A Multidisciplinary Recruitment Approach for The ExTINGUISH Trial: Identifying Successful Strategies to Increasing Eligible Participant Enrollment in a Rare Disease Clinical Trial

ObjectiveDescribe recruitment strategies to promote enrollment of patients with N-methyl-d-aspartate receptor (NMDAR)encephalitis in the ExTINGUISH Trial. BackgroundThe ExTINGUISH Trial is a phase-2B randomized, double-blind, placebo-controlled trial to evaluate the safety and efficacy of inebilizumab (300 mg) for the treatment of moderate-to-severe NMDAR encephalitis. Clinical trials for rare diseases frequently face recruitment difficulties, necessitating strategies to enhance participant enrollment. Design/MethodsThe ExTINGUISH Trial has implemented a multipronged recruitment approach to promote identification and enrollment of eligible patients with NMDAR encephalitis. Multidisciplinary teams are involved in study promotion and identification of trial-eligible patients, including NeuroNEXT Network Coordinating Centers, the Protocol PI team, and Site PIs and Program Managers. ResultsAs of April 2024, 34 patients have been enrolled in ExTINGUISH across 26 sites. The following recruitment strategies have been implemented at the international and national levels by the protocol study team: (1)Presentations at international and national conferences; (2)Grand Rounds education at all hospitals; (3)Launching of a 24/7 telephone hotline for suspected cases; (4)Inclusion of clinical trial details with reference lab results; and (5)Study promotion via the Neurology Podcast and Neurology Minute Daily Briefing, the American Academy of Neurology TV, and social media. At regional, state, and local levels, the following strategies have been implemented via a hub-and-spoke model: (1)Local site PI acts as a study champion; (2)Regional co-investigators are engaged as study champions at affiliated hospitals to identify and refer possible patients; (3)Promotion of the study at the state-level through presentation at state neurological society meetings; (4)Annually, obtaining a list from local facility of test send-outs and providers to send a personal, targeted outreach to ordering clinicians about the study. ConclusionsThe ExTINGUISH Trial multipronged approach to recruitment provides a selection of recruitment strategies that may improve outreach, recruitment, and retention of patients with rare diseases in future clinical trials.