Real time monitoring of individual response to antiseizure medication treatment during clinical trials

Lead Investigator: Wesley Kerr, University of California, Los Angeles
Title of Proposal Research: Real time monitoring of individual response to antiseizure medication treatment during clinical trials
Vivli Data Request: 7161
Funding Source: None
Potential Conflicts of Interest: Dr. Stern is a consultant for UCB

Summary of the Proposed Research:

This analysis aims to use statistical theories to limit the time that participants in clinical trials take medications that they are assigned to. The goal of this would be to improve participant safety by reducing exposure to ineffective medications. Shortening the duration of trial participation also can improve trial efficiency.

While these theories can apply to many episodic conditions, we chose to explore these statistical theories in seizures. Seizures affect 3.4 million people in the United States alone. In addition to direct costs of healthcare for seizures, seizures have a profound impact on patient independence by limiting employment opportunities and mobility including driving. Unfortunately, despite many antiseizure medications, around 30% of patients with seizures continue to have seizures despite medications. Therefore, further clinical trials and more treatments are needed to improve the care of these patients.

To examine the benefits and limitations of our approach, we will apply our theories to actual clinical trial data to show how these trials could be done more efficiently where patients can have fewer seizures and be on ineffective treatments for less time. This benefits both the patient and the trial by reducing the time needed to monitor patients on each treatment. In our statistical design, we chose the Poisson process and negative binomial processes as models for seizures because prior literature has shown that they best match the time course of seizures recorded in seizure diaries.

Statistical Analysis Plan:

The pre-randomization seizure count will be modeled using Poisson and Negative Binomial statistics to make a Bayesian prior distribution for the estimate of seizure frequency on an individual-patient basis. For each day (or week) with reported seizure count, the post-randomization estimate of seizure frequency will be re-estimated. These two distributions will be compared to determine a likelihood that seizure frequency had reduced by 25, 50, or 75% on treatment. Actual treatment assignment or other confounding factors will not contribute to this estimate. Additional sensitivity analysis will include a ROC of certainty of non-response compared to sensitivity and specificity, the number of mandatory observation days prior to allowing treatment discontinuation, the influence of high or low pre-randomization seizure frequency, the influence of potential clustering of seizures, and optimal parameters in the Poisson and Negative Binomial models.

This statistical plan can be stated another way as follows. We will use individual-level, daily seizure counts to estimate the likelihood of response to the assigned treatment in the trial. We model seizure counts as Poisson or negative binomial processes. Based on this model, we will use a Bayesian approach to estimate the likelihood that seizure frequency has responded to treatment. Response will be defined as 25, 50, or 75% reduction in seizure frequency. When a participant’s likelihood of response is less than a threshold (e.g. 5% or 1%), we will simulate discontinuing participation in the trial. We will repeat the primary and secondary outcome analysis of the trial based on these truncated participation records to evaluate the effect of this early discontinuation on trial outcomes.

We will include all trials where individual-level seizure counts were available for patients at regular intervals prior to the completion of the trial. The ideal trial would include a daily seizure diary, but other acceptable reporting schemes include weekly seizure counts prior to completion of the trial. We also require reporting of individual-level baseline seizure count. In our paradigm, each individual patient’s seizure data is analyzed separately. This maintains the independence of individual trials. Due to our focus on improving trials overall, we will report statistics on an individual trial level, as well as a group level using meta-analysis techniques. For example, we will report the number of days spent on an ineffective treatment past when lack of efficacy was determined for each patient, as well as summary statistics by trial.

Due to the flexible nature of the duration of observation for each patient in our analysis, we will include all patients with data available from both the baseline period and the treatment period. If patients are lost to follow-up or otherwise discontinue participation in the trial, only data prior to discontinuation will be included. Missing data will not be imputed. For trials with titration periods, we will analyze data on each medication dose separately and keep the titration period separate from the treatment observation period.

