30 January 2019

Patentability of methods of treatment and diagnosis

The European Patent Office’s (EPO’s) approach to the patentability of inventions in the medical field is based on the principle that medical practitioners should not be restricted at the point of care of a patient by the concern that a treatment or diagnostic method might be covered by a patent.

This has led to the provision of Article 53(c) of the European Patent Convention (EPC), which specifies that:

“European patents shall not be granted in respect of … methods for treatment of the human or animal body by surgery or therapy and diagnostic methods practised on the human or animal body…”

It may appear that Article 53(c) EPC significantly prohibits the patenting of inventions in the medical field in Europe. However, as discussed below, with careful wording, it is still possible to validly patent many inventions in the medical field.

Method of Treatment

Whilst methods of treatment are not patentable in Europe, it is possible to validly patent the use of a substance or composition for surgery, therapy or diagnosis under the provision of Article 53(c) EPC second clause, which states that:

“…this provision shall not apply to products, in particular substances or compositions, for use of these methods.”

This enables the use of a purpose-limited use claim to circumvent the exclusion of methods from patentability provided by Article 53(c) EPC.

If the substance or composition is known per se, but has not previously been used in a medical method, it is still possible to obtain broad protection for the use in any medical method using a so-called “first medical use” claim of the format “[Substance/composition] X for use in [therapy/in vivo diagnosis/surgery]” (Article 54(4) EPC), even if only one therapeutic use has been described in the patent. Thus, novelty and inventiveness is defined by the use of the substance or composition in a medical method, and not the substance or composition per se.

In addition, even if a medical use for any given substance or composition is already known, it is possible to protect a different medical use of that substance or composition using a claim in the format “[Substance/composition] X for use in [treating/ in vivo diagnosis of] Y]” (Article 54(5) EPC). In such claims, novelty can arise from the new disease that is treated. Of course, the Applicant must then show that treatment of the new disease would not have been obvious in order to demonstrate an inventive step.

A medical use claim can also be directed to specific uses of known substances or compositions for the new treatment of the same disease, and novelty and inventive step established by reciting new and inventive routes of administration (T51/93) and novel sub-groups of patients (T19/86).

Many medical methods involve the use of a medical device or apparatus. The use of first and second medical use claims is restricted to methods in which the medical effect is based on a substance or composition. Therefore, it is not possible to protect the use of a medical device or apparatus by a first or second medical use claim, as this is not regarded as a substance or composition within the meaning of Article 53(c) EPC. However, such medical devices can be protected by a claim drawn to the device per se, which will protect the device regardless of its use.

Surgery or Therapy

To be excluded as a method of treatment under Article 53(c) EPC, the treatment must be by surgery or therapy. If the treatment does not relate to either of these, then it will not be captured by the Article 53(c) EPC exclusion, and would therefore be patent-eligible.

Therapy relates to the curing, prevention or alleviation of a disorder or malfunction of the body, i.e. bringing a body back to its healthy state (T224/91). Thus, purely cosmetic treatments would not be classed as a therapy, as long as any cosmetic effect was not inextricably linked to a corresponding therapeutic effect.

Treatment by surgery relates to the nature of the treatment rather that its intended purpose. “Surgery” is defined as a physical intervention on the body, and methods that involve an invasive intervention are excluded from patentability as a method of treatment by surgery. The EPO Enlarged Board of Appeal has indicated that invasive methods comprise a substantial physical intervention on the body, which requires professional medical expertise to be carried out and which entails a substantial health risk even when carried out with the required professional care and expertise (G 1/07). Such methods may include injection, endoscopy, or excision amongst others. If a surgical step is not essential to the invention, we would recommend drafting the claims such that it is made clear that such a step precedes the claimed method. This can be achieved by use of expressions such as “pre-delivered”, “pre-implanted” or “pre-inserted”, and so on.

Diagnostic Methods

Methods of diagnosis are also excluded from patentability at the EPO. However, this exclusion has been interpreted narrowly by the EPO Enlarged Board of Appeal in its decision of G1/04, which sets out the conditions that must be met for a method to constitute a diagnostic method.

The claim must include method steps relating to all of the following phases:

(i) the examination phase, involving the collection of data,

(ii) the comparison of these data with standard values,

(iii) the finding of any significant deviation, i.e. a symptom, during the comparison,

(iv) the attribution of the deviation to a particular clinical picture, i.e. the deductive medical or veterinary decision phase (diagnosis for curative purposes stricto sensu).

Thus, to be excluded from patentability, a diagnostic method must include all of the necessary steps to obtain and analyse data, and come to a diagnostic conclusion. If any one of these steps is missing, the method will not be regarded as a diagnostic method embraced by the exclusion of Article 53(c) EPC. However, if all of these steps are seen as essential to the method, it would not be possible to simply delete one of these steps to circumvent this exclusion. Therefore, we would always recommend providing teaching in a patent application that highlights that one or more of these steps is not essential to the performance of the method, if possible.

Prognostic Methods are Patentable

Methods that do not lead to the diagnosis of a clinical picture are not excluded from patentability. For example, methods of data collection based on step (i) are patentable. Similarly, a method of data collection or analysis that does not enable a decision to be made on the treatment necessary (i.e. step (iv) above) will also be patentable, and we have had success for our clients arguing that methods of prognosis do not fall within the provision of Article 53(c) EPC, as they do not result in a diagnosis in the strictest sense of Article 53(c) EPC, in that the method of prognosis can be defined as predicting the rate of progression or improvement and/or the duration of a condition that has already been diagnosed.

Practised on the Human Body

In addition to the above steps, the exclusions only extend to treatments and diagnosis practised directly on the human or animal body.

Therefore, if a technical step of a claimed method is carried out in the absence of the body, the method should not be considered a diagnostic method excluded from patentability.

Thus, it is possible to protect the indirect (i.e. in vitro, ex vivo) treatment of a condition, or a diagnostic method, that is performed on body tissues or fluids after they have been removed from the human or animal body. Examples of the types of methods that would be patent-eligible include performing a diagnostic test on a blood sample or a treatment on an organ tissue before transplantation. However, treatment of blood by dialysis where the blood is returned to the patient would be excluded from patentability, as the patient would have to be present during the treatment.

In practice, we would recommend including at least one technical in vitro step and omitting any non-essential steps that are practised on the human body. For example, in a method that comprises a method of diagnosis based on identifying a particular biomarker in a blood sample, the step of actually obtaining the sample from a patient should be omitted from the claimed method, and the method may instead recite preforming the method “on a sample obtained from a subject”.


Methods of treatment by surgery or therapy and diagnostic methods practised on the human or animal body are excluded from patent protection at the EPO, and this may appear to significantly prohibit the ability of applicants to obtain patent protection in the medical field in Europe. However, by identifying the core aspects of an invention, and with careful claim drafting, it is often possible to circumvent these exclusions and protect many aspects of medical-related inventions.