The U.S. Food and Drug Administration (FDA) approved Roche’s VENTANA FOLR1 (FOLR1-2.1) RxDx Assay, an immunohistochemistry (IHC) companion diagnostic test to aid in identifying epithelial ovarian cancer (EOC) patients who are eligible for targeted treatment with ELAHERE (mirvetuximab soravtansine-gynx).

ELAHERE is an antibody-drug conjugate (ADC) therapy developed by ImmunoGen, Inc., approved under FDA’s Accelerated Approval program for the treatment of FRɑ-positive platinum-resistant ovarian cancer.

Folate receptor 1 protein (FOLR1), also known as folate receptor alpha (FRɑ), is expressed at some level in approximately 90% of ovarian carcinomas and serves as a predictive biomarker for FOLR1-targeted therapy for EOC patients. (1,2) The new test informs clinicians about the likelihood of potential patient benefit from FOLR1 therapy, (3,4) advancing Roche’s commitment to personalized healthcare through innovative solutions that help fit the treatment to the individual.

“We’re proud to expand our women’s health and oncology portfolios through the addition of the first companion diagnostic IHC test for ovarian cancer,” says Jill German, head of pathology lab at Roche Diagnostics. “This test will enable clinicians to make more informed treatment decisions for patients with ovarian cancer by quickly determining whether they qualify for ELAHERE therapy, potentially improving their outcomes.”

The approval is based on the results of the SORAYA clinical study.(4) In the study, approximately 35% of ovarian cancer patients expressed high levels of FRα (defined as ≥ 75% viable tumor cells with membrane staining at moderate and/or strong intensity levels) and were considered FRα-positive by the VENTANA FOLR1 (FOLR1-2.1) RxDx Assay. Of the FRα-positive patients, about 32% demonstrated a partial or complete response to ELAHERE therapy.(5)

Ovarian cancer is the eighth most common cancer in women worldwide and patients often have advanced disease when diagnosed.(6) Despite improvements in primary therapy, mortality rates remain high, and 80% percent of patients with advanced EOC will have their disease recur.(7,8) The five-year relative survival rate for all stages of invasive EOC is 49%.(9)


  1. Scaranti, M., Cojocaru, E., Banerjee, S. et al. Exploiting the folate receptor α in oncology. Nat Rev Clin Oncol 17, 349–359 (2020).
  2. Hilgenbrink A., Low P. Folate receptor-mediated drug targeting: From Therapeutics to diagnostics. Journal of Pharmaceutical Sciences. 2005;94(10): 2135-2146.
  3. James, R., Admire, B., Sisseron, T et al. 1125P Analytical assessment of a diagnostic immunohistochemical assay for the detection of folate receptor-ɑ in epithelial ovarian cancers. 2021; Annals of Oncology, Volume 32, S921 – S922.
  4. Roche. VENTANA FOLR1 (FOLR-2.1) RxDx Assay. US Package Insert. 2022.
  5. Matulonis UA, et al. Abstract LB4. Presented at Society of Gynecologic Oncology 2022 Annual Meeting on Women’s Cancer. March 18-21, 2022.
  6. American Cancer Society, “About Ovarian Cancer.”,  accessed 15 July 2022. URL
  7. du Bois A, Herrstedt J, Hardy-Bessard AC, et al. Phase III trial of carboplatin plus paclitaxel with or without gemcitabine in first-line treatment of epithelial ovarian cancer. Journal of Clinical Oncology Clin Oncol. 2010;28(27):4162–4169.
  8. Ferlay J, Ervik M, Lam F, Colombet M, Mery L, Piñeros M, Znaor A, Soerjomataram I, Bray F (2020). Global Cancer Observatory: Cancer Today. Lyon, France: International Agency for Research on Cancer. Available from:, accessed [15 July 2022].
  9. American Cancer Society, “About Ovarian Cancer.”,  accessed 15 July 2022. URL