Novel design for a phase IIa placebo-controlled, double-blind randomized
withdrawal study to evaluate the safety and efficacy of CNV1014802 in patients
with trigeminal neuralgia.
Author(s): Zakrzewska JM(1), Palmer J, Ettlin DA, Obermann M, Giblin GM, Morisset V, Tate S,
Gunn K.
Affiliation(s): Author information:
(1)Facial pain unit, Division of Diagnostic, Surgical and Medical Sciences, Eastman
Dental Hospital, UCLH NHS Foundation Trust/University College London, 256 Gray's
Inn Road, WC1X 8LD, London, UK. j.zakrzewska@ucl.ac.uk.
Publication date & source: 2013, Trials. , 14:402
BACKGROUND: Trigeminal neuralgia (TN) is a rare severe unilateral facial pain
condition. Current guidelines in trigeminal neuralgia management recommend sodium
channel blockers--carbamazepine or oxcarbazepine--as the first-line treatment.
However, the currently available drugs are often associated with poor
tolerability resulting in sub-optimal pain control. CNV1014802 is a novel sodium
channel blocker that is being assessed in the treatment of trigeminal neuralgia.
Due to the severity of the condition, it is not ethical to conduct a traditional
placebo-controlled randomized controlled trial. It is also difficult to use an
active control such as carbamazepine, the current gold standard, because of its
complex pharmacology and potential for drug interactions.
METHODS/DESIGN: The trial uses a randomized withdrawal design to assess efficacy
in this rare condition. There is a 21-day open-label phase followed by a
randomized 28-day placebo-controlled phase for responders. Thirty patients will
be randomized. The primary outcome measure will be pain relief, but secondary
measures of quality of life will be of significant importance given the effect of
this condition on activities of daily living. Safety and adverse event endpoints
are described.
DISCUSSION: There have been very few well-controlled, randomized,
placebo-controlled studies in trigeminal neuralgia, and the majority of drugs
have had other primary uses. Due to the severity of the pain, minimizing the time
a patient is administered placebo was a key factor in designing this study. This
study will not only provide data on the efficacy of CNV1014802 in trigeminal
neuralgia, but will also provide information on the effectiveness and
acceptability of a novel trial design in trigeminal neuralgia.
TRIAL REGISTRATION: Trial number NCT01540630.
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