title: Association between regular molecular monitoring and tyrosine kinase inhibitor therapy adherence in chronic myelogenous leukemia in the chronic phase.
abstract: OBJECTIVE
  Adherence with oral tyrosine kinase inhibitor (TKI) therapy over prolonged timeframes is required for successful outcomes among patients with chronic phase chronic myelogenous leukemia (CP-CML). Since quantitative polymerase chain reaction (qPCR) monitoring may identify early suboptimal responses, and thereby permit detection of non-adherence to therapy, we sought to assess the association between frequency of molecular monitoring and medication adherence.
  
  
  METHODS
  This is a retrospective cohort study design of diagnosed CP-CML obtained from two large US administrative claims databases. Patients were grouped into cohorts based on the number of qPCR tests they had. Adherence was assessed both by medication possession ratio (MPR) and proportion of days covered (PDC) and was compared between qPCR cohorts. A sensitivity analysis was performed by adjusting for the number of oncology outpatient visits not due to routine molecular monitoring.
  
  
  RESULTS
  Over the 12 month study period, 1205 CML patients met the selection criteria; 41.0% had no qPCR tests, 31.9% had 1-2 tests, and 27.1% had 3-4 tests; 88.9% of patients were initiated on imatinib. Patients in the 3-4 qPCR tests cohort had an average MPR that was 10.22 (p < 0.001) and 9.54 (p < 0.001) percentage points higher compared to patients in the 0 tests cohort and the 1-2 tests cohort. When using PDC as a measure of adherence, similar results were obtained. The results of the sensitivity analysis were consistent with core analysis findings, excluding number of physician visits as a potential driver of adherence.
  
  
  CONCLUSIONS
  These findings demonstrate an association, not causation, between molecular monitoring frequency and adherence.
  
  
  CONCLUSIONS
  Frequent molecular monitoring (3-4 times per year as recommended in current guidelines) is associated with greater TKI treatment adherence for patients diagnosed with CML. Since TKI adherence >80% has been associated with better clinical outcomes, this study underscores the importance of molecular monitoring.
authors.affiliation: Analysis Group Inc. , Boston, MA , USA.
authors.forename: Annie
authors.initials: A
authors.lastname: Guérin
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.forename: Katherine
authors.initials: K
authors.lastname: Dea
authors.forename: Eric Q
authors.initials: EQ
authors.lastname: Wu
authors.forename: Stuart L
authors.initials: SL
authors.lastname: Goldberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001549:Benzamides / Q000627:therapeutic use*; D002908:Chronic Disease; D015331:Cohort Studies; D016903:Drug Monitoring / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D000068877:Imatinib Mesylate; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000627:therapeutic use*; D016133:Polymerase Chain Reaction / Q000706:statistics & numerical data; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011743:Pyrimidines / Q000627:therapeutic use*; D012189:Retrospective Studies
chemical_list: D001549:Benzamides; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D011505:Protein-Tyrosine Kinases
keywords: Chronic myelogenous leukemia; Medication adherence; Quantitative real time polymerase chain reaction; Tyrosine kinase inhibitor