In Generics (UK) Ltd v Daiichi Pharmaceutical Co Ltd [2009] EWCA Civ 646 (2 July 2009), the Court of Appeal has upheld a decision of the Patents Court confirming the validity of a patent and accompanying supplementary protection certificate to an enantiomer of a known racemate.

At first instance, Mr Justice Kitchin concluded that the patent was valid over the cited prior art, and that the SPC was validly granted. He concluded that the patent was inventive over common general knowledge, as knowledge of racemate did not mean that use of only one of the constituent enantiomers was obvious, particularly where that individual enantiomer showed greater efficacy than the racemate, of which the skilled addressee would not have been aware. He also concluded that the skilled addressee of the patent reading the cited prior art would have considered it worthwhile exploring whether the racemate, ofloxacin could be resolved into its constituent enantiomers, and it would not have been obvious that this would be a fruitful exercise. On the SPC, he held that a marketing authorisation for ofloxacin could not be considered as authorisation to market levofloxacin, its negative enantiomer. Since it had required invention to produce levofloxacin, and marketing authorisation was not granted for levofloxacin until 11 years after the patent had been granted, it was just for the defendant to be granted an SPC in respect of that delay. The claimant appealed.


The Court of Appeal upheld the judge’s decision in full. It held that Kitchin J’s reasoning on the cited prior art was a perfect example of a judge carrying out the balancing task of forming an overall value judgment, and so could not be faulted. As Lord Justice Jacob giving the lead judgment put it: “Only a curmudgeon would say that there is no invention here”.

The Court of Appeal also agreed with the approach taken by the judge on the SPC. This case was one in which the underlying research had led to what was effectively a new medicine. The claimant’s argument that ofloxacin should be regarded as no more than levofloxacin with an impurity was also rejected. Neither patent law nor the law controlling the marketing of medicines regarded it as such, and there was no reason why the law on SPCs should be different. The claimant sought to rely on case law from numerous non-EU jurisdictions in support of this contention, which was rejected as being concerned with different statutory language, views of the facts and policies.