Requested Studies:

A Randomized, Double-blind, Placebo-controlled, Multicenter, Parallel-group Study to Evaluate the Efficacy and Safety of Brivaracetam in Subjects (≥16 to 80 Years Old) With Partial Onset Seizures
Data Contributor: UCB
Study ID: NCT01261325
Sponsor ID: N01358

An International, Randomized, Double-blind, Parallel-group, Placebo-controlled, Flexible Dose Study: Evaluation of the Safety and Efficacy of Brivaracetam in Subjects (≥ 16 to 70 Years Old) Suffering From Localization-related or Generalized Epilepsy.
Data Contributor: UCB
Study ID: NCT00504881
Sponsor ID: N01254

A Multi-center, Double-blind, Parallel-group, Placebo Controlled, Randomized Study: Evaluation of the Efficacy and Safety of Brivaracetam in Subjects (>= 16 to 70 Years Old) With Partial Onset Seizures.
Data Contributor: UCB
Study ID: NCT00490035
Sponsor ID: N01252

An International, Double-blind, Parallel-group, Placebo-controlled, Randomized Study: Evaluation of the Efficacy and Safety of Brivaracetam in Subjects (>= 16 to 70 Years Old) With Partial Onset Seizures
Data Contributor: UCB
Study ID: NCT00464269
Sponsor ID: N01253

A Multicenter, Double-Blind, Randomized Conversion to Monotherapy Comparison of Two Doses of Lamotrigine for the Treatment of Partial Seizures
Data Contributor: GlaxoSmithKline
Study ID: NCT00355082
Sponsor ID: LAM30055

A Double-blind, Multicenter, Randomized, Placebo-controlled Study to Evaluate the Efficacy and Safety of Adjunctive Treatment With 3000 mg/Day (Pediatric Target Dose of 60 mg/kg/Day) Oral Levetiracetam (LEV) (166, 250, and 500mg Tablets), in Adult and Pediatric Subjects (4-65 Years) Suffering From Idiopathic Generalized Epilepsy With Primary Generalized Tonic-clonic (PGTC) Seizures.
Data Contributor: UCB
Study ID: NCT00160550
Sponsor ID: N01057

A Multicenter, Double-blind, Randomized, Parallel Group, Positive-controlled Trial Comparing the Efficacy and Safety of Levetiracetam (1000 to 3000 mg/Day Oral b.i.d.) to Carbamazepine (400 to 1200 mg/Day Oral b.i.d.), Used as Monotherapy for up to a Maximum of 121 Weeks in Subjects (≥ 16 Years) Newly or Recently Diagnosed as Suffering From Epilepsy, and Experiencing Partial or Generalized Tonic-clonic Seizures
Data Contributor: UCB
Study ID: NCT00150735
Sponsor ID: N01061

A Multicenter, Double-blind, Double-dummy, Randomized, Positive- Controlled Study Comparing the Efficacy and Safety of Lacosamide (200 to 600 mg/Day) to Controlled Release Carbamazepine (400 to 1200 mg/Day), Used as Monotherapy in Subjects (≥ 16 Years) Newly or Recently Diagnosed With Epilepsy and Experiencing Partial-onset or Generalized Tonic-clonic Seizures.
Data Contributor: UCB
Study ID: NCT01243177
Sponsor ID: SP0993

A Multicenter, Double Blind, Randomized, Placebo Controlled, Parallel Group Study to Investigate the Efficacy and Safety of Lacosamide as Adjunctive Therapy in Subjects With Epilepsy ≥4 Years to <17 Years of Age With Partial Onset Seizures
Data Contributor: UCB
Study ID: NCT01921205
Sponsor ID: SP0969

A Double-Blind Trial of Topiramate in Subjects With Lennox-Gastaut Syndrome.
Data Contributor: Johnson & Johnson
Study ID: NCT00236756
Sponsor ID: CR005464

A Randomised, Double-blind, Placebo-controlled, Parallel-group, Multicentre Study to Determine the Efficacy and Safety of 2 Doses of Retigabine Immediate Release (900 mg/Day and 600 mg/Day) Used as Adjunctive Therapy in Adult Asian Subjects With Drug-resistant Partial-onset Seizures.
Data Contributor: GlaxoSmithKline
Study ID: NCT01648101
Sponsor ID: RTG114855

