NEW YORK – ImmunoGen on Thursday said it will include positive data from two subset analyses in US and European regulatory applications seeking approval for Elahere (mirvetuximab soravtansine-gynx) as a treatment for certain patients with folate receptor alpha (FRα)-positive ovarian cancer.
According to the Waltham, Massachusetts-based firm, data from two subset analyses within the Phase III MIRASOL clinical trial showed better progression-free survival, objective response rate, and overall survival across subgroups of patients with platinum-resistant, FRα-positive ovarian cancer on Elahere compared to chemotherapy. Researchers found that, as seen in the overall population in MIRASOL, Elahere-treated patients fared better regardless of how many lines of therapy they had received and regardless of whether one of those prior lines of therapy included a PARP inhibitor.
Among patients who had previously received PARP inhibitors, 45 percent had an objective response and seven had a complete response on Elahere. Seventeen percent had an objective response on chemotherapy, on the other hand, and none experienced a complete response.
Among patients who had not received PARP inhibitors, the objective response rate was 40 percent on Elahere with five experiencing a complete response. In comparison, the objective response rate was 14 percent for those receiving chemotherapy, and none had a complete response. Progression-free survival and overall survival rates were also better for patients receiving Elahere versus chemotherapy regardless of prior PARP inhibitor status.
Patients who received one or two prior lines of therapy had a 46 percent objective response rate on Elahere versus 15 percent on chemotherapy, and there were 10 complete responses versus no complete responses, respectively, in these treatment arms. Among patients who received three prior lines of therapy, the overall response rate with Elahere was 38 percent versus 18 percent with chemo. Outcomes across progression-free survival and overall survival were likewise improved with Elahere versus chemo in both the second- or third-line treatment setting and the fourth-line treatment setting.
"The benefit seen with Elahere in patients treated with a prior PARP inhibitor is particularly encouraging, as it has been shown that PARP inhibitors have a potential negative impact on the efficacy of subsequent chemotherapies," Toon Van Gorp, a professor of gynecologic oncology at the University of Leuven and lead author of the MIRASOL trial subanalysis abstract presented at the European Society of Gynecological Oncology annual congress in Istanbul on Thursday, said in a statement. "These new data … further position ELAHERE to become the new standard of care for patients with FRα-positive platinum-resistant ovarian cancer."
According to Michael Vasconcelles, executive VP of R&D and medical affairs at ImmunoGen, the firm is planning to submit a marketing authorization request and a supplemental biologics licensing application to the European Medicines Agency and the US Food and Drug Administration, respectively, before year-end.
In 2022, Elahere netted accelerated approval from the FDA as a treatment for patients with FRα-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who have previously received one to three prior lines of therapy. ImmunoGen is seeking to convert the accelerated approval to a full approval based on the Phase III MIRASOL results and to net European approval in this setting, as well.