Hematopoietic progenitor cell mobilization for autologous transplantation - a literature review

ABSTRACT The use of high-dose chemotherapy with autologous support of hematopoietic progenitor cells is an effective strategy to treat various hematologic neoplasms, such as non-Hodgkin lymphomas and multiple myeloma. Mobilized peripheral blood progenitor cells are the main source of support for autologous transplants, and collection of an adequate number of hematopoietic progenitor cells is a critical step in the autologous transplant procedure. Traditional strategies, based on the use of growth factors with or without chemotherapy, have limitations even when remobilizations are performed. Granulocyte colony-stimulating factor is the most widely used agent for progenitor cell mobilization. The association of plerixafor, a C-X-C Chemokine receptor type 4 (CXCR4) inhibitor, to granulocyte colony stimulating factor generates rapid mobilization of hematopoietic progenitor cells. A literature review was performed of randomized studies comparing different mobilization schemes in the treatment of multiple myeloma and lymphomas to analyze their limitations and effectiveness in hematopoietic progenitor cell mobilization for autologous transplant. This analysis showed that the addition of plerixafor to granulocyte colony stimulating factor is well tolerated and results in a greater proportion of patients with non-Hodgkin lymphomas or multiple myeloma reaching optimal CD34+ cell collections with a smaller number of apheresis compared the use of granulocyte colony stimulating factor alone.

Allogeneic bone marrow transplantation for severe aplastic anemia patients with risk factors for poor prognosis: is fludarabine a requirement? / Transplante alogênico de medula óssea em portadores de anemia aplásica severa com fatores de mau prognóstico: é necessário fludarabina?

Hematopoietic progenitor cell transplantation from HLA-identical sibling donors cures 70-90 percent of Severe Aplastic Anemia (sAA) patients. Older age, heavy exposure to transfusions, immunosuppression treatment (IST) with a long interval from diagnosis to transplant and infection at procedure are associated with poor outcomes. We transplanted 18 patients with sAA and at least one risk factor (RF) for poor prognosis (age >35 years, >50 transfusions prior to transplant, unresponsiveness to previous IST and bacterial or fungal infection at transplant) from 2001 to 2005, using cyclophosphamide (CY - 5 patients) or busulfan plus CY (13 patients). Sixteen patients engrafted, two died with no engraftment, three patients had evidence of graft failure at days +67, +524 and +638 (two died and one was rescued with IST). Grade III/IV mucositis occurred in 39 percent but neither aGVHD nor cGVHD were observed. The Kaplan-Meier probability of survival was 75 percent at 2.14 years, with a trend favoring survival by number of RF (1 versus =2 RF) (P = 0.06). These results are comparable to recent data reported with fludarabine-based conditioning in patients with poor prognosis sAA. Due to the small sample size, prospective clinical trials with larger cohorts of patients are needed to confirm the real benefits of fludarabine-based conditioning, and also to define the best agent(s) to be associated with Fludarabine as preparative regimen for sAA patients with poor prognosis.

Transplante de medula óssea de doador irmão HLA-idêntico pode curar 70 por cento-90 por cento dos portadores de anemia aplásica severa (AAs). Pacientes mais idosos, muito transfundidos, longamente tratados com imunossupressão (IS) e com infecções ao tempo do transplante têm pior evolução. Nós transplantamos 18 pacientes com AAs e pelo menos um dos fatores associados a pior prognóstico (idade >35 anos, >50 transfusões antes do transplante, falta de resposta à imunossupressão prévia e infecção bacteriana ou fúngica ao transplante) de 2001 a 2005, com ciclofosfamida (Cy - 5 pacientes) ou bussulfan mais Cy (13 pacientes). Dezesseis pacientes apresentaram pega do enxerto, dois morreram sem pega, três tiveram rejeição aos dias +67, +524 e +638 (dois morreram e um foi resgatado com IS). Mucosite grau III/IV ocorreu em 39 por cento e não observamos DECH aguda ou crônica. A probabilidade de sobrevida pelo método de Kaplan-Meier foi de 75 por cento aos 2,14 anos, e uma tendência a melhor sobrevida foi encontrada entre os portadores de apenas um fator de risco ao transplante (P: .06). Estes resultados são comparáveis a recentes relatos de literatura envolvendo condicionamentos baseados em fludarabina para tratar pacientes com alto risco. Devido à pequena amostra analisada, estudos clínicos prospectivos com maior número de pacientes são necessários, visando comprovar o real benefício dos condicionamentos baseados em fludarabina, definir o melhor agente a ser a ela associado e assim obter o melhor condicionamento para portadores de AAs com fatores de mau prognóstico para o transplante.

