Novartis AG & Ors v Focus Pharmaceuticals Ltd & Ors

A patent claim directed to rivastigmine administered transdermally at a specified starting dose contained added matter where the application presented the invention as lying in particular patch structures and pharmacokinetic ranges, rather than in selecting that starting dose. Extracting the dose from a specific example and applying it to other patch structures was an impermissible intermediate generalisation. The claim was also obvious where the skilled team, motivated to provide once-daily treatment, would have been led by the prior art and common general knowledge to trial that starting dose. A claim is not insufficient merely because it could be implemented badly if the skilled person would not choose that implementation. Ambiguity was not established where common general knowledge enabled appropriate comparative measurements and statistical analysis.

Novartis claimed infringement of a patent for administering rivastigmine by a transdermal therapeutic system for treating dementia or Alzheimer’s disease. Focus, Actavis and Teva denied infringement and counterclaimed for revocation on added matter, obviousness and insufficiency.

The claim was construed as covering rivastigmine administered by any transdermal system delivering the starting dose released by a specified 5 cm² reference patch, rather than being limited to that patch’s structure and composition. The central issues were whether that construction added matter, whether the claimed starting dose was obvious over US Patent No 6,335,031, and whether the claim was insufficient. The court also considered infringement if the patent were valid.

1. Construction. The claim covered administration by a transdermal therapeutic system delivering a starting dose equivalent to that released by the specified 5 cm² reference patch. “Starting dose” meant the released dose administered during the first period of treatment, not the loaded dose or the dose measured by AUC24h. AUC24h measured bioavailability rather than dose.
2. Added matter. The application disclosed principally a three-layer transdermal system and systems producing specified pharmacokinetic ranges. It did not directly and unambiguously disclose that the invention lay in selecting the particular starting dose delivered by the reference patch, or that the dose could be delivered by systems with different structures and compositions. The claim therefore extracted the dose from its context and amounted to an impermissible intermediate generalisation. The patent was invalid for added matter.
3. Obviousness. The structured approach in Pozzoli v BDMO SA and the authorities there discussed was applied. The skilled team would have been motivated to develop once-daily rivastigmine treatment, would have considered transdermal delivery suitable, and would have matched exposure to an existing oral formulation. US031 disclosed the relevant patch structure and composition and invited routine bioavailability testing. In light of the expected smoother plasma profile, the skilled team would have had sufficient expectation of success to trial the reference starting dose in a small clinical study. The claimed invention lacked an inventive step.
4. Insufficiency. Excessive breadth was not established because the skilled person would not ordinarily choose a badly implemented burst-release formulation. Nor was the claim ambiguous: comparative repeat measurements and normal statistical methods enabled the skilled team to determine whether another patch delivered the same dose.
5. Infringement and disposition. The defendants’ patches would have fallen within the claim because they were generic versions of the reference patches and were intended to be used with the same starting dose. The patent was invalid for added matter and lack of inventive step. The insufficiency challenge failed. If valid, the patent would have been infringed.