AbbVie has announced that late-breaking results from the phase 2 IMGN853-0420 trial.
The study evaluated the potential efficacy and safety of mirvetuximab soravtansine-gynx, a first-in-class antibody-drug conjugate (ADC), in combination with carboplatin followed by maintenance of mirvetuximab soravtansine-gynx monotherapy, in patients with folate receptor alpha (FRα)-expressing, recurrent platinum‑sensitive ovarian cancer (PSOC).
The multicenter, open-label study enrolled 125 patients with FRα‑positive, measurable disease who had received one prior platinum‑based chemotherapy regimen. Participants received mirvetuximab soravtansine-gynx plus carboplatin every three weeks for six to eight cycles, followed by single-agent mirvetuximab soravtansine-gynx as a continuation therapy. Nearly half of patients had prior exposure to a polymerase inhibitor (PARPi), a patient population who may experience reduced responses to subsequent platinum-based chemotherapy.
The primary endpoint of the study was a confirmed objective response rate (ORR) in the ≥50% FRα subgroup after six cycles of combination therapy. Key secondary endpoint was ORR after six cycles in the overall population (FRα ≥25%) and additional secondary endpoints included duration of response (DoR), progression-free survival (PFS) and overall survival (OS).
Key highlights from the late-breaking oral presentation include:
- Response rates across combination regimen: By the end of the induction phase, confirmed ORR was 62.7% (95% CI, 52.6–72.1) in the FRα ≥50% subgroup and 62.4% (95% CI, 53.3–70.9) in the overall population. 81% of patients (101/125) showed no disease progression and continued treatment with single-agent mirvetuximab soravtansine. Median DoR was 11.2 months across the overall population.
- Additional responses with continuation monotherapy: Among patients who were on the combination and transitioned to mirvetuximab soravtansine-gynx monotherapy, ORR was 68% (59.1–76.1) across the overall population.
- Responses in patients with prior exposure to polymerase inhibitor (PARPi): In nearly half of patients (49%) in the overall population (FRα ≥25%) who had prior PARPi exposure, ORR was 63.9% (50.6–75.8).
- Safety data: The safety profile of mirvetuximab soravtansine-gynx was consistent with findings from previous studies. The most common treatment-related adverse events (TRAEs) with mirvetuximab soravtansine-gynx plus carboplatin followed by a continuation of mirvetuximab-soravtansine-gynx alone were low‑grade ocular events, including corneal changes that were reversible in over 90% of patients. The most common grade ≥3 TRAEs (>5%) were neutropenia (15%), blurred vision (10%), thrombocytopenia (10%), cataract (6%), dry eye (5%), diarrhoea (5%) and peripheral sensory neuropathy (5%).
The data is being presented during the Rapid-Fire Oral III: Translational and ADC session on Sunday, April 12 at 12:32 PM ET.
Use of mirvetuximab soravtansine-gynx plus carboplatin followed by mirvetuximab soravtansine-gynx continuation in FRα-expressing recurrent PSOC is not approved in the US or in the EU or in any other territory. The safety and efficacy of mirvetuximab soravtansine-gynx for use as a combination therapy in PSOC have not been established.
