Outcomes 5 years after response to rituximab therapy in children and adults with immune thrombocytopenia

• Published in: Blood 2012-06, Vol.119 (25), p.5989-5995
• Main Authors: Patel, Vivek L., Mahévas, Matthieu, Lee, Soo Y., Stasi, Roberto, Cunningham-Rundles, Susanna, Godeau, Bertrand, Kanter, Julie, Neufeld, Ellis, Taube, Tillmann, Ramenghi, Ugo, Shenoy, Shalini, Ward, Mary J., Mihatov, Nino, Patel, Vinay L., Bierling, Philippe, Lesser, Martin, Cooper, Nichola, Bussel, James B.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Antibodies, Monoclonal, Murine-Derived - therapeutic use; Biological and medical sciences; Child; Child, Preschool; Clinical Trials and Observations; Female; Follow-Up Studies; Hematologic and hematopoietic diseases; Humans; Immunologic Factors - therapeutic use; Immunotherapy - methods; Male; Medical sciences; Middle Aged; Models, Biological; Platelet diseases and coagulopathies; Platelets and Thrombopoiesis; Purpura, Thrombocytopenic, Idiopathic - therapy; Rituximab; Time Factors; Treatment Outcome; Young Adult
• ISSN: 0006-4971; 1528-0020; 1528-0020
• DOI: 10.1182/blood-2011-11-393975

Treatments for immune thrombocytopenic purpura (ITP) providing durable platelet responses without continued dosing are limited. Whereas complete responses (CRs) to B-cell depletion in ITP usually last for 1 year in adults, partial responses (PRs) are less durable. Comparable data do not exist for children and 5-year outcomes are unavailable. Patients with ITP treated with rituximab who achieved CRs and PRs (platelets > 150 × 109/L or 50-150 × 109/L, respectively) were selected to be assessed for duration of their response; 72 adults whose response lasted at least 1 year and 66 children with response of any duration were included. Patients had baseline platelet counts < 30 × 109/L; 95% had ITP of > 6 months in duration. Adults and children each had initial overall response rates of 57% and similar 5-year estimates of persisting response (21% and 26%, respectively). Children did not relapse after 2 years from initial treatment whereas adults did. Initial CR and prolonged B-cell depletion predicted sustained responses whereas prior splenectomy, age, sex, and duration of ITP did not. No novel or substantial long-term clinical toxicity was observed. In summary, 21% to 26% of adults and children with chronic ITP treated with standard-dose rituximab maintained a treatment-free response for at least 5 years without major toxicity. These results can inform clinical decision-making.