Extrapolation of Efficacy from Adults to Pediatric Patients of Drugs for Treatment of Partial Onset Seizures (POS): A Regulatory Perspective

The FDA has concluded that the efficacy of drugs approved for the treatment of partial onset seizures (POS) in adults can be extrapolated to pediatric patients 1 month of age and above and that independent efficacy trials in this pediatric population are no longer needed. This manuscript focuses on the dosing, pharmacokinetic, exposure-response, and clinical information that were leveraged from the approved drugs for the treatment of POS to conduct analyses that supported extrapolation of efficacy in pediatric patients. Clinical data from trials for 8 drugs (levetiracetam, oxcarbazepine, topiramate, lamotrigine, gabapentin, perampanel, tiagabine, and vigabatrin) approved in both adults and pediatric patients for the treatment of POS were analyzed. Comparisons of exposures at approved doses, placebo response, and model-based exposure-response relationships were performed. Based on disease similarity, similar response to intervention, and similar exposure-response relationships in adults and pediatric patients, it was concluded that extrapolation of efficacy in pediatric patients aged 1 month and above is acceptable. PK analysis to determine pediatric dose and regimens that provide drug exposure similar to that known to be effective in adult patients with POS will be required, along with long-term open-label safety data in pediatric patients.

Association of genetic mutations and loss of ambulation in childhood-onset dystrophinopathy

BACKGROUND

Quantifying associations between genetic mutations and loss of ambulation (LoA) among males diagnosed with childhood-onset dystrophinopathy is important for understanding variation in disease progression and may be useful in clinical trial design.

METHODS

Genetic and clinical data from the Muscular Dystrophy Surveillance, Tracking, and Research Network for 358 males born and diagnosed from 1982 to 2011 were analyzed. LoA was defined as the age at which independent ambulation ceased. Genetic mutations were defined by overall type (deletion/duplication/point mutation) and among deletions, those amenable to exon-skipping therapy (exons 8, 20, 44-46, 51-53) and another group. Cox proportional hazards regression modeling was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Mutation type did not predict time to LoA. Controlling for corticosteroids, Exons 8 (HR = 0.22; 95% CI = 0.08, 0.63) and 44 (HR = 0.30; 95% CI = 0.12, 0.78) were associated with delayed LoA compared to other exon deletions.

CONCLUSIONS

Delayed LoA in males with mutations amenable to exon-skipping therapy is consistent with previous studies. These findings suggest that clinical trials including exon 8 and 44 skippable males should consider mutation information prior to randomization.

Multiple comorbid neuropathologies in the setting of Alzheimer's disease neuropathology and implications for drug development

Dementia is often characterized as being caused by one of several major diseases, such as Alzheimer's disease (AD), cerebrovascular disease, Lewy body disease, or a frontotemporal degeneration. Failure to acknowledge that more than one entity may be present precludes attempts to understand interactive relationships. The clinicopathological studies of dementia demonstrate that multiple pathologic processes often coexist.

How overlapping pathologic findings affect the diagnosis and treatment of clinical AD and other dementia phenotypes was the topic taken up by the Alzheimer's Association's Research Roundtable in October 2014. This review will cover the neuropathologic basis of dementia, provide clinical perspectives on multiple pathologies, and discuss therapeutics and biomarkers targeting overlapping pathologies and how these issues impact clinical trials.High prevalence of multiple pathologic findings among individuals with clinical diagnosis of AD suggests that new treatment strategies may be needed to effectively treat AD and other dementing illnesses.

Considerations for the assessment of suicidal ideation and behavior in older adults with cognitive decline and dementia

Introduction

Better understanding of suicide risk and its management in older adults with cognitive impairment and/or dementia remain significant unmet public health needs. Urgency to address them derives from concern that CNS treatments for dementia may impact suicide risk. Regulatory guidances requiring assessment of emergent suicidal ideation and behavior (SI/SB) at every clinical trial visit emphasize the need for understanding their prevalence.

Methods

The literature regarding SI/SB in older persons with cognitive impairment or dementia was reviewed by an Alzheimer's Association Taskforce with emphasis on epidemiology, classification, assessment, and regulatory requirements.

Results

Gaps in our knowledge were identified, challenges discussed and recommendations for future work provided.

Discussion

Currently available SI/SB data from geriatric persons with dementia do not provide adequate understanding of its epidemiology, identification, assessment, or management. The growing public health burden of this population requires greater attention from clinicians and researchers on tactics and assessment tools to meet these needs.

Psychiatric manifestations of neurologic disease: where are we headed?

Neuropsychiatry represents a field of medicine situated at the crossroads of neurology and psychiatry, and deals with the interface of behavioral phenomena driven by brain dysfunction. Psychiatric symptoms are highly prevalent in these conditions, are a major source of disability and diminished quality of life, and potentially represent the target of treatment interventions that stand to significantly decrease the suffering they generate. In this article, the disease paradigm is explained, with particular attention to its role as an organizing principle for the field. Specific diseases including traumatic brain injury, stroke, Parkinson's disease, Alzheimer's disease, multiple sclerosis, and epilepsy are explored in relation to the presentation of multiple psychiatric phenotypes in each, associations with underlying brain pathology, and existing treatment approaches. Finally, the afticle explores the inherent complexities in this area of research and proposes a framework for future work based on the understanding of phenomenology and associated risk factors, the involvement of the rapidly advancing field of neuroscience, and targeted treatment development to serve as a road map for advancement in the field.

Psychiatric manifestations of neurologic disease: where are we headed?

Neuropsychiatry represents a field of medicine situated at the crossroads of neurology and psychiatry, and deals with the interface of behavioral phenomena driven by brain dysfunction. Psychiatric symptoms are highly prevalent in these conditions, are a major source of disability and diminished quality of life, and potentially represent the target of treatment interventions that stand to significantly decrease the suffering they generate. In this article, the disease paradigm is explained, with particular attention to its role as an organizing principle for the field. Specific diseases including traumatic brain injury, stroke, Parkinson's disease, Alzheimer's disease, multiple sclerosis, and epilepsy are explored in relation to the presentation of multiple psychiatric phenotypes in each, associations with underlying brain pathology, and existing treatment approaches. Finally the article explores the inherent complexities in this area of research and proposes a framework for future work based on the understanding of phenomenology and associated risk factors, the involvement of the rapidly advancing field of neuroscience, and targeted treatment development to serve as a road map for advancement in the field..