Topical Isotretinoin (TMB-001) Treatment for 12 Weeks Did Not Result in Clinically Relevant Laboratory Abnormalities in Participants with Congenital Ichthyosis in the Phase 2b CONTROL Study.

INTRODUCTION: Treatment with oral retinoids can be effective in patients with congenital ichthyosis (CI) but may be associated with clinically significant laboratory changes. In this Phase 2b CONTROL study analysis, we characterize the effects of TMB-001, a novel topical isotretinoin formulation, on laboratory values in participants with X-linked recessive (XLRI) and autosomal recessive lamellar (ARCI-LI) ichthyosis at 12 weeks. METHODS: A randomized, double-blind, vehicle-controlled, Phase 2b study was conducted with participants ≥ 9 years of age with confirmed XLRI and ARCI-LI. Participants were randomized 1:1:1 and stratified by CI subtype to receive TMB-001 0.05%:TMB-001 0.1%:vehicle twice daily for 12 weeks. Laboratory analyses were performed at screening and Week 12. RESULTS: Among 33 enrolled participants (TMB-001 0.05% n = 11, TMB-001 0.1% n = 10, and vehicle n = 12), 52% had ARCI-LI and 48% had XLRI. At 12 weeks, there were single reports of anemia, neutropenia, leukopenia, lymphocytosis, and leukocytosis after vehicle treatment; neutropenia was reported in one participant receiving TMB-001 0.1%. There were single reports of abnormal biochemistry values-liver enzymes, creatinine, urea nitrogen, hyperkalemia, and hyperproteinemia-across treatment cohorts. Non-fasting hyperglycemia was observed in three participants receiving TMB-001 0.1% and one participant receiving vehicle. Urinalysis abnormalities reported in > 1 participant included urobilinogen (TMB-001 0.1% n = 2, vehicle n = 2), protein (TMB-001 0.1% n = 3, vehicle n = 2), and leukocyte esterase (TMB-001 0.1% n = 2). Laboratory parameter changes were asymptomatic and did not require study discontinuation or drug withdrawal. CONCLUSION: There were no clinically significant laboratory changes in participants receiving TMB-001 isotretinoin ointment through 12 weeks of treatment, which differs from reported results for systemic isotretinoin. TRIAL REGISTRATION: NCT04154293.

Characteristics and outcomes for participants with congenital ichthyosis who responded to treatment with the topical isotretinoin formulation TMB-001: results from the Phase IIb 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. OBJECTIVES: This analysis from the randomized Phase IIb CONTROL study investigated the characteristics of participants who responded to treatment with TMB-001, a novel topical isotretinoin ointment formulation. METHODS: Participants ≥ 9 years of age with genetically confirmed CI and ≥ 2 (out of 4) Visual Index for Ichthyosis Severity (VIIS) assessment areas with ≥ 3 scaling score were randomized 1 : 1 : 1 to TMB-001 0.05%, TMB-001 0.1% or vehicle, twice daily for 12 weeks. Efficacy endpoints included the proportion of participants with ≥ 50% reduction in VIIS-scaling (VIIS-50) compared with baseline and ≥ 2-grade reduction in Investigator's Global Assessment (IGA)-scaling score compared with 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: Among the 33 participants (11 randomized to TMB-001 0.05%, 10 to TMB-001 0.1% and 12 to vehicle), median age was 29 years (range 9-80), 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.

Phase IIb randomized CONTROL study demonstrates a novel topical isotretinoin formulation, TMB-001, is safe and effective in participants with either recessive X-linked or autosomal recessive lamellar congenital ichthyosis.

BACKGROUND: In two severe congenital ichthyosis subtypes, autosomal recessive lamellar ichthyosis (ARCI-LI) and X-linked recessive ichthyosis (XLRI), cutaneous manifestations include widespread scaling. Approved topical treatment options are limited to emollients and keratolytics. AIM: This analysis from the randomized phase IIb CONTROL study assessed whether the efficacy and safety of TMB-001, a novel topical isotretinoin ointment formulation, differed between ARCI-LI and XLRI subtypes. METHODS: Participants ≥ 9 years with genetically confirmed XLRI or ARCI-LI and ≥ 2 (of 4) Visual Index for Ichthyosis Severity (VIIS) assessment areas with ≥ 3 scaling score were randomized 1 : 1 : 1 to TMB-001 0.05%/TMB-001 0.1%/vehicle, twice daily for 12 weeks. The proportion of participants with ≥ 50% reduction vs. baseline in VIIS scaling (VIIS 50; primary endpoint) and ≥ 2-grade reduction in Investigator's Global Assessment (IGA)-scaling score vs. baseline (key secondary endpoint) were evaluated. Adverse events (AEs) were monitored. RESULTS: Among enrolled participants (TMB-001 0.05%, n = 11; 0.1%, n = 10; and vehicle, n = 12), 52% had ARCI-LI and 48% XLRI subtypes. Mean age was 33.6 and 35.4 years for participants with ARCI-LI and XLRI, respectively. Overall, 33%, 50% and 17% of participants with ARCI-LI and 100%, 33% and 75% of participants with XLRI achieved VIIS 50 in the TMB-001 0.05%, TMB-001 0.1% and vehicle groups, respectively (nominal P = 0.24 for 0.05% vs. vehicle, intent-to-treat population). Improvement of ≥ 2-grade IGA score was observed in 33%, 50% and 0% of participants with ARCI-LI and 83%, 33% and 25% of participants with XLRI in the TMB-001 0.05%, TMB-001 0.1% and vehicle groups, respectively (nominal P = 0.03 for 0.05% vs. vehicle, intention-to-treat population). Most AEs were application-site reactions. CONCLUSION: Regardless of congenital ichthyosis subtype, TMB-001 demonstrated greater proportions of participants achieving VIIS 50 and ≥ 2-grade IGA improvement vs. vehicle.