Number needed to treat and associated cost analysis of cenobamate versus third-generation anti-seizure medications for the treatment of focal-onset seizures in patients with drug-resistant epilepsy in Spain

INTRODUCTION

Epilepsy is a serious neurological disease, ranking high in the top causes of disability. The main goal of its treatment is to achieve seizure freedom without intolerable adverse effects. However, approximately 40% of patients suffer from Drug-Resistant Epilepsy (DRE) despite the availability of the latest options called third-generation Anti-Seizure Medications(ASMs). Cenobamate is the first ASM approved in Spain for the adjunctive treatment of Focal-Onset Seizures (FOS) in adult patients with DRE. The introduction of a new drug increases the number of therapeutic options available, making it important to compare it with existing alternatives in terms of clinical benefit and efficiency.

PURPOSE

This study aimed to compare the clinical benefit, in terms of the Number Needed to Treat (NNT), and the efficiency, in terms of Cost per NNT (CNT), associated with cenobamate versus third-generation ASMs used in Spain for the adjunctive treatment of FOS in patients with DRE.

METHODS

The Number Needed to Treat data was calculated based on the ≥50% responder rate and seizure freedom endpoints (defined as the percentage of patients achieving 50% and 100% reduction in seizure frequency, respectively), obtained from pivotal clinical trials performed with cenobamate, brivaracetam, perampanel, lacosamide, and eslicarbazepine acetate. The NNT was established as the inverse of the treatment responder rate minus the placebo responder rate and was calculated based on the minimum, mid-range Daily Defined Dose (DDD), and maximum doses studied in the pivotal clinical trials of each ASM. CNT was calculated by multiplying the annual treatment cost by NNT values for each treatment option.

RESULTS

In terms of NNT, cenobamate was the ASM associated with the lowest values at all doses for both ≥50% responder rate and seizure freedom compared with the alternatives. In terms of CNT, for ≥50% responder rate, cenobamate was the ASM associated with the lowest CNT values at DDD and lacosamide and eslicarbazepine acetate at the minimum and maximum dose, respectively. For seizure freedom, cenobamate was associated with the lowest CNT value at DDD and the maximum dose and lacosamide at the minimum dose.

CONCLUSIONS

Cenobamate could represent the most effective ASM in all doses studied compared to the third-generation ASMs and the most efficient option at DDD for both ≥50% responder rate and seizure freedom. This study could represent an important contribution towards informed decision-making regarding the selection of the most appropriate therapy for FOS in adult patients with DRE from a clinical and economical perspective in Spain.

Determination of the economically justifiable price of cenobamate in the treatment of focal-onset seizures in adult patients with drug-resistant epilepsy in Spain

OBJECTIVE

To determine the economically justifiable price (EJP) of cenobamate to become a cost-effective alternative compared with third-generation anti-seizure medications in the treatment of focal-onset seizures (FOS) in adult patients with drug-resistant epilepsy (DRE) in Spain.

METHODS

Cost-effectiveness analysis comparing cenobamate with brivaracetam, perampanel, eslicarbazepine acetate and lacosamide. Markov model simulation of treatment pathway over a 60-year time horizon. Determination of effectiveness and quality-adjusted life-years (QALYs) of each health status, and disutilities associated with treatment-related adverse events. Acquisition costs and use of medical resources were obtained from published literature and expert opinion. Base-case of cenobamate's EJP calculated applying a willingness-to-pay (WTP) threshold of €21,000/QALY. Analyses performed at different thresholds, including dominant price scenario. Results robustness were assessed through sensitivity analyses.

RESULTS

Base-case shows that cenobamate's daily EJP of €7.30 is cost-effective for a threshold of €21,000/QALY. At a daily price of €5.45, cenobamate becomes dominant over all treatment alternatives producing cost-savings for the national health system (NHS). Sensitivity analyses supported the robustness of base-case findings.

