BMS loses UK appeal over blood-thinning drug
Decision addresses issue of plausibility in invalidation verdict | Case marks first time that Court of Appeal judges held a patent with a single claim to a pharma compound invalid.
A London court has upheld a verdict invalidating a Bristol Myers Squibb (BMS) patent for blood-thinning medication Eliquis (apixaban), putting the spotlight once more on the justices’ approach to plausibility assessments.
On Thursday, May 4, the England and Wales Court of Appeal dismissed the appeal, in a win for Sandoz and Teva Pharmaceuticals. Both needed a BMS patent invalidated to clear the way for generic versions of apixaban.
Confirming the decision of the lower courts, Justice Richard Arnold held that the case was legally indistinguishable from Warner-Lambert v Generics (2018) and that the criterion of plausibility must be applied when determining whether the claimed invention involved an inventive step and was sufficiently disclosed.
This was the first time that Court of Appeal judges held a patent with a single claim to a pharmaceutical compound invalid for lack of plausibility, as Juve Patent reported.
It also marked the first UK decision to consider the concept of plausibility following the European Patent Office’s decision in G 2/21, handed down in March this year.
Patent revoked
The England and Wales High Court determined that BMS’ European patent number 1 427 415 entitled “Lactam-containing compounds and derivatives thereof as factor Xa inhibitor” to be invalid in April 2022, following a challenge from Sandoz and Teva.
Their central argument was that the patent did not make it plausible that apixaban would have any useful factor Xa inhibitory activity, or be useful in therapy or for any other purpose.
Justice Meade concluded the patent, which was due to expire in September that year, was invalid by reason of lack of plausibility. This also means that a Supplementary Protection Certificate (SPC) based on the patent, in force until May 2026, was also invalid.
Grounds for appeal
BMS appealed the decision arguing that—in the case of a claim to a single chemical compound—there is no requirement that the specification makes it plausible that the compound is useful.
The pharma company further contended that it was sufficient that it disclosed the structure of the compound, method of synthesis and “potential utility”.
The New York-headquartered firm also contested the judge’s application of the standard of plausibility laid down by the majority in Warner-Lambert, claiming that he “should either have applied the standard advocated by the minority or applied the standard laid down by the majority less strictly”.
‘Two sides of the same coin’
Dismissing the appeal, Justice Arnold said the case could not legally be distinguished from Warner-Lambert, adding that: “I do not understand how it is possible to determine whether a claimed invention is speculative other than by assessing whether it is plausible. They are two sides of the same coin”.
He said the judge made no error law or principle in his approach to the assessment of plausibility, and was correct in applying Warner-Lambert. In unconnected proceedings, the European Patent Office’s Enlarged Board of Appeal also recently considered plausibility in G2/21, which involved a patent covering an insecticide composition and whether post-published evidence could be used as proof for the alleged synergistic effect.
