Where there’s a will, there’s a way for new medical use patents

Partner and patent attorney at intellectual property firm, Withers & Rogers, Dr Nicholas Jones, discusses why drug companies should continue to pursue new medical patents in the future, despite recent examples of legal disputes.  

News that Pfizer has lost its final appeal in the battle to maintain patent protection for the second medical use of one of its best-selling drugs, means innovators could find it more difficult to secure and enforce exclusive rights to market such treatments in the future. Whilst this is a set-back, drug companies should not be put off from pursuing new medical use patents in the future.

Following a long-standing legal battle, the Supreme Court has concluded that a new medical use patent secured by Warner-Lambert (now owned by Pfizer) at the European Patent Office in 2003, is invalid on the grounds that insufficient data was provided to support its efficacy. The ruling upholds earlier decisions at the UK High Court and Court of Appeal, which were brought following a legal challenge by Actavis and other generics producers in 2015.  In reaching its decision, the judges at the Supreme Court also recommended the introduction of some steps that could make it easier for generic companies to sidestep infringement actions in the future.

The drug at the centre of this legal battle is the blockbuster drug, Lyrica, which is widely used to treat patients with epilepsy. Whilst marketing it for this purpose, Pfizer discovered that the drug is also effective in the treatment of neuropathic pain. However, the Court of Appeal decided that the data submitted with the patent was only sufficient to support its use in the treatment of peripheral neuropathic pain.  In fact, some of the judges went further, deciding that the data didn’t support any kind of neuropathic pain.

Building on previous case law, the Supreme Court’s decision is a significant victory for generics producers. However, the judges were unable to reach agreement on the issue of ‘plausibility’. This means that further case law may be required to determine whether generics companies will be successful in challenging second medical use patents on the grounds that insufficient data was provided to support their functionality at the time of filing.

Whilst it wasn’t a binding part of the ruling, the judges also couldn’t agree on the matter of what would constitute infringement of a second medical use patent by a generics company.

Actavis has been marketing Lecaent, its own version of Lyrica, with a so-called ‘skinny label’, i.e. an information sheet noting that the drug can be used for epilepsy or general anxiety disorder, but not mentioning neuropathic pain.  Despite doing this, due to prescribing practices in the UK, it was inevitable that the drug would also be sold for the purposes of treating neuropathic pain.  To try to minimise this practice, the High Court took the unprecedented step of granting an order mandating the NHS to issue guidance to doctors and pharmacists that Lyrica must be prescribed for the treatment of neuropathic pain using its brand name, and not using its generic name ‘pregabalin’.  In the leading judgement for the Supreme Court however, Lord Sumption appeared to disapprove of this intervention noting that it is “by no means clear that it will always be appropriate to meet problems arising in relation to second medical use patents by guidance of this kind”, which suggests similar orders are unlikely in the future.

In relation to infringement more generally, the judges disagreed over the importance of the intention of the alleged infringer.  Some of the judges proposed the use of an ‘outward presentation’ test, based on the content of any product labelling or other printed information, which, to avoid infringement, should only refer to the patented uses of the drug. However, the Supreme Court’s split opinion on this matter means generics companies will still need to be careful about how their products are marketed and promoted by their sales force, to avoid potential infringement actions.

Overall, the ruling will be a disappointment for Pfizer and other drug companies that have invested large sums of money to find new medical uses of existing drugs and bring them to market. However, crucially, it may still be possible to bring an infringement action against a generic rival if their intention is unclear. Drug companies are also likely to take a more strategic approach when pursuing second medical use patents in the future.