Caplacizumab-Enabled Treatment of Immune-Mediated Thrombotic Thrombocytopenic Purpura Without Plasma Exchange: Evidence, Patient Selection, and Practical Considerations.

BackgroundImmune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare, life-threatening autoimmune condition driven by severe ADAMTS13 deficiency. Therapeutic plasma exchange (TPE) is the traditional cornerstone of acute therapy, as it clears autoantibodies and replenishes functional ADAMTS13. However, caplacizumab-an anti-von Willebrand factor nanobody that rapidly blocks platelet-von Willebrand factor interactions-has raised the possibility of safely omitting TPE in carefully selected patients.ObjectiveTo review the biological rationale, current clinical evidence, patient-selection criteria, safety profile, and practical implementation of utilizing caplacizumab for iTTP treatment without relying on plasma exchange.MethodsA comprehensive narrative review was conducted. It analyzed published case reports, case series, registry data, comparative cohort studies, and guideline-relevant literature focusing on TPE-free or TPE-sparing caplacizumab-based regimens for iTTP.ResultsEvidence has evolved from isolated, necessity-driven cases to robust multicenter comparative data. Caplacizumab-based, TPE-free treatment combined with immunosuppression consistently drives rapid platelet recovery, typically within three to five days. Large comparative cohorts demonstrate that clinical response, exacerbation rates, refractoriness, and mortality are similar to conventional TPE-based therapies. Furthermore, the TPE-free approach offers the benefits of shorter hospital stays and reduced intensive care utilization. However, a subset of patients with inadequate initial platelet responses or complex comorbidities still required rescue TPE.ConclusionTPE-free caplacizumab therapy is a promising, highly targeted strategy, though it should not replace standard therapy outside experienced centers. Safe implementation demands confirmed iTTP, clinical stability, immediate caplacizumab availability, rigorous ADAMTS13 monitoring, adequate immunosuppression, and predefined thresholds for rescue TPE.