Biogen Inc v. Medeva Plc

Factual and Procedural Background

Company A obtained a European patent concerning recombinant DNA molecules capable of expressing hepatitis B virus (HBV) antigens. The underlying laboratory work had been carried out in 1978 by Professor Murray, whose experiments inserted large, un-sequenced fragments of HBV DNA into a bacterial plasmid (pBR322) and achieved expression of HBV antigens in E. coli. On 22 December 1978 Company A filed a United Kingdom application (“Application 1”), and on 21 December 1979 filed the European application that matured into the disputed patent.

In 1992 Company A sued Company B for infringement, whereupon Company B counter-claimed for revocation on four principal grounds: lack of inventive step, lack of entitlement to the 1978 priority date, absence of a patentable “invention,” and insufficiency of disclosure. Judge Aldous upheld the patent and found infringement. The Court of Appeal (Judge Nourse, Judge Peter Gibson and Judge Hobhouse) reversed that decision in full, holding the patent invalid and not infringed. Company A appealed to the House of Lords; the appeal was heard over several days in April and May 1996. The House of Lords (Judge Hoffmann giving the principal opinion, concurred in by Judge Browne-Wilkinson, Judge Mustill, Judge Slynn and Judge Nolan) dismissed the appeal.

Legal Issues Presented

1. Whether the invention claimed in the patent involved an inventive step as at the relevant priority date (Patents Act 1977, s.3).
2. Whether Application 1 “supported” the claims within the meaning of s.5(2)(a), thereby entitling the patent to the earlier (1978) priority date.
3. Whether the claims were so broad that they lacked sufficiency and were liable to revocation under s.72(1)(c).
4. Whether, even if the preceding issues were resolved in Company A’s favour, the claims constituted a patentable “invention” under s.1(1).

Arguments of the Parties

Appellant’s (Company A) Arguments

• The inventive concept was Professor Murray’s decision to express HBV antigens in a host cell using recombinant DNA; that concept was not obvious in 1978.
• Application 1 enabled the skilled person to produce both HBcAg and HBsAg, and therefore “supported” the broader claims now in issue.
• Because the patent was entitled to the 1978 priority date, the later state of the art could not be used to render the claims obvious.
• The specification was sufficient: a single enabled embodiment (HBcAg in E. coli) was all that European law required.

Respondent’s (Company B) Arguments

• The true inventive concept was merely “using known recombinant techniques to pursue an obvious goal,” which would have been routine for the skilled person by 1978.
• Application 1 did not enable or describe the invention across its full breadth; therefore the patent could not claim the 1978 priority date.
• Without that priority date, the claims were obvious in light of subsequent sequencing of the HBV genome and improved host systems.
• The description was insufficient because it disclosed only one specific route (large genomic fragments in bacteria) yet claimed every recombinant route.

Table of Precedents Cited

Court’s Reasoning and Analysis

Judge Hoffmann began by isolating the “inventive concept.” He rejected the trial judge’s broad formulation (“deciding to express HBV antigens”) and held that the true concept was narrower: attempting to express un-sequenced eukaryotic DNA in a prokaryotic host by selecting restriction enzymes that produced large DNA fragments.

Proceeding through the Windsurfing framework, the House accepted—without deciding—that this narrower concept was not obvious in 1978. The pivotal issue therefore became entitlement to the 1978 priority date.

Under s.5(2)(a) a claim enjoys that date only if the earlier application “supports” it, which, per Asahi, requires an enabling disclosure. The House held that Application 1 did not enable the invention to the full extent of the monopoly claimed:

• The 1978 disclosure taught only one specific route (large genomic fragments in bacteria) and did not reveal any general principle applicable to all recombinant methods.
• Later, better-informed routes—using sequence data to pick precise restriction sites, or employing mammalian host cells—could be practised without relying on Professor Murray’s teaching.
• Allowing Company A to claim “any recombinant DNA molecule expressing HBV antigens” would therefore confer a monopoly over approaches that “owe nothing to the invention.” Such over-breadth contravenes the principle that claim scope must mirror technical contribution (Exxon, British United Shoe).

Because the patent was not entitled to the 1978 priority date, Company A conceded that the claimed invention was obvious on the 1979 filing date, rendering the patent invalid. The same reasoning meant the specification was insufficient under s.72(1)(c), though that ground was not essential to the result.

The House also clarified that sufficiency is tested at the date of filing, not at publication, to ensure parallelism between the Patent Office’s examination duty (s.14) and the court’s revocation power (s.72).

Holding and Implications

APPEAL DISMISSED – PATENT INVALID

The House of Lords affirmed the Court of Appeal’s order revoking the patent and awarded costs to Company B. The decision reiterates that:

• Claim breadth must be commensurate with the inventor’s actual technical contribution.
• “Support” and “sufficiency” require an enabling disclosure that covers the full scope of the claims, not merely a single embodiment.
• Priority can be lost—and the patent rendered obvious—if an earlier application fails this test.

The ruling does not establish new precedent but consolidates United Kingdom and European Patent Office principles on claim scope, support and sufficiency, signalling to practitioners that early-stage biotechnology patents will be scrutinised for over-broad claiming.