Aclaris Shares Some New Research Data on ATI-502 in Androgenetic Alopecia

Small Study of ATI-502 Shows Three Times the Benefits in Women than Men

Aclaris is a US pharmaceutical company that has an interest in determining if their JAK inhibitor technologies can help grow hair in various types of hair loss conditions. They have been studying the use of their JAK inhibitors in various hair loss conditions such as alopecia areata and andrognetic alopecia. Recent studies of the Aclaris topical JAK inhibitor was disappointing for those with alopecia areata. Interestingy, the companies 6 month data with the same drug for treating androgenetic alopecia has shown some positive results. Equally surprising as well was the finding that women seem to have repsonded to the treatment much better than men.

This data comes from a press release that the company has shared on their website.

Small Study of AT-502 Indicates Potential Benfits for Women’s Hair Loss

The Aclaris company is just getting going with its look at the use of JAK inhibitors in androgenetic alopecia. The interest in using the JAK inhibitors to treat androgenetic alopecia dates back to findings by Columbia University researcher Dr. Angela Christiano.

Although Dr. Christiano’s hypothesis has been that inhibiting JAK pathways could help the balding process by blocking inflammation that otherwise keeps hairs dormant, this has not always seemed to be the case so far. Patients with alopecia areata and androgenetic aloepcia who are treated with JAK inhibitors often grow back their hair from the alopecia areata component but don’t really grow back the androgenetic alopecia component. In other words, much of the information we have to date would seem to suggest that JAK inhibitors like tofacitinib and ruxolitinib don’t help the balding process. So, to consider treating androgenetic alopecia with a JAK inhibitor might seem like a bit of a stretch.

The Aclaris study shared in this press release was a very small study of AT 502 in about 23 participants. The study subjects applied the topical JAK inhibitor twice daily for 26 weeks. 14 men and 6 women with androgenetic aloepcia were able to complete the study in a manner that allowed hairs to be counted “before and after”. 22 participants were able to give their opinions on the treatment and also have have their study doctors evaluate the benefits.

What came out as interesting to me in this preliminary study was just how much better the topical drug was in helping women with androgenetic alopecia than men. In fact, it appears the topical JAK had three times the growth promoting benefits in women than men. It is important to keep in mind that the study is small and further evaluation will be needed. Nevertheless, in women using the AT 502 there was an increase in the number of thick hairs (so called non vellus target hairs) by 15.3 hairs per square cm in women and 5.6 hairs per sq cm in men. 82 % of study subjects felt that they actually had some kind of improvement with the drug. According to the study doctors, about 73 % of patients in the study improved with AT 502.


This is interesting preliminary data. It’s pretty clear now that inflammation has a role in androgenetic alopecia, ‘Microinflammation’ is now the buzz word in the field and we’re slowly coming to all realize that the inflammation hiding under the scalps in patients with androgenetic alopecia is probably not a good thing.

See previous article: Inflammation in AGA:

It’s intriguing that these JAK inhibitors would have so much better of an effect in women than men. The improvements in 15 hairs per sq cm is quite significant and we’ll need to wait to see if the women in the study can hold on to this improvement through the 1 year time point and whether this can be confirmed in bigger studies (there were only 6 women in this particular study!)

Whether getting rid of this scalp “microinflammation” is best done with a JAK inhibitor or best done with some other type of treatment will await further studies. For now, we’ll all await the 1 year update on results from Aclaris.

Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887

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