title: Imatinib for melanomas harboring mutationally activated or amplified KIT arising on mucosal, acral, and chronically sun-damaged skin.
abstract: OBJECTIVE
  Amplifications and mutations in the KIT proto-oncogene in subsets of melanomas provide therapeutic opportunities.
  
  
  METHODS
  We conducted a multicenter phase II trial of imatinib in metastatic mucosal, acral, or chronically sun-damaged (CSD) melanoma with KIT amplifications and/or mutations. Patients received imatinib 400 mg once per day or 400 mg twice per day if there was no initial response. Dose reductions were permitted for treatment-related toxicities. Additional oncogene mutation screening was performed by mass spectroscopy.
  
  
  RESULTS
  Twenty-five patients were enrolled (24 evaluable). Eight patients (33%) had tumors with KIT mutations, 11 (46%) with KIT amplifications, and five (21%) with both. Median follow-up was 10.6 months (range, 3.7 to 27.1 months). Best overall response rate (BORR) was 29% (21% excluding nonconfirmed responses) with a two-stage 95% CI of 13% to 51%. BORR was significantly greater than the hypothesized null of 5% and statistically significantly different by mutation status (7 of 13 or 54% KIT mutated v 0% KIT amplified only). There were no statistical differences in rates of progression or survival by mutation status or by melanoma site. The overall disease control rate was 50% but varied significantly by KIT mutation status (77% mutated v 18% amplified). Four patients harbored pretreatment NRAS mutations, and one patient acquired increased KIT amplification after treatment.
  
  
  CONCLUSIONS
  Melanomas that arise on mucosal, acral, or CSD skin should be assessed for KIT mutations. Imatinib can be effective when tumors harbor KIT mutations, but not if KIT is amplified only. NRAS mutations and KIT copy number gain may be mechanisms of therapeutic resistance to imatinib.
authors.affiliation: F. Stephen Hodi, Anita Giobbie-Hurder, Philip Friedlander, Jason J. Luke, Katherine A. Zukotynski, Jeffrey T. Yap, Annick D. Van den Abbeele, and George D. Demetri, Dana-Farber Cancer Institute; Jonathan A. Fletcher, Meijun Zhu, and Adrian Marino-Enriquez, Brigham and Women's Hospital; Donald Lawrence, Keith T. Flaherty, and David E. Fisher, Massachusetts General Hospital, Boston, MA; Christopher L. Corless, Michael C. Heinrich, and Carol Beadling, Portland Veterans Administration Medical Center and Oregon Health & Science University, Portland, OR; Philip Friedlander, Mount Sinai Medical Center, New York, NY; Rene Gonzalez, University of Colorado Cancer Center, Aurora, CO; Jeffrey S. Weber, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL; Thomas F. Gajewski, University of Chicago, Chicago, IL; Steven J. O'Day, Beverly Hills Cancer Center, Beverly Hills, CA; Kevin B. Kim, The University of Texas MD Anderson Cancer Center, Houston, TX; Frances A. Collichio, The University of North Carolina at Chapel Hill, Chapel Hill, NC; and Marc S. Ernstoff, Geisel School of Medicine and Norris Cotton Cancer Center, Hanover, NH.
authors.forename: F Stephen
authors.initials: FS
authors.lastname: Hodi
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Corless
authors.forename: Anita
authors.initials: A
authors.lastname: Giobbie-Hurder
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Fletcher
authors.forename: Meijun
authors.initials: M
authors.lastname: Zhu
authors.forename: Adrian
authors.initials: A
authors.lastname: Marino-Enriquez
authors.forename: Philip
authors.initials: P
authors.lastname: Friedlander
authors.forename: Rene
authors.initials: R
authors.lastname: Gonzalez
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Weber
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Gajewski
authors.forename: Steven J
authors.initials: SJ
authors.lastname: O'Day
authors.forename: Kevin B
authors.initials: KB
authors.lastname: Kim
authors.forename: Donald
authors.initials: D
authors.lastname: Lawrence
authors.forename: Keith T
authors.initials: KT
authors.lastname: Flaherty
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Luke
authors.forename: Frances A
authors.initials: FA
authors.lastname: Collichio
authors.forename: Marc S
authors.initials: MS
authors.lastname: Ernstoff
authors.forename: Michael C
authors.initials: MC
authors.lastname: Heinrich
authors.forename: Carol
authors.initials: C
authors.lastname: Beadling
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Zukotynski
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: Yap
authors.forename: Annick D
authors.initials: AD
authors.lastname: Van den Abbeele
authors.forename: George D
authors.initials: GD
authors.lastname: Demetri
authors.forename: David E
authors.initials: DE
authors.lastname: Fisher
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001549:Benzamides / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000235:genetics; D002908:Chronic Disease; D005260:Female; D020558:GTP Phosphohydrolases / Q000235:genetics; D005784:Gene Amplification; D006801:Humans; D000068877:Imatinib Mesylate; D008297:Male; D008545:Melanoma / Q000188:drug therapy* / Q000235:genetics / Q000401:mortality / Q000473:pathology; D008565:Membrane Proteins / Q000235:genetics; D008875:Middle Aged; D009092:Mucous Membrane / Q000187:drug effects / Q000473:pathology*; D009154:Mutation / Q000235:genetics*; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000235:genetics / Q000401:mortality / Q000473:pathology; D010879:Piperazines / Q000627:therapeutic use*; D011379:Prognosis; D000090063:Proto-Oncogene Mas; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics*; D011743:Pyrimidines / Q000627:therapeutic use*; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000401:mortality / Q000556:secondary; D013472:Sunlight; D015996:Survival Rate
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D014408:Biomarkers, Tumor; C000715470:MAS1 protein, human; D008565:Membrane Proteins; D010879:Piperazines; D000090063:Proto-Oncogene Mas; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D019009:Proto-Oncogene Proteins c-kit; D020558:GTP Phosphohydrolases; C579846:NRAS protein, human