A review of the law on second medical use patent claims:: Have the English Courts gone too far in restricting second medical use claims?

The English Court of Appeal Judgment in Bristol-Myers Squibb Company vs. Baker Norton Pharmaceuticals and Napro Biotherapeutics(2) has restricted the scope of second medical use claims in England to inventions for distinctly different therapeutic applications, thereby excluding inventions for new modes for administration or ones with inherent therapeutically beneficial effects. The Court of Appeal's decision cuts across a body of European and international decisions and limits Mobil(3) to second non-medical uses. In coming to their decision, the Court of Appeal considered in detail the European decisions of Eisai(4) and Mobil but declined to overrule them. How the Court of Appeal's decision will impact on decisions by Courts in other jurisdictions, in particular in Europe, remains to be seen. However, the English Courts have recently considered two further 'second medical use claim' patents: the Court of Appeal in American Home Products vs. Novartis(5) and the High Court in Lilly Icos vs. Pfizer(6). And although these cases do not turn on the fact that they are second medical use claim patents, the Courts do not appear to be deviating from the Court of Appeal decision in Bristol-Myers Squibb. Nevertheless, what is clear, is that the Court of Appeal in Bristol-Myers Squibb omitted to address the public policy issue regarding the extent to which valuable and costly research and development in new therapeutic applications of known medicines, exemplified by the Bristol-Myers Squibb case, should be rewarded by the grant of further patents. This issue is of concern to the pharmaceutical industry and is one that the English Courts will undoubtedly have to clearly address in the future.