Phase 1/2 Study of Rina-S in Patients with Locally Advanced and/or Metastatic Solid Tumors

This study will test the safety, including side effects, and determine the
characteristics of a drug called Rina-S in participants with solid tumors.

Participants will have solid tumor cancer that has spread through the body (metastatic)
or cannot be removed with surgery (unresectable).

Inclusion Criteria:

Part A and B:

- Histologically or cytologically confirmed metastatic or unresectable solid
malignancy including ovarian cancer (must have epithelial ovarian cancer, primary
peritoneal cancer, or fallopian tube cancer), endometrial cancer, non-small cell
lung cancer (Part A), EGFR-mutated NSCLC (Part B), breast cancer (hormone receptor
positive, 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 pleural
mesothelioma 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 tube
cancer (excluding endometrioid, clear cell carcinomas, mucinous, low grade, and
those 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) was
the last line of therapy. Participants must have progressed radiographically on or
after their most recent 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 Clinical
Laboratory Improvement Amendments [CLIA]-certified laboratory) and who achieved a
complete or partial response to platinum-based chemotherapy must have been treated
with a poly ADP-ribose polymerase (PARP) inhibitor as maintenance treatment.

- Participants must have known FRα status based on an FDA approved test. Those who are
FRα positive must have previously received MIRV, unless the participant has a
documented medical exception.

- Participants who are FRα negative, in accordance with the FDA approved test (Ventana
folate receptor [FOLR1] RxDx Assay), and were treated with MIRV, are excluded.

- Measurable disease per the RECIST v1.1 at baseline.

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 primary platinum-refractory, platinum-resistant, or
platinum-sensitive ovarian cancer.

- Participants with primary platinum-refractory ovarian cancer must have received ≤2
prior lines of therapy. Primary platinum-refractory ovarian cancer is defined as a
lack of response or by progression within 91 days after completing front-line
platinum containing therapy.

- Participants must have received 1 to 3 prior lines of therapy for platinum-resistant
ovarian cancer (PROC), and up to 4 prior lines of therapy for platinum-sensitive
ovarian cancer (PSOC). Prior treatments may have included bevacizumab, PARP
inhibitor, and MIRV.

- Participants with PSOC must have disease progression on or after maintenance
treatment, or at least 6 months (>183 days) or more from the last dose of
platinum-based therapy.

Cohort D3 (Rina-S+pembrolizumab):

- Endometrial cancer (any subtype excluding sarcoma).

- Participants must have received prior platinum-based chemotherapy for recurrent or
advanced disease.

Part F:

- Participants must have histologically or cytologically confirmed endometrial cancer
as specified below.

- Advanced, recurrent, metastatic, or primary unresectable endometrial cancer (any
subtype excluding neuroendocrine tumors, carcinosarcoma, or endometrial sarcoma)

- Participants must have received 1 to 3 prior lines of therapy in advanced,
recurrent, or metastatic setting, and must have progressed radiographically on or
after their most recent line of therapy:

- Participants must have received prior platinum-based chemotherapy and a programmed
death-ligand 1 (PD-[L])1 inhibitor.

- Participants who progress >12 months after completion of prior adjuvant or
neoadjuvant platinum-based chemotherapy must receive 1 additional cytotoxic systemic
treatment prior to enrollment in this study.

- Hormonal therapy alone (i.e., without chemotherapy) will not be counted as a
separate line of therapy.

- Measurable disease per the RECIST Version 1.1 at baseline.

Exclusion Criteria:

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

- Use of a strong cytochrome P450 3A (CYP3A) inhibitor within 14 days (dose escalation
only).

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

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