The Food and Drug Administration has approved a new drug for ovarian cancer in a decision that gives its developer, ImmunoGen, the first wholly owned, marketed medicine in its 41-year history.
The regulator’s decision late Monday makes the drug, known as Elahere, the first new treatment available for ovarian cancer in more than seven years. It’s also a conditional approval that ImmunoGen will have to maintain by confirming Elahere’s benefits in further testing. A study is currently underway and expected to produce results early next year.
In the meantime, Elahere, previously known as mirvetuximab soravtansine, can be used to treat ovarian cancer patients whose disease has progressed despite one to three rounds of chemotherapy. Those patients’ tumors must have high levels of a protein called folate receptor alpha. That protein is overexpressed in an estimated 35% to 40% of ovarian cancers, ImmunoGen said.
The accelerated approval was based on a single-arm study called SORAYA. In that trial, 32% of patients given ImmunoGen’s drug had a partial or complete response to treatment, and those responses lasted for an average of nearly seven months.
Regulators also included a “black box” warning about eye-related side effects, such as pain and visual impairment, that have been associated with Elahere in clinial testing. This warning “may limit the commercial potential of the drug,” SVB Securities analyst Jonathan Chang wrote in a Nov. 14 note to clients.
The “true rate” of folate receptor alpha-positive patients remains unknown, he added, making the drug’s commercial prospects uncertain.
The confirmatory trial, called MIRASOL, has enrolled 453 patients and randomized them to receive either Elahere or chemotherapy. The drug’s main goal is to hold tumors in check longer than chemotherapy. If Elahere fails, the FDA could order its withdrawal, although doing so has proven difficult in certain cases.
ImmunoGen was formed in 1981 and has dealt with a variety of ups and downs over the years. The company’s technology, a way of making cancer drugs known as antibody-drug conjugates, was used to develop the Roche breast cancer medicine Kadcyla, which regulators first approved in 2013. But its own drug development efforts have sputtered, and the company sold off rights to Kadcyla royalties for a total of $266 million in 2019.
Behind Elahere, ImmunoGen has an experimental drug in Phase 2 trials for a rare type of leukemia and two other treatments in earlier testing for solid tumors. It also has licensed its technology to Novartis and Bayer and sold a drug candidate to Debiopharm.