BRIEF—Study suggests potential for biologics in skin conditions

A study by UK and US scientists that will be published in the Journal of Investigative Dermatology this month has suggested that large molecular weight drugs could be used for difficult-to-treat dermatological diseases such as psoriasis.

The study, which was carried out by the UK’s University of Reading in collaboration with pharma major GlaxoSmithKline and the topical formulation specialists, MedPharm, challenges current theories on the permeation and penetration of biologic-type drugs.

Traditional thinking has previously suggested that drugs with a molecular weight of above 500 Daltons will not permeate across the skin and hence cannot be applied topically for the treatment of dermatological diseases.

The aptamer used in this recent research was a RNA-based 62 unit nucleotide with a molecular weight of 20,395 Daltons. The aptamer is an active target for the treatment of a range of skin diseases such as psoriasis and atopic dermatitis.

Using ex vivo human skin, the aptamer not only passed through the stratum corneum but could also be detected at therapeutic levels in the epidermal and dermal layers.

The research showed that the aptamer remained in its biologically active conformation and was capable of binding to endogenous IL-23, a key biomarker for important inflammation pathways.

With larger biological molecules such as peptides and nucleotides being increasingly identified as important drug targets, this research opens up the possibility that similar biologics could be applied to the skin and treat dermatological diseases with no current satisfactory treatment.