Table 2 Newer agents under development for the treatment of mCRPC

Orteronel (TAK-700)

Non-steroidal, selective inhibitor of 17, 20lyase, an enzyme required for androgen biosynthesis.

The results of Phase III trial (ELM-PC 4) did not show any survival benefit in chemotherapy naïve patients. An improvement in rPFS was seen.

Fatigue, GI toxicity

RTOG and SWOG- TAK + LHRH agonist to test whether improvement in OS or not

Galeterone (TOK-001)

Next generation AR antagonist and CYP17A1 inhibitor

ARMOR 1- phase I study showed the drug is well tolerated [42]

Fatigue, Nausea, Diarrhea

ARMOR 2 is underway in 4 distinct populations

1. Metastatic and treatment naïve

2. Non metastatic and treatment naïve

3. Patients who have progressed on abiraterone

4. Patients who have progressed on enzalutamide

ARN-509

Inhibits AR translocation and AR binding to DNA, does not exhibit agonist properties in the context of AR over-expression

Results from phase I studies showed that the drug is well tolerated and PSA decline at 12 weeks (>50% from the baseline) were observed in 46.7% of the patients. [38]

Fatigue, nausea, pain

Phase II study is underway in patients with mCRPC (NCT01171898)