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DE – nullification of EP 1 379 220 (inhalation capsules)

21 Jan 2016

Cinfa v Boehringer-Ingelheim (“BI”), Federal Court of Justice, Germany, 12 January 2016, Case No. X ZR 38/14, with thanks to Matthias Sonntag, Gleiss Lutz

In nullity case Cinfa v Boehringer-Ingelheim (“BI”) – X ZR 38/14 – regarding European Patent 1 379 220 (“EP’220”), the German Federal Court of Justice (Bundesgerichtshof, “FCJ”) lifted the first instance judgment of the Federal Patent Court (Bundespatentgericht, “FPC”) which upheld the patent in an amended form (docket number 3 Ni 10/12) and declared the German part of EP’220 invalid in its entirety. The judgment which has been orally announced at the end of the trial on January 12, 2016 is not yet available in written form.

BI defended the patent only on the basis of a restricted main claim having as subject matter an inhalation capsule comprising as an inhalation powder a mixture of tiotropium and a physiologically acceptable excipient, characterized in that the capsule material has a reduced TEWS or halogen drier moisture content of less than 15%, and the capsule material is selected from the group consisting of gelatin, hydroxypropylmethylcellulose (“HPMC”), hydroxypropylcellulose, methylcellulose, hydroxymethylcellulose and hydroxyethylcellulose, wherein the gelatin is present in a mixture with further additives from the group consisting of polyethylene glycol (“PEG”), preferably PEG 3350, glycerol, sorbitol, propylene glycol, PEO-PPO-blockcopolymers and further polyalcohols and polyethers.

The FPC held in its first instance ruling that this subject matter was not based on inventive activity but maintained EP’220 in an even more limited version which specified the inhalation capsule further in that (i) the inhalation powder is limited to a mixture of tiotropium and lactose, (ii) the capsule material is selected from the group consisting of HPMC and gelatin, wherein the gelatin is present in a mixture with 1 to 10% of further additives from the group consisting of PEG, and (iii) the lactose consists of a mixture of coarse lactose with an average particle size of 15 to 90 µm and fine lactose with a particle size of 1 to 9 µm, wherein the amount of fine lactose is 5 to 10%, based on the overall lactose amount.

Relevant observations made by the FCJ during the appeal trial are summarized below:

As regards BI’s main defense, the FCJ acknowledged that while capsules for inhalation devices containing tiotropium bromide in a mixture with a physiologically acceptable excipient have been known (e.g. from Maesen et al., Eur.Respir. J., 1995, 8, 1506-1513), the respective prior art did not specify the material of those capsules. However, as regards HPMC as capsule-material, the FCJ’s pointed to Ogura et al., Pharm. Tech. Europe, 1998, 10(11), 32-42, which recommended the use of HPMC capsules as an alternative to gelatin capsules also with respect to inhalation powders. With respect to gelatin in a mixture with PEG, the FCJ pointed to JP 2000-143502 which disclosed new advantageous capsules (such as hard gelatin capsules containing PEG as claimed by EP’220) for inhalable formulations that can be used for all kinds of inhalation powder or active agent. In its introductory remarks, the FCJ suggested that the disclosure of these prior art references provided sufficient motivation for a skilled person to provide the known inhalation powder comprising tiotropium bromide and excipient by means of a capsule made of the material claimed by EP’220.

With respect to BI’s auxiliary defense based on the limited version of EP’220 maintained by the first instance decision under appeal, the FCJ suggested that the claimed mixture of different types of lactose had been known in the art as being advantageous for inhalation powders also containing tiotropium bromide. The FCJ suggested that it would appear to be obvious for the skilled person to combine the known advantages associated with the use of an inhalation powder comprising the active agent and as excipient coarse and fine lactose on the one hand and, on the other hand, the known advantages of a capsule-material as disclosed in Ogura et al., Pharm. Tech. Europe, 1998, 10(11), 32-42 or in JP 2000-143502. Both features, the mixture of lactose and the material of the capsule, could be regarded as common measures in the art in connection with inhalation formulations, e.g., to improve the (aerodynamic) properties of the powder and the properties of the capsule, respectively.

BI and Cinfa provided extensive arguments during the hearing. At the end of the trial, the FCJ declared the German part of EP’220 invalid in its entirety.