Measuring the incremental cost of clinical cancer research.
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PURPOSE: To summarize evidence on the costs of treating patients in clinical trials and to describe the Cost of Cancer Treatment Study, an ongoing effort to produce generalizable estimates of the incremental costs of government-sponsored cancer trials. METHODS: A retrospective study of costs will be conducted with 1,500 cancer patients recruited from a randomly selected sample of institutions in the United States. Patients accrued to either phase II or phase III National Cancer Institute-sponsored clinical trials during a 15-month period will be asked to participate in a study of their health care utilization (n = 750). Costs will be measured approximately 1 year after their trial enrollment from a combination of billing records, medical records, and an in-person survey questionnaire. Similar data will be collected for a comparable group of cancer patients not in trials (n = 750) to provide an estimate of the incremental cost. RESULTS: Evidence suggests insurers limit access to trials because of cost concerns. Public and private efforts are underway to change these policies, but their permanent status is unclear. Previous studies found that treatment costs in clinical trials are similar to costs of standard therapy. However, it is difficult to generalize from these studies because of the unique practice settings, insufficient sample sizes, and the exclusion of potentially important costs. CONCLUSION: Denials of coverage for treatment in a clinical trial limit patient access to trials and could impede clinical research. Preliminary estimates suggest changes to these policies would not be expensive, but these results are not generalizable. The Cost of Cancer Treatment Study is an ongoing effort to provide generalizable estimates of the incremental treatment cost of phase II and phase III cancer trials. The results should be of great interest to insurers and the research community as they consider permanent ways to finance cancer trials. (+info)
Clinical trial designs for cytostatic agents: are new approaches needed?
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Preclinical data suggest that some new anticancer agents directed at novel targets demonstrate tumor growth inhibition but not tumor shrinkage. Such cytostatic agents may offer clinical benefits for patients in the absence of tumor shrinkage. In addition, lower doses of some of these agents may be just as effective as higher doses, implying that toxicity may not be an ideal end point for dose finding. Because of these factors, the sequence and design of traditional phase I, II, and III trials used for cytotoxic agents (which typically shrink tumors and in a dose-dependent manner) may not be appropriate for cytostatic agents. This article discusses options for modifying trial designs to accommodate cytostatic agents. Examples are given where these options have been tried or are currently being tried. Recommendations given for choosing among the trial designs depend on what is known preclinically about the agents (eg, does one have a validated and reproducible biologic end point that can be used to guide a dose escalation?), what is known about the patient population being studied (eg, does one have a well-documented historical progression-free survival rate at 1 year for comparison with the experience of the new agent?), and the numbers of agents and patients available for participation in trials. Planned and ongoing trials will test the utility of some of these new approaches. (+info)
Application of a new multinomial phase II stopping rule using response and early progression.
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PURPOSE: A multinomial stopping rule had previously been developed that incorporated both objective response and early progression into decisions to stop or continue phase II trials of anticancer agents. The purpose of this study was to apply the multinomial rule to two independent sets of phase II data to assess its utility in appropriately recommending early trial closure as compared with other stopping rules. MATERIALS AND METHODS: Data from completed phase II trials of the National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) and European Organization for Research and Treatment of Cancer Early Clinical Studies Group (ECSG) formed the basis of the study. Based on observed results for each trial, the recommendation of the multinomial stopping rule was applied, as was the recommendation of the actual stopping rule used (Fleming or Gehan). The appropriateness of the recommendations was evaluated based on interpretation of final study results. RESULTS: The standard and multinomial rules disagreed on early stopping in one of 16 NCIC CTG trials and in seven of 23 ECSG trials. In all cases, the standard rule advised continuing to the second stage whereas the multinomial rule advised stopping early because of excessive numbers of patients experiencing early disease progression. Final trial results indicated that the multinomial recommendation was appropriate, because in no study did final results lead to conclusions of activity. CONCLUSION: In this series of trials, the multinomial stopping rule performed more efficiently than the Fleming or Gehan rules in advising early stopping of trials. These results encourage continued exploration of this approach for phase II trials of cytotoxic and noncytotoxic anticancer agents. (+info)
Therapeutic angiogenesis in cardiology using protein formulations.
