Trial results for the KEYVIBE-003 study (NCT04738487) investigating the coformulation of pembrolizumab/vibostolimab versus pembrolizumab monotherapy in metastatic non-small cell lung cancer (NSCLC) were posted on ClinicalTrials.gov on 2025-08-26. The study found that the coformulation did not demonstrate an improvement in overall survival compared to pembrolizumab alone, with median overall survival for pembrolizumab monotherapy reaching 20.3 months in participants with PD-L1 TPS ≥50%, versus 15.7 months for the coformulation in the same group.
Background
The study investigated treatment for PD-L1 positive metastatic non-small cell lung cancer (NSCLC). Pembrolizumab (Keytruda) is an established immunotherapy. The trial aimed to assess if adding vibostolimab as a coformulation would enhance outcomes in this patient population.
Trial design
The KEYVIBE-003 study (NCT04738487) was a Phase 3 trial that enrolled 1264 participants. The study investigated the coformulation of pembrolizumab/vibostolimab against pembrolizumab monotherapy in individuals with PD-L1 positive metastatic non-small cell lung cancer. The trial's objective was to determine if the coformulation would lead to longer overall survival and progression-free survival.
Key results
The trial results for Overall Survival (OS) were reported across different PD-L1 expression levels:
- For participants with PD-L1 Tumor Proportion Score (TPS) ≥50%:
- Median OS in the Pembrolizumab/Vibostolimab group was 15.7 Months.
- Median OS in the Pembrolizumab group was 20.3 Months.
- For participants with PD-L1 TPS ≥1%:
- Median OS in the Pembrolizumab/Vibostolimab group was 15.0 Months.
- Median OS in the Pembrolizumab group was 16.4 Months.
- For participants with PD-L1 TPS 1% to 49%:
- Median OS in the Pembrolizumab/Vibostolimab group was 14.3 Months.
- Median OS in the Pembrolizumab group was 14.3 Months.
Key analyses for Overall Survival showed:
- A Hazard Ratio (HR) of 1.06 (95% Confidence Interval: 0.83 to 1.35) with a p-value of 0.6712.
- A Hazard Ratio (HR) of 0.96 (95% Confidence Interval: 0.82 to 1.13) with a p-value of 0.332.
- A Hazard Ratio (HR) of 0.9 (95% Confidence Interval: 0.72 to 1.11) with a p-value of 0.1646.
What this means
The results of the KEYVIBE-003 trial indicate that the coformulation of pembrolizumab/vibostolimab did not demonstrate an overall survival benefit compared to pembrolizumab monotherapy in patients with PD-L1 positive metastatic non-small cell lung cancer. For the subgroup with PD-L1 TPS ≥50%, median OS was numerically lower in the coformulation arm. The Hazard Ratios close to 1.0 and the non-significant p-values across different PD-L1 expression levels suggest that adding vibostolimab in this coformulation did not improve efficacy over pembrolizumab alone for this patient population.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT04738487, titled "Coformulation of Pembrolizumab/Vibostolimab (MK-7684A) Versus Pembrolizumab (MK-3475) Monotherapy for Programmed Cell Death 1 Ligand 1 (PD-L1) Positive Metastatic Non-Small Cell Lung Cancer (MK-7684A-003, KEYVIBE-003)," were posted on 2025-08-26 on clinicaltrials.gov.