- What is the impact of small protein design?
- What are the advantages/disadvantages of biologics vs small molecule drugs?
Currently, there are two classes of therapeutic agents - biologics and small molecule drugs. Classical drug discovery efforts generally target small molecules (average molecular weight is ~500) as therapeutic agents. These are advantageous because they are generally easy to synthesize and can be administered orally. Furthermore, small molecule drugs can be designed as either agonists or antagonists of biological processes for use against either extracellular or intracellular targets. Unfortunately, small molecules cannot presently modulate all biological targets with the specificity and potency required for useful therapeutics. Additionally, the lead identification and lead optimization processes can be slow for this class of drugs.
Complementary to traditional small molecule drugs is the class of therapeutics collectively referred to as biologics. This class includes proteins, enzymes and antibodies. Such large molecules (molecular weights range from ~10,000-50,000) are generally not suitable for oral administration and must be delivered by injection or infusion. This is inconvenient because these methods of use are generally not compatible with patient self-administration. Like small molecule drugs, biologics are useful as either agonists or antagonists of biological processes. However, unlike small molecules, biologics are only useful for extracellular targets. Additionally, biologics are generally highly selective and highly potent against target processes. Finally, like small molecules, lead identification and lead optimization are very slow processes.
For many years, the pharmaceutical industry focused on small molecule drugs. With the advent of the biotechnology industry, biologics have become increasingly important as evidenced by commercial successes from companies such as Genentech, Amgen and Biogen. Through the combined efforts of traditional drug discovery and the development of biologics, advances will continue to provide treatments for medical disorders providing improved qualities of life for all.