Study of Upifitamab Rilsodotin in Combination With Carboplatin in Participants With High-grade Serous Ovarian Cancer

Inclusion Criteria:

Participant must be at least 18 years of age, and female; Participant must be able to understand the study procedures and agree to participate in the study by providing informed consent

* Participants must have a histological diagnosis of metastatic or recurrent high-grade serous ovarian cancer, which includes fallopian tube, or primary peritoneal cancer.
* Participant has received 1 to 3 prior lines of therapy for their ovarian cancer; a non-platinum-based chemotherapy regimen is permitted provided it is not the most recent line of therapy. Participant must have platinum-sensitive recurrent disease
* Participant must have an ECOG performance status 0 or 1
* Participant must have measurable disease as per RECIST v1.1
* Tumor sample must be provided, either an archival tumor tissue block or slides or, if not available, a tumor tissue block or slides from a new tumor biopsy obtained through a low-risk, medically routine procedure.
* Participants with toxicity from prior therapy or surgical procedures must have recovered to ≤ Grade 1. Participants with alopecia, stable immune-related toxicity such as hypothyroidism on hormone replacement, or adrenal insufficiency treated with ≤10 mg daily prednisone (or equivalent), after prior taxane therapy are exceptions to this criterion and may qualify for this study.
* Participants must have cardiac left ventricular ejection fraction (LVEF) ≥50% or ≥ the institution's lower limit of normal as measured by either Echo or MUGA scan
* Participants must have adequate organ function within 14 days prior to enrollment
* A female participant is eligible to participate if she is not pregnant or breastfeeding, if she is not a woman of childbearing potential (WOCBP), or if she is a WOCBP potential and using a contraceptive method that is highly effective.

Exclusion Criteria:

* Participant has known sensitivity to any of the study medications, or components thereof, or a history of drug or allergy that contraindicates their participation
* Participant is unable or unlikely to comply with dosing schedule and study evaluations.
* Participant has a prior hypersensitivity reaction to carboplatin requiring desensitization or discontinuation.
* Participant has prior platelet or neutrophil toxicity to carboplatin-containing therapy requiring dose reduction to AUC \<5 mg x mL/min in the most recent regimen containing carboplatin
* Known history of CTCAE version 5.0 Grade 4 thrombocytopenia OR history of bleeding in association with any grade thrombocytopenia
* Participant has had major surgery within 28 days of starting study treatment, systemic anticancer therapy within the lesser of 28 days or 5 half-lives of the prior therapy before starting study treatment (14 days or 5 half-lives for small molecule targeted therapy), or recent radiation therapy with unresolved toxicity or within a time window of potential toxicity
* Participant has received prior treatment with mirvetuximab soravtansine or another ADC containing an auristatin or maytansinoid payload.
* Participant has untreated CNS metastases (including new and progressive brain metastases), history of leptomeningeal metastasis, or carcinomatous meningitis.
* Has a diagnosis of additional malignancy that required treatment within 2 years prior to screening, except for adequately treated basal cell or squamous cell skin cancer, or carcinoma in situ of the breast or of the cervix
* Participant is unwilling to be transfused with blood components.
* Participant is receiving concurrent anti-cancer therapy (e.g. chemotherapy, radiation therapy, biologic therapy, immunotherapy, hormonal therapy, investigational therapy).