Section 4A:  Methods of treatment or diagnosis
Source: gov.uk (2025-01-02)

Section (4A.01 - 4A.31) last updated January 2025.

4A.01

This section relates to exceptions to patentability and novelty. It is so framed to have, as nearly as practicable, the same effect in the UK as the corresponding provisions of the EPC, PCT and CPC, ie Articles 53(c), 54(4) and 54(5) of the EPC.

The Examination Guidelines for Patent Applications relating to Medical Inventions in the UK Intellectual Property Office (https://www.gov.uk/government/publications/examining-patent-applications-for-medical-inventions) provide further details on practice in this field.

s.130(7) is also relevant

4A.02

The term “therapy” includes the prevention as well as the treatment or cure of disease, as held by the Patents Court in Unilever Limited (Davis’) Application, [1983] RPC 219 (https://doi.org/10.1093/rpc/1983rpc219). Although some medical dictionaries cited pointed towards a narrow interpretation of the term, other works of reference, including non-specialist dictionaries, indicated a more general meaning; this was preferred in this case, following the principle that words in statutes dealing with matters relating to the general public are presumed to be used in their popular, rather than their narrowly legal or technical, sense. However, for a treatment to constitute therapy there must be a direct link between the treatment and disease state being cured, prevented or alleviated, as held by the hearing officer in Commonwealth Scientific and Industrial Research Organization’s Application (BL O/248/04) (https://www.ipo.gov.uk/p-challenge-decision-results/p-challenge-decision-results-bl.htm?BL_Number=O%2F248%2F04&submit=Go+%BB). A photodynamic method of controlling wool growth to reduce the incidence of blowfly strike and balanitis in sheep was therefore determined not to be a method of therapy. Furthermore, in Schering AG’s Application [1971] RPC 337 (https://doi.org/10.1093/rpc/88.14.337), it was held that a method of chemical contraception was not considered to be therapeutic. The prohibition does apply if a method of chemical contraception is associated with a therapeutic method by means of combined delivery system. This was decided by the EPO Technical Board of Appeal in The General Hospital Corporation’s Application T820/92 (OJEPO 3/95) (https://www.epo.org/law-practice/case-law-appeals/recent/t920820ex1.html) in which certain steroids were used in conjunction with a main contraceptive ingredient to alleviate health problems caused by that ingredient. The EPO Board of Appeal in another case, T74/93 (OJEPO headnote 4/95), confirmed that methods of contraception in general are not considered to be therapeutic, as pregnancy is not a disease. The Board held that the claimed method in this case lacked industrial applicability as it was a purely personal method carried out in private. In the UK methods of contraception are not considered to lack industrial application merely because they are for “private and personal use”. Under 60(5)(a) (/guidance/manual-of-patent-practice-mopp/section-60-meaning-of-infringement/#ref60-22) of the Patents Act 1977 the private use of such a method would not constitute an infringing act, and so a patent to such a method is allowable.

4A.03

It appears that any medical treatment of a disease, ailment, injury or disability, ie anything that is wrong with a patient and for which they would consult a doctor, as well as prophylactic treatments such as vaccination and inoculation, is to be regarded as therapy. The same considerations apply for animals as for human patients, so that for example prophylaxis and immunotherapy in animals are regarded as therapy.

4A.03.1

In Bristol-Myers Squibb v Baker Norton Pharmaceuticals Inc [1999] RPC 253 (https://doi.org/10.1093/rpc/1999rpc253), Jacob J held that the exception should be construed narrowly. Its purpose is merely to keep patent law from interfering directly with what a doctor actually does to a patient, not to stop patent monopolies from controlling what the doctor administers to the patient or the implements that they use on the patient. However methods of therapy carried out on materials temporarily removed from the body, for example when blood is circulated through an apparatus while remaining in living communication with the body, are not patentable (cf Calmic Engineering Co Ltd’s Application, [1973] RPC 684 (https://doi.org/10.1093/rpc/90.21.684)).

4A.03.2

In Ciba-Geigy AG’s Application (BL O/30/85), objection was raised under now repealed section 4(2) (equivalent to s.4A(1)) to certain claims for a method of controlling parasitic helminths (worms which may develop in the animal body, for example, in the intestinal tract of animals such as sheep) by the use of a particular (novel and inventive) anthelmintic composition. The hearing officer considered that such an infestation was a disease requiring medical treatment of the animal and that such treatment, whether curative or preventative, constituted therapy practised on the animal body and consequently held that the claims in question were not allowable.

4A.03.3

Section 4A(1) (#hi) excludes only treatment by surgery or therapy, and it follows that other methods of treatment of live human beings or animals, eg treatment of a sheep in order to promote growth, to improve the quality of mutton or to increase the yield of wool, are patentable provided that (as would probably be the case) such methods are of a technical, and not essentially biological, character. However, where an increase in meat yield or other industrial benefit is merely an inevitable consequence of improved health through therapeutic treatment, then such a method is unpatentable. On the other hand, a claim to the non-therapeutic use of antibiotics or other drugs may be acceptable if the claimed effect is not a mere consequence of improved health. Where the method set out in the claim may be patentable but could also cover non-patentable embodiments, a claim must be clearly limited (e.g. by a disclaimer) to methods which are patentable, and there must be support in the description for a non-therapeutic method. If necessary, the description should be amended to clarify that therapeutic methods do not form the invention.

4A.04

Application of substances to the body for purely cosmetic purposes is not therapy. In allowing claims to a process for improving the strength and elasticity of human hair and finger nails, the High Court of Australia observed that, while a process for the treatment of the human body as a means of curing or preventing a disease or other disorder was not patentable,

Those who apply chemical preparations to the skin to prevent sunburn in climates which enjoy sunshine and moderate air temperatures can scarcely be regarded either as, in a relevant sense, treating their bodies or as undergoing treatment. On the other hand, the application to the skin of an ointment designed and effective to remove keratoges from the skin would be an instance of medical treatment. To be treatment in the relevant sense, it seems to me that the purpose of the application to the body whether of a substance or a process must be the arrest or cure of a disease or diseased condition or the correction of some malfunction or the amelioration of some incapacity or disability.(Joos v Commisioner of Patents, [1973] RPC 59 (https://doi.org/10.1093/rpc/90.3.59)).

