Sacituzumab Govitecan in Patients With Metastatic Castration-Resistant Prostate Cancer Progressing on Second Generation AR-Directed Therapy

Inclusion Criteria: * Documented histological or cytological evidence of adenocarcinoma of the prostate * Documented metastatic disease on bone scan and/or CT scans * Currently receiving enzalutamide, darolutamide, apalutamide and/or abiraterone. Subjects who have received combination enzalutamide/abiraterone or combination apalutamide/abiraterone as part of clinical trials are allowed but will need to be receiving only a single agent ARSI at the time of study enrollment. Subjects who have received any other therapeutic investigational product directed towards the AR or androgen biosynthesis are allowed. Prior treatment with first-generation AR antagonists (i.e., bicalutamide, nilutamide, flutamide) before second generation AR-directed therapy is allowed. * Demonstrated disease progression while on enzalutamide, darolutamide, apalutamide, and/or abiraterone. Progressive disease is defined by one or more of the following: * A rise in prostate specific antigen (PSA) on two successive determinations at least one week apart and PSA level ≥2 ng/mL * Soft-tissue progression defined by RECIST 1.1 * Bone disease progression defined by Prostate Cancer Working Group 2 (PCWG2) with ≥2 new lesions on bone scan * A minimum serum PSA level of ≥2 ng/mL that is rising based on the PCWG2 criteria * ≥18 y ears of age * Castrate levels of testosterone (\<50 ng/dL \[1.74 nmol/L\]) * Undergone orchiectomy, or have been on Luteinizing hormone-releasing hormone (LHRH) agonists or antagonist…