Stop Seizures – New anti-seizure treatment for drug-resistant epilepsy

Addressing the challenge of drug-resistant seizures

Epilepsy is the fourth most common neurological disorder, impacting 50 million individuals worldwide. Despite advancements in treatment, approximately 30% of patients do not respond to antiseizure medications – a statistic that has not significantly changed in the past century. This phenomenon results in healthcare costs for patients with drug-resistant seizures that are 2 to 4 times higher compared to those whose seizures are well-controlled.

Drug-resistant seizures significantly reduce a patient's quality of life, limit autonomy, and increase the risk of premature death, including Sudden Unexpected Death in Epilepsy (SUDEP). Furthermore, patients with drug-resistant seizures often require substantial support from caregivers and may encounter limitations in terms of employment opportunities, which can occasionally result in early retirement. This situation contributes to substantial indirect costs and has a considerable impact on society.

Research and development: Identification of potential new treatment

The Stop Seizures journey began in 1999 when the research team's principal investigator, Claudio Rivera, was first author on a seminal paper that demonstrated for the first time that KCC2 co-transporter is essential for establishing hyperpolarizing GABA A receptor-mediated inhibition – the primary mechanism of fast synaptic inhibition in the brain. In a healthy brain, there is a balance between excitation and inhibition signals just like a perfectly functioning gas and brake pedal in a car. KCC2 maintains this balance. However, in epilepsy, this balance is disrupted, resulting in excessive excitation and insufficient inhibition. This imbalance results in hyperactivity and seizures.

Market opportunities and applications: Expanding horizons for new medication, XlorAid

The epilepsy treatment market is projected to reach €16.4 billion by 2034, underscoring the demand for improved medications. Acute and prolonged seizures are medical emergencies with very few drugs available in the market and increased occurrences of drug resistance among patients. The Stop Seizure team is focusing on the acute seizure segment, where treatment options are currently limited. They will aim to enter the market with XlorAid. 

XlorAid is intended as a first-line treatment for acute seizures, with the potential to save up to €2 billion in healthcare costs each year in Europe and the USA, including those associated with treatment and hospital stays. This could significantly alleviate the financial burden on healthcare systems and improve patient outcomes.

Moreover, KCC2's role extends beyond epilepsy with XlorAid’s potential application in conditions such as neuropathic pain and developmental epileptic encephalopathies. This suggests significant commercial potential and opportunities for expansion, indicating a promising future for broader therapeutic applications.

Impact and benefits: precision in seizure treatment

XlorAid targets the KCC2 protein, which is specifically expressed in neurons. This approach allows the treatment to be much more precise, focusing on the areas of the brain directly affected by seizures.

Unlike current treatments, XlorAid uniquely targets diseased neurons, thereby minimising side effects such as dizziness and tiredness, which occur when healthy neurons are also affected. This precision makes XlorAid an effective treatment for seizures, and specifically for drug-resistant seizures, reducing the need for invasive surgery and significantly improving patients' quality of life.

In vivo experiments conducted by the Stop Seizures team have confirmed the efficacy of XlorAid. The drug candidate successfully crosses the blood-brain barrier and halts seizures in drug-resistant rodent models of temporal lobe epilepsy.

Future steps towards commercialisation

The project team is currently advancing their technology by optimising the drug-like properties of XlorAid. This development is supported by Business Finland's Research to Business funding, which the team received in early 2025.

As they refine XlorAid, the team is actively exploring commercialisation pathways and investment opportunities to facilitate its transition into the clinical stage. Collaboration with Contract Research Organisations (CROs) for preclinical assays and securing additional funding are pivotal steps in this process. Additionally, the team is diligently working on securing intellectual property rights to protect their innovation.