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Therapeutic angiogenesis in cardiovascular disease aims at improving myocardial function by increasing blood flow to ischemic myocardium that is not amenable to traditional forms of revascularization. Preclinical data have provided proof of the concept that angiogenic growth factors such as fibroblast growth factor 2 (FGF-2) and vascular endothelium growth factor (VEGF) may indeed improve myocardial flow and function when administered in ways that ensure prolonged tissue exposure to these short-lived molecules. Although other cytokines have been shown to enhance angiogenesis in vivo, FGF-2 and VEGF have been most widely studied and may serve as prototype proangiogenic drugs. Currently, several delivery techniques that are clinically applicable are being studied with respect to tissue distribution and retention as well as angiogenic efficacy of FGF-2 and VEGF. Although tissue distribution and retention of FGF-2 after intramyocardial injection compares favorably with other routes of administration, efficacy studies are not yet conclusive. At the same time, different protein- and gene-based formulations are being investigated. Arguments for and against protein and gene therapy are presented, showing that protein-based therapy seems to have advantages over gene therapy at the present time, although continuous efforts should be made to increase the tissue exposure time after a single administration of protein. While delivery systems and growth factor formulations are being improved, double-blind, placebo-controlled trials designed with existing animal data in mind, are needed to firmly establish the utility of therapeutic angiogenesis in cardiovascular disease. (+info)
Randomized trials of high dose chemotherapy for breast cancer.
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'Now is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning'Winston Churchill in a speech to the Canadian Senate and House of Commons, December 30, 1941. In laboratory models of cancer, dose of cytotoxic chemotherapy correlates with curative therapy, while cumulative dose is associated with longer survival for those who are not cured. These observations suggests a strategy of using high doses when cure is the objective but smaller doses over a prolonged period when palliation and survival are the goal. A strategy combining repetitive cycles of higher doses of cytotoxic therapy, followed by the optimal combination of hormonal and biological agents based on the tumor's receptors might contribute to both the highest possible cure rate and the longest survival. The development of bone marrow transplant (BMT) for leukemias, and its subsequent modification for support after high dose therapy for other malignancies, has a long, complex and emotional history in medicine. At least partly because of firmly held opinions and the way large randomized trials are funded in the United States, few American randomized trials of BMT or high dose therapy strategies have been completed. The vast majority of published randomized BMT and high dose studies are European. Interestingly, in contrast, two large American randomized trials of high dose chemotherapy for breast cancer had actually completed accrual. Accrual on a third was on target until the presentation of five very small or very early randomized trials at the American Society of Clinical Oncology meeting in May of 1999. Results from some of these trials, which were analyzed after a relatively brief follow-up, are too premature to allow definitive conclusions. Nevertheless, these data have been over and misinterpreted within the scientific and lay communities. The remaining studies included a limited number of patients, thus restricting the statistical power of the observations. The desire for quick answers impeded dispassionate analysis of the available data. The opportunity for collegial review of the data further deteriorated with another round of press coverage when the data from the South African adjuvant study were found to be unreliable. Rather than increasing commitment to accrual on randomized and appropriate pilot trials, accrual to the only large American study in existence at that time trickled to a halt. In response to press coverage, Susan Edmonds from the Fred Hutchinson Cancer Research Center observed that 'the NYT article tends to cast shadows generally on the therapy and those providing the therapy rather than pointing out early in the article (where the public will readily see it) that there are a number of very credible research institutions conducting research directed at breast cancer, some looking at high dose chemotherapy and stem cell transplantation.' Dr. Rodenhuis, presenting the large positive Dutch Randomized study (funded by the Dutch insurance industry) at ASCO in 2000, commented on the 'unreasonably high expectations until 1999' and 'unreasonably negative [opinion-ed] since 1999' for high dose adjuvant chemotherapy for breast cancer. (+info)
Short-term measures of relative efficacy predict longer-term reductions in human immunodeficiency virus type 1 RNA levels following nelfinavir monotherapy.
