Dutch antitrust regulators are investigating whether Biogen abused a dominant position in multiple sclerosis treatment by reserving its Stratify blood test for patients treated with its own drug. The Netherlands Authority for Consumers and Markets, known as ACM, confirmed the investigation in a statement on November 6, reported the same day by MLex and in depth by STAT on November 10. Biogen had first disclosed the Dutch probe in a regulatory filing on October 28.
Stratify detects antibodies to the JC virus, which can cause progressive multifocal leukoencephalopathy, a rare brain infection that may be fatal or cause severe disability, in patients taking medicines containing natalizumab. Regular testing is part of safe treatment with natalizumab, the active ingredient in Biogen’s Tysabri. Biogen developed the test and provides it free of charge, but only to patients receiving Tysabri or considering it. The ACM is assessing whether that exclusivity means patients on rival natalizumab medicines, in particular Tyruko, the biosimilar sold by Sandoz, cannot access the test on the same terms. In its November 6 statement, as reported by Competition Policy International, the regulator said restricting access to the diagnostic could prevent existing and prospective suppliers of competing treatments from operating effectively, potentially affecting drug prices, availability and patients’ treatment options. Sandoz itself offers a separate diagnostic test, ImmunoWell, without charge, according to a November 6 analysis by the law firm Van Bael and Bellis cited in that report.
The Dutch case does not stand alone. Italy’s competition authority has been investigating the same Stratify arrangement since May, also centred on Sandoz, and Sandoz welcomed the Dutch decision when it was announced in late October. The ACM emphasised that its investigation will determine whether Biogen’s conduct violates competition law and that opening an inquiry does not establish wrongdoing. For Biogen, which STAT describes as having Tysabri as its biggest-selling medicine, the risk is not only a fine: a remedy requiring open access to Stratify would remove a practical barrier that has protected the originator against biosimilar switching in two European markets.