Telbivudine

Brussels (Belgium) 31 March 2026, 07:00 (CEST) – UCB (Euronext Brussels: UCB), a global biopharmaceutical company, today announced that the European Commission (EC) has granted marketing authorization under exceptional circumstances for KYGEVVI (doxecitine and doxribtimine) for the treatment of paediatric and adult patients with genetically confirmed thymidine kinase 2 deficiency (TK2d) with an age of symptom onset on or before 12 years.1 It is the first and only approved treatment for TK2d. “The European Commission’s approval of KYGEVVI marks a historic milestone for the TK2d community. For the first time, people across Europe living with this ultra-rare, life-threatening mitochondrial disease have access to an approved treatment beyond supportive care,” said Donatello Crocetta, Chief Medical Officer at UCB. “KYGEVVI is designed to support mitochondrial DNA maintenance in skeletal muscle, addressing a key biological driver of TK2d. We are deeply grateful to the patients, families, advocates, investigators, and clinical trial teams whose partnership, trust, and resilience made this achievement possible.” "TK2d has a profound impact on people living with the condition and their families and, until now, they have faced a heavy burden of unmet treatment need with incredible resilience,” said Caterina Garone, Associate Professor of Medical Genetics, University of Bologna, Italy. “The TK2d community has waited a long time for this moment which brings them new hope and marks an important step forward in how clinicians can manage this devastating disease.” Clinical efficacy Supporting data for EC approval came from pooled data from two studies* of treatment with KYGEVVI (doxecitine and doxribtimine) in patients with genetically confirmed TK2d with age of symptom onset ≤12 years. These studies investigated the impact of treatment on functional outcomes (i.e. motor milestones, ventilatory support, feeding support) as well as survival.1,4,9,10,11,12,13 In the studies, KYGEVVI was well tolerated with the most commonly reported adverse reactions of diarrhea (86%), vomiting (28%), abdominal pain (including abdominal pain upper) (26%).1 Developmental motor milestone ability: A decrease in the loss of motor milestones was observed following treatment initiation with KYGEVVI; 26/31 (84%) patients regained one or more motor milestones (e.g. sitting upright unassisted, holding head upright unassisted).1 Ventilatory support: Prior to treatment start, 18/39 (46%) participants initiated ventilatory support and no participants discontinued ventilatory support. After initiation of treatment, 5/21 (24%) participants started ventilatory support while 5/23 (22%) discontinued ventilatory support.1 Feeding support: Prior to treatment start, 12/39 (31%) participants had a feeding tube. After initiation of treatment, 4/28 (14%) participants started feeding support, with 2 of these participants subsequently discontinuing feeding support after initiation of treatment1 About TK2d TK2d is an ultra-rare, life-threatening, genetic mitochondrial disease characterized by progressive (worsening over time) and severe muscle weakness (myopathy).2,3,4,5 TK2d can impact all parts of a person's daily life and wellbeing and can become worse over time and impact the ability to walk, eat and breathe independently, often necessitating around-the-clock caregiver support.3,4,6 It is often fatal, with those experiencing initial symptoms on or before the age of 12 years facing a high risk of premature death (often occurring within 3 years after symptom onset).7 It is estimated that the worldwide prevalence of TK2d is 1.64 [0.5, 3.1] cases per 1,000,000 people.8 About KYGEVVI® The primary mechanism of action of KYGEVVI (doxecitine and doxribtimine) is the incorporation of pyrimidine nucleosides deoxycytidine (dC) and deoxythymidine (dT) into skeletal muscle mitochondrial deoxyribonucleic acid (DNA) to restore mitochondrial DNA copy number and improve skeletal muscle function in patients with TK2d. Doxecitine and doxribtimine likely utilize residual TK2 activity as well as cytosolic phosphorylation pathways such as thymidine kinase 1 and deoxycytidine kinase to increase mitochondrial DNA precursors deoxycytidine triphosphate and deoxythymidine triphosphate in the mitochondria.1 KYGEVVI was supported through EMA's PRIority MEdicines (PRIME) scheme, which provides early and enhanced scientific and regulatory support to medicines that have a potential to address patients' unmet medical needs. Marketing authorization under exceptional circumstances may be granted to medicines where the applicant is unable to provide comprehensive data on efficacy and safety under normal conditions of use, because the condition to be treated is rare or because collection of full information is not possible or is unethical.14 The EC approval follows the recent approval of KYGEVVI by the U.S. Food and Drug Administration (FDA) for the treatment of