Korean firms circumvent 1 patent on neuropathic pain drug Taleaje

Huons, Dong-A ST, and JW Pharmaceutical succeed in circumventing Taleaje’s composition patent

If formulation patents are also bypassed, generic launch may be advanced to after 2031

Generic drug makers have succeeded in circumventing the salt and composition patent protecting the neuropathic pain treatment Taleaje Tab (mirogabalin). If they also succeed in bypassing the formulation patent they are separately challenging, they may be able to move the generic launch timing forward to June 2031.

According to the pharmaceutical industry on the 28th, the Korean Intellectual Property Trial and Appeal Board ruled in favor of Huons, Dong-A ST, and JW Pharmaceutical in their passive scope confirmation trial against Daiichi Sankyo regarding Taleaje’s salt and composition patent (10-2142257).

Taleaje is protected by 3 patents: a substance patent (10-1335784) expiring in June 2031, a salt and composition patent expiring in April 2034, and a formulation patent (10-2425821) expiring in 2036.

Generic companies filed passive scope confirmation trials against the salt/composition patent in May last year. In addition to the 3 companies that won the first ruling, Kyongbo Pharmaceutical, Samjin Pharmaceutical, BC World Pharm, Dongwha Pharm, Daewoong Pharmaceutical, and HK inno.N also filed similar challenges. These companies additionally challenged the formulation patent as well.

Among the challengers, BC World Pharm, Dongwha Pharm, and HK inno.N voluntarily withdrew their trials and exited the patent challenge race. The remaining 6 companies continue their challenges. Following the recent favorable ruling, the industry expects KyungDong Pharmaceutical, Samjin Pharmaceutical, and Daewoong Pharmaceutical to succeed in bypassing the salt/composition patent.

If they additionally succeed in circumventing the formulation patent following their success with the salt and composition patents, the generic launch timing could be advanced to June 2031 when the substance patent expires.

Taleaje is used for neuropathic pain treatment. Daiichi Sankyo received approval for four dosage strengths (2.5mg, 5mg, 10mg, and 15mg) in January 2020.

However, the product failed to secure coverage under the National Health Insurance. It is currently being sold as a non-reimbursed medication. As of 2024, its sales revenue stood at approximately KRW 3.7 billion. Given that the product generates significant sales even without insurance coverage, analysts believe it is well worth the challenge for generic drug manufacturers.

If companies challenging the patent successfully obtain generic approval and secure insurance coverage, they are expected to compete in the neuropathic pain treatment market against pregabalin (brand name Lyrica) and gabapentin (brand name Neurontin).

Pregabalin and gabapentin are already covered by national health insurance and are reported to form a market worth KRW 200 billion annually. Additionally, potential competition exists with COX-2 inhibitor analgesics such as celecoxib (brand name Celebrex) and SNRI antidepressants such as duloxetine (brand name Cymbalta).