%0 Clinical Trial, Phase III
%T Lack of observed tolerance to diazepam nasal spray (Valtoco®) after long-term rescue therapy in patients with epilepsy: Interim results from a phase 3, open-label, repeat-dose safety study.
%A Cascino GD
%A Tarquinio D
%A Wheless JW
%A Hogan RE
%A Sperling MR
%A Liow K
%A Desai J
%A Davis C
%A Rabinowicz AL
%A Carrazana E
%A
%J Epilepsy Behav
%V 120
%N 0
%D 07 2021
%M 33957437
%F 3.337
%R 10.1016/j.yebeh.2021.107983
%X Tolerance is a known consideration for maintenance use of benzodiazepines and other antiseizure drugs; however, clinical experience suggests that tolerance may not be anticipated with long-term intermittent use of benzodiazepines as rescue therapy. Diazepam nasal spray (Valtoco®) is a proprietary intranasal formulation approved for the acute treatment of intermittent, stereotypic episodes of frequent seizure activity (ie, seizure clusters, acute repetitive seizures) in patients with epilepsy aged ≥6 years. Reported here are exploratory analyses investigating whether there was evidence of development of tolerance in an interim analysis of a long-term, phase 3, open-label safety study of diazepam nasal spray.
Patients and care partners were trained to administer 5, 10, 15, or 20 mg of diazepam nasal spray (age- and weight-based dosing), with a second dose administered 4-12 hours later if needed. A series of analyses were performed to assess evidence of tolerance using 2 equal, adjacent time periods and data for each patient to compare the proportion of events for which second doses of diazepam nasal spray (as a proxy for effectiveness) were administered in period 1 compared with period 2.
A total of 175 patients were enrolled at interim cutoff, and 158 were treated with diazepam nasal spray for 3370 seizure-cluster events. For 73.4% of patients, duration of exposure to diazepam nasal spray was ≥12 months. A total of 191 analyses were conducted; the proportion of analyses in which second doses in period 2 were lower than in period 1 was 72.8%. Only 5 analyses showed nominally statistically significant changes (P < 0.05); this is fewer than expected by chance, and these differences were not directionally consistent. There was no safety signal with continued use.
These analyses found no statistical evidence of tolerance with the use of diazepam nasal spray over time based on use of a second dose in an initial period of the study compared with a subsequent period for each patient. These results are in agreement with prior studies of benzodiazepine rescue therapy.