Patient population clinical trials

Special populations - Clinical trial and postmarketing experience suggest that debilitated patients or patients taking additional medications that decrease Gl motility may be at greater risk of serious complications of constipation. Therefore, appropriate caution and follow-up should be exercised if alosetron is prescribed for these patients. 

Many factors can interact with dmgs to make this problem worse. These include genetic factors, such as mutations in sodium, potassium and calcium channel genes that predispose people to repolarization failure [11-13]. This is the main explanation for the fact that dmgs with this side-effect have it in only a small fraction of the population. In principle, it should become possible to screen for such genetic predispositions to exclude such patients in clinical trials and to avoid treating them with drugs that interact in this way (Fig. 9.2). 

The evaluation of autoimmunity potential of drug candidates in animal studies would have value if the results could make an impact on the conduct of clinical trials during drug development, e.g., influence selecting patient population, clinical monitoring, dose selection and/or escalation, stopping criteria, or other safety decisions. 

A key element in planning and conducting clinical trials is to ensure that they have scientific validity and objectivity. This is particularly relevant with respect to Phase II and III studies, where it is desired to demonstrate a positive benefit to risk outcome. Responses to a drug among a patient population are rarely homogeneous and clear-cut. Thus, sound statistical principles must be applied in order to be able to distinguish significant effects from random events. 

DeVincenzo et al. 2008). Phase n clinical trials in naturally infected RSV patients were initiated in April 2008. ALN-RSVOl is expected to advance into the pediatric patient population by the second half of 2008. 

Anticoagulation in Stroke Due to LAA Disease Few clinical trials have been performed in this population. In the TOAST trial, a secondary analysis in patients with stroke due to LAA found favorable outcomes at 7 days in 54% of danaparoid-treated patients, compared to 38% of the placebo-treated group (p = 0.02). At 3 months, 68% of patients in the danaparoid group compared to 53% of those in the placebo group had favorable outcomes (p = 0.02). 

Upon stabilization, placement of a pulmonary artery (PA) catheter may be indicated based on the need for more extensive cardiovascular monitoring than is available from non-invasive measurements such as vital signs, cardiac rhythm, and urine output.9,10 Key measured parameters that can be obtained from a PA catheter are the pulmonary artery occlusion pressure, which is a measure of preload, and CO. From these values and simultaneous measurement of HR and blood pressure (BP), one can calculate the left ventricular SV and SVR.10 Placement of a PA catheter should be reserved for patients at high risk of death due to the severity of shock or preexisting medical conditions such as heart failure.11 Use of PA catheters in broad populations of critically ill patients is somewhat controversial because clinical trials have not shown consistent benefits with their use.12-14 However, critically ill patients with a high severity of illness may have improved outcomes from PA catheter placement. It is not clear why this was... 

Certain patient populations require special considerations due to their altered metabolism, unique volume of distribution, or increased risk for side effects.43 Although many of these patients are excluded from clinical trials in SE, the standard algorithm for SE still applies for these patients in terms of immediate care, assessment, and drugs (see Table 28-2). 

Clinical trial data supporting the use of specialty formulas in niche populations typically are unconvincing in terms of patient outcomes. 

Specialty formulas designed for use in specific clinical situations generally are much more expensive than standard polymeric formulas. Strong clinical trial data supporting use of these specialty formulas in niche populations typically are unconvincing in terms of patient outcomes. 

Phase 3 trials are large-scale clinical trials on populations numbering in the hundreds to thousands of patients. These are the critical trials that the drug maker runs to show that its new drug is both safe and efficacious in the target study population. If the phase 3 trials are successful, they will form the keystone elements of a New Drug Application... 

There are several areas of study that will help you understand the research topic. As a first step you will want to read the clinical protocol. The protocol describes the device or medication to be used, the patient populations under study, the statistical plan of the clinical trial, and the details of the disease state. If you want to understand the disease state or indication further, you may want to seek out a clinical investigator of the clinical trial or do some further reading about the disease. Understanding the patient population is a good way to understand the data that you will see and whether there is reason for concern when viewing the data. For example, if you were studying a medication to reduce hypertension, you would not be as worried if patient blood pressure data were elevated at baseline. You would expect to see this because you understand that hypertensive patients have high blood pressure. 

Time is a critical measure for clinical trial analysis. Time is captured in clinical trial databases in a study day variable. Study day can be defined as the number of days from therapeutic intervention to any given time point or event. By defining study day, you create a common metric for measuring time across a population of patients in a clinical trial. There can be a study day calculation for any time point of interest. Adverse event start, study termination, and clinical endpoint event date all make good choices for study day calculations. The study day calculation is performed with one of the two following approaches. 

---