Orion Corp. and Bayer Healthcare AG, part of Bayer AG, have begun to enroll patients in a phase III trial of ODM-201, an oral androgen receptor (AR) inhibitor the companies are co-developing to treat castration-resistant prostate cancer (CPRC). Supported by a €50 million (US$68 million) up-front Bayer paid Orion at the collaboration's June start, the study will test ODM-201 in men with non-metastatic CPRC who have rising prostate-specific antigen levels.