164 Phase 3 recurrent/metastatic cervical carcinoma trial: subgroup efficacy analysis of cemiplimab versus individual investigator’s choice chemotherapy

Introduction/Background* There is no standard of care regimen in the second-line setting for women with recurrent/metastatic (R/M) cervical carcinoma. Cemiplimab was recently shown to significantly improve overall survival (OS) compared with investigator’s choice (IC) chemotherapy in patients with R/M cervical cancer after first-line platinum-based chemotherapy (NCT03257267; ESMO-VP-2021). We present a pre-planned exploratory subgroup analysis comparing cemiplimab to individual IC chemotherapy options. Methodology EMPOWER-Cervical 1/GOG-3016/ENGOT-cx9 is an open-label, randomised (1:1), multi-centre, Phase 3 clinical trial of anti-programmed cell death (PD)-1 cemiplimab vs IC single agent chemotherapy in R/M cervical cancer that has progressed after first-line platinum-based treatment. The selection of single-agent chemotherapy by the investigator (gemcitabine, pemetrexed, vinorelbine, topotecan or irinotecan) was not protocol-defined, but the regimen had to be chosen prior to randomisation. Adult females (age ≥18 years) were enrolled regardless of PD-ligand 1 expression and received cemiplimab 350 mg intravenously every 3 weeks or IC chemotherapy for up to 96 weeks; and were stratified by histology (squamous cell carcinoma/adenocarcinoma or adenosquamous), geographic region (North America/Asia/rest of world), prior bevacizumab, and ECOG performance status (0/1). Primary endpoint was OS. Additional endpoints included progression-free survival (PFS), objective response rate (ORR), duration of response, quality of life and safety. Data cutoff was 4 January 2021. Result(s)* A total of 608 patients were randomised: 304 to cemiplimab and 304 to IC chemotherapy (gemcitabine, n=121; premetrexed, n=111; vinorelbine, n=32; topotecan, n=21; irinotecan, n=19) across geographic regions and histologies. Median duration of study follow-up (range) was 4.8 months (0.0–25.9) for the overall population. At second interim analysis, the trial was stopped early for efficacy. OS, PFS and ORR (table 1) demonstrated improvements with cemiplimab vs each IC chemotherapy treatment similar to those observed with cemiplimab vs pooled IC chemotherapy. Conclusion* Improvements in OS, PFS and ORR with cemiplimab trended consistently with the results for the overall population regardless of IC chemotherapy drug.