Mechanisms of disease

4. Medicines interaction with target

If a target for the treatment of a given disease has been identified through comprehensive experiments in the discovery phase, the developer of the medicine can still not be sure that the medicine being developed will show the desired interaction with the target when used in patients. In fact, when used on patients the most important thing for the developer to see is effects against the disease (i.e. showing ‘efficacy’ - that the medicine works). The medicine can have the expected effect on the target, but the symptoms of disease may remain unchanged. This may be due to other mechanisms in the body that override the effect of the medicine on the target.  They take over for the pathway that has been affected by the medicine.