Clinical investigations remains the single most important medical tool to evaluate and compare various therapies. This includes the design and analysis for drug and vaccine development, and for evaluation of the efficacy and safety of therapeutic agent and vaccines. The issues involved include early stopping (interim analysis), censoring missing data, problems of compliance, competing trials, intermediate endpoints, surrogate markers univariate and multivariate survival analysis. Among the issues of interest are: the design of clinical investigations beginning with an understanding of drug mechanisms through pharmacokinetics/dynamics studies, and the assessment of drug safety and efficiency (i.e., the design of Phase I, III, IV studies). We are also interested in the design of prevention and vaccine trials. A particular challenging problem in the design of trials with multivariate endpoints.