Results from a Phase 2 open-label clinical trial of ATI-502 (AGA-201), an investigational topical Janus Kinase (JAK) 1/3 inhibitor are promising for patients with androgenetic alopecia (AGA). Aclaris Therapeutics announced the findings and says 12-month data should be available by year’s end.

The trial evaluated ATI-502 in women and men with AGA. Subjects aged 18-50 years (n=31) applied ATI-502 to their scalp twice daily for 26 weeks. Twenty-three subjects completed 6 months of treatment. Twenty subjects (14 male, 6 female) had evaluable hair counts, and twenty-two (15 male and 7 female) recorded investigator global assessment (IGA) and subject self-assessment (SSA) scores.  

The primary endpoint was the mean change from baseline in non-vellus target area hair count (TAHC) at week 26.  The overall change was an increase of 8.6 hairs/cm^2. TAHC increase was 15.3 hairs/cm^2 in female subjects and 5.6 hairs/cm^2 in male subjects.

The secondary endpoints included an IGA and SSA. Subjects who experienced increased hair growth were given a score of +1 or better on the IGA and SSA (+1 = slightly increased hair growth, +2 = moderately increased hair growth, and +3 = greatly increased hair growth). Based on these endpoints, investigators rated 73% of subjects (16/22) as experiencing increased hair growth, and 82% of subjects (18/22) rated themselves as experiencing increased hair growth. ATI-502 was well-tolerated.

There were no treatment-related serious adverse events. There was one unrelated serious adverse event of breast cancer reported, and one patient withdrew for treatment-related alopecia in week one.

“The combination of the TAHC data, the investigator and subject assessments, and our own internal review of the formal photography, suggest topical JAK inhibition is a viable approach to treating AGA,” says Dr. Neal Walker, President and Chief Executive Officer of Aclaris. “This finding demonstrates that inhibiting a non-hormonal and inflammatory-mediated pathway may be an option for the treatment of AGA.”

“There has been no novel drug approved for the treatment of AGA for decades. These data are encouraging and suggest ATI-502 may be a potential treatment for patients with AGA – especially women,” says Dr. Janet Roberts of Northwest Dermatology Institute, Portland, OR, a Principal Investigator in the clinical trial.

Aclaris says that recent formulation work allows the company to achieve significantly higher topical concentrations of ATI-502 and hopes to initiate a double-blind, randomized, controlled Phase 2 dose-ranging clinical trial with higher concentrations of ATI-502 in the first half of 2020. That trial may be female-focused.