Mass General - Division of Clinical Research

Part A: - Pathologically confirmed diagnosis of one of the following tumor types: - Ovarian cancer (epithelial ovarian cancer, primary peritoneal cancer, or fallopian tube cancer) - Endometrial cancer (any subtype excluding sarcoma) - Triple negative breast cancer (TNBC) - Non-small cell lung cancer (NSCLC) - Metastatic or unresectable locally advanced, recurrent, disease not amenable to further local therapy following prior systemic therapies known to confer clinical benefit. Part B: - Participants must have a histologically or cytologically confirmed metastatic or unresectable solid malignancy as specified below: - Ovarian cancer - TNBC - Endometrial cancer - NSCLC - Measurable disease at baseline as defined per RECIST, Version 1.1

• Prior treatment with anti-PTK7-directed therapy. - Had progressive disease as best response while on treatment with an auristatin (eg, a vedotin or pelidotin)- based ADC as the most recent line of therapy. - History of another malignancy within 3 years before the first dose of study drug, or any evidence of residual disease from a previously diagnosed malignancy. Exceptions are malignancies with a negligible risk of metastasis or death (eg, 5-year overall survival [OS] ≥90%) - Known active central nervous system metastases, including carcinomatous meningitis. Participants with brain metastases may participate provided the metastases have been treated and are stable for at least 4 weeks prior to the first dose of study drug, they have no new or enlarging brain metastases and have discontinued corticosteroids prescribed for symptoms associated with brain metastases for at least 7 days prior to the first dose of study drug. Participants with a history of brain metastases, suspected new brain metastases, or a diagnosis of NSCLC or breast cancer should have a computed tomography (CT)/ magnetic resonance imaging (MRI) scan of the brain at screening. - Participants with active or chronic corneal disorders, history of corneal transplantation, or any clinically significant corneal disease that prevents adequate monitoring of potential drug-induced keratopathy. Note: Participants with other active ocular conditions requiring ongoing therapy and/or monitoring must be discussed with the sponsor prior to enrollment. Additional protocol defined inclusion/exclusion criteria may apply.