The U.S. Food and Drug Administration (FDA) has granted Fast Track designation for Nektar Therapeutics’ rezpegaldesleukin for the treatment of severe-to-very-severe alopecia areata (AA) in adults and pediatric patients aged 12 and older who weigh at least 40 kilograms.
Rezpegaldesleukin is an investigational biologic therapy that targets the interleukin(IL)-2 receptor complex in the body to stimulate proliferation of inhibitory immune cells known as regulatory T cells (Tregs). Results from multiple clinical trials showed that rezpegaldesleukin safely and dose-dependently increased Tregs.
“We are pleased that rezpegaldesleukin has been granted Fast Track designation for the treatment of alopecia areata, adding to its Fast Track designation in atopic dermatitis,” says Jonathan Zalevsky, PhD, Senior Vice President and Chief Research & Development Officer at Nektar, in a news release. “We remain on track to announce topline data in December from our ongoing REZOLVE-AA Phase 2b study for rezpegaldesleukin in alopecia areata, and we look forward to the opportunity to collaborate quickly with the agency on a potential registrational program following the completion of Phase 2.”
The FDA’s Fast Track process ensures that new treatments reach patients as quickly as possible. The designation is granted to investigational therapies that treat serious conditions and have the potential to address an unmet medical need. A drug candidate that receives Fast Track designation is eligible for more frequent meetings and written interactions with the FDA to discuss the drug candidate’s development plan as well as possible eligibility for rolling review and priority review.
This trial was initiated in March 2024. Patients were enrolled across approximately 30 sites globally, with 62% enrolled in Poland, 24% enrolled in Canada, and 14% enrolled in the United States.
The REZOLVE-AA study enrolled approximately 90 patients with severe-to-very-severe alopecia areata who have not previously been treated with a janus kinase (JAK) inhibitor or other biologic. Patients were randomized across two different dose regimens of rezpegaldesleukin or placebo. The primary efficacy endpoint will evaluate the mean percent change in the Severity of Alopecia Tool (SALT) score at the end of the 36-week induction period.
Secondary endpoints include the proportion of participants with greater than or equal to 50% reduction in SALT score at week 36 and other assessed timepoints, the mean percent improvement in SALT score at other assessed timepoints, and the proportion of patients achieving SALT-20 (an absolute SALT score of less than or equal to 20). The Company expects to share these results in December 2025.
Enrollment criteria in the study included a diagnosis of severe-to-very-severe alopecia areata (≥ 50% scalp involvement) as measured using the SALT score at both screening and randomization. Patients who experienced an unstable course of alopecia areata over the last 6 months per investigator assessment were excluded from the study. Patients with diffuse alopecia and other forms of alopecia were also excluded. Patient randomization was stratified based on baseline disease severity as measured by the SALT score.