A Multi-Center, Open-label, Randomized Study to Evaluate the Long Term Effectiveness of Levetiracetam as Monotherapy in Comparison With Oxcarbazepine in Subjects With Newly or Recently Diagnosed Partial Epilepsy
Data Contributor: UCB
Study ID: NCT01498822
Sponsor ID: N01367

A Randomized, Open-label, Parallel Group, Multi-center, Comparative, Phase IV Trial of Levetiracetam (LEV) Versus Topiramate (TPM) as Adjunctive Therapy to Evaluate Efficacy and Safety in Subjects With Refractory Partial Onset Seizures
Data Contributor: UCB
Study ID: NCT01229735
Sponsor ID: N01353

Topiramate Clinical Trial in Primary Generalized Tonic-Clonic Seizures
Data Contributor: Johnson & Johnson
Study ID: NCT00236704
Sponsor ID: CR005455

A Randomized, Double-Blind, Placebo-Controlled, Multicenter, Parallel-Group Phase 3 Study to Determine the Efficacy and Safety of Retigabine (1200 mg/Day) Used as Adjunctive Therapy in Refractory Epilepsy Patients With Partial-Onset Seizures
Data Contributor: GlaxoSmithKline
Study ID: NCT00232596
Sponsor ID: VRX-RET-E22-301

Topiramate (RWJ-17021-000) Monotherapy Clinical Trial in Patients With Recently Diagnosed Partial-Onset Seizures
Data Contributor: Johnson & Johnson
Study ID: NCT00230698
Sponsor ID: CR002503

A Multicenter, Double-blind, Randomized, Placebo-controlled, Parallel Group Trial to Investigate the Efficacy and Safety of SPM 927 (200mg/Day and 400mg/Day) as Adjunctive Therapy in Subjects With Partial Seizures With or Without Secondary Generalization
Data Contributor: UCB
Study ID: NCT00220415
Sponsor ID: SP0755

A Double-blind Trial Comparing the Efficacy, Tolerability and Safety of Monotherapy Topiramate Versus Phenytoin in Subjects With Seizures Indicative of New Onset Epilepsy
Data Contributor: Johnson & Johnson
Study ID: NCT00210782
Sponsor ID: CR004663

A Multicenter, Double-blind, Randomized, Placebo-controlled, Parallel Group Trial to Investigate the Efficacy and Safety of SPM 927 (400mg/Day and 600mg/Day) as Adjunctive Therapy in Subjects With Partial Seizures With or Without Secondary Generalization
Data Contributor: UCB
Study ID: NCT00136019
Sponsor ID: SP0754

A Randomized, Double-Blind, Placebo-Controlled, Fixed Dose-Ranging Study to Assess the Safety, Tolerability, and Efficacy of Topiramate Oral Liquid and Sprinkle Formulations as an Adjunct to Concurrent Anticonvulsant Therapy for Infants (1-24 Months of Age) With Refractory Partial-Onset Seizures
Data Contributor: Johnson & Johnson
Study ID: NCT00113815
Sponsor ID: CR002233

A Multicenter, Double-Blind, Randomized, Parallel-group Evaluation of LAMICTAL Extended-release Adjunctive Therapy in Subjects With Partial Seizures
Data Contributor: GlaxoSmithKline
Study ID: NCT00113165
Sponsor ID: LAM100034

A Multicenter, Double-blind, Randomized, Parallel-group Evaluation of LAMICTAL Extended-Release Adjunctive Therapy in Patients With Primary Generalized Tonic-Clonic Seizures
Data Contributor: GlaxoSmithKline
Study ID: NCT00104416
Sponsor ID: LAM100036

A Multi-Center, Double-Blind, Randomized, Placebo-Controlled, Parallel-Group Evaluation of Lamotrigine Adjunctive Therapy in Subjects Wtih Primary Generalized Tonic-Clonic Seizures
Data Contributor: GlaxoSmithKline
Study ID: NCT00043901
Sponsor ID: LAM40097

