Following the decision of the Supreme Court of England and Wales that Human Genome Sciences Inc’s (HGS) patent for Neutrokine-α was not invalid for lack of industrial applicability, the Court of Appeal has decided the remaining validity issues in relation to three claims. It upheld the first instance decision that one of these claims was valid, and reversed the finding that the other two were insufficient.


Eli Lilly and Co (Lilly) brought an action to revoke EP0939804 (the patent) held by HGS. The patent disclosed the nucleotide and amino acid sequence of a new member of the Tumor Necrosis Factor ligand superfamily, called Neutrokine-α. This family of proteins is involved in inter-cellular signaling in inflammation and immune responses. HGS discovered Neutrokine-α using bioinformatics and filed the patent before any practical use had been identified. The patent identifies Neutrokine-α and includes a long list of uses based solely upon what was known about other members of the family.

In opposition proceedings at the European Patent Office (EPO), the opposition division revoked the patent on the basis that the invention lacked inventive step. Subsequently, in the High Court, Kitchin J held that the patent was invalid for lack of industrial applicability and obviousness, while the claims to pharmaceutical and diagnostic compositions were invalid for insufficiency. Both decisions were appealed.

The Court of Appeal decided to uphold Kitchin J’s decision rather than following the decision of the EPO’s technical board of appeal. The Supreme Court decided unanimously to allow a further appeal and held that Kitchin J and the Court of Appeal had not applied properly the relevant principles of patent law in this case. The case was remitted to the Court of Appeal to deal with the outstanding issues of the validity of claims 13, 18 and 19 of the patent.


At the time the patent was filed, no one knew whether Neutrokine- α or any of its antibodies would actually be valuable products. Research since then has led to identification of specific antibodies to Neutrokine-α that were promising for the treatment of diseases such as lupus and rheumatoid arthritis. All these products have their own patents. If claim 13 was valid, the developers of these downstream products would have to pay royalties to HGS as holder of the master claim to all Neutrokine-α antibodies.

Lilly argued insufficiency on the basis that even though individual antibodies could be isolated and made, the patent gave no clue as to which, if any, actually had any practical use, and it would take significant effort to identify those that did. This argument was rejected by the Court, as the skilled reader was not led to expect any specific activity. Claim 13 did not contain any limitation to usefulness, only a multitude of possibilities, and simply identified an antibody that specifically binds to Neutrokine-α. That in itself is its potential utility. The Court deemed it irrelevant whether discerning any particular specific utility might involve undue effort, or that one product might well be less useful than another.

HGS contended that Kitchin J had proceeded on an erroneous construction in relation to claims 18 and 19 because, read in the context of the specification as a whole, the skilled reader would not have expected the patentee to have intended these claims to be directed to compositions with immediate practical use. This was in line with the Supreme Court judgment that the phrase “a pharmaceutical/diagnostic composition” was a common way of claiming an ingredient in a packaged form and did not promise any particular effect. It followed, therefore, that the claims were only for compositions that could be formulated as suitable for administration as a pharmaceutical, or suitable for use as a diagnostic. That could be done, so the claims were sufficient. The Court of Appeal accepted this submission, finding all the claims considered to be valid.


The finding of validity of these claims was not much of a surprise considering the interpretation of the Supreme Court. Sir Robin Jacob, however, made an interesting comment relating to potential royalty rates: “The question would be, what is a “reasonable term” fixing the amount payable, and the assessment of that might well include the degree of risk, expense and work incurred by the respective parties”. This seems to caution HGS over the level of royalty payments it sets in relation to a patent that did not involve the effort and expense that developing a useable pharmaceutical involves.