title: Experience with low-dose rituximab in off-label indications at two tertiary hospitals.
abstract: BACKGROUND
  Rituximab is a monoclonal antibody directed against B cells and is increasingly used to treat a variety of autoimmune conditions. Most published evidence reporting the successful use of rituximab in off-label indications has empirically used a high-dose regimen (either 375 mg/m(2) weekly for 4 weeks, or 1000 mg × 2), which is the approved course of treatment for lymphoma and rheumatoid arthritis patients.
  
  
  OBJECTIVE
  The aims of this report are to review the indications, outcomes and adverse events of low-dose (500 mg twice, given 1-2 weeks apart), off-label use of rituximab in our institutions, and to review the available evidence.
  
  
  METHODS
  We performed a retrospective audit of the off-label use of low-dose rituximab at two university teaching, tertiary referral hospitals, from mid-2008 until the end of 2011.
  
  
  RESULTS
  Off-label rituximab was given to 52 patients (53 indications) across a heterogeneous group of autoimmune conditions. Outcomes were known for 46 conditions (affecting 45 patients), and of these, complete responses were observed in 16 (35%) conditions and a further 19 (41%) had a partial response. There was no response to rituximab in 11 (24%) patients. There were eight significant adverse events, mostly related to infectious complications.
  
  
  CONCLUSIONS
  This case series suggests that low-dose courses of rituximab can be used off-label to treat several severe and/or refractory immunological disorders with a reasonable safety profile; however, further trials are required in many off-label indications.
authors.affiliation: Department of Rheumatology, Princess Alexandra Hospital, Brisbane, Queensland, Australia. jackychay@hotmail.com
authors.forename: J
authors.initials: J
authors.lastname: Chay
authors.forename: P
authors.initials: P
authors.lastname: Donovan
authors.forename: L
authors.initials: L
authors.lastname: Cummins
authors.forename: P
authors.initials: P
authors.lastname: Kubler
authors.forename: P
authors.initials: P
authors.lastname: Pillans
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage*; D001327:Autoimmune Diseases / Q000188:drug therapy* / Q000453:epidemiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008485:Medical Audit / Q000379:methods / Q000639:trends*; D008875:Middle Aged; D056687:Off-Label Use; D012189:Retrospective Studies; D000069283:Rituximab; D062606:Tertiary Care Centers / Q000639:trends*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D000069283:Rituximab
keywords: autoimmune; off-label use; rituximab