360 Health-related quality of life in patients with FRα positive platinum-resistant ovarian cancer treated with mirvetuximab soravtansine vs. investigator’s choice chemotherapy: analysis from the phase 3 MIRASOL trial

Introduction/Background Mirvetuximab soravtansine-gynx (MIRV), an antibody-drug conjugate targeting folate receptor-alpha (FRα), is the first novel treatment to demonstrate a benefit in overall survival in platinum-resistant ovarian cancer (PROC) in a phase 3 trial. MIRASOL is the confirmatory, randomized, global phase 3 trial of MIRV vs standard-of-care chemotherapy in patients with PROC. Here we report quality of life (QoL) findings from the MIRASOL trial, measured using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 instrument. Methodology 453 patients with FRα positive PROC (Roche FOLR1–2.1 Assay) who received 1–3 prior lines of therapy were randomized 1:1 to MIRV 6 mg/kg, adjusted ideal body weight every 3 weeks or investigator's choice chemotherapy (ICC) paclitaxel, pegylated liposomal doxorubicin, or topotecan. Global health status (GHS), physical functioning (PF), role functioning (RF), and fatigue symptom (FS) subscales were collected. Responder analyses at week 8/9 were analyzed using the Cochran-Mantel-Haenszel (CMH) to test for differences between the MIRV arm and the IC Chemo arm. Change from baseline was analyzed with mixed model repeated measures. Results Across all subscales, a higher proportion of patients treated with MIRV vs ICC showed improvement at week 8/9 with statistically significant differences across arms in the GHS (22.9% vs 10.4%, p-value = 0.0023), RF (10.1% vs 3.9%, p-value=0.0386), and FS scales (14.3% vs 4.6%, p-value=0.0038). PF was (11.8% vs 5.8%, p-value= 0.0672). Change from baseline scores favored MIRV across all subscales, with statistically significant differences in all subscales at week 8/9, week 15/16, and week 24 (figure 1). Conclusion In the MIRASOL study, patients treated with MIRV maintained HRQoL while deterioration in HRQoL was observed in the ICC arm. The efficacy and safety of MIRV is supported by PRO data from the MIRASOL trial and position MIRV as a new standard of care for pts with FRα positive PROC. Disclosures N/A.