This is the second judgment handed down in 2015 involving Actavis and Eli Lilly. We previously wrote about the Court of Appeal’s June 2015 decision in Actavis UK Ltd v Eli Lilly and Company [2015] EWCA Civ 555 (see our October 2015 edition of On The Pulse). In that case, which related to Lilly’s patent for the use of pemetrexed disodium, the Court of Appeal allowed Lilly’s appeal and refused to grant Actavis the declarations of non-infringement it sought regarding the UK, France, Italy and Spain as it found that Actavis had indirectly infringed Lilly’s patent.

The latest decision handed down on 16 November 2015, being the first from newly-appointed Carr J, concerned a different set of facts. In this case, Actavis sought the revocation of another patent owned by Lilly (EP (UK) 721 777), which included a Swiss form second medical use type claim for the use of tomoxetine (also known as atomoxetine) in the manufacture of a medicament for treating ADHD (attention deficit/hyperactivity disorder). Lilly has sold atomoxetine in the UK for ADHD treatment under the name “Strattera” since 2004 and holds a Supplementary Protection Certificate, providing protection until 26 May 2019. Actavis intended to clear the way for it to launch a generic atomoxetine product before the SPC’s expiry.

Actavis’ challenge was based on there being a lack of: inventive step (based on two pieces of prior art); plausibility leading to insufficiency or obviousness; and entitlement to priority due to the lack of plausibility. Ultimately, Carr J upheld Lilly’s patent and its counterclaim for threatened infringement, the latter based on the admission that Actavis made in its pleadings regarding its intention to launch a generic product.

Of most interest are Carr J’s comments on the reach of the plausibility threshold applicable to insufficiency. Carr J held that the standard for assessing plausibility regarding insufficiency differs from the assessment of expectation of success regarding obviousness.

Carr J noted the limitations of the “obvious to try” test. Adopting a commendably practical approach, he explained that, in particular, in the context of pharmaceutical and biotechnology inventions, policy considerations underlying plausibility for sufficiency differ from those underlying fair expectation of success for obviousness. In this regard, Carr J approvingly referred to dicta to that effect of Kitchin LJ in Medimmune v Novartis [2012] EWCA Civ 1234.

He held that for something to be obvious, it must be more than simply “obvious to try”. Otherwise, that lower threshold would deny patent protection to many research programmes which often have uncertain outcomes, consequently significantly deterring many research activities. The requisite threshold for obviousness is that an activity has a “fair expectation of success”.  Meanwhile, plausibility for sufficiency functions to exclude speculative patents based on mere assertion where there is no real reason to suppose the assertion to be true. Accordingly, plausibility is a lower threshold and is met by a disclosure that is “credible”. Carr J also emphasised that plausibility is only a threshold test; a plausible invention may nevertheless be insufficient.

On the facts, the Court held that the claims were not obvious based on the cited prior art and that, even if it were obvious to try atomoxetine for the treatment of ADHD, the skilled team would not have had a fair expectation that atomoxetine would be discernibly effective in treating ADHD. The Court also held that the skilled team would find the patent’s invention to be plausible and Actavis’ insufficiency-targeted attack failed. Actavis argued, inter alia, that the patent contained no more than a bald assertion that atomoxetine was effective and safe for the treatment of ADHD. In fact, whilst the patent disclosed how atomoxetine worked to treat ADHD, it did not contain any data supporting the safety/efficacy statements that it made. Carr J stated that there is no requirement for patents to contain data or experimental proof to support their claims and that the reference to experimental data in Salk (T 609/12) was only by way of example. Moreover, the patent’s citation of a relevant paper, which contained a discussion of the mechanism of atomoxetine’s activity, contributed towards establishing plausibility.

The decision is a useful reinforcement of the demarcation between plausibility and obviousness and, so, bound to be welcomed by patentees. On 14 December 2015, Carr J granted Actavis permission to appeal his judgment. Practitioners and advisers alike will no doubt be watching this space for the next instalment in the ongoing Actavis/Lilly judicial saga.