NEW YORK – The US Food and Drug Administration on Monday granted accelerated approval to ImmunoGen's Elahere (mirvetuximab soravtansine-gynx) for patients with folate receptor alpha (FRa)-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who have received up to three prior systemic treatments.
The FDA simultaneously approved Roche's Ventana FOLR1 (FOLR1-2.1) RxDx Assay as a companion diagnostic to identify FRa-positive patients eligible for Elahere. FRa-positive tumors are those that have FRa expression on at least 75 percent of tumor cells or 2+ staining on Roche's FLOR1 immunohistochemistry test. The assay is currently available from four labs in the US.
The agency granted accelerated approval to Elahere after reviewing data from the single-arm Phase III SORAYA trial. Among 106 patients, the objective response rate on Elahere by investigator assessment was 31.7 percent, including five complete responses. The median duration of response was 6.9 months. ImmunoGen used Roche's assay to select patients who received treatment in the trial.
Full approval of Elahere is contingent upon a confirmatory trial. Toward that end, ImmunoGen has fully enrolled the randomized, Phase III MIRASOL study, in which it will compare Elahere against investigator's choice of chemotherapy in previously treated, FRa-positive, platinum-resistant ovarian cancer patients. Top-line data from the MIRASOL trial are expected in early 2023, and the FDA has requested ImmunoGen submit preliminary objective response rate and duration of response data from both arms of the study.
"Platinum-resistant ovarian cancer is a notoriously challenging disease to treat. Given there have been no new therapies approved by FDA for this indication since 2014, Elahere's accelerated approval is a tremendous advance in the ovarian cancer treatment paradigm," ImmunoGen Chief Medical Officer Anna Berkenblit said in a statement.
Elahere, according to ImmunoGen, is a first-in-class antibody-drug conjugate that targets FRa and the first ADC to be approved for platinum-resistant ovarian cancer. According to ImmunoGen President and CEO Mark Enyedy, the drug has the potential to become the new standard of care for these difficult-to-treat patients, particularly since the FDA-approved indication is for previously treated patients regardless of whether they received Genentech's Avastin (bevacizumab).
ImmunoGen is also studying Elahere in patients with FRa-positive, platinum-sensitive epithelial ovarian, fallopian tube, or primary peritoneal cancer who have received two prior lines of therapy in the Phase II PICCOLO trial. The firm is also exploring the drug in combination with Avastin as a maintenance therapy in FRa-high ovarian cancer and in combination with chemo in FRa-low, -medium, and -high ovarian cancer patients.
Other FRa-targeted therapies under evaluation in ovarian cancer include Bristol Myers Squibb and Eisai's MORAb-202 and Sutro Biopharma's STRO-002.