A recent decision in the United Kingdom suggests that the strict priority approach applied in the European Patent Office (EPO) Boards of Appeal will also be enforced in that jurisdiction against patentees relying on the filing dates of earlier applications. The Court of Appeal in Hospira UK Generics Ltd. v. Novartis AG,  EWCA Civ. 1663 (Dec. 19, 2013), held that a claim directed to use of a specific compound to treat osteoporosis at a certain dosage was not entitled to the earlier priority date of a U.S. patent application, notwithstanding that all the claim elements appear to be disclosed in the U.S. application, when read as a whole.
UK Priority Law
Applicants may benefit from the filing date of a foreign application under the terms of the Paris Convention for the Protection of Industrial Property. In the United Kingdom, Section 5 of the Patents Act 1977 (PA 1977) provides for reliance on an earlier priority date. The corresponding provision of the European Patent Convention (EPC) is Article 87(1). While Section 5 PA 1977 uses different language from Article 87 EPC, the Court of Appeal has held that the UK statute and the EPC article mean the same thing.1
Article 87(1) EPC governs priority in this context, stating that
[a]ny person who has duly filed, in or for . . . any State party to the ParisConvention . . . , an application for a patent . . . shall enjoy, for the purpose of filing a European patent application in respect of the same invention, a right of priority during a period of twelve months from the date of filing of the first application (emphases added).
Thus, under Article 87(1) EPC, an applicant’s claim will benefit from a right of priority of an earlier application if for the “same invention.” See id. Importantly, this has been interpreted by the Enlarged Board in G02/98 to mean that priority is effective “only if the skilled person can derive the subject-matter of the claim directly and unambiguously, using common general knowledge, from the previous application as a whole.”2 This standard requires, at minimum, that all elements from the claim be disclosed, explicitly or implicitly, in the earlier application. See id.
The UK courts have also recognized the significance of G02/98, finding its approach not inconsistent with leading UK decisional law on priority.3 On the one hand, in Pharmacia Corp. v. Merck & Co., R.P.C. 41, priority was lost by narrowing down from the disclosure of the priority document so that the invention could not be directly and unambiguously derived from it. On the other hand, in Beloit Technologies Inc. v. Valmet Paper Machinery Inc.,  R.P.C. 7005, priority was lost by overgeneralizing from the disclosure of the priority document.4
The patent-at-issue in Hospira UK Generics was European Patent (UK) 1 296 689, belonging to Novartis.  EWCA Civ. 1663, ¶ 1. The Novartis patent related to the use of a particular member of the bisphosphonate class of drugs. Id. Specifically, Novartis’s claim 7 claimed the use of a zoledronate medicine for the treatment of osteoporosis and adapted for intravenous administration in a unit dosage form which comprises from about 2 to 10 mg of zoledronate, administered about once a year. Id. Claim 7 covered Novartis’s commercial drug product ACLASTA, a successful, once-yearly infusion product. Id. ¶ 3. Claim 7 was argued to have the priority date of an earlier U.S. application filed June 20, 2000. Id. ¶ 2. The main issue with respect to this claim was whether the disclosure in the U.S. application contained the subject matter, because, if not, the parties agreed that an intervening publication would be invalidating. Id. ¶ 3.
The High Court held that, although the elements of claim 7 were disclosed in the U.S. application, “there was nothing to link the dosage sizes and intervals there claimed with the other features of the claims, such as treatment of osteoporosis and intravenous administration.” Id. ¶ 22. Mr. Justice Arnold explained that
[t]he nearest one gets is the abstract, which links zoledronate, osteoporosis and six monthly administration, but does not mention intravenous administration . . . . As for Example 5, this is limited to the intravenous administration of particular doses of zoledronate to post-menopausal osteoporosis patients six monthly and yearly . . . .”5
Since the court found that there was no linkage of the elements in the disclosure, Novartis was deemed to lack priority for claim 7 and the patent was invalidated in the first instance.6
Court of Appeal Decision
On appeal, Novartis argued that the High Court erred by reading the relevant passages in isolation. Had the High Court properly read the disclosure as a whole, Novartis contended, it would have credited, inter alia, the “2-10 mg once a year” passage7 as containing a clear and unambiguous disclosure for the claim. Id. ¶ 23. Although the critical “2-10 mg once a year” passage does not expressly mention osteoporosis or a particular mode of administration, Novartis explained that treatment of osteoporosis was the very focus of the U.S. application. Id. Further, according to Novartis, intravenous administration appears throughout the disclosure as a principle route taught. Id.
