Bayer Sues Johnson & Johnson Over Prostate Cancer Drug Marketing Claims

Whippany-based Bayer has filed a lawsuit against New Brunswick-headquartered Johnson & Johnson, alleging the rival pharmaceutical company made false advertising claims about its prostate cancer drug Erleada that have damaged sales prospects for Bayer’s competing medication Nubeqa.

The complaint, filed February 23 in U.S. District Court for the Southern District of New York, contends that J&J’s new marketing campaign is causing “irreparable harm” to Bayer and threatens to erode trust in its product. At the heart of the dispute are claims about the relative efficacy of the two treatments in the increasingly competitive prostate cancer market.

“J&J made false claims regarding the efficacy of Nubeqa in an effort to increase its market share,” Bayer alleges in the lawsuit, pointing to a February 2 press release from J&J that has become the focal point of the legal challenge.

The press release in question highlighted what J&J called a “real-world head-to-head analysis” comparing survival rates after 24 months between patients treated with Erleada versus darolutamide (the active ingredient in Nubeqa), both without the chemotherapy docetaxel. According to J&J’s analysis of U.S. medical and insurance databases, patients with metastatic castration-sensitive prostate cancer who received Erleada experienced a 51% reduction in risk of death compared to those who initially received Nubeqa.

J&J reported that approximately 92% of the 1,460 Erleada patients included in the analysis were still living at the 24-month mark, compared to just under 86% of the 287 Nubeqa patients. The company has promoted these findings through multiple channels, including slideshow presentations and on its Medical Connect website for healthcare providers.

Bayer contends that J&J’s study methodology is fundamentally flawed. According to the lawsuit, the two patient groups weren’t truly comparable because most Nubeqa patients were treated off-label, creating selection bias that undermines any superiority claim. Bayer also noted the significant disparity in sample sizes—J&J’s study included five times as many patients on Erleada as on Nubeqa.

The complaint further argues that the U.S. Food and Drug Administration does not sanction the type of retrospective, real-world analysis that J&J used as a substitute for traditional clinical trials. Bayer also expressed concern that online searches, including AI-generated summaries in Google, are amplifying J&J’s claims that Erleada is more effective and that Nubeqa carries a higher mortality risk.

Bayer maintains that J&J’s claims violate the federal Lanham Act, which prohibits companies from making false or misleading statements about a product’s safety, efficacy, or characteristics. The lawsuit was filed after Bayer says J&J refused to “cease and desist its promotion of a scientifically flawed real-world evidence analysis that misinforms healthcare providers and patients.”

Both medications represent significant revenue streams for their respective companies. Both Erleada and Nubeqa are androgen receptor inhibitors designed to slow prostate cancer growth, often used alongside other treatments. Nubeqa, a key product for Bayer, received initial FDA approval in 2019 with expanded uses approved in 2022 and 2025. It generated approximately $1.92 billion in sales during the first nine months of 2025. Erleada, one of J&J’s faster-growing oncology products, was first approved in 2018 with expanded approval in 2019, and brought in $2.62 billion during the same period.

Bayer is seeking a permanent injunction to stop J&J from disseminating the analysis and its claims. The lawsuit also requests that J&J issue a “corrective press release” to dispel the claims, pay Bayer for “unjust profits,” and cover compensatory and threefold punitive damages as well as court costs.

The legal action comes shortly after both companies launched new marketing initiatives for their respective drugs. Just before J&J began its advertising campaign for Erleada last month, Bayer unveiled a marketing push for Nubeqa that included a partnership with former NFL quarterback Tony Romo.

Johnson & Johnson defended its analysis in a statement, saying, “Johnson & Johnson stands by the rigor and integrity of our real-world, head-to-head analysis… Litigation does not change data.” The company added, “Our analysis was designed to meet rigorous regulatory guidance on real-world evidence, and this legal action demonstrates Bayer’s obvious misunderstanding of methodological frameworks and real-world evidence principles.”