Pfizer pregabalin patent held invalid by the UK Supreme Court

The Supreme Court has handed down a decision in the litigation of Warner-Lambert versus Actavis and Mylan. 

With implications particularly in the chemical, medical and life sciences fields, this decision highlights the importance of including in a patent application at the time of filing, enough information (e.g. experimental data and scientific basis) to make it plausible that the invention works.

Background

Warner-Lambert, a company in the Pfizer group, was the proprietor of a European patent which sought to protect the use of pregabalin, a drug which it had developed, and marketed as ‘Lyrica’, in the treatment of neuropathic pain.  The patent contained ‘second medical use’ claims, which are claims directed to a specific therapeutic use of a drug (where another medical use of the same drug is known).  The claims of most relevance were claim 1, directed to the use of pregabalin for the treatment of all types of pain; and claim 3, directed to the use of pregabalin for the treatment of neuropathic pain.  A decisive factor in this case was that the patent application at the time of filing included only experimental data demonstrating treatment of inflammatory pain.

Mylan and Actavis claimed for revocation of the patent on the grounds of lack of inventive step and insufficiency, and Warner-Lambert claimed against Actavis for infringement of claims 1 and 3. 

The Patents Court at first instance and the Court of Appeal on appeal held that claims 1 and 3 were invalid on the ground of insufficiency. 

This Decision

The Supreme Court judges decided that whilst the information in the patent made it plausible that pregabalin could be used to treat some types of pain, it did not make it plausible that pregabalin could be used to treat all kinds of pain, so claim 1 to treatment of pain generally was insufficient.  Similarly, the Supreme Court held that from the information in the patent it was not plausible that the drug would treat neuropathic pain in particular, so claim 3 to treatment of neuropathic pain was insufficient.  Hence, the Supreme Court upheld the previous decisions of the Patents Court and Court of Appeal that claims 1 and 3 – those of relevance to Actavis’ activities – were invalid as insufficiently disclosed.

Practical Points

This decision has particular implications in the chemical, medical and life-sciences fields, confirming that the relatively new test of ‘plausibility’ is required, and that evidence the invention works must be present on filing and must be commensurate with the scope of protection sought.  It is paramount that information in a patent application at the time of filing makes it plausible that the invention actually works, or else the patent application (or eventual patent) may be refused or revoked for insufficiency.  Plausibility has to derive from the patent application at the time of filing, and cannot be gleaned though later-filed evidence. 

One of the most challenging aspects in the pharmaceutical realm is when to file a patent application to an invention.  On one hand it must be filed before others do the same or the invention is disclosed – favouring a relatively quick filing strategy – and on the other hand it must be filed with enough information to render the invention sufficiently disclosed – favouring a relatively slower filing strategy.  At Wilson Gunn we can help to balance these considerations and file your application at the right time. 

We have attorneys with expertise in the chemical, medical and life sciences fields.  If your business depends on technology in any of those fields, we can help to secure the intellectual property protection you need, so that you can maintain exclusivity in the market.  We can also help you to navigate through the intellectual property landscape and reduce your risk exposure, enabling your business to thrive and prosper. 

Please contact one of our attorneys if you have any questions.


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