CONCLUSIONS

Treatment with cenobamate produces incremental clinical benefit over third generation ASMs and at the base-case EJP could represent a cost-effective option for the adjunctive treatment of FOS in adult patients with DRE in Spain.

Cost-utility model of brivaracetam in the adjunctive treatment of patients with epilepsy in Spain

OBJECTIVE

This study aims to assess the cost utility of Brivaracetam compared with the third-generation anti-epileptic drugs used as standard care.

METHODS

A cost utility analysis of Brivaracetam was carried out with other third-generation comparators. The treatment pathway of a hypothetical cohort over a period of 2 years was simulated using the Markov model. Data for effectiveness and the QALYs of each health status for epilepsy, as well as for the disutilities of adverse events of treatments, were analyzed through a studies review. The cost of the anti-epileptics and the use of medical resources linked to the different health statuses were taken into consideration. A probabilistic sensitivity analysis was performed using a Monte Carlo simulation.

RESULTS

Brivaracetam was shown to be the dominant alternative, with Incremental Cost Utility Ratio (ICUR) values from -11,318 for Lacosamide to -128,482 for Zonisamide. The probabilistic sensitivity analysis validates these results. The ICUR sensitivity is greater for increases in the price of Brivaracetam than for decreases, and for Eslicarbizapine over the other adjunctives considered in the analysis.

CONCLUSIONS

Treatment with Brivaracetam resulted in cost effective and incremental quality adjusted life years come at an acceptable cost.

Need for pharmacoeconomic consideration of antiepileptic drugs monotherapy treatment in persons with epilepsy

Objective

Newer antiepileptic drugs (AEDs) are expected to have less adverse effects (AEs) and drug interactions as compared to conventional AEDs but the high cost is the major limitation for their use. This study evaluated variation in the cost of treatment with newer and conventional AEDs through its correlation with treatment efficacy and AEs in persons with epilepsy (PWE).

Methods

This cross-sectional study included PWE (28.9 ± 9.9 years) having focal and generalized seizures on conventional [valproate, carbamazepine, phenytoin] or newer AEDs [levetiracetam, oxcarbazepine] for >6 months. Seizure frequency during the study (6 months) was compared to that within 6 months before the study. Other parameters assessed were Quality of life in epilepsy, Pittsburgh Sleep Quality Index, Gastrointestinal Quality of life Index, and Liverpool AEs Profile. The cost of treatment was determined as direct, indirect, and intangible costs. The incremental cost-effectiveness ratio (ICER) analysis was also performed.

Results

Out of 214 PWE, 51.4% were on newer AEDs. Newer and conventional AEDs did not differ significantly in seizure frequency reduction (60.29 vs. 53.09%), quality of life parameters, though these were improved significantly during the study period. The direct medical cost and total cost of treatment were lesser with conventional AEDs (p < 0.001 in both) than newer AEDs, but the intangible cost did not differ. The total cost of treatment was significantly influenced by factors (as per regression analysis) including the type of AEDs (significant difference between valproate, carbamazepine, and levetiracetam), frequency of seizures, cost of medicine (70.34% of total cost), hospital admission, and treatment of AEs. As per ICER, newer AEDs need an additional USD 8.39 per unit reduction in seizure frequency.

Conclusion

Newer AEDs have comparatively better efficacy, though not significant than conventional AEDs. However, the additional cost per unit improvement is quite high with newer AEDs, necessitating pharmacoeconomic consideration in epilepsy treatment.

Construction of Pepstatin A-Conjugated ultrasmall SPIONs for targeted positive MR imaging of epilepsy-overexpressed P-glycoprotein

