A Phase 1b/2 Study to Evaluate the Safety, Tolerability and Pharmacokinetics of Mirvetuximab Soravtansine (IMGN853) in Combination with Bevacizumab, Carboplatin, Pegylated Liposomal Doxorubicin, Pembrolizumab, or Bevacizumab + Carboplatin, in Adults with Folate Receptor Alpha Positive Advanced Epithelial Ovarian Cancer, Primary Peritoneal Cancer, or Fallopian Tube Cancer

This study comprises a Dose Escalation phase followed by a Dose Expansion phase. Dose
Escalation part of the study will assess the safety and tolerability and determine the
maximum tolerated dose (MTD) as the recommended Phase 2 (RP2D) dose for each regimen.
Participants will be assigned to one of the 4 regimens in Dose Escalation phase: Regimen A:
mirvetuximab soravtansine administered with bevacizumab; Regimen B: mirvetuximab soravtansine
administered with carboplatin; Regimen C: mirvetuximab soravtansine administered with
pegylated liposomal doxorubicin; or Regimen D: mirvetuximab soravtansine administered with
pembrolizumab. Dose Expansion of the study will further assess safety, tolerability and
preliminary anti-tumor activity of mirvetuximab soravtansine. A Dose Expansion phase is
planned for Regimen A and Regimen D and will open pending Sponsor decision; participants
enrolled in the Dose Expansion phase will receive study treatment at the MTD or RP2D
determined during Dose Escalation. For Regimen A, participants in the Dose Expansion phase
may be enrolled according to prior exposure to bevacizumab into 3 Dose Expansion Cohorts as
follows: 1) Dose Expansion Cohort 1: bevacizumab naïve; 2) Dose Expansion Cohort 2:
bevacizumab pretreated; and 3) Dose Expansion Cohort 3: one to three prior treatments, one of
which could have been bevacizumab. A triplet Regimen (Regimen E: mirvetuximab soravtansine +
bevacizumab + carboplatin) will be opened to evaluate the safety and tolerability and to
assess any early signs of activity in participants dosed with the combination regimen. All
mirvetuximab soravtansine doses were calculated according to adjusted ideal body weight.

Inclusion Criteria:

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

- Folate receptor α (FRα) positive tumor expression as defined in the protocol

- Willing to provide an archival tumor tissue block or slides or undergo tumor biopsy.
New tumor biopsy (Cycle 2 Day 8) is required for Regimen D.

- Measurable disease

Exclusion Criteria:

- Primary platinum-refractory disease

- Diagnosis of clear cell, low grade ovarian cancer or mixed tumors

- Serious concurrent illness or clinically relevant active infection, including but not
limited to known diagnosis of human immunodeficiency virus (HIV) and hepatitis B or C,
as defined in the protocol

- Active autoimmune disease requiring systemic therapy in past 2 years (for Regimen D
only)

- Women who are pregnant or breastfeeding

- Male participants