Conversion to lacosamide monotherapy in the treatment of focal epilepsy: results from a historical-controlled, multicenter, double-blind study

Randomized double-blind comparison of cognitive and EEG effects of lacosamide and carbamazepine

Differential effectiveness of antiepileptic drugs (AEDs) is more commonly determined by tolerability than efficacy. Cognitive effects of AEDs can adversely affect tolerability and quality of life. This study evaluated cognitive and EEG effects of lacosamide (LCM) compared with carbamazepine immediate-release (CBZ-IR). A randomized, double-blind, double-dummy, two-period crossover, fixed-dose study in healthy subjects compared neuropsychological and EEG effects of LCM (150mg, b.i.d.) and CBZ-IR (200mg, t.i.d.). Testing was conducted at screening, predrug baseline, the end of each treatment period (3-week titration; 3-week maintenance), and the end of each washout period (4weeks after treatment). A composite Z-score was derived for the primary outcome variable (computerized cognitive tests and traditional neuropsychological measures) and separately for the EEG measures. Other variables included individual computer, neuropsychological, and EEG scores and adverse events (AEs). Subjects included 60 healthy adults (57% female; mean age: 34.4years [SD: 10.5]); 44 completed both treatments; 41 were per protocol subjects. Carbamazepine immediate-release had worse scores compared with LCM for the primary composite neuropsychological outcome (mean difference=0.33 [SD: 1.36], p=0.011) and for the composite EEG score (mean difference=0.92 [SD: 1.77], p=0.003). Secondary analyses across the individual variables revealed that CBZ-IR was statistically worse than LCM on 36% (4/11) of the neuropsychological tests (computerized and noncomputerized) and 0% of the four EEG measures; none favored CBZ-IR. Drug-related AEs occurred more with CBZ-IR (49%) than LCM (22%). Lacosamide had fewer untoward neuropsychological and EEG effects and fewer AEs and AE-related discontinuations than CBZ-IR in healthy subjects. Lacosamide exhibits a favorable cognitive profile.

Long-term exposure and safety of lacosamide monotherapy for the treatment of partial-onset (focal) seizures: Results from a multicenter, open-label trial

OBJECTIVE

To assess long-term use and safety of lacosamide (LCM) ≤800 mg/day monotherapy in patients with partial-onset seizures (POS) enrolled previously in a historical-controlled, conversion-to-monotherapy study (SP902; NCT00520741).

METHODS

Patients completing or exiting SP902 with LCM as monotherapy or as adjunctive therapy were eligible to enter this 2-year open-label extension (OLE) trial (SP904; NCT00530855) at a starting dose ±100 mg/day of their final SP902 dose. Investigators could adjust the LCM dose to 100-800 mg/day and add up to two antiepileptic drugs to optimize tolerability and seizure reduction.

RESULTS

Three hundred twenty-two patients received LCM: 210 patients (65.2%) completed and 112 (34.8%) discontinued, most commonly owing to withdrawal of consent (9.3%). Two hundred fifty-eight patients (80.1%) had ≥1 year of and 216 (67.1%) had ≥2 years of LCM exposure, of whom 179/258 (69.4%) achieved LCM monotherapy lasting for any 12-month period, and 126/216 (58.3%) patients exposed for ≥24 months achieved LCM monotherapy for any 24-month period. Total exposure = 525.5 patient-years. The median modal dose was 500 mg/day. Two hundred ninety-two patients (90.7%) achieved LCM monotherapy at some point during the study. Sixty-five of 87 patients who exited and 193/235 who completed SP902 were exposed for ≥12 months, and 43.1% and 78.2%, respectively, achieved LCM monotherapy for ≥12 months. Median LCM monotherapy duration was 587.0 days (2-791 days); 91.0% of patients reported treatment-emergent adverse events, of which the most common were dizziness (27.3%), headache (17.1%), and nausea (14.3%). Compared with the SP902 study baseline, 74.2% of patients had a ≥50% seizure reduction and 5.6% were seizure-free at 24 months.

SIGNIFICANCE

The majority of patients were receiving LCM monotherapy at 0, 12, and 24 months in this OLE. Lacosamide monotherapy (median dose of 500 mg/day) had a safety profile similar to that of adjunctive therapy studies. These results support the use of lacosamide as long-term monotherapy treatment for adults with POS.

