Oral JAK3 Inhibitors Prompt Alopecia Areata Hair Regrowth

Posted by Sarah

In this article: Hair Loss | Alopecia


A Pfizer-supported hair loss study has shown that oral JAK3 inhibitors may have the potential to regrow hair in cases of moderate-to-severe Alopecia Areata.

Hair regrowth of scalp hair, eyebrows and eyelashes was witnessed during the 24-week double-blind, randomised Phase II clinical trial. The results were announced by Emma Guttman-Yassky, MD, PhD, of Icahn Medical School at Mount Sinai, New York, during a presentation at the 2018 Inflammatory Skin Disease Summit in Vienna.


Researchers are now suggesting this could be a long-term solution to the various types of Alopecia Areata - autoimmune-related hairloss conditions - once the potential effects of stopping treatment are also properly investigated.

JAK1 versus JAK3 inhibitors


According to Guttman-Yassky's presentation and abstract information published in the Wiley online journal on 10th December 2018, two different JAK inhibitors were pitted against each other in a 142-person, placebo-controlled trial. These were a JAK3 inhibitor named PF‐06651600, and the TYK2/JAK1 inhibitor named PF‐06700841; both were administered orally, as was a placebo to the third arm of trial participants.

A 200mg dose of JAK3 was taken once per day for the first four weeks, then the group was switch to a 50mg per day dose for the remaining 20 weeks. Those taking the JAK1 inhibitor took one 60mg per day dose for the first four weeks before switching to a 30mg per day dose for the rest of the trial. All test subjects had Alopecia Areata (patchy hair loss of scalp only) or Alopecia Totalis (baldness of head only) which affected a minimum of 50 per cent of their scalp, at the time of starting the trial. Their hairloss and hair regrowth progress of scalp hair was monitored throughout using the severity of alopecia tool (SALT).

Statistically significant improvements were noted in both active JAK inhibitor groups at weeks 6 (JAK3 inhibitor) and week 4 (JAK1 inhibitor) when these pulled away from the placebo results.

Following 24 weeks of consistent treatment, the group taking TYK2/JAK1 inhibitor (PF‐06700841) saw a mean change in hair growth from baseline measurements, of 49.5, whilst the JAK3 inhibitor group saw an mean increase of 33.6.

Dr. Guttman-Yassky mentioned during her presentation that patients taking both the JAK inhibitor medications had also seen improved growth to their eyelashes and eyebrows, which was not seen in the placebo group.

Ongoing development with FDA assistance


PfizerPfizer has already been granted a 'breakthrough designation' by the USA's medical regulatory board, the FDA (Food & Drug Administration) for the JAK3 inhibitor used in this trial. What this means is that trial research will be reviewed by the relevant FDA boards quickly in order to help move the product along as fast as possible.

The FDA is lending similar support to two other companies - Aclaris Therapeutics and Concert Pharmaceuticals - with regards fast-tracking their potential JAK inhibitor, or JAK inhibitor-based, treatments for all forms of Alopecia Areata. This is a key area of interest for the American body due to the current "unmet need" given, despite various Alopecia Areata treatment options existing mostly for adults with the scalp-only phenotype, none are yet FDA approved.

Anyone concerned with sudden and/or patchy hair loss should seek assistance from their GP; however, if this is confined to just the scalp, with rounded bald spots appearing, a hair loss specialist can also offer counsel and treatment recommendations, where appropriate.

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The Belgravia Centre

The Belgravia Centre is a world-renowned group of a hair loss clinic in Central London, UK. If you are worried about hair loss you can arrange a free consultation with a hair loss expert or complete our Online Consultation from anywhere in the world for home-use treatment.

View our Hair Loss Success Stories, which includes the world's largest gallery of hair growth photos and demonstrates the level of success that so many of Belgravia's patients achieve.

Posted by Sarah

In this article: Hair Loss | Alopecia


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