Efficacy upon 12-weeks after achievement of maximal dose and tolerability of lacosamide as an adjunctive therapy in epilepsy: Real world clinical experience

Research Status, Synthesis and Clinical Application of Antiepileptic Drugs

According to the 2017 ILAE's official definition, epilepsy is a slow brain disease state characterized by recurrent episodes. Due to information released by ILAE in 2017, it can be divided into four types, including focal epilepsy, generalized epilepsy, combined generalized, and focal epilepsy, and unknown epilepsy. Since 1989, 24 new antiepileptic drugs have been approved to treat different types of epilepsy. Besides, there are a variety of antiepileptic medications under clinical monitoring. These novel antiepileptic drugs have plenty of advantages. Over the past 33 years, there have been many antiepileptic drugs on the mearket, but no one has been found that can completely cure epilepsy. In this paper, the mentioned drugs were classified according to their targets, and the essential information, and clinical studies of each drug were described. The structure-activity relationship of different chemical structures was summarized. This paper provides help for the follow-up research on epilepsy drugs.

Efficacy and tolerability of immediate switch from sodium channel blockers to Lacosamide

Lacosamide (LCM) is a new-generation anti-seizure medication approved for monotherapy and add-on therapy for focal-onset epilepsy. It has novel pharmacodynamics and favorable pharmacokinetic qualities with good clinical response. This study aims to evaluate the effectiveness and tolerability of LCM when used in the immediate switch from sodium channel blockers in patients with focal-onset and generalized-onset epilepsies. This retrospective, multicenter observational study was conducted with adult patients who received LCM as mono- or polytherapy through immediate switch with 6 to 52 months follow-up. The clinical data obtained during the follow-up period were analyzed to assess retention rate, seizure freedom, more than 50% seizure reduction, and adverse effects. A total of 32 patients (eight females, 24 males) with a median age of 49.75 (range, 23-86) years, median age at epilepsy onset of 32.58 (range, 0.5-85) years, and median epilepsy duration of 17.17 (range, 1-46) years were included in this study. Seizure frequency was between 1 and 90 in the past 6 months. Seven (21.9%) of the patients had structural brain lesions and 27 (84.4%) of the patients had EEG abnormalities. The adverse effects leading to switching were hyponatremia, rash, elevated liver enzymes, pain, and erectile dysfunction. At 14.34 (range, 6-52) months follow-up, 30 (93.75%) patients in total retained LCM, 20 (66.7%) of them were seizure-free, and 13 were on LCM monotherapy. Responder rate was 81.25%. Eight (25%) of the patients experienced adverse effects after the immediate switch. One patient with generalized-onset epilepsy needed to quit LCM due to an increase in seizures. Seizure frequency did not change in three patients in the focal-onset group. Immediate switch to LCM showed favorable outcomes with a significant reduction in seizure frequency, high retention rates, and tolerable adverse effect profiles in both focal-onset and generalized-onset seizures.

Twelve-Month Efficacy of Lacosamide Monotherapy at Maximal Dose and Tolerability for Epilepsy Treatment in Pediatric Patients: Real-World Clinical Experience

BACKGROUND

The efficacy and safety of lacosamide (LCM) monotherapy in Chinese pediatric patients with epilepsy have not been established. Therefore, this real-world retrospective study aimed to assess the efficacy of 12 months after achievement the maximal dose and tolerability of LCM as monotherapy for epilepsy treatment in pediatric patients.

METHODS

Pediatric patients were administered LCM monotherapy in two ways: primary or conversion monotherapy. Seizure frequency was recorded as an average per month for the preceding three months at baseline and then at each follow-up period for three, six, and 12 months.

RESULTS

Primary monotherapy with LCM was administered to 37 (33.0%) pediatric patients, whereas conversion to monotherapy was achieved in 75 (67.0%) pediatric patients. The responder rates of pediatric patients receiving primary monotherapy with LCM at three, six, and 12 months were 75.7% (28 of 37), 67.6% (23 of 34), and 58.6% (17 of 29), respectively. The responder rates of pediatric patients receiving conversion to monotherapy with LCM at three, six, and 12 months were 80.0% (60 of 75), 74.3% (55 of 74), and 68.1% (49 of 72), respectively. The incidence of adverse reactions with conversion to LCM monotherapy and primary monotherapy was 32.0% (24 of 75) and 40.5% (15 of 37), respectively.

