Blood Journal
Leading the way in experimental and clinical research in hematology

Outcome at 5 years following response to rituximab therapy in children and adults with immune thrombocytopenia (ITP)

  1. Vivek L. Patel1,*,
  2. Matthieu Mahévas2,
  3. Soo Y. Lee1,
  4. Roberto Stasi3,
  5. Susanna Cunningham-Rundles1,
  6. Bertrand Godeau2,
  7. Julie Kanter4,
  8. Ellis Neufeld5,
  9. Tillmann Taube6,
  10. Ugo Ramenghi7,
  11. Shalini Shenoy4,
  12. Mary J. Ward1,
  13. Nino Mihatov1,
  14. Vinay L. Patel1,
  15. Philippe Bierling2,
  16. Martin Lesser8,
  17. Nichola Cooper9, and
  18. James B. Bussel1
  1. 1 Department of Pediatrics, Division of Hematology/Oncology, Platelet Disorders Research and Treatment Program, Weill Medical College of Cornell University, New York, New York, United States;
  2. 2 Medecine Interne, Hopital Henri Mondor, Assistance Publique Hopitaux de Paris, Universite Paris Est, Creteil, France;
  3. 3 Department of Medical Sciences, Ospedale 'Regina Apostolorum", Albano Laziale, Italy;
  4. 4 Pediatric Hematology/Oncology, Washington University School of Medicine, St. Louis, Missouri, United States;
  5. 5 Division of Hematology/Oncology, Children's Hospital, Boston, Massachusetts, United States;
  6. 6 Department of Pediatric Oncology/Hematology, Charite University Hospital, Berlin, Germany;
  7. 7 Hematology Unit, Pediatric Department, University of Torino, Torino, Italy;
  8. 8 Biostatistics Unit, Feinstein Institute for Medical Research, North Shore University Hospital, Manhasset, New York, United States;
  9. 9 Department of Haematology, Hammersmith Hospital, Imperial Healthcare NHS Trust, London, United Kingdom
  1. * Corresponding author; email: vivek.patel{at}med.einstein.yu.edu

Abstract

Treatments for ITP providing durable platelet responses without continued dosing are limited. Whereas complete-responses (CR) to B-cell depletion in ITP usually last for one year in adults, partial-responses (PR) 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 >150x109/l or 50-150x109/l, respectively) were selected to be assessed for duration of their response; 72 adults whose response lasted at least one year and 66 children with response of any duration were included. Patients had baseline platelet counts <30x109/l; 95% had ITP of greater than 6-months duration. Adults and children each had initial overall response rates of 57% and similar five-year estimates of persisting response (21% and 26% respectively). Children did not relapse after two 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, 21-26% of adults and children with chronic ITP treated with standard-dose rituximab maintained a treatment-free response for at least five years without major toxicity. These results can inform clinical decision-making.

  • Submitted November 25, 2011.
  • Accepted April 16, 2012.