Dive Insight:

Lilly will now have to persuade the FDA that baricitinib’s ability to regrow hair — and, perhaps, improve patients’ quality of life as well — outweighs the potential risks that come with treatment. The drug is part of a class of inflammatory disease therapies known as JAK inhibitors that are cleared for conditions like rheumatoid arthritis but have increasingly drawn scrutiny from regulators because of safety concerns.

The group of medicines — which include baricitinib, Pfizer’s Xeljanz and AbbVie’s Rinvoq — already carry warnings about the potential for infection, malignancies and blood clots. The FDA only approved a lower, less effective dose of Olumiant in 2018, for example, because of such side effects. And new concerns emerged in January when a large study found that patients taking Xeljanz had a higher risk of heart complications and cancer.

U.S. regulators are responding with caution. Earlier this month, the agency pushed back deadlines for reviewing additional uses of Olumiant in eczema and Xeljanz for a rare type of arthritis. The FDA also delayed its action deadline for an experimental JAK inhibitor from Pfizer for eczema.

That increased scrutiny could have implications for Lilly and rivals Pfizer and Concert Pharmaceuticals. Each aim to bring JAK inhibitors to market for alopecia areata, a condition that affects as many as 147 million people worldwide but only has off-label treatments such as immunosuppressants — or hair regrowth methods like minoxidil — available. Lilly’s drug is the first of its kind to succeed in late-stage testing, though Pfizer and Concert’s treatments are also in Phase 3 trials.

Lilly and Incyte said the safety findings in the Phase 3 hair-loss studies were consistent with the known profile of Olumiant. The most common side effects were respiratory infections, headache and acne. There were no deaths or reports of blood clots in the veins, the companies said.

The two studies looked at patients who had at least 50% hair loss on the scalp and had an episode of the disease lasting at least six months but not more than eight years. Researchers tested both a 2 mg and a 4 mg dose over nine months and found that both were significantly better than placebo.

In the BRAVE-AA1 trial results Lilly announced this week, 35% of patients on the higher dose of baricitinib had hair coverage across at least 80% of their scalp, compared with 22% on the lower dose and 5% in the placebo group. In the other study, BRAVE-AA2, 33% of patients on the higher dose met that mark, compared with 17% on the lower dose and 3% on placebo.

Lilly is also looking out for changes in patients’ anxiety and depression after treatment, which could be crucial in determining the benefits of treatment. Detailed results from both studies will be presented at medical meetings and published in a peer-reviewed journal later this year.