Evaluation of Pazopanib on Bleeding in Subjects With Hereditary Haemorrhagic Telangiectasia

This study will investigate whether pazopanib can reduce epistaxis and improve anaemia in subjects with hereditary haemorrhagic telangiectasia (HHT) at a dose that is well tolerated. The study will have 2 parts. Part A will be an open label, dose-escalation study in which up to 4 cohorts of approximately 6 subjects each will receive increasing doses of pazopanib for a maximum of 12 weeks. The dose in the first cohort will be 50mg per day and the maximum dose in a cohort will be 400 mg per day. Dose escalation will not occur as planned if the predefined safety stopping criteria are met or at least 4 subjects in a cohort have demonstrated efficacy (as measured by epistaxis, haemoglobin, transfusion or iron infusion requirements). If efficacy is demonstrated in Part A with an acceptable safety profile, Part B will be initiated to further define the optimal dose(s) including dose duration/schedule and to provide further support for the proof of mechanism. Approximately 15 subjects will participate and will be randomised to active or placebo in a ratio of 3:2. This part of the study will be double-blind.