Turn Therapeutics Finalizes Phase 2 Study Design for GX-03 Following Positive Interim Analysis in Atopic Dermatitis
Turn Therapeutics, Inc., a clinical-stage biotechnology company focused on developing targeted, non-systemic therapies for inflammatory skin disorders, has announced the completion of a comprehensive interim analysis of its ongoing adaptive Phase 2 clinical trial evaluating GX-03 for the treatment of atopic dermatitis. The analysis has resulted in the finalization of the Stage 2 study design, incorporating several data-driven refinements intended to strengthen the trial and enhance its ability to support future regulatory development.
The extensive review confirmed encouraging efficacy signals across a broader range of disease severity than originally anticipated, prompting the company to expand the Phase 2 study to include patients representing the full spectrum of baseline disease severity as measured by the Eczema Area and Severity Index (EASI). The updated study design is expected to provide a more comprehensive assessment of GX-03’s therapeutic potential while maintaining rigorous statistical standards and preserving the adaptive nature of the clinical program.
According to Turn Therapeutics, enrollment has continued without interruption throughout the interim review, allowing the company to maintain development timelines while incorporating new scientific insights into the final stage of the trial.
Advancing a Novel Topical Therapy for Atopic Dermatitis
Atopic dermatitis, commonly referred to as eczema, is one of the most prevalent chronic inflammatory skin diseases worldwide. The condition is characterized by persistent itching, inflamed skin, recurrent flare-ups, and significant impairment in quality of life.
Although numerous treatment options are available, many patients continue to experience inadequate disease control or concerns related to long-term use of topical corticosteroids and systemic immunomodulatory therapies.
Turn Therapeutics is developing GX-03 as a targeted, non-systemic topical therapy designed to address inflammation directly within the skin while minimizing systemic exposure. The company’s approach aims to provide an effective treatment option with a favorable safety profile suitable for patients across a broad spectrum of disease severity.
The ongoing adaptive Phase 2 trial represents an important step in determining the clinical efficacy and safety of GX-03 while optimizing study parameters for future regulatory submissions.
Adaptive Trial Design Enables Data-Driven Improvements
Unlike traditional clinical trials that follow a fixed protocol from beginning to end, adaptive studies are specifically designed to incorporate new information as clinical data emerge.
Turn Therapeutics’ Phase 2 program includes two stages, allowing investigators to analyze early results before finalizing the design of the second stage.
Following an earlier preliminary interim review involving the first 50 completed participants, the company initiated a more comprehensive multi-week analysis under the supervision of the Independent Data Monitoring Committee.
The review was led by Bruce Stouch, Ph.D., the study’s lead biostatistician, together with Dr. Stephen Hahn, Executive Clinical and Regulatory Lead at Turn Therapeutics and former Commissioner of the U.S. Food and Drug Administration.
The evaluation examined treatment-response patterns, patient characteristics, baseline disease severity, predefined efficacy endpoints, exploratory outcomes, and statistical methodologies.
According to the company, the objective was to maximize the scientific value of data collected during Stage 1 while optimizing the final Stage 2 design that will serve as the principal efficacy phase supporting future regulatory development.
Interim Analysis Reveals Broader Treatment Activity
One of the most significant findings from the comprehensive review was the observation that GX-03 demonstrated clinically meaningful efficacy across a wider range of atopic dermatitis severity than originally expected.
Initially, the study focused primarily on patients with greater inflammatory burden.
However, analysis revealed encouraging treatment responses among participants with baseline EASI scores ranging from 1.1 to 7.0, a population generally classified as having mild-to-moderate atopic dermatitis.
Although all Stage 1 participants presented with moderate-to-severe lesions according to the Investigator’s Global Assessment (IGA), overall disease burden varied considerably, allowing investigators to evaluate treatment performance across multiple severity levels.
The observed responses within patients exhibiting lower EASI scores suggested that GX-03 may have potential utility in a broader patient population than originally anticipated.
These findings ultimately supported expanding enrollment criteria during Stage 2.
Week 4 Emerges as Key Assessment Timepoint
The interim review also identified Week 4 as the earliest and clearest point at which GX-03 demonstrated meaningful separation from the vehicle control.
Based on these observations, Week 4 efficacy assessments have now been incorporated into the final Stage 2 protocol as key study endpoints.
The findings suggest GX-03 may produce relatively rapid clinical improvements, an important characteristic for topical therapies intended to manage inflammatory skin conditions.
Rapid symptom improvement can be particularly meaningful for patients experiencing persistent itching, skin irritation, and recurrent disease flare-ups.
Pruritus Severity May Predict Treatment Response
Investigators identified another potentially important observation during the interim analysis.
Baseline pruritus severity—or the intensity of itching experienced before treatment—appeared to correlate with treatment response.
This suggests that baseline itch severity may serve as a useful biomarker for identifying patients most likely to benefit from GX-03 therapy.
