Phase III Success for Cabometyx-Tecentriq in Prostate Cancer

Exelixis has recently released comprehensive findings from its Phase III Contact-02 clinical trial, which assessed the efficacy of Cabometyx (cabozantinib) when used alongside Roche’s Tecentriq (atezolizumab) in treating metastatic castration-resistant prostate cancer (mCRPC). The trial demonstrated that the combined therapy significantly lowered the risk of disease progression or mortality by 35% in comparison to an alternative novel hormonal therapy (NHT) in patients who had already received one prior NHT.

Initially reported in August 2023, the study successfully met its primary endpoint of progression-free survival (PFS) in the first 400 patients of the intent-to-treat (ITT) group. The data revealed a median PFS of 6.3 months for the combination treatment, as opposed to 4.2 months for those on hormone therapy alone, with a statistically significant p-value of p=0.0002. The hazard ratio was 0.65, and the p-value was p=0.0007, indicating a substantial benefit from the combined approach.

After a 12-month follow-up, the ITT population showed a median overall survival of 16.7 months, which, although higher than the 14.6 months observed in the hormone therapy group, did not achieve statistical significance with a p-value of p=0.13.

The study’s results were presented at the 2024 Genitourinary Cancers Symposium of the American Society of Clinical Oncology. Exelixis plans to continue the study with a focus on overall survival analysis, with results expected to be released later this year.

In terms of safety, 97% of patients in the trial experienced treatment-emergent adverse events, with grade 5 events occurring in 8% of cases. Notably, 13% of patients had to discontinue the trial due to treatment-related events.

Amy Peterson, Exelixis’ Chief Medical Officer, emphasized the importance of developing a treatment that can delay disease progression and is widely accessible to patients who may not have the resources or desire to seek specialized treatments. She highlighted the company’s commitment to improving the standard of care for advanced prostate cancer patients.

The company intends to discuss the trial outcomes with the FDA, although no specific timeline for the treatment’s progression has been provided. Neeraj Agarwal, the global lead investigator of the trial and senior director for Clinical Research at the Huntsman Cancer Institute, expressed optimism about the potential of the combination therapy to become a widely available treatment option.

In related news, Exelixis halted its Phase III Cabinet trial for Cabometyx in August 2023 after an independent review board determined that the drug significantly extended the time without disease progression or death for pancreatic cancer patients.