September 18 – 24 is World Mitochondrial Disease Week, during which a wide range of events are held across the world with the aim of raising awareness of mitochondrial disease. In connection with World Mitochondrial Disease Week, BioStock takes a closer look at the patient perspective in this, still relatively unknown, group of diseases.

Mitochondrial diseases are caused by malfunctioning energy production in the mitochondria. The mitochondria are responsible for the energy production in the body’s cells and thus play a key role in making sure that the human body functions the way it is supposed to. Malfunctioning mitochondria can lead to a wide range of severe symptoms and often lead to a shortened life span for the sufferer.

Long range of symptoms

For Australian Shelley the list of symptoms is long. It includes bilateral sensorineural hearing loss, daytime hypertension and a thickening of the left side of her heart which means she has a high risk of heart failure. She is also insulin dependent as she suffers from mitochondrial diabetes. In addition, she suffers from muscle weakness and exercise intolerance.

Specific types of mitochondrial disease are rare, but one in 200 people will carry a genetic defect that could lead to a mitochondrial disease. It is estimated that one in 5000 individuals could develop a serious illness. Research has established that many mitochondrial diseases are inherited, while others can occur spontaneously.  

With no cures, mito, the often used by sufferers to refer to their disease, can be a severely life limiting condition if the onset is in infancy or childhood. In the past, many adults have found themselves mis- and undiagnosed for years, suffering seemingly unrelated symptoms and it is often not until the patient has been looked at holistically that mitochondrial disease is considered. But now, with the emergence of specialist mito disease centres and the wider use of genetics, diagnosis is improving.  

Hereditary disease

For Shelley, the journey started with her mother experiencing a rapid decline in health, where she lost muscle in most parts of her body, leading to a struggle just to take a breath of air. After several doctors’ appointments and hospital admissions, it was clear that Shelley’s mother suffered from heart failure, muscle weakness and fluid in her lungs, and she passed away shortly after the symptoms progressed.

After Shelley’s mother had passed, it was established that she had suffered from a mitochondrial illness and there were indications that the same was true for Shelley’s brother. After genetical tests, Shelley found out that she too has a mitochondrial disease – more specifically MELAS (Mitochondrial enchephalopathy, Lactic Acidosis and Stroke-like episodes). Not long after that, her brother passed away at the age of 34, after having gone through a period of myoclonus seizures, migraines, vomiting, hallucinations, and stroke-like episodes where he lost his eyesight for weeks on end. With both her mother and brother having passed, Shelley fears for her own wellbeing and future and is afraid that she will pass on the disease to any future children.

Raising awareness to advance research

With no FDA-approved treatments for mitochondrial diseases, the outlook for sufferers of mitochondrial diseases is bleak. Raising awareness around mitochondrial diseases is essential in order to further the research and the clinical development in this uncommon group of diseases. This is why, every September, World Mitochondrial Disease Week is organised globally with the aim of drawing attention to the disease through various activities. The initiators behind World Mitochondrial Disease Week are International Mito Patients, a network bringing together 17 patient organisations from across the globe.

Two candidates in pipeline

But there are a number of pharmaceutical companies working to change that situation. One of them is Swedish Abliva that develops two candidates in the primary mitochondrial disease space. The lead candidate KL1333 is developed for the treatment of adult multisystemic mitochondrial disease. The candidate has Orphan Drug Designation in both Europe and the US, and is currently being prepared for a key phase II/III study to start later this year. The second candidate, NV354, is in preclinical development and is targeted towards the pediatric mitochondrial disease Leigh syndrome, as well as MELAS and LHON.

Read more about Abliva’s work here.