RESUMO

BACKGROUND: A lower dosage of tyrosine kinase inhibitors (TKIs) in patients with chronic myeloid leukaemia (CML) has shown efficacy in managing short-term toxicity and maintaining a deep molecular response in patients who fail to achieve treatment-free remission. METHOD: From over 700 patients with CML who were treated at two centres over the last three decades, this retrospective study identified eight patients characterised by long-term treatment failure and simultaneous prolonged significant haematologic toxicity that prevented the use of the standard tyrosine kinase inhibitor dosage. RESULTS: Patients had a high or intermediate ELTS risk score, and most had significant comorbidities. Two patients were treated previously with busulfan, and four were aged over 70, which might explain the reduced pool of normal haematopoietic stem cells. However, concomitant myelodysplastic syndrome or the presence of clonal haematopoiesis of indeterminate potential was not demonstrated. Despite prolonged treatment failure, the survival of these patients (who were ineligible for stem cell transplantation) ranged from 45-396 months. Neither mutations in the ABL kinase domain nor additional cytogenetic abnormalities developed during the treatment of these patients, prompting speculation about the low selective pressure of low-dose tyrosine kinase inhibitors and/or the absence of mutations at diagnosis. CONCLUSION: It is important not to stop treatment with tyrosine kinase inhibitors at a low personalised dosage in CML patients with prolonged significant haematologic toxicity despite long-term treatment failure.

RESUMO

In the tyrosine kinase inhibitor era, the blast phase of chronic myeloid leukaemia (BP-CML) renders an uncommon presentation and has a poor prognosis with an estimated overall survival below 20%. Mixed-phenotype blast phase is even more infrequent, presenting in 3.3% of these patients. Blast phase manifests along haematological sarcomas, with extramedullary activity in lymph nodes, skin and bone. We report the case of a patient with an ovarian sarcoma as an extramedullary presentation of mixed-phenotype BP-CML refractory to conventional treatment which responded to immunotherapy against CD33 and CD19.

Assuntos

Assuntos

RESUMO

AIMS: Despite their overall favourable safety profile, tyrosine kinase inhibitors (TKIs) are related to severe adverse events including haematological toxicities such as anaemia, leucopenia, neutropenia and thrombocytopenia. We designed a systematic review and network meta-analysis of randomised controlled trials to compare safety among TKIs (bosutinib, dasatinib, imatinib, nilotinib, ponatinib and radotinib) used by patients diagnosed with chronic myeloid leukaemia. METHODS: We obtained data from the PubMed, Scopus, Web of Science, and SciELO databases. The Bayesian approach was used for direct and indirect comparisons, and the treatments were ranked by the surface under the cumulative ranking curve (SUCRA). RESULTS: Seventeen studies were included in the network meta-analysis. Our data show that dasatinib was generally considered worse than the other TKIs, with SUCRA values ​​for 140 mg dasatinib of 90.3% for anaemia, 87.4% for leucopenia, 90.6% for neutropenia and 97.2% for thrombocytopenia. In addition, nilotinib was shown to be safer, with SUCRA values ​​for 600 and 800 mg doses of 21.9 and 35.8% for anaemia, 23.8 and 14.6% for leucopenia, 33.0 and 17.7% for neutropenia, and 28.7 and 32.6% for thrombocytopenia, respectively. CONCLUSION: Dasatinib appeared as the least safe drug for chronic myeloid leukaemia, probably because it binds to multiple key kinase targets, being more prone to cause serious haematological adverse events. Nilotinib demonstrated a safer profile, mostly due to its selective binding capacity.

Assuntos

RESUMO

Resumen Se presentan dos casos clínicos de pacientes con leucemia mieloide crónica en fase acelerada, hospitalizados para inicio de terapia dirigida con inhibidores de tirosina cinasa (dasatinib). Posteriormente se determina la presencia de sangrado intraparenquimatoso a sistema nervioso central. Para finalizar, se revisa la literatura disponible a cerca de eventos adversos tipo sangrado asociados a dasatinib y los posibles condicionantes de este desenlace.

Abstract Two clinical cases are presented on patients with chronic myeloid leukaemia in accelerated phase, who were admitted to hospital for initiation of targeted therapy with tyrosine kinase inhibitors (Dasatinib). Intraparenchymal bleeding in the central nervous system was subsequently observed. A review was also made on the available literature on bleeding-related adverse events associated with Dasatinib and the possible determining factors of this outcome.

