New Investigational Treatments in Prostate Cancer

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Two new antiandrogen agents are currently being explored as treatments for patients with prostate cancer, explains Evan Y. Yu, MD. The first is the agent orteronel (TAK-700), which is a nonsteroidal, selective CYP17 lyase inhibitor. This agent is similar to abiraterone acetate, notes Yu, but seems to have less hydroxylase activity. As a result, orteronel can be administered without a corticosteroid at lower doses. However, the two phase III trials exploring this agent are utilizing a higher dose along with the coadministration of prednisone.

The second interesting agent is ARN-509, explains Yu. This treatment is a fully antagonistic inhibitor of the androgen receptor and is similar to enzalutamide. However, Yu suggests, this agent offers a unique therapeutic index compared to enzalutamide. In early studies, ARN-509 penetrated the central nervous system less than enzalutamide, resulting in fewer seizures.