Phase 3 Study of Mezagitamab Injections Under the Skin to Treat Adults with Chronic Primary Immune Thrombocytopenia

What this Trial Is About

Primary immune thrombocytopenia ITP is a condition where the immune system mistakenly destroys platelets, the cells responsible for blood clotting, resulting in increased bleeding and bruising. This trial evaluates whether mezagitamab given as a subcutaneous injection can effectively maintain stable platelet counts in adults with chronic ITP compared to a placebo. The study is a phase 3, randomized, double-blind, placebo-controlled trial designed to assess both the efficacy and safety of mezagitamab in this population. Participants are randomly assigned to receive either mezagitamab or a matching placebo by subcutaneous injection once weekly. The treatment schedule consists of 8 weekly doses followed by an 8-week break, then another 8 weekly doses, totaling up to 6 months of treatment. Those who finish this trial or do not respond to treatment by week 16 may have the option to join a continuation study to receive open-label mezagitamab if eligible and if the site is open. During the study, participants will visit the clinic multiple times for treatment and monitoring. Researchers will measure platelet responses, symptom changes using patient questionnaires, bleeding events, and blood concentrations of mezagitamab. Safety assessments include monitoring for anti-drug antibodies and adverse events. The primary outcome is the percentage of participants with a durable platelet response up to week 24. The trial is expected to complete in March 2028.

A Study of Mezagitamab in Adults With Chronic Primary Immune Thrombocytopenia