The Patents Court has decided that Boehringer’s EP (UK) 1 379 220 relating to capsules to be used in a dry powder inhaler used to deliver tiotropium bromide to the lung of a patient suffering from chronic obstructive pulmonary disease (COPD) or asthma is invalid following a challenge by Teva. Boehringer did not seek to defend the validity of the original claims but proposed 11 new claims. The Court, however, found amended claims 5 and 6 invalid on the grounds of lack of inventive step in the light of the prior art and common general knowledge and that certain integers in the claims were arbitrary. Amended claim 5 related to the capsule material being a cellulose derivative material (HMPC) with a moisture content of less than or equal to 5%; amended claim 6 related to the same material with a moisture content of less than 2%.
The Judge, Morgan J, concluded that, in the light of the prior art, it was obvious at the priority date to try using HPMC as the capsule material instead of the conventional material, gelatine, with a high prospect of success. In doing so, he rejected Boehringer’s argument that commercial considerations such as regulatory difficulties should be taken into account, saying he was bound by the decision in Re Richardson-Vick’s Patent which rejected the argument that, if an invention is technically obvious, a likely failure to obtain regulatory approval would make it not obvious to try. In doing so, he did note Birss J’s comments in Teva v Leo who had suggested that uncertainty surrounding the regulatory process was a potential factor to take into account, albeit its significance would vary and was likely to be outweighed by technical issues.
Morgan J also agreed with Teva that the figures for the moisture levels in amended claims 5 and 6 were arbitrary and were chosen without a technical justification.
A separate dispute between the parties over an SPC (due to expire in March 2016) related to the patent for tiotropium bromide (sold under the brand name Spiriva, an extremely successful product for Boehringer), will be heard by the Court in December 2015.