Expanded patent dispute over cancer drug 'Xtandi'

Major pharmaceutical companies have now joined

The number of companies challenging the composition patent for the prostate cancer treatment has expanded to six

Product photo of Xtandi

The number of companies challenging the patent for Astellas' prostate cancer treatment, 'Xtandi (enzalutamide)', has expanded to six.

 

Attention has been drawn to the fact that major pharmaceutical companies, such as Chong Kun Dang, Hanmi Pharmaceutical, and JW Pharmaceutical, have joined this latest patent challenge.

 

According to the pharmaceutical industry on August 19, Hanmi Pharmaceutical filed a petition for trial to confirm the scope of rights against Astellas for Xtandi's composition patent on August 18.

 

As a result, the total number of companies that have filed circumvention trials against Xtandi's composition patent has increased to six.

 

Earlier, Alvogen Korea was the first to file the trial on the 1st of this month, followed by Chong Kun Dang, JW Pharmaceutical, GL Pharma, and Kuhnil, where all filed the same trial.

 

The pharmaceutical industry is paying attention to the fact that major pharmaceutical companies, such as Chong Kun Dang, Hanmi Pharmaceutical, and JW Pharmaceutical, have successively joined this patent challenge.

 

This is because there have not been many cases where major pharmaceutical companies have simultaneously challenged patents for anti-cancer drugs.

 

Typically, there is a high preference for prescribing original anti-cancer drugs, especially in large hospitals.

 

Domestic pharmaceutical companies, which have strong sales capabilities for chronic disease treatments in clinics, have been hesitant to challenge patents for anti-cancer drugs for this reason.

 

Furthermore, even if they succeeded in a patent challenge and launched a generic, the profits generated were not significant, making major pharmaceutical companies even more reluctant.

 

There have been cases of patent challenges for liver cancer treatments like 'Lenvima (lenvatinib),' 'Cabometyx (cabozantinib),' and breast cancer treatment 'Ibrance (palbociclib).' However, these were sporadic challenges primarily led by Boryung, which has a separate oncology business unit, or Samyang Biopharm, which specializes in the generic oncology business.

 

In the case of the oncology drug patent, Hanmi Pharmaceutical was the only company challenging the 'Nexavar (sorafenib) patent.' Meanwhile, in the patent challenge for the prostate cancer treatment Xtandi, major pharmaceutical companies like Chong Kun Dang, Hanmi Pharmaceutical, and JW Pharmaceutical have successively filed trials.

 

If they win this trial, generic competition is expected to intensify after the substance patent expires in June 2026.

 

Xtandi is Astellas' prostate cancer treatment, protected by two patents: a substance patent that expires in June 2026 and a composition patent that expires in September 2033.

 

The plan for the generic companies is to circumvent the composition patent, which expires in 2033, and then launch their generics early around the expiration of the substance patent in 2026.

 

Astellas received approval for Xtandi Soft Cap in 2013.

 

Last year, it added two dosages of Xtandi tablets.

 

Xtandi competes with Janssen's 'Erleada (apalutamide)' and 'Zytiga (abiraterone)' in the first-line prostate cancer treatment market.

 

Recently, 'Akeega (abiraterone·niraparib),' a new first-line treatment, was launched.

 

Akeega is a drug that combines Zytiga with Takeda's Zejula (niraparib).

 

Recent trends indicate that while Zytiga's sales are declining following the launch of generics, Xtandi and Erleada are on an upward trend.

 

According to pharmaceutical market research firm IQVIA, Xtandi's sales increased by 1.9 times in four years, from KRW 23 billion in 2019 to KRW 43.2 billion in 2023.

 

It is estimated to have generated sales of around KRW 50 billion last year.