Biogen (BIIB.US) faces pressure in its MS business: Its Italian subsidiary faces a surprise antitrust inspection and is accused of abusing testing bundling sales to prevent competition.

The Italian Competition and Market Authority (AGCM) officially announced the launch of an antitrust investigation against Biogen Italia and its US parent company Biogen (BIIB.US), accusing them of alleged abuse of dominant market position by bundling a medical test for patient safety screening and systematically preventing the entry of the competitor Sandoz's low-cost biosimilar drug into the Italian multiple sclerosis (MS) treatment market. Investigators, with the assistance of the Italian Financial Police's Anti-Trust special unit, conducted a raid at Biogen's office in Milan on the morning of May 26th local time. Biogen responded to the investigation by stating through email that the company is "fully cooperating with the authorities' investigation," confirming that AGCM representatives had visited their Milan office on Tuesday morning. AGCM's official statement explicitly referenced Article 102 of the Treaty on the Functioning of the European Union (TFEU), which prohibits companies from abusing their dominant market position and is one of the core pillars of EU competition law. According to the investigation launched by AGCM, Biogen Italia and its US parent company are accused of "excluding the competitor Sandoz from supplying in the multiple sclerosis drug market based on the active ingredient natalizumab, violating Article 102." Pressure on Biogen's MS business AGCM pointed out in their statement that Sandoz's Tyruko is priced "at least 20% lower" than Biogen's Tysabri. This price difference needs to be measured within the specific treatment cost framework. AGCM particularly emphasized a key detail in their announcement: the market price for each pack of natalizumab drugs is "more than 1,000 euros (approximately 1,164 US dollars)," and treatment "is only carried out in public hospitals over long treatment periods." MS patients using natalizumab typically require intravenous infusions every four weeks, meaning the annual cost of treatment for a single patient could exceed 13,000 euros. Applied to thousands of natalizumab users nationwide in Italy, the annual saving of "at least 20%" corresponds to tens of millions of euros. To fully understand the business motives behind Biogen's actions, the antitrust investigation must be placed within the company's financial landscape. According to public financial data, Biogen achieved approximately 9.89 billion US dollars in revenue for the full year 2025, exceeding market expectations with around 2% year-over-year growth. However, this seemingly robust number masks a structural decline in its MS business sector. In the first quarter of 2026, Biogen's sales of MS treatment drugs (including Tecfidera and Tysabri) decreased by 19% year-over-year to around 1.12 billion US dollars, with Tysabri recording quarterly revenue of about 373 million US dollars, a decrease of approximately 19.4% year-over-year. The decline was not unexpected. In their first quarter 2026 financial report, Biogen had already warned of "continuing competition from European biosimilars" for Tysabri. Looking back at the fourth quarter of 2025, Tysabri's quarterly revenue still exceeded market expectations (actual 398 million US dollars vs. expected 349 million US dollars), indicating that the accelerated competitive impact was mainly concentrated in early 2026. For a company undergoing strategic transformation through new drugs (such as the Alzheimer's drug Leqembi), every lost dollar of MS revenue is squeezing its window of transformation and capital space. AGCM's antitrust logic against Biogen AGCM systematically outlined the preliminary legal characterization of Biogen's behavior in their announcement: Biogen is alleged to hold a dominant market position in the supply of the anti-JCV test (Stratify) because until 2022, this test was the only authorized method for screening, and had effectively become the reference standard in the medical field. In this context, Biogen is alleged to have used this test as leverage, by bundling the use of the test with the purchase of their own drug (Tysabri), and refusing to provide commercial services for the test to patients using the competitor's biosimilar drug (Tyruko), thereby excluding and/or restricting competition from Sandoz. In 2006, Biogen's Tysabri (the original natalizumab drug) was granted marketing authorization in the European Union, and for the following 14 years, Biogen had been the sole supplier in the global market for natalizumab, establishing a complete closed loop from drug production to patient safety monitoring. This "monopoly period" was broken in September 2023 the European