On September 8, 2026, an Illinois federal judge declined to dismiss a lawsuit filed by Walgreens and Kroger against Biogen Inc., alleging that the company unlawfully suppressed competition for its multiple sclerosis drug, Tecfidera. The court determined that the plaintiffs had presented sufficient allegations to suggest they had “suffered a concrete injury as a result of Biogen’s conduct.” ([law360.com](https://www.law360.com/cases/68d6a2bcbbdbd36f36dd582e?utm_source=openai))
This decision marks a significant development in the ongoing legal battle between the pharmaceutical giant and major U.S. pharmacy chains. The case, filed in the U.S. District Court for the Northern District of Illinois, centers on claims that Biogen engaged in anticompetitive practices to maintain its monopoly over Tecfidera, thereby preventing the entry of more affordable generic alternatives into the market. ([law360.com](https://www.law360.com/cases/68d6a2bcbbdbd36f36dd582e?utm_source=openai))
Previously, in February 2026, the same court dismissed an earlier version of the lawsuit, citing issues with the plaintiffs’ standing. However, the judge indicated that these deficiencies could potentially be addressed through an amended complaint. ([law360.com](https://www.law360.com/articles/2440796/biogen-beats-pharmacies-ms-drug-monopoly-suit-for-now?utm_source=openai))
In response, Walgreens and Kroger filed a third amended complaint in October 2025, asserting that Biogen orchestrated a “market switch” by encouraging healthcare providers to transition patients from Tecfidera to a new, nearly identical version of the drug before generic versions became available. This strategy, they argue, was designed to circumvent impending generic competition and maintain Biogen’s market dominance. ([mlex.com](https://www.mlex.com/mlex/antitrust/articles/2404622/plaintiffs-file-third-amended-us-complaint-against-biogen-over-tecfidera?utm_source=openai))
Biogen has consistently denied these allegations, contending that the pharmacies lack standing as indirect purchasers and that their claims are without merit. The company has also pointed to its ongoing efforts to protect its intellectual property rights related to Tecfidera, including litigation against generic manufacturers in various jurisdictions. ([biogen.gcs-web.com](https://biogen.gcs-web.com/node/30881/html?utm_source=openai))
The outcome of this case could have significant implications for the pharmaceutical industry, particularly concerning the strategies employed by brand-name drug manufacturers to extend market exclusivity and the legal avenues available to challengers seeking to introduce generic alternatives. As the litigation progresses, stakeholders will be closely monitoring developments to assess potential impacts on competition and drug pricing within the multiple sclerosis treatment market.