Nektar Therapeutics announced new data for rezpegaldesleukin (REZPEG), a first-in-class selective regulatory T-cell (Treg) therapy, in patients with atopic dermatitis (AD) at the 2023 European Academy of Dermatology and Venereology (EADV) Congress. These data were presented by Dr. Jonathan Silverberg, Professor of Dermatology at The George Washington University School of Medicine and Health Sciences and Director of Clinical Research and Contact Dermatitis in a late-breaking oral presentation. In the Phase 1b study, patients with moderate-to-severe AD that were treated with REZPEG showed dose-dependent improvements in Eczema Area and Severity Index (EASI), Validated Investigator Global Assessment (vIGA), Body Surface Area (BSA), and Itch Numeric Rating Scale (NRS) over 12 weeks of treatment compared to placebo, which were sustained post-treatment over an additional 36 weeks.

At the highest studied dose, the proportion of Daily Life Quality Index (DLQI) responders was 75% and the proportion of Patient Oriented Eczema Measure (POEM) responders was 65% at week 12. The proportion of responders were generally sustained after treatment ended through the 36-week follow-up. This durability highlights REZPEG's disease remittive potential.

REZPEG was well tolerated with no patients in the REZPEG groups experiencing severe, serious, or fatal adverse events, and no anti-REZPEG antibodies were detected. Pharmacodynamic data observed in the Phase 1b study corroborate the clinical efficacy signal observed in patients. Compared with placebo, there were sustained increases in absolute numbers of circulating total (FoxP3+CD25+) and CD25bright Tregs in the REZPEG treatment arms. The peak increase in CD25bright Treg number was 10-fold above baseline in the 24 µg/kg group.

Based on these data, the company is initiating two Phase 2 studies in atopic dermatitis and in alopecia areata. These trials are expected to initiate in October of this year and in early 2024, respectively. The trial design for the study in patients with moderate-to-severe atopic dermatitis was presented in an ePoster at EADV earlier this week.