, Leap Therapeutics emphasizes the importance of biomarker identification in developing targeted therapies. By focusing on patient populations that are more likely to benefit from specific treatments, the company aims to enhance the efficacy and safety of new immuno-oncology agents. As the field of cancer therapeutics evolves, Leap's commitment to innovation and patient-centric approaches positions it as a key player in the ongoing battle against colorectal cancer.