Drug Evaluation Committee 2014-52 Handling of Ascent in Psychiatric Diseases, etc.
Related classification: Obtaining consent
Date of first publication: April 2015
Question
In clinical trials for adult patients with dementia and other disorders, the sponsor may require the consent of both the subject and the surrogate (signature on the consent document) for all cases, If the study protocol clearly states that the subject is to be included in the trial with the consent of the surrogate, I have the impression that the subject's signature is not required.
If both the surrogate and the subject sign the consent document, is the subject's consent legally binding (is it treated as consent as in the case of children?) If the subject and the surrogate have different intentions to continue during the trial (e.g., the subject wants to stop, but the surrogate wants to continue), which will take precedence? Also, if the idea of informed consent is applicable to adults, do adult subjects need to have an assent document based on their comprehension?
Opinion of the Pharmaceutical Manufacturers Association of Japan (PMAJ)
In a clinical trial for adults with dementia, etc., asking the subject to sign the consent document along with the surrogate is in line with GCP Article 50, Paragraph 2/3, Guidance 2: "Provide explanations according to the capacity of the person to be the subject and, if possible, obtain the person to be the subject's signature and date on the consent document." We believe that this is in line with the following.
A substitute must be a person who can serve the best interests of the subject (GCP Article 2 Guidance 14), and "If it is difficult to obtain consent because the person who is to be the subject lacks the capacity to give consent, etc., the person who is to be the subject may be allowed to participate in the clinical trial by obtaining the consent of the person who is to be the substitute. and Article 50, Paragraph 2 of the GCP. Therefore, the legally valid consent is the consent of a surrogate. However, if the subject and the surrogate have different opinions during the course of the clinical trial, it is important for the surrogate to determine the necessity of discontinuation of the clinical trial after thorough consultation with the principal investigator, etc., taking into consideration the subject's intention, ability to understand, and other factors.
In "Guidance for Clinical Trials of Drugs in Pediatric Populations (December 15, 2000) 2.6.3," it is recommended to prepare an assent document to help pediatric subjects understand, but originally, the explanatory document for obtaining consent must use plain language as much as possible (GCP Article 51, Paragraph However, the explanatory document for obtaining consent must be as plain as possible (GCP Article 51, Paragraph 3), and therefore, an assent document for adult subjects is not envisioned. The final decision will be made by the investigator and the clinical trial review committee.
Reason for revision of opinion
Minor changes were made to the description in accordance with the issuance of GCP guidance (July 30, 2021, Pharmaceutical Affairs Bureau, Japan, No. 0705-3).