Pharmacology and drug development · BEGINNER LESSON
Therapeutic target
A therapeutic target is a specific molecule or biological process that a treatment is meant to interact with or change in order to produce a desired biological response. In drug research, the term often refers to a molecular target such as a protein or RNA, but it can also mean a target mechanism at a higher biological level.
What it is and what is measured
A therapeutic target is the object or process a treatment is aimed at. In many drug papers, it means a specific molecular target such as a protein or RNA molecule that a drug interacts with to start a biological response. In some fields, especially experimental therapeutics, the target can also mean a target mechanism: a measurable process, such as a behavioral, cognitive, or neurobiological change, that is proposed to lead to a clinical outcome. What is measured is therefore either the binding or interaction with the molecule, or the change in the process itself and whether that change links to the outcome.
[1] Mechanism of Action and Target Identification - PMC - NIH [2] Experimental Therapeutics: Opportunities and Challenges ... [3] Therapeutic Target Identification and Drug Discovery Driven ...
How it works
For small-molecule drugs, the target may be an enzyme, a cell-surface receptor, or a membrane transporter. The drug can inhibit, activate, or block the target, and that interaction can alter signaling or other cellular processes that eventually change tissue behavior or symptoms. In target-mechanism work, researchers also ask whether changing the mechanism truly mediates the clinical effect, meaning the mechanism helps explain why the intervention works.
[1] Mechanism of Action and Target Identification - PMC - NIH [2] Experimental Therapeutics: Opportunities and Challenges ... [3] Therapeutic Target Identification and Drug Discovery Driven ...
How targets are found and validated
Researchers may use target-based screening, which starts with a known or suspected molecular target, or phenotypic screening, which looks for a useful effect first and only later asks what the target is. Chemical proteomics is one approach that helps identify small-molecule targets. A target is stronger when evidence shows it is linked to the disease or symptom, can be measured reliably, can be changed by the intervention, and can plausibly explain the outcome.
[1] Mechanism of Action and Target Identification - PMC - NIH [3] Therapeutic Target Identification and Drug Discovery Driven ...
Limitations and cautions
Knowing the target is not always required for drug approval, and some approved drugs still have no known target or clear mechanism of action. A proposed target can also turn out to be a false target if early validation was incomplete. Another limitation is off-target effects, where a drug also interacts with other proteins and this can affect both safety and efficacy. In some disease areas, especially psychiatric disorders, one mechanism may affect only some symptoms, not every symptom in a diagnosis.
[1] Mechanism of Action and Target Identification - PMC - NIH [2] Experimental Therapeutics: Opportunities and Challenges ... [3] Therapeutic Target Identification and Drug Discovery Driven ...
SEE THE IDEA
From target to outcome
Choose a molecule or a measurable mechanism that is linked to the disease or symptom.
The treatment binds, blocks, activates, or otherwise changes the target.
A cell, signaling pathway, or behavior changes in response.
The change is linked to a symptom, function, or disease endpoint.
The treatment acts on the target, the target changes a mechanism, and the mechanism contributes to the outcome.
A therapeutic target connects a treatment to a measurable biological or behavioral change, but the link must be supported by evidence.
TRY IT YOURSELF
Test your understanding
Choose an answer, then check the explanation.
PUT IT TOGETHER
Match each concept to its meaning
Drag a label onto its description, or select a label and then select a description. This also works with a keyboard.
4 pairs to match
Sources and further reading
This general lesson was generated from public source material. It explains a concept; it does not interpret a private paper or provide medical advice.