Selection patents disclose a class of compounds along with a claim that the members of that class have a specific feature or quality. Under the old law, in order to obtain a patent for a single compound or subclass of compounds of a prior disclosed class, it had to be shown that there was a previously undiscovered advantage (or lack of a disadvantage) which that compound or subclass can fairly be said to possess.

In a unanimous decision the Court of Appeal rejected this test and made it easier for patentees to protect their selection patents. The European Patent Office (EPO) test was adopted; novelty will be maintained if the invention is not individually described in the prior art and an inventive step will exist where there has been a technical advance in the art.

Factual background to decision

Dr Reddy applied to revoke Eli Lilly's EP (UK) 0454436 (the Patent) on the grounds that it lacked novelty and was obvious in light of a previous British application 1,533,235 (235) and was obvious over a review article published in 1980 by a Lilly scientist (which was essentially an argument on the evidence). There was also a contingent attack on sufficiency which presents no interesting point of law. Floyd J gave the judgment at first instance rejecting each of the attacks and dismissing Dr Reddy's appeal.

The Patent and the Prior Art

The Patent covered a single compound known as olanzapine. Olanzapine is a widely used anti-psychotic agent for the treatment of schizophrenia. The Patent acknowledges the 235 application which discloses a wide class of thienobenzodiazepine compounds as having useful central nervous system activity.

The Markush formula describes the possibilities within this class which amount to at least 1019 compounds. 235 then identifies a preferred class of around 86,000 compounds, names around 100 compounds and finally shows the reader 15 examples of the preparation of 15 compounds. Olanzapine is one of the 1019 compounds and also one of the 86,000 but is not mentioned specifically.

Dr Reddy's arguments

Dr Reddy said that the disclosure of Olanzapine as part of a huge class meant that under art. 54 of the EPC Olanzapine formed part of the prior art and had been made available to the public, therefore the Patent lacked novelty over the 235. Furthermore the validity of a selection patent had to be assessed under the rules set out in I.G. Farbenindustrie's Patents (1930) 47 RPC 289. For a patent to be valid:

  1. it must be based on a substantial advantage;
  2. the whole of the selected class must possess the advantage; and
  3. the selection must be in respect of a quality which can fairly be said to be peculiar to the selected group.

The Court of Appeal's decision

The Court of Appeal, led by Jacob LJ, noted that the IG rules had last been affirmed as good law before the Patents Act 1977 and that the new regime for patents was now enshrined in the EPC. The correct reasoning to apply is contained in the decisions of the EPO.


Jacob LJ rejected the idea that every chemical class disclosure discloses each and every member of that class on the basis that logic dictates it. He said that Dr Reddy's contention makes no sense. A generalised description does not disclose specific matter falling within it. Floyd J. used the following analogy; a prior disclosure of "fixing means" is not a disclosure of welding or riveting even though you could make a list of fixing means that would include these means. Jacob LJ cited Hoechst Enantiomers T-0296/87 to support this reasoning. The Board said that an individualised description is needed in order to provide the type of teaching that would be prejudicial to novelty. The Court of Appeal did not indicate what would be sufficient to amount to an individualised description but instead pointed out that the prior art in the current case is 'miles from that'.


The approach of the EPO is to look at whether there has been a real technical advance. The two key cases are AgrEvo T-0939/92 and Wyeth T-133/01. The AgrEvo case, while confirming that it is necessary to look at the technical contribution for assessing inventive step, also tells us that "a mere arbitrary choice from a host of possible solutions to the technical problem cannot involve an inventive step". It must also be credible that substantially all claimed compounds possess the required feature or activity. Wyeth added that the patent must demonstrate that purported technical improvement in selectivity has been achieved in practice in order for an inventive step to exist. The Patent was held to have clearly identified a problem over and above the vague concepts set out in the 235 and provided sufficient information and activity evidence to prove that the selection of Olanzapine was not an arbitrary one.

The decision of Floyd J and the Patent were both left intact by the Court of Appeal.


The clarification on the treatment of selection patents is very helpful (and in the author's opinion correct) and is another example of the English courts discarding their traditional approaches to certain patent issues and following the EPO (see also product by process claims and second medical use claims ).

As well as taking note of EPO law, Jacob LJ was asked to consider foreign law and was glad to find that the approach he adopted was the same as that adopted by the Oberlandsgericht, an infringement only court in Dusseldorf. However he did not find the provision of decisions from the US, Canadian, Finnish, Chinese and various Eastern European courts helpful.

In connection with an application in Virgin Atlantic Airways Limited v Premium Aircraft Interiors (UK) Limited [2009] EWCA Civ 1062 the Court of Appeal requested a full analysis of the law of Germany, Netherlands and France in relation to a specific point but more broadly on how those jurisdictions implement their law in conjunction with the law of the EPO. Use your foreign law references sparingly and wisely, they can be of great assistance in the UK Court of Appeal if this rule is followed.