Topical GX-03 Hits 92.6% EASI-50 at Week 4 in Phase 2 AD Interim

Turn Therapeutics announced interim findings from the first 50 subjects in its ongoing phase 2 randomized, double-blind, vehicle-controlled trial evaluating GX-03, an investigational extended-release topical formulation, in adults with moderate to severe atopic dermatitis (AD). The data, reviewed under an independent data monitoring committee (IDMC) framework, showed numerically higher response rates for GX-03 compared with vehicle across multiple EASI thresholds, with the most notable separation at earlier timepoints.¹

“What became increasingly apparent during the interim review was the speed with which responses emerged,” said Bradley Burnam, chief executive officer of Turn Therapeutics, in a news release. “The review identified opportunities to refine enrollment criteria and endpoint selection while providing valuable insight into where GX-03 activity appears most visible. The consistency of response across earlier efficacy measures suggests clinically meaningful improvement may emerge sooner than originally anticipated, which could have important implications for both future regulatory strategy and patient outcomes.”

RECENT AD NEWS

Responder Rates at Week 4 and Week 8

At 4 weeks, 92.6% of subjects in the GX-03 arm achieved EASI-50 — a 50% or greater reduction in eczema severity — compared with 65.2% in the vehicle arm. Deeper responder thresholds showed a more modest but persistent separation: EASI-90 rates at week 4 were 44.4% for GX-03 versus 30.4% for vehicle, widening slightly to 51.9% versus 34.8% by week 8. The week 8 trajectory suggests that reductions in inflammatory burden continued to deepen over the course of the treatment period in a subset of GX-03-treated subjects.

No treatment-related serious adverse events, tolerability concerns, or discontinuations were reported during the interim period.

What GX-03 Is — and What It Isn't

GX-03 is a topical, extended-release formulation designed to deliver sustained localized exposure to polyhexanide — an antiseptic compound with established use in wound care — at the skin surface. The mechanism differs substantively from currently approved systemic or topical immunomodulatory therapies for AD, including dupilumab, lebrikizumab, tralokinumab, or JAK inhibitors such as upadacitinib and abrocitinib.² Rather than targeting specific cytokine pathways upstream, GX-03 is positioned as acting within the skin microenvironment to modulate local inflammatory signaling, though the precise mechanism in AD has not been fully elucidated in published regulatory-grade data.

How the Interim Was Used

Rather than conducting a standard conditional power analysis on a single endpoint, the company elected to use the completed 50-subject cohort as an integrated stage 1 analysis to assess responder dynamics, endpoint sensitivity, and baseline enrollment factors. Company leadership noted that higher-than-anticipated vehicle response rates in certain subpopulations prompted refinement of enrollment criteria for the second stage of the trial, with increased attention to baseline EASI scores and body surface area involvement — both standard variables in AD trial design that affect overall response and signal detectability.

Context and Considerations

The vehicle response rates observed — particularly the 65.2% EASI-50 rate at 4 weeks — are elevated compared with placebo arms in many AD trials, which typically fall in the 30% to 45% range depending on baseline severity and study design. The company acknowledged this as a driver of its protocol refinements, and the adaptive approach is consistent with established frameworks in phase 2 trial optimization. Enrollment has continued throughout the interim review process and is described as nearing completion of the originally planned sample size.

Commenting on the findings, dermatology expert Stephen Bresnick, MD, who recently co-authored a peer-reviewed publication on GX-03's proposed mechanism, noted that earlier disease control has demonstrated impact on both disease burden and patient quality of life in inflammatory skin disease — and that a favorable safety profile alongside rapid responder activity supports continued development, if these results hold.

Turn Therapeutics plans to present detailed data at the Jefferies Global Healthcare Conference on June 4, 2026. The company also indicated it is preparing to request a meeting with the FDA to discuss regulatory strategy and potential development pathways for GX-03 following trial completion.

References

1. Turn Therapeutics reports interim analysis findings and adaptive optimization strategy from phase 2 GX-03 trial in moderate-to-severe atopic dermatitis. News release. Turn Therapeutics. Published June 1, 2026. Accessed June 1, 2026. https://www.businesswire.com/news/home/20260601276401/en/Turn-Therapeutics-Reports-Interim-Analysis-Findings-and-Adaptive-Optimization-Strategy-from-Phase-2-GX-03-Trial-in-Moderate-to-Severe-Atopic-Dermatitis
2. Cui L, Liu P, Wu K, Han X, Peng G. Targeting the JAK/STAT pathway in atopic dermatitis. Front Immunol. 2026;17:1757562. 2026. doi:10.3389/fimmu.2026.1757562