INTRODUCTION Chronic myeloid leukemia is the first malignant disease to be associated with a genetic lesion and is the first leukemia to provide a genotype model conducive to targeted molecular therapy. It is a chronic clonal myeloproliferative disorder, originating in a pluripotent stem cell common to all three hematopoietic lineages, characterized by overproduction of myeloid cells in all stages of maturation.

Approval of the use of imatinib in the United States in 2001 and its introduction in the treatment of chronic myeloid leukemia changed the evolution and prognosis of the disease and began the era of molecular therapy for malignancies. Imatinib is highly effective and causes fewer adverse reactions than earlier treatments based on interferon and hydroxyurea.

In Cuba, chronic myeloid leukemia has been treated with interferon since 1998. Starting in 2003, imatinib was gradually introduced for use in newly-diagnosed chronic myeloid leukemia patients.

OBJECTIVE Evaluate the use of imatinib as first-line therapy for chronic myeloid leukemia in a group of Cuban patients, based on hematologic, cytogenetic, and molecular response; overall and event-free survival rates; and most frequency and severity of adverse reactions.

METHODS During May 2003 to May 2008, 33 newly-diagnosed chronic myeloid leukemia patients (25 adults, 8 children; <6 months from diagnosis) received a single daily oral dose of imatinib 400 mg from the time of study enrollment. Variables used: (1) to evaluate treatment efficacy: hematologic, cytogenetic, and molecular response; overall and event-free survival; and (2) to evaluate safety: presence of adverse reactions leading to definitive interruption of treatment or death.

RESULTS Complete hematologic response occurred in 100% of patients, major cytogenetic response in 90.9%, and complete cytogenetic response in 48.5%. Molecular response occurred in 36.4% of patients. With a mean follow-up of 39 months, overall survival was 96% and estimated five-year event-free survival was 85%. No adverse reactions occurred in 39.5% of patients. Adverse reactions most frequently observed were myelosuppression (24.2%) and digestive disorders (21.2%). These were followed, in decreasing order, by edema, primarily orbital (9.1%), skin depigmentation (3%), and cardiac arrhythmias (3%).

CONCLUSIONS In the present study, imatinib was effective first-line therapy for patients with newly-diagnosed chronic myeloid leukemia, as determined by overall and event-free survival rates. No severe adverse reactions were observed.

KEYWORDS Imatinib, chronic myeloid leukemia, cytogenetic response, molecular response, Cuba

INTRODUCTION: Recombinant human erythropoietin (RHuEPO) is an erythropoiesis stimulating agent (ESA) used to treat anemia in patients with total or relative erythropoietin deficit. In cancer patients, it is administered to optimize hemoglobin (Hb) levels, correct anemia and reduce the need for transfusions. Cuba produces a RHuEPO, registered in 1998 as ior®EPOCIM, that is widely used in the national public health system, mainly to treat patients with anemia due to chronic kidney disease (CKD).

OBJECTIVE: Evaluate the efficacy and safety of ior®EPOCIM in pediatric cancer patients with anemia following chemotherapy or radiotherapy. The working hypothesis posed an Hb increase ≥15 g/l in 70% of patients receiving ior®EPOCIM for 8 weeks.

METHODS: A Phase IV, multicenter, open clinical trial was conducted. Participants were 157 patients aged 1–19 years with anemia and cyto-histological diagnosis of cancer in any location. Patients received either 600 U/kg ior®EPOCIM intravenously, once weekly, or 150 U/kg ior®EPOCIM subcutaneously, 3 times a week, for 8 weeks. All patients had blood tests every week to determine hemoglobin and hematocrit, and reticulocyte and platelet counts. Mean number of transfusions required by patients during the treatment period was compared to the mean number of transfusions received in the preceding 8 weeks. Adverse events (AE) were recorded at the 4th and 8th weeks and classified by intensity and causality.

RESULTS: Hb levels rose ≥15 g/l in 68.8% of patients, and transfusion requirements decreased 17%. The most frequent adverse events were fever (19.3%), vomiting (10.2%) and flu-like syndrome (9.6%). Intensity of AE was predominantly mild. Only 7 AE were classified as very probably related to the product and none of those was severe.

CONCLUSIONS: ior®EPOCIM proved to be safe and effective at the doses and frequencies used in this patient population. As a result, this medication was recommended for use in all pediatric oncology and hematology services in the country.

Keywords: Erythropoietin, recombinant; anemia, cancer, pediatrics, medical oncology, Cuba