FDA Approval Sought for Mirvetuximab Soravtansine in FRα-High Platinum-Resistant Ovarian Cancer


An application for approval has been submitted to the FDA for mirvetuximab soravtansine to treat patients with folate receptor alpha-high platinum-resistant ovarian cancer.

A biologics license application (BLA) had been submitted to the FDA for mirvetuximab soravtansine monotherapy as a potential treatment option for patients with folate receptor alpha (FRα)-high platinum-resistant ovarian cancer who have been previously treated with 1 to 3 prior systemic treatments, according to an announcement by ImmunoGen, Inc.1

Data from the phase 3 SORAYA clinical trial (NCT04296890) support the BLA for single-agent mirvetuximab soravtansine, an antibody-drug conjugate. Topline data from the study recently showed that the agent achieved meaningful anti-tumor activity with consistent safety and favorable tolerability, meeting the study’s primary end point.2

"The BLA submission for mirvetuximab soravtansine is a key inflection point on our journey to delivering a safe and effective treatment option to patients with platinum-resistant ovarian cancer and moves us one step closer to transforming ImmunoGen into a fully-integrated oncology company," said Mark Enyedy, president and chief executive officer, ImmunoGen, in a press release. "Platinum-resistant ovarian cancer is an area with high unmet need, and we look forward to working with [the] FDA to secure mirvetuximab soravtansine’s first approval and bringing this novel therapy to patients as quickly as possible."

SORAYA is a phase 3, single-arm study has thus far enrolled 106 of 110 patients with platinum-resistant high-grade serous epithelial ovarian cancer, primary peritoneal, or fallopian tube cancer, whose tumors express a high-level of FRα. Patients in the study are being treated with mirvetuximab soravtansine monotherapy at 6 mg/kg adjusted by ideal body weight administered on day 1 of every 3-week cycle and assessed for the primary end point of objective response rate (ORR), as well as for secondary end points including duration of response (DOR), adverse events, progression-free survival (PFS), overall survival, and CA-125 response.3

The median number of prior lines of therapy was 3 in the 106 patients enrolled. Fifty-one percent of patients had 3 prior lines of therapy and 48% had 1 to 2 prior lines of therapy. All patients received prior bevacizumab (Avastin), and 48% of patients received a prior PARP inhibitor.2

As of the data cutoff date of November 16, 2021, mirvetuximab soravtansine demonstrated an ORR of 32.4% (95% CI, 23.6%-42.2%) in the overall efficacy patient population (n = 105). Of the 34 patients who responded to the antibody drug conjugate, 5 patients achieved a complete response (CR), and 29 patients experienced a partial response (PR). Additionally, 45.7% of patients have stable disease (SD), and 19.0% experienced disease progression. The median DOR was 6.9 months (95% CI, 5.6-8.1) with the agent, and the median PFS with mirvetuximab soravtansine was 4.3 months (95% CI, 3.7-5.1).

In the group of patients who had previously received 1 to 2 lines of treatment, mirvetuximab soravtansine achieved an ORR of 35.3% (95% CI, 22.4%-49.9%), with a 5.9-month median DOR (95% CI, 4.2-8.1). Among patients who received 3 prior lines of treatment, mirvetuximab soravtansine induced an ORR of 30.2% (95% CI, 18.3%-44.3%), with a median DOR of 7.0 months (n = 16; 95% CI, 3.5-not reached [NR]).

In subjects who previously received a PARP inhibitor, the ORR shown with mirvetuximab soravtansine was 38.0% (95% CI, 24.7%-52.8%), and the median DOR was 5.7 months (n = 19; 95% CI, 3.5-8.1). Those who were not previously exposed to a PARP inhibitor had an ORR of 27.5% (95% CI, 15.9%-41.7%) with the agent, and the median DOR was 5.9 months (n = 14; 95% CI, 3.0-NR).

Finally, the ORR as assessed by the blind independent review (BICR) committee was 31.6% (95% CI, 22.4%-41.9%) among 95 patients, which included a CR rate of 5.3% as well as a PR rate of 26.3%. A total of 55.8% of patients achieved SD, and 8.4% experienced disease progression. The BICR-assessed median DOR was 11.7 months (95% CI, 5.0-NR), and the BICR-assessed median PFS was 5.5 months (95% CI, 3.8-6.9).

Overall, mirvetuximab was well-tolerated and consistent with the known safety profile. Treatment-related adverse events (TRAEs) resulted in dose reductions in 19% of patients, dose delays in 32%, and discontinuations in 7%. The most common TRAEs observed were low-grade and generally reversible, including blurred vision, keratopathy, and nausea.


1. Immunogen submits biologics license application to the US Food and Drug Administration for mirvetuximab soravtansine in ovarian cancer. News release. ImmunoGen. March 29, 2022. Accessed March 29, 2022.

2. ImmunoGen Presents Full Results from Positive Pivotal SORAYA Trial of Mirvetuximab Soravtansine in Ovarian Cancer at SGO Annual Meeting. News Release. ImmunoGen, Inc. March 19, 2022. Accessed March 29, 2022.

3. Study of mirvetuximab soravtansine in platinum-resistant, advanced high-grade epithelial ovarian, primary peritoneal, or fallopian tube cancers with high folate receptor-alpha expression (SORAYA). Clinicaltrials.gov. Updated March 29, 2022. Accessed March 29, 2022. https://bit.ly/3LpemVL

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