FDA releases draft guidance on imaging endpoints

FDA released draft guidance on the recommended procedures for collecting and interpreting medical images in efficacy trials of drug or biologic candidates. The agency said the use of a centralized image reading facility is necessary when the imaging results determine trial eligibility, or the safety and efficacy of a drug candidate. Compared with separate image evaluation at each clinical site, the centralized process can better provide uniform reader training and management, ensuring that bias and variability are minimized, according to the draft. FDA did say site-based evaluations may be suitable in some instances, such as when the imaging technology is widely available, the image is easily assessed by a clinical radiologist and the drug candidate has shown little or no evidence of unblinding effects.

FDA added the timing of imaging evaluations depends upon the trial design, including the primary endpoint and the feasibility of the imaging schedule. The guidance noted that for time-to-event endpoints, evaluations should be conducted at baseline and at sufficient frequency to provide a reasonably precise measure of the time to the expected event. ...