The trial results were presented by researchers from the dermatology department at Stanford University School of Medicine at the International Investigative Dermatology 2018 meeting held in Orlando, Florida.
The oral presentation was titled, “Phase 2 trial of a neurokinin-1 receptor antagonist for the treatment of chronic itch in epidermolysis bullosa patients.”
Serlopitant is a small molecule that was engineered to specifically inhibit the neurokinin-1 receptor, or NK1-R, which is an important molecular mediator of sensory nerve signaling, including the urge to scratch and cough.
The drug was initially developed by Merck (known as MSD outside the U.S. and Canada) and licensed to Menlo Therapeutics in 2012. The therapy candidate has been tested in more than 1,300 patients, showing a good safety profile, and it was well-tolerated in treatment regimens up to one year.
The ongoing, investigator-sponsored Phase 2 trial (NCT02654483) was designed to evaluate the potential of serlopitant to reduce chronic pruritus (itch) in epidermolysis bullosa patients. A total of 14 patients, ages 13 and older, were randomly treated with serlopitant 5 mg daily or a placebo for 56 days (eight weeks).
The ability of the treatment to reduced chronic pruritus was determined by daily self-reported itch severity using a numeric rating scale (NRS) ranging from 0-10.
Because of the small number of patients enrolled in the exploratory trial, the researchers could not fully address the effectiveness and overall impact of the therapy. Still, serlopitant was found to be well-tolerated by the patients, with no new safety issues reported.
An analysis of the itch scores revealed that serlopitant-treated patients experienced small but significant improvements, with a reduction of 0.88 points in NRS scores at eight weeks of treatment compared to placebo. A similar reduction in dressing change-associated itch was also reported.
In addition, 43% of patients treated with the investigative therapy achieved at least a three-point reduction in NRS itch score compared to 14% in the placebo group.
“We were pleased to see a greater reduction in pruritus in the serlopitant arm than in the placebo arm,” Albert Chiou, MD and MBA, clinical assistant professor of dermatology at Stanford School of Medicine and the lead author of the study, said in a press release.
“This is an important finding in EB [epidermolysis bullosa], as these patients experience significant pruritus, which has proven very difficult to manage,” Chiou said.
The results suggest that serlopitant may hold therapeutic potential to manage itch in EB, and provide support for larger efficacy studies.
“The findings of this exploratory study in epidermolysis bullosa patients further support the potential of serlopitant as a therapy to reduce pruritus,” said Paul Kwon, MD, chief scientific officer of Menlo Therapeutics.