CONCLUSION

LCM is an effective and well-tolerated treatment option as monotherapy for the treatment of epilepsy.

Therapeutic Drug Monitoring of Lacosamide in Chinese Pediatric Patients with Epilepsy: Efficacy and Factors Influencing the Plasma Concentration

BACKGROUND AND OBJECTIVE

The impact of individual patient variables on drug metabolism is particularly important for antiseizure medication, and lacosamide has not been studied in Chinese pediatric patients with epilepsy. This study evaluated the effects of dose, age, sex, medication time, seizure type, and concomitant enzyme-inducing antiseizure medications (EIASMs) on the plasma concentration of lacosamide.

METHODS

A total of 500 pediatric patients from two hospitals in China were enrolled in this study. Lacosamide plasma concentration was processed using an ultra-performance liquid chromatography assay. Efficacy was evaluated based on the four-grade therapeutic effect criteria developed by the first National Epilepsy Academic Conference of the Chinese Medical Association.

RESULTS

The responder rate to lacosamide therapy was 72.2% (361/500). There was a weaker relationship between the lacosamide daily dose and lacosamide plasma concentration (r = 0.238). Lacosamide plasma concentrations of patients ranged from 1.5 to 19.7 µg/mL, with a mean of 6.9 ± 3.2 µg/mL. The study results showed a significant contribution of age, body mass index, epilepsy duration, medication time, and EIASMs to the lacosamide plasma concentration (p < 0.05). Patients taking concomitant EIASMs with lacosamide had a significantly lower mean lacosamide plasma concentration (5.9 ± 2.6 µg/mL) than patients taking concomitant non-EIASMs (7.5 ± 3.5 µg/mL, p < 0.001).

CONCLUSION

To ensure the clinical efficacy and safety of lacosamide therapy in pediatric patients, it is necessary to monitor the plasma concentration.

Movement disorders associated with antiseizure medications: A systematic review

New-onset movement disorders have been frequently reported in association with the use of antiseizure medications (ASMs). The frequency of specific motor manifestations and the spectrum of their semiology for various ASMs have not been well characterized. We carried out a systematic review of literature and conducted a search on CINAHL, Cochrane Library, EMBASE, MEDLINE, PsycINFO, and Scopus from inception to April 2021. We compiled the data for all currently available ASMs using the conventional terminology of movement disorders. Among 5123 manuscripts identified by the search, 437 met the inclusion criteria. The largest number of reports of abnormal movements were in association with phenobarbital, valproic acid, lacosamide, and perampanel, and predominantly included tremor and ataxia. The majority of attempted interventions for all agents were discontinuation of the offending drug or dose reduction which led to the resolution of symptoms in most patients. Familiarity with the movement disorder phenomenology previously encountered in relation with specific ASMs facilitates early recognition of adverse effects and timely institution of targeted interventions.

Clinical impact of the dose and blood concentration of lacosamide in Japanese pediatric patients with epilepsy: A cohort study

PURPOSE

The relationship between treatment efficacy/tolerability and the dose/blood concentration of lacosamide (LCM) was investigated in a clinical cohort of Japanese pediatric patients with epilepsy.

METHODS

This retrospective analysis reviewed the medical records of patients treated with LCM for >6 months at the Department of Pediatrics, Hiroshima University Hospital, from September 2017 to January 2021. The collected data included age, sex, epilepsy type, seizure type, seizure frequency before and after treatment initiation, adverse events leading to LCM discontinuation, dose at any evaluation point, serum concentration, and concomitant antiepileptic drugs (AEDs).

RESULTS

The study included 51 patients (31 male patients) between the ages of 2 and 19 years. All patients were Japanese. Epilepsy was classified as focal in 44 patients, generalized in six patients, and combined generalized and focal in one patient. The 50% responder rate for LCM treatment was 56.9%. Seven patients experienced complete seizure control (absence of seizures for 6 months before the follow-up visit). A relationship between dose and blood concentration was identified. Although the blood LCM concentration was higher in the responders than in the nonresponders (7.86 vs. 6.16 μg/mL; p = 0.028), there was no significant difference in dose between the two groups. Lacosamide showed efficacy at a dose >5 mg/kg/day in more than half of the 50% responders. The treatment-emergent adverse events (TEAEs) included seizure aggravation in five patients, irritability in two patients, and somnolence and drug eruption in one patient each. In six patients with TEAEs, the TEAEs developed within 1 month after treatment initiation and led to LCM discontinuation.

