USFDA grants full approval for Abbvie Elahere for certain ovarian cancer patients

"The full FDA approval of ELAHERE for eligible patients with ovarian cancer represents the culmination of years of work by the ImmunoGen team. ELAHERE is the first and only antibody-drug conjugate (ADC) approved in the U.S. for this difficult-to-treat malignancy," said Roopal Thakkar, M.D., senior vice president, chief medical officer, global therapeutics, AbbVie.

ELAHERE was first granted FDA accelerated approval in November 2022 and the conversion to full approval is based on data from the confirmatory Phase 3 MIRASOL trial. This trial compared ELAHERE to investigator's choice (IC) of chemotherapy in patients with platinum-resistant ovarian cancer (PROC) whose tumors express high levels of FRα and who have been treated with up to three prior therapies. The primary endpoint of MIRASOL was progression-free survival (PFS) by investigator assessment and key secondary endpoints included objective response rate (ORR) and overall survival (OS).

"As the first treatment to show a statistically significant overall survival benefit in patients with platinum-resistant ovarian cancer, ELAHERE provides an effective new option for patients with folate receptor alpha positive tumors. These patients previously had very limited options and ELAHERE changes that," said Kathleen Moore, deputy director and associate director of clinical research at the Stephenson Cancer Center of The University of Oklahoma and MIRASOL principal investigator.

MIRASOL is a randomized Phase 3 trial of ELAHERE versus investigator's choice (IC) of single-agent chemotherapy (weekly paclitaxel, pegylated liposomal doxorubicin, or topotecan). Eligibility criteria include patients with PROC whose tumors express high levels of FRα, using the Ventana FOLR1 Assay, and who have been treated with up to three prior regimens. The primary endpoint of this trial is progression-free survival (PFS) by investigator assessment. Key secondary endpoints include objective response rate (ORR) and overall survival (OS). The trial enrolled 453 patients. Patients were stratified by number of prior lines of therapy (14% had one prior line of therapy, 39% had two prior lines of therapy, and 47% had three prior lines of therapy) and by IC chemotherapy, with paclitaxel as the most commonly chosen (41%), followed by PLD (36%) and topotecan (23%). 62% of patients received prior bevacizumab; 55% received a prior PARP inhibitor.

Based on current results:

• OS hazard ratio (HR) was 0.67 (95% confidence interval [CI]: 0.50, 0.88; p=0.0046), representing a 33% reduction in risk of death in the ELAHERE arm compared to the IC chemotherapy arm.
• PFS HR was 0.65 (95% CI: 0.52, 0.81; p<0.0001), representing a 35% reduction in the risk of tumor or cancer progression in the ELAHERE arm compared to IC chemotherapy.
• ELAHERE showed overall fewer Grade 3+ adverse events and a lower rate of discontinuations due to adverse events when compared to the IC chemotherapy control group.

Ovarian cancer is the leading cause of death from gynecological cancers in the United States. Each year, approximately 20,000 patients are diagnosed. Most patients present with late-stage disease and will typically undergo surgery followed by platinum-based chemotherapy. Unfortunately, the majority of patients eventually develop platinum-resistant disease, which is difficult to treat. In this setting, standard of care single-agent chemotherapies are associated with low response rates, short durations of response, and significant toxicities.

ELAHERE (mirvetuximab soravtansine-gynx) is a first-in-class ADC comprising a folate receptor alpha-binding antibody, cleavable linker, and the maytansinoid payload DM4, a potent tubulin inhibitor designed to kill the targeted cancer cells. 

The Marketing Authorization Application (MAA) for ELAHERE in Europe has been accepted by the European Medicines Agency (EMA). Regulatory submissions for ELAHERE are also under review in multiple other countries.

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