Dr Somaiah on Efficacy Data for Bezuclastinib Plus Sunitinib in Advanced GIST

“[These data] were encouraging; they translate to a 50% reduction in the risk of progression or death on the combination vs sunitinib alone.… When you keep that disease suppressed, the chance of having additional secondary alterations is lower; that allows [patients] to stay on the drug longer.”

Neeta Somaiah, MD, a professor and department chair of Sarcoma Medical Oncology at The University of Texas MD Anderson Cancer Center discussed efficacy data for bezuclastinib (CGT0486) plus sunitinib (Sutent) for patients with advanced gastrointestinal stromal tumors (GIST) from the phase 3 Peak study (NCT05208047) and how they compare to efficacy with first-line treatments like imatinib (Gleevec).

Want to learn more about the combination in GIST? Be sure to read the full exclusive interview with Somaiah.

Data from the study showed that patients who received the combination (n = 204) experienced a median progression-free survival (PFS) of 16.5 months (95% CI, 13.8-19.2) vs 9.2 months (95% CI, 7.2-11.0) for those who received sunitinib alone (n = 209; HR, 0.50; 95% CI, 0.39-0.65; P < .0001). Moreover, the combination arm achieved an overall response rate of 45.6% (95% CI, 38.6%-52.7%) compared with 25.8% (95% CI, 20.0%-32.3%) with sunitinib monotherapy (P < .0001).

Somaiah began by underscoring the PFS data for each arm in the trial, noting that data for the combination outperform that with other post-imatinib treatments for GIST. When compared with sunitinib alone, the combination led to a 50% reduction in the risk of disease progression or death, she added. However, Somaiah also explained how the data with sunitinib monotherapy in Peak were still encouraging and better than previously reported data for the TKI vs placebo. Better understandings of the adverse effects associated with sunitinib and more sophisticated treatment strategies helped contribute to improved monotherapy data with this agent, she said.

Somaiah then moved into a discussion of the response data for the combination from Peak, pointing out how first-line imatinib response data have been shown to be similar. Ultimately, Somaiah concluded by explaining how bezuclastinib plus sunitinib helps suppress disease in patients with focal progression through addressing resistant clones. She also emphasized the need for more overall survival data with this regimen.