Rinatabart Sesutecan (Rina-S) for Advanced Solid Tumors (GCT1184-01/ PRO1184-001)

Inclusion Criteria:

Part A and B:

• Histologically or cytologically confirmed metastatic or unresectable solidmalignancy including ovarian cancer (must have epithelial ovarian cancer, primaryperitoneal cancer, or fallopian tube cancer), endometrial cancer, non-small celllung cancer (Part A), EGFR-mutated NSCLC (Part B), breast cancer (hormone receptorpositive, HER2-negative and triple-negative) (Part A), mesothelioma.

• Previously received therapies known to confer clinical benefit.

• Measurable disease per RECIST v1.1 for all tumor types other than pleuralmesothelioma which will use mRECIST v1.1 at baseline.

Part C:

Participants must have histologically or cytologically confirmed metastatic or unresectable epithelial ovarian cancer as specified below.

• High grade serous ovarian cancer, primary peritoneal cancer, or fallopian tubecancer (excluding endometrioid, clear cell carcinomas, mucinous, low grade, andthose with a sarcomatous or neuroendocrine element)

• Participants must have received 1 to 3 prior lines of therapy. Participants who had 1 to 4 prior lines of therapy are allowed if mirvetuximab soravtansine (MIRV) wasthe last line of therapy.

• Participants must have platinum-resistant ovarian cancer.

• Participants must have received prior bevacizumab.

• Participants with known or suspected deleterious germline or somatic BRCA mutations (as determined by Food and Drug Administration [FDA]-approved test in a ClinicalLaboratory Improvement Amendments [CLIA]-certified laboratory) and who achieved acomplete or partial response to platinum-based chemotherapy must have been treatedwith a poly ADP-ribose polymerase (PARP) inhibitor as maintenance treatment.

• Participants must have known FRα status based on an FDA approved test. Those who areFRα positive must have previously received MIRV, unless the participant has adocumented medical exception.

• Prior induction plus maintenance is considered 1 line of therapy, even if parts ofthe treatment regimen (induction or maintenance) are interrupted and/or resumed at alater date, in the absence of disease progression while on active treatment.

• A switch/change in regimen due solely to toxicity or participant preference (and notdisease progression) is not considered a separate line of therapy.

Part D:

Cohort D1 (Rina-S+carboplatin):

• Participants must have platinum-sensitive ovarian cancer.

• Participants must have received 1 to 3 prior lines of therapy.

Cohort D2 (Rina-S+bevacizumab):

• Participants must have platinum-refractory, platinum-resistant, orplatinum-sensitive ovarian cancer.

• Participants must have received 1 to 3 prior lines of therapy for platinum-resistantovarian cancer (PROC), and up to 4 prior lines of therapy for platinum-sensitiveovarian cancer (PSOC). Prior treatments may have included bevacizumab, PARPinhibitor, and MIRV.

Cohort D3 (Rina-S+pembrolizumab):

• Endometrial cancer (any subtype excluding sarcoma).

• Participants must have received prior platinum-based chemotherapy for recurrent oradvanced disease.

Exclusion Criteria:

• History of (non-infectious) interstitial lung disease (ILD)/pneumonitis thatrequired steroids within the past 2 years, has current ILD/pneumonitis, or wheresuspected ILD/pneumonitis cannot be ruled out by imaging at screening.

• Use of a strong cytochrome P450 3A (CYP3A) inhibitor within 14 days (dose escalationonly).

• Prior therapy with a topoisomerase 1 inhibitor-based antibody drug conjugate.

Note: Other protocol-defined inclusion/exclusion may apply.