Validity - Enablement; and novelty, obviousness and second medicinal use

Enablement and Priority Date

In Chiron Corporation v Evans Medical the Patents Court, said that in assessing whether a Patentee is entitled to an earlier priority date, the onus is on the Patentee to show that the priority document discloses the invention claimed in the later specification. However, although the onus is on the Patentee, in a normal case the court will proceed on the basis that the technical results in the priority document can be achieved as asserted. If that claim is not effectively challenged, the Patentee has done enough.

In this case the priority document did not sufficiently disclose the claimed invention. The Court stated that, if following the instructions in the priority document produces results which are inconsistent with what the Inventor describes as his achievement, than the addressee will appreciate that something is wrong. If it is apparent that the general teaching is wrong, and the examples are correct and the addressee can follow them, then the latter are enabled. If it is apparent that one or more of the examples is incorrect, but the addressee can follow the general teaching and such examples as are clearly accurate without undue difficulty, then the general teaching is enabled. If the reader does not know which is correct then it is difficult to see how the priority document can be enabling.

If reasonable addressees can come to different conclusions, there is a conundrum as to which is right. This is not enablement.

The priority document in this case referred extensively to the production of adenylate cyclase. However, subsequently the Patentee discovered that the effective agent was not adenylate cyclase but pertacin. Pertacin was not referred to in the priority document, only in the complete specification as filed, so the priority document did not enable the invention claimed and the patent was not entitled to the claimed priority date.

Bristol Myers Squibb Co v Baker Norton Pharmaceuticals

The Plaintiff, BMS, was the proprietor of an European Patent (UK) for use of a preparation of taxol. Claim 1 of the patent (UK) was in Swiss form as follows:

• use of taxol and sufficient medications to prevent severe anaphylactic reactions;
• for manufacturing a medicamentation for simultaneous, separate or sequential application;
• for the administration of [specified quantities of] taxol over a period of about 3 hours or less;
• as a means for treating cancer; and
• simultaneously reducing neutropenia.

The judge took the view that the claim was not a claim to a mere method of treatment (which would have rendered it unpatentable) on the ground that the medicamentation of the claim comprises the Taxol made up to be patient-specific, and so was a claim to manufacture.

It was accepted that a BMS employee, Dr Winograd, had disclosed the first four features in a public lecture given before the priority date. The question arose as to whether or not the last feature made the idea novel and inventive.

The judge came to the conclusion that neutropenia (the fall in the white cell count in chemotherapy using taxol) was inevitable. Further, given the concern at the effect of neutropenia during and following chemotherapy, the white blood cell count would be carefully monitored and the reduction in neutropenia was a mere discovery, so that the added feature did not give validity to the claim over the other, admittedly prior disclosed, features. Further, inevitably, he regarded it as obvious.

The Defendants also raised an attack on the Swiss form of claim. The judge referred to Eisai in which the Enlarged Board of the European Patent Office considered that a newly discovered use of aspirin in a claim of Swiss form gave validity to such a claim. He refused to overturn Eisai, particularly given the decision of the English Patents Court, sitting en banc (Whitford and Falconer JJ) in Wyeth and Schering’s Application where the Court, having taken the preliminary view that a claim in Swiss form should not confer novelty, felt constrained, in view of Eisai and “having regard to the desirability of achieving conformity”, to follow Eisai. The judge considered that, as a judge of first instance, to refuse to follow a decision of law of the Enlarged Board of Appeal and the English Patents Court sitting en banc would not be desirable. The judge’s view was reinforced by the comments of Lord Hoffman in the House of Lords in Merrell Dow where he refused to overturn Eisai. The judge also pointed out that the Enlarged Board had refused to consider questions of infringement saying in Eisai:

“It is particularly important to bear in mind that Article 64(3) leads questions of infringement to be dealt with by National Law”.

In supporting their case for novelty BMS also relied on the decision of the Enlarged Board in Mobil/Friction Reducing Additive where the Enlarged Board had said that “With respect to a claim to a new use of a known compound, such new use may reflect a newly discovered technical effect described in the patent. If that technical effect has not been previously made available to the public then the claimed invention is novel, even though such technical effect may inherently have taken place in the course of carrying out what has previously been made available to the public”.

Again, the judge refused to consider a full scale assault on Mobil, despite his being well aware of the difficulties of the decision, as the House of Lords in Merrell Dow had clearly declined to criticise it.
The judge also felt that there was no logical or reasonable distinction between Mobil and Eisai, and so to try and steer a course between accepting Eisai and holding Mobil wrong was, at best, going to involve Byzantine, logic so he refused to distinguish Mobil
and Eisai.

In trenchant terms, the judge concluded:

“I should only add that it is apparent that the decision in Mobil (and by implication in Eisai) is causing considerable difficulty to national courts. It is not good enough for these difficulties to be brushed aside. Substantive European patent law demands a holistic approach to infringement and validity. Moreover, by virtue of the EPC and CPC it should have. For myself, although I have no power of direct reference, I hope that the EPO will find a way of convening a fresh Enlarged Board (ideally including Judges with experience of infringement - [a long held view of the judge] to consider Mobil."

Hopefully that request will be granted and will lead to European patent law becoming more logical and clearer. However we would not expect any such change to be likely to be imminent.