Therapeutic switch from plasma to recombinant ADAMTS13 for patients with congenital TTP from Japanese real-world data

Congenital thrombotic thrombocytopenic purpura (cTTP) is an ultrarare disorder characterized by thrombocytopenia, microangiopathic hemolytic anemia, and ischemic organ damage caused by pathogenic ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13) variants. ADAMTS13-containing product, including fresh-frozen plasma (FFP), and plasma-derived factor VIII concentrates are commonly used to supply ADAMTS13; however, frequent hospital visits and allergic reactions are major drawbacks. A recombinant ADAMTS13 (rADAMTS13) was recently developed to address these issues. However, real-world evidence has not been reported owing to the rarity of this condition. This study compared the efficacy and safety of FFP and rADAMTS13 in 14 Japanese patients, including 5 patients with end-stage renal disease who were excluded from the phase 3 trial. The median peak level of ADAMTS13 activity 15 minutes after rADAMTS13 administration was significantly higher than that after FFP (68.4% vs 15.9%; P < .001). ADAMTS13 activity 1 week after rADAMTS13 administration was well maintained compared with FFP infusion (11.6% vs 5.1%; P < .001). Patients reported no allergic reactions after rADAMTS13 administration and appreciated the convenience of a single infusion of rADAMTS13, suggesting that rADAMTS13 is a safe and effective alternative to FFP in patients with cTTP. To our knowledge, this is the first publication of patients with cTTP who switched FFP to novel rADAMTS13 from Japanese real-world data.