European Commission approves KYGEVVI® for TK2d
IMP warmly welcomes the decision by the European Commission to approve KYGEVVI® (doxecitine and doxribtimine) as the first and only treatment for people living with thymidine kinase 2 deficiency (TK2d) in the European Union.
This landmark approval represents a major breakthrough for individuals and families affected by TK2d—an ultra-rare, life-threatening mitochondrial disease characterised by progressive muscle weakness and a severe impact on daily life. Until now, patients in Europe have had no approved treatment options beyond supportive care.
The European Commission’s decision follows a positive opinion from the European Medicines Agency and is based on clinical data showing improvements in motor function and reduced reliance on ventilatory and feeding support among treated patients.
Importantly, this approval builds on momentum seen globally, following approval of KYGEVVI® by the U.S. Food and Drug Administration (FDA) in 2025, marking another significant step forward for the international mitochondrial disease community.
A significant moment for patients across Europe
IMP recognises this approval as a pivotal moment for the mitochondrial disease community. For the first time, patients across Europe living with TK2d may gain access to a therapy that addresses the underlying biology of the disease, offering new hope where previously there was none.
“This is truly transformative news for patients and families affected by TK2d across Europe. After years of unmet need, the availability of an approved treatment offers hope, improved outcomes, and a tangible step forward in care,” said Paula Morandi, Chair of International Mito Patients.
The importance of the patient voice
IMP is proud to have represented the international mitochondrial disease patient community throughout the regulatory process, ensuring that the lived experience of patients and families was reflected in discussions and decision-making.
“At IMP, we are committed to ensuring that the patient voice is heard in the development and approval of new therapies. We are proud to have contributed to this process and to have advocated for timely access to treatment for the global mito community,” said Jo de Bry, Director of Development & Operations at IMP.
Looking beyond Europe
While this approval is a major milestone, IMP emphasises the importance of equitable global access. The organisation calls on regulatory authorities worldwide to follow the European Commission’s decision and accelerate access to KYGEVVI for patients in other regions.
“We hope that regulators around the world will build on this momentum and work swiftly to make this treatment available to all patients who may benefit from it,” added Morandi.
Continuing the journey
IMP also acknowledges and thanks all patients, families, researchers, clinicians, regulators and partners—specifically UCB—for their dedication in bringing this therapy to approval. This achievement demonstrates what is possible through collaboration and sustained advocacy.
IMP will continue to work with its global network to support access, raise awareness, and advocate for further treatment developments for mitochondrial diseases.