The pharmaceutical development landscape faces persistent challenges of escalating costs, lengthy timelines, and high attrition rates that limit patient access to innovative therapies. Regulatory science has emerged as a critical discipline bridging fundamental drug discovery with clinical application, providing frameworks for evidence generation, risk-benefit assessment, and post-marketing evaluation. The integration of real-world evidence derived from diverse data sources—including electronic health records, claims databases, patient registries, and digital health platforms—offers transformative potential for accelerating drug development while maintaining rigorous safety and efficacy standards. This review examines the foundational principles of regulatory science in pharmaceutical innovation, including harmonized frameworks established through the International Council for Harmonisation, adaptive approval pathways such as breakthrough therapy designation and conditional marketing authorization, and the translational continuum from bench to bedside. Real-world data sources and methodological considerations for generating valid evidence are analyzed, with emphasis on study design, bias control, and data standardization essential for regulatory acceptance. Applications across the drug development lifecycle include optimizing trial design through external control arms, enhancing patient stratification, supporting label expansion, and strengthening post-marketing pharmacovigilance. Comparative evaluation demonstrates that real-world evidence-augmented development reduces time-to-market by 20-40%, improves cost efficiency, and enables assessment of long-term safety and effectiveness in diverse populations. Ethical considerations encompassing data privacy, transparency, reproducibility, and algorithmic bias require robust governance frameworks. Future perspectives highlight standardization initiatives, artificial intelligence integration for advanced analytics, and global regulatory convergence toward innovation ecosystems that maintain public trust while accelerating therapeutic advancement. The maturation of regulatory science incorporating real-world evidence represents a paradigm shift toward learning healthcare systems where evidence generation continuously informs therapeutic decision-making.