Assuntos

RESUMO

Resumen Introducción: Las mutaciones en el dominio BCR-ABL1, tirosina quinasa (TK) son mecanismos importantes de resistencia de los inhibidores de la tirosina quinasa (ITK) en pacientes con leucemia mieloide crónica (LMC). Objetivo: Determinar el tipo y la frecuencia de las mutaciones en el dominio tirosina quinasa del gen BCR-ABL1, asociadas con falla en la respuesta al tratamiento con imatinib en pacientes con LMC y correlacionar el perfil de mutaciones con los hallazgos clínicos, demográficos, respuesta citogenética y respuesta molecular. Materiales y métodos: Se realizó un estudio descriptivo de tipo prospectivo en pacientes con LMC en tratamiento con IMATINIB a quienes se les realizó cariotipo y análisis de mutaciones del dominio BCR-ABL1 mediante la técnica de PCR anidada. Resultados: De los 23 pacientes estudiados en cuatro se encontraron mutaciones: dos presentaron la mutación E255K, uno presentó la mutación H396P y otro presentó doble mutación L387L y T389P. Las mutaciones E255K que se ubican en la región P-loop y H396P en A-loop se asocian con mal pronóstico. La mutación T389P localizada en la región A-loop no está informada en algunas bases de datos. Conclusiones: En este estudio encontramos cuatro mutaciones en el dominio tirosina quinasa (E255K, H396P, L387L y T389P) que podrían aportar información valiosa y guiar las decisiones de tratamiento. Es importante destacar que esta investigación de análisis mutacional del dominio BCR-ABL es la primera que se realiza en el país con la particularidad adicional de cubrir una población triétnica.

Abstract Mutations in the BCR-ABL1 tyrosine kinase domain mutations, are one of the principal mechanisms associated with tyrosine kinase inhibitors (TKI) resistance in patients with chronic myeloid leukaemia (CML). Objectives: To determine the type and frequency of mutations in the tyrosine kinase domain of the BCR-ABL1 gene associated with failure to respond to treatment with Imatinib and Imatinib in patients with CMK, and to correlate the mutation profile with the clinical and demographic variables, as well as the cytogenetic and molecular response. Materials and methods: A descriptive prospective study was carried out on patients with CML treated with Imatinib. Karyotyping and analysis of the BCR-ABL1 domain mutations were performed on the patients using nested PCR. Results: Four types of mutations were found in the 23 patients studied, of which two of them were the E225 mutation, one with the H396P mutation, another with a double mutation L387L and T389P. Both the E255K mutation located in the P-loop region, and H396P mutation in the A-loop region, are associated with a poor prognosis. The T389P mutation located within A-loop region has not been reported in any of the databases. Conclusions: Four mutations were found in the tyrosine kinase domain (E255K, H396P, L387L and T389P) were found in this study. These findings provide valuable information and as a guideline to help make treatment decisions. It is important to point out that this analytical study on mutations of the BCR-ABL domain is the first one carried out in the country and, specifically, in a tri-ethnic population.

Assuntos

RESUMO

Nilotinib es un inhibidor altamente selectivo de BCR-ABL tirosina kinasa usado para el tratamiento de Leucemia mieloide crónica. Las reacciones cutáneas fueron uno de los efectos adversos no hematológicos más frecuentemente reportados en relación al uso de esta droga. El presente artículo documenta el caso una paciente femenina de 17 años de edad diagnosticada con Leucemia mieloide crónica que había estado en tratamiento con Nilotinib por 5 meses desarrollando una reacción tipo queratosis pilar. La paciente fue tratada con medidas generales, Urea 15% y antihistamínicos, con cese del prurito. Es importante reconocer las reacciones cutáneas asociadas al uso de Nilotinib para así otorgar alivio oportuno de los síntomas con el fin de lograr una mejor adherencia al tratamiento de la Leucemia mieloide crónica y mejorar la calidad de vida del paciente.

Nilotinib is a highly selective inhibitor of BCR-ABL tyrosine kinase. It is used as a treatment for chronic myelogenous leukemia (CML). Cutaneous reactions are one of the most common non-hematologic reported adverse effects. The present article documents the case of a 17-year-old female patient diagnosed with CML. She was treated with nilotinib for 5 months and developed a keratosis pilaris-like reaction. The patient was treated with general measures, topical 15%-urea and antihistamines with improvement and cessation of pruritus. It is imperative to recognize the cutaneous adverse effects associated with the use of new oncologic treatments such as nilotinib.

