A phase 2 trial reported that mezagitamab, an investigational antibody, significantly increased platelet counts in patients with immune thrombocytopenia (ITP). ITP is driven by immune-mediated platelet destruction and impaired production, and clinicians typically need durable platelet response to reduce bleeding risk. The reported results position mezagitamab as a candidate for additional late-stage evaluation, with the main focus on both efficacy—platelet count improvement—and tolerability. For the broader ITP market, the readout adds another mechanism contender as antibodies with rapid platelet effects compete for differentiation in an area where response durability is a key unmet need.