UCB has announced that its Kygevvi (doxecitine and doxribtimine) has received a positive opinion from the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) for the treatment of thymidine kinase 2 deficiency (TK2d) in adults and children, with an age of symptom onset on or before 12 years.
The positive opinion recommends the granting of marketing authorisation under exceptional circumstances to Kygevvi. Authorisation under exceptional circumstances may be granted in cases where the rarity of the disease, or the difficulty of studying it, make the collection of full information about the treatment impossible. The final decision on Kygevvi is expected from the European Commission (EC) later in 2026.
The CHMP’s positive opinion is based on two studies of the treatment. The studies evaluated Kygevvi’s effect on survival, as well as on functional outcomes such as motor ability and the need for ventilatory and feeding support. The most common side effects of Kygevvi were gastrointestinal disorders.
TK2d is an extremely rare genetic mitochondrial disease that causes severe and progressive muscle weakness. The disease can affect activities such as walking, eating and breathing. Patients who experience symptom onset on or before the age of 12 are at high risk for premature death, which often occurs within three years of symptoms appearing.
Estimates suggest that there are 1.64 cases of TK2d per million people globally. Aside from supportive care, there is currently no approved treatment for the disease in Europe.
The EMA’s PRIority MEdicines (PRIME) scheme, which gives enhanced support to medicines that address unmet medical needs, supported the development of Kygevvi.
Caterina Garone, associate professor of medical genetics at the University of Bologna, Italy, said: “Doxecitine and doxribtimine treatment is a great example of how robust pre-clinical data can be translated into a clinical programme in ultra-rare disease, impacting the natural history of a fatal disorder such as TK2d.”
Donatello Crocetta, chief medical officer at UCB, added: “This positive CHMP opinion marks a turning point in the treatment of TK2d, offering a new chapter of hope and a meaningful step forward for patients, families and clinicians alike.”