Clinical data gap between phase III clinical trials (pre-marketing) and phase IV (post-marketing) studies: evaluation of etanercept in rheumatoid arthritis. (73/449)

BACKGROUND: There are fundamental differences in design between phase III clinical trials and phase IV post-marketing studies that involve patient characteristics, the clinical setting (environment) and the manner of drug use. As well, many phase IV studies are extensions of randomized clinical trials (RCTs) and suffer from selection bias. OBJECTIVE: To determine if the data obtained from RCTs of etanercept (Enbrel) in the treatment of rheumatoid arthritis would be representative of the effects attainable in community practice. METHOD: An analysis was conducted comparing data from published RCTs of etanercept use in rheumatoid arthritis patients with data collected in a community based cohort study that was not an extension of an RCT. RESULTS: Baseline clinical data, such as tender or painful joint count, patient's global assessment, the heath assessment questionnaire, physical and mental component summary of the SF-36, and rheumatoid arthritis drug profile were significantly different between the patients receiving etanercept in the phase IV community cohort study and the patients enrolled in the RCTs. Differences in the baseline data for the control patients were also noted amongst the RCT studies. The treatment outcome, American College of Rheumatology (ACR) response rate of 20%, 50% and 70% at 6 month, was the same between the cohort study and the RCTs, but at 12 months the clinical response was less for the community based patients than for the RCT patients. At 6 months there were fewer withdrawals involving community-based patients than RCT patients due to less frequent withdrawals associated with lack of efficacy. At 12 months the withdrawal rate due to either a lack of efficacy or from adverse events was similar between data sets. CONCLUSION: The data from the etanercept phase III RCTs may not reflect the characteristics of patients using etanercept in community practice, nor the clinical outcomes observed by RA patients at 12 months. These discrepancies may be derived from methodological differences in study design and patient selection. On the other hand, outcomes such as withdrawal rates at 12 months appear comparable between the two types of populations.  (+info)

In vitro activity of linezolid against key gram-positive organisms isolated in the united states: results of the LEADER 2004 surveillance program. (74/449)

Since the approval of linezolid in 2000, sporadic reports of resistance have been given and a greater understanding of the underlying mechanisms of resistance has been gained. However, since these developments, an updated status of the in vitro activity of linezolid against gram-positive organisms from the United States has not been reported. The LEADER 2004 surveillance initiative was undertaken to obtain current and representative data on the activity of linezolid against key species, including isolates with significant resistance phenotypes. Organisms were isolated during 2004 and included 2,872 Staphylococcus aureus, 496 coagulase-negative staphylococcus (CNS), 428 Enterococcus faecalis, 196 Enterococcus faecium, and 422 Streptococcus pneumoniae isolates. All S. aureus isolates (54.2% oxacillin resistant) were susceptible to linezolid (MIC90 = 2 microg/ml); MIC distributions were consistent, regardless of oxacillin or multidrug resistance status. For CNS, one nonsusceptible isolate was encountered (Staphylococcus epidermidis; MIC = 32 microg/ml), but overall, the MIC(90) (1 microg/ml) was lower than that obtained with S. aureus. For E. faecalis and E. faecium, 99.5% and 96.4% of isolates, respectively, were linezolid susceptible. Both species had an MIC90 of 2 microg/ml, and MIC distributions did not vary with the vancomycin susceptibility status of the populations analyzed. Linezolid nonsusceptibility was not encountered among the S. pneumoniae isolates. These findings indicate that linezolid nonsusceptibility has remained rare among staphylococci and uncommon and sporadic among enterococci. Nonetheless, careful and ongoing monitoring of the in vitro effectiveness of linezolid will be needed so that any changes to the current status may be detected as soon as possible.  (+info)

The quality of sulphadoxine-pyrimethamine and amodiaquine products in the Kenyan retail sector. (75/449)

