Population Pharmacokinetics of Adjunctive Lacosamide in Pediatric Patients With Epilepsy

Lacosamide extended-release capsules are bioequivalent to lacosamide immediate-release tablets: Pharmacokinetic observations and simulations

OBJECTIVES

Assess the bioequivalence of lacosamide extended-release (XR) capsules and immediate-release (IR) tablets and answer real-world clinical questions regarding the use of lacosamide XR.

METHODS

An open-label, randomized, two-treatment, two-sequence, oral comparative bioavailability study was conducted to assess the bioequivalence of two lacosamide formulations. Participants were randomized 1:1 to receive lacosamide XR capsules (400 mg once-daily) or IR tablets (200 mg twice-daily) in 1 of 2 sequences over 7-day periods. Primary outcome was the area under the lacosamide concentration-time curve over 24 h at steady-state (AUC0-τ,ss). Secondary outcomes were maximum (Cmax,ss) and minimum concentrations at steady-state (Cmin,ss). Bioequivalence was established when 90% confidence intervals (CIs) for geometric least square means ratios (GLSMs) were between 80% and 125%. Adverse events (AEs) and other safety outcomes were also assessed. Pharmacokinetic simulations, including adherent and partially adherent dosing scenarios with XR and IR formulations, modeled the clinical use of lacosamide XR.

RESULTS

Thirty-five healthy adult males were enrolled in the bioequivalence study. After 7 days of study drug, mean AUC0-τ,ss, Cmax,ss, and Cmin,ss values were similar between XR and IR formulations; all 90% CIs for GLSMs were between 80% and 125%. AEs were mild and no serious AEs or other clinically significant safety findings were observed. Pharmacokinetic simulations suggested that partial adherence affected formulations similarly; and the best strategy for switching formulations was to take the morning lacosamide IR dose followed by the evening lacosamide XR dose, as this resulted in the most consistent lacosamide plasma concentrations.

CONCLUSIONS

Once-daily lacosamide XR capsules were bioequivalent to twice-daily lacosamide IR tablets. Pharmacokinetic simulations indicated lacosamide XR and IR formulations were similarly affected by partial adherence, though once-daily dosing with lacosamide XR may offer clinical advantages, and formulations can be easily switched. These results support the use of lacosamide XR capsules as a once-daily alternative to lacosamide IR tablets.

How to handle a missed or delayed dose of lacosamide in pediatric patients with epilepsy? a mode-informed individual dosing

This study aims to investigate the effects on the pharmacokinetic (PK) of lacosamide (LCM), and to guide the individual dosing regimens for children and ones with poor medication adherence. Population PK research was performed based on 164 plasma samples of 113 pediatric patients aged from 1.75 to 14.42 years old. The PK characteristic of LCM was developed by a one-compartment model with first-order elimination. The typical value of apparent clearance (CL) and apparent volume of distribution (Vd) was 1.91 L·h-1 and 56.53 L respectively. In the final model, the variability of CL was significantly associated with the body surface area (BSA) and elevated uric acid (UA) level. In contrast, the impact of some prevalent anti-seizure medicines, such as valproic acid, levetiracetam, oxcarbazepine, lamotrigine, and perampanel, and gene polymorphisms of Cytochrome P450 (CYP)2C19, ATP-binding cassette (ABC)B1, and ABCC2 had no clinical significance on the PK parameters of LCM. BSA-based dosing regimen of LCM was provided according to Monte Carlo simulation approach; while the dosage should reduce half in patients with an UA level of more than 400 μmol·L-1 comparing with an UA level of 100 μmol·L-1. Individualize remedial doses of about 0.5- to 1.5-fold of regular doses were recommended in six common scenarios of missed or delayed doses, that depended on the delayed time. In current study, the population PK model of LCM in children with epilepsy was developed successfully. The BSA-based dosing regimen and individualized remedial strategy were recommended to guarantee the precise administration of LCM.

Neonatal Cardiac Arrest Following Lacosamide Treatment: A Case Report

BACKGROUND

Lacosamide is an antiepileptic drug with US Food and Drug Administration approval for the treatment of partial-onset seizures in patients older than one month. Lacosamide works by selective enhancement of proteins that induce preferential slow promotion of sodium channels to the hyperpolarized inactive state. Lacosamide is generally well-tolerated; however, clinical and nonclinical studies have linked its use with cardiac side effects including PR prolongation and atrioventricular (AV) block.