A long-term noninterventional safety study of adjunctive lacosamide therapy in patients with epilepsy and uncontrolled partial-onset seizures

This noninterventional, observational, postauthorization safety study (SP0942, NCT00771927) evaluated the incidence of predefined cardiovascular- (CV) and psychiatric-related treatment-emergent adverse events (TEAEs), in patients with epilepsy and uncontrolled partial-onset seizures, when initiating adjunctive therapy with lacosamide or another approved antiepileptic drug (AED) according to standard medical practice. Active recording of predefined TEAEs of interest took place at three-monthly recommended visits for up to 12months. Of 1004 patients who received at least one dose of adjunctive AEDs, 511 initially added lacosamide therapy, 493 added another AED, 69 were ≥65years of age, and 72 took concomitant antiarrhythmic drugs. Patients in the lacosamide cohort had a higher median frequency of partial-onset seizures (6.0 versus 3.5 per 28days) despite taking more concomitant AEDs (84.9% versus 66.9% took ≥2) at baseline. Patients who added lacosamide took a modal dose of 200mg/day over the treatment period (n=501), and 50.1% (256/511) completed 12months of treatment. Fifty-one point nine percent (256/493) of patients who added another AED completed the study, with the most commonly added AED being levetiracetam (28.4%). Four patients (0.8%) in each cohort, all <65years of age, reported predefined CV-related TEAEs. None were considered serious or led to discontinuation. One event each of sinus bradycardia (lacosamide), atrioventricular block first degree (lacosamide), and syncope (other AED) were judged to be treatment-related. Another patient in the other AED cohort reported bradycardia while taking concomitant antiarrhythmic drugs. Predefined psychiatric-related TEAEs were reported by 21 patients (4.1%) in the lacosamide cohort and 27 patients (5.5%) in the other AED cohort. Depression was the most common to be treatment-related (7/11 and 12/18 of patients reporting treatment-related psychiatric TEAEs, respectively). Serious psychiatric-related TEAEs were reported by four patients who added lacosamide (two cases of depression, two of suicide attempt) and one who added another AED (depression). Seven deaths occurred, all of which were considered unrelated/unlikely related to study medication. This thorough evaluation revealed a low incidence of predefined CV- and psychiatric-related TEAEs in patients taking adjunctive AED therapy according to standard medical practice. No specific safety concerns related to adjunctive lacosamide therapy were noted.

Conversion to eslicarbazepine acetate monotherapy: A pooled analysis of 2 phase III studies

Objective:

To assess the efficacy and safety of eslicarbazepine acetate (ESL) monotherapy.

Methods:

This post hoc pooled analysis of 2 randomized double-blind studies (093-045 and -046) included adults with partial-onset seizures medically uncontrolled by 1 or 2 antiepileptic drugs (AEDs). Following the baseline period (8 weeks), eligible patients were randomized 2:1 to receive ESL 1,600 mg or 1,200 mg once daily for 18 weeks; the primary endpoint was study exit by meeting predefined exit criteria (signifying worsening seizure control). In each study, treatment was considered effective if the upper 95% confidence limit for exit rate was lower than the historical control threshold (65.3%).

Results:

Pooled exit rates were as follows: ESL 1,600 mg = 20.6% (95% confidence interval: 15.6%–26.8%); ESL 1,200 mg = 30.8% (23.0%–40.5%). Use of 2 baseline AEDs or rescue medication, US location, epilepsy duration ≥20 years, and higher maximum baseline seizure frequency were associated with higher exit risks. Median percent reductions in standardized seizure frequency between baseline and the 18-week double-blind period were as follows: ESL 1,600 mg = 43.2%; ESL 1,200 mg = 35.7%; baseline carbamazepine use was associated with smaller reductions. Safety profiles were similar between ESL doses.

Conclusions:

Exit rates for ESL monotherapy (1,600 mg and 1,200 mg once daily) were lower than the historical control threshold, irrespective of baseline AED use and region, with no additional safety concerns identified. Clinical factors and location clearly influence treatment responses in conversion-to-monotherapy trials.

Classification of evidence:

This pooled analysis provides Class IV evidence that for adults with medically uncontrolled partial-onset seizures, ESL monotherapy is well tolerated and effective.

Repurposing historical control clinical trial data to provide safety context

Billions of dollars spent, millions of subject-hours of clinical trial experience and an abundance of archived study-level data, yet why are historical data underutilized? We propose that historical data can be aggregated to provide safety, background incidence rate and context to improve the evaluation of new medicinal products. Here, we describe the development and application of the eControls database, which is derived from the control arms of studies of licensed products, and discuss the challenges and potential solutions to the proper application of historical data to help interpret product safety.