Assuntos

RESUMO

OBJECTIVE: Data on the use of Imatinib (IM) in developing countries remain limited. A retrospective study was done to assess the efficacy and toxicity of IM in treating chronic myeloid leukaemia (CML) in Trinidad and Tobago. METHODS: Patients in all phases of CML who started IM therapy between February 2001 and February 2004 were included. All had received other previous therapy. They were assessed for haematological, cytogenetic and molecular response, overall survival (OS), event free survival (EFS) and adverse effects (AE). RESULTS: Twenty-five patients were followed-up for a median 61 months. At initiation ofIM, 18 were in the chronic phase (CP), 3 in accelerated phase (AP), 3 in blast crisis (BC) and one in myelofibrotic transformation (MF). Overall, 96% of patients achieved complete haematological remission (CHR). Among CP patients, 67% attained a major cytogenetic response (MCR) and 44% a complete cyto genetic response (CCR). Overall survival and event free survival in the CP group were 82% and 76% respectively. Overall survival for advanced phase patients was 14% at 61 months The adverse effects of IM were the same as previously described and generally tolerable. No patient opted to discontinue IM because ofside effects. CONCLUSION: After 5 years of follow-up, IM was found to induce favourable and durable survival responses with an acceptable side effect profile in CP-CML patients who had received prior treatment with alternative agents.

OBJETIVO: Los datos sobre el uso de imatinib (IM) en los países en vías de desarrollo, siguen siendo limitados. Se hizo un estudio retrospectivo con el fin de evaluar la eficacia y toxicidad de IM en el tratamiento de la leucemia mieloide crónica (LMC) en Trinidad y Tobago. MÉTODOS: Se incluyeron todos los pacientes -en todas las fases de LMC - que empezaron la terapia de IM entre febrero de 2001 y febrero de 2004. Todos habían recibido otra terapia previamente. Se les evaluó con respecto a su respuesta hematológica, citogenética y molecular, supervivencia global (SG), supervivencia libre de eventos (SLE), y efectos adversos (EA). RESULTADOS: Veinticinco pacientes tuvieron seguimiento por espacio de 61 meses como promedio. En la iniciación de IM, 18 estaban en fase crónica (FC), 3 en la fase acelerada (FA), 3 en crisis blástica (CB) y uno en transformación mielofibrótica (MF). En general, 96% de los pacientes lograron la remisión hematológica completa (RHC). Entre los pacientes de CF, 67% lograron una repuesta citogénica mayor (RCM) y 44% una respuesta citogénica completa (RCC). La supervivencia global (SG) y la supervivencia libre de eventos (SLE) en el grupo FC fueron 82% y 76% respectivamente. La supervivencia global para los pacientes en fase avanzada fue de 14% en 61 meses. Los EA de IM fueron los mismos previamente descritos, y eran generalmente tolerables. Ningún paciente optó por discontinuar IM debido a efectos adversos. CONCLUSIÓN: Después de 5 años de seguimiento, se halló que IM induce respuestas de supervivencia favorables y duraderas en los pacientes de LMC-FC previamente tratados, con un perfil aceptable de efectos colaterales.

Assuntos

RESUMO

The introduction of the BCR-ABL kinase inhibitor, imatinib mesylate (Gleevec®, Novartis) led to significant changes in the treatment of chronic myeloid leukaemia (CML) patients. However, despite the impressive percentage of responding patients, some CML cases, particularly those in advanced phases of the disease, show primary resistance or relapse after the initial response. The second-generation BCR-ABL inhibitors nilotinib (Tasigna®, Novartis) and dasatinib (Sprycel®, Bristol-Myers Squibb) have shown significant activity in clinical trials in patients who failed imatinib therapy, but these agents are still incapable of inhibiting the T315I mutant of Bcr-Abl and present partial activity in advanced phases of CML. The acquired biological notions of the mechanisms of tyrosine kinase inhibitor (TKI) resistance has led to the development of new compounds, some of which have shown encouraging preliminary results in clinical trials, even against T315I mutants. In this paper we discuss the new emerging therapies which may overcome TKI resistance in CML patients.

A introdução do inibidor de tirosino quinase BCR-ABL mesilato de imatinibe (Glivec®, Novartis) levou a significantes mudanças no tratamento da LMC. Entretanto, a despeito de impressionante porcentagem de pacientes que respondem, alguns casos de LMC, particularmente em fases avançadas da doença mostram resistência primaria ou recidivas após terapêutica inicial. Inibidores de tirosino quinases de segunda geração como o nilotinibe (Tasigna®, Novartis) e o dasatinibe (Sprycel®, Bristol Myers Squibb) têm mostrado significante atividade nos estudos clínicos em paciente onde o imatinibe falhou. Porém, estes agentes não são capazes de inibir a mutação T315I do Bcr-Abl e apresentam atividade parcial em fases avançadas da LMC. As noções biológicas adquiridas sobre os mecanismos de resistência aos inibidores de TK levaram ao desenvolvimento de novos compostos alguns dos quais têm resultados preliminares encorajadores incluindo a mutação T315I. Neste trabalho nós discutimos os novos agentes emergentes e qual o potencial poderão atingir para ultrapassar a resistência aos inibidores de TK em pacientes com LMC.

Assuntos