Orion and Bayer have submitted an application to the Japanese Ministry of Health, Labor and Welfare (MHLW) seeking marketing authorisation for darolutamide to be applied in the treatment castration-resistant prostate cancer (CRPC).

Being co-developed by the companies, the drug is a non-steroidal androgen receptor (AR) antagonist with high affinity for the receptor.

The drug is designed to inhibit the receptor function and the prostate cancer cells growth.

Data from preclinical studies showed lower blood-brain barrier penetration with darolutamide when compared to existing AR antagonists.

The application submitted to MHLW is supported by results from the Phase III Aramis clinical trial conducted to assess the safety and efficacy of oral darolutamide in 1,509 non-metastatic CRPC (nmCRPC) patients.

ARAMIS enrolled patients who were receiving androgen deprivation therapy (ADT) and at high risk of developing metastatic disease.

“Twice a day 600mg darolutamide plus ADT led to statistically significant improvement in metastasis-free survival during the trial.”

Twice a day 600mg darolutamide plus ADT led to statistically significant improvement in metastasis-free survival (MFS) during the trial.

Orion Research and Development senior vice-president Christer Nordstedt said: “Darolutamide is highly effective in the patient population with non-metastatic castration-resistant prostate cancer, and it has a side-effect profile that parallels that of placebo.

“Patients who received darolutamide had substantially longer MFS in the ARAMIS trial, and there was also a strong trend for improved overall survival. These results are truly exciting. We are looking forward to taking the next steps in bringing darolutamide to men with nmCRPC and their treating physicians.”

Apart from the ARAMIS trial in nmCRPC patients, the drug is being further studied in a separate Phase III trial called ARASENS involving metastatic hormone-sensitive prostate cancer patients.

Last month, Orion and Bayer submitted a new drug application (NDA) to the US Food and Drug Administration (FDA) to obtain approval for the drug in men with nmCRPC.