Sandoz AG & Ors v Biogen MA Inc. [2024] EWHC 2567 (Pat)
Nataluzimab is an effective antibody treatment for multiple sclerosis. A rare, but potentially devastating side effect of treatment, is development of progressive multifocal leukoencephalopothy (“PML”). PML is caused by the John Cunningham Virus (“JCV”), a virus that is widespread in the general population and generally benign. However, in patients with compromised immune systems, JCV can reactivate leading to development of PML.
Biogen, the original developer of nataluzimab, patented a method for assessing the risk of PML. The method comprised using an assay to determine the anti-JCV antibody titer in a blood or serum sample taken from a patient, wherein the result was expressed as an index value, and determining the patient to be at high risk of PML where the index value was greater than 1.5. Biogen provided it assay free of charge to clinicians.
Sandoz developed a biosimilar version of nataluzimab and wanted to offer its own assay for assessing risk of PML upon launch of its biosimilar. It therefore sought to revoke Biogen’s patent. Its invalidity attacks included classical insufficiency, namely that the skilled team could not produce an assay in which an index value of 1.5 represented the same anti-JCV antibody titer as it did in the assay disclosed in the patent, and obviousness. Faced with further divisional applications, Sandoz also sought an Arrow-type declaration that the PCT did not disclose an assay clearly and completely enough for the skilled person to use to determine PML risk in line with the PCT’s teaching. Biogen counterclaimed for threatened infringement.
Mellor J found the patent invalid for insufficiency but dismissed the claim for declaratory relief. He found that the Sandoz assay would have fallen within the claim under the doctrine of equivalents but that there was no infringement as Sandoz was not going to use the method in the UK.
The case is of interest for the discussion of insufficiency, declaratory relief and territorial aspects of infringement.
Kathryn Pickard was instructed for Sandoz and Tom Alkin for Biogen.