Medicines Agency (EMA) approved Sandoz's development of Tyruko (a biosimilar of natalizumab), the world's first biosimilar approved for multiple sclerosis treatment. In early 2024, with the critical patent expiration of Biogen on natalizumab, Sandoz began efforts to promote Tyruko in Italy. However, after two years, Tyruko's penetration in the Italian market had not met expectations. Documents from AGCM's investigation reveal a key causal chain, explaining the root of this "market failure": patients receiving natalizumab treatment, due to the drug's potential rare but fatal side effect progressive multifocal leukoencephalopathy (PML), must undergo regular anti-JCV antibody testing before and throughout the treatment period to assess PML risk. Biogen controls the anti-JCV test called Stratify which remained the only authorized screening tool for this purpose until 2022, and had established a deep clinical reliance in the medical field. The core of AGCM's accusation is: Biogen is alleged to have bundled the use of the Stratify test with the purchase of Tysabri, and reportedly refused to provide the test in a commercial manner to patients using Tyruko. This means that when doctors in Italian public hospitals wish to prescribe the cheaper Tyruko for patients, they face a dilemma continue using Tysabri to ensure patients have access to the established Stratify test or switch to Tyruko but bear the clinical risk of discontinuing the test. For neurologists treating severe, rapidly progressing MS patients, this choice is almost unequivocal. It is worth noting that although alternative testing methods have been authorized since 2022 Sandoz supported the introduction of the ImmunoWELL JCV test by Medicover Biogen's Stratify test, with over 15 years of clinical use history and deep clinical dependence in the medical field, still effectively holds the dominant market position. AGCM's investigation of Biogen is based on this "factual dominance," rather than relying on legal monopoly authorization. Natalizumab is an effective MS treatment drug for patients with severe and rapidly progressing conditions. However, its most alarming side effect is PML a severe demyelinating disease of the central nervous system caused by JC virus infection, with a high mortality rate. Not all patients receiving natalizumab treatment face the same PML risk. Medical research has established a mature risk stratification system: by testing the levels of anti-JCV antibodies in a patient's blood, individuals can be classified into three categories based on risk seronegative (very low PML risk), low index positive (moderate risk), and high index positive (high risk). This testing is not a one-time event patients need baseline testing before treatment initiation and regular retesting throughout the treatment period (often lasting several years). In this context, the anti-JCV testing is not an "optional" auxiliary diagnosis, but an integral safety barrier in the natalizumab treatment plan. When approving natalizumab, the EMA explicitly required the incorporation of PML risk monitoring into the Risk Management Plan (RMP), including mandatory anti-JCV antibody testing. AGCM's investigation revealed that Biogen allegedly exploited this "inseparability." During the 15-year exclusive sales period of Tysabri, Biogen established a vertically integrated system from drug supply to testing services patients used Tysabri, accompanying it with the Stratify test, and this process had become a fixed practice in the hospital system. The establishment of this system itself was not a problem providing patients with accompanying safety assurances during the patent period is both a business strategy and a component of the drug risk management plan. However, after Sandoz's Tyruko entered the market in 2024, Biogen was alleged to have refused to transform the Stratify test from the "accompanying service" of Tysabri into a stand-alone "commercial product." According to AGCM's preliminary assessment, this meant: if an Italian hospital wanted to purchase Tyruko to save on drug expenses, their patients would not be able to access the clinically trusted Stratify test - Biogen's policy reportedly forced doctors to choose between "familiar testing + expensive drug" and "cheap drug + unfamiliar testing." In neurological clinical practice, the answer to this choice was almost predetermined. The PML risk for MS patients is real and deadly once PML occurs, the mortality rate can be as high as 23%, with survivors often left with severe neurological deficits. Faced with this risk, no neurologist would easily abandon a clinically validated testing system in use for 15 years to switch to a relatively unfamiliar alternative especially when the decision involved "changing drugs" rather than "changing tests."