The company plans to prospectively incorporate this finding into the Stage 2 study population, further refining patient selection while enhancing scientific understanding of treatment response patterns.
If confirmed in later analyses, this biomarker could contribute to more individualized treatment approaches during future clinical development.
Expansion Across the Full EASI Spectrum
Based on encouraging efficacy observed across multiple disease severity categories, Turn Therapeutics has expanded the ongoing Phase 2 trial to evaluate patients across the complete baseline EASI spectrum.
Rather than focusing primarily on patients with higher inflammatory burden, the final Stage 2 study will include individuals within three baseline severity categories:
- EASI 1.1-7.0
- EASI 7.1-15.9
- EASI 16 or higher
This broader enrollment strategy is intended to determine whether GX-03 provides consistent clinical benefit across patients with mild, moderate, and more severe forms of atopic dermatitis.
The expansion also creates opportunities to evaluate the therapy in patient populations commonly treated with topical medications in routine clinical practice.
Encouraging Results in Mild-to-Moderate Disease
Among patients with baseline EASI scores between 1.1 and 7.0, GX-03 demonstrated clinically meaningful improvements compared with vehicle treatment.
Investigators observed favorable outcomes in Week 4 validated Investigator’s Global Assessment for Atopic Dermatitis (vIGA-AD) Success.
Additionally, patients receiving GX-03 achieved complete disease clearance at both Week 4 and Week 8 more frequently than those treated with vehicle.
These findings broaden the potential clinical relevance of GX-03 by suggesting therapeutic activity extends beyond patients with extensive inflammatory disease.
Final Stage 2 Study Design
The finalized Stage 2 protocol will enroll approximately 120 to 135 patients.
Participants will be prospectively stratified according to baseline EASI severity before undergoing 1:1 randomization within each severity category.
Importantly, every enrolled participant will contribute to a unified efficacy analysis designed to evaluate GX-03 consistently across the expanded patient population.
The adaptive design allows investigators to assess treatment performance across varying disease severities while preserving statistical rigor.
Multiple Efficacy Endpoints Strengthen Evaluation
Rather than relying upon a single primary endpoint, the finalized Stage 2 study will prospectively evaluate four predefined efficacy endpoints representing increasingly stringent levels of clinical improvement.
These include:
- Week 4 vIGA-AD Success
- Week 4 EASI-75
- Week 8 EASI-90
- Week 8 EASI-100
To analyze these outcomes, investigators will employ the FDA-recognized Hochberg multiple testing procedure.
This statistical methodology controls Type I error while permitting evaluation of multiple clinically meaningful endpoints within a single trial.
According to Turn Therapeutics, this approach strengthens the scientific robustness of the study while increasing opportunities to demonstrate clinically relevant treatment benefits.
Enrollment Continues Without Delay
An important feature of the adaptive trial design has been the ability to continue patient enrollment throughout the comprehensive interim review.
Rather than pausing recruitment, investigators maintained uninterrupted enrollment while preserving study blinding.
Patients enrolled during the review period remain blinded and will be fully incorporated into the final Stage 2 efficacy analyses.
This approach minimizes development delays while maximizing the value of all collected clinical data.
Turn Therapeutics expects enrollment under the finalized protocol to continue throughout 2026.
Favorable Safety Profile Maintained
Safety findings remain encouraging.
Consistent with previous updates, investigators reported no treatment-related serious adverse events in either treatment group.
No treatment-related tolerability concerns have emerged during the ongoing study.
Likewise, no participants have discontinued treatment because of treatment-related adverse events.
Overall, GX-03 continues to demonstrate a favorable safety and tolerability profile, supporting its continued evaluation as a topical therapy for atopic dermatitis.
Maintaining strong safety alongside encouraging efficacy will remain a critical objective as the program advances through later-stage development.
Turn Therapeutics anticipates completing enrollment in the Phase 2 study during the fourth quarter of 2026.
The company also stated that it remains sufficiently funded to support completion of the trial and planned corporate operations through the third quarter of 2027.
The completion of the comprehensive interim analysis represents a significant milestone in the clinical development of GX-03. By expanding the study population, refining efficacy endpoints, incorporating potential predictive biomarkers, and strengthening the statistical design, Turn Therapeutics aims to generate more robust evidence supporting the therapy’s potential across a wider spectrum of atopic dermatitis patients.
If the encouraging trends observed during the interim review are confirmed in the completed Stage 2 trial, GX-03 could emerge as a promising non-systemic topical treatment capable of addressing an important unmet need for patients with mild, moderate, and severe atopic dermatitis while supporting future regulatory submissions and broader clinical use.
About Turn Therapeutics
Turn Therapeutics is a clinical-stage biotechnology company focused on developing targeted, localized therapies for inflammatory and infectious skin diseases. GX-03 is Turn Therapeutics’ lead investigational topical candidate being developed as a targeted, non-systemic treatment for atopic dermatitis, designed to deliver biologic-level efficacy without the trade-offs of injectable administration or systemic immunosuppression.