Lung cancer trial halted due to lack of survival benefit, higher toxicity
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A randomized phase 3 trial designed to compare two combinations for first-line treatment of lung cancer has been halted after an interim analysis revealed no survival benefit and more toxicity with the experimental regimen.
The double-blind KeyVibe-008 trial included 460 patients with extensive-stage small cell lung cancer.
Researchers randomly assigned half of the patients to a fixed-dose combination of vibostolimab (Merck) — an investigational anti-T-cell immunoglobulin and ITM domain (TIGIT) antibody, and pembrolizumab (Keytruda, Merck), an anti-PD-1 antibody. Patients received the agents in combination with etoposide and platinum chemotherapy for approximately 12 weeks, and then received more cycles of fixed-dose vibostolimab and pembrolizumab.
The other half of study participants received atezolizumab (Tecentriq, Genentech) in combination with etoposide and platinum chemotherapy for approximately 12 weeks, followed by more cycles of atezolizumab.
OS served as the primary endpoint. Secondary endpoints included PFS, objective response rate and duration of response.
Results of a pre-planned analysis showed OS outcomes met the prespecified futility criteria. Researchers also reported a higher rate of adverse events and immune-related adverse events in the vibostolimab-pembrolizumab group.
Study investigators have been notified that patients should stop receiving treatment with the vibostolimab-pembrolizumab combination and be offered the option to receive atezolizumab.
“Small cell lung cancer remains a difficult disease to treat, as evident by the 7% 5-year survival rate and limited advancements in treatment options,” Marjorie Green, MD, senior vice president and head of oncology global clinical development for Merck Research Laboratories, said in a company press release. “Innovative research plays a critical role in improving our understanding to help patients achieve better outcomes, and while we hoped the results would be different, we remain committed to investigating novel approaches to treat this debilitating disease.”