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Mind the Overlap

16 August 2018

Many inventions require their features to be defined in terms of a numerical range. For example, a manufacturing process may be operable over a range of temperatures, or a material composition may be produced using components combined in a range of proportions. A patent application usually provides one or more examples of the working invention across the stated range. However, it can’t be taken for granted that the patent application provides an enabling disclosure across the entire claimed range, particularly where there are multiple competing numerical ranges. A subsequent patent application within or overlapping those ranges may therefore be deemed novel in certain circumstances.

A recent decision by the Court of Appeal (Jushi Group v OCV [2018] EWCA Civ 1416) brings more clarity to the UK’s approach regarding novelty in the case of overlapping numerical ranges.  The decision, by LJ Floyd, with LJ Kitchin and LJ Henderson in agreement, relates to an appeal by Jushi Group Co., Ltd (Jushi) from the Intellectual Property Enterprise Court’s dismissal of an action brought by Jushi to revoke a patent belonging to OCV Intellectual Capital, LLC (OVC), and consequent upholding of OCV’s counterclaim for threatened infringement.

OVC’s patent relates to a glass fibre composition, such as is commonly used as reinforcement in composite materials.  The claims characterise the composition as requiring certain components in certain amounts expressed in ranges, including a CaO/MgO ratio of less than or equal to 2.

The case revolved around a particular prior art document, referred to as “Neely”.  It was common ground that Neely disclosed the same components as the patent, in ranges that fell within or overlapped the corresponding ranges in the claims.

However, the patent specification acknowledged Neely, and made particular reference to an example in Neely that fell remarkably close to the claimed composition, but that testing had shown failed to provide the same benefits. In one instance, the cited example in Neely used a CaO/MgO ratio of 2.14, seemingly very close to the claimed ratio of less than or equal to 2.

By way of background, the Court of Appeal has recently clarified the scope of numerical ranges in patent claims in the Smith & Nephew Plc v Convatec Technologies Inc decision (as reported by us), stating that whilst whole numbers can “imply a range of values extending beyond the integer”, ultimately the specification must be interpreted in view of the “particular degree of exactitude” that would be understood by the skilled person.

Jushi argued that a ‘whole number convention’ should be applied, such that 2 includes the range 1.5-2.5. However, in view of the explicit comparison to the example in Neely, the Court took the view that “the obvious conclusion that the skilled person would draw is that the patentee’s ranges were exact, and not meant to be broadened”.  This claim interpretation ensured novelty over the specific example, and consideration then fell to the issue of novelty for the narrower and overlapping ranges.

Jushi argued that the disclosed ranges constituted a “compositional space” that anticipates all possible combinations of constituents derivable within the stated ranges, and that the “worked examples in Neely were not being disclosed in isolation but as examples of a broad disclosure”.  This was ultimately unsuccessful, perhaps unsurprisingly, since it is well established that a broad generic disclosure in the prior art does not take away the novelty of a claimed more specific one.

At first instance HHJ Hac, on applied the EPO’s ‘serious contemplation’ test to determine whether the skilled person would be able and reasonably expected to operate within the overlap. Having considered the complexity of ingredients, multiple constituent ranges, and sensitivity of the manufacturing process, Hacon determined this was not the case and that the claimed range was novel.

The Court of Appeal expressed reservations over the use of the ‘serious contemplation’ test, particularly if it were considered to relax the standards set in Synthon and Dr Reddy’s and move towards a test of inventiveness. Whilst the Court acknowledged that the serious contemplation test did “not differ materially from the conventional approach to novelty expounded in Synthon and Dr Reddy’s … it is better to take these cases as the relevant yardstick”.  The Court of Appeal therefore came to the same conclusion, although by a slightly different route.

Turning to the issue of inventiveness, the Court went on to state that for the patent to lack obviousness over Neely, in light of the complexity of the formulation and the field of endeavour, evidence would be required “that the skilled person would make the relevant choices of values in the combination necessary to do so, whilst at the same time not taking other constituents out of range”.  No evidence was provided, and so the appeal was dismissed.

This case demonstrates the UK Court’s preference for their own approach, rather than the EPO’s approach to judging novelty in numerical ranges. It is also a useful reminder when drafting a specification where numerical values are used in the claims, that clear guidance should be provided on how such values should be interpreted.


Dr. David Stanier
Advanced Engineering Group

If you require further information on anything covered in this briefing, please contact Dr David Stanier (; +44 1179 253 030) or your usual contact at the firm. This publication is a general summary of the law. It should not replace legal advice tailored to your specific circumstances.

© Withers & Rogers LLP, August 2018