The efficacy and safety of mirvetuximab soravtansine in FRα-positive, third-line and later, recurrent platinum-sensitive ovarian cancer: the single-arm phase II PICCOLO trial

Abstract

Antibody–drug conjugate; Folate receptor alpha; Platinum-sensitive ovarian cancer

Conjugado anticuerpo-fármaco; Receptor de folato alfa; Cáncer de ovario sensible al platino

Conjugat anticòs-fàrmac; Receptor de folat alfa; Càncer d'ovari sensible al platí

Background Mirvetuximab soravtansine-gynx (MIRV) is a first-in-class, folate receptor alpha (FRα)-targeting antibody–drug conjugate with United States Food and Drug Administration approval for FRα-positive platinum-resistant ovarian cancer. PICCOLO is a phase II, global, open-label, single-arm trial of MIRV as third-line or greater (≥3L) treatment in patients with FRα-positive (≥75% of cells with ≥2+ staining intensity) recurrent platinum-sensitive ovarian cancer (PSOC). Patients and methods Participants received MIRV (6 mg/kg adjusted ideal body weight every 3 weeks) until progressive disease (PD), unacceptable toxicity, withdrawal of consent, or death. Primary endpoint was investigator-assessed objective response rate (ORR). Key secondary endpoint was investigator-assessed duration of response (DOR). Additional endpoints included investigator-assessed progression-free survival (PFS), overall survival (OS), and safety. Analyses of subgroups by disease characteristics (e.g. platinum-free interval) and treatment history [e.g. prior bevacizumab and poly (adenosine diphosphate [ADP]-ribose) polymerase inhibitor (PARPi) treatment] were exploratory. Results Seventy-nine participants were enrolled and efficacy assessable. The primary endpoint was met; ORR was 51.9% [95% confidence interval (CI) 40.4% to 63.3%]. Median DOR was 8.25 months (95% CI 5.55-10.78 months) and median PFS was 6.93 months (95% CI 5.85-9.59 months). OS was not mature at data cut-off. ORR was 45.8% (95% CI 32.7% to 59.2%) in participants with PD while on/within 30 days of prior PARPi (n = 59) and 60.0% (95% CI 14.7% to 94.7%) in those without PD with prior PARPi (n = 5). No new safety signals occurred; most common treatment-emergent adverse events (TEAEs) were gastrointestinal, neurosensory, and resolvable ocular events. TEAEs led to discontinuation in 13 participants (16%) and death in 2 participants (3%). Conclusions MIRV as ≥3L treatment in heavily pretreated recurrent FRα-positive PSOC demonstrated notable efficacy and tolerable safety, including among those with prior PD on or within 30 days of PARPi (NCT05041257).

This work was supported by ImmunoGen, Inc. (no grant number). The sponsor designed, collected, analyzed, and interpreted the trial data in collaboration with the authors.