San Francisco, USA | March 28, 2026
Phase 2b Data Demonstrates Strong Clinical Efficacy
Nektar Therapeutics has announced compelling results from its Phase 2b REZOLVE-AD and REZOLVE-AA clinical trials, highlighting the therapeutic potential of rezpegaldesleukin, a novel regulatory T-cell (Treg) stimulator, in treating autoimmune and inflammatory diseases. Presented at the 2026 American Academy of Dermatology (AAD) Annual Meeting, the data revealed statistically significant improvements in Eczema Area and Severity Index (EASI) scores among patients with moderate-to-severe atopic dermatitis (AD).
Across a 16-week induction period, patients receiving rezpegaldesleukin showed consistent and meaningful reductions in disease severity compared to placebo, regardless of baseline severity or geographic region. Importantly, patients achieved key clinical endpoints such as EASI-75 and EASI-90 responses, indicating substantial skin clearance and symptom improvement, positioning the drug as a promising alternative to current biologics that often show reduced efficacy in severe cases.
Breakthrough Potential in Alopecia Areata Treatment
In addition to atopic dermatitis, rezpegaldesleukin demonstrated encouraging results in severe-to-very-severe alopecia areata (AA) patients. Data from the REZOLVE-AA study showed that high-dose treatment achieved a mean reduction of 28.2% in SALT (Severity of Alopecia Tool) scores, compared to 11.2% in the placebo group at 36 weeks. When adjusted for protocol compliance, the treatment arms achieved approximately 30% improvement versus 6% in placebo, reaching statistical significance (p<0.05).
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The therapy was also reported to be well tolerated with a favorable safety profile, reinforcing its potential as a first-in-class immunomodulatory therapy. Researchers emphasized that rezpegaldesleukin’s mechanism—expanding regulatory T cells—targets upstream immune dysfunction, offering a broader and potentially more durable therapeutic effect compared to traditional cytokine-blocking biologics.
Regulatory Momentum and Future Development Plans
Building on these positive findings, Nektar Therapeutics is preparing to initiate the Phase 3 ZENITH-AD program in the second quarter of 2026, marking a critical step toward potential regulatory approval. The drug has already received FDA Fast Track designation for both atopic dermatitis and alopecia areata, underscoring its potential to address significant unmet medical needs. Rezpegaldesleukin is designed as a self-administered injectable therapy, targeting the interleukin-2 receptor pathway to restore immune balance by enhancing Treg cell activity.
This innovative approach may redefine treatment paradigms across multiple T cell-driven inflammatory diseases, including future indications beyond dermatology. With a robust pipeline and growing clinical validation, Nektar continues to position itself at the forefront of immunology-focused biopharmaceutical innovation, aiming to deliver differentiated, disease-modifying therapies that go beyond symptom management.
Source: Nektar Therapeutics press release