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We calculated the relative efficacy of treatment, defined as the rate of decline of virus levels in plasma during treatment relative to the rate of decline during highly potent combination therapy, in human immunodeficiency virus type 1 (HIV-1) patients treated for 56 days with different doses of the protease inhibitor nelfinavir. Relative efficacies based on the rate of decline of HIV-1 RNA levels in plasma over the first 14 to 21 days correlated with drug dose and viral load reduction by day 56. Calculation of relative treatment efficacies over the first 2 to 3 weeks of treatment can allow rapid assessment of new antiretroviral agents and dosing regimens, reducing the need to keep subjects in clinical trials on monotherapy for prolonged periods of time. Relative efficacy may also serve as a measure of treatment efficacy in patients in initiating established therapies. (+info)
The endotoxin-binding bactericidal/permeability-increasing protein (BPI): a target antigen of autoantibodies.
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The bactericidal/permeability-increasing protein (BPI) is an endotoxin-binding neutrophil leukocyte-granule protein with antibacterial and anti-endotoxin properties. A recombinant form of BPI (rBPI21) has been developed and is being tested as a therapeutic agent to treat gram-negative bacterial infections and exposure to gram-negative bacterial endotoxin. BPI is also a target antigen of anti-neutrophil cytoplasmic autoantibodies (ANCA). BPI-ANCA are present in cystic fibrosis, inflammatory bowel disease, vasculitis, and primary sclerosing cholangitis; presence of BPI-ANCA appears associated with a higher inflammatory disease activity and greater organ damage. BPI-ANCA as well as ANCA directed at other neutrophil-granule proteins may exacerbate inflammation by nonspecific effects of extracellular and cell-associated immune complexes. BPI-ANCA may further worsen inflammation by reducing the ability of BPI to promote clearance of gram-negative bacteria and bacterial-associated endotoxin. (+info)
Genotypic correlates of phenotypic resistance to efavirenz in virus isolates from patients failing nonnucleoside reverse transcriptase inhibitor therapy.
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Efavirenz (also known as DMP 266 or SUSTIVA) is a potent nonnucleoside inhibitor of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) activity and of HIV-1 replication in vitro and in vivo. Most patients on efavirenz-containing regimens have sustained antiviral responses; however, rebounds in plasma viral load have been observed in some patients in association with the emergence of mutant strains of HIV-1. Virus isolates from the peripheral blood mononuclear cells (PBMCs) of patients with such treatment failures, as well as recombinant viruses incorporating viral sequences derived from patient plasma, show reduced in vitro susceptibility to efavirenz in association with mutations in the RT gene encoding K103N, Y188L, or G190S/E substitutions. Patterns of RT gene mutations and in vitro susceptibility were similar in plasma virus and in viruses isolated from PBMCs. Variant strains of HIV-1 constructed by site-directed mutagenesis confirmed the role of K103N, G190S, and Y188L substitutions in reduced susceptibility to efavirenz. Further, certain secondary mutations (V106I, V108I, Y181C, Y188H, P225H, and F227L) conferred little resistance to efavirenz as single mutations but enhanced the level of resistance of viruses carrying these mutations in combination with K103N or Y188L. Viruses with K103N or Y188L mutations, regardless of the initial selecting nonnucleoside RT inhibitor (NNRTI), exhibited cross-resistance to all of the presently available NNRTIs (efavirenz, nevirapine, and delavirdine). Some virus isolates from nevirapine or delavirdine treatment failures that lacked K103N or Y188L mutations remained susceptible to efavirenz in vitro, although the clinical significance of this finding is presently unclear. (+info)