Leflunomide or the Risky Life of a Generic Manufacturer in Germany
In its “Leflunomid” decision of 24 July 2012 (Case X ZR 126/09), the FCJ declared a patent claim to be invalid which covered a combination of leflunomide and teriflunomide, on the grounds that it had long been known in the prior art (for 100 years) that some leflunomide spontaneously and unavoidably converts teriflunomide over time…