4A.05

In Oral Health Products Inc (Halstead’s) Application, [1977] RPC 612 (https://doi.org/10.1093/rpc/1977rpc612), claims to a method of removing dental plaque and/or caries were refused, as was a claim to a method of cleaning teeth which embraced both curative and cosmetic effects. This decision has been followed under the 1977 Act in ICI Ltd’s Application No 7827383 (BL O/73/82), where a claim was refused to a method of cleaning teeth which removed both plaque and stains; it was argued that when applied to perfectly healthy teeth the method was purely cosmetic, but the hearing officer observed that practically all medical treatments which are preventative in nature (such as vaccination) must at times be applied to people who would have remained healthy anyway, but they remained medical treatments. It was held in Lee Pharmaceuticals’ Applications, [1978] RPC 51 (https://doi.org/10.1093/rpc/1978rpc51), that since one of the results of sealing pits and fissures in teeth was to prevent the onset of dental decay, the purpose of the treatment was therapeutic rather than cosmetic.

4A.06

Diagnosis is the identification of the nature of a medical illness, usually by investigating its history and symptoms and by applying tests. Determination of the general physical state of an individual (e.g. a fitness test) is not considered to be diagnostic if it is not intended to identify or uncover a pathology. Section 4A(1) (#hi) relates to methods of diagnosis practised on the human or animal body; diagnosis in itself is a method of performing a mental act and is excluded from patentability under section 1(2)(c). The scope of the term “diagnostic methods practised on the human or animal body” within the meaning of Article 53(c) EPC (equivalent to section 4A(1) (#hi) is discussed by the EPO Enlarged Board of Appeal decision in G 01/04 Diagnostic Methods [2006] 5 OJEPO 334, [2006] EPOR 15. Typically, the process of diagnosis involves a number of steps leading towards identification of a condition. The Enlarged Board characterised these steps as being; (i) the examination and collection of data, (ii) comparison of the data with normal values, (iii) finding any deviation from the norm, and finally (iv) attributing the deviation to a particular clinical picture. The Enlarged Board held that for a claim to fall under this prohibition, it must include both the deductive step of making the diagnosis (step iv) and the preceding steps constructive for making that diagnosis involving specific interactions of a technical nature with the human or animal body. The exclusion is therefore a narrow one, and also requires all the method steps of a technical nature to be practised on the body. However, the Board pointed out that the exclusion could not be circumvented by omitting one of the essential features of the diagnostic method as the claim would then not satisfy Article 84 EPC (equivalent to section 14(5)(a) to (c)), since this requires that all the essential features necessary for clearly and completely defining a particular invention are present in the claim. In determining whether or not a method is diagnostic, the Board held that it is irrelevant whether it is necessary for a medical or veterinary practitioner to be involved. Furthermore, a method is “practised on the human or animal body” if it involves any interaction which necessitates the presence of the patient, so will include both invasive and non-invasive methods.

4A.06.1

In practice, there are two key questions to be asked with any claim to a diagnostic method. Firstly, does the claimed method include both the first, measurement step and the final deductive step; i.e. does it allow the disease or condition to be identified? (The intermediate steps (ii) and (iii) may be inferred if the first and last steps are clearly included.) Second, is the examination or measurement (step (i)) practised on the body? The remaining steps (ii) to (iv) are never practised on the body, but are generally not technical in nature. If the answer to both of these questions is “yes”, objection should be made under Section 4A (#hi).

4A.07

Methods of diagnosis performed on tissues or fluids which have been permanently removed from the body are not excluded, and so, for example, genetic or immunological tests on blood or urine samples are patentable. “Body” should be taken to mean living body, and a method practised on a dead body, for example in order to determine the cause of death, would not be excluded.

4A.08

Surgery is defined as the treatment of disease or injury by operation or manipulation. It is not limited to cutting the body but includes manipulation such as the setting of broken bones or relocating dislocated joints (sometimes called “closed surgery”), and also dental surgery. In general, any operation on the body which required the skill and knowledge of a surgeon would be regarded as surgery (see also 4A.10 (#ref4A-10)). The Enlarged Board of Appeal in G 01/07 MEDI-PHYSICS/Treatment by surgery [2011] 3 OJEPO 134 held that a method should be excluded if it comprises or encompasses an invasive step which constitutes a substantial physical intervention on the body, and which entails a significant health risk even when carried out by a medical professional.

4A.09

In Unilever Limited (Davis’) Application, [1983] RPC 219 (https://doi.org/10.1093/rpc/1983rpc219) (see also 4A.02 (#ref4A-02)), Falconer J observed that any method of surgical treatment, whether curative, prophylactic or cosmetic, is not patentable. This view, which was obiter, was cited by the hearing officer in Occidental Petroleum Corporation’s Application (BL O/35/84) in refusing to allow claims to a method of implanting an embryo transplant from a donor mammal into the uterus of a recipient mammal, since the method would necessarily have to be carried out by a surgeon or veterinary surgeon. In contrast, the EPO Technical Board of Appeal in T 383/03 GENERAL HOSPITAL/Hair removal method [2005] 3 OJEPO 159 held that the exclusion only applies to surgical methods which are potentially suitable for “maintaining and restoring the health, the physical integrity, and the physical well-being of a human being or animal, and to prevent diseases”. This was overturned by the Enlarged Board of Appeal in G 01/07 MEDI-PHYSICS/Treatment by surgery [2011] 3 OJEPO 134, in which it was held that the purpose of the method is irrelevant – the exclusion is not limited to therapeutic or reconstructive surgery. Instead, surgery is defined by the nature of the method, and in particular the level of skill required and risk incurred. This is consistent with previous UK practice, and with the Office decision in Virulite Ltd’s Application BL O/058/10. In this decision a claimed method of treating the skin with electromagnetic radiation was held not to be surgical on the grounds that it was not a significant physical intervention – the treatment did not damage cells or burn the skin – and the patent, if granted, would not interfere with the work of a medical or veterinary practitioner in their treatment of patients.

