Chong Kun Dang Files Patent of Low-dose Overactive Bladder Drug

Chong Kun Dang, which released overactive bladder treatment Selebeta SR Tab. 25mg (mirabegron) last year, recently registered a drug patent to the Ministry of Food and Drug Safety.

As Chong Kun Dang is the only local drugmaker selling a low-dose generic drug of Betmiga, the initial therapy by Astellas Pharma, Chong Kun Dang, may be trying to use the patent to thwart the market entry of latecomer generic drugs, observers said.

According to the government’s drug information site, Chong Kun Dang’s Selebeta SR Tab. 25mg was registered in the list of patented medicines on Thursday.

On March 17, 2017, Chong Kun Dang applied for the patent of “Pharmaceutical composition for release control, comprising mirabegron or salt thereof.”

On November 26, 2019, the Korean Intellectual Property Office (KIPO) granted the patent registration (registration number: 10-2051132-0000).

Following the KIPO’s decision, Chong Kun Dang’s patent of Selebeta SR Tab. will be valid until March 17, 2037.

Selebeta is a generic drug of Astellas’ original drug, Betmiga.

Chong Kun Dang released the generic copy after winning a patent lawsuit against Astellas in Korea.

In 2015, Chong Kun Dang filed a trial to the Intellectual Property Trial and Appeal Board, claiming that its generic drug did not infringe Astellas’ patent of Betmiga.

The IPTAB ruled in favor of Chong Kun Dang in the first trial in December 2019 and the second in January 2021.

After successfully avoiding the Betmiga patent, Chong Kun Dang released Selebeta SR Tab. 50mg in July 2020. Then, it obtained the regulatory nod for Selebeta SR Tab. 25mg on Oct. 25 last year and rolled out the product.

Excluding Betmiga SR 25mg, Chong Kun Dang’s Selebeta SR 25mg is Korea's only low-dose overactive bladder treatment.

Hanmi Pharmaceutical, which also won the patent suit against Astellas, released Mirabek SR Tab. 50mg but not a low-dose tablet.

After Chong Kun Dang and Hanmi nullified the patent of Betmiga, the two companies’ exclusive rights to sell their generic drugs expired in February 2021. This will likely allow more generic drugmakers to enter the overactive bladder treatment market.

Twenty-six Korean pharmaceutical companies, including Daewoong Pharmaceutical, Boryung Pharmaceutical, and Daewon Pharmaceutical, obtained the marketing approval for high-dose Betmiga generic copies.

Outpatient prescriptions of mirabegron-using overactive bladder treatments reached approximately 77 billion won ($64.5 million) in 2021, according to UBIST data.

Source: koreabiomed.com

Editor: IPRdaily-Rene