title: Low-dose rituximab in adult patients with primary immune thrombocytopenia.
abstract: BACKGROUND
  Rituximab 375 mg/m(2) weekly for 4 wks has significant activity in adults with primary immune thrombocytopenia (ITP). In this setting, several evidences support the possible use of lower doses of rituximab.
  
  
  OBJECTIVE
  To investigate the activity of low-dose rituximab as salvage therapy in previously treated symptomatic ITP.
  
  
  METHODS
  Forty-eight adult patients were treated prospectively with rituximab 100 mg weekly for 4 wks.
  
  
  RESULTS
  Overall and complete responses (CR) (platelet level ≥ 50 and 100 × 10(9) /L) were 60.5% and 39.5%, respectively. In responders, the median time to response was 35 d (range: 7-112 d). The median time of observation was 18 months (range 3-49 months). Sixteen of 29 responding patients (55%) relapsed and 14 needed further treatments. The 12- and 24-month cumulative relapse-free survival was 61% and 45%, respectively. In univariate analysis, CR rate was in inverse relation with weight OR=0.95, CI(95%) [0.91; 0.99] (P=0.019) and age OR=0.96, CI(95%) [0.93; 0.99] (P=0.047). Cox regression model showed that relapse probability increases as weight (HR=1.06, CI(95%) [1.0031; 1.111]) and period between diagnosis and rituximab therapy (HR=1.01, CI(95%) [1.002; 1.017]) increase. One patient developed an interstitial pneumonia 1 month after the end of rituximab treatment. No other infectious, hematologic or extra-hematologic complications were documented during follow-up.
  
  
  CONCLUSIONS
  Low-dose rituximab is active in ITP but has moderate long-term effect. A comparative study with standard dose is warranted.
authors.affiliation: Clinica Ematologica, DIRM, Azienda Ospedaliero Universitaria S. Maria Misericordia, Udine, Italy. zaja.francesco@aoud.sanita.fvg.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Zaja
authors.forename: Nicola
authors.initials: N
authors.lastname: Vianelli
authors.forename: Stefano
authors.initials: S
authors.lastname: Volpetti
authors.forename: Marta Lisa
authors.initials: ML
authors.lastname: Battista
authors.forename: Marzia
authors.initials: M
authors.lastname: Defina
authors.forename: Salvatore
authors.initials: S
authors.lastname: Palmieri
authors.forename: Monica
authors.initials: M
authors.lastname: Bocchia
authors.forename: Marta
authors.initials: M
authors.lastname: Medeot
authors.forename: Stefano
authors.initials: S
authors.lastname: De Luca
authors.forename: Felicetto
authors.initials: F
authors.lastname: Ferrara
authors.forename: Miriam
authors.initials: M
authors.lastname: Isola
authors.forename: Michele
authors.initials: M
authors.lastname: Baccarani
authors.forename: Renato
authors.initials: R
authors.lastname: Fanin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000009:adverse effects; D058846:Antibodies, Monoclonal, Murine-Derived; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000188:drug therapy* / Q000503:physiopathology; D012008:Recurrence; D012044:Regression Analysis; D012074:Remission Induction; D000069283:Rituximab; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D007155:Immunologic Factors; D000069283:Rituximab