• Number of Participants With Gastric Ulcer and/or Duodenal Ulcer [ Time Frame: 18 Months ] [ Designated as safety issue: No ]
  The number of participants that developed gastric ulcer and/or duodenal ulcer at month 18 or final visit. Ulcers are defined as mucosal defect with white coating 3 mm or greater.
  
  

• Change From Baseline in Gastric Mucosal Injury Assessed by Lanza Score (Partially Revised) (Month 3) [ Time Frame: Baseline and Month 3. ] [ Designated as safety issue: No ]
  The Lanza score (partially revised) attributes the severity of induced erosive mucosal injury in the stomach, graded on a 5 point scale (0=normal; 1= erosion/hemorrhage in one area of the stomach and <1 lesion; 2= erosion/hemorrhage in one area of the stomach with 2-5 lesions; 3= erosion/hemorrhage in two areas in the stomach/one area involves >6 lesions; 4= erosion/hemorrhage appear in three or more areas in the stomach). Erosions are mucosal defect < 3 mm. Ulcers are mucosal defect with white coating ≥ 3 mm. Higher scores indicate greater severity of gastric mucosal injury.
  
  
• Change From Baseline in Gastric Mucosal Injury Assessed by Lanza Score (Partially Revised) (Month 6) [ Time Frame: Baseline and Month 6. ] [ Designated as safety issue: No ]
  The Lanza score (partially revised) attributes the severity of induced erosive mucosal injury in the stomach, graded on a 5 point scale (0=normal; 1= erosion/hemorrhage in one area of the stomach and <1 lesion; 2= erosion/hemorrhage in one area of the stomach with 2-5 lesions; 3= erosion/hemorrhage in two areas in the stomach/one area involves >6 lesions; 4= erosion/hemorrhage appear in three or more areas in the stomach). Erosions are mucosal defect < 3 mm. Ulcers are mucosal defect with white coating ≥ 3 mm. Higher scores indicate greater severity of gastric mucosal injury.
  
  
• Change From Baseline in Gastric Mucosal Injury Assessed by Lanza Score (Partially Revised) (Month 9) [ Time Frame: Baseline and Month 9. ] [ Designated as safety issue: No ]
  The Lanza score (partially revised) attributes the severity of induced erosive mucosal injury in the stomach, graded on a 5 point scale (0=normal; 1= erosion/hemorrhage in one area of the stomach and <1 lesion; 2= erosion/hemorrhage in one area of the stomach with 2-5 lesions; 3= erosion/hemorrhage in two areas in the stomach/one area involves >6 lesions; 4= erosion/hemorrhage appear in three or more areas in the stomach). Erosions are mucosal defect < 3 mm. Ulcers are mucosal defect with white coating ≥ 3 mm. Higher scores indicate greater severity of gastric mucosal injury.
  
  
• Change From Baseline in Gastric Mucosal Injury Assessed by Lanza Score (Partially Revised) (Month 12) [ Time Frame: Baseline and Month 12. ] [ Designated as safety issue: No ]
  The Lanza score (partially revised) attributes the severity of induced erosive mucosal injury in the stomach, graded on a 5 point scale (0=normal; 1= erosion/hemorrhage in one area of the stomach and <1 lesion; 2= erosion/hemorrhage in one area of the stomach with 2-5 lesions; 3= erosion/hemorrhage in two areas in the stomach/one area involves >6 lesions; 4= erosion/hemorrhage appear in three or more areas in the stomach). Erosions are mucosal defect < 3 mm. Ulcers are mucosal defect with white coating ≥ 3 mm. Higher scores indicate greater severity of gastric mucosal injury.
  
  
• Change From Baseline in Gastric Mucosal Injury Assessed by Lanza Score (Partially Revised) (Month 18) [ Time Frame: Baseline and Month 18. ] [ Designated as safety issue: No ]
  The Lanza score (partially revised) attributes the severity of induced erosive mucosal injury in the stomach, graded on a 5 point scale (0=normal; 1= erosion/hemorrhage in one area of the stomach and <1 lesion; 2= erosion/hemorrhage in one area of the stomach with 2-5 lesions; 3= erosion/hemorrhage in two areas in the stomach/one area involves >6 lesions; 4= erosion/hemorrhage appear in three or more areas in the stomach). Erosions are mucosal defect < 3 mm. Ulcers are mucosal defect with white coating ≥ 3 mm. Higher scores indicate greater severity of gastric mucosal injury.
  
