The European Medicines Agency (EMA) has recommended approving Kygevvi (doxecitine and doxribtimine) for use in the European Union, according to a recent press release. The medicine is for patients with a confirmed genetic diagnosis of thymidine kinase 2 deficiency (TK2d) whose symptoms began at age 12 or younger.
If the European Commission approves it, Kygevvi would be the first and only approved TK2d treatment in the European Union. Currently, TK2d care focuses on managing symptoms, such as using feeding tubes for nutrition, physical therapy to help with movement and ventilators to help with breathing.
Kygevvi was previously approved by the U.S. Food and Drug Administration (FDA) in November 2025 for individuals whose symptom onset occurred at or before age 12.
The EMA’s recommendation is based on data from medical records and a clinical study involving 39 people with TK2d whose symptoms began at age 12 or younger. After treatment with Kygevvi, 84% of patients regained at least one movement skill.
Read more about TK2d treatment and care
TK2d is caused by changes in the TK2 gene. This gene normally helps cells make the DNA of mitochondria, the parts of cells that make energy. When the gene does not work properly, mitochondria cannot produce enough energy. This leads to muscle weakness, trouble walking, breathing problems and a shorter life expectancy.
Scientists are not fully sure how Kygevvi works in people. However, studies in animals suggest that it helps improve the production of mitochondrial DNA in muscle cells and slows the disease.
This new development “is a significant step toward potential access to the first treatment option for TK2d in Europe,” said Caterina Garone, Associate Professor of Medical Genetics, University of Bologna, Italy.
A final decision is expected between April and June 2026.
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