Topical isotretinoin shows early efficacy in congenital ichthyosis

A new topical isotretinoin formula was safe and efficacious in the treatment of congenital ichthyosis, according to a proof-of-concept study.

“Clinical characteristics of congenital ichthyosis (CI) include hyperkeratosis, scaling and erythroderma,” Amy S. Paller, MD, Walter J. Hamlin Professor and Chair of dermatology at Northwestern University Feinberg School of Medicine and pediatric dermatologist at the Ann and Robert H. Lurie Children’s Hospital of Chicago, and colleagues wrote in a research letter. “Management typically involves emollients and keratolytics. Patients with lamellar (LI) or X-linked recessive (XLRI) CI often have considerable hyperkeratosis and scaling for which systemic retinoids are effective but may cause dose-limiting adverse events (AEs).

The multicenter, double-blind, phase 2a study evaluated PAT-001 0.1% or 0.2% (Patagonia Pharmaceuticals), a novel topical isotretinoin ointment, in pediatric CI patients compared with vehicle.

Ten subjects were enrolled in the 0.1% group and nine in the 0.2% group, of which seven had XLRI, 10 had LI and two had ichthyosis vulgaris.

AEs were reported in 14 patients, with most being mild. AEs were “possibly” treatment related in 25% of patients, “probably” treatment related in 3.6% and “definitely” treatment related in 10.7%. Seven patients discontinued treatment.

An improvement of at least 1 grade in Investigator Global Assessment score was reported in 100% of those in the 0.1% group compared with 66.7% of the placebo group, while a 2 grade or greater improvement was reported in 66.7% and 33.3%, respectively.

In the 0.2% group, a 1 grade or greater IGA improvement was reported in 100% of treated individuals compared with 87.5% of the vehicle group, while a 2 grade or greater IGA improvement was reported in 50% of treated individuals compared with 62.5% of the vehicle group.

Scaling was improved to clear, almost clear or mild in 100% of both treatment groups and 55.6% and 87.5% of each vehicle group.

“The results indicate no concerning safety signals nor evidence of systemic isotretinoin/tretinoin exposure,” the authors wrote. “PAT-001 0.1% appeared to have a stronger efficacy signal vs. 0.2%.”