Four decades in, ImmunoGen gets landmark green light in advanced ovarian cancer

After 41 years, ImmunoGen has scored its first approval for a solely owned drug. On Monday, the FDA signed off on Elahere to treat advanced ovarian cancer.

Elahere (mirvetuximab soravtansine) becomes the first FDA-approved antibody drug conjugate for platinum-resistant disease. It also is the first approval in eight years for advanced ovarian cancer.

Elahere works by supplying a targeted dose of chemotherapy directly to cancer cells. It's approved to treat patients with foliate-receptor alpha (Fra)-positive, platinum-resistant epithelial ovarian, fallopian tube or primary peritoneal cancer who have received one to three prior treatments.

Importantly, Elahere can be used regardless of prior treatment with Roche’s Avastin. The broad label opens the treatment up to approximately 5,200 patients in the U.S., the Waltham, Mass.-based company said.

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“We believe Elahere has the potential to displace single-agent chemotherapy as the new standard of care for patients with (Fra)-positive, platinum-resitant ovarian cancer,” Anna Berkenblit, ImmunoGen’s chief medical officer, said on a conference call.

Along with the approval, the FDA signed off on a Roche diagnostic to identify patients eligible for the new therapy. Ventana FOLR1 RxDx Assay is the first immunohistochemistry (IHC) companion diagnostic test to aid in identifying epithelial ovarian cancer patients for Elahere.

ImmunoGen has priced a 100 mg dose of Elahere at $6,220, CEO Mark Enyedy said on the call. Patients typically receive three to four vials in a cycle of treatment, leaving the cost between approximately $18,500 and $25,000. The company is ready to launch Elahere “within days,” Enyedy added.

“This is just the beginning of the next chapter for ImmunoGen,” he added.

The FDA approved the drug based on data from a trial of 106 patents which showed Elahere’s ability to shrink tumors. The drug achieved a 32% objective response rate (ORR), with five patients completely cleared of tumors. The ORR was a decided improvement on the 12% figure seen in an earlier trial of single-agent chemotherapy.

ImmunoGen also hopes to clear the use of Elahere plus Avastin in the platinum-resistant setting. If sanctioned, this would add an additional 1,800 FRa patients to the "market opportunity," Enyedy said.

After an ovarian cancer diagnosis of late-stage disease, patients typically undergo surgery, followed by platinum-based chemotherapy and then maintenance therapy. But most patients resist treatment.

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The accelerated blessing came two weeks before the agency's decision deadline on the medicine.