Turn Therapeutics (TTRX) investor relations material

Trial enrichment strategies and regulatory impact

• Enrichment in clinical trials uses patient characteristics to increase the likelihood of detecting a drug effect, reducing variability and de-risking outcomes.

• Prognostic and predictive enrichment approaches are used, with predictive enrichment common in oncology and increasingly in other diseases.

• Trial design and enrichment directly influence drug labeling, affecting physician prescribing, insurance coverage, and commercial market size.

• Most recent FDA-approved cancer drugs used predictive biomarkers for enrichment, a trend expanding to other therapeutic areas.

Measurement and gaps in atopic dermatitis trials

• Disease severity in atopic dermatitis is measured by vIGA (lesion severity) and EASI (extent of disease), both critical for patient assessment.

• Current systemic therapies require an EASI ≥16, excluding patients with severe but localized disease from access to these drugs.

• This measurement gap leaves patients with high severity but low extent (low EASI) with unmet medical needs, as they are ineligible for systemic treatments.

• Enriching trials to include both localized and extensive moderate-to-severe cases could address this gap and better reflect clinical reality.

Adaptive trial design and interim findings

• The trial uses a two-stage adaptive design, with the first 50 patients unblinded for interim analysis to refine endpoints and enrichment criteria.

• Self-reported pruritus (itch) score emerged as a key enrichment factor, with higher scores correlating with greater treatment effect separation.

• Statistical significance was achieved in week 4 vIGA and EASI-75 endpoints, with dramatic separation at higher pruritus thresholds.

• Stage 2 of the trial uses a baseline pruritus score ≥7 and stratifies patients by EASI to ensure balanced representation across disease extent.

• Interim data showed compelling efficacy, with significant improvements in vIGA and EASI-100 at week 8, supporting the trial's enrichment strategy.