VYNE Therapeutics Inc. announced that it has completed the Phase 1b portion of a Phase 1b/2a clinical trial evaluating FMX114 for the treatment of mild-to-moderate atopic dermatitis (AD) (Study VY2021-01). FMX114 is VYNE's proprietary investigational combination gel formulation of tofacitinib and fingolimod. The product is being developed to address both the source and cause of inflammation in AD.

FMX114 has the potential to be the first topical combination product for the treatment of AD as well as the first topical product in clinical development that utilizes the sphingosine 1-phosphate receptor modulation mode of action. The objective of the Phase 1b portion of the study was to evaluate the preliminary clinical safety, dermal tolerance and pharmacokinetics of FMX114 and vehicle gels when topically applied for up to 2 weeks to individual qualifying atopic dermatitis lesions. The study planned to enroll up to 6 subjects with mild to moderate atopic dermatitis in this Phase 1b safety portion.

However, based on the data obtained from the first two completing subjects, the Human Research Ethics Committee (HREC) in Australia overseeing the study agreed to reduce the enrollment number to 4 subjects with mild to moderate atopic dermatitis. At the study baseline visit, each subject had two AD lesions of comparable severity and extent based on the Atopic Dermatitis Severity Index (ADSI) scoring assessment and qualifying lesions were randomized to either FMX114 or vehicle gel treatment. Adverse events, clinical laboratory results and local dermal tolerance data was collected throughout subject participation in the study.

Pharmacokinetics of tofacitinib, fingolimod and fingolimod 1-phosphate were evaluated based on blood/plasma concentration data obtained from highly sensitive and validated bioanalytical methods. Both FMX114 and vehicle gel treatments were generally well-tolerated, and no serious adverse events were recorded during study conduct. Pharmacokinetics of tofacitinib, fingolimod and fingolimod 1-phosphate are summarized below: The mean plasma Cmax of tofacitinib calculated on treatment day 1 and day 14 were approximately 50-fold and 1500-fold lower, respectively, when compared to the equivalent data for the lowest commercially available adult oral dose of tofacitinib (XELJANZ 5mg BD).

The mean plasma Cmax of tofacitinib was determined to be 0.914 ng/ml and 0.0220 ng/ml on treatment day 1 and 14 respectively (assay Lower Limit of Quantification [LLOQ]: 0.01ng/ml). Systemic drug accumulation of tofacitinib was negligible over the dosing period, with an accumulation ratio calculation based on Cmax of 0.03. In samples obtained one week after the end of treatment, tofacitinib was not quantifiable (<0.01ng/ml).

The pharmacokinetics of fingolimod and active metabolite, fingolimod 1-phosphate could not be determined as all whole blood concentrations were below the assay LLOQ (0.08ng/ml for both analytes). The mean whole blood Cmax for fingolimod and fingolimod 1-phosphate for the adult oral dose of fingolimod (GILENYA 0.5mg QD) is 3.7ng/ml and 1.8ng/ml respectively at steady state.