Today, 26th March 2022, marks National Epilepsy Day, aimed at spreading awareness of this common, yet often mis-understood, neurological condition. In this blog, we explore the value for real-world evidence to support treatment decision making and ultimately improve patient outcomes for individuals with epilepsy.

What is epilepsy?

Epilepsy is one of the most common¹ neurological conditions in the world, one in every 100 people in the UK live with the condition². It is characterised by seizures caused by excessive electrical activity in the brain¹, diagnosis defined as having a minimum of two seizures of unknown origin occurring more than 24 hours apart. Seizures can cause a range of symptoms, from absence seizures (momentarily staring blankly, rapid blinking) to tonic-clonic seizures (a loss of consciousness, muscle jerks or spasms)³.

Although onset can occur at any age, distribution is known to be bimodal⁴, with incidence higher in children and adults over the age of 60. In children, cause is often linked to genetic abnormalities or developmental disorders². In adults, the prevalence of epilepsy is slightly higher in men compared to women and tend to peak in the elderly population, potentially due to higher frequency of stroke and neurodegenerative conditions in this age group⁵. However, in up to 70% of all cases, the cause of epilepsy is unknown⁶.

Treatment options for refractory epileptics: The value of real-world evidence

Uncontrolled, abrupt, and repetitive seizures can seriously affect quality of life. Seizure control for patients with epilepsy is primarily addressed with anti-epileptic drugs (AEDs)². AEDs are predominately prescribed by seizure type (generalised - where the whole region of the brain is impacted or focal – where seizures have affected a specific region).

Currently 30 anti-convulsant therapies⁷ (AED) are licensed in the UK, but despite this, around one third³ of patients are ‘refractory’ or ‘drug-resistant⁸ where seizures remain uncontrolled, regardless of treatment.

Expanding treatment options for refractory patients is an unmet medical need⁹. First line standard of care for refractory patients still include trials of various combination AED regimens until a potential successful treatment is identified, although clinical evidence has shown success rate for seizure control declines¹⁰ with each AED administered.

For refractory patients with focal onset seizures, tempol lobe surgery¹¹ is also a treatment option – the invasive nature of this surgery, however, carries high risks including serious cognitive impairment. Heterogeneity¹² of treatment response for this patient population further complicates the challenge to identify effective treatment.

Real world data is increasingly showing value to support research in this space.

A study conducted in 2018¹³, analysed longitudinal claims data from 2006 to 2015 and developed a model using machine learning to accurately predict patients at risk of drug-resistance following two rounds of AED therapy. Insights from real-world evidence such as this, have great potential to predict effective treatment options for refractory patients.

Characterised by recurrent febrile seizures, Dravet Syndrome is a rare form of refractory epilepsy that begins in infancy. A mutation in the SCN1A gene¹⁴ is present in approximately 80-90% cases¹⁵. Patients with Dravet Syndrome have an increased risk of sudden unexpected death in epilepsy (SUDEP) and an increased mortality rate of 7%-18%¹⁶.

Accurate early diagnosis of Dravet Syndrome is prominent as AED’s (specifically sodium channel agents) have shown to aggravate seizures¹⁷ and associated symptoms. Improvements in genetic testing has greatly improved this, however, more needs to be done.

In a recent real-world study¹⁸ for paediatric patients with Dravet Syndrome Fenfluramine, where hydrochloride proved a clinically significant reduction in seizure frequency.

Role of primary care in Epilepsy diagnosis

In the UK, primary care services play a crucial role in the adequate referral and initial diagnosis for epilepsy patients. Real world data collected from the primary care setting can further expand our understanding of this patient pathway.

IQVIA Medical Research Data (IMRD) incorporating data from THIN (a Cegedim database), includes de-identified electronic patient health record data from over 18 million patients collected from UK GP Practices. IMRD captures coded demographic, administrative data, clinical events, prescriptions, with secondary care and death information. IQVIA implement a wide variety of privacy-enhancing technologies and safeguards to protect individual privacy while maximising the utility of the data for medical research and treatment analysis.

A recent real-world study¹⁹ utilising IMRD assessed the burden on NHS healthcare resource use for children with epilepsy. The study concluded higher seizure frequency related to 11% more visits to GP’s, 35% more inpatient admissions, 15% more outpatient visits and increased direct HCRU costs by 24%.

An earlier study conducted in 2013²⁰ found a significant decline in incidence reporting for paediatric epilepsy in primary care between 1994 and 2008, supporting the need for an improved NHS approach to reporting of epilepsy diagnosis during this period.

For further information regarding the IQVIA Medical Research Data or other IQVIA real world data assets, please contact us.

References

¹ https://www.who.int/news-room/fact-sheets/detail/epilepsy

² https://www.epilepsy.org.uk/

³ https://www.epilepsy.com/learn/types-seizures

⁴ https://epilepsyresearch.org.uk/about-epilepsy/epilepsy-statistics/

⁵ https://www.karger.com/Article/Fulltext/503831

⁶ https://www.webmd.com/epilepsy/guide/epilepsy-causes

⁷ https://bnf.nice.org.uk/treatment-summary/epilepsy.html

⁸ https://www.frontiersin.org/articles/10.3389/fneur.2017.00301/full

⁹ https://www.dovepress.com/clinical-management-of-drug-resistant-epilepsy-a-review-on-current-str-peer-reviewed-fulltext-article-NDT

¹⁰ https://doi.org/10.3389/fneur.2017.00301

¹¹ https://www.medicalnewstoday.com/articles/epilepsy-surgery#can-surgery-help

¹² https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5068473/

¹³ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6461470/

14 https://rarediseases.info.nih.gov/diseases/10430/dravet-syndrome

15 https://rarediseases.org/rare-diseases/dravet-syndrome-spectrum/

16 https://onlinelibrary.wiley.com/doi/10.1111/epi.16690

17 https://www.discoveradventure.com/charities/dravet-syndrome-uk

18 https://onlinelibrary.wiley.com/doi/10.1111/epi.16690

19 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6837252/

20 https://adc.bmj.com/content/archdischild/98/3/195.full.pdf