NIJMEGEN, the Netherlands – 1 June 2022: Khondrion (or the “Company”), a clinical stage biopharmaceutical company discovering and developing therapies targeting primary mitochondrial diseases, today announces the appointment of Tom Pulles, MD, as Chief Medical Officer (CMO).

Dr. Pulles joins the leadership team to oversee the clinical development of Khondrion’s wholly-owned lead asset, sonlicromanol, a potentially first-in-class oral small molecule in development to treat a range of mitochondrial diseases in children and adults. Topline data from the ongoing KHENERGYZE Phase IIb clinical study evaluating sonlicromanol in adult patients with MELAS spectrum disorders is expected in the third quarter of 2022. Dr. Pulles will also oversee the broader clinical strategy and medical operations of the Company, including the ongoing KHENEREXT open label extension study of adult patients who have completed the Phase IIb study, and the KHENERGYC paediatric Phase II study in children with genetically confirmed primary mitochondrial disease.

Prof. Dr. Jan Smeitink, Chief Executive Officer at Khondrion, said: We are delighted to welcome Tom to the Khondrion team as our new Chief Medical Officer. Tom’s extensive experience in clinical development, medical affairs and patient engagement within the rare disease space will be extremely important as we progress towards the late stage development of our lead asset, sonlicromanol, and continue to develop our pipeline and expand our clinical capabilities.”

Dr. Pulles has more than 20 years’ experience in the pharmaceutical and biotechnology industries, primarily in global and regional medical affairs, clinical development, and patient engagement. He joins Khondrion from Ultragenyx Pharmaceutical Inc., a NASDAQ-listed, rare and ultra-rare genetic disease company, where he built the European medical organisation in roles of increasing seniority, most recently as Head of Medical Affairs, EMEA. During his time at the company, Dr. Pulles played a crucial role in global and regional clinical development, medical affairs and launch plans for potential new treatments. Prior to this, Dr. Pulles held a number of medical strategic, entrepreneurial and leadership positions at Solvay Pharmaceuticals, Sanofi Aventis, MEDCON International, and Shire Pharmaceuticals. He holds a Doctor of Medicine (MD) degree from Utrecht University in The Netherlands.

Dr. Tom Pulles, Chief Medical Officer at Khondrion, said: “Khondrion is at an important stage in its journey and I look forward to helping drive the Company’s purpose and mission of bringing clinically meaningful medicines to patients living with devastating mitochondrial diseases. I have spent my career working to help patients with rare and ultra-rare diseases and I am excited to work with Jan and the team to advance the sonlicromanol clinical programme, working with the medical and patient communities to leverage the transformational potential of sonlicromanol for people living with primary mitochondrial diseases.”


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Khondrion BV

Prof. Dr. Jan Smeitink, CEO


Tel: +31-24-7635000


Consilium Strategic Communications
Mary-Jane Elliott, David Daley, Melissa Gardiner
Tel: +44 20 3709 5700


About Khondrion

Khondrion is a clinical stage biopharmaceutical company developing therapies for patients with inherited mitochondrial diseases. Based on proprietary science and a deep biological understanding of mitochondrial dysfunction, the company is advancing its lead drug candidate sonlicromanol, a first-in-class, oral small molecule targeting key underlying mechanisms of mitochondrial disease based on the drug’s unique triple mode of action. Sonlicromanol is a reductive and oxidative distress modulator with anti-inflammatory properties.

One of the most advanced disease-modifying drug candidates for mitochondrial disease in development, sonlicromanol is currently being tested in a Phase IIb trial and a 12-month open-label extension study in adult patients with MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) spectrum disorders, as well as in a 6-month Phase II study in children with genetically confirmed primary mitochondrial diseases and who suffer from motor symptoms. The compound has been granted orphan drug designations for the treatment of MELAS, Leigh disease and patients with maternally inherited diabetes and deafness (MIDD) in Europe, and for all inherited mitochondrial respiratory chain disorders in the US. It has also been granted a Rare Pediatric Disease designation in the US for the treatment of MELAS. Sonlicromanol and other compounds from Khondrion’s proprietary library have the potential to be developed for a wide range of diseases and conditions with the aim of benefiting patients whose daily lives are severely impacted by mitochondrial impairment.


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About mitochondrial disease

Mitochondrial disease occurs when mitochondria, found within all cells of the human body and responsible for producing the energy necessary for cells to function, are defective. This can result in a wide range of serious and debilitating illnesses occuring shortly after birth or later in life. Signs and symptoms of these can include: cognitive problems, learning disabilities, blindness, deafness, heart failure, diabetes, fatigue, intolerance to exercise, muscle weakness and gait problems, and stunted growth. Orphan diseases of the oxidative phosphorylation system like Leigh disease, MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) spectrum disorders, MIDD (maternally inherited diabetes and deafness), LHON (Leber’s hereditary optic neuropathy) and other respiratory chain/ oxidative phosphorylation disorders, are all examples of mitochondrial disease.