Todd Grinnell

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.

Adjunctive eslicarbazepine acetate: A pooled analysis of three phase III trials

OBJECTIVE To assess the safety and efficacy of once-daily (QD) adjunctive eslicarbazepine acetate (ESL). METHODS This post-hoc pooled analysis of three randomized, placebo-controlled trials (2093-301, -302, -304) involved adults with refractory partial-onset seizures (POS) receiving 1-3 antiepileptic drugs (AEDs). All studies included 8-week baseline, 2-week titration, and 12-week maintenance periods. Patients were randomized equally to placebo, ESL 400mg (studies 301, 302), 800mg, or 1200mg QD. The primary endpoint was standardized seizure frequency (SSF; per 4weeks); secondary endpoints included responder rates (maintenance period), and incidence of treatment-emergent adverse events (TEAEs), TEAEs leading to discontinuation, serious AEs (SAEs), and deaths. RESULTS The safety and efficacy analysis populations totaled 1447 and 1410 patients, respectively. SSF was significantly reduced versus placebo with ESL 800mg (p=0.0001) and 1200mg (p<0.0001) but not 400mg (p=0.81). There were no significant interactions between treatment effect and age, gender, race/ethnicity, geographic region, epilepsy duration, or concomitant AED use. Incidences of TEAEs and TEAEs leading to discontinuation increased with ESL dose. Incidences of the most frequent TEAEs were lower for patients who initiated dosing at 400 versus 800mg QD, regardless of titration regimen and maintenance dose. SAE incidence was <10%; there were 3 deaths (placebo, n=2; ESL 800mg, n=1). CONCLUSIONS ESL (800 and 1200mg QD) was effective and well tolerated as adjunctive therapy for adults with refractory POS.

Evidence for a pharmacokinetic interaction between eslicarbazepine and rosuvastatin: Potential effects on xenobiotic transporters

INTRODUCTION Patients with partial-onset seizures and comorbid cardiovascular disease may concomitantly receive eslicarbazepine acetate (ESL), an antiepileptic drug, and rosuvastatin, an HMG-CoA reductase inhibitor. This study evaluated the effect of multiple-dose ESL on the pharmacokinetic (PK) parameters of a single dose of rosuvastatin in healthy subjects. METHODS This was a Phase I, single-center, fixed-sequence, open-label study. Healthy subjects received two treatments, in sequence. Treatment A: a single 40mg oral dose of rosuvastatin on Day 1, followed by a washout period (Days 1-4); treatment B: titration of ESL (400-800mg once daily) on Days 5-18, followed by ESL 1200mg once daily on Days 19-35, with a single dose of rosuvastatin (40mg) on Day 32. Subjects then entered a 2-week follow-up period. Plasma concentrations of rosuvastatin were quantified for PK analyses. Safety and tolerability were assessed throughout the study. RESULTS Thirty-three healthy subjects were enrolled and 30 completed the study. Mean rosuvastatin (standard deviation) t1/2 was similar when rosuvastatin was used concomitantly with ESL and when it was used alone (26.5 [16.3]h, and 22.4 [9.5]h, respectively). The geometric least squares mean ratios (90% confidence intervals) of rosuvastatin exposure levels between rosuvastatin used concomitantly with ESL and rosuvastatin used alone were as follows: Cmax, 64.0% (55.9-73.3%); AUC(0-∞), 63.0% (57.1-69.4%); and AUC(0-last), 60.9% (55.2-67.1%). Concomitant use of ESL and rosuvastatin was generally well tolerated. CONCLUSIONS Rosuvastatin exposure was 36-39% lower with steady-state administration of ESL, potentially due to reduced oral bioavailability of rosuvastatin. Consequently, when rosuvastatin is used with ESL, a rosuvastatin dose adjustment may be necessary if a clinically significant change in lipids is noted.

