For decades, treating an illness meant relieving symptoms. Medicine has advanced and saved lives, but it has often worked by trial and error: a drug works for some, fails for others, and we rarely know exactly why. This model is starting to fall behind. Medicine is now entering a new phase, that of targeted drug treatments, guided by precise knowledge of the biological mechanisms of diseases.
In practice, this represents a profound change. Instead of just treating what the patient feels, we begin to treat the causes of the illness. This is the principle of precision medicine, which is no longer a futuristic promise, it is a clinical reality in several areas.
An emblematic example comes from neurology. Migraine, long treated as a recurring and almost trivialized headache, is now understood as a complex neurological disease. Advances in understanding the role of CGRP, a central mediator of seizures, have enabled the development of drugs such as galcanezumab, which specifically block this biological target. Therapeutic improvisation comes out; Enter a mechanism-based strategy.
Another rapidly evolving area is that of Alzheimer’s disease. For years, we limited ourselves to symptomatic treatments, with a modest impact on disease progression. With therapies like donanemab, which act directly on the accumulation of beta-amyloid in the brain, the focus is on the early phase of the disease. It is not a cure, nor a universal solution. The benefit depends on early diagnosis, confirmation by biomarkers and strict indication criteria. However, the concept is revolutionary: intervene before neurological damage is irreversible.
Cardiology is perhaps the area where precision medicine has already demonstrated the clearest population impact. In the treatment of cholesterol, injectable drugs such as alirocumab, evolocumab and inclisiran, which act on the PCSK9 pathway, provide deep and lasting reductions in LDL cholesterol, including in patients who do not respond adequately to statins.
High blood pressure, another major public health challenge, is also starting to be addressed in this way. New injectable treatments in development, such as zilebesiran, work to silence the renin-angiotensin system through RNA interference, promoting prolonged reduction in blood pressure with spaced applications.
Obesity is another clear example. For decades, this was treated as a failure of individual behavior. It is today recognized as a chronic, multifactorial and biologically regulated disease. Drugs such as semaglutide, tirzepatide and retatrutide act on specific hormone receptors in the gut-brain axis, regulating satiety, metabolism and energy expenditure.
Even very widespread pathologies, such as insomnia, fall into this new paradigm. Drugs such as lemborexant (Dayvigo) selectively modulate the orexin system, which regulates the sleep-wake cycle. Unlike traditional hypnotics, which induce non-specific sedation, these drugs act on a defined brain circuit.
There is also an often underestimated aspect of these advances: treatment compliance. Long-acting injectable medications reduce forgetting, early discontinuation and inconsistent use, which are central problems in the treatment of chronic diseases.
However, these advances bring inevitable challenges. Targeted drugs are more expensive, require sophisticated diagnostics and systems capable of evaluating their cost-effectiveness based on evidence. Without clear criteria, there is a risk of increasing inequalities. Precision medicine must therefore go hand in hand with the evaluation of health technologies, well-defined protocols and responsible public policies.
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