Medical use

First medical use

8.109 Whilst methods of treatment are excluded from patentability by virtue of Section 16(2), there is some relief for innovators wishing to patent substances or compositions used in methods of medical treatment. This is specifically provided in Section 16(3), which states that:

Subsection (2) shall not prevent a product consisting of a substance or composition from being treated as capable of industrial application merely because it is invented for use in any such method.

8.110 Section 16(3) is further supplemented by Section 14(7) which states that a known substance or composition for use in a method of treatment excluded by Section 16(2) will be new if the use of the substance or composition in any such method does not form part of the state of the art. Consequently, known substances or compositions which have not been used previously for medical purposes may be claimed in the form of a first medical use claim.

8.111 First (and second) medical use claims are often filed for new substances or compositions that have medical uses, in anticipation of any unforeseen prior disclosure of the claimed substance or composition that are found only after grant. Known substances or compositions not previously used for medical purposes may also be claimed in the form of a first (and/or second) medical use.

Forms of claim

8.112 A claim to the first medical use of a new or known substance or composition may broadly claim any therapeutic use. Examples of suitably drafted claims include:

(i) Compound X for use in therapy.
(ii) Compound X for use as a medicament.

8.113 It is clear that no single drug is suitable for treating all diseases. However, this broad  form of first medical use claim is allowable on condition that there is support for at least one medical use of the substance or composition claimed. The permissibility of this broad form of first medical use claim was deliberated by the Technical Board of Appeal (T 128/82 HOFFMAN-LA ROCHE/Pyrrolidine-derivatives OJEPO 1984, 164). It was decided that claims which did not state the specific therapeutic purpose were allowable if the substance or composition in question had not been previously used for any form of therapy, even if the specification only indicated one therapeutic use. It was further agreed that an inventor who for the first time discovered the use of a new or known compound for therapy should be duly given this broad form of protection.

8.114 First medical use claims may also be drafted in the form of a specific medical use claim and be worded in the form:

(iii) Compound X for use in the treatment of disease Y.

Both broad and specific first medical use claims are anticipated by any prior medical use of the compound. Essentially, regardless of the claim wording, be it in the form of either examples (i)-(iii), first medical use claims will lack novelty in view of earlier known use of the compound for any therapeutic purpose.

8.115 This differs from the UK and European patent practice, whereby specific medical use claims, in the form of example (iii), are only anticipated by the use of X for the specific treatment of disease Y. This is because, following the implementation of EPC 2000, such claims are regarded by UK IPO and EPO as limited to the specific medical uses claimed. In other words, in proceedings before the UK IPO and EPO, claims of this form are anticipated only when the use of X for the specific purpose of treating disease Y is disclosed.

8.116 Inappropriate first medical use claims include:

(iv) Compound X when used in therapy.

The claim of example (iv) is interpreted as a method of medical treatment and would not be capable of industrial application.

(v) Compound X for treating disease Y / Compound X for the treatment of disease Y.

The claim of example (v) lacks clarity. It is unclear if the claim is directed to compound X as “suitable for” treating disease Y or whether the intention is to limit compound X to the medical use of treating disease Y. In this scenario, the Examiner is to adopt the broader interpretation, wherein “for” is interpreted as “suitable for”. Accordingly, any disclosure of compound X, regardless of therapeutic inference would anticipate the claim of example (v) if the compound disclosed is in a form which would be suitable for the claimed use. For example, a disclosure of compound X used as a moisturizing agent, will anticipate a claim drafted in the form of (v) wherein disease Y is eczema.

8.117 In general, Section 16(3) is not relevant to substances or compositions that are not  used in a method prohibited by Section 16(2). The meanings given to “surgery”, “therapy” and “diagnosis” in Section 16(2) is applied equally to Section 1 (3). Therefore, Section 16(3) does not apply to substances or compositions that are used purely for cosmetic purposes since purely cosmetic methods are not considered as methods of treatment of the human or animal body by surgery or therapy or of diagnosis. Moreover, known substances or compositions drafted as a first medical use claim do not fall under the remit of Section 16(3) if there is no genuine prophylactic or therapeutic effect beyond, for example, the maintenance of a healthy diet (T 135/98 NORSK HYDRO [2004] EPOR 14).

8.118 A known substance or composition used as an inactive carrier or excipient for use in therapy cannot be protected by a first medical use claim. In order for a first medical use of a known substance or composition to be claimed, the substance or composition must be present as an active agent in a medicine. In T 1758/07 BIOTEC PHARMACON, a disclosure concerning the use of acid-hydrolysed yeast materials for improving the palatability of animal feed and the palatability of oral medicaments for administration to animals was considered to not anticipate a first medical use claim for the same composition. This was because the yeast hydrolysate in the prior art document was not used as an active agent for therapy of a disease but was instead used as an inactive carrier or excipient for a therapeutic agent. Even though this decision was made in relation to novelty, the same basis may be applied in determining the admissibility of an inactive carrier or excipient in the form of a first (or second) medical use claim. For this reason, an inactive carrier or excipient for a therapeutic agent cannot be claimed in the form of a medical use claim and the claim would lack support if claimed as such.

