TEST:

VENTANA FOLR1 RxDx Assay

Recently, the FDA approved mirvetuximab soravtansine for platinum-resistant ovarian carcinoma with FOLR1 overexpression, typically high-grade serous carcinoma... To our knowledge, this is the largest study to date of FOLR1 expression in USC. Nearly 1 in 5 USC patients are FOLR1+, independent of HER2 status. Further research testing the efficacy of FOLR1-targeted therapy in USC is needed, as approval could potentially double the proportion of patients with available targeted therapies.

Our results showed overexpression of FOLR1 and TROP2 in a significant proportion of high-grade EC, suggesting that targeted therapy against these markers may be a novel option for patients with EC. FOLR1 and HER2 positivity appeared mutually exclusive, while co-expression of FOLR1-TROP2 and HER2-TROP2 was also infrequent, observed in <5% of all tumors.

Introduction: Mirvetuximab soravtansine (MIRV) is an anti-folate receptor alpha (FOLR1)-drug conjugate... 41 cervical squamous cell carcinoma (SCC), 35 endocervical adenocarcinoma, 21 uterine serous carcinoma, 14 uterine carcinosarcoma, and 48 ovarian clear cell carcinoma (OCCC) cases were represented in the TMAs and stained with FOLR1 (see Figure 1). 0% of cervical SCC, 0% of endocervical adenocarcinoma, 14% of uterine serous carcinoma, 0% of uterine carcinosarcoma, and 0% of OCCC cases met current FOLR1 positivity criteria (PS2 ≥ 75%) (see Table 1). Figure 1: Examples of H&E and FOLR1 staining in endocervical adenocarcinoma (A-B), uterine serous carcinoma (C-D), and ovarian clear cell carcinoma (E- F) Table 1: FOLR1 PS2 scores of different tumor types Conclusion/Implications: Variable FOLR1 expression was seen in different gynecologic tumor types.

Antitumor activity has been observed at well tolerated dose levels. Dose escalation continues.

Background: Biomarker driven therapies are increasingly being used for gynecologic cancers, with mirvetuximab soravtansine, a Folate Receptor alpha (FRa) targeting antibody drug conjugate (ADC) being a recent FDA approved agent for patients with FRa positive PROC... Based on this analysis of a limited sample size, there does not appear to be an association between FRa and NaPi2b expression, with the majority of NaPi2b positive samples not being FRa positive. Additionally, general NaPi2b prevalence and the correlation of expression between RNA and IHC suggest that NaPi2b may be a rational biomarker to integrate in RNA tumor panel testing. This research underscores the importance of early, comprehensive testing of all relevant biomarkers to guide therapy selection, and suggests that additional research is needed to evaluate the potential association between FRa and NaPi2b expression via IHC.

By testing for FRα expression, you can help identify 35% of patients with EOC that may benefit from a promising FRα targeted therapy; ELAHERETM (mirvetuximab soravtansine). This comprehensive webcast aims to support pathologists with clinical training to better understand FRα biology and scoring of this novel IHC marker for EOC samples. Info Title: FRa Biology and FOLR1 IHC Scoring

"NeoGenomics, Inc...today launched a novel biomarker testing program for patients with epithelial ovarian cancer, including primary peritoneal or fallopian tube cancers (EOC).Through the FR-ASSIST™ program, sponsored by ImmunoGen, Inc...EOC patients will have access to the FOLR1 IHC CDx test (VENTANA FOLR1 RxDx Assay) performed by NeoGenomics to measure the expression of a protein called folate receptor alpha (FRα)...The new testing program is sponsored entirely by ImmunoGen and provides eligible EOC patients with FRα-expression testing through NeoGenomics at no cost, regardless of insurance coverage or test results."

"Roche...announced US Food and Drug Administration (FDA) approval of the VENTANA FOLR1 (FOLR1-2.1) RxDx Assay, the first 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)....Developed as a predictive biomarker, the VENTANA FOLR1 (FOLR1-2.1) RxDx Assay detects the folate receptor 1 protein (FOLR1 or FRɑ), which is over-expressed in most ovarian cancers. The new test identifies ovarian cancer patients eligible for targeted treatment with ELAHERE....The approval is based on the results of the SORAYA clinical study."