title: Treatment Efficacy and Resistance Mechanisms Using the Second-Generation ALK Inhibitor AP26113 in Human NPM-ALK-Positive Anaplastic Large Cell Lymphoma.
abstract: ALK is a tyrosine kinase receptor involved in a broad range of solid and hematologic tumors. Among 70% to 80% of ALK(+) anaplastic large cell lymphomas (ALCL) are caused by the aberrant oncogenic fusion protein NPM-ALK. Crizotinib was the first clinically relevant ALK inhibitor, now approved for the treatment of late-stage and metastatic cases of lung cancer. However, patients frequently develop drug resistance to Crizotinib, mainly due to the appearance of point mutations located in the ALK kinase domain. Fortunately, other inhibitors are available and in clinical trial, suggesting the potential for second-line therapies to overcome Crizotinib resistance. This study focuses on the ongoing phase I/II trial small-molecule tyrosine kinase inhibitor (TKI) AP26113, by Ariad Pharmaceuticals, which targets both ALK and EGFR. Two NPM-ALK(+) human cell lines, KARPAS-299 and SUP-M2, were grown in the presence of increasing concentrations of AP26113, and eight lines were selected that demonstrated resistance. All lines show IC50 values higher (130 to 1,000-fold) than the parental line. Mechanistically, KARPAS-299 populations resistant to AP26113 show NPM-ALK overexpression, whereas SUP-M2-resistant cells harbor several point mutations spanning the entire ALK kinase domain. In particular, amino acid substitutions: L1196M, S1206C, the double F1174V+L1198F and L1122V+L1196M mutations were identified. The knowledge of the possible appearance of new clinically relevant mechanisms of drug resistance is a useful tool for the management of new TKI-resistant cases.
  
  
  CONCLUSIONS
  This work defines reliable ALCL model systems of AP26113 resistance and provides a valuable tool in the management of all cases of relapse upon NPM-ALK-targeted therapy.
authors.affiliation: Department of Health Science, University of Milano-Bicocca, Monza, Italy. mceccon.manuscript@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Ceccon
authors.affiliation: Department of Health Science, University of Milano-Bicocca, Monza, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Mologni
authors.affiliation: Tettamanti Research Centre, Pediatric Clinic, University of Milano-Bicocca, Monza, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Giudici
authors.affiliation: Department of Health Science, University of Milano-Bicocca, Monza, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Piazza
authors.affiliation: Department of Health Science, University of Milano-Bicocca, Monza, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Pirola
authors.affiliation: Department of Health Science, University of Milano-Bicocca, Monza, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Fontana
authors.affiliation: Department of Health Science, University of Milano-Bicocca, Monza, Italy. Section of Haematology, San Gerardo Hospital, Monza, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Gambacorti-Passerini
mesh_terms: D019943:Amino Acid Substitution; D000077548:Anaplastic Lymphoma Kinase; D045744:Cell Line, Tumor; D019008:Drug Resistance, Neoplasm; D059472:Exome; D006801:Humans; D020128:Inhibitory Concentration 50; D017728:Lymphoma, Large-Cell, Anaplastic / Q000188:drug therapy / Q000235:genetics*; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D017354:Point Mutation; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D011743:Pyrimidines / Q000494:pharmacology*; D020794:Receptor Protein-Tyrosine Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D015854:Up-Regulation
chemical_list: D009943:Organophosphorus Compounds; D011743:Pyrimidines; C107023:p80(NPM-ALK) protein; C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases; C000598580:brigatinib