Clinical trials significance levels

The number of subjects planned to be enrolled, if more than one site the numbers of enrolled subjects projected for each trial site should be specified. Reason for choice of sample size include calculations of the statistical power of the trial, the level of significance to be used and the clinical justification. 

A very common analysis in clinical trials involves the analysis of two binomial variables to see if there is a statistically significant association between them. A binomial variable is one that can have only one of two values. For example, let s assume that we have a variable called treatment whose value is either a 1 to indicate active drug therapy or a 0 to indicate placebo. We also have a variable called headache whose value is a 1 if the patient experiences headache after therapy and a 0 if not. What we want to know is whether a change in the level of therapy is significantly associated with a change in the level of headache. The 2x2 table looks like this ... 

A study of GSK1278863A (structure undisclosed) in healthy adult subjects for the safety, tolerability, pharmacokinetics, and pharmacodynamics of repeat oral doses up to 300 mg for 14 days has also been completed [69]. Finally, AKB-6548 (structure undisclosed) has completed Phase la clinical trials in 48 healthy volunteers for the potential treatment of anemia. Preliminary results claim that doses that significantly increase plasma EPO without raising VEGF levels were identified and that further clinical trials are planned [70]. 

IFN-x is currently generating considerable clinical interest. It induces effects similar to type I interferon, but it appears to exhibit significantly lower toxicity. Thus, it may prove possible to use this interferon safely at dosage levels far greater than the maximum dosage levels applied to currently used type I interferons. This, however, can only be elucidated by future clinical trials. 

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