title: Characterization of compound 584, an Abl kinase inhibitor with lasting effects.
abstract: BACKGROUND
  Resistance to imatinib is an important clinical issue in the treatment of Philadelphia chromosome-positive leukemias which is being tackled by the development of new, more potent drugs, such as the dual Src/Abl tyrosine kinase inhibitors dasatinib and bosutinib and the imatinib analog nilotinib. In the current study we describe the design, synthesis and biological properties of an imatinib analog with a chlorine-substituted benzamide, namely compound 584 (cmp-584).
  
  
  METHODS
  To increase the potency, we rationally designed cmp-584, a compound with enhanced shape complementarity with the kinase domain of Abl. cmp-584 was synthesized and characterized in vitro against a panel of 67 serine/threonine and tyrosine kinases using radioactive and enzyme-linked immunosorbent kinase assays. We studied inhibitory cellular activity using Bcr/Abl-positive human cell lines, murine transfectants in proliferation experiments, and a murine xenotrans-planted model. Kinase assays on isolated Bcr/Abl protein were also performed. Finally, we used a wash-out approach on whole cells to study the binding kinetics of the inhibitor.
  
  
  RESULTS
  cmp-584 showed potent anti-Abl activity both on recombinant protein (IC(50): 8 nM) and in cell-based assays (IC(50): 0.1-10 nM). The drug maintained inhibitory activity against platelet-derived growth factor receptors and c-KIT and was also active against Lyn (IC(50): 301 nM). No other kinase of the panel was inhibited at nanomolar doses. cmp-584 was 20- to 300-fold more active than imatinib in cells. This superior activity was evident in intact cells, in which full-length Bcr-Abl is present. In vivo experiments confirmed the activity of cmp-584. Wash-out experiments showed that short exposure to the drug impaired cell proliferation and Bcr-Abl phosphorylation for a substantially longer period of time than imatinib.
  
  
  CONCLUSIONS
  The present results suggest a slower off-rate (dissociation rate) of cmp-584 compared to imatinib as an explanation for the increased cellular activity of the former.
authors: School of Pharmaceutical Sciences, University of Geneva, Quai Ernest-Ansermet 30, 1211 Genève 4, Switzerland.
authors: Miriam
authors: M
authors: Puttini
authors: Sara
authors: S
authors: Redaelli
authors: Loris
authors: L
authors: Moretti
authors: Stefania
authors: S
authors: Brussolo
authors: Rosalind H
authors: RH
authors: Gunby
authors: Luca
authors: L
authors: Mologni
authors: Edoardo
authors: E
authors: Marchesi
authors: Loredana
authors: L
authors: Cleris
authors: Arianna
authors: A
authors: Donella-Deana
authors: Peter
authors: P
authors: Drueckes
authors: Elisa
authors: E
authors: Sala
authors: Vittorio
authors: V
authors: Lucchini
authors: Michael
authors: M
authors: Kubbutat
authors: Franca
authors: F
authors: Formelli
authors: Alfonso
authors: A
authors: Zambon
authors: Leonardo
authors: L
authors: Scapozza
authors: Carlo
authors: C
authors: Gambacorti-Passerini
mesh_terms: D000813:Anilides / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D001549:Benzamides / Q000737:chemistry; D045744:Cell Line, Tumor; D002626:Chemistry, Pharmaceutical / Q000379:methods; D019008:Drug Resistance, Neoplasm; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D000068877:Imatinib Mesylate; D007938:Leukemia / Q000188:drug therapy*; D051379:Mice; D009368:Neoplasm Transplantation; D010879:Piperazines / Q000494:pharmacology; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D017434:Protein Structure, Tertiary; D016315:Proto-Oncogene Proteins c-abl / Q000037:antagonists & inhibitors*; D011743:Pyrimidines / Q000737:chemistry / Q000494:pharmacology*
chemical_list: C531555:3-chloro-4-(4-methylpiperazin-1-ylmethyl)-N-(4-methyl-3-(4-pyridin-3-ylpyrimidin-2-ylamino)phenyl)benzamide; D000813:Anilides; D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D016315:Proto-Oncogene Proteins c-abl