  
• Change From Baseline in Duodenal Mucosal Injury Assessed by Lanza Score (Partially Revised) (Month 3) [ Time Frame: Baseline and Month 3. ] [ Designated as safety issue: No ]
  The Lanza score (partially revised) attributes the severity of induced erosive mucosal injury in the duodenum, graded on a 4 point scale (0=normal; 1= erosion and hemorrhage are localized in one area of the duodenum and < 1 lesion; 2= 2 to 5 lesions ; 3= > 6 lesions). Erosions are defined as mucosal defect < 3 mm. Ulcers are defined as mucosal defect with white coating ≥ 3 mm. Higher scores indicate greater severity of duodenal mucosal injury.
  
  
• Change From Baseline in Duodenal Mucosal Injury Assessed by Lanza Score (Partially Revised) (Month 6) [ Time Frame: Baseline and Month 6. ] [ Designated as safety issue: No ]
  The Lanza score (partially revised) attributes the severity of induced erosive mucosal injury in the duodenum, graded on a 4 point scale (0=normal; 1= erosion and hemorrhage are localized in one area of the duodenum and < 1 lesion; 2= 2 to 5 lesions ; 3= > 6 lesions). Erosions are defined as mucosal defect < 3 mm. Ulcers are defined as mucosal defect with white coating ≥ 3 mm. Higher scores indicate greater severity of duodenal mucosal injury.
  
  
• Change From Baseline in Duodenal Mucosal Injury Assessed by Lanza Score (Partially Revised) (Month 9) [ Time Frame: Baseline and Month 9. ] [ Designated as safety issue: No ]
  The Lanza score (partially revised) attributes the severity of induced erosive mucosal injury in the duodenum, graded on a 4 point scale (0=normal; 1= erosion and hemorrhage are localized in one area of the duodenum and < 1 lesion; 2= 2 to 5 lesions ; 3= > 6 lesions). Erosions are defined as mucosal defect < 3 mm. Ulcers are defined as mucosal defect with white coating ≥ 3 mm. Higher scores indicate greater severity of duodenal mucosal injury.
  
  
• Change From Baseline in Duodenal Mucosal Injury Assessed by Lanza Score (Partially Revised) (Month 12) [ Time Frame: Baseline and Month 12. ] [ Designated as safety issue: No ]
  The Lanza score (partially revised) attributes the severity of induced erosive mucosal injury in the duodenum, graded on a 4 point scale (0=normal; 1= erosion and hemorrhage are localized in one area of the duodenum and < 1 lesion; 2= 2 to 5 lesions ; 3= > 6 lesions). Erosions are defined as mucosal defect < 3 mm. Ulcers are defined as mucosal defect with white coating ≥ 3 mm. Higher scores indicate greater severity of duodenal mucosal injury.
  
  
• Change From Baseline in Duodenal Mucosal Injury Assessed by Lanza Score (Partially Revised) (Month 18) [ Time Frame: Baseline and Month 18. ] [ Designated as safety issue: No ]
  The Lanza score (partially revised) attributes the severity of induced erosive mucosal injury in the duodenum, graded on a 4 point scale (0=normal; 1= erosion and hemorrhage are localized in one area of the duodenum and < 1 lesion; 2= 2 to 5 lesions ; 3= > 6 lesions). Erosions are defined as mucosal defect < 3 mm. Ulcers are defined as mucosal defect with white coating ≥ 3 mm. Higher scores indicate greater severity of duodenal mucosal injury.
  
  
• Number of Participants With Gastric or Duodenal Ulcer or Gastric or Duodenal Hemorrhagic Lesion (Upper Gastrointestinal Hemorrhage) [ Time Frame: 18 Months ] [ Designated as safety issue: No ]
  Number of participants with gastric or duodenal ulcer or gastric or duodenal hemorrhagic lesion (upper gastrointestinal hemorrhage) from baseline through month 18 or final visit. Ulcers are defined as mucosal defect with white coating 3 mm or greater.
  
