Phantom Trials? On the Ambiguity of ‘Post’-Trial in Therapeutic Neural Device Trials

Amanda Merner, PhD – Massachusetts General Hospital; Ian Stevens, MA – The Hastings Center; Megan Wright, JD, PhD – Penn State Dickinson Law; Joseph Fins, MD, MACP, FRCP – Yale Law School; Gabriel Lázaro-Muñoz, PhD, JD – Massachusetts General Hospital

Abstract: Increasing regulatory attention has been given to ensuring participants in investigational medical device trials receive support after the trials end (i.e., ‘post trial’ access and support). Frameworks have emphasized mechanisms for continuing access, scaffolding routine clinical care, and distributing responsibilities among healthcare entities. However, while much post-trial discourse frames it as a discrete transition, our ongoing interviews with patients in therapeutic neural device trials suggests that when the ‘post-trial’ phase begins is often unclear.

Here, we present preliminary data from interviews with participants in deep brain stimulation (DBS) trials (n=10) as part of a broader project investigating post-trial support gaps. A seemingly straightforward question—”When did your trial end?”—proved unexpectedly difficult to answer. Many participants were unsure when, or even if, their trial had ended. This ambiguity is concerning, particularly as participants shared experiences reflective of unmet post-trial needs, such as unexpected costs for battery replacements or device repairs.

We describe this phenomenon as ‘phantom trials,’: a liminal phase where participants often retain some relationship with the research teams but without the formal protections of trial infrastructure. We argue for greater differentiation between various transition points in trials—such as when the trial officially begins, when access to the research team changes, or when financial coverage ends—to better understand and address shifting support needs. By more clearly mapping the transition points, we can build more translational frameworks and help better prepare participants to navigate these shifts as they occur.

Keywords: clinical trials, patient perspectives, neural devices