Influence of Late Treatment on How Chronic Myeloid Leukemia Responds to Imatinib

Abstract

INTRODUCTIONIn Brazil, patients with chronic myeloid leukemia (CML) in the chronic phase were not given first-line imatinib treatment until 2008. Therefore, there was a long period of time between diagnosis and the initiation of imatinib therapy for many patients. This study aims to compare the major molecular remission (MMR) rates of early versus late imatinib therapy in chronic phase CML patients.METHODSBetween May 2002 and November 2007, 44 patients with chronic phase CML were treated with second-line imatinib therapy at the Hematology Unit of the Ophir Loyola Hospital (Belém, Pará, Brazil). BCR-ABL transcript levels were measured at approximately six-month intervals using quantitative polymerase chain reaction.RESULTSThe early treatment group presented a 60% probability of achieving MMR, while the probability for those patients who received late treatment was 40%. The probability of either not achieving MMR within one year of the initiation of imatinib therapy or losing MMR was higher in patients who received late treatment (79%), compared with patients who received early treatment (21%, odds ratio=5.75, P=0.012). The probability of maintaining MMR at 30 months of treatment was 80% in the early treatment group and 44% in the late treatment group (P=0.0005).CONCLUSIONSFor CML patients in the chronic phase who were treated with second-line imatinib therapy, the probability of achieving and maintaining MMR was higher in patients who received early treatment compared with those patients for whom the time interval between diagnosis and initiation of imatinib therapy was longer than one year.

Prospects for achieving treatment‐free remission in chronic myeloid leukaemia

“…However, increasing numbers and the molecular complexity of these subclones are correlated with rate and depth of response to TKI therapy which is, in turn, associated with the probability of achieving and maintaining a DMR. This vision is also supported by the observations that a delay in starting the TKI therapy after diagnosis, allowing for a longer interval that can favour the natural tendency of the Ph+ clone to evolve and to generate resistant subclones, is associated with a lower probability of response (Scerni et al , ); a higher degree of subclonal complexity has been found to correlate with the risk of the disease (Branford et al , ).…”

Molecular response to imatinib mesylate of Brazilian patients with chronic myeloid leukemia

“… 18 Scerni et al found that the probability of achieving MMR was significantly higher (60%) in Brazilian patients who received IM within one year of diagnosis than in those who started treatment more than one year after diagnosis (40%). 19 …”

Improving the outcomes of elderly patients with acute myeloid leukemia in a Brazilian University Hospital

“… 13 This delay is particularly experienced by patients waiting to access the limited number of specialized hematology centers. The optimal management of AML and other hematological malignancies 14 necessitates a prompt diagnosis and the initiation of treatment without delay.…”