A stroke patient has been treated with a pioneering stem-cell therapy for the first time, in the only clinical trial of its kind.

The 49-year-old man is doing well after the operation in Germany, in which genetically engineered bone marrow stem cells were injected into his brain in the hope of assisting recovery.

The trial, led by Professor Thomas Brinker, of the International Neuroscience Institute in Hanover, is designed only to assess the safety of the new technique, and not to monitor its effectiveness. It will eventually involve 20 patients.

Even so, Professor Brinker said yesterday that the early indications looked good. “We see a path of recovery as good as this only in the minority of patients, so it is an encouraging start,” he said. “It is most important that we found [that there were] definitively no side-effects from the treatment.”

The therapy under trial is known as CellBeads, which uses mesenchymal stem cells – a type found in bone marrow that can form fat and muscle cells. These are genetically engineered to produce a protein that inhibits cell death, which could limit brain damage after a stroke.

The donated stem cells are encapsulated in special beads to protect them from the patient’s immune system, which would otherwise destroy them as foreign tissue. In this instance, the stem cells are used as a powerful means of delivering the protein – and not as replacement tissue.

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