4A.10

It may often be helpful, in deciding whether or not a method is excluded under s.4A(1) (https://www.gov.uk/government/publications/the-patents-act-1977) to consider who would in practice carry out the method. The apparent purpose of s.4A(1) (https://www.gov.uk/government/publications/the-patents-act-1977) is to prevent a medical practitioner being inhibited by legal monopolies. Thus for example bone setting is regarded as surgery, while applying a plaster cast is not, since the former is carried out by a doctor, the latter by a technician. And in Upjohn Co (Kirton’s) Application, [1976] RPC 324 (https://doi.org/10.1093/rpc/93.12.324), the hearing officer observed that abortion in humans, in contradistinction to contraception, necessarily involved a registered medical practitioner. See also 4A.11 (#ref4A-11). However, this consideration is not decisive, and a method may still be considered to be therapeutic, diagnostic or even surgical even if it can be carried out by non-medical personnel. In G 01/07 MEDI-PHYSICS/Treatment by surgery [2011] 3 OJEPO 134 it was held that whether a method is excluded or not cannot depend on who carries it out, not least because of the changing medical roles in healthcare systems.

4A.11

Once it has been decided, in the way indicated in the preceding paragraphs, that a method constitutes surgery, therapy or diagnosis practised on the human or animal body, it is necessarily non-patentable. For example, methods of abortion or induction of labour are always considered to be unpatentable, irrespective of the reason for the treatment. The fact that abortion or induction of labour may be carried out for social reasons, or that these or other methods may be practised on animals for reasons of agricultural economies, does not save them from exclusion.

4A.11.1

Unlike section 1(2) of the Act, there is no proviso in s.4A(1) that methods are only excluded “to the extent that a patent or application for a patent relates to that thing as such”. The EPO Enlarged Board of Appeal in G 01/07 MEDI-PHYSICS/Treatment by surgery [2011] 3 OJEPO 134 confirmed a body of earlier EPO case law by holding that any multi-step method which includes a step comprising a method of surgery or therapy is excluded from patentability.

4A.12

Claims objected to under section 4A(1) (#hi) are often in the form “A method (or process) for treating medical or veterinary condition Y by …..”, but other forms of claim are also objected to such as “The use of substance (or composition) X in treating medical condition Y by …..”, “A compound (or composition) X when used in the treatment of medical condition Y by …..” and “The use of substance (or composition) X as a pharmaceutical”. The last of these claims is interpreted as a method claim to the use of the substance in therapeutic treatment, rather than simply a claim to its use in a pharmaceutical formulation.

4A.13

Patents may, however, be obtained for surgical, therapeutic or diagnostic instruments or apparatus intended for use in such methods. Also the manufacture of prostheses or artificial limbs and taking measurements therefore on the human body are patentable. In addition, tests on human or animal bodies should be regarded as patentable inventions if they do not meet the criteria for “methods of diagnosis” set out in 4.06 (#hn).

4A.14

If a claim is capable of embracing both excluded and non-excluded methods, amendment is necessary to limit the claim to methods which are patentable, for example by disclaiming the excluded methods, and if necessary, by amending the description to exclude the non-patentable methods. Any disclaimers must meet the requirements set out in xx-xxxx-xxxx. The Enlarged Board of Appeal in G 01/07 MEDIPHYSICS/ Treatment by surgery [2011] 3 OJEPO 134 confirmed that an “undisclosed disclaimer” (i.e. one where neither the disclaimer nor the subject matter excluded by it is disclosed in the application as filed) to exclude methods of treatment by therapy or surgery, or methods of diagnosis practised on the human or animal body, is in principle allowable and does not necessarily constitute added matter. Any form of disclaimer is allowed which removes the objection and leaves the scope of the monopoly remaining clear. While in ICI (Richardson’s) Application [1981] FSR 609 (https://uk.westlaw.com/Document/IC5D8ACE0E42711DA8FC2A0F0355337E9/View/FullText.html) a claim which included a disclaimer employing the wording of the Act was disallowed since it left the scope of what was being claimed unclear, there is no objection in principle to any other form of disclaimer, provided always that the scope of the monopoly remaining is clear, and there is support in the description for the invention claimed. Regardless of whether the disclaimer itself is disclosed, the subject matter remaining in the claim after the introduction of the disclaimer must be disclosed in the application as filed (G 02/10 SCRIPPS/Disclaimer OJEPO 2012, 376).

4A.15

This subsection is for the avoidance of doubt; the exclusions of s.4A(1) apply only to methods and not to materials to be used in such methods.

4A.16

Section 4A(3) has the effect that a known substance or composition may be patented for use in a method of treatment by surgery or therapy or a method of diagnosis practised on the human or animal body, provided that its use in any such method is new (“first medical use”). That is to say, if a known substance or composition not previously used in surgery, therapy or diagnosis is found to be useful in treating, say a human disease, or to obtain a specific “therapeutic” effect (eg analgesic or antibiotic), a patent for the substance or composition for use in therapy (unspecified) may be obtained, i.e. the claim need not be limited to the specific therapeutic effect; additional claims directed towards more than one specific therapeutic effect may be allowed in the same patent application, provided of course that they are supported by the description. The terms surgery, therapy and diagnosis are discussed in more detail in paragraphs 4A.02 (#ref4A-02) - 4A.14 (#ref4A-14).

4A.17

s.4A(1) is also relevant

This is an exception to the general rule (see 2.14 (/guidance/manual-of-patent-practice-mopp/section-2-novelty/#ref2-14)) that a claim to a substance or composition for a particular purpose is construed as a claim to the material per se, and that if the invention lies in a new method of using a known material only the new method can be claimed. (Where the new use is a method of surgery, therapy or diagnosis practised on the human or animal body a claim to the method would not be allowable). In a case where the main claims related to a contraceptive composition comprising compounds that were already known as pharmaceuticals, the EPO Technical Board of Appeal, in decisions T303/90 and T401/90 (not reported), was of the opinion that the composition as claimed could not be considered as novel and the added word “contraceptive” did not change the product claim into a use claim.

