The impact of caplacizumab in the treatment of immune thrombotic thrombocytopenic purpura. A retrospective monocentric cohort study

Le résumé fourni par la source

Background: Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare, life-threatening disorder caused by severe ADAMTS13 deficiency, leading to microvascular platelet-rich thrombi, hemolysis, and organ damage, mainly involving brain, heart, kidneys, and intestines. Standard treatment includes plasma exchange (PEX) and immunosuppressants. Caplacizumab (CAPLA), an anti-von Willebrand factor nanobody, was recently introduced into clinical practice. Methods: We retrospectively analyzed 81 patients diagnosed with iTTP at our center from 1990 to 2024, accounting for 165 acute episodes requiring treatment. We compared outcomes between episodes treated with standard of care (SOC) and those with CAPLA, evaluating number of PEX sessions to platelet normalization, hospitalization length, CAPLA use, and disease stage (new onset vs. relapse). CAPLA was administered from episode onset until 30 days after PEX suspension. Results: Median age at first episode was 39.9 years (range 13-75), with 63% female patients. Over a median follow-up of 6.4 years, 47 patients (58%) experienced at least one relapse (range 1-7), all treated with PEX and corticosteroids. Of the 165 episodes, 39 (25.5%) were treated with CAPLA, 126 (74.5%) with SOC. Baseline characteristics were similar. Median PEX sessions were significantly lower in the CAPLA group (6 vs. 9.5; p < 0.0001), as were hospitalization days (8 vs. 13.5; p < 0.0001). Exacerbation after PEX occurred in 11 patients, more frequently in the CAPLA group (13% vs. 5%), associated with higher inhibitor levels (66 U/mL). Interestingly, patients who relapsed later had lower inhibitor levels at baseline (34 vs. 63 U/mL; p = 0.045) but longer hospital stays (12 vs. 10 days; p = 0.03), possibly due to less frequent CAPLA use (18% vs. 30%). Conclusion: Caplacizumab significantly reduces PEX sessions and hospitalization duration, leading to faster clinical response, regardless of disease stage or inhibitor level. However, its use may be linked to a higher rate of exacerbation, potentially due to earlier PEX discontinuation.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.