Characteristics and outcomes for participants with congenital ichthyosis who responded to treatment with the topical isotretinoin formulation TMB-001: Results from the Phase 2b CONTROL study.

BACKGROUND: Emollients and keratolytics are frequently used to manage symptoms of congenital ichthyosis (CI). Systemic retinoid treatment is complicated by teratogenicity and dose-limiting adverse effects.

AIM: This analysis from the randomised Phase 2b CONTROL study investigated the characteristics of participants who responded to treatment with TMB-001, a novel topical isotretinoin ointment formulation.

METHODS: Participants ≥9 years with genetically confirmed CI and ≥2 (out of 4) Visual Index for Ichthyosis Severity (VIIS) assessment areas with ≥3 scaling score were randomised 1:1:1 to TMB-001 0.05%:TMB-001 0.1%:vehicle twice daily for 12 weeks. Efficacy end points included the proportion of participants with ≥50% reduction vs baseline in VIIS-scaling (VIIS-50) and ≥2-grade reduction in Investigator Global Assessment (IGA)-scaling score vs baseline. Changes in body surface area (BSA) involvement, Dermatology Life Quality Index (DLQI) scores, and Itch-Numeric Rating Scale (I-NRS) scores were assessed.

RESULTS: Of the 33 participants (TMB-001 0.05% [n = 11], 0.1% [n = 10], and vehicle [n = 12]), median age was 29 years, and most were male (64%) and White (79%). Baseline demographics were generally similar among participants who did or did not achieve TMB-001 treatment success. Participants who had lower mean BSA involvement and higher DLQI and I-NRS scores at baseline were more likely to achieve VIIS-50. Similarly, higher baseline DLQI and I-NRS scores were associated with IGA response; BSA involvement was similar for IGA responders vs nonresponders.

CONCLUSIONS: Higher DLQI and I-NRS scores at baseline were associated with participants achieving treatment success by VIIS-50 and IGA response. Lower BSA involvement was associated with VIIS-50 success.