REZOLVE-AD Phase 2b Study of Rezpegaldesleukin Meets Primary and Key Secondary Endpoints in Patients with Moderate-to-Severe Atopic Dermatitis Achieved statistical significance on primary endpoint at week 16 for mean per

Study of Rezpegaldesleukin Meets Primary and Key Secondary Endpoints in Patients with Moderate-to-Severe Atopic Dermatitis

Achieved statistical

significance on primary endpoint at week 16 for mean percent change in EASI score from baseline for all rezpegaldesleukin arms versus

Achieved statistical

significance for key secondary endpoints at week 16 of disease reduction, including EASI-75, EASI-90, Itch NRS, vIGA-AD and BSA

of EASI reduction and magnitude of itch improvement show potential differentiation of this novel regulatory

T-cell mechanism as a first

and best-in-class immune-modulator

Robust dose-dependent

reduction of inflammatory biomarkers in atopic dermatitis including TARC/CCL17, periostin, MDC/CCL22, and IL-19

Safety profile consistent with previously

Data expected in Q1 2026 from continued

treatment of patients with atopic dermatitis in long-term maintenance part of REZOLVE-AD study

Top-line Phase 2b data for rezpegaldesleukin

in alopecia areata expected in Q4 2025

Conference call and webcast with management

and atopic dermatitis experts today at 8:15 am ET / 5:15 am PT

SAN FRANCISCO, June 24, 2025 /PRNewswire/ -- Nektar Therapeutics

(Nasdaq: NKTR), a clinical-stage biotechnology company focused on development of novel immunology therapies, today announced statistically

significant data from the 16-week induction period of the ongoing Phase 2b REZOLVE-AD study of investigational rezpegaldesleukin, an IL-pathway

agonist and regulatory T-cell (Treg) proliferator.

The global Phase 2b study is being conducted in 393 patients with moderate-to-severe

atopic dermatitis. Patients were randomized (3:3:3:2) to receive subcutaneous treatment with three doses of rezpegaldesleukin: a high

dose of 24 g/kg every two weeks (q2w), a middle dose of 18 g/kg every two weeks (q2w), and a low dose of 24 g/kg

every four weeks (q4w), or placebo q2w. The primary endpoint and secondary endpoints were assessed at week 16. Following a 16-week induction

period, rezpegaldesleukin-treated patients who achieved EASI percent score reductions of >50 were re-randomized (1:1) to continue

at the same dose level on a q4w or q12w regimen through week 52 in a blinded maintenance period. Placebo patients with EASI percent score

reductions of >50 percent continue to receive placebo q4w.

Rezpegaldesleukin Achieved Primary and Key Secondary Efficacy Endpoints

The trial met its primary endpoint of the mean improvement in Eczema

Area and Severity Score (EASI) from baseline at week 16 for all three dose arms of rezpegaldesleukin versus placebo (p<0.001).

All three dose arms also achieved statistical significance at week

16 for the key secondary endpoints of EASI-75 (percent of patients who achieve 75% reduction in EASI from baseline), EASI-50 (percent

of patients who achieve 50% reduction in EASI from baseline) and BSA (mean percent improvement in Body Surface Area score from baseline).

The q2w arms of rezpegaldesleukin (high and middle doses) achieved statistical

significance at week 16 for the key secondary endpoints of vIGA-AD 0/1 (percent of patients achieving a score of 0 or 1 on the validated

Investigator's Global Assessment for Atopic Dermatitis with 2-point reduction from baseline) and Itch NRS (percent of

patients with baseline 4 who experienced a 4-point reduction in the Itch Numerical Rating Score from baseline).

In addition, at week 16, the high dose of 24 g/kg q2w achieved

statistical significance on EASI-90 (percent of patients who achieve 90% reduction in EASI from baseline).

When evaluating EASI-75 and EASI-90 by disease severity using baseline

vIGA-AD score, similar responses were observed in severe patients (baseline vIGA-AD of 4) as in moderate patients (baseline vIGA-AD of

"These data from REZOLVE-AD show a fast onset of both EASI response

and itch relief within the first few doses of rezpegaldesleukin treatment, which are important metrics for physicians as they assess treatment

options in atopic dermatitis," Prof. Jonathan Silverberg, MD, PhD, MPH Professor of Dermatology at George Washington University

School of Medicine and Health Sciences. "This shows the advantage of a broad-based Treg mechanism over other immune-modulation approaches

in development to treat the disease. Additionally, we don't see any increased risk of incidence of conjunctivitis, oral herpes,

or oral ulcers with this mechanism of action as we do with other mechanisms."

