NKTR Stock Eyes Worst Day In Over 3 Years On Rezpeg Data: William Blair Still Sees A Durability Edge

• Between week 36 and week 52 of the mid-stage REZOLVE-AA alopecia study, 29% of patients on the lower dose and 31% on the higher dose newly reached a level of hair coverage that leaves 20% or less of the scalp bare.
• In the companion REZOLVE-AD study in moderate to severe atopic dermatitis, patients who switched to monthly or every-three-month injections largely held their gains in rash clearance and itch through week 52.
• William Blair analyst Andy Hsieh kept an Outperform rating, saying the update adds to evidence that rezpeg has a material durability advantage over current standard treatments.

Shares of Nektar Therapeutics (NKTR) fell sharply by 21% on Thursday even as the company reported that its experimental skin drug, rezpegaldesleukin, kept working after treatment stopped, though the new response rates were modest and drawn from small patient groups.

The stock is now on track for its worst day since February 2023, if the losses hold. Analysts at William Blair and Jefferies, however, kept their bullish ratings on the stock.

NKTR's Alopecia Data 

Rezpegaldesleukin, or rezpeg, is designed to stimulate regulatory T cells, a part of the immune system that can calm attacks on the body’s own tissue. In severe alopecia areata, that attack strips hair from the scalp.

Between week 36 and week 52 of the mid-stage REZOLVE-AA alopecia study, 29% of patients on the lower dose and 31% on the higher dose newly reached a level of hair coverage that leaves 20% or less of the scalp bare. Those groups numbered only 14 and 13 patients. The claim that benefit held after dosing stopped rests on eight patients. None of the patients given a placebo newly reached the study’s main measure of success over that same stretch.

Among patients who had already responded after a year of treatment, 75% still met the threshold four months after stopping the drug, and 63% still did at six months, the company said.

Deeper regrowth, covering at least 90% of the scalp, rose from 7% at week 52 to 19% six months off treatment. Investigator David Rosmarin said existing systemic therapies have not shown this degree of lasting benefit and further regrowth after treatment ends. Safety through 52 weeks was described as favorable and consistent with earlier reports.

Eczema Trial Also Shows Improvement

In the companion REZOLVE-AD study in moderate to severe atopic dermatitis, patients who switched to monthly or every-three-month injections largely held their gains in rash clearance and itch through week 52. The share reaching complete clearance rose several-fold on continued dosing.

Nektar has started a third late-stage eczema study in patients who already tried a biologic or a JAK inhibitor, and plans to open a roughly 850-patient late-stage alopecia trial, ZENITH-AA, in early 2027.

NKTR Analysts Disagree

William Blair analyst Andy Hsieh kept an 'Outperform' rating on the stock, saying the update adds to evidence that rezpeg has a material durability advantage over current standard treatments. The firm pointed to an atopic dermatitis data update expected in the first quarter of 2027 as the next major catalyst.

Jefferies analyst Roger Song, meanwhile, called Thursday's selloff "unwarranted." The firm continues to see alopecia areata as "an underappreciated and untapped disease space" for rezpegaldesleukin. Jefferies has a $150 price target on the stock and a ‘Buy’ rating.

LLY Overhang On NKTR Stock

A separate legal fight with Eli Lilly is still unresolved. The companies partnered in 2017 to develop rezpeg, but Lilly later bought a rival eczema drug and ended the deal. Nektar sued for about $1 billion; a jury in September awarded only $90 million plus interest, and Lilly plans to challenge the verdict, so the money is not yet in hand.

How Did NKTR Retail Traders React?

On Stocktwits, retail sentiment around NKTR stock rose from ‘neutral’ to ‘bullish’ over the past 24 hours, while message volume stayed ‘high.’

A Stocktwits user said the stock has been stuck for years, the recent win against Eli Lilly wasn't really a win, and the company has nothing new coming that would change that.

Another user, however, opined that Lilly might try to buy out Nektar.

NKTR stock has gained 12% year-to-date. 

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