Trial results for the Phase 1 KEYVIBE-001 study (NCT02964013) investigating vibostolimab alone and in combination with pembrolizumab in advanced solid tumors were posted on ClinicalTrials.gov on 2025-10-14. The combination of vibostolimab, pembrolizumab, and chemotherapy achieved an overall response rate of 75.0% in participants with extensive-stage small cell lung cancer.
Background
The KEYVIBE-001 study, also known as "Study of Vibostolimab Alone and in Combination With Pembrolizumab in Advanced Solid Tumors (MK-7684-001)," investigated vibostolimab as monotherapy and in combination with pembrolizumab or pembrolizumab plus chemotherapy in adults with metastatic solid tumors.
Trial design
The KEYVIBE-001 study (NCT02964013) was a Phase 1 trial that enrolled 474 participants. The study investigated vibostolimab as monotherapy and in combination with pembrolizumab or pembrolizumab plus pemetrexed and carboplatin in adults with metastatic solid tumors. Part A of the study focused on dose escalation and confirmation to estimate the recommended Phase 2 dose for vibostolimab monotherapy or in combination with pembrolizumab, pemetrexed, and carboplatin.
Key results
The trial evaluated overall response rates (ORR) across various cohorts and pharmacokinetic parameters. Key findings included:
- In the vibostolimab dose escalation phase, the ORR for vibostolimab monotherapy was 0.0%, while the combination of vibostolimab + pembrolizumab showed an ORR of 7.1%.
- For participants with programmed death 1 (PD-1) refractory non-small cell lung cancer (NSCLC), vibostolimab monotherapy achieved an ORR of 2.4%, and vibostolimab + pembrolizumab achieved an ORR of 5.3%.
- In PD-1 naive NSCLC, the combination of vibostolimab + pembrolizumab demonstrated an ORR of 24.4%.
- Participants with extensive-stage small cell lung cancer (ES-SCLC) treated with vibostolimab + pembrolizumab + carboplatin or cisplatin + etoposide achieved an ORR of 75.0%.
- In PD-1 naive ovarian cancer, vibostolimab + pembrolizumab showed an ORR of 9.5%, and the pembrolizumab/vibostolimab coformulation showed an ORR of 7.5%.
- For PD-1 naive cervical cancer, two cohorts treated with vibostolimab + pembrolizumab showed ORRs of 14.6% and 23.1%, respectively.
- Pharmacokinetic analysis showed the geometric mean Area Under the Curve from time 0 to 21 days (AUC 0-21 Days) of plasma vibostolimab was 5.42 day*μg/mL for vibostolimab monotherapy and 8.19 day*μg/mL for vibostolimab + pembrolizumab.
What this means
The results from the Phase 1 KEYVIBE-001 study indicate that vibostolimab in combination with pembrolizumab, particularly when combined with chemotherapy, may offer clinical benefit in certain advanced solid tumors, most notably in extensive-stage small cell lung cancer where a substantial overall response rate of 75.0% was observed. While vibostolimab monotherapy showed limited activity, its combination with pembrolizumab demonstrated improved response rates across several tumor types, including PD-1 naive NSCLC, ovarian cancer, and cervical cancer. These early-phase findings support further investigation into these combination therapies.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT02964013, titled "Study of Vibostolimab Alone and in Combination With Pembrolizumab in Advanced Solid Tumors (MK-7684-001) ( KEYVIBE-001)," were posted on 2025-10-14 on clinicaltrials.gov.