How Can the Evidence from Global Large-scale Clinical Trials for Cardiovascular Diseases be Improved?

<p>Abstract</p> <p>Background</p> <p>Clinical investigations are important for obtaining evidence to improve medical treatment. Large-scale clinical trials with thousands of participants are particularly important for this purpose in cardiovascular diseases. Conducting large-scale clinical trials entails high research costs. This study sought to investigate global trends in large-scale clinical trials in cardiovascular diseases.</p> <p>Findings</p> <p>We searched for trials using clinicaltrials.gov (URL: <url>http://www.clinicaltrials.gov/</url>) using the key words 'cardio' and 'event' in all fields on 10 April, 2010. We then selected trials with 300 or more participants examining cardiovascular diseases. The search revealed 344 trials that met our criteria. Of 344 trials, 71% were randomized controlled trials, 15% involved more than 10,000 participants, and 59% were funded by industry. In RCTs whose results were disclosed, 55% of industry-funded trials and 25% of non-industry funded trials reported statistically significant superiority over control (p = 0.012, 2-sided Fisher's exact test).</p> <p>Conclusions</p> <p>Our findings highlighted concerns regarding potential bias related to funding sources, and that researchers should be aware of the importance of trial information disclosures and conflicts of interest. We should keep considering management and training regarding information disclosures and conflicts of interest for researchers. This could lead to better clinical evidence and further improvements in the development of medical treatment worldwide.</p

Funding and infrastructure among large-scale clinical trials examining cardiovascular diseases in Japan: evidence from a questionnaire survey

<p>Abstract</p> <p>Background</p> <p>Large-scale clinical trials with thousands of participants are often needed to evaluate the risk reductions of cardiac events and/or death. Many recent clinical trials have evaluated the incidences of cardiac events using hard endpoints, especially in cardiovascular and metabolic medicine. A high investigation cost is involved in conducting a large-scale clinical trial, and obtaining sufficient funding is essential. The infrastructural environment of clinical trials is currently inadequate in Japan. We conducted a questionnaire-based survey to address this issue. The present study sought to clarify the current situation surrounding large-scale clinical trials in terms of funding and infrastructure, and to inform discussion about improving the financial and infrastructural situation for clinical trials.</p> <p>Methods</p> <p>We sent questionnaires to 119 sponsors of large-scale clinical trials between August 2007 and December 2007, and between July 2009 and August 2009. Answers to each question were summarized and data were statistically analyzed.</p> <p>Results</p> <p>We received responses from the sponsors of 63 (52.9%) out of 119 trials to which questionnaires were sent. The results revealed that 25 trials (39.7%) were funded by foundations, and 21 trials (33.3%) were funded by public agencies. All of the foundations involved in conducting clinical trials, where funding sources were specified, were funded by private organizations such as pharmaceutical companies. All of the clinical trials with a cost of JPY 300 million (USD 3.27 million) or more were funded by private organizations, and none were funded solely by public agencies. The sponsors of 23 trials (36.5%) responded that the trial was 'not registered' to clinical trial registry.</p> <p>Conclusions</p> <p>The questionnaire responses revealed that there were still many trials whose funding sources were unclear and many sponsors were unaware of their responsibilities in managing and/or financing the costs of clinical trials. These findings indicate that further discussion is required to establish appropriate frameworks and/or rules regarding funding, while considering conflicts of interest. This discussion should take place as soon as possible to facilitate appropriate clinical trials.</p

Limited accessibility to designs and results of Japanese large-scale clinical trials for cardiovascular diseases

<p>Abstract</p> <p>Background</p> <p>Clinical evidence is important for improving the treatment of patients by health care providers. In the study of cardiovascular diseases, large-scale clinical trials involving thousands of participants are required to evaluate the risks of cardiac events and/or death. The problems encountered in conducting the Japanese Acute Myocardial Infarction Prospective (JAMP) study highlighted the difficulties involved in obtaining the financial and infrastructural resources necessary for conducting large-scale clinical trials. The objectives of the current study were: 1) to clarify the current funding and infrastructural environment surrounding large-scale clinical trials in cardiovascular and metabolic diseases in Japan, and 2) to find ways to improve the environment surrounding clinical trials in Japan more generally.</p> <p>Methods</p> <p>We examined clinical trials examining cardiovascular diseases that evaluated true endpoints and involved 300 or more participants using Pub-Med, Ichushi (by the Japan Medical Abstracts Society, a non-profit organization), websites of related medical societies, the University Hospital Medical Information Network (UMIN) Clinical Trials Registry, and clinicaltrials.gov at three points in time: 30 November, 2004, 25 February, 2007 and 25 July, 2009.</p> <p>Results</p> <p>We found a total of 152 trials that met our criteria for 'large-scale clinical trials' examining cardiovascular diseases in Japan. Of these, 72.4% were randomized controlled trials (RCTs). Of 152 trials, 9.2% of the trials examined more than 10,000 participants, and 42.8% examined between 1,000 and 10,000 participants. The number of large-scale clinical trials markedly increased from 2001 to 2004, but suddenly decreased in 2007, then began to increase again. Ischemic heart disease (39.5%) was the most common target disease. Most of the larger-scale trials were funded by private organizations such as pharmaceutical companies. The designs and results of 13 trials were not disclosed.</p> <p>Conclusions</p> <p>To improve the quality of clinical trials, all sponsors should register trials and disclose the funding sources before the enrolment of participants, and publish their results after the completion of each study.</p

Increased inosine 5{prime}-monophosphate dehydrogenase gene expression in replicating cells: A response to growth factors, not to changes in cell cycle parameters

The authors have analyzed levels of inosine 5{prime}-monophosphate dehydrogenase (IMPDH; E.C. 1.1.1.205) type II mRNA levels in a human melanoma cell line, SK-MEL-131, and a Chinese hamster ovary cell line synchronously progressing through the cell cycle following treatment with aphidicolin. Following release from the aphidicolin block at the G{sub 1}-S phase boundary, the type II IMPDH gene was found to be constitutively expressed at a similar level during all stages of the cell cycle. To analyze growth regulation, as opposed to cell cycle regulation, stable SK-MEL-131 transfectants that express a type II IMPDH-promoted heterologous construct were assayed following deprivation of serum growth factors and after restimulation with fresh serum. Serum deprivation resulted in down-regulation of both steady state type II IMPDH mRNA levels and promoter activity, while restimulation with serum resulted in up-regulation of these parameters. These findings support the conclusion that the increase in IMPDH type II gene expression in replicating cells is mainly due to growth factor regulation rather than changes in cell cycle parameters and that this regulation is mediated primarily by a transcriptional mechanism. The increased level of IMPDH expression and activity found in many tumors may therefore also be due to a transcriptionally mediated response to growth factors