RESULTS

We present the case of a three-week-old female neonatal patient born at 25 weeks' gestation who developed second-degree AV heart block and cardiac arrest after initiating lacosamide therapy. The patient was being treated for neonatal seizure complicated by intraventricular hemorrhage (grade II) and electrolyte disturbances with phenobarbital, levetiracetam, and phenytoin. Before addition of lacosamide therapy, the patient had an unremarkable electrocardiogram and no known cardiac risk factors for lacosamide. After medication discontinuation, the patient experienced no reoccurring episodes or other cardiac events.

CONCLUSION

Use of lacosamide for neonatal populations is currently under evaluation. This is the first report of adverse cardiac event (AV block) in the setting of neonatal lacosamide use. Risk of future adverse cardiac events should be evaluated when determining the safety and efficacy of lacosamide in the neonatal population.

Safety, tolerability, and efficacy of adjunctive lacosamide in pediatric patients with epilepsy syndromes associated with generalized seizures: Phase 2, open-label exploratory trial

OBJECTIVE

To evaluate the safety, tolerability, pharmacokinetics, and preliminary efficacy of lacosamide (LCM) (up to 12 mg/kg/day or 600 mg/day) as adjunctive therapy in pediatric patients with epilepsy syndromes associated with generalized seizures.

METHODS

Phase 2, multicenter, open-label exploratory trial (SP0966; NCT01969851; 2012-001446-18) of oral LCM for epilepsy syndromes associated with generalized seizures in pediatric patients ≥1 month to <18 years of age taking one to three concomitant antiseizure medications. The trial comprised a 6-week prospective baseline period, 6-week flexible titration period, and 12-week maintenance period.

RESULTS

Fifty-five patients (mean age: 9.2 years; 56.4% male) took at least one dose of LCM and had at least one post-baseline efficacy-related assessment. The median treatment duration was 127.0 days. There were no clinically significant mean or median changes or worsening from baseline to end of the titration period in the count of generalized spike-wave discharges per interpretable hour on 24-h ambulatory electroencephalogram recordings, or from baseline to the maintenance period in mean and median days with any generalized or focal to bilateral tonic-clonic seizures per 28 days. Treatment-emergent adverse events (TEAEs) were reported by 49 patients (89.1%), and three patients (5.5%) discontinued due to TEAEs. The median change and median percentage change in days with any generalized or focal to bilateral tonic-clonic seizures per 28 days from baseline to the maintenance period were both 0. Trends toward improvement (decrease) were observed in median change and median percentage change in days with each individual seizure type (absence, myoclonic, clonic, tonic, tonic-clonic, atonic, and focal to bilateral tonic-clonic) per 28 days.

SIGNIFICANCE

Safety findings were consistent with the known safety profile of LCM and were as expected for the pediatric population. There was no worsening of generalized seizures with LCM. Limitations include the inability to correlate spike and wave data with clinical outcomes, and the lack of similar studies against which the results can be compared.

Therapeutic drug monitoring of lacosamide among children: is it helpful?

Objective: This study aimed to investigate the efficacy and tolerability of Lacosamide (LCM) in a pediatric population with epilepsy using LCM serum concentration and its correlation to the age of the participants and the dosage of the drug. Methods: Demographic and clinical data were collected from the medical records of children with epilepsy treated with LCM at Shamir Medical Center between February 2019 to September 2021, in whom medication blood levels were measured. Trough serum LCM concentration was measured in the biochemical laboratory using High-Performance Liquid Chromatography (HPLC) and correlated with the administered weight-based medication dosing and clinical report. Results: Forty-two children aged 10.43 ± 5.13 years (range: 1-18) were included in the study. The average daily dose of LCM was 306.62 ± 133.20 mg (range: 100-600). The average number of seizures per day was 3.53 ± 7.25 compared to 0.87 ± 1.40 before and after LCM treatment, respectively. The mean LCM serum concentration was 6.74 ± 3.27 mg/L. No statistically significant association was found between LCM serum levels and the clinical response (p = 0.58), as well as the correlation between LCM dosage and the change in seizure rate (p = 0.30). Our study did not find a correlation between LCM serum concentration and LCM dosage and the gender of the participants: males (n = 17) females (n = 23) (p = 0.31 and p = 0.94, respectively). A positive trend was found between age and LCM serum concentrations (r = 0.26, p = 0.09). Conclusion: Based on the data that has been obtained from our study, it appears that therapeutic drug monitoring for LCM may not be necessary. Nonetheless, further research in this area is needed in the light of the relatively small sample size of the study.

