Clinical trial medicine as prior art at the EPO

Pharmaceutical innovator companies increasingly have to consider the potential prior art effect of clinical studies carried out in order to gain approval of their medicines. The prior art effect may arise either from the clinical trial protocol being published online at, or it may arise because the trial patients took the medicine home with them and self-administered at home.

Decision T 7/07 found that in a phase 3 clinical trial, the patent proprietor had “lost control” of the study medicine and that, as a consequence, the trial patients constituted members of the public. Since the skilled person had the means to analyse the contents of the trial medicine available, it was concluded that the invention in question lacked novelty over the clinical trial.

Recent decision T 670/20 refers back to T 7/07 and provides more insight into when a clinical trial medicine may be considered available to the public (and when not). In the Catchword, the Board states:

The clinical trials were carried out in accordance with the EMEA Guidelines for Good Clinical Practice. These guidelines explicitly require adherence to the prescribed protocol and assurance of drug accountability. This set-up of the trials implies that the patients who decided to participate in the trials agreed, following their informed consent, to use the provided medication according to instruction or to return the unused medication.

Accordingly, the participating patients who were provided with the tablets under investigation entered into a special relationship with the investigators of the trials and were with regard to the provided tablets not members of the public that could freely dispose over these tablets.

In point 4.4 of the Reasons, the Board further explains that the freedom of the trial patients to discuss their participation in the clinical trial with their own physician, family, and friends is not at odds with their obligation to adhere to the study protocol and return unused drugs. The lack of “confidentiality” on the information received in order to give informed consent thus did not extend to the information that could only be extracted from the medicine per se.

This decision is encouraging for applicants and owners of pharmaceutical patents who wish to patent the result of a clinical trial.