Mirvetuximab Soravtansine Combination Yields Encouraging Response Rates in Ovarian Cancer

Mirvetuximab soravtansine in combination with bevacizumab (Avastin) to treat patients with platinum-agnostic ovarian cancer demonstrated a confirmed 64% overall response rate (ORR), regardless of platinum status, according to a study presented at the 2020 ASCO Virtual Scientific Program.

More, the mirvetuximab soravtansine combination proved to be a good pairing with bevacizumab, as the adverse events (AEs) observed were manageable and consistent with the AE profiles of each agent.

“With a confirmed 64% ORR, the combination of [mirvetuximab soravtansine] with bevacizumab has promising activity in high [folate receptor alpha] recurrent ovarian cancer, regardless of platinum status, and is encouraging with respect to available therapies reported in similar populations,” study author Lucy Gilbert, MD, MSc, of McGill University Health Center, said in her presentation.

The ORR for the entire cohort of patients was 47%. More, in a subset analysis of patients with high folate receptor alpha expressing tumors, the ORR for those patients was 64%. Specifically, the platinum-resistant subset and the platinum-sensitive subset recorded an ORR of 59% and 69%, respectively.

Duration of response and progression-free survival data are immature due to the median follow-up of 5.5 months.

Overall, 60 patients were included in the analysis, with a median age of 60 years. Of that group, the primary cancer diagnosis was epithelial ovarian cancer (n = 41), fallopian tube cancer (n = 15), and primary peritoneal (n = 4).

“In this trial, [mirvetuximab soravtansine] was combined with bevacizumab for a broader segment of recurrent ovarian cancer patients, regardless of platinum status,” said Gilbert.

The primary objective of this research was to evaluate the safety and tolerability of the mirvetximab soravtansine combination in recurrent epithelial ovarian cancer, primary peritoneal cancer, and fallopian tube cancer.

Of the 60 patients analyzed, 55 out of 60 (92%) demonstrated tumor burden reduction, with a deeper and more durable tumor reduction found in high folate receptor alpha patients.

The most common AEs associated with the combination regimen were diarrhea (68%), blurred vision (63%), fatigue (58%), and nausea (55%), with most adverse events being low grade. Hypertension and myelosuppression were the most common grade 3 or 4 AEs, occurring in 12% and 10% of patients, respectively. Thirteen patients (22%) discontinued treatment with bevacizumab and/or mirvetximab soravtansine due to treatment-related AEs.

“The combination of mirvetximab soravtansine and bevacizumab may benefit an increasing population of recurrent ovarian cancer for whom a non-platinum based regimen would be appropriate,” explained Gilbert.

Reference:

Gilbert L, Oaknin A, Matulonis UA, et al. Mirvetuximab soravtansine, a folate receptor alpha (FRα)-targeting antibody-drug conjugate (ADC), in combination with bevacizumab in patients (pts) with platinum-agnostic ovarian cancer. Presented at: 2020 ASCO Virtual Scientific Program; May 29, 2020. Abstract 6004.