BACKGROUND AND OBJECTIVE: Malaria is a disease of major public health importance in Kenya killing 26,000 children under 5 years of age annually. This paper seeks to assess the quality of sulphadoxine-pyrimethamine (SP) and amodiaquine (AQ) products available over-the-counter to communities in Kenya as most malaria fevers are self-medicated using drugs from the informal retail sector. METHODS: A retail audit of 880 retail outlets was carried in 2002 in four districts in Kenya, in which antimalarial drug stocks and their primary wholesale sources were noted. In addition, the expiry dates on audited products and the basic storage conditions were recorded on a proforma. The most commonly stocked SP and AQ products were then sampled from the top 10 wholesalers in each district and samples subjected to standard United States Pharmacopoeia (USP) tests of content and dissolution. RESULTS AND DISCUSSION: SP and AQ were the most frequently stocked antimalarial drugs, accounting for approximately 75% of all the antimalarial drugs stocked in the four districts. Of 116 SP and AQ samples analysed, 47 (40.5%) did not meet the USP specifications for content and/or dissolution. Overall, approximately 45.3% of SP and 33.0% of AQ samples were found to be sub-standard. Of the sub-standard SP products, 55.2% were suspensions while 61.1% of the substandard AQ products were tablets. Most SP failures were because of the pyrimethamine component. CONCLUSION: There is a need to strengthen post-marketing surveillance systems to protect patients from being treated with sub-standard and counterfeit antimalarial drugs in Kenya.  (+info)

Monitoring device safety in interventional cardiology. (76/449)

OBJECTIVE: A variety of postmarketing surveillance strategies to monitor the safety of medical devices have been supported by the U.S. Food and Drug Administration, but there are few systems to automate surveillance. Our objective was to develop a system to perform real-time monitoring of safety data using a variety of process control techniques. DESIGN: The Web-based Data Extraction and Longitudinal Time Analysis (DELTA) system imports clinical data in real-time from an electronic database and generates alerts for potentially unsafe devices or procedures. The statistical techniques used are statistical process control (SPC), logistic regression (LR), and Bayesian updating statistics (BUS). MEASUREMENTS: We selected in-patient mortality following implantation of the Cypher drug-eluting coronary stent to evaluate our system. Data from the University of Michigan Consortium Bare-Metal Stent Study was used to calculate the event rate alerting boundaries. Data analysis was performed on local catheterization data from Brigham and Women's Hospital from July 1, 2003, shortly after the Cypher release, to December 31, 2004, including 2,270 cases with 27 observed deaths. RESULTS: The single-stratum SPC had alerts in months 4 and 10. The multistrata SPC had alerts in months 5, 10, and 18 in the moderate-risk stratum, and months 1, 4, 7, and 10 in the high-risk stratum. The only cumulative alerts were in the first month for the high-risk stratum of the multistrata SPC. The LR method showed no monthly or cumulative alerts. The BUS method showed an alert in the first month for the high-risk stratum. CONCLUSION: The system performed adequately within the Brigham and Women's Hospital Intranet environment based on the design goals. All three cumulative methods agreed that the overall observed event rates were not significantly higher for the new medical device than for a closely related medical device and were consistent with the observation that the initial concerns about this device dissipated as more data accumulated.  (+info)

Cardiac resynchronization devices: the Food and Drug Administration's regulatory considerations. (77/449)

Cardiac resynchronization therapy (CRT) devices have been studied clinically since 1998, and have been on the U.S. market since the Food and Drug Administration (FDA) approval of the first product in 2001. Since that time, the FDA has approved many different models from three different manufacturers, representing the first and second generations of these products. All of these products have undergone the FDA pre-market approval process, which examines the safety and effectiveness of the devices for their intended use. Over the last several years, the FDA has adapted recommendations for CRT clinical trials based on an evolving understanding of what these devices can achieve. This paper will outline the dynamic nature of the FDA's approval process for CRT devices and briefly review the clinical trial designs for the first generation devices.  (+info)

Safety analyses of adalimumab (HUMIRA) in global clinical trials and US postmarketing surveillance of patients with rheumatoid arthritis. (78/449)