  
• Change From Baseline in Severity of Postprandial Pain Gastrointestinal Symptom (Month 3) [ Time Frame: Baseline and Month 3. ] [ Designated as safety issue: No ]
  Postprandial pain is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Postprandial Pain Gastrointestinal Symptom (Month 6) [ Time Frame: Baseline and Month 6. ] [ Designated as safety issue: No ]
  Postprandial pain is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Postprandial Pain Gastrointestinal Symptom (Month 9) [ Time Frame: Baseline and Month 9. ] [ Designated as safety issue: No ]
  Postprandial pain is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Postprandial Pain Gastrointestinal Symptom (Month 12) [ Time Frame: Baseline and Month 12. ] [ Designated as safety issue: No ]
  Postprandial pain is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Postprandial Pain Gastrointestinal Symptom (Month 18) [ Time Frame: Baseline and Month 18. ] [ Designated as safety issue: No ]
  Postprandial pain is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Hunger and Nighttime Pain Gastrointestinal Symptom (Month 3) [ Time Frame: Baseline and Month 3. ] [ Designated as safety issue: No ]
  Hunger and nighttime pain is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Hunger and Nighttime Pain Gastrointestinal Symptom (Month 6) [ Time Frame: Baseline and Month 6. ] [ Designated as safety issue: No ]
  Hunger and nighttime pain is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Hunger and Nighttime Pain Gastrointestinal Symptom (Month 9) [ Time Frame: Baseline and Month 9. ] [ Designated as safety issue: No ]
  Hunger and nighttime pain is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Hunger and Nighttime Pain Gastrointestinal Symptom (Month 12) [ Time Frame: Baseline and Month 12. ] [ Designated as safety issue: No ]
  Hunger and nighttime pain is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Hunger and Nighttime Pain Gastrointestinal Symptom (Month 18) [ Time Frame: Baseline and Month 18. ] [ Designated as safety issue: No ]
  Hunger and nighttime pain is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Enlarged Abdomen Gastrointestinal Symptom (Month 3) [ Time Frame: Baseline and Month 3. ] [ Designated as safety issue: No ]
  Feeling of enlarged abdomen is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Enlarged Abdomen Gastrointestinal Symptom (Month 6) [ Time Frame: Baseline and Month 6. ] [ Designated as safety issue: No ]
  Feeling of enlarged abdomen is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Enlarged Abdomen Gastrointestinal Symptom (Month 9) [ Time Frame: Baseline and Month 9. ] [ Designated as safety issue: No ]
  Feeling of enlarged abdomen is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Enlarged Abdomen Gastrointestinal Symptom (Month 12) [ Time Frame: Baseline and Month 12. ] [ Designated as safety issue: No ]
  Feeling of enlarged abdomen is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Enlarged Abdomen Gastrointestinal Symptom (Month 18) [ Time Frame: Baseline and Month 18. ] [ Designated as safety issue: No ]
  Feeling of enlarged abdomen is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Nausea Gastrointestinal Symptom (Month 3) [ Time Frame: Baseline and Month 3. ] [ Designated as safety issue: No ]
  Feeling of nausea is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Nausea Gastrointestinal Symptom (Month 6) [ Time Frame: Baseline and Month 6. ] [ Designated as safety issue: No ]
  Feeling of nausea is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Nausea Gastrointestinal Symptom (Month 9) [ Time Frame: Baseline and Month 9. ] [ Designated as safety issue: No ]
  Feeling of nausea is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Nausea Gastrointestinal Symptom (Month 12) [ Time Frame: Baseline and Month 12. ] [ Designated as safety issue: No ]
  Feeling of nausea is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Nausea Gastrointestinal Symptom (Month 18) [ Time Frame: Baseline and Month 18. ] [ Designated as safety issue: No ]
  Feeling of nausea is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Heartburn Gastrointestinal Symptom (Month 3) [ Time Frame: Baseline and Month 3. ] [ Designated as safety issue: No ]
