This clinical trial compares two medicines used to treat bleeding stomach ulcers in people in Indonesia. The researchers want to find out whether tegoprazan or lansoprazole is better at healing these ulcers after 2 weeks of treatment.

The main question this trial aims to answer is:

Which medicine, tegoprazan or lansoprazole, heals bleeding peptic ulcers better after 2 weeks of treatment? Researchers will compare tegoprazan to lansoprazole to see which one works better.

Participants in this trial will:

• Receive IV fluids and, if needed, a blood transfusion to stabilize their condition
• Receive a high dose of acid-reducing medicine for the first 72 hours
• Have an exam of the stomach using a thin scope (gastroscopy) within 24 hours of arriving at the hospital, with treatment to stop the bleeding if needed
• Take one of two combinations once a day, 30 minutes before breakfast, for 14 days: either lansoprazole (30 mg) plus a tegoprazan placebo, or tegoprazan (50 mg) plus a lansoprazole placebo. A placebo looks identical to the real drug but contains no active medicine. Neither participants nor researchers will know which one each person is taking.
• Be treated for H. pylori - a stomach bacteria that can cause ulcers - if they test positive for it
• Have a second gastroscopy after 14 days of treatment to check how well the ulcer has healed

Peptic ulcer disease, caused by damage to the stomach or duodenal lining from acid or pepsin, affects roughly 5-10% of the global population and has been rising in prevalence worldwide. Standard treatment relies on acid-suppressing drugs, particularly proton pump inhibitors (PPIs) like lansoprazole, which are effective but limited by a short half-life, dependence on food timing, and risks with long-term use such as rebound acid hypersecretion and gut dysbiosis. Potassium-competitive acid blockers (PCABs) such as tegoprazan represent a newer drug class that suppresses acid more rapidly, potently, and predictably than PPIs by directly and reversibly blocking the H+/K+ ATPase pump, without needing an acidic environment for activation. While tegoprazan and other PCABs have shown promising results in healing various types of ulcers and preventing rebleeding after endoscopic treatment, no prior studies have directly compared tegoprazan and lansoprazole specifically in bleeding peptic ulcers, nor evaluated tegoprazan's healing rate at the 2-week mark. This gap makes a head-to-head superiority trial between the two drugs in the Indonesian population both novel and clinically relevant.

All study subjects with symptoms of upper gastrointestinal bleeding and over the age of 18 will receive fluid resuscitation and blood transfusions, if necessary, as well as high-dose PPI therapy, followed by a gastroscopy within 24 hours of admission for initial assessment and a biopsy for H. pylori testing. If H. pylori infection is detected, triple therapy will be administered, consisting of amoxicillin 1000 mg twice a day, clarithromycin 500 mg twice a day, and a PPI or PCAB for 14 days.

All study subjects were randomly assigned using concealment methods prepared by the data processing team and divided into two groups based on the type of treatment to be administered. The first group received tegoprazan 50 mg in the morning, and the second group received lansoprazole 30 mg in the morning. Tegoprazan is in tablet form, and there is no data on its stability when made into capsules; therefore, this study used a double dummy for tegoprazan and lansoprazole.

The first group will receive one 50 mg tegoprazan tablet and one dummy capsule, while the second group will receive one 30 mg lansoprazole capsule and one dummy tablet. Both capsules and tablets are made identical in active and dummy form. Both medications will be taken together half an hour before breakfast to enhance effectiveness.

Each subject's allocation will be placed in a sealed envelope containing the treatment group number, with the subject's serial number written on the outside of the envelope. After 72 hours of high-dose PPI administration and the absence of hematemesis or melena, the data collection team will administer 17 sets of medications according to the treatment group number listed in the sealed envelope to the study subjects.

All study subjects will be monitored daily for complaints and rebleeding events. They will be reminded to take their medications daily and to schedule a repeat gastroscopy on day 15 via WhatsApp or SMS. Subjects will be contacted by the data collection team if there is no response, and the remaining medication will be calculated at the time of the repeat gastroscopy evaluation. Both groups received therapy for 14 days, followed by repeat gastroscopy on day 15, or the following day if day 15 fell on a holiday, to compare ulcer improvement at the same location as the initial gastroscopy.

Gastroscopy was performed by a Consultant Internal Medicine Gastroenterohepatologist (Sp.PD, K-GEH) or an endoscopist outside the research team. The gastroscopy performed a comprehensive evaluation of the mucosal condition of the mouth, esophagus, stomach, and duodenum. Photographs were taken of the proximal and distal esophagus (esophago-gastric junction), stomach (fundus, cardia, corpus, antrum, and pylorus), and duodenum (bulbus and descending part). All ulcers, their location, and the largest diameter of each ulcer were recorded using biopsy forceps. Mucosal biopsies were taken from the antrum (two), the corpus (one), and the ulcer margin. A biopsy was performed to determine the presence of H. pylori infection.

The gastroscopy results (pictured) were evaluated by the same specialist physician, K-GEH, appointed outside the research team to assess the degree of peptic ulcer disease (first gastroscopy) and ulcer healing (second gastroscopy).

Inclusion Criteria:

• Subjects aged 18 years and over.

• Subjects with upper gastrointestinal bleeding caused by peptic ulcers diagnosed by gastroscopy.

• Willing to participate in the entire clinical study process, including:

  1. . Fluid resuscitation and blood transfusion, if necessary,
  2. . High-dose PPI therapy for 72 hours,
  3. . Gastroscopy within 24 hours of hospital admission and endoscopic hemostatic therapy, if necessary,
  4. . Lansoprazole 30 mg or tegoprazan 50 mg therapy for 14 days,
  5. . Treatment for H. pylori infection if positive,
  6. . Repeat gastroscopy after 14 days of treatment to assess the progress of therapy.

Exclusion Criteria:

• Subjects with a history of allergy to tegoprazan or lansoprazole
• Subjects with a history of allergy to tegoprazan or lansoprazole.
• Subjects with ulcers caused by gastric or duodenal cancer.
• Subjects with comorbidities such as chronic kidney disease stage 3 or higher and decompensated liver cirrhosis.
• Patients who are heavy alcohol drinkers and have used chemotherapy drugs, bisphosphonates, or potassium supplements in the past 2 weeks.