Plausibility: The need for data in pharmaceutical patent applications


In Sandoz Ltd v Teva Pharmaceutical Industries Ltd, the High Court found in its judgment that the use of apixaban, for the treatment of thromboembolic disorders, was not plausible based on a patent specification as filed.



Bristol Myers Squibb’s (BMS’s) European patent 1427415B1 (the patent) relates to the compound apixaban, sold by BMS under the name ELIQUIS®. Apixaban is used to prevent serious blood clots from forming, for example due to an irregular heart beat or after surgery. Apixaban’s use in therapy is due to its activity as a factor Xa inhibitor.

Sandoz Ltd and Teva Pharmaceutical Industries Ltd sought to revoke the patent. Their main attack was that the patent did not make it plausible that apixaban would have any useful factor Xa inhibitory activity, or be useful in therapy in general.

BMS counterclaimed for infringement.


Plausibility and Common General Knowledge

Lack of plausibility is not in itself a ground for revocation of a patent. The issues of plausibility arise under the requirements for a claimed invention to have inventive step and to be sufficiently disclosed.

The judgment found that the analysis of plausibility should be guided by an earlier case (Warner-Lambert). Put simply, a contribution by the patentee that is in the patent specification is needed. The patentee’s contribution must be more than common general knowledge.


The Patent

The patent included a single statement that some compounds had been tested and found to have some binding affinity for factor Xa. In the High Court’s judgment, there was no link between this statement and any individual compound, be it apixaban or any other.

BMS argued that apixaban’s activity could be predicted by the skilled person as a consequence of structural considerations based solely on their common general knowledge. The High Court did not accept this argument on the grounds that the patentee’s contribution must be more than common general knowledge.



This judgment highlights the importance of including efficacy data in patent applications on filing, particularly in the pharmaceutical fields.


Chris Bond