Selection Inventions - has the bar been raised or lowered?

In UK patent law, it has for many decades been the case that "selection" inventions are capable of patent protection.  The principles were first judicially established in the case of I.G. Farbenindustrie's Patents in 1930 and have become known as the IG rules.  A selection invention occurs typically in the chemical field, involving a particular chemical compound or a relatively narrowly-defined class of compounds, "selected" from a previously-disclosed broader class but not specifically identified therein.  The IG rules require that the selected compounds must have a substantial advantage of some kind, that the advantage must be demonstrated across the class and that it must be of a special character peculiar to the selected group.  Under the law at that time, there was no requirement for establishing novelty and inventive step separately; an invention had to have "subject matter" and the IG rules were propounded to avoid the prior art depriving the selected class of subject matter.

The IG rules have subsequently been followed in the UK in other cases involving selection inventions, both where the prior-disclosed field was extremely broad, and relatively narrow - a disclosure of nine particular glycols including the one used (for another purpose) in the latter invention (du Pont (Witsiepe's) application), or a mixture of two chemical isomers (Beecham Group's (amoxycillin) application) where the invention was an isolated single isomer.  Such cases have, however, been concerned with patents granted under the 1949 Patents Act.  In du Pont, it was held that the size of the initial group was not relevant in assessing novelty, although it may be relevant for obviousness.

In the recent Court of Appeal judgment in the case of Dr Reddy's Laboratories (UK) Limited (DRL) v. Eli Lilly and Co. Limited (Lilly), the IG rules have been cast aside as being "part of legal history, not as part of the living law".  In fact, the IG rules were criticised as being impractical in terms of being able to establish that the advantage of the class is demonstrated across the full breadth of the class, without exhaustive experimentation:  "If you put in your thumb and pull out a plum, how are you to say that there are no other plums in the pudding?" 

So, according to the Court of Appeal, the UK approach to selection inventions under the Patents Act 1977 must now follow the EPO approach.  For novelty purposes in the case of selection inventions, a distillation of the various Technical Board of Appeal cases has resulted in guidelines which state, among other things, that although a generic disclosure does not usually deprive specific compounds of novelty, nevertheless the extent of the prior disclosure is relevant.  Thus, for example, a selection from a single list of specifically disclosed compounds is insufficient to confer novelty.  On this basis, it is unlikely that the du Pont and Beecham selection inventions would have been held patentable in the EPO.  However, assuming that novelty can be established, the novel selection will be regarded as patentable if the selected class involves an inventive step, assessed in the usual way as for any other invention.  There is therefore no need to establish the more stringent properties required of the compounds in the selected class according to the IG rules.  So, in the EPO, novelty may be harder to establish and inventive step easier.

In the case in point, DRL had initially unsuccessfully applied for revocation of Lilly's patent (EP(UK)0454436) in the Patents Court.  The patent concerns a single chemical compound, known as olanzapine, now widely used in the treatment of schizophrenia.  One prior art reference, which was acknowledged in the introduction to the patent specification, disclosed a general formula embracing olanzapine but, theoretically, covering 10 billion billion individual compounds.  Within this broad class, a preferred class was disclosed of narrower scope but still encompassing 86,000 compounds.  Approximately 100 compounds were identified by name and 15 compounds were prepared and characterised but the only comment concerning utility referred to the broad class, stating that they had useful nervous system activity, rendering them useful in the treatment of mild anxiety states and certain kinds of psychoses.  Olanzapine was not one of the compounds either named or synthesised.  DRL contended nevertheless that olanzapine lacked novelty because it had been made available to the public through the general formula.  This proposition was firmly rejected by the Court of Appeal, partly because it was illogical and partly because it was inconsistent with EPO jurisprudence.

Turning to obviousness, the EPO invariably considers technical advance as being essential in order for an inventive step to be recognised.  In the absence of a technical advance, the EPO will regard novel compounds as being merely arbitrary alternatives to known compounds within the broader class.  The technical contribution must be assessed and, in order to be patentable, the selected class must not be arbitrary and must exhibit a hitherto unknown technical effect caused by those structural features which distinguish the selected compounds from the broader class.  An alleged technical contribution must be supported by appropriate evidence; a mere assertion is insufficient.

In the case of the Lilly patent, the Court had no problem in finding that the prior art failed to give any guidance to the skilled person concerning the efficacy of the enormous number of compounds disclosed, let alone a single compound not specifically identified.  The evidence had established that olanzapine was an improvement over earlier compounds in clinical use in terms of avoiding side effects; it also avoided causing a rise in cholesterol levels, observed in a close analogue. The technical contribution was thus established.  Since the patent covered only a single compound, there was no need to establish that its advantages were shared by other analogous compounds in a selected group.  Thus, on the facts, the appeal was dismissed.

In conclusion, it might be argued in one sense that, except for single-compound inventions, the EPO test for obviousness (requiring, as it does, that the technical advance is seen to be credible across the entire breadth of the claim) is not in reality far removed from the IG rules.  Indeed, even for a single compound invention, who is to say, without exhaustive experimentation, that there isn't another "plum to be found in the pudding"?  Perhaps the real significance lies in the question of novelty, in that EPO jurisprudence is more prescriptive than UK practice under the IG rules.  Although the EPO theoretically recognises that a generic disclosure does not take away the novelty of a specific compound falling within the scope of that disclosure, the proposition nevertheless fails where, for example, the compound is selected from a single list.  The earlier UK requirement that novelty exists provided that the compound has not been specifically prepared and characterised and (in a method invention) used in the method is now apparently consigned to history.

Ivor Harrison
Life Sciences & Chemistry Group