Biogen Inc. v Medeva Plc

The Court held that priority and sufficiency require an enabling disclosure which supports the full scope of the claimed monopoly. A prior application only supplies priority if it enables the skilled person to perform the invention as claimed. Broad claims that cover alternative ways of achieving the same result are invalid if the specification discloses only one way and does not teach a principle that compels use of that way.

Biotechnology patent litigation concerned a European patent claiming recombinant DNA molecules and polypeptides displaying hepatitis B virus (HBV) antigen specificity. Biogen relied upon an earlier UK application (Biogen 1) for priority. Aldous J. at first instance found the patent enabled and entitled to the earlier priority. The Court of Appeal reversed, holding lack of support and obviousness. The EPO had dismissed opposition and found the patent valid. The central issues were (i) inventive step at the 1978 priority date, (ii) whether Biogen 1 provided an enabling disclosure supporting the broad claims, and (iii) the correct date for assessing sufficiency under the Patents Act 1977.

1. Disposition: The House of Lords dismissed the appeal. Lord Hoffmann delivered the leading speech. Lords Goff, Browne-Wilkinson, Mustill and Slynn concurred.
2. Inventive step: The court accepted the four-step approach to obviousness derived from Windsurfing and emphasised that the inventive concept must be formulated with sufficient particularity to include the problem overcome. The inventive contribution was characterised as the idea of trying to express unsequenced eukaryotic DNA in a prokaryotic host rather than the general goal of making HBV antigens. (See paras [10]; [11].)
3. Priority and support (section 5(2)(a)): Following Asahi, the court held that an earlier application supplies priority only if it contains an enabling disclosure enabling the invention as claimed. Biogen 1 did not support the patent claims as broadly framed because it taught one method and did not disclose a general principle that would require others to follow that method. Thus Biogen 1 failed to give the priority date relied upon. (See paras [11]–[13].)
4. Claim scope and technical contribution: A patentee's monopoly must correspond to the technical contribution. Where the same result can be reached by alternative, unrelated methods, a specification enabling one method does not justify claims monopolising all methods. The House applied long-established principles (O'Reilly v. Morse; British United Shoe Machinery) to confine claim breadth to the contribution taught. (See paras [12]; [13].)
5. Sufficiency and date for assessment: The court held that sufficiency under section 72(1)(c) must be judged as at the date of application, not publication, because otherwise an application insufficient at filing could be immunised by later developments. Consequently, on the Judge's facts the specification was insufficient to support the broad claims. (See paras [14].)
6. Practical outcome: Because Biogen conceded obviousness as at the European filing date, loss of priority meant the patent was invalid for obviousness and insufficient to support the breadth of the claims. The Court therefore affirmed the Court of Appeal and dismissed the appeal.

• House of Lords: Appeal dismissed; judgment 31 October 1996 ([1996] UKHL 18).
• Court of Appeal: Allowed appeal, 3 November 1994 (order affirmed by the House).
• High Court (Chancery) - Aldous J.: Held patent valid and entitled to priority (trial findings reversed on appeal).
• European Patent Office: Opposition dismissed by the Technical Board of Appeal on 28 July 1994; EPO had found sufficiency on the question of expression.