Zwickau/Freiburg (dpa) – When little Käthe gets on her balance bike and speeds off, her parents’ worried looks are fixed on her. Because even the smallest fall can have serious consequences for the girl from Zwickau in western Saxony. “Käthe should be treated like a raw egg,” explains her mother Katharina Hofmann.

The four-year-old suffers from the incurable butterfly disease. What sounds almost poetic means that those affected suffer frequent pain, extensive care and many restrictions in their everyday lives. Some only have a short life ahead of them.

Errors in the genetic material

Doctors speak of epidermolysis bullosa (EB) – a rare disease that is caused by changes in the genes. Some people carry a mutation but do not become ill. However, they can pass it on to their children. Like Katharina Hofmann and her husband Frank.

The defect in the genetic material leads to a weakening of the cohesion of the skin layers. The result: even the smallest injuries, friction or pressure lead to blisters and open wounds. Mucous membranes can also be affected, making eating difficult and causing painful internal injuries.

Katharina and Frank Hofmann still want to offer their Käthe as normal a life as possible. Despite all their worries, this includes the balance bike. But there are always moments of shock. Like last summer. “I walked with her, holding her hand,” remembers mother Katharina. Käthe stumbled. “I intuitively tried to hold her.”

What would have prevented or mitigated the fall for any other child caused Käthe even more damage. “When I held her, I pulled the top layer of skin off her hand like a glove. It was like a nightmare for me.” Käthe had to go to the hospital quickly, partly because her fingers were threatening to grow together.

Expert: around 2000 people affected in Germany

Cristina Has knows many such cases. She is one of the few experts for EB in Germany and looks after patients at the Epidermolysis bullosa Center at Freiburg University Hospital. “We conducted an epidemiological study and identified around 2,000 people affected in Germany,” reports Has.

They are often extremely limited in their everyday lives, and in the severe forms of EB they are severely disabled. The disease cannot currently be cured, and treatments can only alleviate the symptoms. Complications often arise. “These can include failure to thrive, anemia, difficulty swallowing and complications in the kidneys, heart and other organs,” says Has, “but also scarring of the hands and feet, so that the patients’ mobility is severely limited and they even end up in a wheelchair.”

Little Käthe also has to endure an extensive procedure every day in her young years. She is cared for by the child care service for eight hours a day. The carers accompany her to kindergarten in the morning. At lunchtime, when her peers are taking a nap to gather new energy for playing and romping, she has to undergo a complex change of special bandages. This also involves treating newly formed wounds. The whole process takes about two hours. Käthe herself is already visibly exhausted by this afternoon, but she holds on bravely. Only then can she sleep.

Those affected hope for gene therapy

For several years now, advances in the field of gene therapy have given hope to those affected and their families. In 2015, for example, a German-Italian research team took skin from a boy, genetically processed it and then transplanted it back onto the wound area. Around 80 percent of the skin was replaced in this way.

However, the procedure is very complicated and demanding, explains Has. To her knowledge, it has only been used on very few patients so far. The Catholic Hospital in Bochum, which was involved in the aftercare, says the boy is doing well and his skin is stable. However, no other treatments of this kind have been carried out there to date, according to a spokesperson.

There are also hopes for a new therapy from the USA. Vyjuvek is the name of the drug from the listed company Krystal Biotech, which was approved by the US FDA just over a year ago. It is based on a herpes virus that has been genetically modified in the laboratory. When applied to wounds as a gel, it delivers new collagen7A1 genes, which in turn form the collagen proteins that are missing in the skin. The result: the skin layers hold together better and wound healing is promoted. The company also applied for marketing approval for Europe in the autumn.

First patients in Germany receive new drug

The gel is already being used on two patients in Freiburg. “As far as I know, we are the first in Germany to use it, and even in Europe,” says Has. “What we see is that the wounds heal much faster than without this treatment.” Even complicated chronic wounds have healed. “We are positively impressed by the effect of the medication.”

She is increasingly receiving inquiries from patients specifically about this treatment. So far, however, this has only been possible within the framework of individual therapy trials. She does not expect general approval in Europe until the end of the year.

Therapy with problems

But this therapy also has its drawbacks. Firstly, it is extremely expensive. The costs are currently estimated at around 800,000 US dollars (around 737,000 euros) for a treatment over a period of six months – for just one patient. The gel has to be applied weekly by medical staff, explained Has.

In order to establish the therapy in the future, nursing services and wound centers close to the patient’s home would have to be integrated. “The treatment of the open wounds actually has to be lifelong,” the expert points out. However, it is to be expected that over time the patient’s wound surface will become smaller and the need for the medication will decrease.

From their point of view, there is hope that many patients will be able to improve their quality of life in the future with the help of therapy. Although the disease will not be cured, it could make everyday life easier for those affected, such as attending school, studying, training or pursuing a job.

The Hofmanns also have high expectations of the new medication for their Käthe. “I have read patient reports from the USA, and they are very promising,” says Katharina Hofmann. “I really hope that the children here who already have large chronic wounds will be able to benefit from this therapy – and my Käthe too, of course.”

Fundraising marathon in a Trabi through the USA

In order to raise awareness of those affected by the rare butterfly disease and to collect donations for treatment, the Hofmanns and a friend are relying on a classic from the GDR era: the cult car Trabant 601. It first rolled off the production line in Zwickau 60 years ago.

At the end of June, Jan-Erik Nord from Berlin plans to set off on a fundraising marathon through the USA in a champagne beige Trabi. He has about 6,000 kilometers ahead of him, from the east coast to Stanford in California. Nord wants to collect donations. His faithful companion will be a teddy bear, which Käthe gave him for the journey.

© dpa-infocom, dpa:240607-99-307647/2