Generic Tagrisso and Xtandi approved in Korea

Patent avoidance key to early market entry

Xtandi’s compound patent set to expire in June this year

Chong Kun Dang and Menarini have each received approval for generic versions of the oncology drugs Tagrisso and Xtandi, respectively.

Particularly noteworthy is Chong Kun Dang's success in becoming the first in Korea to commercialize a generic version of Tagrisso, raising attention as to whether this will translate into early market entry.

On the 27th, the Ministry of Food and Drug Safety approved two dosage strengths of Chong Kun Dang’s ‘Otinib Tab’ as well as Menarini Korea’s ‘Enzalex Soft Cap 40 mg.’

CKD’s Otinib is the first approved generic version of osimertinib in Korea. The original product containing osimertinib is AstraZeneca’s Tagrisso.

Both Tagrisso and Otinib are indicated for patients with non-small cell lung cancer (NSCLC) harboring EGFR exon 19 deletions or exon 21 (L858R) substitution mutations.

Tagrisso recorded KRW 111 billion in domestic sales in 2023 (IQVIA data). Yuhan’s Leclaza (lazertinib) is its key competing product. Given its high commercial value, multiple later entrants are seeking early access to the market.

CKD has taken on the challenge to circumvent Tagrisso’s formulation patent, which is scheduled to expire in January 2035. Avoiding this patent would allow market entry in 2033, when Tagrisso’s compound patent expires. Kwangdong Pharmaceutical is also attempting the same patent challenge.

Although Otinib has now received regulatory approval, active market launch is not yet possible due to the remaining compound patent.

Nevertheless, analysts suggest that securing a priority marketing approval (generic exclusivity) to capture the generic market first could lead to high sales.

Menarini’s Enzalex Soft Cap contains enzalutamide as the active ingredient. The originator product is Astellas’ Xtandi and is used to treat prostate cancer. Xtandi recorded KRW 43.2 billion in domestic sales in 2023, according to IQVIA.

This is not the first approval of an Xtandi generic in Korea. Last year, Alvogen Korea and Daewon Pharm received approvals for Anadin Soft Cap and Enzadex Soft Cap, respectively. Earlier this month, HanAll Biopharma also succeeded in listing its enzalutamide generic, Enzaluta Soft Cap, on the MFDS approval registry.

With Xtandi’s compound patent set to expire in June, the opening of its generic market later this year is considered a strong possibility.

However, a key variable remains the formulation patent for enzalutamide, which is scheduled to expire in September 2033. Generic manufacturers have filed patent invalidation or circumvention actions targeting this formulation patent. Whether they succeed in avoiding the patent will determine if launches occur within the year.