Orteronel, discovered by Takeda, is an oral, non-steroidal androgen synthesis inhibitor that has been shown in pre-clinical studies to selectively inhibit the 17, 20 lyase enzymes which help produce steroidal androgens in the testes and adrenal glands.
The two trials are known as the ELM-PC (Evaluation of the Lyase inhibitor in Metastatic Prostate Cancer) trials.
Of the two, one trial (C21004) is a randomized, double-blind and multi-center trial of prednisolone plus orteronel or placebo in patients with chemotherapy-naive metastatic castration-resistant prostate cancer (mCRPC).
The second (C21005) is a randomized, double-blind and multi-center trial of prednisolone plus TAK-700 or placebo in patients with mCRPC that have progressed during or following docetaxel-based therapy.