Clinical phase I data on Orion’s ODM-208 were presented at the American Society of Clinical Oncology Genitourinary Cancers Symposium (ASCO GU).
“ODM-208 is a first-in-class CYP11A1-inhibitor and we are excited that this novel approach works in some of the patients who have only a few effective treatment options available. The first results of CYPIDES are encouraging, and more studies are needed to confirm the potential of ODM-208 as a treatment option for men with advanced prostate cancer. In addition, we are focusing on the safety findings of the study as well as are looking into the optimization of the adrenal balance of the patients through appropriate replacement therapy,” says Taru Blom (MD, PhD), Vice President, Global Development and CMO, Orion R&D.
CYPIDES phase 1 data shows that ODM-208 (a first-in-class oral, non-steroidal and selective inhibitor of CYP11A1, the first and rate-limiting enzyme of steroid biosynthesis) effectively blocked the production of all steroid hormones in men with metastatic castration-resistant prostate cancer (mCRPC) and showed promising anti-tumor activity in men progressing despite extensive prior treatment with both novel hormonal therapies (NHT’s) and taxanes. Treatment responses to ODM-208 especially occurred in men with activating androgen receptor (AR) mutations.
ODM-208 is a complete blocker of steroid biosynthesis that suppresses the production of all steroid hormones and their precursors that may activate the androgen receptor (AR) signalling pathway. This is particularly relevant in patients with AR ligand binding domain (LBD) activating somatic point mutations, a mechanism of resistance to hormone-based therapies in metastatic castration-resistant prostate cancer (mCRPC). During treatment the patients receive hormone replacement therapy to ensure sufficient adrenal function.
In CYPIDES phase I, a total of 44 patients with median age of 70 years received ODM-208. Overall, 32% of the patients achieved a PSA (prostate specific antigen) decrease of ≥50%. Of patients with AR LBD mutation (17), 68% achieved a PSA decrease of ≥50%. Also, prolonged treatment responses were observed especially in patients with AR LBD mutation. Although tolerated by most patients, the main safety finding was adrenal insufficiency (AI). Overall, 14 (32%) patients experienced severe adrenal insufficiency despite the replacement therapy requiring further adrenal supplementation after which the ODM-208 treatment commonly continued. Non-adrenal adverse events were unremarkable.