BIA comment on the Supreme Court’s ruling on Warner Lambert v Generics

On 14 November 2018, the Supreme Court handed down its judgment in the case of Warner Lambert v Generics.  One of the key issues in the case was the scope of the test of “plausibility” which relates to the information a patent must contain.


The BIA intervened in this case requesting that a balance be struck that neither unfairly penalises bioscience companies in requiring an unwarranted level of information in order to demonstrate plausibility of an invention (e.g. clinical trial data) nor permits applicants to unfairly close down areas of research through the filing of speculative patent applications providing only vague indications of possible research objectives. 


The Supreme Court was divided in its approach to the role of this test in the context of determining whether a patent is sufficient. In a majority decision (given by Lord Sumption) the Court concluded that it must be plausible that a treatment is efficacious.  The Court said that the question is not whether the invention is plausible but whether the specification discloses something that would make it plausible to a skilled person.  A bare assertion or speculation will not be enough although a patent specification that suggests something is worth trying may make it plausible if it contains such reasonable scientific grounds for expecting it might work.  According to the majority, there must a reasonable prospect that the product would work for the designated purpose which must be based on a “direct effect on a metabolic mechanism” specifically involved in the disease.  The effect need not be demonstrated by experimental evidence but could be shown by reasoning which can be deduced or inferred. 


The Court appears to have sought to apply the same rules as those of the European Patent Office, although the outcome is not entirely clear on this.  Until there are further decisions on this issue, there is for now some uncertainty on how the test will apply in practice.  It is also noteworthy that there were two strongly dissenting judgments on this issue which preferred a lower standard for plausibility.  In the light of this and the changing composition of the Supreme Court, it may not be too long before this issue comes before the Supreme Court again.


The BIA welcomes the finding in the judgment that sufficiency does not need to be shown by experimental data.   The BIA would be concerned if the effect of the decision were to reduce incentives to innovate.  Setting the burden of establishing plausibility too high risks making it difficult to secure the patent protection needed to fund research efforts. 


The BIA’s submission to the Supreme Court and this blog were produced by the BIA’s Intellectual Property Advisory Committee (IPAC).  

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