Practical Use of Newer Antiepileptic Drugs as Adjunctive Therapy in Focal Epilepsy

This article lays the background for, and discusses the practical issues surrounding, the adjunctive use of the last four antiepileptic drugs (AEDs) to be licensed for the treatment of pharmacoresistant focal seizures in the UK and elsewhere. More than 30% of adolescent and adult patients will not be fully controlled on the currently available therapeutic armamentarium. After not responding to their first three AED schedules, only a handful of patients attained seizure freedom on subsequent regimens. To optimise the response to any new AED in this setting, it is often necessary to reduce the existing drug burden. The pharmacology, tolerability and safety, and everyday use of lacosamide, eslicarbazepine acetate, retigabine (ezogabine) and perampanel will be reviewed and discussed. This will be accompanied by data from prospective audits with each drug undertaken at the Western Infirmary in Glasgow, Scotland, and a report of their successful introduction in an illustrative case. Overall, there is a large variation in the course of refractory epilepsy and the effect of AED therapy on this process seems minimal. Nevertheless, a number of patients will benefit from the introduction of each new AED, with some becoming seizure-free.

Efficacy and safety of conversion to monotherapy with eslicarbazepine acetate in adults with uncontrolled partial-onset seizures: a historical-control phase III study

Background

Eslicarbazepine acetate (ESL, Aptiom®) is a once-daily (QD) anticonvulsant, approved as adjunctive treatment of partial-onset seizures (POS). It is extensively converted after oral administration to eslicarbazepine, and is believed to exert its effect through inhibition of voltage-gated sodium channels. The possible role of ESL as monotherapy to treat POS has not yet been established.

Methods

This study was an 18-week, multicenter, randomized double-blind trial of gradual conversion to ESL monotherapy in adults with POS not well controlled by 1–2 antiepileptic drugs (AEDs), using historical data as the control. The study comprised an 8-week baseline period, a 2-week titration period, a 6-week AED conversion period, a 10-week monotherapy period, and either a 1-week taper period or optional entry to an open-label extension study. The primary endpoint compared the Kaplan–Meier (KM)-estimated 112-day exit rate with a threshold value calculated from the historical controls.

Results

There were 172 randomized patients; 154 (90%) entered the AED conversion period and 121 (70%) completed the study. The KM-estimated exit rates [confidence interval (CI)] were 15.6% [8.1–28.7%] for ESL 1200 mg, and 12.8% [7.5–21.5%] for ESL 1600 mg. The upper limits of the 95% CI KM-estimates were below the pre-specified threshold for historical control of 65.3%, indicating that ESL was efficacious in reducing seizure-related exits, compared with historical control. During the 18-week double-blind treatment period, median reductions in standardized seizure frequency occurred with ESL 1200 mg (36.1%) and ESL 1600 mg (47.5%). The responder rates (a 50% or greater reduction in seizure frequency from baseline) during the 18-week double-blind period and the monotherapy period, respectively, were 35.2% and 38.9% for ESL 1200 mg, and 46.0% and 46.0% for ESL 1600 mg. The overall adverse event profile was consistent with the known safety profile of ESL.

Conclusions

These findings indicate that ESL monotherapy (1200 and 1600 mg QD) was efficacious and well tolerated in this study.

Trial registration

NCT01091662; EudraCT No. 2010-018684-42.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-015-0305-5) contains supplementary material, which is available to authorized users.

Efficacy and safety of conversion to monotherapy with eslicarbazepine acetate in adults with uncontrolled partial-onset seizures: a randomized historical-control phase III study based in North America

Objective

To assess the efficacy and safety of eslicarbazepine acetate (ESL) as monotherapy in North American patients with partial‐onset seizures (POS).

Methods

This multicenter, randomized, double‐blind “withdrawal to monotherapy” study used historical control data as the comparator. Adults with POS medically uncontrolled by one to two antiepileptic drugs gradually converted to ESL monotherapy. Following an 8‐week baseline period, patients were randomized 2:1 to receive ESL 1,600 mg (n = 128) or 1,200 mg QD (n = 65) for 18 weeks. The primary end point was the proportion of patients meeting predefined exit criteria (signifying worsening seizure control). Treatment was considered effective if the 95% upper confidence limit (UCL) for the Kaplan‐Meier estimated exit rate was lower than the exit rate threshold calculated from the historical control (65.3%).

Results

Kaplan‐Meier estimated exit rates were: ESL 1,600 mg, 28.7% (95% CI 21.2–38.1%) and 1,200 mg, 44.4% (32.5–58.3%). The difference between doses was not significant (p = 0.07). For both doses, the 95% UCLs for the exit rate were ˂65.3%; ESL monotherapy was considered superior to the historical control. There was no statistically significant increase in the risk of study exit related to carbamazepine use. Nine (7.6%) and five patients (8.3%) remained seizure‐free during the 10‐week monotherapy period, while taking ESL 1,600 and 1,200 mg, respectively. The reductions in median standardized seizure frequency (seizures per 28 days) between baseline and the 18‐week treatment period were: ESL 1,600 mg, 42% and 1,200 mg, 31%. Treatment‐emergent adverse events (TEAEs) occurring in ≥10% of patients were dizziness, headache, fatigue, somnolence, nausea, and nasopharyngitis. The TEAE most frequently leading to discontinuation was hyponatremia (2.1%).

