Study of Zelenectide Pevedotin in Participants With Advanced Breast Cancer

Exclusion Criteria

• •Prior treatment with any antibody drug conjugate (ADC) containing an Monomethyl Auristatin E (MMAE) (vedotin) payload or other MMAE-based therapy.
• •Known hypersensitivity or allergy to any of the ingredients of any of the study interventions, or to MMAE.
• •Previously tested HER2-positive (IHC 3+ or ISH+) on prior pathology testing (per ASCO-CAP guidelines).
• •Active keratitis or corneal ulcerations.
• •Active or untreated central nervous system (CNS) metastases.
• •Uncontrolled diabetes or hypertension.
• •Uncontrolled pleural effusion, pericardial effusion, or ascites requiring recurrent drainage procedures (once monthly or more frequently).
• •Active interstitial lung disease or pneumonitis requiring ongoing treatment with steroids (\>10mg/day of prednisone or equivalent) or other immunosuppressive medications.
• •Requirement, while on study, for treatment with strong inhibitors or strong inducers of human cytochrome P450 3A (CYP3A) or inhibitors of P-glycoprotein (P-gp) including herbal- or food-based inhibitors.
• •Prior treatment with any systemic anticancer therapy within 28 days or 5 half-lives, whichever is shorter, prior to first dose of study treatment