4A.18

The first medical use of a known substance can be claimed for use in a method of medical treatment the first time such a use is disclosed. Once the use of the compound in any method of medical treatment has formed part of the state of the art the same substance or composition may subsequently be patented for use in treating a different disease, whether human or animal, or in surgery or diagnosis as a second use (see 4A.26 (#hp) - 4A.31 (#hq)).

4A.19

s.1(2)(d) is also relevant

In Bayer A G (Meyer’s) Application, [1984] RPC 11 (https://doi.org/10.1093/rpc/1984rpc11), the hearing officer refused claims of the form “Commercial package containing as an active pharmaceutical agent compound X together with (or bearing) instructions …” for treating condition Y; it was only the content of the instructions which distinguished these claims from the prior art, and this was mere presentation of information and not an invention see 1.48 - 1.48.3 (/guidance/manual-of-patent-practice-mopp/section-1-patentability/#ref1-48) See also 4A.20 (#hr) below.

4A.20

A similar conclusion was reached in John Wyeth and Brother Ltd’s Application, [1985] RPC 545 (https://doi.org/10.1093/rpc/1985rpc545). In that case it was argued on behalf of the applicant that a claim to the use of X in treating Y included procedures which are not practised on the human or animal body but which are of an industrial nature, such as the preparation of the compounds and of compositions containing them and their packaging, including the enclosure of instructions, for the new use; a decision of the German Federal Court of Justice (Bundesgerichtshof), reported at OJEPO 1/84 pages 26-41, was cited in support of this view. The hearing officer rejected a suggestion that he was obliged, because of s.130(7), to follow this decision, and observed that there appeared to be a fundamental difference of approach to the validity of claims, since the German Court seemed to take the view that because a claim includes some patentable matter it should be allowed, whereas under UK law a claim as a whole is regarded as bad if it includes something that is non-patentable. In the judgment on (Schering AG’s Application [1985] RPC 545 (https://doi.org/10.1093/rpc/1985rpc545) at page 556) and on the Wyeth case, the Patents Court agreed with the findings of the hearing officer in the Bayer AG (Meyer’s) Application, [1984] RPC 11 (https://doi.org/10.1093/rpc/1984rpc11) but followed the EPO Enlarged Board of Appeal (G 05/83 EISAI/Second medical indication, [1985] 3 OJEPO 64) in allowing Swiss-type claims of the form “the use of substance X for the manufacture of a medicament for a specified new and inventive therapeutic application”; this type of claim has now been superseded by the direct form of second medical use claim as discussed in 4A.26 (#hp) - 4A.28 (#ref4A-28).

4A.21

A claim to a known substance or composition for the first use in surgical, therapeutic and/or diagnostic methods should be in a form such as “Substance or composition X ….” followed by the indication of the use, for instance “…. for use as a medicament”, “…. for use as an antibiotic”, or “…. for use in treating disease Y”. There is no objection to a claim being directed to substance X for use in a medical method in the case where X is novel, whether or not the substance is also claimed per se.

4A.22

EPO case law in relation to both first (T 1758/07) and second (T 1099/09) medical use claims indicates that protection for medical uses of known substances or compositions is only available for the use of a substance or composition as an active agent in medicine. The use of a known substance or composition as an inactive carrier or excipient for a therapeutic agent cannot therefore be protected by a first medical use claim. Following the same logic, the previous use of the compound purely as an inactive carrier or excipient for a therapeutic agent does not anticipate a first medical use claim, as held in T 1758/07.

4A.23

Section 4A(3) (#hu) is restricted to substances and compositions; apparatus cannot be so protected. Claims may be allowed however under Section 4A(3) (#hu) to compositions having a surface and in the form of an article ie having a shaped form.

4A.24

Since cosmetic methods of treatment of the human body are not considered to be therapeutic (see 4A.04 (#ref4A-04)), a substance or composition for use in a non-surgical cosmetic method cannot be protected by Section 4A(3) (#hu).

4A.25

To provide evidence of prior use of a substance or composition in therapy, actual disclosure of therapeutic use must be found. It is not sufficient for a research paper to disclose experiments which show an activity which would make the substance or composition suitable for use in therapy, or discloses in vitro testing for such a use. The section requires the use of the substance or composition in a method of therapy to form part of the state of the art. Such disclosures of experiments and tests might of course be used as a basis for an obviousness attack under section 3.

4A.26

Before implementation in 2007 of the medical provisions of the 2000 revision of the EPC (EPC 2000 – introduced into UK law by the Patents Act 2004), a second or subsequent medical use could only be protected by a claim in the “Swiss type” format of “the use of substance X for the manufacture of a medicament to treat disease Y”. Section 4A(4) now enables patent protection to be obtained for a second, or subsequent, different use of a substance or composition in a method of treatment or diagnosis by a direct claim in the form “substance X for use in the treatment of disease Y”. A claim of this type for a known substance or composition for use in a specific method of treatment or diagnosis is treated as new if that specific use was previously unknown. This does not extend the availability of patent protection in respect of an invention consisting of a substance or a composition for use in a method of treatment or diagnosis; it simplifies and clarifies the manner in which patent protection may be obtained for such inventions.

4A.27

Following implementation of the EPC 2000, the practice in both this Office and the EPO was to allow inventions relating to second medical uses to be claimed using either the direct second medical use claim format under Section 4A(4), or the Swiss-type format, or both, pending guidance from the UK courts and/or the EPO Boards of Appeal. In February 2010, the EPO Enlarged Board of Appeal issued its decision in G 02/08 ABBOTT RESPIRATORY/Dosage regime [2010] 10 OJEPO 456. This decided that applicants may no longer claim second medical use inventions in the Swiss format. The Enlarged Board held that Swiss-type claims were previously accepted (in G 05/83 EISAI/Second medical indication [1985] 3 OJEPO 64) as the only possible means of protecting inventions relating to second medical uses in order to fill a loophole in the provisions of the EPC 1973. The new Article 54(5) (equivalent to Section 4A(4)) fills this loophole by explicitly allowing claims to the further specific use of a known drug, and so the reason for this special, “judge-made” law no longer exists.

