Study of DIAG723, a New Antibody Treatment via Subcutaneous Injection in Adults with Hereditary Hemorrhagic Telangiectasia Including Those with Pulmonary Arterial Hypertension

What this Trial Is About

Researchers are studying DIAG723, a new antibody treatment, in adult patients with hereditary hemorrhagic telangiectasia HHT, including those with pulmonary arterial hypertension PAH. This first-in-human, randomized, double-blind, placebo-controlled Phase 12 study aims to evaluate the safety, tolerability, pharmacokinetics, and preliminary clinical effects of DIAG723. The study is conducted in three parts, each with different dosing strategies and patient groups. Part A involves single ascending doses of DIAG723 given by subcutaneous injection to sequential cohorts to assess safety and pharmacokinetics. Parts B and C involve multiple doses administered subcutaneously over approximately 13 weeks, with Part B including patients with HHT symptoms and Part C including patients with both HHT and PAH. Participants in all parts are randomly assigned to receive either DIAG723 or placebo. Safety committees oversee dose escalation and study progression. During the study, participants receive inpatient monitoring after dosing in Part A and outpatient follow-up in all parts. Assessments include safety evaluations, blood tests, electrocardiograms, pharmacokinetic sampling, and clinical measures such as changes in epistaxis frequency and blood parameters. Participants are followed for adverse events through specific time windows after dosing. The study duration varies by part but includes treatment periods of up to 13 weeks with additional follow-up visits.

DIAG723 in Adults With Hereditary Hemorrhagic Telangiectasia