Nektar Therapeutics Launches Phase 3 Trials for Rezpegaldesleukin

The ZENITH AD program comprises three large-scale, randomized, double-blind trials, each enrolling 510 patients. ZENITH AD-1 and ZENITH AD-2 focus on individuals who have not previously received systemic biologics or JAK inhibitors, while a third study, ZENITH AD-3, will include treatment-experienced patients. Following successful End-of-Phase 2 discussions with the FDA and guidance from the EMA, the company expects to report initial topline data in mid-2028, with a BLA submission targeted for 2029.

Rezpegaldesleukin functions as a first-in-class regulatory T-cell agonist, addressing the underlying immune system imbalances that drive chronic inflammatory conditions. Chief Medical Officer Mary A. Tagliaferri noted that the therapy offers a differentiated approach by acting upstream of common inflammatory pathways. Beyond atopic dermatitis, Nektar is preparing for a registrational Phase 3 trial in alopecia areata in early 2027 and is evaluating the drug's efficacy in Type 1 diabetes. The current atopic dermatitis program will involve 1,530 patients across North America, Europe, and the Asia-Pacific region, testing monthly and quarterly maintenance dosing regimens.