title: No influence of the polymorphisms CYP2C19 and CYP2D6 on the efficacy of cyclophosphamide, thalidomide, and bortezomib in patients with Multiple Myeloma.
abstract: BACKGROUND
  The response to treatment varies among patients with multiple myeloma and markers for prediction of treatment outcome are highly needed. Bioactivation of cyclophosphamide and thalidomide, and biodegradation of bortezomib, is dependent on cytochrome P450 metabolism. We explored the potential influence of different polymorphisms in the CYP enzymes on the outcome of treatment.
  
  
  METHODS
  Data was analyzed from 348 patients undergoing high-dose treatment and stem cell support in Denmark in 1994 to 2004. Clinical information on relapse treatment in 243 individual patients was collected. The patients were genotyped for the non-functional alleles CYP2C19*2 and CYP2D6*3, *4, *5 (gene deletion), *6, and CYP2D6 gene duplication.
  
  
  RESULTS
  In patients who were treated with bortezomib and were carriers of one or two defective CYP2D6 alleles there was a trend towards a better time-to-next treatment. We found no association between the number of functional CYP2C19 and CYP2D6 alleles and outcome of treatment with cyclophosphamide or thalidomide. Neither was the number of functional CYP2C19 and CYP2D6 alleles associated with neurological adverse reactions to thalidomide and bortezomib.
  
  
  CONCLUSIONS
  There was no association between functional CYP2C19 and CYP2D6 alleles and treatment outcome in multiple myeloma patients treated with cyclophosphamide, thalidomide or bortezomib. A larger number of patients treated with bortezomib are needed to determine the role of CYP2D6 alleles in treatment outcome.
authors.affiliation: Dept of Oncology and Haematology, Roskilde Hospital, Copenhagen University, DK-4000 Roskilde, Denmark. avag@regionsjaelland.dk
authors.forename: Annette J
authors.initials: AJ
authors.lastname: Vangsted
authors.forename: Karen
authors.initials: K
authors.lastname: Søeby
authors.forename: Tobias W
authors.initials: TW
authors.lastname: Klausen
authors.forename: Niels
authors.initials: N
authors.lastname: Abildgaard
authors.forename: Niels F
authors.initials: NF
authors.lastname: Andersen
authors.forename: Peter
authors.initials: P
authors.lastname: Gimsing
authors.forename: Henrik
authors.initials: H
authors.lastname: Gregersen
authors.forename: Ulla
authors.initials: U
authors.lastname: Vogel
authors.forename: Thomas
authors.initials: T
authors.lastname: Werge
authors.forename: Henrik B
authors.initials: HB
authors.lastname: Rasmussen
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D001897:Boronic Acids / Q000008:administration & dosage; D000069286:Bortezomib; D003520:Cyclophosphamide / Q000008:administration & dosage; D065731:Cytochrome P-450 CYP2C19; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics; D010641:Phenotype; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011379:Prognosis; D011719:Pyrazines / Q000008:administration & dosage; D012189:Retrospective Studies; D015996:Survival Rate; D013792:Thalidomide / Q000008:administration & dosage
chemical_list: D001897:Boronic Acids; D004273:DNA, Neoplasm; D011719:Pyrazines; D013792:Thalidomide; D000069286:Bortezomib; D003520:Cyclophosphamide; D001189:Aryl Hydrocarbon Hydroxylases; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19; D019389:Cytochrome P-450 CYP2D6