Is Mirvetuximab Soravtansine Active in Platinum-Resistant Ovarian Cancer?


Key Points

  • Mirvetuximab soravtansine produced response in 26% of patients with FRα-positive platinum-resistant ovarian cancer.
  • Response rate and progression-free survival were higher in patients with up to three prior lines of treatment.

Moore et al found that mirvetuximab soravtansine (also known as IMGN853)—an antibody-drug conjugate targeting folate receptor alpha (FRα)—is active in FRα-positive platinum-resistant ovarian cancer, according to a phase I expansion cohort study reported in the Journal of Clinical Oncology.

Study Details

In the study, 46 patients with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer received mirvetuximab soravtansine at 6.0 mg/kg (adjusted ideal body weight) once every 3 weeks. Patients had to be FRα-positive on immunohistochemistry, defined as ≥ 25% of tumor cells with ≥ 2+ staining intensity.

Response Rates and Adverse Events

Among all patients, the confirmed objective response rate was 26%, including a complete response in 1 patient and a partial response in 11 patients; the median progression-free survival was 4.8 months; and the median duration of response was 19.1 weeks. Among 23 patients with ≤ 3 prior lines of therapy, the objective response rate was 39%, the median progression-free survival was 6.7 months, and the median duration of response was 19.6 weeks.

The most common treatment-related adverse events of any grade were diarrhea (44%), blurred vision (41%), nausea (37%), and fatigue (30%). Grade 3 fatigue and grade 3 hypotension each occurred in 2 patients (4%), with no other grade 3 event occurring in > 1 patient.

The investigators concluded: “IMGN853 [mirvetuximab soravtansine] exhibited a manageable safety profile and was active in platinum-resistant ovarian cancer, with the strongest signals of efficacy observed in less heavily pretreated individuals. On the basis of these findings, the dose, schedule, and target population were identified for a phase III trial of IMGN853 monotherapy in patients with platinum-resistant disease.”

The study was supported by ImmunoGen.

Kathleen N. Moore, MD, of Stephenson Cancer Center, The University of Oklahoma, is the corresponding author of the Journal of Clinical Oncology article.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.