Wednesday, June 3, 2026

Italy probes Biogen over Tysabri test and market abuse claims

Italy’s competition authority AGCM has opened an investigation into Biogen and its Italian subsidiary. The case centers on allegations that the company may be abusing its market position in connection with a safety test used alongside the multiple sclerosis drug Tysabri (natalizumab).

Focus on anti-JCV testing in natalizumab therapy

According to the authority, the matter relates to anti-JCV testing used before and during treatment to assess the risk of a rare but serious side effect affecting the central nervous system. The AGCM indicated that Biogen’s conduct around this test could be shaping competition in the market for natalizumab-containing MS therapies and may disadvantage Sandoz.

Sandoz markets Tyruko, a biosimilar to Tysabri, which the authority said is sold in Italy at around 20% below the originator’s price. Tysabri lost patent protection in 2024.

On-site inspections supported by financial police

As part of the investigation, the AGCM carried out inspections at Biogen premises in Italy on May 26. The inspections were supported by a special antitrust unit of the Italian financial police, the Guardia di Finanza.

Context: testing requirements also impacted a US launch

Anti-JCV testing has previously been a practical issue for Sandoz in the United States, where a launch was delayed following a test-related holdup. Sandoz later worked with Labcorp on an alternative to a test marketed by Biogen in partnership with Quest Diagnostics.