Nektar Therapeutics (NASDAQ:NKTR), a biotechnology company developing medicines for the treatment of auto-immune disorders, today 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 start of this Phase 2b study is another significant milestone for Nektar as we advance REZPEG, a potentially transformative new mechanism for alopecia areata and other auto-immune disorders," said Mary Tagliaferri, M.D., Chief Medical Officer at Nektar Therapeutics. "Alopecia areata is a disease where a patient's own immune system attacks hair follicles and the resulting hair loss can be devastating for patients. Current treatments available have high relapse rates and carry potential safety challenges. As a result, there is a high unmet need for durable and well-tolerated treatment options that target the underlying dysfunction of the immune system in these patients. We believe there's an opportunity for REZPEG to emerge as a novel biologic mechanism for alopecia patients and we look forward to our topline data from this study expected in the first half of 2025."

Nektar's global, randomized, double-blind, placebo-controlled, dose-ranging Phase 2b study will investigate the efficacy and safety of REZPEG in 84 participants with severe to very severe alopecia areata over a 36-week induction treatment period. 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 percent 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 percent improvement in SALT at other assessed timepoints.