In clinical trials, monitoring accumulating data at regular intervals is essential for balancing ethical and financial considerations against scientific rigor. This comprehensive second edition reflects the remarkable evolution in adaptive clinical trial methodology over the past two decades. Since publication of the first edition, these approaches have transformed from theoretical concepts to widely accepted practices, now endorsed by regulatory authorities, including formal FDA guidance. Features * Eleven entirely new chapters, including optimal design construction, delayed 'pipeline' data accommodation, and multiple comparison procedures * Eight dedicated chapters on adaptive methods including sample size re-assessment, seamless Phase II/III trials, multi-arm multi-stage trials, and enrichment designs * Exact methods for binary and Poisson data with applications to vaccine trials * Expanded discussion of binding versus non-binding futility boundaries for enhanced decision-making *