Make no bones about it: The "credibility test" has no place in the novelty assessment of second medical use claims (T 0558/20)

A recent decision relating to bone regeneration therapy from the Boards of Appeal considered the correct approach to the assessment of second medical use claims. The Board of Appeal in T 0558/20 favoured an approach whereby the novelty of a second medical use should be assessed as a whole and not be restricted to the direct "medical use" steps of the claimed composition. The Board of Appeal also rejected the approach of the Opposition Division requiring a "credible" technical effect of the claimed use for novelty under Articles 54(4) and (5) EPC.

Legal Background: Second medical use claims

Medical methods are excluded from patentability in Europe (Article 53(c) EPC). This exclusion was included in the EPC 1973 to ensure there was no impingement of doctors' freedom to treat patients (G 01/07). However, in Europe, it is possible to patent "substances or compositions, for use" in a method of treatment. Particularly, a previously known substance or composition may be patented for a medical use if this specific use of the composition is new (Articles 54(4) and (5) EPC). 

Articles 54 EPC thus singles out "substances and compositions" as a special category of product. A known product for a new non-medical use cannot generally be patented, as this would be considered to lack a technical contribution to the art, or "technical teaching" (G 2/88). Particularly, a claim for a product for a non-medical use would be construed as a product "suitable for" the claimed use. If the product is already known, then the claim is thus anticipated by the product itself. It is therefore not possible to claim a hammer for use in hammering a new type of object, such as cheesecake, even if the prior art contains no reference to the use of hammers to hammer cheesecake. The prior art hammers will be considered to have been "suitable for" hammering cheesecake. 

By contrast, it is recognised that providing sufficient disclosure of a known "substance or composition" for a new medical use requires substantial research and development. The identification of a known "substance or composition" for a new medical use is therefore considered a technical contribution worthy of patentability. A second medical use claim is thus construed as including the functional effect of the claimed use. The new medical use of a known substance or composition is therefore considered novel (G 02/88, Articles 54(4) and (5) EPC). 

T 0558/20: Case background

Getting to the bones
of the matter

The patent (EP2588154) in T 0558/20 related to a bone tissue regeneration product for use in the treatment of degenerative bone diseases, such as osteoporosis. The question on appeal was whether the granted second medical use claim was novel in view of the fact that the claimed compositions and their general use in the treatment of bone disease was known. The only distinguishing features of the claim from the prior art were surgical method steps that, the Opponent argued, should not be considered a specific use of the composition falling under Article 54(5) EPC.

The correct approach to assessing novelty of a EPC 2000 second medical use claim

The Board of Appeal noted that it was self-evident that the method steps referred to in the granted claim related to a method of treatment. The method per se was thus excluded from patentability under Article 53(c) EPC. Claim 1 was also clearly drafted in the format provided for in Article 54(5) EPC, generally called "second medical use" (r. 2.5). 

The Board of Appeal noted that Article 54(5) EPC does not, as such, define any specific criteria to be applied when assessing the novelty of such a claim. For the Board of Appeal, the novelty of a second medical use claim over the prior art must therefore be assessed in the usual way. In other words, it is necessary to assess whether the specific use of the substance or composition defined in the claim is already known or not (r. 2.9). The Board of Appeal, however, identified two different approaches to this assessment. 

The Board of Appeal favoured an approach whereby it is first established whether the method referred to in the claims falls under the Article 53(c) EPC exclusion, i.e. is it a method of treatment of the human or animal body. It is then considered whether the specifically claimed use of the substance or composition in such a method is novel. For the Board of Appeal this approach was aligned with the logic of Article 54(5) EPC (r. 2.9). 

The Opposition Division (OD) in T 0558/20, on the other hand, had followed a different approach to the novelty assessment of second medical use claims. The OD reversed the steps and first assessed whether the specific use of the substance or composition defined in the claim was novel. Following this approach, if the specially claimed use is already known, the claim cannot benefit from the novelty exception. As such, the claim is not novel and it is then not necessary to assess whether the use falls under the Article 53(c) EPC exclusion or not. 

