First Oral JAK Inhibitor Approved for Severe Alopecia Areata in Teens

The FDA approved the Janus kinase (JAK) inhibitor ritlecitinib (Litfulo) for adults and adolescents with severe alopecia areata.

Ritlecitinib is the second oral JAK inhibitor approved for alopecia areata (the first being baricitinib [Olumiant]) and the first approved treatment for adolescents 12 or older with the hair loss condition.

“While patients may start to develop symptoms of alopecia areata at any age, most people start showing signs in their teens, 20s, or 30s,” said Brittany Craiglow, MD, of Yale Medical Center in New Haven, Connecticut, in a statement from Pfizer. “Litfulo is a particularly important treatment option for younger patients with substantial hair loss, who often struggle with such a visible disease.”

Ritlecitinib targets JAK3, in contrast to baricitinib which inhibits JAK1. Laboratory studies have shown that selective inhibition of JAK3 or JAK1 “robustly induced hair growth and decreased AA [alopecia areata]-associated inflammation.” Ritlecitinib also is being evaluated for vitiligo, Crohn’s disease, and ulcerative colitis.

Primary support for the alopecia areata indication came from the phase IIb/III ALLEGRO trial involving 718 patients with ≥50% hair loss as measured by the Severity of Alopecia Tool (SALT). Investigators and patients in 18 countries participated in the randomized trial, which showed that 23% of patients randomized to ritlecitinib had ≥80% scalp hair coverage after 6 months, as compared with 1.6% of the placebo group. Efficacy results were similar for the adolescent patients ages 12 to 17 and adults.

The most common adverse events (at least 4% of patients treated with ritlecitinib) were headache (10.8%), diarrhea (10%), acne (6.2%), rash (5.4%), and urticaria (4.6%). Complete results of the study were previously reported in The Lancet.

“People living with alopecia areata are often misunderstood, and their experience is frequently trivialized as ‘just hair,'” said Nicole Friedland of the National Alopecia Areata Foundation. “However, it is a serious autoimmune disease that can have considerable negative impact beyond the physician symptoms. We believe the approval of Litfulo is a significant advancement for the treatment of alopecia areata, particularly for teens.”