Data Readout

Nektar's rezpeg faces Q4 off-treatment readout after alopecia data already showed responses

REZOLVE-AA's 24-week off-treatment data will test whether rezpegaldesleukin's alopecia areata responses persist after dosing stops, following positive on-treatment results already disclosed.

By AppliedXLJuly 14, 2026Trial NCT06340360

Executive Summary

Nektar has already disclosed a positive on-treatment signal for rezpegaldesleukin in severe alopecia areata, so the coming readout shifts the question from whether the drug works to whether the effect holds once dosing stops.
The drug's IL-2 Receptor agonist mechanism has no other Phase 2 program in alopecia areata, so there is no same-class Phase 2 result to benchmark this trial against.
The trial's primary completion date moved and enrollment fluctuated during setup, but the study is now closed to enrollment and holding at its target size, a completed operational trajectory rather than a live risk to the readout.
Alopecia areata's approved and late-stage field runs on JAK inhibition, giving rezpegaldesleukin's Treg-expanding mechanism a distinct hypothesis to test against an established drug class rather than a mechanism-matched rival.

The catalyst

Nektar Therapeutics expects to report topline data from the 24-week off-treatment observation period of the Phase 2b REZOLVE-AA study in severe-to-very-severe alopecia areata in the fourth quarter of 2026, guided in both its March and May 2026 disclosures. The trial, registered as NCT06340360, enrolled 94 adults with severe to very severe disease, measured by scalp hair loss on the Severity of Alopecia Tool (SALT), and randomized them across two rezpegaldesleukin dose arms and a placebo comparator. The registered primary endpoint is percent change from baseline in SALT score at Week 36, with secondary endpoints tracking the proportion of patients reaching absolute SALT scores of 10, 20, 30 or 50 and those achieving 50%, 75% or 90% relative improvement. Nektar+1

Probability of Success

Endpoint Met1%

Completes67%

Clinical Significance28%

Regulatory46%

What's already known

The pending off-treatment readout follows an on-treatment result Nektar has already disclosed. The company reported topline data in April 2026 from the trial's 16-week blinded treatment extension, describing a deepening of responses in severe-to-very-severe alopecia areata at the 52-week timepoint, though it released no numeric efficacy or safety figures in that release. Nektar's CEO Howard W. Robin said the 2025 Phase 2 data across atopic dermatitis and alopecia areata were "successful and transformative" and that the 52-week treatment data "provide hope that complete clearance of disease could be possible" with maintenance dosing. The Q4 2026 disclosure will show what happens to that response once treatment stops, the question the primary Week 36 endpoint alone cannot answer. Nektar

Trial operations

The study's registry history shows an enrollment target that moved from 110 to 84 in August 2024, then rose in two steps to settle at 94 by April 2025, alongside two revisions to the primary completion date, from August 2025 to November 2025 and then to November 26, 2025. The trial has been Active, not recruiting since February 2025, and enrollment has held flat at its 94-patient target since April 2025, the kind of settled enrollment picture that follows a study once accrual closes. The FDA granted rezpegaldesleukin Fast Track designation for severe-to-very-severe alopecia areata in adults and adolescents in July 2025, a designation that speaks to unmet need in this population rather than to trial outcome. NCT06340360

The competitive frame

No other industry trial pairs an IL-2 Receptor agonist with alopecia areata at Phase 2 or later, making rezpegaldesleukin the only asset testing this mechanism in the indication at this stage. The active late-stage alopecia areata field is built instead on JAK inhibition: AbbVie's upadacitinib, Eli Lilly's baricitinib, Pfizer's ritlecitinib and Sun Pharma's deuruxolitinib are each in Phase 3, with completions running from 2028 into 2030. Those programs share an indication with rezpegaldesleukin but none share its target or mechanism class, so the readout tests a Treg-expansion hypothesis against an established JAK-inhibitor standard of care rather than against a mechanism-matched peer.

The durability bar

With no validated non-JAK mechanism yet established in severe alopecia areata and no same-target Phase 2 precedent to benchmark against, the informative result is whether SALT-score improvement seen during dosing is retained, rather than reverting toward baseline, across the 24 weeks after rezpegaldesleukin is withdrawn. Nektar's rezpegaldesleukin program is also running a Phase 3 trial in atopic dermatitis using the same IL-2 Receptor agonist mechanism, so a durable off-treatment result in alopecia areata would extend readthrough to how the same Treg-expansion approach is expected to perform once patients move off maintenance dosing in that program too. NCT06340360+1

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