The U.S. Food and Drug Administration granted approval to Olumiant, an alopecia treatment developed by Eli Lilly that produced hair regrowth in trials.

The agency granted approval to Olumiant, oral tablets used to treat patients with the disorder that often produces patchy baldness and affects more than 300,000 people in the United States each year, the FDA said in a release Monday.

"Access to safe and effective treatment options is crucial for the significant number of Americans affected by severe alopecia," said Kendall Marcus, director of the Division of Dermatology and Dentistry at the FDA's Center for Drug Evaluation and Research. "Today's approval will help fulfill a significant unmet need for patients with severe alopecia areata."

Alopecia areata usually presents as a few small bald patches in the head, while severe cases can include loss of all body hair, including eyelashes.

Olumiant is a Janus kinase, or JAK, inhibitor, which blocks the immune system from attacking hair follicles.