Long-term Effects of Thalidomide for Recurrent Gastrointestinal Bleeding Due to Vascular Malformation
Condition: Obscure Gastrointestinal Bleeding; Angiodysplasia; Gastric Antral Vascular Ectasia; Thalidomide
MeSH terms: Gastrointestinal Hemorrhage; Gastric Antral Vascular Ectasia; Vascular Malformations; Angiodysplasia; Congenital Abnormalities; Hemorrhage
Study type: Interventional
Phase: Phase 2

Summary: 
      Background: Repeated episodes of bleeding from gastrointestinal vascular malformations
      refractory to endoscopic or surgical therapy often pose a major therapeutic challenge.

      Methods: The investigators performed a randomized, parallel controlled study of thalidomide
      as a therapy for recurrent gastrointestinal bleeding due to vascular malformation. Patients
      with at least six episodes of bleeding in the prior year due to vascular malformation were
      randomly grouped, prescribed a four-month regimen of either 25 mg of thalidomide or 100 mg of
      iron orally four times daily, and monitored for at least one year. The primary end point was
      defined as the patients whose rebleeds decreased from baseline by ≥ 50% at 12 months and the
      cessation of bleeding. Rebleeding was defined based on a positive fecal occult blood test
      (FOBT) (monoclonal colloidal gold color technology) at any visit after treatment. Secondary
      outcomes included the participants dependent on blood transfusions and changes from baseline
      in transfused packed red cell units, bleeding episodes, bleeding durations, and hemoglobin
      levels at 12 months. Statistical significance was defined at P < 0.05.
    

Detailed description: 
      Protocol Description:

      This is an exploratory, randomized, parallel controlled study of thalidomide for recurrent
      gastrointestinal bleeding from vascular malformations. Informed consent was taken from all
      subjects and the Institute Ethics Committee approved the study protocol. All procedures were
      in accordance with the Declaration of Helsinki. The study was supported by no pharmaceutical
      funding.

      Study design and Intervention:

      From Nov. 2004 to Nov. 2007, patients with repeated episodes of chronic gastro-intestinal
      bleeding due to vascular malformations identified by oesophagogastroduodenoscopy, capsule
      endoscope or double-balloon endoscope were enrolled (according our enrollment criteria).

      The patients were randomly assigned to receive a four-month course of either 25 mg of
      thalidomide or 100mg iron orally at daily time 6 a.m.,12 noon,6 p.m. and 10 p.m.,
      respectively.

      Randomization was performed through the proc plan procedure of Statistical Analysis Software
      (SAS), using the method of randomly permuted blocks of 4. Within each block, the number of
      patients allocated to each of the two treatments was equal. Each patient who met the
      inclusion criteria was consecutively assigned a random number in chronological order, which
      allocated him or her to one of the treatment groups. A blinded research nurse supervised
      patient randomization and drug administration.

      In the case of an adverse event, the study medication was temporarily or permanently
      discontinued based on subject inclination and toxicity intolerance. Concomitant therapies,
      such as blood transfusions and other symptomatic treatments like iron supplementation, were
      performed in both groups as necessary during the four-month treatment and subsequent
      follow-up periods. Blood transfusion was indicated and recorded when the hemoglobin (Hb)
      level reached < 7.0 g/dl. Red-cell transfusions were administered according to patient Hb
      level as follows: 2 units were administered for 6.1 g/dl ≥ Hb ≤ 7.0 g/dl, 3 units for 5.1
      g/dl ≥ Hb ≤ 6.0 g/dl, and 4 units for Hb < 5.0 g/dl. Iron was provided for patients with 7.0
      g/dl ≥ Hb ≤ 11.0 g/dl. After the four-month treatment course, all patients discontinued study
      medications except for cases where symptomatic treatments were necessary as described above.

      Assessment of response and adverse events:

      The primary end point was defined as the patients whose rebleeds decreased from baseline by ≥
      50% at 12 months and the cessation of bleeding. Rebleeding was defined based on a positive
      fecal occult blood test (FOBT) (monoclonal colloidal gold color technology) at any visit
      after treatment. Secondary outcomes included the participants dependent on blood transfusions
      and changes from baseline in transfused packed red cell units, bleeding episodes, bleeding
      durations, and hemoglobin levels at 12 months.

      Adverse events included any unfavorable change in health, including abnormal laboratory
      findings, during the study or follow-up period.

