ImmunoGen ELAHERE wins accelerated FDA approval for ovarian cancer

ImmunoGen, Inc. has announced that its platinum-resistant ovarian cancer drug ELAHERE (mirvetuximab soravtansine-gynx) has been granted FDA accelerated approval.

This first FDA antibody-drug conjugate (ADC)-approval for platinum-resistant ovarian cancer indication covers those patients who have undergone one to three prior systemic treatment regimens, regardless of prior Avastin use. Additionally, VENTANA FOLR1 (FOLR1-2.1) RxDx Assay – Roche’s immunohistochemistry (IHC) companion diagnostic for identifying ovarian patients eligible for ELAHERE – has been contemporaneously approved by the FDA.

The accelerated FDA approval – approved based on the primary endpoint of objective response rate (ORR) and the key secondary endpoint of duration of response (DOR) data from the pivotal SORAYA trial – means adult patients with folate receptor alpha (FRα)-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer, who have previously been treated with between one and three prior systemic treatment regimens can be treated with ELAHERE.

ELAHERE was evaluated in the pivotal SORAYA trial, a single-arm study in 106 patients with platinum-resistant ovarian cancer whose tumours expressed high levels of FRα (also known as Folate receptor 1 protein) and who had been treated with one to three prior systemic treatment regimens. At least one of these had to include Avastin (bevacizumab).

ELAHERE demonstrated an ORR by investigator of 31.7%, including five complete responses (CRs) The median DOR by investigator was 6.9 months. The drug’s safety has been evaluated from a pooled analysis of three studies among a total of 464 patients with (FRα)-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who received at least one 6mg/kg adjusted ideal body weight (AIBW) dose of ELAHERE, administered intravenously once every three weeks.

Continued approval of ImmunoGen’s first-in-class ADC directed against FRα – a cell-surface protein highly expressed in ovarian cancer – might be contingent upon verification and description of clinical benefit in a further confirmatory trial: MIRASOL, a randomised trial, is fully enrolled and top-line data is expected in early 2023.

Ovarian cancer is the eighth most common cancer worldwide and is the leading cause of death from gynaecological cancers in the US: approximately 20,000 patients are diagnosed annually in the US alone, and 13,000 patients will die from it. Between 35% to 40% of ovarian cancer patients express high levels of FRα (i.e. greater than or equal to 75% tumour cells staining with 2+ intensity). Testing is now available in the US through four centralised laboratories and is expected to expand to additional laboratories over time.

Chief of the division of gynaecologic oncology at the Dana-Farber Cancer Institute, professor of medicine at the Harvard Medical School, and SORAYA co-principal investigator, Dr Ursula Matulonis, said: “The approval of ELAHERE is significant for patients with (FRα)-positive platinum-resistant ovarian cancer, which is characterised by limited treatment options and poor outcomes.”

She continued: “ELAHERE’s impressive anti-tumour activity, durability of response, and overall tolerability observed in SORAYA demonstrate the benefit of this new therapeutic option […]”

Senior vice president and CMO at ImmunoGen, Dr Anna Berkenblit, said: “Platinum-resistant ovarian cancer is a notoriously challenging disease to treat. Given there have been no new therapies approved by the FDA for this indication since 2014, ELAHERE’s accelerated approval is a tremendous advance in the ovarian cancer treatment paradigm.”

ImmunoGen’s president and CEO, Mark Enyedy, said: “With an indication for use regardless of prior treatment with Avastin, we believe ELAHERE is positioned to become the new standard of care for patients with (FRα)-positive platinum-resistant ovarian cancer.”

Following the accelerated approval, ImmunoGen announced that the drug will be listed at $6,200 per vial and start shipping “in a matter of days”. Each patient will receive three to four vials per treatment cycle, totalling between $18,500 to $25,000 per cycle. Packaged with a black box warning of the potential damage ELAHERE can do to patients’ eyes, including vision impairment and pain, the news nonetheless saw a share price rise of nearly 8% to $6.20 before the bell.