Sun Pharma clears path for US launch of alopecia drug after legal victory

USA – Sun Pharma has successfully overturned a legal block that had prevented it from launching Leqselvi (deuruxolitinib), its treatment for alopecia areata, in the U.S.

The move clears the way for potential market entry, intensifying competition in the autoimmune dermatology space.

The U.S. Court of Appeals for the Federal Circuit struck down a temporary injunction imposed last November, which had halted Leqselvi’s launch following a lawsuit from rival drugmaker Incyte.

The court was unpersuaded by Incyte’s argument that Leqselvi infringed on its patent rights—even though its own drug has yet to reach market.

The court’s decision takes effect immediately, but Sun Pharma remains cautious. In a filing with India’s National Stock Exchange (NSE), the company confirmed that the underlying patent litigation is ongoing, and it has yet to disclose specific launch plans for Leqselvi in the U.S.

Leqselvi is a JAK 1/2 inhibitor, similar to Incyte and Eli Lilly’s Olumiant (baricitinib)—the first FDA-approved systemic treatment for alopecia areata, approved in 2022.

The condition causes patchy hair loss and affects over 700,000 people in the U.S. Another competitor is Pfizer’s Litfulo (ritlecitinib), a JAK3/TEC inhibitor approved in 2023.

Incyte’s lawsuit claims that Leqselvi infringes U.S. Patent No. 9,662,335, which covers the use of ruxolitinib and its deuterated forms for treating inflammatory conditions.

Ruxolitinib is marketed by Incyte as Jakafi for blood cancers and as Opzelura in a topical form for dermatological conditions. Jakafi brought in US $2.8 billion in sales in 2024, with Opzelura contributing another US $508 million.

Leqselvi is derived from a deuterated form of ruxolitinib, and Incyte argues this technology has been a cornerstone of its research for over 20 years.

The company recently updated the court on its own development plans, including a Phase 1 trial of a foam formulation and future Phase 2/3 studies, though timelines remain confidential.

Sun Pharma acquired Leqselvi through its US $576 million acquisition of Concert Pharmaceuticals in 2023 and believes the drug offers “best-in-class” properties for treating alopecia areata.