Simpson Thacher Files Lawsuit and Preliminary Injunction Motion in False Advertising Dispute
On February 23, 2026, Simpson Thacher filed a lawsuit and a motion for a preliminary injunction on behalf of Bayer HealthCare LLC (“Bayer”) against Johnson & Johnson and Janssen Biotech, Inc. in the U.S. District Court for the Southern District of New York.
The lawsuit challenges promotional claims regarding J&J’s prostate cancer drug ERLEADA® that rely on a flawed real-world data analysis and falsely portray the product as superior to Bayer’s NUBEQA®. Specifically, J&J published a press release claiming a “51% reduction in risk of death” for patients treated with J&J’s ERLEADA® compared to patients treated with Bayer’s NUBEQA® based on a retrospective analysis that Bayer contends is scientifically unreliable and methodologically flawed.
The preliminary injunction motion seeks to halt dissemination of the challenged promotional materials and prevent further misleading comparative advertising. The action asserts claims under the Lanham Act and seeks injunctive relief and damages based on false and misleading commercial claims directed at healthcare providers and patients in the competitive prostate cancer treatment market.
The Simpson Thacher team includes Lynn Neuner, Laura Brett, Simona Strauss, Nicholas Cunha, Kate Rogers and Kelsey Shelofsky.