Leqselvi (deuruxolitinib) is an oral Janus kinase (JAK) inhibitor indicated for the treatment of adults with severe alopecia areata (AA). The recommended dosage is 8 mg taken orally twice daily.

Leqselvi works by targeting the JAK-STAT signaling pathway, which plays a central role in inflammatory and autoimmune processes implicated in alopecia areata. Specifically, deuruxolitinib inhibits the phosphorylation and activation of STAT proteins by selectively targeting JAK1 and JAK2. This broad inhibitory profile may contribute to its efficacy in reducing autoimmune-mediated hair follicle disruption.

In clinical studies, the most common adverse reactions reported (≥1%) included headache, acne, nasopharyngitis, elevated creatine phosphokinase, hyperlipidemia, fatigue, weight gain, lymphopenia, thrombocytosis, anemia, skin and soft tissue infections, neutropenia, and herpes infections.

Like other systemic JAK inhibitors, Leqselvi carries a boxed warning for serious risks including infections, malignancy, major adverse cardiovascular events (MACE), thrombosis, and increased all-cause mortality. It is not recommended for use in combination with other JAK inhibitors, biologic immunomodulators, cyclosporine, or other potent immunosuppressants.

For dermatologists, Leqselvi offers another systemic option for patients with severe AA, particularly those who may not have responded to or tolerated other JAK inhibitors. The twice-daily oral dosing may require added patient counseling compared to once-daily alternatives. Given the class-wide safety considerations, careful patient selection, baseline laboratory evaluation, and ongoing monitoring are critical.  Studies suggest that Leqselvi may achieve substantial hair regrowth by 24 weeks, making it a promising addition to the therapeutic landscape for this condition.