Novelty and inventive step assessment of first medical use claims

8.119 Any disclosure of the claimed substance or composition as a therapeutic agent will anticipate a first medical use of the substance or composition. However, in some instances, it is not necessary for the compound to have been isolated in the prior disclosure if, by carrying out the methods of the earlier disclosure, the compound would have been inevitably made. Specifically, in Merrell Dow Pharmaceuticals Inc v H N Norton & Co Ltd [1996] RPC 76, which centred on a claim to an acid metabolite formed in the liver after administration of terfenadine (itself the subject of an earlier patent), the acid metabolite was held to be anticipated not because of prior use but because it was the inevitable result of carrying out the instructions as taught in the earlier terfenadine patent.

8.120 Actual therapeutic use of the claimed substance or composition must be indicated in non-patent documents for it to be considered an enabling disclosure. Disclosure of experiments in non-patent documents demonstrating an activity which would make the substance or composition a suitable candidate for use in therapy or disclosure of in vitro testing for such a use is not considered as an anticipatory document unless actual therapeutic use can be inferred from the document (implicit disclosure). This document may of course serve as a basis for an obviousness objection under inventive step.

8.121 However, when the application contains only in vitro experimental data and the only difference between the application and the prior art document is the assertion of a therapeutic use, then the Examiner may still object to the claim for lacking novelty since there was no new technical feature provided in the application that confers novelty to the claim (T 1031/00 SEPRACOR INC.).

8.122 A statement indicating the therapeutic uses of the claimed substance or composition in a patent document without accompanying clinical data may be cited for novelty. This statement is considered to anticipate the first medical use of the claimed substance or composition and the onus is on the Applicant to challenge whether such a document constitutes an enabling disclosure. As discussed in T 1001/01 SMITHKLINE BEECHAM:

“… it is common practice that a patent literature document, in order to be an enabling disclosure of a medical indication for pharmaceutically active compounds … does not necessarily need to include either clinical tests (Phase I, II or even III) or in vivo human assays.”

8.123 As medical use claims are limited to the intentional treatment of a disease, the disclosure that the substance or composition of interest has previously been administered or ingested would not anticipate a first medical use claim if there was nothing in the prior art documents to indicate any therapeutic benefits even though this may have inherently occurred.

Support for first medical use claims

8.124 First medical use claims must be supported by evidence of the likely efficacy of the substance or composition in therapy. However, the Applicant is entitled to a broad form of claim (such as in examples (i) and (ii)) in the case of a substance or composition, wherein its use in medicine is previously unknown. Therefore, it is unlikely a first medical use claim will lack support as long as the Applicant provides credible evidence of the efficacy of the claimed substance or composition for use in the treatment of any one, if not more diseases. For a first medical use claim drafted in form of example (iii): “Compound X for use in the treatment of disease Y”, support has to be provided for the specified use.

8.125 This requirement of support for known substances or compounds is based on the decision of the Patents Court in Prendergast’s Applications [2000] RPC 446. Although this case law is pertaining to support for “Swiss-type” claims, it remains nonetheless relevant to first medical use claims. It was held in Prendergast’s Applications that since the distinguishing feature of the “Swiss-type” claim from the prior art is its intended use, this use must in turn, be supported by credible evidence.

8.126 This requirement of support is also mandatory for new and inventive substances or compositions. This view was held by the Hearing Officer in F. Hoffman – La Roche’s Application BL O/192/04:

“Support is needed for claims to the use of compounds for therapy, regardless of whether the compounds are themselves new or inventive.”

8.127 The form of evidence is not critical. In vivo, in vitro and in silico modelling data may prove sufficient if it is considered a credible form of support of its efficacy in a medical use. However, the level of evidence provided will be decided upon a case-bycase basis as it may also be dependent upon the state of the art in relation to a particular application. In F. Hoffman-La Roche’s Application BL O/192/04, homology comparisons of the claimed polypeptide were used to determine biological activity by reference to a polypeptide of known activity. It was concluded that although the description provided support for the function of the Npt2B polypeptide in its native state, this support cannot be read across to the claimed polypeptide in an isolated, nonnaturally occurring environment. The Hearing Officer was of the view that it is unlikely the Npt2B polypeptide will retain its native state structure when isolated in 99% pure form and hence it was also unlikely that the polypeptide retained its function as a sodium phosphate transporter. Moreover, in the absence of any evidence demonstrating the efficacy of the isolated polypetide in a non naturally occurring environment, the claims relating to the therapeutic uses of the isolated form of Npt2B polypeptide were considered to lack support.

8.128 The evidence in support of first medical use claims must be provided in the application as filed. The absence of this would result in the first medical use as being no more than mere speculation. In such instances, the Examiner is required to inform the Applicant of the lack of support for the claimed first medical use. This objection cannot be overcome by later-filed data.

8.129 Moreover, if the application claims priority from an earlier application and there is no evidence in that earlier application of the therapeutic use of the claimed substance or composition, then claims relating to the medical use of the substance or composition would not be entitled to a priority date based upon the earlier application.