Role of observational studies in supporting extrapolation of efficacy data from adults to children with epilepsy - A systematic review of the literature using lacosamide as an example

Extrapolation of efficacy data from adults to children is accepted for focal epilepsy - the antiepileptic drug, lacosamide, has been approved for the treatment of children ≥4 years of age on this basis. Since many small-scale, open-label studies are reported in the literature before approval, a systematic review was conducted to ascertain whether results of these could be used to support extrapolation in epilepsy in the future. In the absence of randomised trials, a second analysis was conducted for reports on lacosamide use in adults with generalized epilepsies. Twenty-seven articles were included in the paediatric qualitative synthesis, and 14 in the adult. Paediatric studies were analysed separately based on seizure type: focal, generalised and mixed. In focal epilepsy, safety and seizure-related findings mirrored those observed in the adult Phase II/III trials, supporting the feasibility of data extrapolation. Few studies reported outcomes in children with epilepsies associated with generalised seizures, and those that included children with different seizure types, mostly did not provide results separately. Lacosamide treatment appeared beneficial for children and adults experiencing tonic-clonic and myoclonic seizures. Reports of seizure aggravation were inconsistent and, in many cases, could not be clearly attributed to lacosamide. Given the absence of sufficient data, evidence for the feasibility of extrapolation was not as clear-cut as it was in focal epilepsy. These results highlight the complexities of conducting trials in the generalised epilepsy setting, and the importance of studies in the real-life setting and of analysing efficacy data per generalized seizure type and syndrome.

Comparative effectiveness of levetiracetam, valproate and carbamazepine among elderly patients with newly diagnosed epilepsy: subgroup analysis of the randomized, unblinded KOMET study

Background

Few clinical trials have evaluated the efficacy and tolerability of antiepileptic drugs (AEDs) as initial monotherapy for elderly patients.

Methods

This post-hoc subgroup analysis of data from an unblinded, randomized, 52-week superiority study (KOMET) compared the effectiveness of levetiracetam (LEV) with extended-release sodium valproate (VPA-ER) and controlled-release carbamazepine (CBZ-CR) as monotherapy in patients aged ≥ 60 years with newly diagnosed epilepsy. The physician chose VPA or CBZ as preferred standard treatment; patients were randomized to standard AEDs or LEV. The primary endpoint was time to treatment withdrawal. Results are exploratory, since KOMET was not powered for a subgroup analysis by age.

Results

Patients (n = 308) were randomized to LEV (n = 48) or VPA-ER (n = 53) in the VPE-ER stratum or to LEV (n = 104) or CBZ-CR (n = 103) in the CBZ-CR stratum. Mean age was 69.6 years, range 60.2–89.9 years (intention-to-treat population n = 307). Time to treatment withdrawal hazard ratio [HR] (95 % confidence interval [CI]) for LEV vs. standard AEDs was 0.44 (0.28–0.67); LEV vs. VPA-ER: 0.46 (0.16–1.33); LEV vs. CBZ-CR: 0.45 (0.28–0.72). Twelve-month withdrawal rates were: LEV vs. standard AEDs, 20.4 vs. 38.7 %; LEV vs. VPA-ER, 10.4 vs. 23.1 %; LEV vs. CBZ-CR, 25.0 vs. 46.6 %. Time to first seizure was similar between LEV and standard AEDs (HR: 0.92, 95 % CI: 0.63–1.35), LEV and VPA-ER (0.77, 0.38–1.56), and LEV and CBZ-CR (1.02, 0.64–1.63). Adverse events were reported by 76.2, 67.3, and 82.5 % of patients for LEV, VPA-ER, and CBZ-CR, respectively. Discontinuation rates due to AEs were 11.3, 10.2, and 35.0 % for LEV, VPA-ER, and CBZ-CR, respectively.

Conclusions

Time to treatment withdrawal was longer with LEV compared with standard AEDs. This finding was driven primarly by the result in the CBZ-CR stratum, which in turn was likely due to the more favorable tolerability profile of LEV. Results of this post-hoc analysis suggest that LEV may be a suitable option for initial monotherapy for patients aged ≥ 60 years with newly diagnosed epilepsy.

Trial registration

ClinicalTrials.gov: NCT00175903; September 9, 2005.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-016-0663-7) contains supplementary material, which is available to authorized users.

Addressing the treatment gap and societal impact of epilepsy in Rwanda--Results of a survey conducted in 2005 and subsequent actions

