Priming and treatment with molgramostim (rhGM-CSF) in adult high-risk acute myeloid leukemia during induction chemotherapy: a prospective, randomized pilot study

Treatment strategies for pediatric acute myeloid leukemia

Therapeutic strategies utilized in recently completed Phase III clinical trials in children with de novo acute myeloid leukemia have led to long-term disease-free survival in 50 - 60% of children. This review describes the contributions from early intensification of therapy and postremission intensification using highly myelosuppressive chemotherapy strategies and discusses the controversial roles of allogeneic bone marrow transplantation, maintenance therapy and CNS irradiation. Current strategies focusing on the identification of critical biologic features and measurements of early response to therapy allow for greatly improved risk group stratification. Future improvements in the treatment of children with acute myeloid leukemia will depend on a better understanding of the biology of the disease, targeted therapeutic approaches directed to specific biologic targets, selective use of allogeneic transplantation and innovative clinical trial designs that will allow for the testing of an increasing number of new agents in increasingly small numbers of patients in defined risk groups.

Colony-stimulating factors in the management of neutropenia and its complications

Granulocyte colony-stimulating factor (CSF) and granulocyte-macrophage CSF are potent drugs used to increase neutrophil counts after myelosuppressive chemotherapy. However, in various indications, the use of CSFs has no clinical benefit with regard to morbidity or mortality from infectious complications, frequency of antibiotic use, or rate of hospitalization. Thus, the application of CSFs should be limited to indications with proven clinical benefits or evidence of cost-effectiveness. This review will provide an overview of the state-of-the-art use of CSFs in chemotherapy-associated neutropenia, transplantation, and bone marrow failure syndromes. In addition, recently developed drugs for accelerated hematopoietic recovery will be presented.

No benefit from adding GM-CSF to induction chemotherapy in transforming myelodysplastic syndromes: better outcome in patients with less proliferative disease

In this prospective randomized multicenter trial 93 patients, median age 72 years, with RAEB-t (n=25) and myelodysplastic syndrome (MDS)-AML (n=68) were allocated to a standard induction chemotherapy regimen (TAD 2+7) with or without addition of granulocyte-macrophage-CSF (GM-CSF). The overall complete remission (CR) rate was 43% with no difference between the arms. Median survival times for all patients, CR patients, and non-CR patients were 280, 550, and 100 days, respectively, with no difference between the arms. Response rates were significantly better in patients with serum lactate dehydrogenase (S-LDH) levels </=9.5 microkat/l, bone marrow cellularity </=70%, and WBC counts <4.0 x 10(9)/l, but S-LDH was the only variable independently associated with response by logistic regression analysis. Cox's regression analysis identified four significant prognostic factors for survival: bone marrow cellularity, S-LDH, cytogenetic risk group (International Prognostic Scoring System), and age. Only bone marrow cellularity (P=0.01) and S-LDH (P=0.0003) retained statistical significance in the log-rank test. Severe adverse events were significantly more common in the GM-TAD arm (P=0.01). Thus, addition of GM-CSF to chemotherapy showed no clinical benefit in terms of response but carried an increased risk for side effects. We present a clinically useful tool to predict response to chemotherapy and survival in elderly patients with transforming MDS, favoring patients with features of less proliferative disease.

Timed sequential chemotherapy with concomitant granulocyte colony-stimulating factor for high-risk acute myelogenous leukemia: a single arm clinical trial

BACKGROUND

The timed-sequential chemotherapy regimen consisting of etoposide, mitoxantrone and cytarabine (EMA) is an effective therapy for relapsed or refractory acute myelogenous leukemia (AML). We postulated that granulocyte colony-stimulating factor (G-CSF) might enhance the cytotoxicity of EMA by increasing the proportion of leukemic blasts in S-phase. We added G-CSF to EMA (EMA-G) for therapy of advanced high-risk AML patients.

METHODS

High-risk AML was defined as refractory, relapsed or secondary to either an antecedent hematologic disorder or exposure to cytotoxic agents. The patients were treated with one course of EMA-G consisting of mitoxantrone and cytarabine on days 1-3, and etoposide and cytarabine on days 8-10. G-CSF was started on day 4 and continued until absolute neutrophil count recovered.

RESULTS

Thirty patients were enrolled. The median age was 51 years (range, 25-75). Seventeen (61%) patients had unfavorable cytogenetic karyotypes. Twenty (69%) patients had secondary AML. Ten (34%) had relapsed disease. Four (14%) had refractory AML. Three (10%) patients died from febrile neutropenia and sepsis. Major non-hematologic toxicity included hyperbilirubimenia, renal insufficiency, mucositis, diarrhea, nausea and vomiting, skin rash. A complete remission was achieved in 13 (46%) patients. Median overall survival was 9 months (range, 0.5-66). Median relapse-free survival (RFS) for those who had a CR was 3 months (range, 0.5-63) with RFS censored at the time of allogeneic bone marrow transplantation or peripheral stem cell transplantation for 6 of the patients.

CONCLUSIONS

EMA-G is a safe and efficacious option for induction chemotherapy in advanced, high-risk AML patients. The activity of EMA may be increased if applied in patients with less advanced disease.

The pharmacodynamic basis for the increased antileukaemic efficacy of cytosine arabinoside-based treatment regimens in acute myeloid leukaemia with a high proliferative activity

The current study was initiated to explore the mechanisms underlying the previously demonstrated association between the proliferative activity of leukaemic blasts and the response to cytosine arabinoside (AraC)-based therapy in de novo acute myeloid leukaemia (AML). The activity of key enzymes of AraC metabolism-deoxycytidine kinase (DCK), cytidine deaminase (DCD) and polymerase alpha (PolyA) were determined in blast cells from 33 patients. In addition, formation and retention of intracellular levels of AraC triphosphate (AraCTP) and DNA incorporation of AraC were measured, as was the proliferative activity of leukaemic blasts by [3H]-TdR incorporation before and after stimulation with granulocyte-macrophage colony-stimulating factor (GM-CSF) or granulocyte CSF (G-CSF) for 48 h. AraC incorporation into the DNA (median 0.60 pmol/105 cells) was significantly related to the proliferative activity of AML blasts (r = 0.74, P < 0.001). Similarly, priming with GM-CSF or G-CSF increased both the proliferative activity of AML blasts by a median of 1.84- and 1.64-fold, respectively, and the incorporation of AraC into the DNA (1.29- and 1.40-fold respectively). In contrast, no relationship was found between the endogenous proliferative activity (EPA) and enzyme activities regulating AraC activation (DCK; median 4.70 pmol/min/mg protein), inactivation (DCD; median 2.92 pmol/min/mg protein) or inhibitory effects (PolyA; median 1.50 pmol/min/mg protein), nor the formation or retention of AraCTP (median 306.1 ng/107 cell and 1.6 h respectively). When samples were grouped according to EPA (more than or less than the median), slowly proliferating specimens had a higher response to cytokine priming for proliferative activity and incorporation of AraC into DNA. Clinical data of 15 patients were available. Although all eight patients with a high endogenous proliferative activity reached complete remission, only four out of seven patients with a low proliferative activity responded, whereas the other three patients were non-responders (P = 0.077).