Charting the course: UCB's latest research on TK2d illuminates patient journeys

UCB is committed to understanding and addressing the unmet needs of patients living with thymidine kinase 2 deficiency (TK2d), an ultra-rare, life-threatening mitochondrial disease with a high mortality rate. According to a meta-analysis presented at the 2023 ISPOR conference, TK2d has an estimated prevalence of 1.64 per million people, with a range of 0.5 to 3.1 per million.  People living with TK2d face severe muscle weakness that can worsen over time and impact on activities as essential as walking, eating and breathing. To develop innovative solutions for TK2d, it’s crucial to understand the natural course of the disease, which is why we have focused on disease course research as part of our efforts to understand the landscape of TK2d care.
 

Understanding TK2d: a patient-centric approach
At the European Pediatric Neurology Society (EPNS) 2025 conference, we are proud to be able to share significant findings on the natural disease course of TK2d patients with symptom onset at or before 12 years of age, and qualitative work on patients lived experience, both highlighting UCB’s dedication to understanding patient experiences and outcomes through rigorous research.  The natural disease course study, funded by UCB, one of the first of its kind, is part of the largest international dataset on TK2d, providing crucial insights into the disease progression and disease burden impact on patients.

UCB presents qualitative narratives collected from a worldwide sample of patients and caregivers in a study that further illustrates the impact of TK2d on all aspects of an affected person's life.
 

The value of disease course studies
Disease course studies are important for ultra-rare conditions like TK2d because these conditions often lack sufficient research, understanding, and data due to their rarity. The study looked at those patients with early-onset TK2d (symptom onset 12 years and younger) and found the disease was associated with high mortality and rapid progression of the disease, with many experiencing critical motor skill loss and requiring ventilatory support within a short timeframe. Our survival analysis research also found that the median time from symptom onset to death was just 2.6 years for patients with an age of symptom onset of less than 12 years, highlighting the urgent need for improved management and care strategies.

The disease course study utilized a comprehensive disease course dataset involving two literature reviews of published case series, case reports and a retrospective chart review study of untreated patients, and another set of pre-treatment data from three UCB-sponsored clinical trials and data from UCB-supported expanded access programs (EAPs).

This approach ensured robust data collection and analysis to provide accurate depictions of the disease burden. By deepening the understanding of TK2d’s progression, UCB aims to inform better supportive care strategies for people living with the disease.
 

A holistic approach to patient care
These research efforts reflect UCB’s patient-first approach, which goes beyond treatment to holistically understanding the patient journey, ensuring that the voices and experiences of those living with TK2d are at the forefront of scientific advancement. By prioritizing patient needs and experiences, UCB strives to help address the unique challenges faced by TK2d patients and their families.

As we continue to explore new frontiers in TK2d research, UCB remains focused on delivering impactful solutions that empower patients and improve their quality of life. For more information on UCB’s initiatives and research in TK2d, visit UCB Stories.