title: The early molecular response to imatinib predicts cytogenetic and clinical outcome in chronic myeloid leukaemia.
abstract: Real-time quantitative reverse transcription-polymerase chain reaction (Q-RT-PCR) is increasingly used to monitor responses in chronic myeloid leukaemia (CML). The peripheral blood BCR-ABL/ABL ratio, as assessed by Q-RT-PCR, has been shown to correlate with the contemporary cytogenetic response in patients receiving imatinib (Glivec, Gleevec). We have used Q-RT-PCR to monitor the early molecular response to 4 weeks and 3 months of imatinib therapy, in 47 patients with established CML. After 4 weeks of imatinib therapy, patients whose BCR-ABL/ABL ratio had fallen to less than 50% that of baseline had a significantly higher probability of achieving a major cytogenetic response after 6 months of therapy, when compared with those whose ratio did not fall by this amount (P < 0.001). Similarly, patients whose ratio at 3 months was less than 10% of that at baseline had a significantly higher probability of achieving a major cytogenetic remission at 6 months (P < 0.001). Patients who achieved these falls in their BCR-ABL/ABL ratio at either 4 weeks or 3 months had a superior progression-free survival at a median follow-up of 16.5 months (P = 0.01 and 0.003 respectively). These effects were independent of patient age and disease stage. The occurrence of peripheral blood cytopenias sufficiently severe to interrupt therapy was unrelated to progression-free survival. In conclusion, the data suggest that the early trend in the BCR-ABL/ABL ratio may be clinically useful for the early identification of patients destined to fare poorly on imatinib.
authors.affiliation: Department of Haematology, Royal Liverpool University Hospital, UK.
authors.forename: Lihui
authors.initials: L
authors.lastname: Wang
authors.forename: Kevin
authors.initials: K
authors.lastname: Pearson
authors.forename: Julia E
authors.initials: JE
authors.lastname: Ferguson
authors.forename: Richard E
authors.initials: RE
authors.lastname: Clark
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001549:Benzamides; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D016044:Fusion Proteins, bcr-abl / Q000235:genetics*; D005819:Genetic Markers; D006801:Humans; D000068877:Imatinib Mesylate; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy* / Q000235:genetics / Q000401:mortality; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000627:therapeutic use*; D016315:Proto-Oncogene Proteins c-abl / Q000235:genetics*; D011743:Pyrimidines / Q000627:therapeutic use*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D005819:Genetic Markers; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D016044:Fusion Proteins, bcr-abl; D016315:Proto-Oncogene Proteins c-abl