Nektar's Alopecia Breakthrough Could Reshape Hair Loss Treatment Market

Stock Price Alert: NKTR Surges on Phase 2b Trial Announcement

Nektar Therapeutics (NKTR) just delivered something the market has been waiting for—topline results from its groundbreaking REZOLVE-AA Phase 2b trial, and investors are already voting with their wallets. The stock exploded overnight, climbing to $58 (up 8.82%) from yesterday’s close of $53.30. Over the past year, NKTR has traded between $6.45 and $66.92, making today’s move particularly noteworthy for those tracking this biotech player.

What’s Actually Behind the Pump: Understanding Rezpegaldesleukin

Here’s the core innovation: Nektar is testing Rezpegaldesleukin (NKTR-358), a selective IL-2 conjugate that does something most current therapies can’t. Rather than just suppressing symptoms, it’s designed to expand FOXP3-positive regulatory T cells (Tregs)—essentially teaching the immune system to stop attacking hair follicles and restore tolerance. Think of it as resetting the immune system’s error rather than just managing the damage.

Alopecia areata isn’t your typical hair loss. It’s a chronic autoimmune condition that causes patchy or complete baldness, often triggering severe psychological distress and tanking quality of life. Current treatment options are frankly limited, which is why the FDA handed Rezpegaldesleukin Fast Track designation in July 2025 for severe-to-very-severe cases—a clear signal that regulators see real unmet medical need here. The 2b curls of this program extend beyond AA, too: the same mechanism is being tested in atopic dermatitis and type 1 diabetes, suggesting broader therapeutic potential.

The 36-Week Induction Period: What We’re Looking At

The REZOLVE-AA trial is the first randomized Phase 2b study of this kind in alopecia areata. Today’s announcement covers the topline findings from the 36-week induction treatment phase—a long enough window to show whether Rezpegaldesleukin can actually deliver durable remission rather than temporary relief. That’s the critical test: can this approach actually reset immune tolerance, or is it just another symptomatic treatment?

For Nektar, a positive read-out here could validate the entire IL-2 conjugate platform and potentially accelerate Rezpegaldesleukin’s path toward commercialization. For patients living with autoimmune hair loss, it might finally offer something that addresses the root cause rather than just cosmetic workarounds.