Sun Pharmaceutical Industries plans to buy Concert Pharmaceuticals, a move that will net Sun Pharma a potential best-in-class treatment for the autoimmune disease alopecia areata.

The two companies announced a definitive agreement Thursday that has Concerta getting $576 million up front and more if the lead product candidate deuruxolitinib achieves certain sales milestones.

Concert’s deuruxolitinib is an oral inhibitor of Janus kinases JAK1 and JAK2 developed for the treatment of alopecia areata, which causes the immune system to attack hair follicles, resulting in partial or complete loss of hair on the scalp and body. The condition, which affects up to 2.5 percent of the population, has limited treatment options.

Concert has completed its evaluation of the efficacy and safety of deuruxolitinib in adults with moderate to severe alopecia areata in a phase 3 clinical trial, and two open label, long-term extension studies are ongoing in North America and Europe.

The deal is expected to close in the first quarter this year and Sun Pharma plans to submit a new drug application for the candidate to the FDA in the first half of 2023.