Nektar Therapeutics Advances Rezpegaldesleukin Despite Mixed Phase 2b Results in Alopecia Areata
核心洞察
Nektar Therapeutics' rezpegaldesleukin showed promise in treating severe alopecia areata (搜索) but narrowly missed statistical significance in its Phase 2b Rezolve-AA trial.
The company attributed the statistical miss to four ineligible patients, claiming the drug met its primary endpoint when these participants were excluded from analysis.
Rezpegaldesleukin demonstrated a 28-30% reduction in hair loss scores compared to 11% for placebo, with a favorable safety profile and low dropout rates.
Nektar Therapeutics reported mixed results from its Phase 2b Rezolve-AA study of rezpegaldesleukin in alopecia areata (搜索), a condition where the immune system attacks hair follicles (搜索) affecting approximately 2% of both men and women. While the trial narrowly missed statistical significance, the company emphasized positive efficacy signals and plans to advance into Phase 3 testing next year.
Trial Results Show Promise Despite Statistical Miss
The Rezolve-AA study evaluated rezpegaldesleukin in patients with severe forms of alopecia areata (搜索), demonstrating hair growth promotion capabilities. In the full analysis, patients receiving rezpegaldesleukin achieved either a 28% or 30% reduction in SALT scores—a measurement of hair loss—compared with 11% for placebo recipients.
Nektar attributed the failure to reach statistical significance to the inclusion of four patients who should not have been eligible to participate. When these participants were excluded from the analysis, the treatment arms maintained approximately 30% reduction in SALT scores while the placebo group's response dropped to 5.7%. According to the company, this exclusion had no major effect on efficacy in the treatment arms, while the placebo response was cut almost in half due to one ineligible patient.
Safety Profile Supports Continued Development
The drug demonstrated a favorable safety profile consistent with previous studies. Almost all adverse events were considered mild or moderate and self-resolving, with only 1.4% of patients discontinuing treatment due to side effects. Notably, rezpegaldesleukin showed no increased risk of significant cardiovascular complications that have affected multiple JAK inhibitor drugs approved for the condition.
Market Opportunity in Underserved Population
Jefferies analyst Roger Song noted the potential for rezpegaldesleukin in his client note, stating "We believe there will be a market and great need for Rezpeg." He highlighted the dearth of available treatments and the drug's safety profile as offering "a strong commercial opportunity" for the autoimmune condition with an "urgent need" for more effective therapies.
Company Pivot Following Cancer Setback
This development represents part of Nektar's strategic pivot following a devastating cancer research disappointment. The company's previous partnership with Bristol Myers Squibb (搜索), which included a $1 billion upfront payment and $850 million equity investment in 2018, ended when their Phase 3 cancer combination trial failed in 2022. The fallout forced Nektar to lay off 70% of its workforce and refocus on rezpegaldesleukin, which had previously been partnered with Eli Lilly.
Earlier this year, a successful eczema (搜索) study helped ignite a comeback for Nektar shares, which had fallen below $10. However, investors appeared cautious about the alopecia results, with shares declining approximately 7% following the Tuesday announcement. The company's stock now trades under $50, well below the record highs reached in early 2018.
Nektar also faces an upcoming test with one-year maintenance results from rezpeg's Phase 2 study in moderate-to-severe eczema (搜索) expected this month, with shares down more than 40% since November ahead of these results.