The English Court of Appeal has confirmed that NAPP’s patent relating to its highly successful seven-day analgesic transdermal patch BuTrans was not infringed by competing patches proposed to be marketed by Dr Reddy’s and Sandoz.
The case is interesting, in particular, for the approach taken to the scope of numerical ranges included in the patent claim and for the speed with which the courts resolved the case.
The court has often been faced with the question whether a range of, say, 5 to 10 in a patent claim means exactly that or whether the numbers should be rounded or adjusted in some way. Such rounding or adjustment can in some cases make the difference between infringement and no infringement. The court will interpret the meaning and scope of the numerical claim in the light of the common general knowledge at the priority date and in the context of the patent specification as a whole. The question is: what would the skilled person/team have thought the patentee meant? This may, for example, depend on the usual practice in the technical field of the patent or on the approach taken in the examples given in the patent. In this particular case Arnold J in the High Court held – and Floyd LJ in the Court of Appeal agreed – that “10%-wt buprenorphine base” was expressed to the nearest whole number, so it extended from 9.5 to 10.5% and “10–15%-wt levulinic acid” meant 9.5 – 15.5% on the same basis. This reflected the skilled person’s “normal understanding that numbers written in this way would be treated as expressed to the nearest whole number”. The court rejected NAPP’s arguments, based on the way other information in the specification was expressed, that there should be a margin of 5%. Reference in the claim to “about” 10%-wt oleyloleate was held to allow a margin of about 1% either side so it extended from 9 to 11%, although Floyd comments that “there are obvious difficulties with trying to prescribe precise outer limits to an integer which uses the word ‘about’”. As a result, Dr Reddy and Sandoz’s products did not infringe.
As is clear from the above, the question of how numerical ranges in a patent claim are to be interpreted does not have a ‘standard’ answer; it will always depend on the circumstances.
NAPP commenced the infringement claim on 19 February 2016; it also applied for interim injunctions against Sandoz at the same time and against Dr Reddy’s shortly thereafter. On 16 March 2016 an expedited trial was fixed for 7/8 June 2016. Dr Reddy’s and Sandoz then agreed not to launch their products pending determination of the claim. The Court found that there was no infringement, but an interim injunction was nevertheless put in place until 16 August 2016 to allow NAPP to appeal. At the conclusion of the appeal hearing on 2 August 2016 the Court of Appeal stated that it intended to dismiss the appeal. Reasons were given in writing later, on 1 November. As Lord Justice Floyd pointed out this meant that a final decision had been reached in the Court of Appeal in under six months from the issue of proceedings.
The ability of the court to move so fast in this case was due in part to the fact that validity was not in issue. Nevertheless, this speedy decision, despite the summer break, illustrates once again the flexibility and commercial approach of the English courts, which is certainly a factor in the popularity of the English courts as a patent venue.
Case: NAPP Pharmaceutical Holdings Ltd v Dr Reddy’s Laboratories (UK) Ltd and Sandoz Ltd  EWCA Civ 1053
If you have any questions on these or other IP issues, do please contact Tom Lingard, Partner and Head of Intellectual Property, or Charlotte Tillett, Partner and Head of Life Sciences, who will be happy to discuss.