Mirror, mirror on the wall, what is the first marketing authorization for this enantiomer?

In the recently handed-down judgment of Generics (UK) Ltd v Daiichi Pharmaceutical Co Ltd and another [2008] EWHC 2413 (Pat), Kitchin J has provided an insight on, among other things, how the UK courts deal with the issue of whether the marketing authorization for a racemic product counts as the first marketing authorization as required by Article 3(d) of the SPC Regulation.

In this case, Daiichi Pharmaceutical Co Ltd were the proprietors of European Patent (UK) No. 0206283 and supplementary protection certificate no. SPC/GB97/085. The patent related to the anti-microbial compound levofloxacin, which is the (-) enantiomer of a racemic compound called ofloxacin. The patent for levofloxacin was granted on 27 January 1993. The UK marketing authorization for ofloxacin was granted on 16 March 1990, whereas the marketing authorization for levofloxacin was granted on 6 June 1997.

Generics (UK) sought a declaration of invalidity of (or rectification of the register in respect of) the SPC based on the argument that the UK marketing authorization which were relied upon in support of the application of the SPC were not the first authorizations to place the product on the market as a medicinal product.

Kitchin J disagreed:

• ofloxacin was a recognized anti-microbial agent, known to comprise two enantiomers but, until the EP No. 0206283, the characteristics of the individual enantiomers were not yet known;


• ofloxacin was recognized to be the active ingredient of the medicinal product for which authorizations were sought and granted in 1990. The authorization was to place ofloxacin on the market and not levofloxacin and
  it was known that ofloxacin, levofloxacin and R(+) enantiomer have different properties.

It followed that an authorization to place ofloxacin on the market as a medicinal product cannot be considered as an authorization to place levofloxacin on the market as a medicinal product. Accordingly, the first marketing authorization of levofloxacin was in 1997 and the SPC does fulfill the requirements of Article 3(d) of the SPC Regulation.

Reading this case reminded The SPC Blog of the German Patent Court's rejection in the Fusilade case of the argument raised by the applicant that a racemate and an enantiomer should be considered as separate products for SPC application because they have separate marketing approval. The Court however held that an SPC for an individual enantiomer could potentially be granted if it were the subject of a patent in which it was specifically claimed.