Background

However, there is a specific derogation from this requirement for absolute novelty. If an invention relates to a substance or composition which is to be used in a method of treatment of a human or animal body by surgery, therapy or diagnosis practised on that human or animal body then, even if that substance is known, that knowledge does not prevent the compound from being regarded as new, if the use of that substance or composition in any such method does not form part of the state of the art. In other words, it is possible to patent a known chemical compound as a pharmaceutical provided that it has not been previously known to have any pharmaceutical activity.

Research tends not to stop at one pharmaceutical activity and a particular pharmaceutical may, due to subsequent research, be found to have two or more pharmaceutical activities. To take an every day example, the drug, Aspirin, was originally marketed as a drug to alleviate headaches. It was subsequently discovered also to benefit those suffering from forms of heart disease. The research which goes into discovering such second medical uses can be enormous and the results may be no less worthy of patent protection than the original research which established the first pharmaceutical use. The exemption, however, does not allow patenting of these products themselves even if only in relation to treating the new disease.

If the development cannot be patented then there would be no protection against others using that finding for their own profit. Without the benefit of patent protection, new research into further uses of known drugs has less incentive.

The therapeutic use of that substance cannot be patented either. This is because that use is a method of treatment of a human or animal body by surgery, therapy or diagnosis which is practised on that human or animal body.

Methods of treatment are regarded in Europe as not being capable of industrial application and are consequently not patentable.¹

The EPO and the Swiss Patent Office tackled this problem in the early 1980's, with the Swiss Patent Office proposing the following solution²:

At the EPO, the Swiss claim was rapidly adopted. The Enlarged Board of Appeal held in the EISAI decision³ that claims relating to the use of a substance for the manufacture of a medicament were permitted where the novelty lay in the disease to be treated even if the manufacturing procedure was not in itself novel and the active ingredient was known.

The English Courts also looked at the Swiss type claims in 1985 in the case of Wyeth and Shering⁴ . This case was unusual in that both patent judges, Whitford J and Falconer J, sat en banc. The traditional English view is that merely indicating that something is "for" or "suitable for" a new purpose will not give novelty to subject matter which is already known. However, the Court allowed the Swiss form of claim to be granted in order to achieve conformity with EPO practice, although reservations were expressed as to whether or not those claims could be enforced against alleged infringers.

The Scope of a Swiss Claim

The Court of Appeal has now had a chance to look at Swiss claims in infringement proceedings, with some interesting results.

Monsanto -v- Merck⁵ came before the Court of Appeal on an appeal from a decision to strike out the allegation that the Swiss claim was infringed. Monsanto alleged infringement of a patent for a non-steroidal anti-inflammatory drug (NSAID). One common side-effect of NSAIDs is gastric irritation and the patented class of product was said to reduce this side-effect.

Although this was a new chemical class and so protectable per se, the patent also included at claim 20, a Swiss claim. The Swiss claim was in the form:

"Use of a compound of claim 1 for preparing a medicament for treating inflammation or an inflammation/associated disorder".

Merck intended to release a drug in which the active ingredient was known as MK-966. This was a "Keto form". Monsanto's claim 1 specifically covered the Enol form but not the Keto form and Monsanto contended that, after the Keto form had been administered to a patient, a significant amount of the Enol form would be produced. Moreover, Monsanto claimed that the Enolate form was also covered by the claim and that an Enolate anion (which produced both the Enol and Keto forms of MK-966) and the Enol form itself were present during production. They therefore alleged that claim 20 was infringed and, because a process claim is also infringed by importing and keeping the direct product of the process, that the final product also infringed this claim.

The matter came before Pumfrey J on an application for disclosure of documents (previously called "discovery") and directions. He questioned whether any disclosure relating to the manufacturing process was really necessary and suggested that a strike out application be brought. Pumfrey J felt that this was a clear case of construction. He stated "the presence of the compound in question during the course of manufacture of the active ingredient is, accordingly, in my judgment, not use of the compound in question for preparing the medicament". In other words, Pumfrey J took the position that a Swiss claim was directed to the process step of using the active ingredient to make the medicament and accordingly struck out Monsanto's allegations that Claim 20 was infringed.

