Teva UK v Boehringer Ingelheim, High Court

The High Court has ruled in favour of Teva in its application to revoke an inhaler capsule patent held by Boehringer. The patent relates to capsules used in a dry powder inhaler for the delivery of tiotropium bromide in the treatment of asthma or COPD (chronic obstructive pulmonary disease). Tiotropium bromide is the active ingredient in Boehringer’s blockbuster COPD product, Spiriva.

Boehringer, rather defending the patent as granted, put forward eleven new claims. Teva’s opposition to the proposed amendments focused on new Claims 5 and 6. The claimed invention was essentially to tiotropium bromide capsules for inhalation with a reduced moisture content and hence increased stability. Claim 5 was for capsules where the capsule material was HPMC (a cellulose derivative) with a moisture content less than or equal to 5%. Claim 6 was for capsules of the same material with a moisture content of less than 2%.

The conventional material for dry powder inhaler capsules at the priority date of the patent was gelatine. The Court ruled that, in light of the common general knowledge and the teaching of the key prior art document, it would have been obvious for the skilled person to try HPMC, with a high prospect of success. Furthermore, the moisture levels in the amended Claims 5 and 6 were entirely arbitrary and there was no technical justification for their selection. Hence the levels were not inventive.

The Court rejected various arguments put forward by Boehringer as to why the skilled person would have been deterred from using HPMC for the capsule material. Most notably the Court ruled that the purported concern about obtaining regulatory approval for such a capsule was irrelevant in considering obviousness. This principle had been established by earlier case law.

The parties will return to the High Court in December in a separate action concerning the validity of the SPC (supplementary protection certificate) on the basic patent for tiotropium bromide. The SPC is due to expire in March 2016.

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