Influence of titration schedule and maintenance dose on the tolerability of adjunctive eslicarbazepine acetate: An integrated analysis of three randomized placebo-controlled trials

OBJECTIVE To examine the influence of titration schedule and maintenance dose on the incidence and type of treatment-emergent adverse events (TEAEs) associated with adjunctive eslicarbazepine acetate (ESL). METHODS Data from three randomized, double-blind, placebo-controlled trials were analyzed. Patients with refractory partial-onset seizures were randomized to maintenance doses of ESL 400, 800, or 1200mg QD (dosing was initiated at 400 or 800mg QD) or placebo. The incidence of TEAEs was analyzed during the double-blind period (2-week titration phase; 12-week maintenance phase), according to the randomized maintenance dose and the titration schedule. RESULTS 1447 patients were included in the analysis. During the first week of treatment, 62% of patients taking ESL 800mg QD had ≥1 TEAE, vs 35% of those taking 400mg QD and 32% of the placebo group; dizziness, somnolence, nausea, and headache were numerically more frequent in patients taking ESL 800mg than those taking ESL 400mg QD. During the double-blind period, the incidences of common TEAEs were lower in patients who initiated ESL at 400mg vs 800mg QD. For the 800 and 1200mg QD maintenance doses, rates of TEAEs leading to discontinuation were lower in patients who began treatment with 400mg than in those who began taking ESL 800mg QD. CONCLUSIONS Initiation of ESL at 800mg QD is feasible. However, initiating treatment with ESL 400mg QD for 1 or 2 weeks is recommended, being associated with a lower incidence of TEAEs, and related discontinuations. For some patients, treatment may be initiated at 800mg QD, if the need for more immediate seizure reduction outweighs concerns about increased risk of adverse reactions during initiation.

A WASO sub-group analysis of a 6-month study of eszopiclone 3 mg

BACKGROUND Insomnia marked by sleep maintenance difficulty is extremely prevalent. Yet, problems staying asleep have been relatively neglected as a research focus compared to problems falling asleep. Insomnia treatment studies typically have not required participants to have a problem specifically with sleep maintenance. It is possible that exclusion of such subjects limits the detection of treatment effects in the overall trial in general, and of effects on sleep maintenance specifically. In order to address these issues we conducted a post hoc analysis of a 6-month placebo-controlled trial in which there were no inclusion criteria that specified sleep maintenance difficulties to assess the variable effects of baseline wake time after sleep onset (WASO - the primary maintenance measure) on the efficacy of eszopiclone 3mg. METHODS Patients diagnosed with chronic primary insomnia were randomized to eszopiclone 3mg (n=593) or placebo (n=195) nightly for six months. The present analyses of this study consisted of: (1) determination of the distribution of baseline WASO; (2) continuous analysis of the relationship between baseline WASO severity and drug-placebo difference at month 1 and 6; and (3) categorical efficacy analyses of subgroups delimited by the following WASO thresholds: 0, 30, 45, 60, and 90 min. RESULTS The baseline WASO distribution was: ≤ 30=32.2%; >0 to ≤ 45=41.5%; >30 to ≤ 90=33.0%; >45 to ≤ 90=23.7%; >90=22.6%. A relationship between greater baseline WASO severity and a significantly greater drug-placebo difference in efficacy for WASO was evident in both continuous and categorical analyses. Eszopiclone was found to have significant sleep maintenance efficacy at each time point across the entire range of WASO severity studied. CONCLUSIONS As illustrated in this analysis, a significant proportion of chronic insomnia patients in efficacy trials that select on the basis of sleep onset latency and total sleep time criteria may have normative-range WASO. However, even in the subgroup with minimal WASO there was a significant sleep maintenance effect. The absence of any sleep maintenance effect in a drug trial may reflect the inclusion of relatively many insomnia patients with no baseline WASO abnormality. However, treatments with therapeutic effects on sleep maintenance, can still demonstrate improvement in sleep maintenance, even in a population not selected for this type of sleep problem, if adequately powered. Future clinical trials intending to examine sleep maintenance should employ WASO selection criteria that would ensure sufficient power to detect a sleep maintenance effect. Drug-placebo difference increased as a function of baseline WASO severity, suggesting that eszopiclones clinical effectiveness for insomnia may be enhanced in patients with more severe sleep maintenance symptoms.

Population Pharmacokinetics and Exposure–Response Analyses of Eslicarbazepine Acetate Efficacy and Safety in Monotherapy of Partial‐Onset Seizures

