The Netherlands Authority for Consumers and Markets (ACM) has opened a formal investigation into pharmaceutical manufacturer Biogen for potential abuse of a dominant market position involving Multiple Sclerosis (MS) treatments and associated diagnostic testing.
The inquiry centers on the distribution terms of Biogen’s proprietary “Stratify” anti-JCV blood test in the Netherlands. The active substance natalizumab, sold by Biogen under the brand name Tysabri, carries a risk of triggering progressive multifocal leukoencephalopathy, a life-threatening viral brain disease. The Stratify test measures anti-JCV antibodies to assess this infection risk before and during treatment.
The ACM is examining allegations that Biogen restricts access to the Stratify test exclusively to patients currently taking Tysabri or considering it. By withholding the test from patients taking competing or biosimilar natalizumab-based therapies, Biogen may be leveraging its diagnostic tool to block rival pharmaceutical suppliers from competing on equal terms. The regulator noted that tying diagnostic access to brand-name drug usage could artificially restrict market entry, limit purchasing options for healthcare providers, reduce patient choice, and elevate costs across the healthcare system.
Under EU and Dutch competition law, possessing a dominant economic position is lawful, but exploiting that market power to impose unfair commercial conditions or foreclose competitors is strictly prohibited. The ACM emphasized that its investigation remains ongoing and that opening proceedings does not prejudge whether a statutory breach occurred.
The Dutch probe follows a parallel investigation launched earlier by Italy’s competition authority, the Autorità Garante della Concorrenza e del Mercato (AGCM). The two European regulators are coordinating closely to evaluate Biogen’s distribution practices across member states. The enforcement action reflects a broader regulatory push by European antitrust agencies to ensure transparency, affordability, and fair competitive conditions within the pharmaceutical sector.