Light-activated drugs against psoriasis

A study led by the Institute of Advanced Chemistry of Catalonia (IQAC-CSIC) has demonstrated the potential of a new generation of light activated drugs to treat psoriasisan ailment that affects millions of people and that, in many cases, still does not have fully satisfactory solutions. The research, published in the journal ASC Central Scienceshows that it is possible to activate a medicine only in the affected areathus avoiding side effects on the rest of the body.

Psoriasis is a chronic inflammatory skin disease that affects approximately 3% of the population. It causes visible lesions, itching and, in some cases, pain, and can have a significant impact on quality of life.

Although in recent years there have appeared new drugs -especially biological ones- capable of reducing inflammation, these treatments usually have a “very high” cost and are not indicated for mild cases. In addition, they require medical supervision due to their narrow safety margin. Currently, 30% of those affected still do not have treatments adequate and economically available.

The role of vitamin D

It has long been known that the vitamin D receptor (VDR) plays a beneficial role in psoriasis. Activating it helps control skin inflammation. The problem is that this receptor is also involved in calcium metabolism, so its widespread activation can cause serious side effectssuch as dangerous alterations in blood calcium levels.

For this reason, although attempts have been made develop oral medications aimed at this receiver, none have reached the market. Current options are typically topical creams with limited effectiveness and requiring medical monitoring.

Drugs that are activated by light

The progress presented now proposes an innovative solution. The IQAC-CSIC team, in collaboration with Idibell, the University of Barcelona, ​​centers in the United States and the pharmaceutical company Eli Lilly, has developed photocontrollable moleculesthat is, compounds that are only activated when they receive a certain wavelength of light.

The IQAC-CSIC researcher Xavier Rovira explained that the objective was to design molecules that could be activated only where treatment is needed. The developed molecule, called PhotoVDRMremains inactive in the dark and is activated when receiving blue or ultraviolet B light, both already used in dermatological therapies.

Tests carried out in animal models have been encouraging. By activating the drug with light in the affected area, a clear reduction in inflammationwithout the usual side effects associated with the vitamin D receptor appearing.

According to the researcher Amadeu Llebaríathe treatment achieved a “robust therapeutic effect without systemic hypercalcemia“, one of the main obstacles that had stopped this type of therapies until now.

Although this is still research in the preclinical phase, the results open a promising path. The possibility of activate a drug only where it is needed could change the way we treat not only psoriasis, but also other diseases related to the vitamin D receptor.

The researchers emphasize that this approach would allow Safer, more personalized treatments with fewer side effectssomething especially relevant for chronic diseases that require prolonged therapies.