title: Clinical evaluation of natalizumab for formulary consideration.
abstract: BACKGROUND
  Natalizumab is a monotherapy for relapsing forms of multiple sclerosis (MS) and maintaining remission in Crohn's disease (CD). Evaluation of natalizumab's clinical relevance must be performed before considering its place in treatment of these diseases.
  
  
  METHODS
  MEDLINE and PubMed searches were performed using the keywords multiple sclerosis, Crohn's disease, natalizumab and clinical trials. The manufacturer's product information was consulted to extract additional data. Pivotal clinical trials included: Natalizumab Safety and Efficacy in Relapsing Remitting Multiple Sclerosis (AFFIRM), Safety and Efficacy of Natalizumab in Combination With Interferon Beta-1a in Patients With Relapsing Remitting Multiple Sclerosis (SENTINEL), Efficacy of Natalizumab as Active Crohn's Therapy (ENACT)-1 and 2 and Efficacy of Natalizumab in Crohn's Disease Response and Remission (ENCORE).
  
  
  RESULTS
  AFFIRM and SENTINEL showed improvements in progression of MS. ENACT-1 failed to show a significant effect, but the follow-up trials ENACT-2 and ENCORE were able to demonstrate a response to natalizumab.
  
  
  CONCLUSIONS
  Two trials on efficacy of Tysabri for treatment of MS demonstrated positive results. Efficacy for CD was mixed. More research demonstrating head-to-head evidence against other agents is necessary to determine if Tysabri's benefits are significant.
authors.affiliation: University of Maryland School of Pharmacy, Center on Drugs and Public Policy, Baltimore, MD 21201, USA.
authors.forename: Ashley
authors.initials: A
authors.lastname: Bivins
authors.forename: Karolyn
authors.initials: K
authors.lastname: Hou
authors.forename: Nana
authors.initials: N
authors.lastname: Ayesu
authors.forename: Brian
authors.initials: B
authors.lastname: Ellsworth
authors.forename: Susan
authors.initials: S
authors.lastname: Montenegro
authors.forename: Xiao
authors.initials: X
authors.lastname: Tu
authors.forename: Cynthia
authors.initials: C
authors.lastname: Boyle
authors.forename: Thomas
authors.initials: T
authors.lastname: Dowling
authors.forename: Fadia T
authors.initials: FT
authors.lastname: Shaya
mesh_terms: D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D002986:Clinical Trials as Topic; D003424:Crohn Disease / Q000188:drug therapy*; D019317:Evidence-Based Medicine; D005569:Formularies as Topic; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy*; D000069442:Natalizumab; D016896:Treatment Outcome
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D007166:Immunosuppressive Agents; D000069442:Natalizumab