Eslicarbazepine acetate (ESL) is a once‐daily oral antiepileptic drug (AED) indicated for partial‐onset seizures (POS). ESL pharmacokinetics (PK) and exposure–response analyses were supported by 2 phase 3 conversion to ESL (1200, 1600 mg) monotherapy studies. The PK model development included 10 phase 1–2 studies (ESL 600–1200 mg daily). Seizure diaries were completed daily; subjects exited if seizures worsened. Exposure–response models were developed for time to study exit, probability of seizure freedom, time to first occurrence of dizziness, headache, and nausea; serum sodium levels were explored. A 1‐compartment model with first‐order absorption/elimination described ESL PK. Clearance and distribution volume were significantly related to body weight and sex. Higher eslicarbazepine minimum concentration (Cmin) and use of 1 baseline AED were associated with significantly lower risk of study exit, whereas eslicarbazepine Cmin was a significant predictor of seizure freedom during the last 4 weeks of monotherapy. Eslicarbazepine exposure and the time to first occurrence of adverse events were not related. A shallow negative relationship described the relationship between change from baseline in serum sodium level and eslicarbazepine exposure. Eslicarbazepine apparent clearance and distribution volume estimates were similar to those reported for ESL adjunctive therapy. Dose adjustment based on body weight was not required. The time to study exit and probability of seizure freedom during the last 4 weeks of monotherapy were weakly related to eslicarbazepine exposure. Because the first occurrence of adverse events or hyponatremia were also not significantly related to eslicarbazepine exposure, dose adjustment using plasma eslicarbazepine concentrations is not supported.

Effects of adjunctive eslicarbazepine acetate on serum lipids in patients with partial-onset seizures: Impact of concomitant statins and enzyme-inducing antiepileptic drugs

PURPOSE To evaluate the effects of eslicarbazepine acetate (ESL) on lipid metabolism and to determine whether reduced statin exposure during ESL therapy has clinical consequences. SUBJECTS AND METHODS We conducted a post-hoc analysis of pooled data for serum lipids (laboratory values) from three phase III, multicenter, randomized, double-blind, placebo-controlled trials of adjunctive ESL therapy (400, 800, or 1200 mg once daily) in patients with treatment-refractory partial-onset seizures. Changes from baseline in serum lipid levels were analyzed according to use of statins and/or enzyme-inducing antiepileptic drugs (EIAEDs) during the baseline period. KEY FINDINGS In total, 426 and 1021 placebo- and ESL-treated patients, respectively, were included in the analysis. With regard to the changes from baseline in serum concentrations, there were statistically significant differences between the placebo and ESL 1200 mg QD groups, for both total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C), but the effect sizes were small (+4.1 mg/dL and +1.8 mg/dL, respectively). A small but significant difference in low-density lipoprotein cholesterol (LDL-C; -5.0 mg/dL) was observed between the ESL 400 mg QD group and the placebo group. In patients not taking a concomitant EIAED, there were no changes with ESL 400 mg QD, but modest and statistically significant increases in cholesterol fractions (TC, LDL-C and HDL-C) with ESL 800 mg QD (<6 mg/dL) and ESL 1200 mg QD (<10 mg/dL). ESL had no consistent effect on lipids in patients taking a concomitant EIAED. In patients taking statins during baseline, there were no clinically relevant changes in serum lipids during use of ESL, although the subgroups were small. SIGNIFICANCE These results suggest that ESL does not appear to have clinically significant effects on serum lipids, nor does the pharmacokinetic interaction between ESL and statins have an impact on serum lipid concentrations.

Efficacy and safety of eslicarbazepine acetate monotherapy in patients converting from carbamazepine.

To evaluate the influence of prior use of carbamazepine (CBZ) and other antiepileptic drugs (AEDs) with a putatively similar mechanism of action (inhibition of voltage‐gated sodium channels; VGSCs) on seizure outcomes and tolerability when converting to eslicarbazepine acetate (ESL), using data pooled from 2 controlled conversion‐to‐ESL monotherapy trials (studies: 093‐045, 093‐046).

Exposure-safety and efficacy response relationships and population pharmacokinetics of eslicarbazepine acetate

Eslicarbazepine acetate (ESL) is a once‐daily (QD) oral antiepileptic drug (AED) for focal‐onset seizures (FOS). Pharmacokinetic (PK) and pharmacodynamic (PD) models were developed to assess dose selection, identify significant AED drug interactions, and quantitate relationships between exposure and safety and efficacy outcomes from Phase 3 trials of adjunctive ESL.

Exploratory Biomarker Study of the Triple Reuptake Inhibitor SEP‐432 Compared to the Dual Reuptake Inhibitor Duloxetine in Healthy Normal Subjects

SEP‐432 is a triple monoamine reuptake inhibitor of norepinephrine (NE), serotonin (5‐HT), and dopamine (DA), based on in vitro binding studies. We sought evidence that SEP‐432 engages these monoamine systems by measuring concentrations of monoamines and/or their main metabolites in cerebrospinal fluid (CSF) and plasma and comparing results to duloxetine, a dual reuptake inhibitor of NE and 5‐HT.