What are biologics and how do they differ from traditional pharmaceuticals?

Biologics are agents obtained from, synthesized in, or constructed using biological sources. Biological agents include fluids (blood and blood components), solids (tissues, feces), proteins (vaccines, antibodies), cells, or genetic material. The primary difference between biologic agents and traditional pharmaceuticals is that the former are substances either extracted or produced from biological entities, while the latter are totally synthesized from molecular components via chemical reactions. 

Biologics can be artificially designed or altered – CAR-T cells, containing an artificially designed and assembled chimeric antigen receptor expressed by selected and expanded cells initially derived from a biological source, are a perfect example of how laboratory manipulations take biological components and assemble them into an agent. Biologics can also incorporate synthetic elements – for example, a synthetic nanoparticle can be used as a vector for a biologic. 

As biological entities, biologics are subject to more inherent variability (in form, function, and efficacy) than totally synthesized pharmaceuticals. They are also more susceptible to small changes in environmental conditions, whether during production, storage, or use. These factors contribute to an increased level of uncertainty surrounding biologics versus traditional pharmaceutical agents (which have known and well-defined structural and kinetic properties). Biologics are therefore subject to different quality control/assurance regulatory standards than traditional pharmaceutical agents.