adults and pediatric patients living with thymidine kinase 2 deficiency (TK2d), with an age of symptom onset on or before 12 years.15 *These two studies comprise 39 participants with an age of TK2d symptom onset ≤12 years - the median age of TK2d symptom onset was 1.89 years (Q1, Q3 = 1.2, 2.7) and the median duration of treatment was 91.4 months (Q1, Q3 = 80.2, 117.8; all treated > 5 years). Survival was compared to an external control group, after matching on Age of Symptom Onset Category. Information on functional outcomes in the treated patients (motor milestones, ventilatory support, and feeding support) was collected during the pre- and post-treatment period and analyzed.1 For more information about the trials visit: https://clinicaltrials.gov/study/NCT03845712 (TK0102/NCT03845712) and https://clinicaltrials.gov/study/NCT03701568 (MT-1621-101/NCT03701568). KYGEVVI®▼ (doxecitine and doxribtimine) EU/EEA** Important Safety Information1 Increase in Liver Transaminases Elevated liver enzymes and liver dysfunction/failure have been observed as a clinical manifestation of TK2d. In clinical studies elevations in alanine aminotransferase [ALT] and/or aspartate aminotransferase [AST] have occurred in patients with TK2d following treatment with KYGEVVI. Transaminase levels should be checked prior to initiation of treatment, and changes in liver function monitored periodically during treatment with KYGEVVI and according to routine patient management. Gastrointestinal disturbances Gastrointestinal disturbances such as diarrhoea, vomiting, and abdominal pain (including abdominal pain upper) are very commonly reported adverse reactions with doxecitine and doxribtimine treatment. In the pooled safety population 37 out of 50 participants (74%) experienced diarrhoea early after treatment initiation (<3 months). The majority of events of diarrhoea were mild to moderate in severity and were generally self-limiting or improved with temporary dose reduction. Of 133 events of diarrhoea, 12% (16/133) required dose reduction with a median duration of 80 days (Q1, Q3=33.0, 201.5). None of the 50 participants discontinued due to gastrointestinal disturbances, including diarrhoea. Please consult the summary of product characteristics in relation to other side effects, full safety and prescribing information. European SmPC date of revision: [March] 2026 **EU/EEA means European Union/European Economic Area ▼ This medicinal product is subject to additional monitoring. This will allow quick identification of new safety information. Healthcare professionals are asked to report any suspected adverse reactions. For further information, contact UCB: Global Communications Nick Francis T: +44 7769 307745 nick.francis@ucb.com Corporate Communications, Media Relations Laurent Schots T +32.2.559.92.64 laurent.schots@ucb.com Investor Relations Antje Witte T +32.2.559.94.14 antje.witte@ucb.com Sahar Yazdian T +32.2.559.94.37 sahar.yazdian@ucb.com Yvonne Naughton T +44.175.344.7521 yvonne.naughton@ucb.com About UCB UCB, Brussels, Belgium (www.ucb.com) is a global biopharmaceutical company focused on the discovery and development of innovative medicines and solutions to transform the lives of people living with severe diseases of the immune system or of the central nervous system. With more than 9 000 people in approximately 40 countries, the company generated revenue of €7.7 billion in 2025. UCB is listed on Euronext Brussels (symbol: UCB). Follow us on X: @UCB_news Forward-looking statements This document contains forward-looking statements, including, without limitation, statements containing the words “potential”, “believes”, “anticipates”, “expects”, “intends”, “plans”, “seeks”, “estimates”, “may”, “will”, “continue” and similar expressions. These forward-looking statements are based on current plans, estimates and beliefs of management. All statements, other than statements of historical facts, are statements that could be deemed forward-looking statements, including estimates of revenues, operating margins, capital expenditures, cash, other financial information, expected legal, arbitration, political, regulatory or clinical results or practices and other such estimates and results. 