Phase II CYPIDES Trial Insights: ODM-208/MK-5684 at ASCO-GU 2024

Orion Corporation has unveiled additional findings from the Phase II CYPIDES trial at the 2024 ASCO GU Cancers Symposium. The study focuses on the safety and efficacy of ODM-208, also known as MK-5684, an oral CYP11A1 inhibitor. This drug is being tested on patients with metastatic castration-resistant prostate cancer (mCRPC), both with and without androgen receptor ligand-binding domain (AR-LBD) mutations.

The drug has shown to effectively block the production of all steroid hormones, which are known to regulate prostate cancer even in its castration-resistant form. The Phase II CYPIDES trial included 134 patients who had been previously treated for mCRPC. They were administered 5mg of ODM-208 twice daily alongside hormone replacement therapy and ongoing androgen-deprivation therapy. The trial revealed that patients with AR-LBD mutations responded more favorably to the treatment, with a 50% or greater decrease in prostate-specific antigen (PSA) levels observed in 55.6% of these patients. In contrast, only 16.7% of AR-wild-type patients exhibited the same level of PSA reduction.

The adverse events associated with ODM-208 were clinically manageable, and the rate of serious adrenal insufficiency was low at 3.0% under hormone replacement therapy. The new data is in line with previously reported findings and reinforces the significance of hormone-based treatments for prostate cancer.

ODM-208 is an experimental oral medication developed by Orion for treating hormone-dependent cancers such as prostate cancer. It is being developed in collaboration with MSD and is currently undergoing two pivotal Phase 3 clinical trials, OMAHA1 and OMAHA2a, in combination with hormone replacement therapy. These trials are aimed at treating certain mCRPC patients, and enrollment is ongoing.

The results from the Phase II CYPIDES trial indicate that ODM-208 has the potential to be a significant new inhibitor of prostate cancer growth driven by the androgen receptor. The drug's impact on patients with AR-LBD mutations is particularly noteworthy, although it also shows benefits for AR-wild-type patients. Further data from the ongoing Phase 3 studies is eagerly anticipated to provide a more comprehensive understanding of the drug's efficacy and safety profile.