Washington,  The US Food and Drug Administration has approved an oral drug to treat adult patients with severe alopecia areata -- a disorder that often appears as patchy baldness.

Alopecia areata, commonly referred to as just alopecia, is an autoimmune disorder in which the body attacks its own hair follicles, causing hair to fall out, often in clumps.

The drug Olumiant ((baricitinib), by Eli Lilly and Incyte, is a Janus kinase (JAK) inhibitor which blocks the activity of one or more of a specific family of enzymes, interfering with the pathway that leads to inflammation.

The once-daily pill, as a first-in-disease systemic treatment for adults with severe alopecia, is available as 4-milligrams (mg), 2-mg and 1-mg tablets. The recommended dose is 2-mg per day, with an increase to 4-mg per day if treatment response is inadequate.

The FDA said that it is the first such approval of a systemic treatment, which focuses on the entire body rather than a specific location for alopecia.

"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 in the FDA's Centre for Drug Evaluation and Research.

"Today's approval will help fulfil a significant unmet need for patients with severe alopecia areata," Marcus added.

The approval was based on two studies where at 36 weeks, 17-22 per cent of patients taking 2 mg of Olumiant per day and 32-35 per cent of patients taking 4-mg of Olumiant per day achieved 80 per cent or more scalp hair coverage, compared to 3-5 per cent taking placebo.

Olumiant is not recommended for use in combination with other JAK inhibitors, biologic immunomodulators, cyclosporine or other potent immunosuppressants. It also comes with warnings and precautions including recommending close monitoring for the development of signs and symptoms of infection during and after treatment; evaluating patients for active tuberculosis infection and testing for latent tuberculosis prior to treatment with Olumiant; and the potential for viral reactivation.A

In addition, other warnings and precautions include hypersensitivity (allergic reactions), gastrointestinal perforations (tears in stomach or intestine), and laboratory abnormalities including low white and red blood cell counts, liver enzyme elevations and lipid elevations.

Olumiant was originally approved in 2018. It is approved as a treatment for certain adult patients with moderately to severely active rheumatoid arthritis. Olumiant is also approved for the treatment of Covid-19 in certain hospitalised adults.