Many clinical trials involve collecting tissues from trial participants as a part of the clinical protocol which inherently adds varying degrees of risk to the participants. The FDA has specified conditions under which biopsies could be collected and the processes involved to adequately control the amount, type, and quality of the tissue sample collected in compliance with good clinical practices (GCP) and good tissue collection practices (GTP) in its latest guidance document on this topic.
Biopsies are allowed when they are the only way to obtain data to determine eligibility or to evaluate the primary endpoint(s) or key secondary endpoint(s). In studies that involve collecting biopsies, it is a critical requirement for the participants as those who are unable to provide biopsies are excluded from the clinical trial. The FDA requires that in cases where biopsies are collected for future unspecified research purposes, they should be optional, and participants cannot be excluded for opting out of giving the biopsies described in the trial protocol.
The FDA requires that the sponsor describe the purpose of the biopsies and the associated risks in the clinical protocol. For invasive tissue collection sites, sponsors should consider alternative approaches to the biopsies, or provide a strong scientific justification for its critical need. Discussing this issue with the FDA in pre-submission meetings is very important in such cases. The guidance documents list 10 considerations and requirements for clinical protocols requiring the collection of biopsies from patients as a condition for inclusion into their study. The criteria are stricter for studies involving biopsies from pediatric participants.
Overall the guidance document describes common sense approaches for consideration by sponsors of clinical trials involving collection of tissue samples, specifically, those that involve invasive procedures.