The Board of Appeal accepted that both approaches, if properly followed, should reach the same conclusion regarding the novelty of a second medical use claim. Nonetheless, it was the Board of Appeal's view that the OD's approach would be more prone to error (r. 2.10), which the Board felt was illustrated by the OD analysis in the case in question. 

The "specific medical use" of the composition should be considered as a whole 

Claim 1 of the patent specified materials for use in a method of treating a patient suffering from a degenerative bone condition. The method included surgical steps, such as creating space in the bone of the patient for filling with the bone regenerative material. The claimed materials were marketed for use in treatment of bone degeneration at the priority date. The new "characterising" part of the method thus solely resided in the surgical steps. 

The Opponent argued that these surgical steps did not specifically relate to the claimed materials. As such, the Opponent argued, the surgical steps could not contribute to the novelty of the claimed therapeutic use. 

The Opposition Division (OD) agreed with this argument. For the OD, the novelty of the claim was further dependent on the patentee making it "credible that a new technical teaching was provided" by the medical use. In doing so, the OD essentially incorporated a plausibility/credibility test into novelty analysis of second medical use claims (IPKat). Given the use of the materials for the treatment of bone disease was already known, the OD concluded that a new technical effect over the prior art could not be recognised, and thus the claim could not be considered novel under Article 54(5) EPC.

For the Board of Appeal, however, the surgical steps specified in the claim did form part of a "specific use in a method of treatment" as required by Article 54(5) EPC. The Board of Appeal particularly found that it was the method as a whole, i.e. the use of the materials in the treatment of bone disease comprising the surgical steps, that should be compared to the prior art disclosure. The Board of Appeal thus rejected the Opponent's argument that the surgical method steps of the claim should be excluded from the novelty analysis under Article 54(5) EPC. 

For the Board of Appeal, the claimed "additional physical actions" and "tangible, physical method steps" of the surgical steps could also be considered a technical teaching. The Board of Appeal therefore did not follow the OD approach requiring the patentee to demonstrate a "credible technical effect" of the claimed therapeutic use in order to establish novelty under Article 54(5) EPC.  The Board of Appeal reversed the OD decision and found an auxiliary request novel under Article 54(5) EPC on the basis of specific surgical steps not disclosed in the prior art with respect to the claimed materials. 

Final thoughts

For this Kat, the Board of Appeal interpretation of the requirement that a second medical use invention contribute a "technical teaching" (G 2/88) is in line with the case law on the patentability exclusion of abstract ideas. According to this case law, a patentable invention cannot be an abstract idea, but must have technical character (Case Law of the Boards of Appeal, I-A-1.1, G 2/88). The Board of Appeal did not follow the approach of the Opposition of Division, whereby the phrase "technical contribution" was interpreted as a credibility requirement for the treatment effect of the second medical use claim.

In recent years, the Boards of Appeal have moved progressively away from "special" tests for the novelty of certain types of invention. Particularly, Boards of Appeal have rejected the "purposive selection" criteria for novel sub-ranges (IPKat) and the requirement for purity by "unconventional means" for the novelty of purity inventions (IPKat). Boards of Appeal are increasingly rejecting these "special" novelty tests for being incompatible with the gold standard novelty test, whereby novelty is only destroyed by a clear unambiguous disclosure of the claimed invention in the prior art (G 2/88, G 2/10). 

In this Kat's view, the decision in T 0558/20 confirms that the gold-standard approach to novelty also applies to an assessment of novelty under Article 54(5) EPC. The requirement for a second medical use invention to possess "technical character" can therefore be considered a low bar. Whether the claimed medical use is inventive and can be performed over the full scope of the claim, remain considerations for sufficiency and inventive step analysis. 

Further reading

• Substance or device - a distinction without a difference? (Dec 2018)
• Plausibility demystified - a review of EPO case law before G 2/21 (Feb 2023)
• Boards of Appeal back rejection of special criteria for the novelty of purity inventions, but the Guidelines remain out of step (T 0043/18) (Aug 2022)
• Gold Standard test for novelty reigns supreme, even for subranges (T 1688/20) (Jan 2023)