Caplacizumab — Drug Monograph

Brand names: Cablivi

Drug class: Monoclonal Antibody

Mechanism of Action

Humanized bivalent single-domain antibody (nanobody) that binds the A1 domain of von Willebrand factor (vWF), blocking the interaction between ultra-large vWF multimers and platelet glycoprotein Ib-IX-V. This prevents vWF-mediated platelet adhesion and the microthrombus formation that drives acquired thrombotic thrombocytopenic purpura (aTTP), rapidly protecting the microvasculature while immunosuppression restores ADAMTS13.

FDA Indications

• Acquired (immune) thrombotic thrombocytopenic purpura (aTTP) in adults, in combination with plasma exchange and immunosuppressive therapy (FDA approved 2019)

Common Side Effects

• Epistaxis
• Gingival bleeding
• Bruising / injection-site bleeding
• Headache
• Fatigue

Clinical Pearl

Caplacizumab is the first agent that directly interrupts the platelet–vWF interaction driving TTP microthrombosis, and when added to plasma exchange plus immunosuppression it speeds platelet recovery and reduces TTP-related death, refractoriness, and recurrence (HERCULES trial). Because it is fundamentally an antithrombotic, its main hazard is bleeding — hold it around invasive procedures. It treats the acute clotting; it does not replace immunosuppression to restore ADAMTS13.

Related Therapies & Mechanisms

• Eculizumab (Soliris) — Monoclonal Antibody · Supportive Care
• Pozelimab (Veopoz) — Monoclonal Antibody · Supportive Care
• Ravulizumab (Ultomiris) — Monoclonal Antibody · Supportive Care
• Alemtuzumab (Campath) — Monoclonal Antibody