Rapid Administration of Diazepam Results in Improved Seizure Cluster Cessation, Shorter Seizures

This article was originally published by NeurologyLive. It has been lightly edited.

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New post hoc data from a recently completed phase 3 trial (NCT02721069) assessing Neurelis' diazepam nasal spray (Valtoco), an FDA-approved antiseizure medication (ASM), indicated that faster time to administration was associated with shorter time to seizure cluster cessation and overall shorter seizure duration. Over a 12-month span, investigators also noticed a statistically significant change in SEIzure interVAL (SEIVAL), or the time between seizure clusters, that was independent of age of changes in concomitant ASMs.^1-3

These data were part of 2 poster presentations given at the 35th International Epilepsy Congress (IEC), held September 2-6, 2023, in Dublin, Ireland. In the first analysis, investigators assessed the temporal patterns of seizure clusters treated with diazepam nasal spray while the second characterized SEIVAL in treated individuals. Of the 175 enrolled patients ages 6 to 65 years, 163 received at least 1 dose of the therapy and 120 had SEIVAL data in period 1 and another period.

To characterize temporal patterns, seizure cluster data were analyzed based on the timing of treatment administration after seizure start: 0 to 5, 5 to 15, and more than 15 minutes. After excluding observations of seizure duration more than 24 hours, negative duration, and invalid dose date/time values, 3325 observations were included. In the 0- to 5-minute group, the median time from seizure start to administration of diazepam nasal spray, time from dosing to cessation, and total seizure duration, were 1, 2, and 4 minutes, respectively. In the 5- to 15-minute group, median times were 6, 7, and 15 minutes, respectively. Patients who received treatment after 15 minutes showed the least benefit, with median times of 35, 15, and 70 minutes, respectively.²

"Despite availability of chronic, daily oral medications to help control seizures, many patients continue to experience acute repetitive seizures," said Adrian L. Rabinowicz, MD, chief medical officer, Neurelis, in a statement.¹ "The clinical evidence presented at IEC further supports the utility of VALTOCO in acute seizure management to minimize the potential negative consequences of seizure clusters and have meaningful impact for people with epilepsy."

The second analysis evaluated SEIVAL across 4 consecutive 90-day periods, totaling 360 days, with paired t tests to assess statistical significance. In total, 76 patients had data in all 4 periods, representing a consistent cohort. In the general population, findings showed that from period 1 to 4, treated patients had mean SEIVAL increase from 14.8 to 35.8 days. In the consistent cohort, mean SEIVAL increased from 13.9 to 26.8 days (P ≤ .001).

Among a subgroup of pediatric participants ages 6 to 17 years (n = 32), mean SEIVAL increased from 13.0 to 25.9 days (P = .02). In adults (n = 44), mean SEIVAL increased from 14.6 to 27.5 days (P = .01). Notably, treatment with diazepam nasal spray resulted in increased mean SEIVAL among patients with (n = 56) changes in concomitant ASM therapy, going from 13.9 to 25.8 days, and those without (n = 20), increasing from 14.1 to 29.6 days. Investigators concluded that these findings may "reflect patient behavior or other factors, including a change in the underlying pathophysiology of seizure clusters."

The original phase 3 study, an open-label trial, included a 12-month treatment period, with study visits at day 30 and every 60 days thereafter, after which patients could elect to continue treatment. In total, 81.6% of patients were exposed to diazepam nasal spray for at least 12 months. Throughout the observed time, there was death because of sudden unexpected death in epilepsy and 1 withdrawal to a treatment-related AE, both considered unlikely to be related to treatment. Only 13 patients (7.9%) showed nasal irritation, and there were no relevant olfactory changes. The safety profile of diazepam nasal spray was generally similar across subgroups based on age, monthly usage, concomitant benzodiazepine therapy, or seasonal allergy/rhinitis.

References
1. Neurelis to present analyses of Valtoco (diazepam nasal spray) CIV highlighting effects on timing of seizures at the 35th International Epilepsy Congress. News release. Neurelis. August 31, 2023. Accessed September 6, 2023. https://www.prnewswire.com/news-releases/neurelis-to-present-analyses-of-valtoco-diazepam-nasal-spray-civ-highlighting-effects-on-timing-of-seizures-at-the-35th-international-epilepsy-congress
2. Misra SN, Jarrar R, Stern JM, Becker DA, Rabinowicz AL, Carrazana E. Faster time to treatment of seizure clusters with diazepam nasal spray is associated with faster cessation of clusters: a post hoc analysis. Presented at: 2023 International Epilepsy Congress; September 2-6; Dublin, Ireland. Abstract 243.
3. Misra SN, Sperling MR, Rao VR, et al. Significant improvements in SEIzure InterVAL (time between seizure clusters) across time: post hoc analysis of a long-term, open-label study of diazepam nasal spray. Presented at: 2023 International Epilepsy Congress; September 2-6; Dublin, Ireland. Abstract 655.
4. Wheless JW, Miller I, Hogan RE, et al. Final results from a phase 3, long-term, open-label, repeat-dose safety study of diazepam nasal spray for seizure clusters in patients with epilepsy. Epilepsia. 2021;62(10):2485-2495. doi:10.1111/epi.17041