UCB, a global biopharmaceutical company, has received U.S. Food and Drug Administration (FDA) approval for KYGEVVI, a treatment for adults and pediatric patients suffering from thymidine kinase 2 deficiency (TK2d), with symptom onset at or before 12 years of age. KYGEVVI is the first and only approved therapy for this devastating mitochondrial disorder.
TK2 deficiency is an ultra-rare, life-threatening genetic disease characterized by progressive muscle weakness (myopathy) and a high risk of premature death, often occurring within three years of symptom onset in children. Until now, patients had no treatment options beyond supportive or palliative care. The global prevalence of TK2d is estimated at around 1.64 cases per million people.
“The approval of doxecitine and doxribtimine represents a pivotal moment for the TK2d community who previously had no FDA-approved treatment options,” said Donatello Crocetta, Chief Medical Officer at UCB. “We extend heartfelt thanks to the patients, families, advocates, and clinical teams who made this achievement possible.”
Kristen Clifford, President and CEO of the United Mitochondrial Disease Foundation, described the FDA approval as “a breakthrough for an ultra-rare disease community in dire need of treatment options,” emphasizing that it “not only meets a critical medical need but also represents hope for the future.”
Dr. Michio Hirano, Professor of Neurology and Chief of the Division of Neuromuscular Medicine at Columbia University Irving Medical Center, highlighted the significance of the milestone, stating, “After decades of research, this approval marks a major step forward in how we can support and manage this debilitating condition.”
With KYGEVVI, UCB delivers a long-awaited therapeutic option for patients and families affected by TK2 deficiency, marking a transformative step in the treatment of rare mitochondrial diseases.