Data from Phase 2b REZOLVE-AD and REZOLVE-AA Studies of Rezpegaldesleukin Presented at 2026 American Academy of Dermatology Annual Meeting

Rezpegaldesleukin demonstrates statistically significant improvement in mean percent EASI improvement across both moderate and severe atopic dermatitis patients Rezpegaldesleukin proof-of-concept data in alopecia areata patients presented as a late-breaking research oral presentation SAN FRANCISCO, March 28, 2026 /PRNewswire/ — Nektar Therapeutics (Nasdaq: NKTR) today showcased data in two presentations at the 2026 American Academy of Dermatology (AAD) Annual Meeting taking place in Denver, CO. At AAD 2026, data from the global Phase 2b REZOLVE-AD study in 393 patients with moderate-to-severe atopic dermatitis were presented by Dr. Raj Chovatiya, Associate Professor at Rosalind Franklin University of Medicine and Science Chicago Medical School and Founder and Director of the Center for Medical Dermatology and Immunology Research, in an oral poster session entitled “Novel Regulatory T-cell enhancing Biologic Rezpegaldesleukin: Phase 2b Efficacy, Safety, and Baseline Severity–Dependent Treatment Response in Moderate-to-Severe Atopic Dermatitis” [link to presentation]. Patient randomization was stratified based on baseline disease severity measured by v

IGA-AD® (validated Investigator’s Global Assessment for Atopic Dermatitis) and geographic region. As presented at AAD, patients in the Phase 2b REZOLVE-AD study demonstrated consistent reduction in mean Eczema Area and Severity Index (EASI) scores over the 16-week induction period as compared to placebo regardless of baseline disease severity as measured by baseline v

IGA-AD® scores of 3 or 4. During the 16-week induction period, patients also achieved comparable EASI-75 (at least a 75% improvement in EASI score from baseline) and EASI-90 response (at least a 90% improvement in EASI score from baseline). These disease improvement metrics were also comparable by geographic region.

“The consistency of EASI responses with rezpegaldesleukin across baseline disease severity further differentiates it from the standard of care biologic treatment, which can have lower response rates in more severe patients as compared to moderate patients,” said Raj Chovatiya, MD, PhD, MSCI, FAAD.

“We believe its novel agonist mechanism to expand regulatory T cells, which act as master regulators upstream of the cytokine-specific blockade mechanisms of other biologics to address multiple pathways, allows a potentially more consistent improvement across a broader patient population.” Based upon results from the Phase 2b REZOLVE-AD study of rezpegaldesleukin, Nektar is planning to initiate the Phase 3 ZENITH-AD program of rezpegaldesleukin in moderate-to-severe atopic dermatitis patients in the second quarter of 2026. At AAD 2026, Dr. David Rosmarin presented a late-breaking research oral presentation highlighting previously-released data1 titled: “Novel Regulatory T-cell Enhancing Biologic Rezpegaldesleukin: Phase 2b Efficacy and Safety Results Following 36-Weeks of Therapy in Severe-to-Very-Severe Alopecia Areata” [link to presentation].

On the primary endpoint of mean Severity of Alopecia Tool (SALT) reduction at 36 weeks of treatment, high dose rezpegaldesleukin, 24 µg/kg every two weeks (q2w), demonstrated a mean reduction in the SALT score of 28.2% in the 24 µg/kg arm versus 11.2% in the placebo arm. Mean percent reduction in SALT scores at 36 weeks was 30% for both treatment arms versus 6% in the placebo arm, achieving statistical significance (p20 had the option to continue for an additional 16 weeks of treatment through 52 weeks in a blinded extension period. Primary and secondary endpoints were assessed at the end of the 36-week induction treatment period.

About Rezpegaldesleukin Autoimmune and inflammatory diseases cause the immune system to mistakenly attack and damage healthy cells in a person’s body. A failure of the body’s self-tolerance mechanisms enables the formation of the pathogenic T lymphocytes that conduct this attack. Rezpegaldesleukin is a potential first-in-class resolution therapeutic that may address this underlying immune system imbalance in people with many autoimmune and inflammatory conditions.

It targets the interleukin-2 receptor complex in the body to stimulate proliferation of immune-modulating cells known as regulatory T cells. By activating these cells, rezpegaldesleukin may act to bring the immune system back into balance.

In February 2025, the U.S. Food and Drug Administration (FDA) granted Fast Track designation for rezpegaldesleukin for the treatment of adult and pediatric patients 12 years of age and older with moderate-to-severe atopic dermatitis whose disease is not adequately controlled with topical prescription therapies or when those therapies are not advisable. In July 2025, the FDA granted Fast Track designation for rezpegaldesleukin for the treatment of severe alopecia areata (AA) in adults and pediatric patients 12 years of age and older who weigh at least 40 kg. Rezpegaldesleukin is being developed as a self-administered injection for a number of autoimmune and inflammatory diseases.

It is wholly owned by Nektar Therapeutics. About Nektar Therapeutics Nektar Therapeutics is a clinical-stage biotechnology company focused on developing treatments that address the underlying immunological dysfunction in autoimmune and chronic inflammatory diseases. Nektar’s lead product candidate, rezpegaldesleukin (REZPEG, or NKTR-358), is a novel, first-in-class regulatory T cell stimulator being evaluated in one Phase 2b clinical trial in atopic dermatitis, one Phase 2b clinical trial in alopecia areata, and one Phase 2 clinical trial in Type 1 diabetes mellitus.

Nektar’s pipeline also includes a preclinical bivalent tumor necrosis factor receptor type II (TNFR

2. antibody and bispecific programs, NKTR-0165 and NKTR-0166, and a modified hematopoietic colony stimulating factor (CSF) protein, NKTR-4
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4. Nektar is headquartered in San Francisco, California. For further information, visit www.nektar.com and follow us on LinkedIn.

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