Korea’s Onconic Therapeutics, a subsidiary of Jeil Pharmaceutical, has locked in a $5 million milestone payment from China’s Livzon Pharmaceutical after the partner wrapped up a phase 3 trial of gastroesophageal reflux disease (GERD) pill zastaprazan and filed for marketing approval with regulators. 

The payout, tied to the drug known in Korea as Jaqbo, which debuted there in October 2024, marks the largest single milestone Onconic has collected to date.

The Kosdaq-listed biotech had already banked $15 million upfront when it licensed China rights to Livzon in March 2023. 

Since then, it has added $3 million for phase 3 initiation and $1.5 million for a manufacturing technology transfer. Another payment is expected if Chinese regulators clear the drug.

China is the world’s largest GERD market, valued at 4 trillion to 6 trillion won ($2.9 billion to $4.3 billion) annually, according to IQVIA. Its P-CAB drug class grew 81 percent last year to 241.4 billion won ($174 million). 

“This milestone marks a pivotal moment in our global expansion,” an Onconic spokesperson said in its release, noting plans to speed commercialization in India, Mexico and Latin America. 

The company has signed licensing and distribution deals for zastaprazan in 26 countries.