UCB wins CHMP favour for first thymidine kinase 2 deficiency treatment

The European Medicines Agency (EMA)’s human medicines committee has recommended approval of the first treatment for thymidine kinase 2 deficiency (TK2d) in Europe.

The Committee for Medicinal Products for Human Use (CHMP)’s granted its positive opinion of UCB’s Kygevvi (doxecitine and doxribtimine) under exceptional circumstances in individuals with symptom onset at or before 12 years of age.

Donatello Crocetta, Chief Medical Officer at UCB, said: “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.”

The CHMP’s decision is supported by data from two studies, a phase II single arm clinical study and a retrospective chart review and (1, 2) in these patients.

According to UCB, animal studies suggest that the pyrimidine nucleosides doxecitine and doxribtimine lower TK2 activity and help delay disease progression by improving the production and maintenance of mitochondrial DNA.

The ultra-rare genetic mitochondrial disease causes progressive and severe muscle weakness (myopathy) and in Kygevvi’s phase II study 84 percent of patients regained one or more motor milestones.

Caterina Garone, Associate Professor of Medical Genetics, 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 thymidine kinase 2 deficiency.

“The CHMP positive opinion is a significant step toward potential access to the first treatment option for TK2d in Europe.”

The regulator’s opinion is based on the condition that UCB conducts a new study to confirm the safety and efficacy of Kygevvi, prior to the European Commission (EC)’s final decision on approval of the treatment, expected in Q2 of this year.