CONCLUSION

In Japanese pediatric patients with epilepsy, LCM treatment is effective, particularly at higher doses. The blood concentration may be related more to efficacy than to dose. Lacosamide is generally well-tolerated by pediatric patients, and should be used at the maximum tolerable dose (needed to be gradually increased) in patients with otherwise insufficient seizure control. As TEAEs leading to discontinue treatment likely occur in early phase, it is needed to monitor patients carefully if TEAEs would happen in that phase.

A prospective, multicenter, noninterventional study in Taiwan to evaluate the safety and tolerability of lacosamide as adjunctive therapy for epilepsy in clinical practice

RATIONALE

Lacosamide (LCM) was initially approved in Taiwan in March 2014 for use as adjunctive therapy for focal impaired awareness seizures and secondarily generalized seizures (SGS) in patients with epilepsy ≥16 years of age. The efficacy and tolerability of adjunctive LCM for the treatment of patients with focal seizures have been demonstrated in randomized, placebo-controlled trials. However, the trials do not reflect a flexible dose setting. This study (EP0063) was conducted to assess the safety and tolerability of LCM in real-world clinical practice in Taiwan. Effectiveness of LCM was also assessed as an exploratory objective.

METHODS

EP0063 was a multicenter, prospective, noninterventional study with an expected observation period of 12 months ± 60 days. Eligible patients were ≥16 years of age, had focal impaired awareness seizures and/or SGS (in line with approved indication in Taiwan at the time of the study), were taking at least one concomitant antiseizure medication (ASM), and had at least one seizure in the 3 months before baseline. Patients were prescribed LCM by their treating physician in the course of routine clinical practice. The primary safety variable was treatment-emergent adverse events (TEAEs) spontaneously reported to, or observed by, the treating physician. Based on safety data from previous studies of LCM and known side effects of other ASMs, certain TEAEs (including but not limited to cardiac and electrocardiogram, suicidality, and rash related terms) were analyzed separately. Effectiveness variables included Clinical Global Impression of Change (CGIC) and change in 28-day seizure frequency from baseline to 12 months (or final visit), and freedom from focal seizures.

RESULTS

A total of 171 patients were treated with LCM, of whom 139 (81.3%) completed the study. The Kaplan-Meier estimated 12-month retention was 82.9%. Patients had a mean (standard deviation [SD], range) age of 38.5 (14.0, 16-77) years, and 96 (56.1%) were male. Patients were taking a mean (SD, range) of 2.8 (1.1, 1-6) ASMs at baseline. Mean (SD, range) duration of LCM treatment was 288.7 (111.9, 2-414) days, and the mean (SD, range) daily dosage of LCM was 205.0 (82.7, 50.0-505.2) mg/day. Overall, 95 (55.6%) patients reported at least one TEAE, most commonly dizziness (33 [19.3%] patients). Drug-related TEAEs were reported in 74 (43.3%) patients, and drug-related TEAEs leading to discontinuation of LCM were reported in 14 (8.2%) patients. Two (1.2%) patients died during LCM treatment, which were considered not related to LCM. Two (1.2%) patients had suicidality-related TEAEs; these TEAEs were considered either not related to LCM or the relationship was not recorded. Rash-related TEAEs were reported in five (2.9%) patients (considered LCM-related in two patients). Based on the CGIC, at 12 months (or final visit), 109 (63.7%) patients were considered to have improved, 54 (31.6%) had no change, and the remaining eight (4.7%) were minimally worse. At 12 months (or final visit), the median percentage change in focal seizure frequency was -50.0. During the first 6 months of the study, 21 (12.3%) patients were free from focal seizures; 37 (21.6%) patients were free from focal seizures in the last 6 months of the study; and 14 (8.2%) were free from focal seizures for the full 12 months of the study.

CONCLUSIONS

Results of this prospective, noninterventional study suggest that adjunctive LCM was generally safe and well tolerated in this patient group in real-world practice in Taiwan. Effectiveness was also favorable, with more than 60% of patients considered to be improved by their physician at 12 months (or final visit).