A Study to Assess Change in Disease Activity and Adverse Events in Adult Participants With Gynecologic Cancers Receiving Intravenous Infusion of IMGN151 as Monotherapy or in Combination With Other Therapies

A Phase 1b Dose Escalation and Expansion Study of IMGN151 as Monotherapy and in Combination With Other Anti-Cancer Therapies in Subjects With Gynecologic Cancers

Cancer is a condition where cells in a specific part of body grow and reproduce uncontrollably. The purpose of this study is to assess safety and tolerability of IMGN151 when given as monotherapy and in combination with other anti-cancer therapies in adult participants with gynecologic cancers.

IMGN151 is an investigational drug being developed for the treatment of gynecologic cancers. Participants are placed in 1 of 4 groups, called treatment arms. Each group receives a different treatment. Around 377 participants with gynecologic cancers will be enrolled in the study at approximately 50 sites worldwide.

Participants will receive intravenous infusions of IMGN151 as monotherapy or in combination with anti-cancer therapies according to their assigned study arm. In Arm A, participants will receive IMGN151 in combination with carboplatin on Day 1 of each cycle. In Arm B, participants will receive IMGN151 in combination with olaparib, twice a day (BID) on Day 1 of each cycle. In Arm C, participants will receive IMGN151 in combination with bevacizumab on Day 1 of each cycle. In Arm D, participants will receive IMGN151 as monotherapy on Day 1 of each cycle. In Arm E, participants will receive IMGN151 as monotherapy on Day 1 of each cycle. In Arm F, participants will receive IMGN151 as monotherapy on Day 1 of each cycle. The total study duration will be approximately 3 years.

There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at a hospital or clinic and may require frequent medical assessments, blood tests, and scans.

Inclusion Criteria:

• ECOG performance status of 0 or 1

• Participants (except for platinum-sensitive ovarian, fallopian tube, and primary peritoneal cancer (PSOC) participants without disease progression after platinum combination standard of care therapy in Arms B and D) will have ≥ 1 lesion that meets the definition of measurable disease by RECIST v1.1 (radiographically measured by the investigator).

• Participants will have high-grade serous epithelial ovarian, fallopian tube, and primary peritoneal cancers (EOC).

• Participant has completed prior therapy within the specified times below:

  • Systemic antineoplastic therapy within 5 half-lives or 4 weeks (whichever is shorter) prior to the first dose of IMGN151.
  • Focal radiation completed ≥ 2 weeks prior to the first dose of study treatment.

Exclusion Criteria:

• Participants with ovarian cancer with histologies including: endometrioid, clear cell, mucinous, or sarcomatous histology, mixed tumors containing any of the above histologies, as well a low-grade or borderline ovarian tumor.
• History of clinically significant medical conditions or any other reason that the investigator determines would interfere with the participant's participation in this study or would make the participant an unsuitable candidate to receive study treatment.
• Prior treatment with FRα-targeting therapy.
• Prior wide-field radiotherapy affecting more than 20% of the bone marrow.