Nektar Therapeutics announced the initiation of its Phase 2b clinical trial evaluating rezpegaldesleukin in patients with severe to very severe alopecia areata. RezpegaldesleUKin (REZPEG) is a novel agonistic T regulatory cell biologic that is designed to both dampen the inflammatory response and simultaneously restore immune balance by directly expanding functional T reg cells and engaging multiple immunoregulatory pathways. The induction treatment period will compare two different dosing regimens of REZPEG against placebo.

Participants will be followed for an additional 24 weeks after the end of the treatment period to evaluate durability. Initial results from the study are anticipated in the first half of 2025. The primary efficacy endpoint will evaluate mean% improvement in the Severity of Alopecia Tool (SALT) at week 36.

Secondary endpoints include proportion of participants with greater than or equal to 50% reduction in SALT at week 36 and other assessed timepoints and mean% improvement in SALT at other assessed timepoints. By activating these cells, REZPEG may act to bring the immune system back into balance. REZPEG is being developed as a self-administered injection for a number of autoimmune and inflammatory diseases.

In addition to this clinical trial in patients with severe to verysevere alopecia areata, REZPEG is also being evaluated in a Phase 2b study in the treatment of adult patients with moderate-to-severe atopic dermatitis (REZOLVE-AD; NCT06136741).