4A.27.1

Claims in the “Swiss-type” format in new or pending applications should be objected to on grounds of clarity, and must either be deleted or replaced by claims in the direct second medical use format “substance X for use in the treatment of disease Y”. This change in practice was announced in a Practice Notice issued on 26 May 2010. The basis of the objection is that a Swiss-type claim lacks clarity because, although it is worded as defining a method of manufacturing a medicament, the invention in fact relates to the intended use of the product rather than the method of manufacture. As stated in G 02/08, there is no functional relationship between the feature conferring novelty (the intended use) and the claimed manufacturing process. Amendment of a patent application to replace a Swiss-type claim with the new form of second medical use claim is not considered to add matter, since regardless of the wording or scope of the claim, the technical disclosure (i.e., a new medical use for a substance or composition) is the same. Similarly, replacement of an unpatentable method of treatment claim with a second medical use claim protecting the same use does not add matter. This practice does not have any bearing on the validity of patents already granted and including Swiss-type claims.

A request to make a post-grant amendment to replace Swiss-type claims with the new form of second medical use claim is unlikely to succeed, particularly as the Enlarged Board in G 02/08 suggested that the new form of claim may have a broader scope than Swiss-type claims. Moreover, in an earlier Technical Board of Appeal decision (T 250/05) it was held that a post-grant amendment from a Swiss-type claim to the new form of second medical use claim would extend the scope of protection and thus would not be allowable under Art. 123(3) EPC (equivalent to s.76(3)(b)). The Boards of Appeal in T 1780/12 and T 879/12 highlighted this difference in scope and also claim category between Swiss-type claims (which, strictly, are process claims) and the new form of second medical use claims (which are “purpose-limited” product claims). For this reason, it was concluded in both these decisions that where a divisional application included the new claim form, and the granted parent claimed the same medical use in the Swiss form, this did not constitute “double-patenting”. No objection should therefore be raised under s.18(5) or s.73(2) to conflict between applications including the new form of second medical use claim and granted GB or EP patents which protect the same medical use solely through Swiss-type claims. The Patents Court in Generics (UK) Ltd (t/a Mylan) v Warner-Lambert Company LLC [2015] EWHC 2548 (http://www.bailii.org/ew/cases/EWHC/Patents/2015/2548.html) held that Swiss-type claims are process claims – this construction was confirmed by the Supreme Court (Warner-Lambert Company LLC v Generics (UK) Ltd (t.a. Mylan) & Anor. [2018] UKSC 56 (http://www.bailii.org/uk/cases/UKSC/2018/56.html)) - this has consequences for infringement as discussed in 60.16.2 (/guidance/manual-of-patent-practice-mopp/section-60-meaning-of-infringement/#ref60-16-2) and 60.19.2 (/guidance/manual-of-patent-practice-mopp/section-60-meaning-of-infringement/#ref60-19-2).

4A.28

The protection of second medical uses by Swiss-type claims was originally allowed by the Enlarged Board of Appeal in G 05/83 EISAI/Second medical indication [1985] 3 OJEPO 64, and this was followed by the Patents Court in John Wyeth’s and Schering’s Applications [1985] RPC 545. The Enlarged Board in G 05/83 also decided that a claim to the use of a substance for treatment was regarded as confined to the step of treatment and was thus contrary to a.52(4) EPC [1973]. (See also 4A.20). Despite the fact that Swiss-type claims are no longer allowable, the case law that has developed from the UK courts and EPO Boards of Appeal concerning second medical use claims in the Swiss form continues to govern our practice in relation to the validity of inventions in this field. Second medical use claims which relate to the use of a substance for the same therapeutic application as the prior art, but claiming a different technical effect or mechanism of action, should be objected to for lack of novelty, and may also be excluded from patentability as a discovery. In Bristol-Myers Squibb v Baker Norton Pharmaceuticals [1999] RPC 253 (https://doi.org/10.1093/rpc/1999rpc253), the Patents Court held that a new piece of information about how a treatment worked did not constitute an invention if it did not lead to a new use, which was upheld by the Court of Appeal [2001] RPC 1. In this case, the drug, method of administration and therapeutic purpose were exactly the same as given in a prior lecture; the only difference was the discovery that if the drug was infused over a shorter time period, an undesirable side-effect was less and the therapeutic effect remained. This decision was followed by the Patents Court in El-Tawil’s Application [2012] EWHC 185 (https://www.bailii.org/ew/cases/EWHC/Ch/2012/185.html). In this case a claim was considered to relate to a combination of newly discovered technical effects, and newly discovered advantages of a known treatment, neither of which conferred novelty. Similarly, in Actavis UK Ltd v Janssen Pharmaceutica NV [2008] EWHC 1422, [2008] FSR 35 (https://www.bailii.org/ew/cases/EWHC/Patents/2008/1422.html), it was held that “merely explaining the mechanism which underlies a use already described in the prior art cannot, without more, give rise to novelty”.

4A.28.1

The Court of Appeal in Bristol-Myers Squibb v Baker Norton Pharmaceuticals [2001] RPC 1 (https://doi.org/10.1093/rpc/2001rpc0) also held that second medical use claims must define a new and inventive purpose; ie the treatment of a new disease. It was held that claims which defined the new use in terms of, for example, a new dosage regime, were disguised method of treatment claims, and also lacked novelty over the use of the substance to treat the same disease at a different dosage. However, the Court of Appeal in Actavis v Merck [2008] RPC 26 (https://doi.org/10.1093/rpc/rcn023) reversed this aspect of the Bristol-Myers Squibb v Baker Norton Pharmaceuticals decision and decided that a second medical use claim which defined the use in terms of a new and inventive dosage regime was valid, despite the fact that the substance in question had been used in the prior art to treat the same condition (alopecia) at a different dosage. It was emphasised that in most cases a new dosage regime would not be inventive, as investigating appropriate dosage regimes is standard practice.

