Pomalidomide for the Treatment of Bleeding in Hereditary Hemorrhagic Telangiectasia Longitudinal Assessment Study

This is a multicenter U.S. longitudinal study evaluating patients with hereditary hemorrhagic telangiectasia who participated in the PATH-HHT clinical trial of pomalidomide for the treatment of HHT. This study is a longitudinal assessment of safety and effectiveness of pomalidomide in HHT in clinical trial participants following completion of the double-blind, placebo-controlled study.

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant condition characterized by disordered angiogenesis that affects 1 in 5,000 people. It results in numerous clinical complications including severe recurrent epistaxis, gastrointestinal bleeding, chronic iron deficiency anemia (and possible transfusion dependence), high-output cardiac failure, and many others. In recognition that elevated levels of vascular endothelial growth factor (VEGF) are elevated in HHT, anti-angiogenic drugs are now being used to treat HHT off-label to manage HHT-associated bleeding. A primary agent used for this purpose is pomalidomide, an oral immunomodulatory drug with antiangiogenic properties. Pomalidomide was demonstrated to be efficacious over a 6-month treatment period in the multicenter U.S. randomized controlled PATH-HHT Study. The present study is the successor to PATH-HHT, the PATH-HHT ATLAS (After Trial Longitudinal Assessment Study). This study will evaluate the long-term impact of pomalidomide on epistaxis (as measured by the validated ESS, epistaxis severity score), gastrointestinal bleeding, and iron deficiency anemia (as assessed by hemoglobin measurements, red blood cell transfusions, and intravenous iron infusions).