Astellas Submits New Drug Application in China for Enzalutamide to Treat Metastatic Hormone-Sensitive Prostate Cancer

On September 19, Astellas (ALPMY.US) announced that the Center for Drug Evaluation (CDE) of the China National Medical Products Administration had accepted the new indication application for enzalutamide soft capsules (marketed as Xtandi) for marketing in China.Treatment of Metastatic Hormone-Sensitive Prostate Cancer (mHSPC). Public information shows that enzalutamide is aA specific androgen receptor (AR) inhibitor, which was previously approved in China for the treatment of castration-resistant prostate cancer.This application is also the third application for enzalutamide to be accepted in the field of advanced prostate cancer treatment in China.

It is understood that enzalutamide is an androgen receptor signaling inhibitor. It not only blocks the binding of androgens to the receptor, but also inhibits the transfer of the receptor into the cell nucleus, as well as the binding of the androgen receptor to DNA. ThereforeIt is not only an antagonist of the androgen receptor but also has an inhibitory effect on the androgen signaling pathway.

In China, enzalutamide has been previously approved for the treatment ofPatients with metastatic castration-resistant prostate cancer (mCRPC) and non-metastatic castration-resistant prostate cancer (nmCRPC).In December 2019, the US FDA also approved the expansion of enzalutamide’s indications to treat patients with metastatic hormone-sensitive prostate cancer. Astellas andPfizer(PFE.US) once noted in a press release that this approval makes Enzalutamide aTreatable for three different forms of advanced prostate cancer (non-metastatic and metastatic castration-resistant prostate cancer, and metastatic castration-sensitive prostate cancer)Oral therapy.

Moreover, according to the Astellas press release, the new indication application for enzalutamide in China is based on the results of the Phase 3 ARCHES study conducted in China. This is a multicenter, randomized, double-blind, placebo-controlled Phase 3 clinical trial conducted in male patients with metastatic hormone-sensitive prostate cancer (mHSPC). A total of 180 Chinese mHSPC patients were enrolled across 30 research centers in mainland China.The primary endpoint of the trial is the time to prostate-specific antigen (PSA) progression.PSA progression is defined as a ≥25% increase in PSA level from the lowest PSA value (i.e., the lowest PSA level observed at or after baseline) with an absolute increase of ≥2 µg/L (2 ng/mL), confirmed by a second consecutive measurement at least 3 weeks later.

Trial data show,The study met its primary endpoint, demonstrating a statistically significant improvement in time to prostate-specific antigen (PSA) progression (TTPP).In the primary analysis, the safety of enzalutamide in combination with ADT was generally consistent with the known safety profile of the drug. Additionally, the study met key secondary endpoints, showing that enzalutamide in combination with ADT significantly reduced the risk of radiographic progression-free survival (rPFS) and increased the proportion of patients reaching undetectable PSA levels compared to placebo plus ADT.

Editorial Responsibility: Guo Mingyu