Two recently completed phase 3 clinical trials showed the drug baricitinib leads to hair growth for alopecia areata patients. Baricitinib is a JAK inhibitor, a class of drugs that regulates the immune system by blocking cytokine-mediated inflammation.
Some JAK inhibitors are already used to treat other autoimmune diseases like rheumatoid arthritis and psoriasis. Alopecia areata is an autoimmune disease of the hair follicles that can lead to complete baldness, including loss of scalp, eyebrows, eyelashes and body hair. The effects of the disease are emotionally devastating to patients, and there are currently no FDA-approved treatments. Disease onset is usually between the ages of 25 and 36 years old, and it's thought to be slightly more common in men.
Results from the two clinical trials, presented at the European Academy of Dermatology and Venereology 2021 Annual Meeting, were taken from 3 groups receiving a placebo or either 4 mg or 2 mg of baricitinib. Study participants taking 4 mg showed the fastest hair growth with differences between the 4 mg treatment group and the placebo noted by 16 weeks into the study. It took 24 weeks for differences between the 2 mg and placebo groups to be noticeable.
Overall, after 36 weeks of receiving treatment the goal of 80% scalp coverage with hair occurred in 21.7% and 17.3% of participants in the two trials studying the effects of 2 mg of baricitinib and 35.2% and 32.5% of participants in the 4 mg groups. By comparison, only 5.3% and 2.6% of placebo participants reached this goal in the two trials.
Adverse events that occurred in the treatment groups included upper respiratory tract infections, nasopharyngitis, urinary tract infections, and headaches, and they occurred in no more than 10% of the patients. This led researchers to conclude that adverse events are mild to moderate in severity and modestly higher in the treatment groups compared to placebo groups.
How long treatment results will last was not mentioned.