Phase 3 KeyVibe-008 Trial of Vibostolimab Plus Pembrolizumab in ES-SCLC Discontinued

The phase 3 KeyVibe-008 trial has been discontinued based on the recommendations of an independent data monitoring committee, according to an announcement from Merck.

The trial was evaluating an investigational fixed-dose combination of the anti-TIGIT antibody vibostolimab and the anti–PD-1 therapy pembrolizumab plus chemotherapy and comparing it with atezolizumab plus chemotherapy as a first-line treatment of patients with extensive-stage small cell lung cancer (ES-SCLC).

“At a preplanned analysis, data showed that the primary end point of overall survival met the prespecified futility criteria,” company officials said in announcement. “Additionally, when compared [with] patients in the control arm, patients in the vibostolimab and pembrolizumab fixed-dose combination arm experienced a higher rate of adverse events (AEs) and immune-related AEs. A comprehensive analysis of this study is ongoing.”

Merck officials said they are notifying study investigators of the decision and that patients should stop treatment with fixed-dose vibostolimab and pembrolizumab and be offered atezolizumab as a treatment option. The trial results will be shared with the scientific community, according to the announcement.

Ongoing phase 3 studies evaluating the vibostolimab and pembrolizumab fixed-dose combination in lung cancer include KeyVibe-003, KeyVibe-006, and KeyVibe-007. These studies are “routinely monitored by external data monitoring committees,” and “interim external data monitoring committee safety reviews have not resulted in any study modifications to date, and the studies are undergoing ongoing comprehensive safety monitoring,” according to Merck.

Source: Merck