Enzalutamide, a Blockbuster Drug for Prostate Cancer, Approved in China with Seven Domestic Companies in the Pipeline

On November 20, enzalutamide, co-developed by Astellas and Pfizer, was approved for marketing in China for the treatment of metastatic hormone-sensitive prostate cancer. As one of the major drugs for prostate cancer, the approval of enzalutamide in China came more than seven years after its approval in the United States.

Enzalutamide is an androgen receptor inhibitor co-developed by Astellas and Medivation. The drug was initially approved by the FDA in August 2012 for the treatment of advanced castration-resistant prostate cancer under the brand name Xtandi. In August 2016, Pfizer acquired Medivation for $14 billion, thereby bringing this drug into its portfolio.

Enzalutamide Structural Formula

Enzalutamide is the first FDA-approved oral drug for both metastatic and non-metastatic castration-resistant prostate cancer. On April 16, 2018, Astellas/Pfizer submitted a marketing application for enzalutamide soft capsules in China, and on June 13, 2018, this application was included in the priority review by the CDE.

Prostate cancer is the second most common type of tumor in men worldwide, with approximately 1 in 9 men being diagnosed with prostate cancer during their lifetime. In 2018, there were about 1.3 million new cases globally. In the United States, it was estimated that 174,650 patients would be diagnosed with prostate cancer in 2019. In China, prostate cancer is the most common genitourinary cancer among men, with an incidence rate of approximately 9.8 per 100,000 people.

According to the PharmCube database, the compound patent for enzalutamide is expected to expire in 2026. In November 2018, Star-Tai Pharmaceutical, a subsidiary of Fosun Pharma, successfully challenged the invention patent for “diarylhydantoin compounds” of enzalutamide (Patent No. ZL200680025545.1), thereby removing this patent barrier for other domestic companies intending to file for generic enzalutamide approval.

Source: PharmCube NextPharma

As of now, the PharmaGo database by Medicine Magic shows that seven manufacturers in China have filed for approval of enzalutamide, including Chia Tai Tianqing, Hansoh Pharmaceutical, and Kelun Pharmaceutical. In 2018, global sales of Xtandi reached $3.624 billion.

Manufacturers of Enzalutamide for Domestic Registration in China

Abiraterone, also one of the current best-selling oral drugs for prostate cancer globally, has seen three generic versions approved in China this year from Hengrui Medicine, Chia Tai Tianqing, and Jiangxi Shanxiang Pharmaceutical. On September 6, Janssen’s next-generation prostate cancer drug, apalutamide tablets, received approval from the National Medical Products Administration (NMPA) for marketing, becoming the first next-generation androgen receptor inhibitor approved in China for patients with non-metastatic castration-resistant prostate cancer (nmCRPC). The approval of Astellas/Pfizer’s enzalutamide soft capsules will provide new treatment options for prostate cancer patients.