Nektar’s new eczema drug meets trial goals, but the difference from idols is unclear

Nektar treatment has reached the skin clearance target in an interim clinical trial of atopic dermatitis. Although these preliminary results are new approaches to the therapy that validate new approaches to drive the immune response of the disease, analysts noted that the market for atopic dermatitis drugs is crowded and it is not clear whether Nektar’s drug can stand out, especially for a large number of Sanofi products, whose approval includes atopic dermatitis.

The placebo-controlled phase 2B test evaluated three doses of the Nektar drug Rezpegaldesleukin (Rezpeg for short), of which 393 patients with moderate to severe atopic dermatitis were also called eczema. The main goal is to measure the change in scores based on the scale used to assess disease severity – the higher the score, the more severe the disease is. San Francisco-based Nektar said Tuesday that all three of its doses showed statistically significant score changes at 16 weeks. The high-dose group showed the biggest improvement, with the group’s score dropping by 30%.

REZPEG is a biological drug designed to target interleukin-2 (IL-2) receptor complex, which stimulates the proliferation of regulatory T cells (Tregs), an immune cell that inhibits excessive immune responses. This approach is designed to restore balance to the immune system. This is different from other biological drugs that work by blocking certain proteins or pathways associated with inflammation. Sanofi and Regeneron Pharmaceuticals’ Dupixent is an antibody designed to block the IL-13 and IL-4 pathways. The sensational product is currently the top biology of atopic dermatitis.

The comparison across trials has limitations, but it is difficult to avoid them when the target of the candidate drug is to compete with the top product under indication. Phase 2B of Dupixent results in atopic dermatitis showing a 50% reduction in the placebo-adjusted average score in the 16-week period. William Blair analyst Andy Hsieh pointed out in a study that from a regulatory perspective, getting 75% or higher improvement from a baseline measure is a key measure. Both the mid- and high-dose scores of Rezpeg far outweigh the dupixent marker of this measure.

From a tolerability perspective, REZPEG may also be at a disadvantage. Although Nektar reported that Nektar’s drugs are safe and tolerant compared to the results of the Dupixent study, the most common adverse event was the injection site response, but REZPEG released these reactions in the test at a higher rate.

“We believe that there is a relatively high incidence of injection site responses observed to REZPEG without significantly different potency data,” Hsieh said.

Preliminary REZPEG results announced on Tuesday came from the 16-week enrollment of its Phase 2B test. Patients continued during the 36-week maintenance section of the study; data for this section is expected to be in the first quarter of 2026. Nektar believes the drug has the potential to solve other immune diseases. Areata’s Phase 2B test is expected to release preliminary data in the fourth quarter of this year.

REZPEG’s performance made Nektar’s stock price soar, opening at $20 per share on Tuesday, greater than Monday’s closing price. Hsieh acknowledged Nektar’s stock price rose, but he described it as a “valuation normalization event” rather than attributed value to differentiated assets. He noted that Nektar shares traded around the company’s current cash level, which reported about $227 million at the end of the first quarter of this year. Hsieh added that he is looking for more data updates to further demonstrate the therapeutic effect of Rezpeg, which could improve the competitiveness of the assets.

Rezpeg is Nektar’s most advanced program. The drug is entirely owned by biotechnology, but not always. In 2017, Eli Lilly paid $150 million in advance to start a partnership on Rezpeg. Eli Lilly terminated the alliance in 2023 after disappointing clinical trial results. Months later, Nektar sued Lily for breach of contract, accusing her former partner of misestimating data in atopic dermatitis and psoriasis studies in support of the atopic dermatitis medication it obtained from Dermira. Last September, this IL-13 blocking antibody, brand EBGlyss, gained FDA recognition in atopic dermatitis. Meanwhile, Nektal’s lawsuit against Eli Lilly continues.

Photo: Getty Images