One piece of this enormous drug development puzzle is the mode of action of the drug. If that is identified and understood, much information can be gained, from both a cellular and systemic perspective.
If we know what pathways are triggered, we also know what type of components are either activated, inhibited, or synthesized. By tracking these effects, we can evaluate and understand the clinical effects of a biopharmaceutical, the drug’s mechanism of action. Hence, it is important to know THAT it works, but also HOW it elicits its therapeutic effect.
A functional assay that is reflective of the mechanism of action (MoA) can be a great tool to assess biopharmaceuticals. The growing consensus is that the selection of analytical method should be driven by a product's intended physiological/therapeutical mechanism of action.
In cases where the MoA is simply binding to a target, a surrogate method, such as a protein binding or competitive binding assay, may be sufficient but in cases where a more stepwise reaction is happening for the drug to induce its effect, an assay that more closely reflects and mimics these steps is needed to properly study the biological context and physiological reactions. This is referred to as MoA Reflective Assays.
The selection of an appropriate MoA Reflective Assay to determine and assess these complex biopharmaceuticals has its challenges. Not only do you need to mimic an often complex and sometimes not completely understood mechanism of action, but you also need to develop, perform, transfer and maintain these costly bioassays.
Unlike other analytical techniques, bioassays are almost always unique for each therapeutic compound.
On the other hand, a well-designed bioassay will accurately capture the biological activity of a drug candidate and give you more “value for your sample” or value for your measurement since it allows you to follow a series of events instead of just a momentary snapshot. Imagine being able to monitor the falling domino bricks in a row instead of just seeing the moment when the first “push” is being made.
That is why functional, MoA reflective, bioassays are key in understanding the aspects of a drug compound during the drug development process and post-launch release and holds great value in making correct and informed decisions on that drug program.