For a unanimous court, however, Lord Justice Floyd succinctly stated “that the problem for Novartis in seeking to establish that claim 7 is entitled to priority from [the U.S. application] is that thedisclosure . . . is either too general or too specific.” Id. ¶ 32. When focused on the priority disclosure for zoledronate, the “‘2-10 mg once a year’ passage tells the skilled reader nothing about the dosage range for any particular method of administration . . . [and] does not tell the reader about dosage range for any particular condition, such as osteoporosis,” meaning that it was too general to support priority. Id. When focused on the priority disclosure for mode of administration, “Example 5, on the other hand, is specific[,] . . . teach[ing] that 4 mg, once a year, administered intravenously to patients with post-menopausal osteoporosis is effective, but nothing about what other doses could be used at that dosage interval.” Id.
The Court of Appeal acknowledged Novartis was correct that intravenous administration is one of the preferred methods of administrations in the disclosure and that osteoporosis is highlighted in the disclosure as one of the conditions targeted. Id. ¶ 33. But the Court of Appeal rejected the notion that the “2-10 mg once a year” passage must be read to teach that no matter how one administers zoledronate, and no matter what condition one administers it for, 2-10 mg is always suitable dosage range. Id. “To put it another way,” if Novartis’s theory were adopted, “it would be read as saying that this particular dosage range can be used independently of the condition being treated and independently of the method of administration.” Id. ¶ 35. Instead, Lord Justice Floyd explained that a skilled person would read the “2-10 mg once a year” passage quite differently, “namely that, depending on the method of administration and the condition being treated, some doses within this range may be suitable.” Id. ¶¶ 35-36.
Supporting this conclusion, the Court of Appeal cited the following: (1) the specification elsewhere expressly states that the dosage is dependent on method of administration and condition;(2) the skilled person knows from common general knowledge that dosage is critically dependent on method of administration and condition; (3) the fact that other dosage ranges are given in the patent could not be taken as saying that they were suitable for every condition and every means of administration; and (4) the expert testimony that a 2-10 mg would be “in play” for intravenous administration was “well short” of what is required, such that “nothing in the expert evidence . . . displace[d] the view that there is no disclosure in [the U.S. priority application] of using 2-10 mg zoledronate once a year by intravenous administration to treat osteoporosis.” Id. ¶¶ 36-40.
Accordingly, claim 7 could not rely on the disclosure of the U.S. application and its earlier priority date. The trial court’s invalidity judgment was approved and the appeal was dismissed, with Lord Justice Patten and Lord Justice Tomlinson in accord. Id. ¶¶ 42-44.
In fact, all elements of claim 7 were in some fashion disclosed in the U.S. priority application, as the Court of Appeal acknowledged. See id. ¶ 33. But these disparate elements were deemed insufficiently linked to the claimed invention to find it directly and unambiguously disclosed to a person of skill. Novartis’s main contention that “reading the document as a whole, one sees a disclosure of the whole package of claim 7,” was scarcely addressed and did not persuade the court. Id. (emphasis added). The resulting strict approach to priority means that U.S. practitioners need to be aware in preparing priority filings that will be relied on later at the EPO or in EPO member states. A clear linking statement for all claimed subject matter is now advisable to avoid losing priority.