KEY TAKEAWAYS
- The KEYVIBE-005 phase II ongoing trial aimed to assess the comparative safety and efficacy of vibo/pembro vs pembro alone in pts with PD-L1+ CC.
- The primary endpoint were PFS and ORR.
- Vibo/Pembro did not outperform pembro in PD-L1+ CC; safety consistent with anti-TIGIT trials.
Vibostolimab (vibo), an anti-TIGIT therapy, in combination with pembrolizumab (pembro), has demonstrated promising efficacy in Cervical Cancer (CC). This trial specifically assessed the co-formulated vibo/pembro regimen in patients (pts) with priorly treated CC.
Christophe Le Tourneau and the team aimed to determine the efficacy of vibo/pembro in previously treated, anti-PD-[L]1 naive, unresectable/metastatic CC by PD-L1 status, based on the evaluation of progression-free-survival (PFS) and objective response rate (ORR).
Researchers enrolled adults ≥18 years with previously treated, anti-PD-L1 naive, unresectable, or metastatic CC. The pts were stratified by PD-L1 status into cohorts A1 (CPS ≥1) or A2 (CPS <1).
Cohort A1 was randomized 1:1 to receive co-formulated vibo 200 mg / pembro 200 mg or pembro 200 mg Q3W, while A2 received co-formulated vibo 200 mg / pembro 200 mg Q3W. The primary endpoints were PFS and ORR per RECIST 1.1 by BICR (A1) and INV (A2), with the secondary endpoints being duration of response (DOR) (RECIST 1.1, BICR for A1, INV for A2), overall-survival (OS), and safety. Data cutoff was October 24, 2023.
The results revealed that the data cut-off, cohort A1 included 169 pts: 85 received vibo/pembro and 84 received pembro alone, with median follow-up durations of 18.2 months and 15.7 months for cohorts A1 and A2, respectively. In cohort A1, vibo/pembro showed a 20% ORR compared to 15.5% with pembro alone (P=0.2215); cohort A2 had a 16.1% ORR. Median PFS was 2.2 months with vibo/pembro vs. 2.1 months with pembro alone in cohort A1 (HR=0.99, P=0.4787); cohort A2 also had a median PFS of 2.2 months.
Drug-related adverse events (AEs) occurred in 75% of pts with vibo/pembro and 58% with pembro in cohort A1, and in 77% of cohort A2. Grade ≥3 drug-related AEs were seen in 18% of vibo/pembro pts, 12% of pembro pts in cohort A1, and 29% in cohort A2. One patient in cohort A1 treated with vibo/pembro died from septic shock due to a drug-related AE. Immune-mediated AEs affected 35% of vibo/pembro pts, 31% of pembro pts in cohort A1, and 39% of cohort A2.
After comparing the vibo/pembro and pembro alone across different CPS groups, findings revealed similar overall response rates (ORR) among CPS≥1: 20.0% for vibo/pembro and 15.5% for pembro, with a 16.1% ORR for vibo/pembro in CPS<1. Complete responses (CR) were observed in 7.1% of pts across all groups, with partial responses (PR) in 12.9% for vibo/pembro CPS≥1, 8.3% for pembro CPS≥1, and 16.1% for vibo/pembro CPS<1. Median DOR was notable at 10.9 months for vibo/pembro CPS≥1 and 10.8 months for vibo/pembro CPS<1 vs non-reached (NR) for pembro CPS≥1.
The median PFS was consistent across groups, approximately 2.2 months, with similar 12-month PFS rates ranging from 16.8% to 19.8%. OS favored vibo/pembro CPS<1, with a median of 12.8 months and a 12-month OS rate of 50.6%, compared to approximately 10.2-10.3 months and 42.1-48.2% for the other groups. These results suggest promising outcomes with vibo/pembro, particularly in CPS<1 populations, warranting further investigation.
The study concluded that co-formulated vibo/pembro did not surpass pembro in efficacy for previously treated PD-L1+ CC; safety findings were consistent with other anti-TIGIT trials.
The trial was sponsored by Merck Sharp & Dohme LLC.
Source: https://cslide.ctimeetingtech.com/gynae24hybrid/attendee/confcal/show/session/21
Clinical Trial: https://clinicaltrials.gov/study/NCT05007106
Tourneau C. L., (2024). “Association of biomarkers with response to coformulated vibostolimab/pembrolizumab (vibo/pembro) in metastatic cervical cancer (CC): Exploratory analysis from the phase II KEYVIBE-005 study.” Presented at ESMO-GC 2024. (abstract 21O)