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.

A prospective, real-world, clinical pharmacokinetic study to inform lacosamide dosing in critically ill patients undergoing continuous venovenous haemofiltration (PADRE-02)

AIMS

Although the use of continuous renal replacement therapy (CRRT) has increased, limited dosing information exists on the effect of CRRT on antiepileptic drug pharmacokinetics. The objectives of this practice-based study are to evaluate the pharmacokinetics of lacosamide and recommend individualized dosing recommendations in critically ill patients receiving continuous venovenous haemofiltration (CVVH).

METHODS

Seven patients receiving lacosamide and CVVH in a neurocritical care unit were enrolled. Pre-filter, post-filter and ultrafiltrate samples were obtained at baseline, right after the completion of the infusion, and up to six additional sampling time points post-administration. Patient-specific flow rates and clinical measures were also collected simultaneously at the time of sampling. Plasma concentrations were measured using a validated high-performance liquid chromatography with ultraviolet radiation detection (HPLC-UV) bioanalytical method. Non-compartmental analysis was utilized to characterize the pharmacokinetics of lacosamide.

RESULTS

The observed mean sieving coefficient for lacosamide was 0.80 ± 0.10, suggesting high removal of lacosamide. Concentrations measured in six out of seven patients were observed to be outside the therapeutic range (5-12 mg/L). The estimated average volume of distribution was found to be similar to healthy patients (0.58 L/kg). The mean bias and precision of the estimated total clearance was -2.53% and 14.9%, respectively. Simulations of various doses suggest that effluent flow rate-based dosing regimens could be used to individualize lacosamide therapeutics.

CONCLUSIONS

CVVH clearance contributed a major fraction of the total lacosamide clearance in neurocritically ill patients. Given that drug clearance increases with higher effluent flow rates, lacosamide dosing regimens should be increased to match exposures observed in patients with normal renal function.

Is Therapeutic Drug Monitoring of Lacosamide Needed in Patients with Seizures and Epilepsy?

Lacosamide is an antiepileptic drug (AED) that has linear pharmacokinetics, predictable blood concentrations, and few drug interactions, setting it apart from other AEDs that require vigorous therapeutic drug monitoring (TDM) such as phenytoin and carbamazepine. However, there have been reports of altered lacosamide pharmacokinetics in some populations. The purpose of this review is to determine whether lacosamide pharmacokinetics are altered in certain patient populations, suggesting the need for TDM. A literature search of Medline, Scopus, Embase, and Cochrane trials was conducted on January 3, 2019 (and then updated on September 2, 2019) to search for articles relevant to the TDM or pharmacokinetics of lacosamide. A total of 56 relevant articles were found and included in this review. Dose of lacosamide is linearly correlated with plasma concentrations and efficacy. However, currently there is no well-established reference range. Overall, the recommended reference ranges varied from 2.2 to 20 mg/L. Lacosamide has very few clinically relevant drug-drug interactions; however, there seems to be a significant drug interaction between lacosamide and enzyme-inducer AEDs. Based on available literature, it appears that lacosamide pharmacokinetics may be altered in severe renal dysfunction, in patients on dialysis and with extremes of age. More evidence is currently needed on lacosamide pharmacokinetics in pregnancy and critical illness. While it is not practical to utilize TDM for all patients, TDM may be useful in patients taking enzyme-inducer AEDs, in patients with decreased renal function or on dialysis, and older adults.

