UCB has scored an FDA approval for ultra-rare disease treatment Kygevvi, continuing the positive momentum for the Belgian company.
The U.S. nod for Kygevvi—which is the third rare disease drug approval for the company in less than three years—is to treat the genetic mitochondrial disease thymidine kinase 2 deficiency (TK2d). It is the first targeted medicine for the muscle-weakening disorder. Kygevvi is cleared for adults and pediatric patients who have experienced symptom onset by age 12.
When TK2d appears early in life, it increases the risk of rapid progression and death. It can be fatal within three years of symptoms emerging. TK2d strikes an estimated 1.64 in every 1 million people, affecting patients' ability to walk, eat and breathe independently.
Kygevvi is an oral solution comprised of the pyrimidine nucleosides doxecitine and doxribtimine, which integrate into skeletal muscle mitochondrial DNA. This approach has been shown to restore the mitochondrial DNA copy number in TK2d mutant mice, UCB explained.
“The approval of doxecitine and doxribtimine represents a pivotal moment for the TK2d community, who previously had no FDA-approved treatment options for this rare genetic mitochondrial disease beyond supportive [palliative] care,” Donatello Crocetta, the chief medical officer of UCB, said in a release.
The company expects to launch Kygevvi in the first quarter of next year. The treatment is also under review by European regulators.
The approval is backed by results from a phase 2 trial that showed Kygevvi reduced the risk of death by 86% when patients' outcomes were measured against an external control group of untreated patients. Participants in the two groups were matched up by age at symptom onset.
“We have been waiting for an approved treatment for many years, and this approval marks a significant milestone in how we can support and manage this debilitating condition,” Michio Hirano, M.D., a professor of neurology at Columbia University’s Irving Medical Center, said in a statement.
UCB has been on an upswing behind Bimzelx, which was approved for plaque psoriasis in 2023 and generated sales of 799 million euros ($918 million) in the first half of this year. Also contributing to the success have been myasthenia gravis drugs Rystiggo and Zilbrysq, both also approved in 2023, which produced combined sales of 239 million euros ($274 million) in the first half.
All told, UCB had a 25% increase in revenue in the first half of this year and followed in the third quarter with the highest market cap rise among top-20 companies in the industry at 41%.