title: Dose-Dependent Mutation Rates Determine Optimum Erlotinib Dosing Strategies for EGFR Mutant Non-Small Cell Lung Cancer Patients.
abstract: BACKGROUND
  The advent of targeted therapy for cancer treatment has brought about a paradigm shift in the clinical management of human malignancies. Agents such as erlotinib used for EGFR-mutant non-small cell lung cancer or imatinib for chronic myeloid leukemia, for instance, lead to rapid tumor responses. Unfortunately, however, resistance often emerges and renders these agents ineffective after a variable amount of time. The FDA-approved dosing schedules for these drugs were not designed to optimally prevent the emergence of resistance. To this end, we have previously utilized evolutionary mathematical modeling of treatment responses to elucidate the dosing schedules best able to prevent or delay the onset of resistance. Here we expand on our approaches by taking into account dose-dependent mutation rates at which resistant cells emerge. The relationship between the serum drug concentration and the rate at which resistance mutations arise can lead to non-intuitive results about the best dose administration strategies to prevent or delay the emergence of resistance.
  
  
  METHODS
  We used mathematical modeling, available clinical trial data, and different considerations of the relationship between mutation rate and drug concentration to predict the effectiveness of different dosing strategies.
  
  
  RESULTS
  We designed several distinct measures to interrogate the effects of different treatment dosing strategies and found that a low-dose continuous strategy coupled with high-dose pulses leads to the maximal delay until clinically observable resistance. Furthermore, the response to treatment is robust against different assumptions of the mutation rate as a function of drug concentration.
  
  
  CONCLUSIONS
  For new and existing targeted drugs, our methodology can be employed to compare the effectiveness of different dose administration schedules and investigate the influence of changing mutation rates on outcomes.
authors.affiliation: Department of Biostatistics, Harvard T. H. Chan School of Public Health, Boston, MA 02115, United States of America.|Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA 02215, United States of America.
authors.forename: Lin L
authors.initials: LL
authors.lastname: Liu
authors.affiliation: Department of Biostatistics, Harvard T. H. Chan School of Public Health, Boston, MA 02115, United States of America.
authors.forename: Fei
authors.initials: F
authors.lastname: Li
authors.affiliation: Vanderbilt-Ingram Cancer Center, Nashville, TN 27232, United States of America.
authors.forename: William
authors.initials: W
authors.lastname: Pao
authors.affiliation: Department of Biostatistics, Harvard T. H. Chan School of Public Health, Boston, MA 02115, United States of America.|Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, MA 02215, United States of America.
authors.forename: Franziska
authors.initials: F
authors.lastname: Michor
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000235:genetics; D000069347:Erlotinib Hydrochloride / Q000494:pharmacology*; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D008962:Models, Theoretical; D009154:Mutation / Q000235:genetics*; D059645:Mutation Rate; D047428:Protein Kinase Inhibitors / Q000494:pharmacology
chemical_list: D047428:Protein Kinase Inhibitors; D000069347:Erlotinib Hydrochloride; C512478:EGFR protein, human; D066246:ErbB Receptors