Bevacizumab In Hereditary Hemorrhagic Telangiectasia

Inclusion Criteria * A clinical diagnosis of "possible/suspected" or "definite" hereditary hemorrhagic telangiectasia, as defined by presence of 2 or more of the Curacao criteria (spontaneous and recurrent epistaxis, telangiectasias at characteristic sites, visceral arteriovenous malformations (AVMs), first degree relative with HHT). * Age ≥18 years. Because no dosing or adverse event data are currently available on the use of bevacizumab for HHT in participants \<18 years of age, children are excluded from this study, but will be eligible for future pediatric trials. * Red blood cell transfusion and/or iron infusion dependence, as defined by a hematologic support score (HSS) of ≥3 in the 3 months prior to consent. HSS is calculated by dividing the total milligrams of elemental iron infused by 250 and adding to this the number of red cell units transfused. * ECOG performance status ≤2 (see Appendix B). * Participants must have adequate organ and marrow function as defined below: * leukocytes ≥2,000/mcL * absolute neutrophil count ≥1,000/mcL * platelets ≥50,000/mcL * AST(SGOT)/ALT(SGPT) ≤3 × institutional ULN\* * creatinine ≤ 2.5 mg/dL OR * glomerular filtration rate (GFR) ≥45 mL/min/1.73 m2 \*Except AST and/or ALT elevation related to HHT-associated hemolytic anemia or liver AVMs, in the opinion of the investigator. Bilirubin thresholds are not included as mild chronic hyperbilirubinemia is common in HHT, likely related to subclinical hemolysis in AVMs. Patients…