The recent decision in T 0209/22 by the EPO Technical Board of Appeal, highlights the different thresholds for novelty and sufficiency in relation to a medical use claim.
Background
The case related to European patent EP2506844 which covers a combination of two known drugs, administered once-daily, for use in the treatment of asthma and chronic obstructive pulmonary disease (COPD). The patent disclosed data relating to monotherapy studies of the known drugs on patients, and data from a phase I clinical trial of the drug combination on healthy volunteers. Three oppositions were filed against the patent.
Opposition
The opponents tried to argue that the prior art, which disclosed a phase I clinical trial plan and summary of the combination drug, anticipated the subject matter and the technical effect claimed by the patent. However, the Board of Appeal decided that because the trial was conducted on healthy volunteers it could not anticipate the claimed therapeutic effect in patients. For medical use claims, the therapeutic effect itself is an inherent feature of the claim. The Board also found the technical effect claimed was credible from the combination of the monotherapy data and the clinical trial data.
The opponent subsequently argued that if the clinical trial and summary in the prior art wasn’t novelty-destroying, the clinical trial disclosed by the patent could not sufficiently support the claimed therapeutic effect. In addressing the novelty-sufficiency squeeze from the opponents, the Board of Appeals highlighted the different criteria for novelty and sufficiency.
For prior art to be novelty-destroying, the subject matter must be ‘directly and unambiguously’ disclosed. In contrast, for a technical effect to be sufficiently disclosed it does not need to be ‘directly and unambiguously’ disclosed. Instead, the technical effect must be credible from the application as filed. Seeing as the Board had already established the credibility of the therapeutic effect from the data filed in the application, the opponents’ sufficiency attack was not accepted by the Board.
The final issue contested was inventive step. The opponent argued that as the prior art independently disclosed both drugs of the combination for potential treatment of COPD, and the combination drug in a clinical trial, the skilled person would have a reasonable expectation of success for the combination drug in treatment of COPD.
However, the Board concluded that whilst positive preclinical data often provides good basis for further development of pharmaceutical compounds, it does not necessarily mean that there is a reasonable expectation of success as the majority of compounds fail before they reach the market. The Board also added that although the monotherapy prior art hinted to use the compounds in a combination drug, at the time of filing the prior art only provided the skilled person with a hope to succeed. Neither drug had actually been established in the treatment of COPD. As the prior art was deemed only to give the skilled person a hope of success, rather than a reasonable expedition of success, the Board accepted the inventive step of the invention.
Summary
This decision will be well received by patentees trying to get a medical use claim as it reinforces the takeaway message from the decision in T 1437/21. That is, a clinical trial protocol does not amount to a reasonable expectation of success. The case confirms that the threshold for novelty-destroying prior art is higher than the threshold for a demonstrating sufficiency of a technical effect. It also reinforces the importance of having a clear and detailed understanding of the state of the art at the time of drafting an application.