  Feeling of heartburn is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Heartburn Gastrointestinal Symptom (Month 6) [ Time Frame: Baseline and Month 6. ] [ Designated as safety issue: No ]
  Feeling of heartburn is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Heartburn Gastrointestinal Symptom (Month 9) [ Time Frame: Baseline and Month 9. ] [ Designated as safety issue: No ]
  Feeling of heartburn is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Heartburn Gastrointestinal Symptom (Month 12) [ Time Frame: Baseline and Month 12. ] [ Designated as safety issue: No ]
  Feeling of heartburn is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Feeling of Heartburn Gastrointestinal Symptom (Month 18) [ Time Frame: Baseline and Month 18. ] [ Designated as safety issue: No ]
  Feeling of heartburn is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Anorexia Gastrointestinal Symptom (Month 3) [ Time Frame: Baseline and Month 3. ] [ Designated as safety issue: No ]
  Severity of anorexia is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Anorexia Gastrointestinal Symptom (Month 6) [ Time Frame: Baseline and Month 6. ] [ Designated as safety issue: No ]
  Severity of anorexia is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Anorexia Gastrointestinal Symptom (Month 9) [ Time Frame: Baseline and Month 9. ] [ Designated as safety issue: No ]
  Severity of anorexia is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Anorexia Gastrointestinal Symptom (Month 12) [ Time Frame: Baseline and Month 12. ] [ Designated as safety issue: No ]
  Severity of anorexia is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Anorexia Gastrointestinal Symptom (Month 18) [ Time Frame: Baseline and Month 18. ] [ Designated as safety issue: No ]
  Severity of anorexia is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Hematemesis and Melena Gastrointestinal Symptom (Month 3) [ Time Frame: Baseline and Month 3. ] [ Designated as safety issue: No ]
  Severity of hematemesis and melena (blood stool, black stool, tarry stool) is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Hematemesis and Melena Gastrointestinal Symptom (Month 6) [ Time Frame: Baseline and Month 6. ] [ Designated as safety issue: No ]
  Severity of hematemesis and melena (blood stool, black stool, tarry stool) is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Hematemesis and Melena Gastrointestinal Symptom (Month 9) [ Time Frame: Baseline and Month 9. ] [ Designated as safety issue: No ]
  Severity of hematemesis and melena (blood stool, black stool, tarry stool) is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Hematemesis and Melena Gastrointestinal Symptom (Month 12) [ Time Frame: Baseline and Month 12. ] [ Designated as safety issue: No ]
  Severity of hematemesis and melena (blood stool, black stool, tarry stool) is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Change From Baseline in Severity of Hematemesis and Melena Gastrointestinal Symptom (Month 18) [ Time Frame: Baseline and Month 18. ] [ Designated as safety issue: No ]
  Severity of hematemesis and melena (blood stool, black stool, tarry stool) is graded on a 4 point scale (0=none; 1=mild; 2=moderate; 3=severe). Higher scores indicate greater severity of gastrointestinal symptom.
  
  
• Number of Participants With Adverse Events [ Time Frame: 18 Months ] [ Designated as safety issue: No ]
  Treatment-emergent adverse events (TEAE) are adverse events with an onset that occurs after receiving study drug. A TEAE may also be a concurrent medical condition diagnosed prior to the date of first dose of study drug that increases in severity after the start of dosing. Please see Other Adverse Events table below for TEAE listings.
  
  

In Japan, low-dose aspirin is one of the commonly prescribed drugs for inhibiting thrombosis and thrombus formation after angina, myocardial infarction, ischemic cerebrovascular disease, coronary artery by-pass surgery and percutaneous transluminal coronary angioplasty in patients. While low-dose aspirin is effective in these cases, its use sometimes causes gastric and duodenal ulcers which can lead to gastrointestinal bleeding, and in worse cases may lead to death.

The purpose of this study is to assess the efficacy of lansoprazole versus gefarnate in patients with a history of gastric or duodenal ulcers receiving daily low dose aspirin therapy.