4A.28.2

The reasons the Court of Appeal gave in Actavis UK Ltd v Merck & Co Inc. [2008] RPC 26 for departing from its own precedent (in Bristol-Myers Squibb v Baker Norton Pharmaceuticals [2001] RPC 1 (https://doi.org/10.1093/rpc/2001rpc0)) were threefold. Firstly it was decided that Bristol-Myers Squibb v Baker Norton Pharmaceuticals provided no clear ratio in relation to novelty, and so was not binding in this respect. Secondly, that the ratio of Bristol-Myers Squibb v Baker Norton Pharmaceuticals in respect of the method of treatment objection was on the narrow grounds that the claim at issue in that case was directed at the actions of the doctor rather than the manufacturer, and this was not the case with dosage regime claims in general. Finally, the Court of Appeal in any case felt it was able (but not bound) to depart from its own precedent on the grounds that the earlier decision was inconsistent with the “settled view” of European patent law as interpreted by EPO Board of Appeal decisions; which had allowed second medical use claims which define a new dosage regime or method of administration. The Enlarged Board of Appeal in G 02/08 ABBOTT RESPIRATORY/Dosage regime [2010] 10 OJEPO 456 confirmed earlier EPO case law in allowing second medical use claims to new and inventive dosage regimes, even where the substance or composition, and the disease to be treated, are the same as in the prior art. Second medical use claims which are distinguished from the prior art solely by the dosage regime used are therefore allowable if the claimed use is both new and inventive.

4A.28.3

As with first medical use claims, second medical use claims can only derive novelty from their intended use if the use is in a medical method excluded under s.4A(1), and so cannot be used to protect the new use of a known substance in, for example, a cosmetic method. Section 4A(4) is restricted to substances and compositions; apparatus cannot be so protected. In T 1099/09 it was held that second medical use claims can only be used to protect the use of a known substance or composition as an active agent. The use of a known substance or composition as an inactive carrier or excipient for a therapeutic agent cannot therefore be protected by a second medical use claim.

4A.29

Second medical use claims to the further medical use of a substance or composition must be supported by evidence, in the application as filed, that the substance or composition is (or at least is likely to be) effective for the specified use. In Prendergast’s Applications [2000] RPC 446 (https://doi.org/10.1093/rpc/2000rpc446), it was held that tests showing that the known substance or composition works in the proposed new circumstances are an essential part of the description if second medical use claims are to be adequately supported under s.14(5)(c). (Also see 14.152 (/guidance/manual-of-patent-practice-mopp/section-14-the-application/#ref14-152)). This ensures that purely speculative second medical use claims are not allowed. However, Neuberger J emphasised that rudimentary tests would suffice and that full, detailed and rigorous testing of the drug for the proposed condition is not necessary. The requirement for some experimental support for second medical use claims was confirmed by the Patents Court decision in El-Tawil’s Application [2012] EWHC 185 (https://www.bailii.org/ew/cases/EWHC/Ch/2012/185.html), and so an objection of lack of support should be made if such evidence is lacking, or is only present for some of the claimed diseases. Nevertheless, a claim to a broader class of diseases may be justified if the applicant can show that it could reasonably be predicted from the demonstrated activity that the substance or composition will treat the diseases in question.

4A.29.1

[Moved to 4A.30.1]

4A.29.2

These decisions relate to the requirement under s.14(5)(c) that a second medical use claim must be supported by the description. In addition, there is a body of case law relating to the requirements for sufficiency under s.14(3) for applications or patents relating to a second medical use. The UK Courts have followed the EPO Technical Board of Appeal’s decision in T 609/02 (https://www.epo.org/law-practice/case-law-appeals/recent/t020609eu1.html) in holding that the claimed medical use is a “functional technical feature” of the claim. This means, firstly, that if the agent is not effective for the treatment of the disease, then the application or patent is insufficient. In Eli Lilly & Co v Janssen Alzheimer Immunotherapy [2013] EWHC 1737 (http://www.bailii.org/ew/cases/EWHC/Patents/2013/1737.html), evidence obtained after the filing date (the failure of subsequent clinical trials) was held to show that the teaching of the patent was insufficient.

4A.29.3

Secondly, the Board of Appeal in T 609/02 held that the specification must disclose the suitability of the agent for the claimed therapeutic application. Absolute proof of efficacy, or clinical trials, was not necessary, but a simple assertion was not enough. The approach taken in T 609/02 was followed by the Court of Appeal in Regeneron Pharmaceuticals Inc v Genentech Inc [2013] EWCA Civ 93 (http://www.bailii.org/ew/cases/EWCA/Civ/2013/93.html), which held that the specification must make it “plausible” that the invention would work (i.e. be effective to treat the disease) across the claimed scope. This concept was summarised by Birss J in Hospira UK Ltd v Genentech Inc [2014] EWHC 1094 (http://www.bailii.org/ew/cases/EWHC/Patents/2014/1094.html): “The term “plausibility” has been coined to characterise what it is that a patent specification must provide in order to be sufficient, short of full clinical proof of efficacy.”

4A.29.4

This requirement for plausibility to render an application or patent relating to a second medical use sufficient was confirmed by the Supreme Court in Warner-Lambert Company LLC v Generics (UK) Ltd (t.a. Mylan) & Anor. [2018] UKSC 56. Moreover, the majority view in this case (as set out by Lord Sumption) set out a number of principles to assess the sufficiency of medical use claims: i) The proposition that a product is effective for the treatment of a given condition must be plausible. ii) It is not made plausible by a bare assertion to that effect, and the disclosure of a mere possibility that it will work is no better than a bare assertion. iii) The claimed therapeutic effect may be rendered plausible by a specification showing that something is worth trying for a reason; i.e. not just because there is an abstract possibility that it would work but because reasonable scientific grounds are disclosed for expecting that it might well work. The disclosure of those grounds marks the difference between a speculation and a contribution to the art. iv) Although the disclosure need not definitively prove the assertion that the product works for the designated purpose, there must be something that would cause the skilled person to think that there was a reasonable prospect that the assertion would prove to be true. v) That reasonable prospect must be based on a direct effect on a mechanism specifically involved in the disease, this mechanism being either known from the prior art or demonstrated in the patent per se. vi) This effect on the disease process need not necessarily be demonstrated by experimental data. It can also be demonstrated by a priori reasoning. vii) This evidence or reasoning must appear in the patent. The disclosure may be supplemented or explained by the common general knowledge of the skilled person. However, it is not enough that the patentee can prove that the product can reasonably be expected to work in the designated use, if the skilled person would not derive this from the teaching of the patent. It was emphasised that the specification as filed must make the claimed use plausible; data filed after the filing date of the patent can only be used to confirm an effect made plausible in the specification or to refute a contention that the treatment does not actually work; it cannot be a substitute for sufficient disclosure in the specification.

