This week explores the early phases of drug discovery. As outlined previously, the starting point is always the needs of the patient and their biomedical realities. Understanding disease biology is a critical next step and sets the scene for mapping the context for immune response and the origins of ill health and how the progression of disease can be controlled or arrested. Case studies, particularly in the context of tuberculosis (TB), demonstrate the rationale behind molecular biology studies of the pathogen and the host. Key concepts such as the essentiality and vulnerability of targets and their 'druggability' are introduced. Medicinal chemistry drives the chemical modification of drug-like molecules to improve their activity and safety. The various tools and approaches that the medicinal chemist has at their disposal, including the value of the screening cascade, will be discussed.

This week picks up the drug discovery and development story at the point at which promising drug candidates have already been identified. The crucial importance in this phase of investigating the pharmacokinetics and pharmacodynamics of potential drugs is introduced, as these are key parameters for the effectiveness of a new drug and a positive patient experience. These properties have a bearing on bioavailability and metabolic processes and provide a backdrop for animal model studies, and the extent to which the biological properties of the drug are retained in mammalian systems. The ethical considerations and technological advances pertaining to in vivo testing are discussed. Drug testing, safety profiling, and toxicology and efficacy in preparation for clinical trials are presented, and an introduction to process optimization and API manufacturing is also discussed.

This week outlines and examines the clinical development phase. Once a drug candidate has successfully progressed through the phases outlined previously, it qualifies for filing as an Investigational New Drug (IND) and a Clinical Trial Application (CTA) and the accompanying review process. An overview is given of the regulatory framework governing this, and a description of the various phases of clinical trials. The extensive teamwork that is required during the clinical trial is outlined, as well as the various role-players in this process, and some of the critical aspects, such as the submission and approval process, protocols that need to be established, informed consent and site management, are described. Finally, we look to the future and consider how new technologies are changing the face of drug discovery and development and how this may ultimately bring newer and safer medicines to the patient more rapidly.