Systemic Bevacizumab for Severe Bleeding From Acquired Gastrointestinal Vascular Malformations

Acquired gastrointestinal vascular malformations not due to congenital disorders such as hereditary hemorrhagic telangiectasia are a common cause of chronic and acute hemorrhage, particularly in older adults. These lesions cause severe anemia, dependence on intravenous iron and/or red-cell transfusion, and recurring hospitalizations. Hemostatic procedures are temporizing and no standard treatment, including the somatostatin analogs, addresses the underlying angiogenic dysregulation driving vascular malformation formation and recurrence. Therefore, bevacizumab, an anti-VEGF-A monoclonal antibody, is a promising targeted therapeutic. In this observational cohort study, we analyzed 32 patients (median age 75 years, 44% female) with acquired gastrointestinal vascular malformations due to idiopathic angiodysplasia, chronic liver disease, or deficiencies of von Willebrand factor who were treated on a predefined institutional bevacizumab pathway. The median Hematologic Support Score (a composite endpoint integrating red-cell units transfused and elemental iron infused) improved from 15.04 (95% CI, 11.16-21.80) red-cell unit equivalents during 6 months pretreatment to 4.08 (4.00-8.00) during Months 1-6 of bevacizumab treatment (p < 0.001) and further to 0.00 (0.00-5.40) during months 7-12 (p < 0.001). Units of red cells transfused and quantity of elemental iron infused were analyzed independently; both significantly improved after bevacizumab initiation. Annualized hospitalization/ED visit rate improved from 3 (year before bevacizumab) to 1 (year after bevacizumab) (p = 0.01), and median hemoglobin improved by 3.1 g/dL after bevacizumab (p < 0.001). Proteinuria and hypertension occurred in 8 (25%) and 5 (16%) patients, respectively, leading to bevacizumab discontinuation in 3 (9%). In conclusion, bevacizumab is a novel, targeted therapeutic approach for acquired gastrointestinal vascular malformations that may be safe and effective.