PH3 Study of Mirvetuximab Soravtansine vs Investigator's Choice of Chemotherapy in Women With FRa+ Adv. EOC, Primary Peritoneal or Fallopian Tube Cancer

Patients will be randomized to either IMGN853 or Investigator's Choice chemotherapy.

Inclusion Criteria:

- Diagnosed with advanced epithelial ovarian cancer, primary peritoneal cancer or
fallopian tube cancer

- Folate receptor alpha positive tumor expression as defined in the protocol

- Patients must have platinum-resistant ovarian cancer, defined as progression within 6
months from completion of a minimum of four cycles of platinum-containing therapy.

- Patients must have received at least one but no more than three prior systemic
treatment regimens and for whom single-agent chemotherapy is appropriate as the next
line of treatment

- Patients must have at least one lesion that meets the definition of measurable disease
by RECIST 1.1

Exclusion Criteria:

- Diagnosis of clear cell or low grade ovarian cancer

- Patients with primary platinum-refractory disease

- Serious concurrent illness or clinically relevant active infection as defined in the
protocol

- Prior treatment with IMGN853

- Women who are pregnant or breast feeding