Ablynx, a Sanofi Company, has developed the anti-von Willebrand factor Nanobody® 
caplacizumab (Cablivi™) for the treatment of acquired thrombotic 
thrombocytopenic purpura (aTTP). Based on positive results in phase II and III 
trials in patients with aTTP, caplacizumab was recently approved in the EU for 
the treatment of adults experiencing an episode of aTTP, in conjunction with 
plasma exchange and immunosuppression. This article summarizes the milestones in 
the development of caplacizumab leading to this first approval.