Surgical resection of the epileptogenic region is typically regarded to be practical and efficient for complete elimination of intractable seizures, which cannot be simply controlled by anti-epileptic drugs alone. To achieve a precision removal of the epileptogenic region and even a surgical cure, molecular imaging of epilepsy markers is highly essential for non-invasive accurate detection of the epileptogenic region. In this work, a peptide-targeted nanoprobe, based on ultrasmall superparamagnetic iron oxide nanoparticles (USPIONs), PA-USPIONs, was elaborately constructed to enable highly selective delivery and sensitive T₁-weighted positive magnetic resonance (MR) imaging of the epileptogenic region. Especially, Pepstatin A (PA), a small peptide which can specifically target to P-glycoprotein (P-gp) overexpressed at the epileptogenic region in a kainic acid (KA)-induced mice model of seizures, was conjugated onto the surface of PEGylated USPIONs. It has been demonstrated that the as-constructed PA-USPIONs nanoprobes have favorable T₁ contrast enhancement and high r₁ relaxivity compared with the clinically used T₁-MR contrast agent (Gd-DTPA) by systematic in vitro and vivo assessments. Importantly, the toxicity evaluation, especially to brains, was assessed by the histological as well as hematological examinations, demonstrating that the fabricated PA-USPIONs nanoprobes are featured with excellent biocompatibility, guaranteeing the further potential clinical application. This first report on the development of USPIONs as T₁-weighted MR contrast agents for active targeting of the epileptogenic region holds the high potential for precise resection of the according lesion in order to achieve therapeutic, often curative purposes.

Healthcare resource utilization and costs before and after lacosamide initiation as adjunctive therapy among patients with epilepsy in the United States

OBJECTIVE

The objective of this study was to evaluate all-cause and epilepsy-specific healthcare resource utilization and costs following lacosamide (LCM) initiation as adjunctive therapy for the treatment of epilepsy.

METHODS

A noninterventional retrospective database analysis was conducted that examined patients diagnosed as having epilepsy who added LCM to existing antiepileptic drug (AED) therapy between 2009 and 2016 (the first LCM prescription was the index event). This study used a single-case design whereby patients served as their own controls. Patients were further required to have a minimum of 12 months of continuous eligibility before (preindex period) and after (postindex period) their index event. In the 12-month postindex period, the only allowed AED regimen change was the addition of LCM. Demographic and clinical characteristics were measured at index and during the preindex period, respectively. All-cause and epilepsy-specific healthcare resource utilization and costs were measured and compared in the pre- and postindex periods. Paired t- and McNemar's tests were conducted to assess the significant differences between pre- and postindex. Univariate analyses were used to analyze the impact of LCM on specific subpopulations.

RESULTS

The study sample comprised of 2171 patients: mean (standard deviation [SD]) age: 38.9 (19.3) years; 52.6% female. Just over half (56%) of these patients were on monotherapy before adding LCM. Prior to adding LCM, 28.8% of patients had an epilepsy-specific inpatient (IP) admission, and 35.7% of patients had an all-cause IP admission, compared with 18.2% and 26.1% of patients in the post-LCM period, respectively (both p < 0.0001). Likewise, 35.6% of patients had an epilepsy-specific emergency room (ER) visit, and 50.0% had an all-cause ER visit prior to adding LCM, compared with 23.8% and 42.1% in post-LCM, respectively (both p < 0.0001). After adding LCM, one-year mean [SD] epilepsy-specific IP admission costs decreased by 42.9% ($13,647 [$52,290] to $7788 [$32,321]), and all-cause IP admission costs decreased by 38.6% ($20,654 [$72,716] to $12,688 [$46,120]) (both p < 0.0001). One-year epilepsy-specific mean [SD] ER costs decreased by 35.2% ($691 [$1756] to $448 [$1909]; p < 0.0001), and all-cause ER cost decreased by 17.8% ($1217 [$3014] to $1000 [$2970]; p < 0.01).

CONCLUSIONS

Epilepsy-related IP hospitalizations and ER visits (indicators of seizures) were significantly reduced in patients with epilepsy 12 months after adding LCM as an adjunctive therapy to existing AED treatment in a real-world setting, leading to reduced healthcare resource utilization and epilepsy costs.