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The EU's Committee for Medicinal Products for Human Use (CHMP) closed January with a slate of decisions Friday, including recommendations for Novo Nordisk and UCB drugs, while Sanofi's graft-versus-host disease (GvHD) treatment gets a second change and Eli Lilly settles for a label update.Novo Nordisk's KayshildOne of the more closely watched decisions was the conditional recommendation for Novo Nordisk's semaglutide to treat non-cirrhotic metabolic dysfunction-associated steatohepatitis (MASH) and liver fibrosis, a new indication for the GLP-1 agonist that the company plans to market as Kayshild. Semaglutide is already approved for diabetes as Ozempic and Rybelsus, and as Wegovy for weight loss.The opinion marks the first time a GLP-1 agonist has been cleared in Europe for MASH, and comes about five months after US regulators approved it under the Wegovy brand for the same indication based on data from the Phase III ESSENCE trial. Results there showed that 37% of patients achieved improved liver scarring without their steatohepatitis getting worse at 72 weeks, compared to 22.5% on placebo. Rates of steatohepatitis resolution without any increase in liver scarring were 62.9% and 34.1%, respectively.Sanofi's Rezurock re-examinedAfter having revisited its October negative opinion of Sanofi's Rezurock (belumosudil) for chronic GvHD, the EU drug advisory panel now recommends conditional approval in last-line patients ages 12 years and up. The ROCK2 inhibitor downregulates IL-17 and IL-21 and mediates signalling in immune cellular function and fibrotic pathways.Sanofi picked up the oral ROCK2 inhibitor via its $1.9-billion Kadmon buyout in 2021, just after the FDA had cleared it for GvHD. In the pivotal Phase II ROCKstar study, the drug plus standard of care delivered about a 73% response rate in patients who had received two to five prior lines of systemic therapy, with a median duration of 1.9 months.At the time, CHMP said ROCKstar's single-arm design made it hard to clearly determine Rezurock's benefit, while Sanofi said it wouldn't have confirmatory data until 2030. Still, the French drugmaker requested a re-examination of the negative October decision, and said Friday's CHMP recommendation was based on safety and efficacy data "from several clinical studies and real-world evidence," including ROCKstar."We…made the commitment to conduct a new post-approval confirmatory study, given the limited late-line treatment options available for EU patients," said Olivier Charmeil, Sanofi's EVP of general medicines.UCB's KygevviCHMP also issued a positive opinion under exceptional circumstances for Kygevvi, UCB's treatment for thymidine kinase 2 deficiency, a rare and often fatal mitochondrial myopathy. It is indicated for patients whose disease started at or before 12 years of age. Kygevvi, which was approved by the FDA last November, works by incorporating the pyrimidine nucleosides, deoxycytidine and deoxythymidine, into skeletal muscle cell mitochondria to help rebuild their DNA.The EU recommendation relied on a retrospective chart review and a single-arm Phase II study in 39 children, in which 84% regained one or more motor milestones after treatment with Kygevvi, suggesting improved motor function. The most common side effects were diarrhoea, vomiting and abdominal pain.A recommendation under exceptional circumstances means the authorisation can be granted with specific obligations that are reviewed each year.Incyte's Zynyz expandedIn oncology, CHMP backed an extension for Incyte's PD-1–blocking antibody Zynyz (retifanlimab) to treat adults with inoperable, metastatic or locally recurrent squamous cell carcinoma of the anal canal (SCAC) when combined with chemotherapy. The drug was initially authorised in Europe in 2024 for Merkel cell carcinoma.US regulators greenlit Zynyz for SCAC last year based on results from the Phase III POD1UM-303 trial. According to CHMP, half of SCAC patients treated with Zynyz plus chemotherapy lived for 9.3 months or longer without their cancer worsening, versus 7.4 months for placebo and chemotherapy.However, regulators acknowledged lingering uncertainty over overall survival benefit; half of patients treated with Zynyz lived for at least 32.8 months compared with 22.2 months for placebo, which was not statistically significant. Still, the committee pointed to improvements in progression-free survival as sufficient evidence of clinical value in a setting with few alternatives.Lilly's Mounjaro for heart failureMeanwhile, not all GLP-1 news ended with CHMP backing. The EU panel declined to grant a separate heart-failure indication for Lilly's dual GLP-1/GIP agonist Mounjaro (tirzepatide) in patients with obesity and preserved ejection fraction (HFpEF), instead opting to incorporate trial results into the product label.The drug is currently approved in Europe for treating type 2 diabetes and for chronic weight management in adults. "Although EMA did not recommend that a separate indication should be granted for the treatment of HFpEF, it agreed to include relevant data from the study submitted with the application in the medicine's product information," CHMP said, so that "healthcare professionals have access to up-to-date data on the effects of Mounjaro in adults with chronic HFpEF and obesity."Lilly withdrew a similar application last year in the US, where tirzepatide is sold as Zepbound for weight loss, after the FDA asked to see more clinical data. The filing was based on Phase III data from the SUMMIT study showing that Zepbound reduced the risk of heart failure complications by 38% versus placebo in patients with and without diabetes.