- Inhibition of angiogenesis has demonstrable antitumor efficacy against castrate-resistant prostate cancer (CRPC). TRC105 is a human/murine chimeric immunoglobulin heavy constant gamma 1 (IgG1) kappa monoclonal antibody that binds to human CD105 (endoglin), thus inhibiting angiogenesis and tumor growth. Data from an ongoing phase I clinical trial suggest that TRC105 is well tolerated with evidence of clinical efficacy in patients with metastatic CRPC.