This study will enroll patients with persistent or recurrent FRα-positive uterine serous carcinoma (pure or mixed), Grade 3 endometrial adenocarcinoma, or carcinosarcoma with high grade serous or Grade 3 endometrioid components. All patients must have measurable disease. The primary objective of the study is to assess the activity of IMGN853 as measured by objective response rate (ORR). The secondary objectives are to assess the duration of overall survival (OS), progression-free survival (PFS) and durable disease control rate (DDCR), as well as the safety profile of IMGN853 in endometrial carcinoma patients. Exploratory/correlative objectives are to correlate ORR, PFS, and OS with the level of folate receptor α expression and explore use of circulating tumor (ct) DNA as a biomarker for disease response and compare its performance to cancer antigen 125 (CA-125). All enrolled patients will receive IMGN853 at a dose of 6 mg/kg administered intravenously once every 3 weeks until unacceptable toxicity or progression of disease requiring discontinuation of treatment.
The purpose of this study is to evaluate the activity and safety profile of mirvetuximab soravtansine (IMGN853) in patients with type II endometrial cancers that overexpress folate receptor alpha (FRα).