Advances in the treatment of thrombotic thrombocytopenic purpura: repurposed drugs and novel agents

Introduction: Thrombotic thrombocytopenic purpura (TTP) is an infrequent but fatal disease. Plasma exchange and corticosteroids continue to be the mainstay of treatment; however, repurposed drugs and novel agents are emerging as efficient treatment options. Areas covered: In this review, new therapeutic developments in immune-mediated TTP including rituximab, bortezomib, N-acetylcysteine, caplacizumab, and recombinant ADAMTS13, among others, are summarized. Expert opinion: Evidence on the use of rituximab in first and second-line settings is accumulating showing promising potential for avoiding relapses in patients in remission but with low circulating levels of ADAMTS13 in a preemptive fashion. Other repurposed drugs such as bortezomib and N-acetylcysteine are increasingly used off-label. Recombinant ADAMTS13 is slowly emerging. Caplacizumab, a humanized anti-von Willebrand factor-directed nanobody that blocks platelet adhesion and avoids microthrombi formation, was approved by regulatory agencies based on the positive results of a phase-III clinical trial, adding a new drug to the therapeutic arsenal in TTP.