O tratamento da Leucemia Mielóide Crônica com mesilato de imatinibe / Therapy of Chronic Myeloid Leukemia with imatinib mesylate

O mesilato de imatinibe é atualmente o tratamento de escolha para pacientes com Leucemia mielóide Crônica (LMC) recém-diagnosticados. Desde os primeiros estudos clínicos em 1998 até o estudo IRIS, que comparou o uso em primeira linha de imatinibe com interferon + ara-C, esta droga vem se consolidando em segurança e eficácia. Ainda há, entretanto questionamentos sobre a melhor dose inicial, a identificação dos pacientes que mais se beneficiariam e a melhor abordagem frente a respostas sub-ótimas e resistência. Os principais estudos clínicos publicados com mesilato de imatinibe são revisados no presente artigo, e discutidos sob a perspectiva da realidade brasileira.

Imatinib mesylate is currently the gold-standard therapy for patients with newly diagnosed Chronic Myelogenous Leukemia. From the clinical trials in 1998 to the IRIS study, which compared first line imatinib treatment with interferon and low dose ara-C, this drug has been consolidated in regards to its safety and efficacy. There are still some questions to answer. Which would be the best initial dose? Are there any patients who benefit more than others? What is the best approach to suboptimal response and resistance? The most important published clinical studies are reviewed in the current article and discussed from a Brazilian perspective.

Therapy of chronic myeloid leukemia with imatinib mesylate in Brazil: a study of 98 cases / Tratamento da leucemia mielóide crônica com imatinib mesilato no Brasil: estudo de 98 casos

Chronic Myeloid Leukemia (CML) is a clonal disease characterized by balanced translocation between chromosomes 9 and 22 (Philadelphia chromosome). The resulting BCR-ABL gene has tyrosine kinase activity which stimulates cellular growth. Imatinib mesylate is a potent and specific inhibitor of all ABL related kinases. Ninety-eight CML patients were treated with imatinib mesylate from October 2000 to January 2003. Disease stage was: late chronic phase resistant or intolerant to alpha-interferon (CP): 28; accelerated phase (AP): 55; blastic phase (BP): 15 patients. Dose: 400 mg for CP and 600 mg for AP or CB. The objectives were to evaluation the efficacy, safety and survival with imatinib mesylate therapy in all phases of CML. The median follow up time was 545 days (range: 7-862), complete hematologic response was 86 percent in CP, 47 percent in AP and 13 percent in BP. Complete cytogenetic response was 61 percent, 24 percent and 0 percent respectively. BCR-ABL was not detected by nested RT-PCR in 9 percent of patients. Grade 3-4 hematologic toxicity was seen in 21 percent of CP, 74 percent of AP and 87 percent of BP patients. Grade 3-4 non-hematologic toxicity was observed in 11 percent of CP, 51 percent of AP and 53 percent of BP patients. Two-year overall survival was 64 percent for all patients, 96 percent for CP and 36 percent for AP patients. All BP patients died within a median of 60 days. Imatinib mesylate induced cytogenetic responses in Brazilian patients with previously treated CML in chronic and accelerated phase. Adverse events are similar to those reported in the literature, except for lower rates of gastrointestinal symptoms and muscle cramps in our study group.

INTRODUÇÃO: A Leucemia Mielóide Crônica (LMC) é uma doença clonal caracterizada pela presença da translocação entre os cromossomos 9 e 22 (cromossomo Philadelphia). O gene resultante BCR-ABL possui atividade de tirosino-quinase, que estimula o crescimento celular. O mesilato de imatinibe é um inibidor potente e específico de todas as quinases relacionadas ao ABL. PACIENTES E MÉTODOS: Noventa e oito pacientes com LMC foram tratados com mesilato de imatinibe de outubro de 2000 a janeiro de 2003: 28 em fase crônica (FC) resistente ou intolerante ao interferon alfa; 55 em fase acelerada (FA) e 55 em crise blástica (CB). Dose: 400 mg para CP e 600 mg para FA ou CB. OBJETIVOS: Avaliação da eficácia, segurança e sobrevida após tratamento da LMC com mesilato de imatinibe. RESULTADOS: Seguimento mediano: 545 dias (variação: 7-862). Resposta hematológica completa ocorreu em 86 por cento dos pacientes em FC, 47 por cento na FA e 13 por cento na CB. Sessenta e um por cento, 24 por cento e 0 por cento dos pacientes em FC, FA e CB, atingiram resposta citogenética completa, respectivamente. Não foram detectados transcritos BCR-ABL por "nested RT-PCR" em 9 por cento dos pacientes. Toxicidade hematológica grau 3-4: 21 por cento na FC, 74 por cento na FA e em 87 por cento na CB. Toxicidade não hematológica grau 3-4: 11 por cento na FC, 51 por cento na FA e 53 por cento na CB. A sobrevida global em dois anos foi de 64 por cento para todos os pacientes, 96 por cento na FC e 36 por cento na FA. Todos os pacientes em CB faleceram numa mediana de 60 dias. CONCLUSÕES: O mesilato de imatinibe induziu respostas citogenéticas completas em pacientes brasileiros com LMC em fase crônica e acelerada. Os eventos adversos nos nossos pacientes foram semelhantes aos relatados em literatura, exceto pela menor incidência de sintomas gastro-intestinais e câimbras.