285 Patient-reported outcomes from the phase 3, randomized, double-blind, placebo-controlled ENGOT-Cx11/GOG 3047/KEYNOTE-A18 study of pembrolizumab plus concurrent chemoradiotherapy in patients with high-risk locally advanced cervical cancer

Introduction/Background We report prespecified patient-reported outcome (PRO) analyses from the phase 3 ENGOT-cx11/GOG 3047/KEYNOTE-A18 study (NCT04221945). Methodology Patients with high-risk locally advanced cervical cancer (LACC; FIGO 2014 stage IB2-IIB with node-positive disease or stage III-IVA) were randomized to 5 cycles of pembrolizumab 200 mg Q3W + CCRT (cisplatin 40 mg/m2 plus EBRT followed by brachytherapy) followed by 15 cycles of pembrolizumab 400 mg Q6W or 5 cycles of placebo Q3W + CCRT followed by 15 cycles of placebo Q6W. Changes from baseline to week 36 in QLQ-C30 global health status/quality of life (GHS/QoL) and physical functioning (PF) and QLQ-CX24 symptom-experience scale were secondary endpoints. Other PRO analyses were exploratory endpoints. PROs were classified as improved based on a ≥10-point change (QLQ-C30, QLQ-CX24) or ≥7-pt change (EQ-5D-5L). No alpha was assigned to PRO analyses. Results Of 1060 patients in the intent-to-treat population, 1008 were included in PRO analyses (pembrolizumab+CCRT, n=502; placebo+CCRT, n=506). In both arms, QLQ-C30 GHS/QoL and QLQ-C30 PF and EQ-5D-5L VAS scores decreased from baseline at weeks 3 and 6 but improved relative to baseline at week 12 and subsequent weeks. A similar proportion of patients had improved/stable scores for the QLQ-C30 GHS/QoL (75.7% vs. 75.3%), QLQ-C30 PF (76.5% vs. 76.5%), QLQ-CX24 symptom experience (84.7% vs. 85.1%) and EQ-5D-5L VAS (73.3% vs. 75.6%) in both arms. There were no clinically meaningful between-group differences in changes in PRO scores from baseline to week 36 for QLQ-C30 GHS/QoL, QLQ-C30 PF, QLQ-CX24 symptom experience, or EQ-5D-5L VAS (table 1). Conclusion Improvement in PFS with addition of pembrolizumab to CCRT in patients with high-risk LACC was accompanied by QoL changes similar to those in the placebo+CCRT group. These results support pembrolizumab+CCRT as a new standard of care for patients with high-risk LACC and support the positive benefit-risk profile of this combination. Disclosures Disclosures are provided via the ESGO COI Disclosure form.