A recent patent dispute between GlaxoSmithKline and Pfizer group company Wyeth did not follow the usual pattern of an injunction against the infringer's product despite a win for the patentee.
The dispute was over GSK’s meningitis B vaccine sold in the UK as Bexsero. Bexsero is a new vaccine offered in the UK to babies born to on or after May 2015. Its introduction received an enthusiastic welcome from campaign group Meningitis Now who commented:
“This is a fantastic result in the battle against the disease and one we should all celebrate.”
High demand globally has led to supply shortages, and GSK have restricted supplies to private clinics until they can ramp up production sufficiently to meet demand. Although FDA-approved for the US market for the 10-25 age group, Pfizer/Wyeth’s product Trumenba has yet to receive European marketing approval.
GSK asked the English court to declare Pfizer's patent EP(UK) 2,343,308 invalid, and Pfizer countered that GSK's product infringed.
The bacterium responsible for meningitis B, Neisseria meningitides, is a Gram-negative species with a complex membrane structure. It is responsible for about half of meningitis cases in children across Europe and the US, and can cause death within hours. There had been considerable effort for a number of years to come up with a vaccine against meningitis B with limited success. Experts in the field treated new candidates with scepticism.
Pfizer’s patent, although applied for in October 2002 and claiming priority from US filings in 2001 and 2002, was not granted until 2015. It claims a vaccine using a combination of two particular types of protein, a 2086 protein with a PorA protein, to give the widest possible protection. It is currently being opposed by GSK at the EPO.
In the English case, GSK put forward a long list of invalidity arguments, notably AgrEvo obviousness/insufficiency. Essentially this involves an argument that it was not plausible given the disclosure in the patent that invention would work across the scope of the claims. The judge explained that
“Plausibility is a "threshold test" which is satisfied by a disclosure which is "credible", as opposed to speculative.”
In cross-examination, GSK’s expert had to acknowledge that the data given in the patent showed convincing evidence of
“an interesting and serious vaccine candidate”,
and given the way the judge interpreted the claims – covering only combinations containing a functional 2086 protein – this meant that the argument failed.
Despite the win, Pfizer did not ask the court for the usual injunction to stop further sales by GSK. Clearly, if Pfizer were to use its patent to exclude Bexsero from the UK market there would be serious public health concerns. So the question of a stay pending appeal, or pending the outcome of the EPO proceedings, did not arise.