Challenges recruiting to a proof-of-concept pharmaceutical trial for a rare disease: the trigeminal neuralgia experience

TY - JOUR

T1 - Challenges recruiting to a proof-of-concept pharmaceutical trial for a rare disease

T2 - the trigeminal neuralgia experience

AU - Zakrzewska, Joanna M

AU - Palmer, Joanne

AU - Bendtsen, Lars

AU - Di Stefano, Giulia

AU - Ettlin, Dominik A

AU - Maarbjerg, Stine

AU - Obermann, Mark

AU - Morisset, Valerie

AU - Steiner, Deb

AU - Tate, Simon

AU - Cruccu, Giorgio

PY - 2018/12/27

Y1 - 2018/12/27

N2 - BACKGROUND: This study aimed to describe recruitment challenges encountered during a phase IIa study of vixotrigine, a state and use-dependent Nav1.7 channel blocker, in individuals with trigeminal neuralgia.METHODS: This was an international, multicenter, placebo-controlled, randomized withdrawal study that included a 7-day run-in period, a 21-day open-label phase, and a 28-day double-blind phase in which patients (planned n = 30) were randomized to vixotrigine or placebo. Before recruitment, all antiepileptic drugs had to be stopped, except for gabapentin or pregabalin. After the trial, patients returned to their original medications. Patient recruitment was expanded beyond the original five planned (core) centers in order to meet target enrollment (total recruiting sites N = 25). Core sites contributed data related to patient identification for study participation (prescreening data). Data related to screening failures and study withdrawal were also analyzed using descriptive statistics.RESULTS: Approximately half (322/636; 50.6%) of the patients who were prescreened at core sites were considered eligible for the study and 56/322 (17.4%) were screened. Of those considered eligible, 26/322 (8.1%) enrolled in the study and 6/322 (1.9%) completed the study. In total, 125 patients were screened across all study sites and 67/125 (53.6%) were enrolled. At prescreening, reasons for noneligibility varied by site and were most commonly diagnosis change (78/314; 24.8%), age > 80 years (75/314; 23.9%), language/distance/mobility (61/314; 19.4%), and noncardiac medical problems (53/314; 16.9%). At screening, frequently cited reasons for noneligibility included failure based on electrocardiogram, insufficient pain, and diagnosis change.CONCLUSIONS: Factors contributing to recruitment challenges encountered in this study included diagnosis changes, anxiety over treatment changes, and issues relating to distance, language, and mobility. Wherever possible, future studies should be designed to address these challenges.TRIAL REGISTRATION: ClinicalTrials.gov, NCT01540630 . EudraCT, 2010-023963-16. 07 Aug 2015.

AB - BACKGROUND: This study aimed to describe recruitment challenges encountered during a phase IIa study of vixotrigine, a state and use-dependent Nav1.7 channel blocker, in individuals with trigeminal neuralgia.METHODS: This was an international, multicenter, placebo-controlled, randomized withdrawal study that included a 7-day run-in period, a 21-day open-label phase, and a 28-day double-blind phase in which patients (planned n = 30) were randomized to vixotrigine or placebo. Before recruitment, all antiepileptic drugs had to be stopped, except for gabapentin or pregabalin. After the trial, patients returned to their original medications. Patient recruitment was expanded beyond the original five planned (core) centers in order to meet target enrollment (total recruiting sites N = 25). Core sites contributed data related to patient identification for study participation (prescreening data). Data related to screening failures and study withdrawal were also analyzed using descriptive statistics.RESULTS: Approximately half (322/636; 50.6%) of the patients who were prescreened at core sites were considered eligible for the study and 56/322 (17.4%) were screened. Of those considered eligible, 26/322 (8.1%) enrolled in the study and 6/322 (1.9%) completed the study. In total, 125 patients were screened across all study sites and 67/125 (53.6%) were enrolled. At prescreening, reasons for noneligibility varied by site and were most commonly diagnosis change (78/314; 24.8%), age > 80 years (75/314; 23.9%), language/distance/mobility (61/314; 19.4%), and noncardiac medical problems (53/314; 16.9%). At screening, frequently cited reasons for noneligibility included failure based on electrocardiogram, insufficient pain, and diagnosis change.CONCLUSIONS: Factors contributing to recruitment challenges encountered in this study included diagnosis changes, anxiety over treatment changes, and issues relating to distance, language, and mobility. Wherever possible, future studies should be designed to address these challenges.TRIAL REGISTRATION: ClinicalTrials.gov, NCT01540630 . EudraCT, 2010-023963-16. 07 Aug 2015.

KW - Adult

KW - Aged

KW - Analgesics/adverse effects

KW - Double-Blind Method

KW - Europe

KW - Humans

KW - Middle Aged

KW - NAV1.7 Voltage-Gated Sodium Channel/drug effects

KW - Pain Measurement

KW - Patient Selection

KW - Rare Diseases/diagnosis

KW - Sample Size

KW - Sodium Channel Blockers/adverse effects

KW - South Africa

KW - Time Factors

KW - Treatment Outcome

KW - Trigeminal Nerve/drug effects

KW - Trigeminal Neuralgia/diagnosis

KW - Young Adult

U2 - 10.1186/s13063-018-3045-1

DO - 10.1186/s13063-018-3045-1

M3 - Journal article

C2 - 30587219

SN - 1745-6215

VL - 19

JO - Trials

JF - Trials

M1 - 704

ER -