      Evaluation of Patients and Follow-up:

        -  Certified research nurses collected information on the demographics and medical and
           social histories of all patients enrolled in the study.

        -  After screening and baseline evaluations, the patients were closely monitored in the
           hospital for at least one week. They were then followed twice monthly during the
           four-mouth course of treatment and once a month thereafter.

        -  Clinical follow-up was performed by qualified doctors. At all visits, the
           bleeding-related parameters (number and duration), a physical examination was performed
           and laboratory values were obtained for FOBT, complete blood counts, serum chemistries,
           and hepatic and renal function. Neuropathy and other adverse events were also assessed.

        -  Patients were advised to refrain from any other non-prescribed medicines, especially
           rebleeding-related medications such as aspirin, nonsteroidal antiinflammatory drugs
           (NSAIDs), anti-platelet drugs, anticoagulants, and Chinese medications (with
           salicylates), gingko, or Echinacea.

      Measurement of Vascular Endothelial Growth Factor (VEGF) in Sera:

      Laboratory assays for VEGF were performed at baseline and after the four-month treatment
      course in the thalidomide group, by a technician blinded to the assignment and final
      assessment. Three milliliters of serum of peripheral venous blood samples were centrifuged
      (3000 r/min at 4°C, 10 min), extracted, separated into freezing tubes, and stored at -70°C
      for no more than 4 months. Plasma VEGF levels (in pg/ml) were determined in duplicate using
      sandwich ELISA kits (R&D Systems, USA) in a laboratory of the Shanghai Research Institute of
      Digestive Disease. Samples from each patient were batch-tested in a single run. For quality
      control, all samples were retested two more times in a subsequent run to confirm the results
      of the first run.

      Statistical Analysis:

      To our knowledge, no similar such study has previously been performed, and we were thus
      unable to refer to published studies to determine our samples. To this end, we performed an
      unpublished preliminary study. Response in the iron-control group and thalidomide group
      reached 10% and 80%, due to loose inclusion criteria (bleeding history was not restricted).
      For this study, we estimated that the primary outcome (the proportion of subjects whose
      number of yearly bleeds had decreased by ≥ 50%) would occur in 10% of the control group and
      80% of the thalidomide group patients. An equally divided sample of 11 subjects was deemed
      sufficient for detecting the primary end point, with a type I error (two-sided) of 5% and a
      power of 90%. Assuming a 10% volunteer attrition rate to follow-up, we established a target
      sample size of 13 per group (calculated with nquery advisor software 5.0).

      Analyses of the responses and adverse events were performed on all registered patients
      according to the intention-to-treat principle. Statistical analysis was performed by a
      blinded biostatistician with the Statistical Product and Service Solutions (SPSS) 13.0
      software package. We simultaneously analyzed the primary endpoint of the full analysis set
      (FAS) and per protocol set (PPS). Continuous variables were compared using a two-sample
      independent t-test or Wilcoxon rank-sum test. Categorical variables were compared using the
      chi-squared and Fisher's exact tests. A paired t-test was employed to compare differences in
      plasma VEGF levels before and after thalidomide treatment. The Breslow-Day test was used to
      test for the heterogeneity of treatment effects across strata. All reported P-values are
      two-sided. Data are reported as the mean ± standard deviation (SD) or median (range) for
      continuous variables and number (%) for categorical variables. Since adjustments to the
      control group were minimal, we also reported point estimates and 95% confidence intervals
      (CIs). For all outcomes, a P-value of < 0.05 was considered statistically significant.
    

Intervention name(s): Thalidomide; Iron
Intervention type(s): Drug; Drug
Intervention description(s): Patients were randomly assigned to receive a four-month course of 25 mg of thalidomide (Pharmaceutical Co., Ltd. of Chang-zhou, China). Medications were taken orally four times daily at 6 a.m., 12 noon, 6 p.m., and 10 p.m.; Patients were randomly assigned to receive a four-month course of 100 mg of iron (Pharmaceutical Co., Ltd. of Nanjing, China). Medications were taken orally four times daily at 6 a.m., 12 noon, 6 p.m., and 10 p.m.
Other intervention name(s): Softenon;; Ferrous Succinate Tablets
Intervention MeSH terms: Thalidomide; Ferrous succinate
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: vascular malformation; gastrointestinal bleeding; thalidomide