It is at present unclear whether the requirements for support for second medical use claims based on the decisions discussed in 4A.29 to 4A.29.3 is in any way different to the requirements for sufficiency following the criteria set out in Warner-Lambert Company LLC v Generics (UK) Ltd (t.a. Mylan) & Anor. [2018] UKSC 56 [2018] RPC 21 (http://www.bailii.org/uk/cases/UKSC/2018/56.html). It is common ground between these decisions that mere assertion of efficacy is not enough. However, in Prendergast’s Applications (https://doi.org/10.1093/rpc/2000rpc446) it was not suggested that the “material to enable the relevantly skilled man to say this medicament does treat the condition alleged” could be anything other than experimental evidence (of at least rudimentary nature). On the other hand, in Warner Lambert v Generics it was explicitly stated that plausibility could instead be derived from a priori reasoning (point vi). In view of the observation in Biogen Inc v Medeva plc [1997] RPC 1 (https://doi.org/10.1093/rpc/1997rpc1) that the requirements for sufficiency in s.14(3) and for support in s.14(5)(b) both relate to the requirement for an enabling disclosure, it is likely that the Courts would consider these to be essentially the same requirement.

4A.29.4.0

As the judgment of the UK Supreme Court in Warner-Lambert Company LLC v Generics (UK) Ltd (t.a. Mylan) & Anor. [2018] UKSC 56 (https://www.supremecourt.uk/cases/docs/uksc-2016-0197-judgment.pdf) is binding on the IPO of the UK, and all lower courts, the IPO does not follow the position taken by the Enlarged Board of Appeal in G 02/21 and its interpretation further set out in the final decision of T 116/18. In G 02/21 the Enlarged Board of Appeal discussed the general principle of free evaluation of evidence, while acknowledging, at paragraph 54, that there is no such principle in the UK common law system.

4A.29.4.1

G2/21 was considered in Sandoz Ltd v Teva Pharmaceutical Industries Ltd [2022] EWHC 822 (Pat) (https://www.bailii.org/cgi-bin/format.cgi?doc=/ew/cases/EWHC/Patents/2022/822.html&query) wherein the court held that the use of a factor Xa inhibitor, apixaban, for the treatment of thromboembolic disorders, a product falling within the scope of Bristol-Myers Squib’s (BMS) patent and the subject of a corresponding SPC, was not plausible based on the specification as filed. The patent in question contained a single statement that some compounds had been tested and found to have some binding affinity for factor Xa, however it was held that there was no way for the skilled person to derive any inference from this statement alone about any individual compound, be it apixaban or any other, regarding factor Xa binding. BMS attempted to argue that apixaban’s activity could be predicted by the skilled person a priori as a consequence of structural considerations based solely on their common general knowledge. Rejecting this argument, Meade J also reaffirmed the importance of the 7th Warner-Lambert principle (see discussion of Warner-Lambert above) that the requirement for plausibility must be met by a contribution from the patentee that is in the specification as filed – complete reliance on common general knowledge (CGK) is not enough, as CGK does not form part of the contribution of the patentee. This decision, and the subsequent appeal Sandoz v BMS [2023] EWCA Civ 472 (https://caselaw.nationalarchives.gov.uk/ewca/civ/2023/472?query=%5B2023%5D+EWCA+Civ+472), also emphasises that the requirement for plausibility is not limited to claims defining the medical use and is also applicable to (inter alia) per se claims: there is no invention in merely identifying a new chemical compound, in the absence of its utility being made plausible.

4A.29.5

The Supreme Court in in Warner-Lambert Company LLC v Generics (UK) Ltd (t.a. Mylan) & Anor. [2018] UKSC 56 (http://www.bailii.org/uk/cases/UKSC/2018/56.html) followed the principle set out in Biogen Inc v Medeva plc [1997] RPC 1 (https://doi.org/10.1093/rpc/1997rpc1) that sufficiency needs to be present across the breadth of the claim, and so for second medical use claims covering different conditions, the invention must be enabled across their full scope. Nevertheless, a claim to a broader class of diseases may be justified if the applicant can show that it could reasonably be predicted from the demonstrated activity that the substance or composition will treat the diseases in question. In Regeneron Pharmaceuticals Inc v Genentech Inc [2012], EWHC 657 (Pat)](http://www.bailii.org/ew/cases/EWHC/Patents/2012/657.html) (upheld at appeal [2013] EWCA Civ 93) (http://www.bailii.org/ew/cases/EWCA/Civ/2013/93.html), it was held, on the facts of the case, that it was reasonable to predict that an anti-angiogenic effect demonstrated in tumours would also extend to non-cancerous diseases characterised by excessive angiogenesis (growth of new blood vessels into a tissue).