The Court of Appeal took a completely different approach to the construction of the Swiss claim. The Court of Appeal held that the entire manufacturing process must be considered. Even if the infringing element was not the active ingredient, if it had been present at any stage during the manufacturing process, then there could be infringement. Consequently, the issue as to whether or not claim 20 had been infringed had to be understood in the context of the patent as a whole and a view on infringement could only be reached after the Court had heard the expert evidence and so been able to assume "the mantle of the man skilled in the art"⁶.

Swiss Claims -v- Methods of Treatment

Due to the fact that the element of the claim which gives it novelty and inventive step is the new method of treatment, there is a inherent tension between the Swiss form of claim and the prohibition in the European patent law against patenting methods of treatment. This came before the Court of Appeal in Bristol Myers Squib Co -v- Baker Norton Pharmaceuticals⁷. Bristol Myers' patent related to cancer treatment drugs. In particular, it related to taxol which is already known for use in cancer treatment because of it's ability to suppress cell division. However, this prevention of the replication of cancer cells also suppresses cell division in bone marrow and leads to the undesirable side effect of neutropenia. Claim 1 was therefore in the Swiss form but was expressed as follows:

"Use of taxol and sufficient medications to prevent severe anaphylactic reactions, for manufacturing a medicamentation for simultaneous, separate, or sequential application of from 135mg/m2 up to 175mg/m2 taxol over a period of about 3 hours or less as a means for treating cancer and simultaneously reducing neutropenia."

Although the claim failed on issues of novelty and inventive step, the Court of Appeal additionally found that this was not a Swiss claim but a disguised method of treatment. Taxol was a known anti-cancer agent and the only point of novelty lay in the length of time over which the drug was to be administered rather than in its therapeutic purpose. Moreover, the "manufacturing" process took place in the hospital pharmacy on a patient by patient basis, and so could not be considered as "an industrial application" (even if that "manufacture" was contracted out to a third party). This followed on from their decision in Monsanto -v- Merck that the Swiss claim is directed to the method of manufacturing a pharmaceutical.

Moreover, Buxton LJ stated:

Therefore Buxton LJ concluded that Bristol Myers' patent was "an improvement in the method of administering an existing treatment" rather than a new therapeutic purpose. Further judicial comment on Swiss claims may be provided shortly. The High Court has recently been considering Pfizer's Viagra patent. This too contains Swiss claims.

Conclusion

The initial doubts expressed by Whitford J and Falconer J that, despite granting Swiss claims, they would never be enforceable has not been borne out by pronouncements of the Court of Appeal to date.

The Swiss claim is a claim to a manufacturing process and not merely to the taking of the active ingredient and converting it into a special medicament. However, the distinguishing feature of the claim is the use to which that medicament is then put. That new medical use must be entirely new and cannot just be a modification of an existing treatment or a better method for treating the disease, for which the drug is already known to have an effect.

One of the interesting issues which still remains to be answered with respect to Swiss claims is that, if the formulation for treating the second medical use is no different from the formulation for treating the first medical use (i.e. known product used in old way but with new purpose), then how can a product which may already have been on the market before the second medical use patent was filed or the known method by which it is manufactured, now infringe the later patent? Does the simple act of giving new directions for use either in the literature accompanying the product or by advertising that this product has additional capabilities create an infringement? Although, Jacob J raised this issue in his first instance judgment in Bristol-Myers Squibb -v- Baker Norton, criticising the EPO for granting claims with no thought as to how they would be enforced, the Court of Appeal did not comment on this. However, the existence of the problem has been acknowledged at the highest level. Lord Hoffman in Merrell Dow -v- Norton⁸ stated that the doctrine which requires infringement to be absolute and independent of the state of the mind of the infringer would "be difficult to apply to a patent for the use of a known substance in a known way for a new purpose". However, he did not have to rule on it as the court "was not concerned with this aspect of the case"!