OBJECTIVE: To assess the safety of adalimumab in global clinical trials and postmarketing surveillance among patients with rheumatoid arthritis (RA). METHODS: Safety data for adalimumab treated patients from randomised controlled trials, open label extensions, and two phase IIIb open label trials were analysed. In addition, postmarketing spontaneous reports of adverse events in the United States were collected following Food and Drug Administration approval of adalimumab on 31 December 2002. RESULTS: As of 15 April 2005, the RA clinical trial safety database analysed covered 10,050 patients, representing 12,506 patient-years (PYs) of adalimumab exposure. The rate of serious infections, 5.1/100 PYs, was comparable to that reported on 31 August 2002 (4.9/100 PYs), and to published reports of RA populations naive to anti-tumour necrosis factor (TNF) therapy. Following implementation of tuberculosis (TB) screening in clinical trials, the rate of TB decreased. There were 34 cases of TB as of this analysis (0.27/100 PYs). The standardised incidence ratio for lymphoma was 3.19 (95% CI 1.78 to 5.26), consistent with the observed increased incidence in the general RA population. As of 30 June 2005, there were an estimated 78 522 PYs of exposure to adalimumab in the US postmarketing period. Seventeen TB cases were spontaneously reported (0.02/100 PYs) from the US. Rates of other postmarketing events of interest, such as congestive heart failure, systemic lupus erythematosus, opportunistic infections, blood dyscrasias, lymphomas, and demyelinating disease, support observations from clinical trials. CONCLUSION: Analyses of these data demonstrate that long term adalimumab treatment is generally safe and well tolerated in patients with RA.  (+info)

Value of postmarketing surveillance studies in achieving a complete picture of antimigraine agents: using almotriptan as an example. (79/449)

Randomised controlled trials cannot collect all the data relevant for use in everyday clinical practice because drug exposure is limited, endpoints are restricted and some patient populations are excluded. Postmarketing surveillance (PS) studies can add important information for real-world clinical practice. Acute migraine therapy with almotriptan 12.5 mg was evaluated in 4 PS studies, 2 conducted in Spain, 1 in Germany and 1 in France. Almotriptan was associated with a high rate of treatment response and was well tolerated in all 4 studies. In the Spanish and German studies, 2-hour pain-relief, 2-hour pain-free, and sustained painfree rates were enhanced when patients treated mild pain. Patient satisfaction with almotriptan, assessed in the German and French studies, was high and the majority of patients preferred almotriptan to their previous acute migraine therapy. In conclusion, PS studies augment our knowledge of antimigraine therapy, giving a more complete picture of how such agents work in the general population.  (+info)

Retrospective analysis of utilization patterns and cost implications of coxibs among seniors in Quebec, Canada: what is the potential impact of the withdrawal of rofecoxib? (80/449)

OBJECTIVE: In September 2004, the manufacturer of rofecoxib announced a voluntary worldwide withdrawal of the drug. The impact of this withdrawal on drug budgets is unclear. This study evaluated average daily doses and costs of rofecoxib and celecoxib and concomitant use of gastroprotective agents (GPAs) in elderly patients with osteoarthritis (OA) or rheumatoid arthritis (RA) in Quebec, prior to the rofecoxib withdrawal. METHODS: This retrospective cohort study used prescription drug and medical service data from the Quebec government health agency administrative database and included coxib users > or =66 years of age with OA or RA who filled > or =3 consecutive rofecoxib or celecoxib prescriptions in 2001-2002. Results were adjusted for gastrointestinal risk factors and other patient baseline characteristics. RESULTS: Data were analyzed for 11,975 rofecoxib and 12,480 celecoxib users. Mean daily dosages were 20.7 mg for rofecoxib and 231.3 mg for celecoxib. Rofecoxib users consumed a mean +/- SD of 0.95 +/- 0.43 pills per day, and celecoxib users took 1.34 +/- 0.65 pills per day. Mean +/- SD unadjusted daily acquisition costs were $1.18 +/- $0.53 (Canadian) for rofecoxib and $1.45 +/- $0.74 for celecoxib. After adjusting for patient baseline characteristics, the mean daily acquisition cost for rofecoxib was $0.25 lower than for celecoxib. Rofecoxib users were less likely than celecoxib users to fill a GPA coprescription (odds ratio 0.88; 95% confidence interval 0.81, 0.95). Subgroup analyses yielded comparable results. CONCLUSION: Celecoxib appears to be a more expensive therapeutic option than rofecoxib due to a relatively higher daily dose and tablet consumption.  (+info)