4A.30

Insufficiency by excessive claim breadth has also been considered by the Courts in terms of the breadth of the class of agents, in addition to the range of conditions to be treated. The Court of Appeal in American Home Products Corp. v Novartis Pharmaceuticals UK Ltd [2000] EWCA Civ 231 (http://www.bailii.org/ew/cases/EWCA/Civ/2000/231.html), [2001] RPC 8](https://academic.oup.com/rpc/article/118/5/159/1587754) considered second medical use claims for a new use of a known antibiotic, rapamycin. The Court found that, had the claim been construed as covering derivatives (which it was not – see 4A.31 (#ref4A-31)), the patent would have been insufficient because there was no disclosure in the description enabling the skilled person to decide which of the many possible derivatives would have worked (see also 14.82- 14.84 (/guidance/manual-of-patent-practice-mopp/section-14-the-application/#ref14-82)). However, if the specification discloses a general principle capable of general application, a claim in correspondingly general terms may be acceptable – in Regeneron Pharmaceuticals Inc v Genentech Inc [2012] EWHC 657 (Pat) (http://www.bailii.org/ew/cases/EWHC/Patents/2012/657.html) (upheld at appeal [2013] EWCA Civ 93) (http://www.bailii.org/ew/cases/EWCA/Civ/2013/93.html), this test was applied and a functionally-defined claim to the use of antagonists of a particular receptor was considered to be a fair generalisation.

4A.30.1

The Patent’s Court in Hospira UK Ltd v Genentech Inc [2014] EWHC 1094 (http://www.bailii.org/ew/cases/EWHC/Patents/2014/1094.html) held that in order to establish a priority claim in the case of a second medical use invention, the earlier application must show that the claimed therapeutic effect is plausible. If this is not the case, then the earlier disclosure would not be considered enabling. Therefore, if a claimed priority application does not include any evidence beyond mere assertion of a therapeutic effect then the examiner should disregard this claimed priority date for the purpose of assessing novelty and inventive step (see 5.23.2 (/guidance/manual-of-patent-practice-mopp/section-5-priority-date/#ref5-23-2)).

4A.31

The Court of Appeal’s decision in American Home Products Corp. v Novartis Pharmaceuticals UK Ltd [2000] EWCA Civ 231, [2001] RPC 8 (http://www.bailii.org/ew/cases/EWCA/Civ/2000/231.html) also considered issues relating to the construction of second medical use claims. The Court of Appeal reversed the lower court’s decision and held that the claim – to the use of rapamycin for the preparation of a medicament for inhibiting organ or tissue transplant rejection – did not cover derivatives of rapamycin, thus finding the claim not infringed by the use of a rapamycin derivative as an immunosuppressant. Furthermore, the claim was held not to be infringed by the use of rapamycin to produce a derivative-based medicament, since this would require a wide construction of the term “medicament” in the claim (that is, to mean a medicament not restricted to one comprising rapamycin), and this would leave the claim hopelessly broad. The court also held that the claim was not infringed if rapamycin was present as an impurity in the derivative-based medicament, since there was no suggestion that at the quoted impurity levels the rapamycin had any effect.

In Bristol-Myers Squibb Co. v Baker Norton Pharmaceuticals Inc. [2001] RPC 1 (http://www.bailii.org/ew/cases/EWCA/Civ/2000/169.html), it was held that a second medical use claim directed to the manufacture of a medicament “for treating cancer” should be construed as “suitable for trying to treat cancer”, since the skilled person would realise that drugs which are suitable for treatment will not always have a 100% success rate. However, drugs which are perceived as being suitable for treatment, but actually have no effect, do not fall within the scope of the claim because they are not, in fact, suitable. Where two or more substances are used together to treat a disease, then each falls within the scope of a second medical use claim for the use of that substance (Pfizer Ltd’s Patent [2001] FSR 16 (https://uk.westlaw.com/Document/IE0E6F1E0E42711DA8FC2A0F0355337E9/View/FullText.html) at paragraphs 40-43). However, the previous use of the compound purely as an inactive carrier or excipient for a therapeutic agent does not anticipate a second medical use claim, as held in T 1758/07. In Hospira UK Ltd v Genentech Inc [2014] EWHC 1094 (http://www.bailii.org/ew/cases/EWHC/Patents/2014/1094.html) it was further explained (at paragraph 56) that “for treatment of [disease Y]” means “suitable and intended for treatment” – this definition was considered to apply to claims both in the Swiss form and in the “product for use” form. As second medical use claims are construed as being limited to the intentional treatment of the disease, the fact that the prior art use of the substance to treat a different condition may have inherently treated or prevented the claimed disease in some patients does not constitute an anticipation if the prior art does not disclose the new therapeutic use.

In an interim decision, the Court of Appeal in Warner-Lambert Company, LLC v Actavis Group Ptc EHF & Ors [2015] EWCA Civ 556 (http://www.bailii.org/ew/cases/EWCA/Civ/2015/556.html) held that “intended for” means that the manufacturer would know or could reasonably foresee that the product would be used for the claimed therapeutic method. In applying this test at the full trial (Generics (UK) Ltd (t/a Mylan) v Warner-Lambert Company LLC [2015] EWHC 2548 (http://www.bailii.org/ew/cases/EWHC/Patents/2015/2548.html)) Arnold J held that this meant the manufacturer would know or could reasonably foresee that a doctor or pharmacist would intentionally prescribe or administer the manufacturer’s drug for the claimed purpose. On appeal from this decision, the Court of Appeal (Warner-Lambert Company v Generics (UK) Ltd (t/a Mylan) & Ors [2016] EWCA Civ 1006) held that Arnold J’s interpretation was too restrictive – instead, all that is required (to fall within the scope of the claim) is that the manufacturer could reasonably foresee that there would be intentional use of the drug for the claimed medical use. However, the Supreme Court (Warner-Lambert Company LLC v Generics (UK) Ltd (t.a. Mylan) & Anor. [2018] UKSC 56 (http://www.bailii.org/uk/cases/UKSC/2018/56.html)) unanimously rejected the Court of Appeal’s interpretation of the scope of “Swiss-type” second medical use claims, and held that it was too broad an interpretation to say that “the use of [substance X] in the manufacture of a medicament for the treatment of [disease Y]” encompassed any manufacture of the product where the manufacturer could “reasonably foresee” that the product would be used for the claimed therapeutic method, although it was emphasised that this question (which related to infringement) was obiter as the patent was found invalid (see 60.16.1 (/guidance/manual-of-patent-practice-mopp/section-60-meaning-of-infringement/#ref60-16-1)).