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Non-Speculative Evidence Of Irreparable Harm Is Required For Preliminary Injunction
05/20/2025Incyte Corporation and Incyte Holdings Corporation’s (collectively, “Incyte”) owns U.S. Patent No. 9,662,335, which claims deuterated versions of ruxolitinib used to treat diseases associated with autoimmune disorders. The ’335 patent is set to expire in December 2026. Sun Pharmaceutical Industries, Ltd. and Sun Pharmaceutical Industries, Inc. (collectively, “Sun”) secured FDA approval for an oral deuterated ruxolitinib product, branded as Leqselvi, to treat alopecia areata (“AA”) in July 2024. Sun was set to launch its product in October 2024. Incyte was in the early stages of developing its own deuterated ruxolitinib product for AA treatment.
Prior to Sun launching its product, Incyte sued for infringement and moved for a preliminary injunction enjoining Sun from making, using, selling, advertising, or distributing its drug Leqselvi. The district court granted the motion for a preliminary injunction. On appeal, Sun argued that Incyte failed to show that Incyte is likely to (1) suffer irreparable harm and (2) succeed on the merits.
Before the district court, Incyte argued that the launch of Leqselvi would give Sun an unjust head start over Incyte in the AA market, particularly where patients are unlikely to switch treatments for AA. The district court agreed and explained that, but for Sun’s Leqselvi, the ’335 patent would allow Incyte to bring a deuterated ruxolitinib AA treatment first to market.
The Federal Circuit vacated the injunction and reversed the district court order. Several facts were undisputed: Sun is prepared to launch; the ’335 patent expires in December 2026; and Incyte will not launch its product until at least several years after the patent expires. On appeal, Incyte argued that, without an injunction, Sun will receive an additional two years on the market and cause Incyte irreparable harm due to its loss of market share from this extended head start. In rejecting this argument, the Federal Circuit determined that Sun’s multi-year head start is inevitable, regardless of any injunction, because Incyte cannot enjoin Sun from launching after its ’335 patent expires.
Because the Federal Circuit determined that the district court erred in its irreparable harm analysis; it did not reach Sun’s likelihood of success arguments.
