This book overviews the fundamental aspects, challenges, and development strategies for biological drug entities. It is divided into 5 parts, covering general aspects in the development of biologics (Part 1) and challenges and strategies in the development of specific types of biologics  (Parts 2-5). In the overview section, contributing authors discuss the development process, safety and clinical assessments, manufacturing, and regulatory and intellectual property issues. Following this opening, the major classes of biologics are discussed: proteins and peptides, vaccines, oligonucleotides, and gene and regenerative medicines. A concluding section details administration and delivery routes and systems. The book incorporates both lessons learned and future directions to make for a valuable resource and reference for pharmaceutical scientists involved in the dynamic field of biologics.