Retreatment and Its Efficiency of Thalidomide for Vascular Malformation Patients With Failure of First Course Treatment

Background: Repeated episodes of bleeding from gastrointestinal vascular malformations refractory to endoscopic or surgical therapy often pose a major therapeutic challenge. Methods: The investigators will perform a randomized, double blind, placebo controlled study of thalidomide as a retreatment therapy for recurrent gastrointestinal bleeding due to vascular malformation. Patients with failure of first course treatment of thalidomide will be randomly grouped, prescribed a second four-month course regimen of 25 mg of thalidomide or placebo orally four times daily. All patients will be monitored for at least one year. The primary end point is defined as the patients whose rebleeds decrease from baseline by ≥ 50% at 12 months and the cessation of bleeding. Rebleeding is defined based on a positive fecal occult blood test (FOBT) (monoclonal colloidal gold color technology) at any visit after treatment. Secondary outcomes include the participants dependent on blood transfusions and changes from baseline in transfused packed red cell units, bleeding episodes, and hemoglobin levels at 12 months. Statistical significance is defined at P \< 0.05.