Two osteoporosis treatment patents have been found to be invalid following the ruling by the High Court of England and Wales in Hospira UK Ltd & Anor v Novartis AG [2013] EWHC 516 (Pat). The Court found that none of the claims were entitled to the claimed priority and were invalid on the ground of insufficiency owing to the open-ended construction of certain claims specifying dosage and administration intervals.


Novartis was the proprietor of European Patents 1296689 and 1591122 (the second is a divisional of the first patent). The patents, protecting inventions used to treat osteoporosis, related to the administration of zoledronic acid or zoledronate (a salt of the acid) intravenously at intervals of at least six months. The patents claimed priority from two priority documents filed on 20 June 2000 and 9 February 2001. The Claimants sought revocation of the patents for invalidity on the basis that the claims were not entitled to priority and the patents were invalidated by an intervening publication made by Novartis, the claimed inventions were obvious and some of the claims were invalid for insufficiency.


Arnold J held that the patents were invalid on the basis that none of the claims were entitled to the priority asserted. Had they been entitled to the claimed priority, none of the claims would have been obvious over the cited prior art, but several claims would also have been invalid for insufficiency.

One of the principal issues of priority revolved around the fact that Novartis relied on one of its own previous patent application abstracts—part of a piece of prior art referred to throughout the judgment as PD2—for the purposes of priority. The Claimants submitted that the abstract could not be relied on for that purpose, citing Abbott Laboratories v Medinol [2010] EWHC 2865, where it was held, by reference to the European Patent Convention, that an abstract in a European patent application did not form part of that application in relation to an added matter issue. The Court held that the same reasoning should not be applied in this case, because PD2 was a United States patent application. Despite this, it found that PD2 does not disclose that intravenous zoledronate at intervals of at least six months is effective to treat osteoporosis because, although the information contained in the abstract links zoledronate, osteoporosis and six monthly administration, it does not mention intravenous administration.

The Claimants pointed out that some of the claims of the patents were open-ended in that they either had no upper limit to the period between administrations, or they had no upper or lower limit to the doses, or both. Relying on the test quoted in Novartis AG v Johnson & Johnson Medical Ltd [2010] EWCA Civ 1039, [2011] ECC 10, the Claimants argued that these claims were invalid for insufficiency because the skilled person could not readily perform the invention over the whole area claimed without undue burden and without needing inventive skill.

The Court determined that the open-ended claims should only be interpreted as extending to any dose or dosage interval that was effective in practice. Even so, in this case, the Court found that the potential scope of the open-ended claims was wide, requiring the skilled person to undertake a comprehensive series of clinical tests to find out what doses and dosage intervals were efficacious. It followed that the claims were not enabled across their breadth and therefore these claims were invalid for insufficiency.


Although it was held that the abstract of a US patent application could be relied on in establishing priority, it is perhaps not surprising that the abstract did not overcome the invalidity arguments, as an abstract does not usually contain information that is not already in the body of the main text.