A safe and effective use of caplacizumab in pregnancy-related acquired thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) is not uncommonly seen in pregnancy, either with the first episode or with the exacerbation of known disease. The management of TTP in pregnancy can be challenging if there is refractoriness to the use of therapeutic plasma exchange (TPE) and high-dose corticosteroids. Caplacizumab, a vWF-directed humanized antibody fragment, is approved for the treatment of acquired TTP but there is sparse data on its use in pregnant patients. Antenatal and peripartum haemorrhage is a theoretical concern with the use of the medication in the obstetric population. However, as options for treatment of TTP in the patients who have refractory disease are significantly limited, off-label use of caplacizumab to achieve disease control and prevent maternofetal morbidity and mortality is a reasonable consideration. This article described the successful use of caplacizumab in a pregnant patient with acquired TTP and the associated favourable outcome. The patient suffered an exacerbation following initial TPE and became refractory to both plasma exchange and high-dose corticosteroids. Off-label use of caplacizumab resulted in hematologic recovery and successful delivery of a healthy neonate. This case represents a contribution to the sparse literature on the use of this effective medication in an often-challenging clinical situation.