Dutch biotech company Micreos Human Health has initiated a Phase I/IIa clinical trial to evaluate the safety and efficacy of XZ.700 in patients with mild to moderate atopic dermatitis.

The first trial participants have been enrolled.

The randomised, double-blind, placebo-controlled, parallel treated dose-ranging study is the first to test a pharmaceutical endolysin for topical use in humans, according to the company.

Endolysins are enzymes obtained from naturally occurring phages. They can degrade the bacterial cell wall and rapidly kill the target bacteria, irrespective of antibiotic resistance, while maintaining the skin microbiome.

XZ.700 is designed to selectively target Staphylococcus aureus (S aureus), a bacterium involved in the development and aggravation of atopic dermatitis and an independent cause of itch, irritation and infection.

Initial targeted indications of the drug candidate are atopic dermatitis, diabetic wound infections by S aureus, including methicillin-resistant Staphylococcus aureus (MRSA), and cutaneous T-cell lymphoma.

Micreos Human Health scientific advisor and dermatologist Peter Lio said: “The targeted removal of one particular bacterial species, S aureus, from the skin microbiome while preserving the beneficial ones is a fundamental new way to treat atopic dermatitis.”

The Phase I/IIa trial will be carried out in 48 patients with atopic dermatitis in The Netherlands. In addition to safety and efficacy, XZ.700 will be tested for its pharmacodynamics.

During the 14-day treatment period, the trial population will be given a topical cream containing XZ.700 at three different concentrations or placebo.

Micreos plans to wrap up the study and publish the results by end of next year.

Micreos Human Health CEO Mark Offerhaus said: “Thanks to the targeted nature of endolysins and the fact that emergence of resistance is not expected, we can use them as effective precision tools in the post-antibiotic era, in both chronic and critical situations.

“With the start of the XZ.700 trial we take the technology to the next level and create tomorrow’s history.”

Micreos portfolio also includes a structurally similar endolysin, SA.100, used in over the counter (OTC) products for inflammatory skin ailments, such as acne and rosacea. SA.100 is used in the Gladskin range, which has been commercialised since 2013.