Significance

ESL was efficacious and well tolerated as monotherapy in North American patients, and led to a reduction in seizure frequency. Exit rates for ESL 1,600 and 1,200 mg QD were superior to the historical control; the difference in exit rates between doses was not statistically significant.

Status epilepticus developing during lacosamide monotherapy

Two cases with partial onset epilepsy who developed status epilepticus (SE) on lacosamide (LCM) monotherapy are reported. LCM is an effective adjunctive antiepileptic drug (AED) for partial-onset epilepsy and as infusion in SE. It has also shown efficacy in monotherapy. The reported cases achieved control of seizures with adjunctive LCM treatment and were afterwards converted to monotherapy. Both patients subsequently developed SE while on LCM monotherapy. They were on monotherapy for at least 2 months after withdrawal of concomitant AEDs precluding the possibility of withdrawal-induced SE. Pharmacovigilance is indicated when LCM is administered in monotherapy in order to assess its proper therapeutic potential and its putative limitations especially in cases where it may prove ineffective. Moreover, vigilance is necessary whenever any concomitant antiepileptic is tapered regardless of the substances used. Higher doses may be needed when an AED is used in monotherapy.

The effects of lacosamide on depression and anxiety in patients with epilepsy

Depression and anxiety are common in patients with epilepsy. Moreover, some antiepileptic drugs (AEDs) have mood stabilizing and anxiolytic effects, while others may worsen psychiatric symptoms. The effects of lacosamide, a third generation AED approved for the treatment of focal onset seizures, on depressive and anxiety symptoms are unknown. We evaluated changes in depression and anxiety following the initiation of lacosamide. We compared patients' scores on the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E, n = 91) and Generalized Anxiety Disorder 7-item (GAD-7, n = 20) scales prior to and following lacosamide treatment. Following the initiation of lacosamide, there were no significant changes in NDDI-E scores when all patients were analyzed aggregately (baseline: 12.14 ± 4.64 vs post-treatment: 11.91 ± 4.14, p = 0.51). Similarly, the mean GAD-7 scores at baseline (4.10 ± 4.52) and after treatment (4.75 ± 5.51) did not differ (p = 0.23). In the 25 patients with initial NDDI-E scores of >15, lacosamide was associated with a significant decrease in depressive symptoms (baseline: 17.60 ± 1.63 vs post-treatment: 14.64 ± 2.78, p < 0.001). NDDI-E and GAD-7 scores pre- and post-lacosamide initiation were not significantly affected by a history of mood disorders, concomitant psychiatric medications, or concomitant AEDs with mood-stabilizing effects.

Lacosamide as adjunctive therapy in refractory epilepsy in adults: a systematic review

PURPOSE

To review the evidence for efficacy and safety of lacosamide in adult patients with refractory epilepsy and refractory status epilepticus (RSE).

METHODS

A systematic literature search of MEDLINE, PubMed, EMBASE, IPA, Google and Google Scholar (through October 2014) was performed.

RESULTS

Fourteen studies assessing lacosamide in 3509 refractory epilepsy patients were included. In 3 RCTs, more patients had at least 50% reduction in seizure frequency with lacosamide compared to placebo with 38.3-41.1%, 38.1-41.2%, and 18.3-25.8%, in the 400 mg/day, 600 mg/day, and placebo groups, respectively. In non-comparative trials, 18-69% of patients achieved at least 50% reduction in seizure frequency, and 1.7-26.2% achieved seizure freedom. Non-responders were documented in two trials, with 26.2-34% having no response. Thirteen studies assessing lacosamide in 390 RSE patients were included. When assessing lacosamide's ability to terminate RSE, one comparative cohort study found no improvement in SE duration or seizure control with addition of lacosamide. Another study documented no difference compared to use of phenytoin. Eleven descriptive studies using lacosamide as add-on RSE therapy revealed seizure termination rates of 0-100% (median 64.7%). In all patients receiving lacosamide, dizziness (21.8%), vision disturbances (10.4%), drowsiness (7.4%), headache (7.0%), nausea (6.5%), and coordination problems (5.8%) were the most common adverse effects.

CONCLUSION

Based on evidence to date, adjunctive lacosamide is a treatment option to reduce seizure frequency in patients with refractory epilepsy and terminate seizures in patients with RSE. The safety information summary can be used to advise patients of potential adverse effects.