Rozrolimupab, a mixture of 25 recombinant human monoclonal RhD antibodies, in the treatment of primary immune thrombocytopenia

Clinical updates in adult immune thrombocytopenia

“…78 Several novel therapies are on the horizon for the management of ITP, and other immunosuppressive medications have been studied in small cohorts of patients. 79 These therapies include antibodies targeting the CD40-CD154 interaction between B and T cells, 80,81 treatments targeting the Fc receptor 82 and the neonatal Fc receptor, targeting downstream signaling after crosslinking of receptors caused by antibody binding (Syk kinase in particular), 83 and novel agents to increase platelet production, including new thrombopoietin receptor agonists and amifostine. 84,85 For patients who fail conventional first-or secondline therapies, there are novel therapies in development and under study based on our improving understanding of the pathophysiology of this complex disease.…”

Are 25 antibodies better than 1?

“…2 In a phase 1/2 dose escalation study, rozrolimupab was administered as a single dose of 75 to 300 g/kg to 61 nonsplenectomized, RhD-positive adults with primary ITP. 1 Treatment was generally well tolerated. The most common adverse events, headache and infusion reactions, were predominantly mild and transient.…”

“…1 P lasma-derived anti-RhD, a hyperimmune preparation of IgG that targets the RhD antigen on erythrocytes, is a standard first-line therapy in nonsplenectomized RhDpositive individuals with immune thrombocytopenia (ITP), and is also used to prevent maternal RhD-sensitization and hemolytic disease of the newborn. The primary mechanism of action in ITP is thought to involve opsonization of endogenous RhD-positive red blood cells (RBCs), resulting in preferential clearance of antibody-coated RBCs by the reticuloendothelial system and sparing of antibody-coated platelets.…”

Monoclonal versus polyclonal anti-D in the treatment of ITP

“…This therapeutic was tested in a phase I/II dose escalation study in adult patients with primary ITP [15]. The product was reasonably well tolerated in most patients and it significantly elevated platelet counts in a clear majority of patients at higher dosages [14][15][16]. The success of this new recombinant reagent demonstrates that good therapeutic efficacy can be obtained in ITP with, at the very least, a monoclonal antibody blend.…”

“…This new product is called Rozrolimupab and is comprised of 25 recombinant human IgG1 antibodies derived from eight different individuals recognizing multiple epitopes on the RhD antigen. This therapeutic was tested in a phase I/II dose escalation study in adult patients with primary ITP [15]. The product was reasonably well tolerated in most patients and it significantly elevated platelet counts in a clear majority of patients at higher dosages [14][15][16].…”