Light-Activated Drug Treats Psoriasis Without Side Effects

For the 3% of people worldwide living with psoriasis, finding effective treatment without scary side effects has been nearly impossible until now.

Researchers from Spain's Institute for Advanced Chemistry of Catalonia have created a revolutionary drug candidate called PhotoVDRM that stays inactive in the body until doctors shine specific wavelengths of light on affected skin. The treatment eliminated psoriasis-like inflammation in mice without triggering any dangerous side effects.

The breakthrough solves a decades-old medical puzzle. Activating the vitamin D receptor helps psoriasis, but traditional drugs that do this can cause life-threatening calcium imbalances, leading to serious problems like bone malformations. That risk has kept every attempted oral medication off the market despite years of pharmaceutical company efforts.

Dr. Xavier Rovira and his team took a completely different approach using photopharmacology. Their molecule sits harmlessly in the body until blue or UVB light activates it precisely where patients need relief. Think of it like a light switch you can flip on exactly where you want treatment, leaving the rest of your body untouched.

The timing matters enormously for patients. Current biologic treatments work well for severe cases but cost a fortune, putting them out of reach for many. Meanwhile, 30% of psoriasis patients still lack adequate affordable options. Topical creams offer limited help and require careful medical monitoring because the therapeutic window is so narrow.

In preclinical testing, PhotoVDRM delivered robust therapeutic effects without causing hypercalcemia, the calcium dysregulation that derailed previous vitamin D receptor treatments. The study was published in ACS Central Science and involved collaboration between Spanish institutions, Johns Hopkins University, Purdue University, and pharmaceutical company Eli Lilly.

Why This Inspires

This research represents more than just progress against one disease. The photopharmacology approach opens doors to treating pain, cancer, and Parkinson's disease with unprecedented precision. By controlling when and where drugs activate, doctors could offer powerful treatments with far fewer side effects.

The skin's accessibility to light makes it the perfect testing ground for this technology, and psoriasis patients who've waited years for better options stand to benefit first.

Scientists are already exploring how to apply this light-controlled strategy to other vitamin D receptor diseases, potentially transforming how we think about targeted therapy. For millions living with painful psoriasis lesions, especially in sensitive areas, a future with effective, affordable, side-effect-free treatment is finally coming into focus.