Use of Real-World Data and Pharmacometric Modeling in Support of Lacosamide Dosing in Pediatric Patients Under 4 Years of Age

The antiepileptic drug lacosamide (LCM) is approved in the United States and the European Union as monotherapy as well as adjunctive therapy for the treatment of focal seizures in children ≥4 years of age and adults. Using real-world therapeutic drug monitoring data, we performed a pharmacometric analysis for 315 pediatric patients (>1 month to <18 years of age) who received lacosamide as both monotherapy and adjunctive therapy. Population pharmacokinetic modeling was performed using nonlinear mixed-effects modeling with a 1-compartment structural model with linear elimination, where clearance and volume of distribution were allometrically scaled for body weight, with no further need for age-associated maturation functions. A covariate analysis for age, sex, race, and coadministration of other antiepileptic drugs identified phenobarbital and felbamate to significantly increase lacosamide clearance (1.71- and 1.46-fold, respectively). Based on the developed population pharmacokinetic model, simulations were performed in virtual pediatric patients to explore age-associated dose requirements to match lacosamide exposure in patient groups of different age with the exposure achieved in children ≥4 year of age with the weight-based dosing recommendations provided by the US Food and Drug Administration. Based on this approach, our analysis suggested that children ≥3 years of age needed the same dose as recommended by the US Food and Drug Administration for children ≥4 years of age (12 mg/kg/d), while children 1 to 3 years of age may need 13 to 14 mg/kg/d and infants between 1 month and 1 year of age may need 15 to 18 mg/kg/d (based on their actual age) to match the exposure seen in children ≥4 years of age.

Pharmacology of lacosamide: From its molecular mechanisms and pharmacokinetics to future therapeutic applications

Epilepsy is one of the most common brain disorders, affecting more than 50 million people worldwide. Although its treatment is currently symptomatic, the last generation of anti-seizure drugs is characterized by better pharmacokinetic profiles, efficacy, tolerability and safety. Lacosamide is a third-generation anti-seizure drug that stands out due to its good efficacy and safety profile. It is used with effectiveness in the treatment of partial-onset seizures with or without secondary generalization, primary generalized tonic-clonic seizures and off-label in status epilepticus. Despite scarcely performed until today, therapeutic drug monitoring of lacosamide is proving to be advantageous by allowing the control of inter and intra-individual variability and promoting a successful personalized therapy, particularly in special populations. Herein, the pharmacology, pharmacokinetics, and clinical data of lacosamide were reviewed, giving special emphasis to the latest molecular investigations underlying its mechanism of action and therapeutic applications in pathologies besides epilepsy. In addition, the pharmacokinetic characteristics of lacosamide were updated, as well as current literature concerning the high pharmacokinetic variability observed in special patient populations and that must be considered during treatment individualization.

Safety and tolerability of adjunctive lacosamide in a pediatric population with focal seizures - An open-label trial

PURPOSE

To evaluate safety and tolerability of adjunctive lacosamide in children with focal seizures.

METHODS

Patients were eligible for this open-label, fixed-titration trial (SP0847; NCT00938431) if aged 1 month-17 years with focal seizures taking 1-3 antiepileptic drugs. Findings from Cohort 1, aged 5-11 years, who received lacosamide ≤8 mg/kg/day, informed dosing for age-based cohorts 2-5, who then received ≤12 mg/kg/day (≤600 mg/day). Oral lacosamide was initiated at 2 mg/kg/day (1 mg/kg bid) and uptitrated by 2 mg/kg/day/week to the maximum cohort-defined dose (maximum trial duration: 13 weeks). Patients who did not achieve the maximum cohort-defined dose were discontinued.

RESULTS

Forty-seven patients (aged 6 months-≤17 years) enrolled (≥1 month-<4 years: n = 15; ≥4-<12 years: n = 23; ≥12-≤17 years: n = 9). 24/47 (51.1%) patients completed the trial at the maximum cohort-defined dose and 40/47 (85.1%) continued lacosamide in the extension trial. Treatment-emergent adverse events (TEAEs) were reported by 42/47 (89.4%) patients. The most common TEAEs (≥10% of patients) were vomiting (21.3%), diarrhea (14.9%), somnolence (12.8%), irritability, dizziness, and pyrexia (10.6% each). Twenty (42.6%) patients discontinued due to TEAEs, most commonly vomiting (8.5%), gait disturbance, dizziness, and somnolence (6.4% each). Six (12.8%) patients reported serious TEAEs, most commonly status epilepticus (3/47; 6.4%).

CONCLUSION

This fixed-titration trial supports the safety of adjunctive lacosamide in children (aged 6 months-≤17 years) with focal seizures. The TEAE profile was generally consistent with that observed in trials in adults, and no new safety concerns were identified.