In a follow-on decision reinforcing its earlier order, the Federal Circuit in Incyte Corp. v. Sun Pharmaceutical Industries, Ltd., reversed a preliminary injunction granted by the U.S. District Court for the District of New Jersey. The district court had enjoined Sun from launching its FDA-approved drug Leqselvi, a deuterated version of ruxolitinib for treating alopecia areata (AA), based on Incyte’s assertion of U.S. Patent No. 9,662,335. The Federal Circuit found that Incyte failed to establish irreparable harm—a required element for injunctive relief under Winter v. Natural Resources Defense Council, 555 U.S. 7 (2008)—rendering the injunction improper.
Background
Incyte’s ’335 patent covers deuterated ruxolitinib compounds, and the dispute arose after Sun secured FDA approval in July 2024 to market Leqselvi for AA. Incyte, which is still in early development stages for a topical version of the drug, moved to preliminarily enjoin Sun. The district court granted the motion, primarily crediting Incyte’s argument that Sun’s launch would grant it a “head start” and erode Incyte’s competitive position before its own product could reach the market.
The Federal Circuit’s Analysis
Writing for the panel, Chief Judge Moore found the district court’s irreparable harm analysis clearly erroneous. The court underscored that preliminary injunctions require a showing that harm is likely absent an injunction, not merely speculative or inevitable.
While the Federal Circuit recognized that in some cases a first-mover advantage and loss of “sticky” customer relationships may constitute irreparable harm (Bio-Rad Labs., Inc. v. 10X Genomics Inc., 967 F.3d 1353 (Fed. Cir. 2020); Natera, Inc. v. NeoGenomics Labs., Inc., 106 F.4th 1369 (Fed. Cir. 2024)), the facts here were materially different. Unlike Natera, where the injunction prevented immediate entry and preserved the patentee’s imminent market position, Incyte’s product is still years away from launch—even under its most optimistic development timeline—and certainly after the ’335 patent’s expiration in December 2026.
This distinction proved fatal to Incyte’s argument. As the court explained, “[b]ecause Incyte cannot enjoin Sun from launching after its ’335 patent expires, Sun’s multi-year head start is inevitable regardless of any injunction.” Thus, any advantage Sun might gain from launching before Incyte was not attributable to the absence of an injunction, but to the natural expiration of the patent.
Comparison to Earlier Decision
This ruling builds on the court’s prior order on April 9, 2025, vacating the injunction without a full opinion. Both decisions underscore a consistent message: patent holders must offer concrete, non-speculative proof of irreparable harm that an injunction can actually prevent. A delay in entry that would happen regardless of judicial intervention—because of patent expiration or the plaintiff’s own development delays—does not suffice.
Key Takeaways
- Inevitable Market Entry Is Not Irreparable Harm: When a competitor’s entry into the market is inevitable post-patent expiration, courts will be reluctant to find that harm from early entry is “irreparable.”
- Development Timelines Matter: A patent holder that is years away from commercial launch faces a high hurdle in arguing that it will suffer imminent harm absent an injunction.
- First-Mover Advantage Is Contextual: While first-mover advantage can support injunctive relief, it must be tethered to a plausible timeline and preventable disruption.
This decision reflects the Federal Circuit’s increasing scrutiny of the evidentiary basis for irreparable harm, particularly in the pharmaceutical and biotech space. Litigants seeking preliminary injunctions would be wise to present a realistic commercial timeline and show how the injunction meaningfully alters competitive dynamics within the remaining life of the patent.
By Charles Gideon Korrell