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JAK Inhibitor Increases Hair Growth in Women and Men with Pattern Hair Loss

The latest news in hair restoration research comes from Aclaris Therapeutics, Inc., which has released results of its Phase 2 clinical trial of ATI-502. It is a topical Janus Kinase 1/3 inhibitor, also known as a JAK inhibitor, applied directly to the scalp. The clinical trial explored the effectiveness and safety of ATI-502 for patients with male pattern hair loss and female pattern hair loss.

The results of the 6-month study of a 0.46 percent solution of ATI-502 found that it did lead to new hair growth, especially for women. Men in the study showed very positive results in the first few months, but the longer they used ATI-502 the treatment ceased being as effective. While there were no serious adverse side effects, it is notable that ATI-502 apparently caused hair loss in at least one subject, while two others experienced inflammation and itchiness. We’ll get into the specifics of the study results in a moment.

For the past several years, we have reported on the possibility JAK inhibitors could slow hair loss and regrow hair in some people experiencing male and female pattern baldness. Aclaris came into the picture in 2016 when it acquired Vixen Pharmaceuticals and all intellectual property covering the use of JAK inhibitors to fight hair loss that had been developed at Columbia University.

At the time, Dr. Neal Walker, President and Chief Executive Officer of Aclaris said:

“The acquisition of the Vixen intellectual property and the licensed JAKPharm and Key Organics compounds solidifies Aclaris’ presence in the JAK inhibitor space and allows us to broaden our focus in hair loss to include androgenetic alopecia. With this expansion of our pipeline, we continue to pursue our core strategy of developing and commercializing self-pay aesthetic and medical dermatology products for which there is a significant unmet need.”

In the months that followed, Aclaris stock climbed as high as $32. Today it is hovering right around $5.

To be clear, we at Arocha Hair Restoration don’t evaluate hair loss treatments based on stock price, but it’s important to consider all factors when examining the information an organization is releasing. Sometimes, desperation can be a powerful incentive, even when intentions are good.

Mixed Results

Aclaris portrayed the findings from the clinical trial to be “positive results,” but women have more to celebrate than men do. On average, the six women who participated in the hair count evaluation saw a steady and sustained increase of total area hair count over the 26 weeks, exceeding an increase of 15 hairs per cubic centimeter. Investigators examined the treatment area of seven women and determined that four of the seven (57 percent) showed increased hair growth.

For men in the study, the findings were more complicated. The hair count evaluation showed men very quickly showed positive results in hair count. In fact, by week eight, the men were exhibiting an increase of 17 hairs per cubic centimeter, which is really pretty amazing. However, those results were not sustained. As illustrated on slide 7 of a management review of the study, by week 26, the men only showed an increase of 5.6 hairs per cubic centimeter. When investigators examined the treatment area of men, they found that 12 of the 15 subjects (80 percent) exhibited increased hair growth.

As we noted in our earlier post, “Is a New Medical Treatment for Hair Loss on the Way?”, there is good reason to approach JAK inhibitors with caution. These drugs work by suppressing the activity of the immune system, which can have serious side effects, including infections. That’s one reason we spent time considering the Safety Summary released by Aclaris. While it stated that ATI-502 “was generally well-tolerated,” it also disclosed that more than one subject out of this relatively small sample experienced vertigo, upper respiratory infection, neck pain and alopecia (hair loss).

These may not be deemed by Aclaris to be “serious adverse events,” but hopefully this will prompt further study.

What Comes Next

Aclaris has already decided to extend this study to 12 months, with results expected before the end of 2019. Beyond that, Aclaris announced that it has developed a topical solution with a significantly higher concentration of ATI-502. Instead of the 0.46 percent formula, the strongly concentration could be as high as 2 percent. They are considering an additional clinical trial possibly as early as the first half of 2020 to determine the best dosage. Not surprisingly, given the results of this study, Aclaris is considering a female focus for that next clinical trial.

The slow progress of Aclaris is a great illustration of why we caution that the scientific discoveries we post about here offer exciting possibilities for future generations, but are unlikely to present realistic options for men and women experiencing hair loss today. If you are seeking expert hair restoration guidance and can’t wait a decade or more, contact Dr. Bernard Arocha.