T 0609/02 - No second medical use claim based on speculation - #92

Rank: 92
No. of citations: 56

T 609/02 deals with second-medical-use claims and looks at how much experimental evidence is required to make the second-medical-use claim is sufficiently disclosed.

Second-medical-use claims seek to protect the use of known substances or compositions for a new medical purpose. Under the EPC1973 second-medical-use claims had to be formulated in the "Swiss-type" format ("use of compound X for the manufacture of a medicament against disease Y"). Under the EPC2000 the a purpose-limited-substance-claim format ("substance X for treating disease Y") must be used.

Since second-medical-use claims confer valuable protection for new pharmaceutical treatment schemes, and research in this area is expensive and slow, applicants tend to file speculative patent applications claiming a second-medical-use way before hard data of the respective substance in the specific medical indication claimed is available. Arguably, the invention is not ready at this point.

The Board in T 609/02 looked at the following claim:

"6. The use of a steroid hormone or steroid hormone analogue as identified by the method of claims 1 to 5, which fails to promote transcriptional activation of glucocorticoid receptor or retinoic acid receptor genes, for the preparation of a pharmaceutical for the treatment of AP-1 stimulated tumor formation, arthritis, asthma, allergies and rashes."

The Board noted correctly that the claim - on top of being a second-medical-use claim - was also in the controversial "reach-through claim" format (see EPO Guidelines F-III, 9). The "reach-through" issue, however, could be left aside, because the claim was not allowable for other reasons.

Specifically, the Board noted that the patent specification only described a study of the "interplay" between the steroid hormone/steroid hormone receptor complex regulating the transcription of steroid hormone-responsive genes and the AP-1 protein regulating the transcription of AP-1 responsive genes. The Board stated that the patent specification, however,

"... provides no evidence at all relating to the invention in claim 6: no steroid hormone is identified as binding to the hormone receptor in such a way that the so-formed complex will disrupt AP-1 stimulated transcription and at the same time fail to promote steroid hormone regulated transcription; no data of any kind are presented indicating that such an hormone (if it were identified) could have an impact on any of the listed specific diseases." (point 5 of the reasons)

Only later, the applicant provided post-published evidence showing that steroid hormones such as needed to carry out the use according to claim 6 were later structurally identified and that they, indeed, have an effect on AP-1 stimulated transcription. They argued that on the basis of the disclosures of these post-published documents, by carrying out the claimed invention, one would necessarily obtain pharmaceutical compositions since it was by following the teachings of the patent in suit that the post-published results had been obtained. Consequently, in the appellant's opinion, sufficiency of disclosure had to be acknowledged.

The Board disagreed. They stated:

"Sufficiency of disclosure must be satisfied at the effective date of the patent, ie on the basis of the information in the patent application together with the common general knowledge then available to the skilled person. Acknowledging sufficiency of disclosure on the basis of relevant technical information produced only after this date would lead to granting a patent for a technical teaching which was achieved, and, thus, for an invention which was made, at a date later than the effective date of the patent. The general principle that the extent of monopoly conferred by a patent should correspond to, and be justified by, the technical contribution to the art, has to be kept in mind (eg. decision T 409/91, OJ EPO 1994, 653)." (point 8 of the reasons)

In other words, sufficiency of disclosure is a requirement that must be fulfilled at the time of filing. No patent should be granted on the basis of mere speculation that a possible second-medical-use exists. Post-published evidence that the second-medical-use indeed exists cannot cure the fundamental deficiency of lack of sufficient disclosure.

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Headword:

If the description of a patent specification provides no more than a vague indication of a possible medical use for a chemical compound yet to be identified, later more detailed evidence cannot be used to remedy the fundamental insufficiency of disclosure of such subject-matter.