Long‐term follow‐up of patients with congenital thrombotic thrombocytopenia purpura receiving a plasma‐derived factor VIII (Koate) that contains ADAMTS13

• Published in: Haemophilia : the official journal of the World Federation of Hemophilia Vol. 29; no. 6; pp. 1638 - 1645
• Main Authors: Chrisentery‐Singleton, Tammuella, Boggio, Lisa N., Carcao, Manuel D., Ibrahimi, Sami, Khan, Osman, Mahajerin, Arash, Rajasekhar, Anita, Sharma, Vivek, Steele, MacGregor, Torres, Marcela, Rodino, Frank J., Carpenter, Shannon L.
• Format: Journal Article
• Language: English
• Published: Chichester Wiley Subscription Services, Inc 01.11.2023
• Subjects: ADAMTS13 protein; Caregivers; Coagulation factors; congenital thrombotic thrombocytopenic; Disease prevention; factor VIII/administration and dosage; Metalloproteinase; microangiopathic haemolytic anaemia; paediatric; Prophylaxis; Purpura; Thrombocytopenia; Upshaw–Schulman syndrome; Von Willebrand factor; von Willebrand factor‐cleaving protease
• ISSN: 1351-8216; 1365-2516
• DOI: 10.1111/hae.14891

Background Hereditary thrombotic thrombocytopenia purpura (hTTP) is an ultra‐rare disorder resulting from an inherited deficiency of ADAMTS13, a von Willebrand factor (VWF)‐cleaving metalloprotease. The plasma‐derived factor VIII/VWF Koate (FVIII/VWFKoate) has been shown to contain ADAMTS13, allowing for its use to treat hTTP at home by the patient/caregiver. Aim Based on prior demonstration of safe and effective use of FVIII/VWFKoate in eight patients with hTTP, we conducted a retrospective study to gather additional data regarding the use of FVIII/VWFKoate for hTTP. Methods This was a multicentre, retrospective, noninterventional chart review of patients who had received FVIII/VWFKoate for the management of hTTP. Data collected included demographics, medical history, relevant family history, past use and tolerability of fresh frozen plasma, and details regarding FVIII/VWFKoate therapy. Results The cohort included 11 patients (seven males, four females) with hTTP, ranging in age at study entry from 2 to 28 years. The average duration of FVIII/VWFKoate therapy was 4.8 years (range, 0.5–6.5 years). Among nine patients using FVIII/VWFKoate as prophylaxis, the normalized annual rate of breakthrough TTP episodes ranged from 0.2 to 1.1 episodes/year. All nine patients who received FVIII/VWFKoate prophylaxis had thrombocytopenia recorded at baseline, while eight (88.9%) did not have thrombocytopenia after using FVIII/VWFKoate. There was one AE (unspecified) attributed to FVIII/VWFKoate. Conclusion These data suggest that FVIII/VWFKoate is a safe and well‐tolerated source of the missing ADAMTS13 enzyme in patients with hTTP, producing a marked reduction in thrombocytopenia prevalence, low frequency of TTP episodes, and with the added benefit of self‐ or caregiver‐administration.