A New Jersey federal court has handed down an injunction in response to a patent infringement lawsuit filed by Incyte Corporation against Sun Pharma, delaying the U.S. launch of Sun's newly approved alopecia drug, Leqselvi.
India-based Sun got the FDA nod for Leqselvi (deuruxolitinib) 8 mg tablets for the treatment of adults with severe alopecia areata in late July. Just days later, according to Sun, the company was informed about motion seeking a preliminary injunction filed in the U.S. District Court of New Jersey by U.S.-based Incyte to prevent the launch of Leqselvi, which the court granted on November 1. Incyte claims Leqselvi infringes on its patent, known as ’335 Patent, which is set to expire in December 2026.
Incyte's JAK inhibitor, branded Jakafi (ruxolitinib), is approved for specific blood cancers and most recently won approval for graft-versus-host disease in 2021. Incyte also markets ruxolitinib as a topical cream, branded Opzelura, for the treatment of certain types of atopic dermatitis and vitiligo. According to the lawsuit, while Incyte was investing into R&D for ruxolitinib, it also discovered another highly effective JAK inhibitor identified as baricitinib, which it licensed to Eli Lilly in 2009. In 2022, the FDA approved baricitinib as the first-ever systemic treatment for adults with severe alopecia areata — and Incyte is still earning royalties from Lilly.
The crux of the lawsuit stems from Sun's practice of taking FDA-approved drugs already developed by other companies and modifying their structure via 'deuteration' — replacing of one or more of the molecule’s hydrogen atoms with deuterium, aka 'heavy hydrogen.' This is the case with Leqselvi, except that Incyte says that deuterated ruxolitinib is already patented in its ’335 Patent — and the court agreed.
Sun "respectfully" disagrees with the decision and intends to immediately appeal. Sun can't launch Leqselvi in the U.S. until the company gets a favorable court decision or the patent expires.