The part of medical science related to the application of drugs and other remedies for curing or healing disease is known as Therapeutics. Therapeutics focuses on the correlation of the actions and effects of drugs and other chemical agents with the physiological, biochemical, microbiological, immunological, or behavioral factors influencing disease. It also considers how disease may modify the pharmacokinetic properties of a drug by altering its absorption into the systemic circulation and/or its disposition. Each of these areas is closely interwoven with the subject matter and experimental techniques of physiology, biochemistry, cellular and molecular biology, microbiology, immunology, genetics, and pathology.

Pharmacokinetics deals with the absorption, distribution, and excretion of drugs. Pharmacodynamic and pharmacokinetic aspects of action of chemical agents also apply to related areas of study, including toxicology and therapeutics.

The categories of therapeutic biological products regulated by CDER (under the FDC Act and/or the PHS Act, as appropriate) include the following:

• Monoclonal antibodies for in vivo use.
• Most proteins intended for therapeutic use, including cytokines (e.g., interferons), enzymes (e.g. thrombolytics), and other novel proteins, except for those that are specifically assigned to the Center for Biologics Evaluation and Research (CBER) (e.g., vaccines and blood products). This category includes therapeutic proteins derived from plants, animals, humans, or microorganisms, and recombinant versions of these products.  Exceptions to this rule are coagulation factors (both recombinant and human-plasma derived).
• Immunomodulators (non-vaccine and non-allergenic products intended to treat disease by inhibiting or down-regulating a pre-existing, pathological immune response).
• Growth factors, cytokines, and monoclonal antibodies intended to mobilize, stimulate, decrease or otherwise alter the production of hematopoietic cells in vivo.

Gene Therapy
Genes that are carried on chromosomes are the basic physical and functional units of heredity. Genes are specific sequences of bases that encode instructions on how to make proteins. Although genes get a lot of attention, it’s the proteins that perform most life functions and even make up the majority of cellular structures. When genes are altered so that the encoded proteins are unable to carry out their normal functions, genetic disorders can result.
Gene therapy is a technique for correcting defective genes responsible for disease development. Researchers may use one of several approaches for correcting faulty genes:

• A normal gene may be inserted into a nonspecific location within the genome to replace a nonfunctional gene. This approach is most common.
• An abnormal gene could be swapped for a normal gene through homologous recombination.
• The abnormal gene could be repaired through selective reverse mutation, which returns the gene to its normal function.
• The regulation (the degree to which a gene is turned on or off) of a particular gene could be altered.