Budget Impact Analysis of Brivaracetam Adjunctive Therapy for Partial-Onset Epileptic Seizures in Valencia Community, Spain

BACKGROUND AND OBJECTIVE

More than 30% of patients with epilepsy have inadequate control of seizures with drug therapy. The goal of this study is to determine the budget impact (BI) of the introduction of brivaracetam to the portfolio of approved drugs in Spain as adjunctive therapy for the treatment of partial-onset epilepsy in patients over 16 years old with a 5-year time horizon in the Valencia Community, a Spanish region with a population of 5 million.

METHODS

The BI model compares the pharmaceutical expenditure on antiepileptics in two scenarios: with and without brivaracetam. It assumes that the introduction and increased use of brivaracetam will lead to a proportional decrease in consumption of coexisting adjunctive antiepileptics and calculates the evolution of the consumption of brivaracetam over 5 years (2016-2020). The model was designed from the perspective of the Spanish National Health System. Data on the candidate population, consumption of antiepileptics, market share and pharmaceutical expenditure were obtained from real-world data. Finally, a sensitivity analysis was carried out on the set of variables involved in the evolution of costs using a Monte-Carlo simulation.

RESULTS

The model estimates that the target population eligible for adjunctive antiepileptics will hold at around 2352 between 2016 and 2020. Annual expenditure on antiepileptics is approximately €3.6 million. The number of patients eligible for treatment with brivaracetam would increase from 42 to 179 and annual savings of 0.09-0.37% would be created, representing €41,873 over 5 years (0.23% of the total budget). The sensitivity analysis corroborates that the probability of achieving savings with brivaracetam is around 84%.

CONCLUSIONS

Brivaracetam is a therapeutic alternative that allows savings for the health system in patients with non-controlled epilepsy in monotherapy, having a fixed, predictable annual cost (independent of dose) from the first day of treatment as the lack of need for titration means the patient is within a range of therapeutic doses from the first dose.

The cost effectiveness of newer epilepsy treatments: a review of the literature on partial-onset seizures

BACKGROUND AND OBJECTIVE

Epilepsy is one of the most common neurological disorders, affecting more than 3 million people in Europe. This paper reviews the published evidence regarding the cost effectiveness of second-generation antiepileptic drugs (AEDs).

METHODS

A systematic literature search was performed, using the databases Academic Search Complete, Econlit, EMBASE and MEDLINE. Health economic evaluations of newer (second-generation) AEDs, published as full-length journal articles, were searched for. We focused on evaluations of newer AEDs as treatment for partial-onset seizures. 470 studies were initially identified and 19 were finally included. Information regarding (i) AEDs studied, (ii) cost effectiveness, and (iii) a variety of health economic modelling specifics was extracted from each study. Then, the included studies were summarized and a quality assessment was performed, according to the British Medical Journal's guidelines for economic studies.

RESULTS

The results were as follows: (i) the cost per additional QALY for newer AEDs used as adjunctive treatment, compared with standard therapy, ranged between $US19 139 (levetiracetam) and $US57 210 (pregabalin) [year 2010 values]; no cost-effectiveness evidence was identified for felbamate, eslicarbazepine, oxcarbazepine or tiagabine; and (ii) all studies met at least 60% of the British Medical Journal's guidelines criteria, and seven studies were found to satisfy more than 80% of the criteria. Guidelines criteria not met involve inadequate reporting of input data and modelling details, including validation and availability of models used for cost-effectiveness calculations.

CONCLUSIONS

Although failure to meet good practice guidelines influences the reliability of the presented evidence adversely, a sufficient number of the included studies were found to comply enough with the guidelines in order for the qualitative content of the cost-effectiveness results - that some of the newer AEDs are cost effective - to be reliable. In fact, this conclusion is likely to be relatively robust, since the effect of improved seizure control on labour market performance was not included in the base-case results in any of the included studies and improved seizure control need only to have a moderate effect on sickness absenteeism in order for the corresponding treatment to be cost effective even when willingness to pay for an additional QALY is low. However, the cost effectiveness of newer AEDs has only been studied for a small number of settings, and hence future studies incorporating additional settings are needed.