Onconic Therapeutics announced in a regulatory filing on the 2nd that it has received approval from the Ministry of Food and Drug Safety for an amendment to its investigational new drug (IND) application for a Phase 3 clinical trial to add an indication for maintenance therapy following the treatment of erosive gastroesophageal reflux disease (GERD) with the domestically developed new drug Zastaprazan (JP-1366).

With this approval, the company will conduct a Phase 3 clinical trial to evaluate the efficacy and safety of Zastaprazan as a maintenance therapy in patients with erosive GERD whose healing has been confirmed via upper gastrointestinal endoscopy. The trial is designed as a multicenter, randomized, double-blind, active-controlled, parallel-group, non-inferiority study. It will be conducted at approximately 25 institutions, including Seoul National University Hospital, and will enroll around 384 participants. The investigational drug will be administered orally once daily before meals for a period of 24 weeks.

The primary endpoint is the proportion of patients who maintain healed erosive GERD status on upper gastrointestinal endoscopy at 24 weeks. The expected completion date is July 1, 2029.

The company explained that the objective of this trial is to demonstrate the non-inferiority of Zastaprazan as a maintenance therapy compared to the existing treatment, Lansoprazole. This amendment approval is the result of a clinical trial plan amendment application submitted on March 31. Zastaprazan 20mg is Korea's 37th domestically developed new drug, having received product approval from the Ministry of Food and Drug Safety and launched in April 2024.

The company plans to utilize the details of this clinical trial plan amendment approval in its press releases and investor relations materials. However, through its investment cautionary notes, the company advised that the statistical probability of a clinical trial drug receiving final approval as a pharmaceutical product is approximately 10%, and that results falling short of expectations during the clinical trial and product approval processes could lead to changes in or the discontinuation of commercialization plans.