This study, supported by the Rwandan Ministry of Health and the World Health Organization, was conducted in 2005 to determine the prevalence of epilepsy and its sociocultural perception in Rwanda, as well as epilepsy-related knowledge and practices of health-care professionals (HCPs). A cross-sectional, nationally representative survey was conducted throughout Rwanda by trained investigators. Participants were recruited by random cluster sampling based on the organization of administrative units in the country. Overall, 1137 individuals (62% from rural areas) were interviewed. The prevalence of epilepsy was estimated to be 49 per 1000 people or 41 per 1000 for active epilepsy. Onset of epilepsy before the age of 2years was reported in 32% of the cases. Family history of epilepsy, head trauma, and premature delivery were reported in 53%, 50%, and 68% of the cases, respectively. Most (68%) patients did not receive any medical treatment for epilepsy; 21.5% had received some form of traditional treatment. According to responses from the general population, people with epilepsy should not be entitled to schooling (according to 66%), to work (according to 72%), to the use of public places (according to 69%), or to marriage (according to 66%). Furthermore, 50% believed that epilepsy was untreatable, and 40% thought that it was transmissible. Of the 29 HCPs interviewed, the majority knew the definition of epilepsy and status epilepticus, as well as basic treatment options and side effects. However, 90% believed that treatment was only necessary in the first week after a seizure. Living with epilepsy was associated heavily with stigma, and a significant treatment gap (68%) was identified. Following this study, numerous actions have been taken by the Rwandan government, the Rwandan League Against Epilepsy, and several nongovernmental organizations to increase awareness about epilepsy and to close the treatment gap. An overview of these activities is provided.

Measures for improving treatment outcomes for patients with epilepsy--results from a large multinational patient-physician survey

In this large-scale, multinational, descriptive survey, we sought to identify measures for improving treatment outcomes for individuals with epilepsy. As a framework, questions relating specifically to each of the five steps of the 'patient-physician journey', namely, patient identification (omitted in this survey), diagnosis, choice of drug, disease and drug information, and patient monitoring were asked. Overall, 337 physicians and 1150 patients across France, Germany, and the United States returned questionnaires. Results indicated that 16% of the patients were initially misdiagnosed. Treatment choice was driven by efficacy, safety, experience with a drug (physician only), and convenience (patient only). Physicians were identified as the primary source of information for patients, and, as expected, better informed patients were found to adhere better to their therapy than those who were less well informed. Approximately 50% of the patients had not seen their specialist in the last year, which indicates poor follow-up; furthermore, important topics such as seizures, treatment, and its side effects were not discussed at every visit. Specialists, but not primary care practitioners (PCPs), consistently reported discussing all topics more frequently than their patients, suggesting that specialists may overestimate the clarity of their questions. There was also substantial disparity in the reasons cited for nonadherence - patients overwhelmingly cited forgetfulness, while both PCPs and specialists cited complacency, forgetfulness, and tolerability. We also noted a disparity between physicians and their patients, as well as between PCPs and specialists, in their views on the impact of epilepsy on patients' lives. Our results indicate multiple opportunities to intervene at all stages of the patient-physician journey to improve treatment outcomes. We provide practical suggestions to achieve the most from these opportunities.

Excitation by dopamine of rat subthalamic nucleus neurones in vitro-a direct action with unconventional pharmacology

Recent anatomical and physiological studies have pointed to a functional innervation of the subthalamic nucleus by dopamine. This nucleus has a pivotal role in basal ganglia function and voluntary movement control and the possibility that dopamine, and dopaminergic medication used in Parkinson's disease, might directly influence its activity is of considerable interest. We have evaluated electrophysiologically the action and pharmacology of dopamine on single subthalamic neurones in rat brain slices. Dopamine increased firing rate to up to a mean of 60% in 98% of the 261 neurones tested when examined using extracellular single-unit recording. This excitation was unaffected by the GABA antagonist picrotoxin, and the glutamate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione, and persisted in a low Ca(2+)/raised Mg(2+) solution, indicative of a direct action, independent of synaptic transmission. Of the 33 cells examined using whole patch-clamp recording, only 13 showed measurable increases in firing rate and/or depolarisations in response to dopamine. Dopamine-responsive cells displayed significantly greater access resistance, suggesting that an unidentified cytoplamic constituent, removed by whole-cell dialysis, was required for the response. Using extracellular recording, the D2-like dopamine receptor agonists quinpirole and bromocryptine, but not the D1-like receptor agonist 1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol, also consistently caused an excitation. This was mimicked by the catecholamine releaser amphetamine in 60% of cells tested. However, the dopamine excitation was not significantly reduced either by the D1-like receptor antagonist 7-chloro8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine or the D2-like receptor antagonists (-)-sulpiride, eticlopride and (+)-butaclamol, and the quinpirole excitation was also unaffected by (-)-sulpiride. In contrast, (-)-sulpiride, eticlopride and (+)-butaclamol all abolished the D2-like receptor-mediated inhibition by dopamine of substantia nigra pars compacta neurones. The alpha-adrenoceptor antagonist phentolamine was a weak antagonist of dopamine excitations, but not of those caused by quinpirole. Dopamine excitations also showed weak sensitivity to the 5-HT(2) antagonist ritanserin, but were unaffected by the alpha(1)-adrenoceptor antagonist prazocin and the beta-adrenoceptor antagonist propranolol. The pharmacology of this dopamine excitation is inconsistent with an action on any known catecholamine receptor. However, the effect of amphetamine indicates that an unidentified monamine--possibly dopamine--can be released within the subthalamic nucleus to cause an excitation. The anomalies of its pharmacological characterisation do not strongly support a physiologically relevant direct action of dopamine in the rat subthalamic nucleus.