Priority Review Granted with PDUFA Date of April 5, 2024

WALTHAM, MA, USA I December 5, 2023 IImmunoGen, Inc. (Nasdaq: IMGN), a leader in the expanding field of antibody-drug conjugates (ADCs) for the treatment of cancer, today announced that the US Food and Drug Administration (FDA) has filed the supplemental Biologics License Application (sBLA) supporting the conversion of the accelerated approval of ELAHERE® (mirvetuximab soravtansine-gynx) for the treatment of patients with folate receptor alpha (FRα)-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who have received one to three prior systemic treatment regimens to full approval. The application has been granted Priority Review designation with a Prescription Drug User Fee Act (PDUFA) action date of April 5, 2024.

“With the FDA’s filing of our sBLA, we are one step closer to securing full approval of ELAHERE in the US and establishing this novel ADC as the standard of care in FRα-positive platinum-resistant ovarian cancer,” said Michael Vasconcelles, MD, ImmunoGen’s Executive Vice President, Research, Development, and Medical Affairs. “This regulatory milestone, achieved just over one year after ELAHERE’s accelerated approval, underscores the significance of the confirmatory MIRASOL data and the broader data set seen to date with ELAHERE, as well as the urgency with which our teams worked to bring this potentially practice-changing therapy to eligible patients in need. We look forward to collaborating closely with the FDA throughout the review process.”

The confirmatory Phase 3 MIRASOL trial of ELAHERE in platinum-resistant ovarian cancer forms the basis of the sBLA. Top-line data from the MIRASOL trial were disclosed in May 2023 and presented as a late-breaking abstract at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting. In the MIRASOL trial, ELAHERE demonstrated statistically significant and clinically meaningful improvements in progression-free survival, objective response rate, and overall survival compared to investigator’s choice (IC) of single-agent chemotherapy. ELAHERE demonstrated a tolerable safety profile compared to IC chemotherapy, consisting predominantly of low-grade ocular and gastrointestinal events.

ELAHERE was granted accelerated approval by the FDA in November 2022 based on data from the pivotal SORAYA trial. A Marketing Authorization Application for ELAHERE in Europe has been accepted by the European Medicines Agency and a New Drug Application in China has been accepted by the National Medical Products Administration of China.


Ovarian cancer is the leading cause of death from gynecological cancers in the US. Each year, roughly 20,000 patients are diagnosed, and 13,000 patients will die. 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.


ImmunoGen is developing the next generation of antibody-drug conjugates (ADCs) to improve outcomes for cancer patients. By generating targeted therapies with enhanced anti-tumor activity and favorable tolerability profiles, we aim to disrupt the progression of cancer and offer our patients more good days. We call this our commitment to TARGET A BETTER NOW™.

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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.

ELAHERE is indicated for the treatment of adult patients with folate receptor-alpha (FRα) positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer, who have received one to three prior systemic treatment regimens. Select patients for therapy based on an FDA-approved test.

This indication is approved under accelerated approval based on tumor response rate and durability of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.

Eye problems are common with ELAHERE and can be severe. ELAHERE also can cause severe or life-threatening inflammation of the lungs that may lead to death and patients may develop nerve problems called peripheral neuropathy during treatment.

Please see full Prescribing Information, including Boxed Warning for ELAHERE.

SOURCE: ImmunoGen