In FOP patients, muscles and tendons gradually ossify. This very rare genetic defect is currently untreatable and has a poor prognosis. Two researchers have developed a new therapeutic approach that could inhibit bone growth. For their work, they have been granted the 2020 Eva Luise Köhler Research Award for Rare Diseases.
It can happen from one moment to the next: Tendons and muscles turn into bone. For people with the very rare disease fibrodysplasia ossificans progressiva (FOP), this is a daily threat. Sooner or later, they become increasingly stiff and immobile. How can these bone growth spurts be stopped? Professor Dr Martina Rauner and PD Dr Ulrike Baschant from the Medical Faculty of the Technical University of Dresden have found a possible answer.
The Disease
Fibrodysplasia ossificans progressiva (FOP) is a very serious genetic disorder that affects only about 800 people worldwide. The first typical sign is a deformity of the big toes, which is present at birth. However, FOP is often not detected and diagnosed until adolescence. The muscles and tendons of affected people gradually ossify. This can happen after an infection or injury – or sometimes for no apparent reason. The newly formed bone fragments cause pain and restricted movement. Most people with FOP are bedridden by the age of 30 and die by the age of 40, often from respiratory problems. There is currently no treatment that can save people from suffering or cure them. Prevention is therefore the current focus. This means giving patients the best possible protection against falls, injuries and infections.
The Research
Professor Dr Martina Rauner and PD Dr Ulrike Baschant from the Medical Faculty of TU Dresden have researched and developed a new therapeutic approach that could be used to specifically inhibit progressive ossification. The focus is on a protein molecule called transferrin receptor-2 (Tfr2), which is responsible for iron metabolism in the body. Thanks to the research of the two scientists, it turns out that it can do even more, namely stop excessive bone growth. This effect has already been demonstrated in mouse models. Based on this finding, a new drug could be developed in the future that – administered as a tablet or injected as a solution – would prevent relapses of the disease in patients.
The Future
In order for patients to be able to benefit from the new treatment concept in the future, the next step would be to put it through its paces in a clinical trial. After all, a drug is only approved if its efficacy and safety can be proven. Initial attempts have already been made to conduct such a trial in collaboration with a company. However, the project has not yet been realised. Professor Dr Martina Rauner: ‘We would be delighted to find a new collaboration to take forward this important research for FOP patients.
