Aims
The ph3 Study 309/KEYNOTE-775 demonstrated statistically significant improvements in PFS, OS, and ORR with LEN+pembro vs TPC in pts with aEC. We report updated Study 309/KEYNOTE-775 analyses.
Methods
Pts with aEC and 1 prior platinum-based chemotherapy regimen (up to 2 if 1 given in neoadjuvant/adjuvant setting) were randomized to LEN 20mg orally QD + pembro 200mg IV Q3W or TPC (doxorubicin 60mg/m2 IV Q3W or paclitaxel 80mg/m2 IV QW [3 wks on; 1 wk off]). Randomization was stratified by mismatch repair (MMR) status; pts with proficient (p)MMR tumors were further stratified by ECOG PS, geographic region, and pelvic irradiation. We report final pre-specified OS, PFS and ORR (BICR per RECIST v1.1), and safety (data cutoff: March 1, 2022). Analyses are descriptive.
Results
827 Pts (pMMR, n=697; deficient MMR, n=130) were randomized to LEN+pembro (n=411) or TPC (n=416). Median follow-up was 18.7mo (LEN+pembro) and 12.2mo (TPC). Median PFS (months) remained longer with LEN+pembro vs TPC in pMMR aEC (6.7 vs 3.8; HR, 0.60 [95% CI 0.50-0.72]) and in all-comers (7.3 vs 3.8; HR, 0.56 [95% CI 0.48-0.66]). Median OS (months) remained longer with LEN+pembro vs TPC in pMMR aEC (18.0 vs 12.2; HR, 0.70 [95% CI 0.58-0.83]) and in all-comers (18.7 vs 11.9; HR, 0.65 [95% CI 0.55-0.77]), despite some pts in the TPC arm receiving subsequent LEN+pembro (pMMR, 10.0%; all-comers; 8.7%). ORR (95% CI) for LEN+pembro vs TPC was 32.4% (27.5-37.6) vs 15.1% (11.5-19.3) in pMMR pts and 33.8% (29.3-38.6) vs 14.7% (11.4-18.4) in all-comers. 90% Of pts with LEN+pembro and 74% of pts with TPC had grade ≥3 TEAEs.
Conclusions
LEN+pembro continued to demonstrate improved efficacy vs TPC in pts with aEC who received prior platinum therapy. Safety was generally consistent with the primary analysis.
Previously presented at ESMO 2022, FPN: 525MO, V. Makker et al. Reused with permission.