NEKTAR THERAPEUTICS 8-K

What Happened
Nektar Therapeutics announced on April 20, 2026, 52‑week topline results from the blinded 16‑week treatment extension of its Phase 2b REZOLVE‑AA study of rezpegaldesleukin, an investigational regulatory T‑cell biologic for severe‑to‑very‑severe alopecia areata (AA). REZOLVE‑AA enrolled 92 patients in a 36‑week induction (randomized 3:3:2 to two rezpegaldesleukin doses or placebo); 31 patients entered the blinded 16‑week extension (27 on rezpegaldesleukin — low dose 18 µg/kg n=14, high dose 24 µg/kg n=13 — and 4 on placebo). At week 52, active arms showed improved hair coverage versus placebo on several SALT (Severity of Alopecia Tool) endpoints and the company reported a favorable safety/tolerability profile through 52 weeks.

Key Details

• Study population and timing: Global Phase 2b REZOLVE‑AA; 92 patients enrolled; induction randomized 3:3:2; extension results reported April 20, 2026.
• Extension set: 31 patients continued to week 52 — low dose 18 µg/kg (n=14), high dose 24 µg/kg (n=13), placebo (n=4).
• Efficacy – SLAT thresholds at week 52 (overall population, with p‑values described as exploratory):
  • SALT ≤20 (≥80% scalp coverage): Low 25.8% (up from 14.8% at week 36), High 27.6% (from 15.6%), Placebo 6.7% — reported p = 0.049.
  • SALT ≤30 (≥70% scalp coverage): Low 30.2%, High 35.0%, Placebo 8.4% — reported p = 0.023.
  • SALT50 (≥50% improvement): Low 37.7%, High 38.8%, Placebo 13.6%.
  • New SALT ≤20 responses from week 36→52: 29% low dose, 31% high dose, 0% placebo.
• Safety and completion: 94% of patients completed 52 weeks; most treatment‑emergent adverse events were mild‑to‑moderate and resolved without intervention; most common events were mild‑to‑moderate injection site reactions that self‑resolved within ~5 days; no discontinuations during the extension due to TEAEs or ISRs.
• Analysis notes: Results use an mITT‑adapted population with imputation methods described; p‑values and some summaries are exploratory. Company plans to submit data for a medical conference in 2026.

Why It Matters
These topline 52‑week results give early evidence that twice‑monthly rezpegaldesleukin may increase hair regrowth over 52 weeks versus placebo in a difficult‑to‑treat AA population, with an acceptable safety profile in this study. For investors, the data are important milestones in the clinical development of rezpegaldesleukin (still investigational) and may affect the program’s path forward, regulatory discussions, and future data presentations. Note the company characterizes statistical summaries as exploratory and the therapy remains in clinical development with associated risks.