Study of Apalutamide With Carotuximab in Metastatic, Castration-Resistant Prostate Cancer

Inclusion Criteria:

History of castration-resistant prostate cancer with rising PSA (prostate-specific antigen) on a contemporary ARSI (Androgen receptor (AR) signaling inhibitor: abiraterone, enzalutamide, darolutamide). Bicalutamide, nilutamide, and flutamide will not be considered as contemporary ARSIs
Patient must have had 1 and can have up to 2 prior AR targeted therapy with the exception of apalutamide.
Patients must decline or be ineligible for taxane therapy in the opinion of the treating physician.
All patients must agree to use an adequate method of contraception, in the opinion of the treating investigator, while on protocol treatment and for 3 months after the last dose of protocol treatment (apalutamide and/or carotuximab)

Exclusion Criteria:

Non-PSA producing prostate cancers such as small cell prostate cancers or those prostate cancers which exhibit radiographic progression without PSA rise
Prior use of apalutamide
Other prior malignancy requiring active anticancer therapy
Prior exposure to carotuximab or any CD105 targeted antibody
Active bleeding or pathologic medical conditions that carries a high bleeding risk
A known diagnosis of Osler-Weber-Rendu syndrome