Clinical trials series, Episode 1: Clinical trials as prior art and their impact on novelty

Clinical trials series, Episode 1: Clinical trials as prior art and their impact on novelty

In this first article in this new series, we will consider the effect of the publication and conductance of clinical trials protocols on novelty at the EPO. 

Clinical trials protocols as prior art 

According to Article 54 EPC, the EPO considers the state of the art to comprise "Everything made available to the public by means of a written or oral description, by use, or in any other way, before the date of filing of the European patent application". Therefore, applicants may believe a clinical trial protocol disclosing their claimed compound for use in treating a certain disease, published before the priority date of the application, could adversely affect the novelty of their claim. However, this is not necessarily the case. In Europe, the attainment of the therapeutic effect is itself considered a functional feature of the claim. 

If we take an example medical use claim, such as: 

“Compound X for use in a method of treating disease Y at a dose of 100mg” 

A published clinical trial design/protocol disclosing the same compound, for the treatment of the same disease, at the same dosage, would not destroy the novelty of this claim at the EPO. This is because the prior art in this example is a clinical trial protocol, published without results.  

The EPO’s Technical Boards of Appeal in T158/96 and T1859/08 demonstrate the EPO’s stance that the results of a clinical trial are required to destroy novelty. T158/96 explicitly states in the headnote that 

"The information in a citation that a medicament is undergoing a clinical phase evaluation for a specific therapeutic application is not prejudicial to the novelty of a claim directed to the same therapeutic application of the same medicament if…the content of said citation does not allow any conclusion to be drawn with regard to the actual existence of a therapeutic effect."

It follows that applicants applying for a patent with claims directed to a compound for use in a medical method, wherein only the clinical trial protocol forms part of the state of the art (and not any results of the trial), should not be concerned about the effect of this protocol disclosure on the novelty of such claims. 

Clinical trial protocols may also be relevant when claiming new combinations of known compounds, as the safety/toxicity of the therapy may also be relevant to patentability. According to Board of Appeal decision T2506/12, “efficacy and safety have to be taken into account to determine whether an effective treatment is implicitly disclosed in the prior art”. In the case underlying that decision, the compounds of the claimed combination were known independently as effective monotherapies, and two of the cited documents disclosed that a phase I clinical trial to the combination was taking place. However, the Board believed that the skilled person could not rule out that the compounds may interact in combination to have an adverse effect or dose limiting toxicity that would preclude the attainment of a therapeutic effect. Again, the prior art relating to the clinical trial did not disclose the successful result of the clinical trial, and therefore the disclosure was not considered to be novelty destroying.  

Clinical trials and the novelty of compound per se claims 

Although a published clinical trial protocol may not destroy the novelty of a medical use claim, it is possible that the conduction of the clinical trial itself may constitute the claimed compound being "made available to the public" according to Article 54 EPC, even without the disclosure of the results. This depends on whether the EPO considers the conduction of the trial to have rendered the claimed compound (or formulation thereof) publicly available. 

In the case underlying T7/07, a lack of novelty arose over a clinical trial itself due to the drug having been made available to the public before the time of filing. On account of the study participants not being bound by explicit confidentiality and them being permitted to take the drug tablets home without restriction, the EPO considered the investigators to have "lost control of the drug". The Board also considered that the skilled person would have been able to discover the composition of the tablets without undue burden (note the recent referral to the EPO’s Enlarged Board of Appeal on this topic, see our article here).  As such, the Board concluded that the drug was made publicly available before the filing date, and the existence of the clinical trial was novelty destroying for a claim to an oral dosage form comprising the drug.  

Conversely, in the case underlying T670/20, patients were also permitted to take the drug tablets home, but in view of the protocol to which participants were requested to adhere, the patients were deemed to have entered "a special relationship" and therefore were not considered "members of the public" who could "freely dispose" of the tablets. In this case, the drugs were not considered to have been made available to the public, and claims to a pharmaceutical composition comprising the drug were considered novel. Clearly the way in which the trial is conducted is crucial to whether or not the conductance on the clinical trial itself will be citable as prior art. 

What this means for your filing strategy 

Applicants may be inclined to file as early as possible to ensure their claims are novel over the publication of a clinical trial protocol. However, as demonstrated in the EPO Board of Appeal decisions discussed in this article, basing a patent application on a clinical trial protocol that has already published is not necessarily fatal to the novelty of the invention. What’s more, the data obtained by conducting the clinical trial may be necessary to demonstrate to the EPO that the invention is sufficiently disclosed and involves an inventive step over the prior art.  Delaying filing, whilst certainly not without risk (and always should be done in the context of the global filing strategy), might allow those data to become available in time (for example, for inclusion in a PCT application). Watch this space, as we discuss this balancing act in further detail in the subsequent articles in this series. 

Of course, although the existence of a clinical trial protocol does not necessarily destroy the novelty of a claim to the use of the drug in treating disease at the EPO, such disclosures can be a larger obstacle for inventive step. Please stay tuned for our next article in this series, in which we will consider the EPO’s approach to inventive step relating to patent applications based on clinical trials, including how, despite the disclosure of a relevant clinical trail protocol, an inventive step might still be recognised. 

If you enjoy our series and have any related questions, please contact Tom Leonard, Juliette Howarth, or your usual Kilburn & Strode advisor. 

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