RESUMO
Imatinib is effective for the treatment of chronic myeloid leukemia (CML). However even undetectable BCR-ABL1 by Q-RT-PCR does not equate to eradication of the disease. Digital-PCR (dPCR), able to detect 1 BCR-ABL1 positive cell out of 10(7) , has been recently developed. The ISAV study is a multicentre trial aimed at validating dPCR to predict relapses after imatinib discontinuation in CML patients with undetectable Q-RT-PCR. CML patients under imatinib therapy since more than 2 years and with undetectable PCR for at least 18 months were eligible. Patients were monitored by standard Q-RT-PCR for 36 months. Patients losing molecular remission (two consecutive positive Q-RT-PCR with at least 1 BCR-ABL1/ABL1 value above 0.1%) resumed imatinib. The study enrolled 112 patients, with a median follow-up of 21.6 months. Fifty-two of the 108 evaluable patients (48.1%), relapsed; 73.1% relapsed in the first 9 months but 14 late relapses were observed between 10 and 22 months. Among the 56 not-relapsed patients, 40 (37.0% of total) regained Q-RT-PCR positivity but never lost MMR. dPCR results showed a significant negative predictive value ratio of 1.115 [95% CI: 1.013-1.227]. An inverse relationship between patients age and risk of relapse was evident: 95% of patients <45 years relapsed versus 42% in the class ≥45 to <65 years and 33% of patients ≥65 years [P(χ(2) ) < 0.0001]. Relapse rates ranged between 100% (<45 years, dPCR+) and 36% (>45 years, dPCR-). Imatinib can be safely discontinued in the setting of continued PCR negativity; age and dPCR results can predict relapse.
Assuntos
Proteínas de Fusão bcr-abl/metabolismo , Mesilato de Imatinib/administração & dosagem , Leucemia Mielogênica Crônica BCR-ABL Positiva , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Adulto , Fatores Etários , Idoso , Feminino , Seguimentos , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/epidemiologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , RecidivaRESUMO
A better understanding of events triggering chronic myeloid leukemia progression is critical for optimized clinical management of chronic myeloid leukemia (CML). We sought to validate that increased expression of Musashi 2 (MSI2), a post-transcription regulator, is associated with progression and prognosis. Screening of 152 patients with CML showed that MSI2 was significantly decreased among patients with CML in chronic phase (CP) at diagnosis (p < 0.0001), but found no significant difference between the normal control group and treated patients with CML in CP. Moreover MSI2 was significantly increased (p < 0.0001) in patients with advance disease (AD) CML. Furthermore, our human hematopoietic cell line data imply that MSI2 and BCR-ABL1 mRNA expression are correlated. However, these data cast a doubt on earlier reports that MSI2 effects HES1 expression via NUMB-NOTCH signaling.
Assuntos
Regulação Leucêmica da Expressão Gênica , Células-Tronco Hematopoéticas/metabolismo , Leucemia Mieloide de Fase Crônica/metabolismo , Leucemia Mieloide de Fase Crônica/patologia , Proteínas de Ligação a RNA/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Progressão da Doença , Feminino , Seguimentos , Proteínas de Fusão bcr-abl/genética , Células-Tronco Hematopoéticas/patologia , Humanos , Técnicas Imunoenzimáticas , Leucemia Mieloide de Fase Crônica/genética , Leucemia Mieloide de Fase Crônica/mortalidade , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Taxa de Sobrevida , Regulação para Cima , Adulto JovemRESUMO
INTRODUCTION: Chronic myeloid leukemia (CML) is a hematopoietic stem cell disease. It is characterized by a Bcr-Abl (breakpoint cluster region-Abelson leukemia virus) tyrosine kinase fusion protein produced from the Philadelphia (Ph) chromosome. The tyrosine kinase inhibitor (TKI) imatinib was the first targeted therapy licensed for patients with chronic-phase CML. In recent years, many other TKIs have been approved for the treatment of patients with CML. For this reason, the choice of the best strategy treatment has become increasingly complex. AREAS COVERED: Bosutinib , a dual Src/Abl kinase inhibitor, has shown potent activity against CML and it has been approved by the US FDA for the treatment of chronic, accelerated or blast-phase Ph+ CML. This review was conducted to describe the preclinical and clinical activity of bosutinib and the safety and tolerability of the drug in the treatment of CML. Included studies were identified through a search of electronic databases in July 2013 and relevant conference proceedings. EXPERT OPINION: Imatinib continues to represent the treatment of choice for CML. However, some patients develop resistance or intolerance to imatinib or to other second-generation TKIs. Bosutinib shows a good therapeutic activity with a benign safety profile, no cardiovascular toxicity, and offers an important therapeutic addition to the armamentarium that physicians can use against resistant CML.