ImmunoGen Ovarian Cancer Drug Reaches BLA Milestone
Massachusetts-based ImmunoGen announced that it has submitted a biologics license application (BLA) to the U.S. Food and Drug Administration for mirvetuximab soravtansine to treat ovarian cancer. The BLA is one of several positive milestones ImmunoGen, a clinical-stage biotechnology company focused on developing antibody-drug conjugate (ADC) therapeutics for cancer, has reached in its ovarian cancer research.
Mirvetuximab soravtansine (IMGN853) is a first-in-class ADC. It uses a folate receptor alpha-binding antibody to bind to cancer cells. It then delivers maytansinoid payload DM4, an agent that targets tubulin proteins and destroys them, killing the cancer.
ImmunoGen has been working on mirvetuximab soravtansine for nearly seven years. The FDA granted the drug Orphan Drug Designation for ovarian cancer in April 2015. In June 2018, the drug received Fast Track Designation from the FDA specifically for ovarian cancer patients who were FRα-positive and whose cancer was resistant to platinum chemotherapy.
Based on those designations, ImmunoGen began testing mirvetuximab soravtansine in clinical trials. In December 2019, the company announced it would begin a series of trials called SORAYA to test the drug as a monotherapy for platinum-resistant ovarian cancer with tumors that express high levels of FRα. The study involved 106 patients who had been treated with at least one but no more than three rounds of previous chemotherapy regimens.
The trials went well. When ImmunoGen announced top-line results from the Phase III SORAYA trial in November 2021, the primary endpoint - confirmed objective response rate - was met at 32.4%. The drug was also well-tolerated among patients. Even better, a secondary endpoint of duration of response was 5.9 months.
Positive results in hand, ImmunoGen presented the complete study data at the Society of Gynecologic Oncology 2022 Annual Meeting earlier this month and has now submitted the BLA application.
“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,” Mark Enyedy, president and CEO at ImmunoGen, said. “Platinum-resistant ovarian cancer is an area with high unmet need, and we look forward to working with FDA to secure mirvetuximab soravtansine’s first approval and bringing this novel therapy to patients as quickly as possible.”
Now that the BLA is submitted, the FDA has 60 days to respond as it was filed under an accelerated approval pathway, an option designed for drugs that treat serious conditions and have high unmet needs.
In the meantime, ImmunoGen is enrolling patients in confirmatory MIRASOL clinical trials. These studies will generate the randomized data needed for the FDA to grant full approval to the drug. ImmunoGen expects those results to be available in Q3 2022.
If mirvetuximab soravtansine were to be approved, it would be a boon not just for ImmunoGen but also for expanding ADC drugs. Antibody-drug conjugate, a type of immunotherapy, is a market expected to top $20.01 billion by 2028. Despite the large market, only 12 ADC drugs have ever been approved by the FDA.
In the ovarian cancer space particularly, ImmunoGen has competition. Last week, Zai Lab, a China-based biopharma company, announced positive data from its Phase III PRIME clinical study on Zejula (niraparib) for ovarian cancer. Zejula helped extend patients’ progression-free survival (PFS) rates from 8.3 months with a placebo to 24.8 months.