Identification and validation of phospho-SRC, a novel and potential pharmacodynamic biomarker for dasatinib (SPRYCEL), a multi-targeted kinase inhibitor

Cancer Chemother Pharmacol. 2008 Nov;62(6):1065-74. doi: 10.1007/s00280-008-0699-5. Epub 2008 Feb 27.

Abstract

Purpose: Dasatinib (BMS-354825) is a potent, oral multi-targeted kinase inhibitor. It is an effective therapy for patients with imatinib-resistant or -intolerant Ph+ leukemias,. It has demonstrated promising preclinical anti-tumor activity, and is under clinical evaluation in solid tumors. To support the clinical development of dasatinib, we identified a pharmacodynamic biomarker to assess in vivo SRC kinase inhibition, with subsequent evaluation in cancer patients.

Methods: The biomarker, phosphorylated SRC (phospho-SRC), was first identified in human prostate PC-3 tumor cells and peripheral blood mononuclear cells (PBMCs) in vitro. It was further assessed in nude mice bearing PC-3 xenografts. Phospho-SRC[pY418] in tumors and PBMC were measured by western blot analysis, and were quantified by ELISA assays. Dasatinib plasma concentrations were determined using LC/MS/MS.

Results: In PC-3 cells, dasatinib showed dose-dependent anti-proliferative effect, which correlated with the inhibition of phospho-SRC[pY418] and of SRC kinase activity. With a single oral dose of 50 or 15 mg/kg, tumoral phospho-SRC[pY418] was maximally inhibited at 3 h, partially reversed between 7 and 17 h, and completely recovered after 24 h post dose. At 5 mg/kg, tumoral phospho-SRC[pY418] inhibition was less pronounced and recovered more rapidly to baseline level within 24h. Dasatinib (1 mg/kg) resulted in little inhibition. In PBMCs, a similar time course and extent of phospho-SRC[pY418] inhibition was observed. Inhibition of phospho-SRC[pY418] in vivo appeared to correlate with the preclinical in vivo efficacy and PK profiles of dasatinib in mice.

Conclusions: Phospho-SRC[pY418] may potentially be used as a biomarker to enable assessment of target inhibition in clinical studies exploring dasatinib antitumor activity.

Publication types

  • Validation Study

MeSH terms

  • Adenocarcinoma / chemistry
  • Adenocarcinoma / drug therapy
  • Adenocarcinoma / pathology*
  • Animals
  • Antineoplastic Agents / administration & dosage
  • Antineoplastic Agents / pharmacokinetics
  • Antineoplastic Agents / pharmacology*
  • Antineoplastic Agents / therapeutic use
  • Biomarkers
  • Cell Division / drug effects
  • Dasatinib
  • Drug Monitoring / methods*
  • Female
  • Humans
  • Leukocytes, Mononuclear / chemistry
  • Leukocytes, Mononuclear / drug effects
  • Male
  • Mice
  • Mice, Nude
  • Neoplasm Proteins / analysis
  • Neoplasm Proteins / antagonists & inhibitors*
  • Neoplasm Proteins / blood
  • Phosphoproteins / antagonists & inhibitors
  • Phosphorylation
  • Prostatic Neoplasms / chemistry
  • Prostatic Neoplasms / drug therapy
  • Prostatic Neoplasms / pathology*
  • Protein Kinase Inhibitors / administration & dosage
  • Protein Kinase Inhibitors / pharmacokinetics
  • Protein Kinase Inhibitors / pharmacology*
  • Protein Kinase Inhibitors / therapeutic use
  • Pyrimidines / administration & dosage
  • Pyrimidines / pharmacokinetics
  • Pyrimidines / pharmacology*
  • Pyrimidines / therapeutic use
  • Specific Pathogen-Free Organisms
  • Substrate Specificity
  • Thiazoles / administration & dosage
  • Thiazoles / pharmacokinetics
  • Thiazoles / pharmacology*
  • Thiazoles / therapeutic use
  • Xenograft Model Antitumor Assays
  • src-Family Kinases / analysis*
  • src-Family Kinases / antagonists & inhibitors
  • src-Family Kinases / blood

Substances

  • Antineoplastic Agents
  • Biomarkers
  • Neoplasm Proteins
  • Phosphoproteins
  • Protein Kinase Inhibitors
  • Pyrimidines
  • Thiazoles
  • src-Family Kinases
  • Dasatinib