Neutropenia and neoplasia: an overview of the pharmacoeconomics of sargramostim in cancer therapy

GM-CSF: An immune modulatory cytokine that can suppress autoimmunity

GM-CSF was originally identified as a colony stimulating factor (CSF) because of its ability to induce granulocyte and macrophage populations from precursor cells. Multiple studies have demonstrated that GM-CSF is also an immune-modulatory cytokine, capable of affecting not only the phenotype of myeloid lineage cells, but also T-cell activation through various myeloid intermediaries. This property has been implicated in the sustenance of several autoimmune diseases like arthritis and multiple sclerosis. In contrast, several studies using animal models have shown that GM-CSF is also capable of suppressing many autoimmune diseases such as Crohn's disease, Type-1 diabetes, Myasthenia gravis and experimental autoimmune thyroiditis. Knockout mouse studies have suggested that the role of GM-CSF in maintaining granulocyte and macrophage populations in the physiological steady state is largely redundant. Instead, its immune-modulatory role plays a significant role in the development or resolution of autoimmune diseases. This is mediated either through the differentiation of precursor cells into specialized non-steady state granulocytes, macrophages and dendritic cells, or through the modulation of the phenotype of mature myeloid cells. Thus, outside of myelopoiesis, GM-CSF has a profound role in regulating the immune response and maintaining immunological tolerance.

Cancer vaccines entering Phase III clinical trials

The last 10 years have seen a growth in the number of tumour antigens identified from immune responses raised in patients. The discovery that tumours can be recognised by the immune system stimulated a great deal of work characterising the molecular mechanisms underlying immune recognition. This in turn has led to an impressive array of immunological approaches to the generation of cancer vaccines; these range from molecularly defined T cell epitopes, antibody-based vaccines, cytokine therapies, immune modulators and DNA vaccines, to whole cell vaccines and, more recently, combinations of these methods. Many of these approaches have entered Phase I/II trials and have shown interesting clinical results. Moreover, they have extended our knowledge of the immune system and our understanding of the mechanisms required to design a successful cancer vaccine. This review outlines some of the approaches that have led to some of these vaccines entering Phase III clinical trials, discusses their modes of action and reports on their current status in trial.

Treatment of acute myelogenous leukemia in older adults

The overall strategy for the treatment of older adults is summarized in Table 8. Soon after the birth of effective chemotherapy for acute leukemia, the perspective for all patients was summarized as follows: 'With all humility it may be claimed that there are, at least, grounds for hope and encouragement in this recently acquired ability occasionally to halt for a while the formerly unrelenting malignant process known as acute leukemia'. In reviewing the overall survival data for older adults one may feel that we are at a similar juncture in assessing the outcome for this particular population. It is hoped that some of the potential advances may provide greater hope and improved results over the next decade.

Cost analyses of adjunct colony stimulating factors for acute leukemia: can they improve clinical decision making

Colony stimulating factors reduce the duration of neutropenia following intensive chemotherapy in a variety of settings, but the advantages in the management of leukemia are inconclusive. The variations in clinical results and the high costs of granulocyte colony-stimulating factor (G-CSF) and granulocyte macrophage colony-stimulating factor (GM-CSF) have led to confusion over appropriate use for leukemia patients. In this paper, we reviewed published information on costs and cost-effectiveness of growth factors for childhood and adult leukemia patients. Medline and Healthstar databases were searched for original research articles that contain cost or cost-effectiveness analyses of G-CSF (filgrastim) and GM-SCF (sargramostim) in oncology cooperative group trials. Published manuscripts and abstracts presented at national or international oncology conferences were included. The cost of adjunct treatment was evaluated in two studies of pediatric ALL, one study of adult AML, and two studies of AML in older adults (>55 years). The use of G-CSF for children with ALL was associated with reductions in days to ANC recovery, fewer documented infections, a shorter duration of hospitalization, and small (but not significant) additional costs. In adult AML patients, benefits included a shortening of the duration of neutropenia and hospital stays, a lower incidence of infection and febrile episodes, less use of antibiotics, and cost savings of $2,230 and $2,310 in two studies and an increase if $120 in the third study. This summary suggests that economic analyses can provide useful information to assist clinical decision-making. For pediatric ALL patients, this information indicates that G-CSF use is unlikely to have significant cost implications, and its use should be based on clinical considerations. In studies of adult and older adult AML patients, both GM-CSF and G-CSF have clinical benefits and can be expected to lead to a decrease in overall costs.