Onconic Therapeutics reported a sharp turnaround in its first-quarter earnings, driven by strong sales of its gastroesophageal reflux drug Jaqbo (zastaprazan), one of Korea’s newest domestically developed treatments.

The company, a subsidiary of Jeil Pharmaceutical, posted 91.7 billion won ($6.54 million) in revenue for the quarter, a nearly sixfold increase from the same period last year. It recorded an operating profit of 15.8 billion won and a net profit of 18.8 billion won, reversing losses of about 3 billion won in both categories a year earlier.

Onconic attributed the gains to Jaqbo, a potassium-competitive acid blocker (P-CAB) approved in April 2024 and launched later that year. The drug generated 3.3 billion won in prescriptions in the fourth quarter of 2024 and 6.7 billion won in the first quarter of 2025, according to the market research firm UBIST, pushing its cumulative prescriptions to 10 billion won within six months.

Jaqbo is the third drug of its kind approved in Korea, following HK inno.N’s K-CAB (tegoprazan) and Daewoong Pharmaceutical’s Fexuclue (fexuprazan). Last month, Onconic raised its full-year revenue forecast by 54 percent to 24.9 billion won. With nearly 92 billion won in revenue already posted in the first quarter, the company said in Monday’s release that it is widely expected to exceed that figure.

Unlike many Korean biotech firms that rely on overseas licensing deals, Onconic said it brought Jaqbo to market on its own before going public. The company has signed licensing agreements in 26 countries, including China, India, Mexico and several in northern Europe. A phase 3 trial is underway in China, a market estimated to be worth 4 trillion won for acid-related drugs.

Company officials said they expect Jaqbo’s cash flow to support the development of additional drugs, including candidates in oncology.