Nektar Therapeutics has presented data of its atopic dermatitis (AD) candidate rezpeg (rezpegaldesleukin), which sent the company’s stock flying.
In the RESOLVE-AD trial (NCT06136741), the mean improvement on Eczema Area and Severity Index (EASI) score was 61% in the 24µg/kg every two weeks cohort, 58% in the 18µg/kg every two weeks cohort, and 53% 24µg/kg every four weeks cohort. In the placebo cohort, this was achieved in 31% of patients.
The key secondary endpoint of EASI75 was achieved in 42% of patients in 24µg/kg every two weeks, 46% of patients in 18µg/kg every two weeks, and 34% of patients in 24µg/kg once-monthly cohort, compared to 17% in the placebo cohort.
Other key secondary endpoints, including EASI-90, Validated Investigator’s Global Assessment for AD (vIGA-AD) 0/1, Itch Numerical Rating Scale (NRS) and mean change in Body Surface Area (BSA) were also significant in the high dose cohort.
Professor Jonathan Silverberg of George Washington University School of Medicine and Health Sciences, said: "For the first time, we observe a deepening of clinical effect for patients with extended dosing of investigational therapy beyond 16 weeks, with a strengthening of absolute EASI reduction, along with higher EASI-75 and vIGA 0/1 response rates following 24 weeks of treatment.”
The company presented the data from the Phase IIb trial for the first time at the 2025 European Academy of Dermatology and Venereology (EADV) Congress in Paris, France.
This comes three months after the company announced the trial met its primary endpoint, which surged stocks by 156%, from a 23 June close of $9.54 to a 24 June close of $24.45. At the time, however, Nektar did not provide the data. Since then, the biotech’s share price has continued to notch up to $55.61 at market open on 18 September – a 483% increase compared to market close on the 23 June.
In the study, rezpeg, an IL-2 pathway agonist and regulatory T-cell (Treg) proliferator, was being investigated in 393 patients with moderate-to-severe AD, also known as eczema.
The therapy was previously being developed in partnership with pharma giant Eli Lilly. However, the companies later cut ties, with Nektar accusing Lilly of publishing “erroneous data” on the therapy from Phase Ib studies. A month after accusing Lilly of the error, Nektar published new data, which it stated showed a statistically meaningful change in all three clinical efficacy endpoints in an AD study.
In recent years, Sanofi and Regeneron’s Dupixent (dupilumab) has been one of the leading AD therapies, especially in patients who have not responded to corticosteroid therapy. Dupixent is also approved in several other indications, including asthma, chronic obstructive pulmonary disorder (COPD), and hives.
According to GlobalData analysis, Dupixent made $14.14bn in sales in 2024, with a 2030 sales estimate of $25.9bn. If approved, GlobalData predicts rezpeg will make $222m in 2031.
GlobalData is the parent company of Clinical Trials Arena.
