Chemotherapy, particularly platinum-based combinations, remains central to ovarian cancer treatment. But tumors can differ in their biological and molecular features, and testing for those differences is increasingly helping guide treatment choices, especially when the disease returns and becomes resistant to platinum.
One target is folate receptor alpha, or FRα, a protein found in high amounts on some ovarian tumor cells. Brazil’s health regulator, Anvisa, approved mirvetuximab soravtansine in 2025 for eligible patients with FRα-expressing, platinum-resistant epithelial ovarian, fallopian tube or primary peritoneal cancer after one to three previous lines of treatment.
Mirvetuximab is an antibody-drug conjugate. Its antibody binds to FRα on tumor cells and delivers a cytotoxic drug, which interferes with cell division. Treatment requires specific monitoring, including for possible eye toxicity, and testing is needed to establish whether the tumor has sufficient FRα expression.
Anvisa approved another option in 2026: pembrolizumab for patients with platinum-resistant epithelial ovarian, fallopian tube or primary peritoneal cancer whose tumors express PD-L1, with a combined positive score of at least 1. It is given with paclitaxel, with or without bevacizumab, after one or two prior lines of systemic treatment. The approval was based on a study in which the combination reduced the risk of disease progression or death compared with treatment without pembrolizumab among patients with PD-L1 expression.
The article’s author, clinical oncologist Larissa Müller Gomes, notes that immunotherapy alone had not produced consistent results for most patients with ovarian cancer. The new indication uses a combination approach and, like mirvetuximab, depends on identifying a biomarker.
Tumor subtype and other molecular features can also affect treatment decisions. The article points to a 2025 US FDA approval of avutometinib with defactinib for a specific group: patients with recurrent low-grade serous ovarian cancer, a KRAS mutation and previous systemic treatment. It also cites BRCA alterations and homologous recombination deficiency as markers that have helped establish the use of PARP inhibitors in selected patients.
Gomes emphasizes that newer therapies do not replace chemotherapy or suit every patient. Decisions also take account of the disease stage, tumor type, previous treatments, response to platinum, overall clinical condition and molecular test results. As testing becomes more important, pathology, immunohistochemistry and molecular analyses can help determine which medicines may be appropriate for an individual tumor.
Sources: CNN Brasil.