"These REZOLVE-AD results present a new therapeutic hypothesis

for treatment of dermatological diseases and the investigators are looking forward to rezpegaldesleukin advancing in development in atopic

dermatitis," said Prof. David Rosmarin M.D., Chair, Department of Dermatology and Associate Professor of Dermatology, Indiana University

School of Medicine. "With the establishment of this efficacy profile in the dermatological setting of atopic dermatitis, we are

also eager to see the upcoming results from the ongoing REZOLVE-AA study in patients with severe to very-severe alopecia areata."

Across all three dose arms, translational blood biomarker data demonstrate

robust on-target and dose-dependent pharmacological activity with an increase in total Tregs of up to 6-fold in the high dose arm. Sustained

Treg cell proliferation was observed at week 16 as compared to baseline and was correlated with reduction of key T helper 2 (Th2) inflammatory

markers: IL-19, TARC/CCL17, periostin, and MDC/CCL22.

"We believe that the REZOLVE-AD study results clearly demonstrate

that Nektar has established a new biology and harnessed the promise of Tregs as an important potential therapeutic modality to treat inflammatory

skin disorders and other autoimmune conditions," said Howard W. Robin, President and CEO of Nektar Therapeutics. "These

compelling efficacy findings are further boosted by the translational data that show, for the first time, that rezpegaldesleukin also

reduced key markers of Th2 inflammation in atopic dermatitis. With this validation in atopic dermatitis, we also look forward to reporting

results in the fourth quarter of this year for rezpegaldesleukin in alopecia areata."

Nektar plans to submit these REZOLVE-AD 16-week induction results for

presentation at a medical conference later in 2025.

Safety Profile Consistent with Previously Reported Results

The safety profile for the 16-week induction period for rezpegaldesleukin

was consistent with previously reported results. The most common treatment-emergent adverse events (TEAEs) were local injection site reactions

(ISRs), observed in 69.7% of all rezpegaldesleukin-treated patients, with the largest proportion of these being mild or moderate (99.6%).

ISRs were self-resolving and <1% of patients discontinued because of an ISR. Across all rezpegaldesleukin doses administered in the

study over the 16-week induction period, 55.9% had no reports of ISRs, 30.1% had mild reports, 13.8% had moderate reports, and only 0.2%

were severe. Other TEAEs more commonly observed (>5%) in the study treatment arms (n=320) versus placebo (n=73) include eosinophilia

(7.8% vs. 2.7%), pyrexia (6.3% vs 2.7%), headache (6.3% vs. 4.1%) and arthralgia (5.0% vs 1.4%).

In the pooled rezpegaldesleukin arms, TEAEs, excluding ISRs, were reported

in 60.3% of patients and in 57.5% of placebo-treated patients.

There was no increased risk of conjunctivitis, oral ulcers, or infections,

including oral herpes, in the rezpegaldesleukin arms.

Safety over 16-Week Induction Period

Webcast to Discuss Results of Phase 2b REZOLVE-AD Trial

Nektar management will

host a conference call and live webcast with Drs. Silverberg and Rosmarin today, June 24, 2025, to review the results at 8:15 a.m. Eastern

Time / 5:15 a.m. Pacific Time.

The accompanying slides and the webcast of

the conference call can be accessed through a link on Nektar's website on the investor relations page. To access the webcast directly,

please click on the following link to register to join the Zoom webcast: https://lifescievents.com/event/sro974rcsq260kbgiw59/

The web broadcast of the conference call will

be available for replay through July 25, 2025.

About REZOLVE-AD Phase

The REZOLVE-AD trial was initiated in October 2023 and enrolled

patients across approximately 110 sites globally with: 68% enrolled and treated in Europe, including Poland, Bulgaria, Germany,

Czech Republic, Spain, Croatia and Hungary; 16% enrolled and treated in the United States; 11% enrolled and treated

in Canada; and 5% enrolled and treated in Australia. Patient randomization was stratified based on baseline disease severity

measured by vIGA-AD and geographic region. Key enrollment criteria in the study included a minimum EASI score of 16.0, a minimum

Body Surface Area (BSA) of 10% and a minimum vIGA-AD of 3.

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