From the FDA Drug Label
- 1 Pregnancy Risk Summary There are no available data on CABLIVI use in pregnant women to inform a drug-associated risk of major birth defects and miscarriage. However, there are potential risks of hemorrhage in the mother and fetus associated with use of CABLIVI
The use of caplacizumab in pregnancy is not well-studied, and there are potential risks of hemorrhage in the mother and fetus. Due to the lack of data, caution should be exercised when considering caplacizumab use in pregnant women.
- Monitor neonates for bleeding
- Pregnant women receiving caplacizumab should be carefully monitored for evidence of excessive bleeding 1
From the Research
Caplacizumab should be considered for use in pregnancy-related acquired thrombotic thrombocytopenic purpura (aTTP) when the potential benefit justifies the risk to the fetus, as evidenced by a recent case study published in the British Journal of Haematology in 2023 2.
Key Considerations
- Caplacizumab is a nanobody that targets von Willebrand factor and is used to treat aTTP, a rare but life-threatening condition.
- The standard dosing regimen involves an initial 10 mg intravenous dose followed by 10 mg subcutaneous doses daily during plasma exchange and for 30 days after stopping plasma exchange, with possible extension based on risk factors.
- For pregnant women with aTTP, treatment decisions should be made on a case-by-case basis, weighing the serious maternal risks of untreated aTTP against potential fetal risks.
- Animal studies have not shown evidence of harm to the fetus, but human data is scarce, as noted in a study published in Blood Coagulation & Fibrinolysis in 2023 3.
Clinical Evidence
- A recent study published in the British Journal of Haematology in 2023 2 described the successful use of caplacizumab in a pregnant patient with acquired TTP, resulting in hematologic recovery and successful delivery of a healthy neonate.
- Another study published in Acta Haematologica in 2022 4 reported the effectiveness of caplacizumab in a patient with aTTP refractory to conventional treatment, including plasma exchange and corticosteroids.
Monitoring and Safety
- If caplacizumab is used during pregnancy, close monitoring of both mother and fetus by a multidisciplinary team including hematologists and maternal-fetal medicine specialists is essential, as emphasized in a commentary published in the British Journal of Haematology in 2023 5.
- The drug works by inhibiting the interaction between von Willebrand factor and platelets, preventing the formation of microthrombi that characterize aTTP, which may be particularly important in pregnancy when aTTP can have severe consequences for both mother and fetus.