In a judgment handed down in October of this year, the Patents Court (Mr Justice Floyd) upheld EP (UK) 0,454,436 (the “Patent”) which is owned by Eli Lilly and which protects the schizophrenia drug olanzapine. Olanzapine is one of Lilly’s blockbuster drugs. Dr Reddy’s Laboratories (“Dr Reddy’s”) challenged all of the claims of the Patent on the grounds of anticipation and obviousness and some of the claims of the Patent on the ground of insufficiency.  

The main anticipation attack on the patent was based on the disclosure in an earlier patent application filed by Lilly back in 1974 of a class of thieno-benzodiazepines (the “235 Application”). The general formula extended to more than 1019 compounds one of which was olanzapine. Although the 235 Application specifically disclosed some closely related compounds to olanzapine, it did not specifically disclose olanzapine itself.  

The judge first had to decide whether the disclosure in the 235 Application was an anticipation of the later claim for olanzapine and then secondly if so, whether the later claim to olanzapine was nevertheless valid by virtue of being a selection invention. The judge first addressed the general law of novelty. He reviewed the decision of the House of Lords in Synthon’s Patent ([2006] RPC 10). In that decision, the House of Lords cited with approval the wellknown passages from the speech of Lord Westbury LC in Hills v Evans and the Court of Appeal judgment in General Tire and Rubber Co v Firestone Tyre and Rubber Co Ltd. In the light of those the judge held that “… a generic disclosure will not normally take away the novelty of a subsequent claim to a member of the class.”  

The judge then focused on the particular issue in the case namely the effect of the prior disclosure of a chemical class formula or “Markush” formula. He then went on to consider the law developed by the EPO on this issue.  

He noted that the case law envisaged two ways in which a novel selection could be made. First, when the selected compound falls within territory marked out in the state of the art but is “unmentioned”. Second, when the selected compound is arrived at by choosing a combination of starting materials from “two lists of some length”.  

The judge concluded that as a general matter, a prior disclosure would not take away the novelty of a claim to a specific compound unless the compound was disclosed in “individualised form” and that a general formula with multiple substituents chosen from lists of some length would not normally take away the novelty of a subsequent claim to an individual compound.  

He then went on to consider the law of selection patents as it had been developed in the UK under the 1949 Act and in particular the IG Farbenindustrie’s Patent case.  

The judge concluded:  

“(i) In relation to lack of novelty, it is doubtful in the light of the EPO jurisprudence whether a newly discovered effect complying with Maugham J’s principles could overcome a finding that a compound was specifically disclosed in a prior document.  

(ii) Whether or not that is so, provided there is novelty on conventional grounds, obviousness is to be decided according to ordinary principles.  

(iii)The existence of an advantage possessed by the selected compound will be relevant to the overall assessment of obviousness, but is not an essential pre-requisite.  

(iv)Compliance with Maugham J’s principles in I. G. Farbenindustrie’s Patent is equally not an essential requirement for inventive step to be found.”  

His conclusions on the applicability of that law in the light of the EPO jurisprudence on the issue were obiter as he held that the disclosure of the chemical class formula in the 235 Application did not take away the novelty of the subsequent claim to olanzapine.  

He also held that the claim to olanzapine did not lack novelty over the other two cited documents.  

As regards inventive step, Dr Reddy’s relied on four pieces of prior art including the 235 Application as well two papers authored by Dr Chakrabarti, the leader of the anti-psychotic drug team at Lilly. The judge applied the test for obviousness set out in Pozzoli v BMDO ([2007] FSR 37) and Lundbeck v Generics ([2008] EWCA Civ 311). He found that on the evidence, the invention namely olanzapine was not obvious over any of the cited prior art as it would not have been obvious to have synthesised and tested olanzapine on the basis of the information disclosed in each of those pieces of prior art.  

He went on to say that in the circumstances of the case, the evidence of commercial success was unhelpful in deciding the question of obviousness. Although he accepted that in some circumstances evidence of commercial success could be a relevant secondary indication of non-obviousness, where the product is the subject of anterior patent protection then commercial success arguments “are more or less doomed to failure”.  

Finally, dealing with the allegation of insufficiency, the judge reviewed the Court of Appeal’s recent decision in Lundbeck. Dr Reddy’s arguments on sufficiency were to a large extent tied into their arguments on selection inventions. As noted above, the judge determined the claim to be novel in any event.  

The case is of considerable interest for several reasons not least the Judge’s approval of the approach taken by the EPO to the issue of generic disclosures as well as his comments on the law on selection inventions. It is understood that Dr Reddy’s has been granted leave to appeal. It is perhaps also of interest to note that in Germany the decision of the German Patents Court revoking the patent inter alia on the ground of lack of novelty has recently been overturned by the German Supreme Court who found that the patent was valid i.e., novel, inventive and sufficient.