What is Drug Discovery?
Drug discovery refers to the process of finding and optimizing specific molecules for testing in humans. It precedes human testing via the drug development process. Discovery can be broken up into several steps including target identification and validation, hit generation, and lead generation and optimization.
Target identification is the process by which a target is identified for a potential drug to work on. There are many steps that can be taken to further validate this target as something that will modify the disease or symptoms- these tests are part of the target validation process.
Once a target is identified, potential drug agents (“hits”) can be identified and tested through various screening procedures to test their ability to bind the identified target as well as to quantify how they may interact with other potential parts of the body (especially as they may lead to side effects). Through screening of what is often thousands of potential compounds, a lead compound may be identified as one that is particularly promising.
The lead itself will then be tested in greater rigor and potentially optimized to add or improve on favorable characteristics. Once a lead is optimized, it is ready to go into pre-clinical studies including animal testing.
The drug discovery process often involves trial-and-error and a lot of back-and-forth. Sometimes things may not flow completely as described above, depending on new things that are learned about a molecule as it is studied. The discovery process, as with drug development has to often find a balance between derisking (reducing the chances for failure in clinical trials) a potential agent and moving it forward for preclinical and clinical testing so that it can eventually be available to patients and be marketed by the company- much of these decisions come down to an art rather than just science.
Derek Lowe is a discovery scientist who often blogs about new methods, data, and industry affairs.