Prospective phase 1/2 study of rituximab in childhood and adolescent chronic immune thrombocytopenic purpura.
We assessed safety and efficacy of rituximab in a prospective study of 36 patients, age 2.6 to 18.3 years, with severe chronic immune thrombocytopenic purpura (ITP). The primary outcome of sustained platelets above 50 x 10(9)/L (50,000/mm3) during 4 consecutive weeks, starting in weeks 9 to 12, was achieved by 11 of 36 patients (31%, confidence interval [CI], 16% to 48%). Median response time was 1 week (range, 1 to 7 weeks). Attainment of the primary outcome was not associated with age, prior pharmacologic responses, prior splenectomy, ITP duration, screening platelet count, refractoriness, or IgM reduction. First-dose, infusion-related toxicity was common (47%) despite premedication. Significant drug-related toxicities included third-dose hypotension (n = 1) and serum sickness (n = 2). Peripheral B cells were depleted in all subjects. IgM decreased 3.4% per week, but IgG did not significantly decrease. Rituximab was well tolerated, with manageable infusion-related side effects, but 6% of subjects developed serum sickness. Rituximab is beneficial for some pediatric patients with severe, chronic ITP.
Bennett
Carolyn M
CM
Division of Hematology/Oncology, Children's Hospital Boston, Boston, MA 02115, USA.
Rogers
Zora R
ZR
Kinnamon
Daniel D
DD
Bussel
James B
JB
Mahoney
Donald H
DH
Abshire
Thomas C
TC
Sawaf
Hadi
H
Moore
Theodore B
TB
Loh
Mignon L
ML
Glader
Bertil E
BE
McCarthy
Maggie C
MC
Mueller
Brigitta U
BU
Olson
Thomas A
TA
Lorenzana
Adonis N
AN
Mentzer
William C
WC
Buchanan
George R
GR
Feldman
Henry A
HA
Neufeld
Ellis J
EJ
D000293:Adolescent; D000911:Antibodies, Monoclonal / Q000627:therapeutic use* / Q000633:toxicity*; D058846:Antibodies, Monoclonal, Murine-Derived; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007022:Hypotension / Q000139:chemically induced; D007155:Immunologic Factors / Q000627:therapeutic use* / Q000633:toxicity*; D018579:Patient Selection; D011446:Prospective Studies; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000188:drug therapy*; D000069283:Rituximab; D012713:Serum Sickness / Q000139:chemically induced; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D007155:Immunologic Factors; D000069283:Rituximab