One of the most frequent causes of death from cancer in females is epithelial cancer of the ovary. There is an urgent need to find better treatments, especially to aid those with advanced disease that is resistant to current standard of care options. Progress is underway as new antibody-drug conjugate therapy is emerging as an effective approach for helping certain patients with ovarian cancer.

While there has been a noted decline in ovarian cancer diagnoses and death since the nineties, it is still estimated that nearly 20,000 new cases will be diagnosed this year, and over 13,000 patients will not survive their illness. The prognosis for ovarian cancer patients is typically poor, as many cases involve high-grade serous carcinoma that is often diagnosed at a later stage of disease. In order to improve survival, cytoreductive surgery is recommended, which will usually be followed by platinum-based chemotherapy (commonly carboplatin or paclitaxel, often with the addition of bevacizumab). An unfortunate majority of patients experience ovarian cancer that returns after these treatments. Recurrence of ovarian cancer within six months is considered platinum-resistant, placing patients in an even more difficult-to-treat disease state as therapeutic options are very limited with high toxicity.

The FDA has granted fast-track approval to a first-in-class agent that is showing the potential to renovate the standard of care for platinum-resistant patients. The approval was for Elahere (mirvetuximab soravtansine-gynx), an injectable antibody-drug conjugate that is able to target folate receptor alpha (FRα), a protein that epithelial tumors tend to overexpress. The ability of mirvetuximab soravtansine to selectively target tumor tissue while leaving normal tissues unaffected is a valuable and much-desired quality in ovarian cancer treatment. The antibody portion of the conjugate binds to FRα, granting the drug entry to the cell it binds to. After the drug is inside the cell, its chemotherapy portion, DM4, activates, leading to cancer cell death. This precise targeting is the type of action researchers have been seeking in order to push past current ovarian cancer treatment limitations. The prior response rates for standard care measures were under 10%, but mirvetuximab soravtansine has demonstrated rates triple those, which is a strong and promising improvement.

The indication for Elahere is treatment of adults with FRα-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer, who have received one to three prior systemic treatment regimens. The prescribing information for the new approval also includes a boxed warning for ocular toxicity. This includes instances of visual impairment, keratopathy, dry eye, photophobia, eye pain, and uveitis. In order to identify patients who are eligible for treatment, an immunohistochemical diagnosis for detection of the folate receptor biomarker is necessary. Along with the Elahere approval, the FDA also endorsed the Ventana FOLR1 (FOLR-2.1) RxDx Assay, a first-ever companion diagnostic for the FOLR1 biomarker in patients with ovarian cancer.

Continued research and discovery are underway to develop deeper knowledge that will further define the role mirvetuximab soravtansine will play as a potential standard of care in cancer treatment. Stay informed about emergent drug information, including treatment options for gynecological cancers, by updating or registering your profile to receive email alerts and other critical drug information updates from PDR. You can also stay current by using the official PDR app, mobilePDR, available for free from your favorite app stores.