Confidentiality restrictions around clinical trials and prior public use (T 0670/20)

The recent Board of Appeal decision in T 0670/20 considered whether patients in a clinical trial were under conditions of confidentiality. The patent was for a tablet formulation that had been given to patients in a clinical trial conducted before the patent had been filed. The question became whether the patients could be considered members of the public, and whether their participation in the clinical trial therefore constituted prior public use of the formulation. 

Case background

The patent (EP 2140867) in T 0670/20 related to a tablet form of the anti-blood clot drug edoxaban (Lixiana, also known as DU-176b). The patent was opposed on the ground of, inter alia, lack of novelty in view of prior public use cited as the distribution of the tablets to patients in the phase IIa and IIb clinical trials for edoxaban (NCT00107900 and NCT00398216).

Critically, to satisfy the prior use test, it is not necessary to show that a disclosure has in fact taken place. It is a principle of novelty destroying prior art that it is only necessary for there to have been a potential disclosure to the public, the classic example of this being the unread thesis on the library shelf (IPKat). 

edoxaban tablets

The Opponent submitted that the skilled person, using common general knowledge, would have been able to determine the ingredients of the tablets used in the clinical trials for edoxaban. The Opponent further argued that the tablet, and therefore its ingredients, had been made available to the public during the course of the clinical trial. This was because the patients had been able to take the tablets home and, according to the Opponent, could not be considered under conditions of confidentiality for ethical reasons. As such, it was argued, the potential existed for the public to analyse and determine the formulation of the tablets. 

Confidentiality in clinical trials. 

The key question before the Board of Appeal was whether the patients were or were not under conditions of confidentiality. The Opponent argued that it would be unethical to prevent patients discussing the trial with their doctor and family. It was also pointed out that the clinical trial summaries themselves included guidance that, as a patient, you should "[t]alk with your doctor and family members or friends about deciding to join a study". 

The Board of Appeal, on the other hand, saw a distinction between confidentiality around the trial itself, and the tablets used in the trial. As such, a patient may have discussed the trial without disclosing information about the tablet itself. 

The Opponent had further argued that, whilst the patients were under an obligation to return unused tablets, not all unused tablets were in fact returned. For the Opponent, this demonstrated that the company had lost control of the product. Furthermore, it was argued that the lack of any legal sanction for not returning the tablets, meant that this requirement could not be considered legally equivalent to a confidentiality agreement. However, the Board of Appeal was not convinced by this argument. Instead, the Board of Appeal found that the patients could not be equated to members of the public free from conditions of confidentiality:

"the patients' agreement to use the provided medication according to instruction or to return the unused medication obliges the patient irrespectively [sic] of any sanction on non-compliance and therefore disqualifies the patients as members of the public with respect to the medication provided to them. The possibility of non-compliance to the instructed use and return of the tablets by participating patients does not affect the essence of this agreement" (r. 4.5)

The formulation was therefore found novel in view of the clinical trial summaries. The Board of Appeal also noted the difference in facts with the present case and that of T007/07. In T007/07 the patentee was found to have lost control of the drug product during the course of the clinical trial, as the tablets were handed out to members of the public not bound by confidentiality. 

Final thoughts

When running a clinical trial, preventing the accidental disclosure of confidential information can be an uphill battle. Clinical trial summaries, investor reports, and company announcements must all be reviewed and scrutinised to ensure there is no accidental disclosure of sensitive information before a patent application has been filed. The disclosure requirements stipulated by regulatory authorities are also increasing, most notably in Europe. All of this puts considerable pressure on companies to file patent applications for clinical inventions (such as dose and formulation), before clinical data can be obtained. In this context, the decision of the Board of Appeal at least provides some reassurance that patients in a clinical trial can be considered to be under conditions of confidentiality in a clinical trial. According to T 0670/20, the direct distribution of an investigative drug formulation to patients in a clinical trial thus does not necessarily constitute a public disclosure of the formulation. 

It is unclear from this decision, however, whether information about the drug product other than the formulation, such as the dose, would have been considered similarly confidential. If the patients were told the dose of the product, which they may then have discussed with their doctor and family (and which may also be observable), would this be considered a public disclosure? It is also worth noting that the decision rested very much on the facts of the case, and that, in contrast with T007/07, the patients could be considered under conditions of confidentiality in view of the way the trial itself was conducted. Trial design and patient communication is therefore another aspect to consider when ensuring details of a clinical invention are not prematurely and inadvertently disclosed. 

Further Reading

Proving the existence of confidentiality agreements and the celestial teapot - T 2037/18 (9 Dec 2019)

Mr Justice Nugee and the Superhose: The potentiality of disclosure (13 May 2019)

Hacon HHJ and the Seed Drill: Intentionality in prior use (Claydon v Mzuri, [2021] EWHC 1007) (27 April 2021)