Valproate Dose Reduction and Its Clinical Evaluation by Introducing Lamotrigine in Japanese Women With Epilepsy – Single Arm, Multicenter, and Open-label Study
Data Contributor: GlaxoSmithKline
Study ID: NCT02100644
Sponsor ID: 200776

A Multicentre, Open-label, Long-term, Safety, Tolerability, and Efficacy Study of Retigabine Immediate-release (IR) in Asian Adults With Partial Onset Seizures (Extension of Study RTG114855)
Data Contributor: GlaxoSmithKline
Study ID: NCT01777139
Sponsor ID: 114873

A Multi-center, Uncontrolled, Open-label, Evaluation of Lamotrigine Monotherapy on Newly Diagnosed Typical Absence Seizures in Children and Adolescents
Data Contributor: GlaxoSmithKline
Study ID: NCT01431976
Sponsor ID: 115377

A Multi-center, Uncontrolled, Open-label, Evaluation of Lamotrigine Monotherapy in Newly Diagnosed Epilepsy or Recurrent Epilepsy (Currently Untreated)
Data Contributor: GlaxoSmithKline
Study ID: NCT01431963
Sponsor ID: 115376

A Multicentre, Open-Label, Long-Term, Safety and Tolerability Study of Retigabine Immediate Release (IR) in Adults With Partial-Onset Seizures (Extension of Study RGB113905)
Data Contributor: GlaxoSmithKline
Study ID: NCT01336621
Sponsor ID: 113413

Lamotrigine Extended-Release in Elderly Patients With Epilepsy
Data Contributor: GlaxoSmithKline
Study ID: NCT00516139
Sponsor ID: LEP105972

A Multicenter, Open-Label, Long-Term, Safety, Tolerability and Efficacy Study of Retigabine in Adult Epilepsy Patients With Partial-Onset Seizures (Extension of Study VRX-RET-E22-302)
Data Contributor: GlaxoSmithKline
Study ID: NCT00310388
Sponsor ID: VRX-RET-E22-304

A Multicenter, Open-label, Long-term, Safety, Tolerability and Efficacy Study of Retigabine in Adult Epilepsy Patients With Partial-onset Seizures (Extension of Study VRX-RET-E22-301)
Data Contributor: GlaxoSmithKline
Study ID: NCT00310375
Sponsor ID: VRX-RET-E22-303

An Open-label, Double Conversion Study to Characterize the Pharmacokinetics of Lamotrigine When Switching Patients With Epilepsy on LAMICTAL Immediate-release to Extended-release Formulation and Vice Versa
Data Contributor: GlaxoSmithKline
Study ID: NCT00264615
Sponsor ID: LEP103944

Randomized, Double-Blind, Placebo-Controlled, Multicenter, Parallel-Group Phase 3 Study – Determine Efficacy and Safety of Two Doses of Retigabine (900 Mg/Day and 600 Mg/Day) Used as Adjunctive Therapy in Refractory Epilepsy Patients With Partial-Onset Seizures
Data Contributor: GlaxoSmithKline
Study ID: NCT00235755
Sponsor ID: VRX-RET-E22-302

A Multicenter, Open-Label Conversion of Valproate Monotherapy to Lamotrigine Monotherapy in Patients With Epilepsy
Data Contributor: GlaxoSmithKline
Study ID: NCT00043914
Sponsor ID: LAM40013

Public Disclosures:

  1. Kerr W, Kok N, Reddy A, Stacey W, Stern J, Pennell P, French J. Time to event trial endpoints best measured efficacy when seizure counting started during maintenance excluding titration. American Epilepsy Society Annual Meeting. [See Abstracts tab]. Poster 1.285. 2023.
  2. Kerr W, Kok N, Reddy A, Stacey W, Stern J, Pennell P, French J. Time to prerandomization seizure count demonstrated efficacy of levetiracetam, lacosamide, lamotrigine, and brivaracetam with less placebo exposure. American Epilepsy Society Annual Meeting. [See Abstracts tab]. Poster 1.287. 2023.