Chapters 1-4 concern statistical methods in designing and analyzing data for survival clinical trials and predicting trial duration. Chapters 5-7 concern statistical methods in clinical trials with sequential parallel designs which have been proposed for trials with high placebo response rates which can lead to a higher failure rate in drug development. Utilizing Box and Muller (1958) one of the most popular methods of generating standard normal random variable using two independent uniform (0 1) deviates a new method is proposed in Chapter 8 to combine two p-values from two disjoint samples for designing a trial with two stages.