The US Food and Drug Administration (FDA) has approved Sun Pharmaceutical’s oral janus kinase (JAK) inhibitor, Leqselvi (deuruxolitinib), to treat adult patients living with severe alopecia areata.

Affecting around 700,000 people in the US, alopecia areata is an autoimmune disease that occurs when the immune system attacks hair follicles, resulting in partial or complete loss of hair on the scalp and body.

The twice-daily oral JAK1 and JAK2 inhibitor, Leqselvi, is designed to interrupt the pathways that are thought to contribute to hair loss in severe alopecia areata.

The FDA’s decision was based on results from two phase 3 clinical trials, THRIVE-AA1 and THRIVE-AA2, which evaluated the regrowth of scalp hair after 24 weeks of dosing using the Severity of Alopecia Tool (SALT) score in 1,220 patients with alopecia areata who had at least 50% scalp hair loss for more than six months, in addition to data from two open-label, long-term extension trials.

Patients were randomised to either receive 8mg twice daily or 12mg twice daily of Leqselvi or placebo.

The study met its primary endpoint after 24 weeks, with more than 30% of patients receiving Leqselvi experiencing 80% or more scalp hair coverage and a SALT score of 20.

In addition, for up to 25% of patients, almost all of their scalp hair returned at 24 weeks with up to 90% of hair coverage.

Commenting on the approval, Marek Honczarenko, senior vice president and head of development, Sun Pharma, said: “This [FDA approval] validates our team’s capability to effectively bring treatments from research and development to approval in a way that is meaningful for physicians and patients.”

President and chief executive officer of the National Alopecia Areata Foundation, Nicole Friedland, welcomed the approval of Leqselvi and marked it as “a significant step for the alopecia areata community”.