Acute lymphocytic leukaemia (ALL) is a malignant blood disease and the most common type of cancer in children. In Finland approximately 50 children get the disease every year.
According to Kim Vettenranta, professor of cell therapy and blood transfusion medicine at the University of Helsinki, the prognosis for ALL is these days relatively good.
“With currently available therapies, approximately 98% of children with the disease are alive and disease-free five years after diagnosis.”
The treatment and treatment outcomes of ALL have taken enormous strides in the last 40 or 50 years. The first bone marrow stem cell transplantations for child patients were carried out in the late 1960s in the United States. In Finland, the treatment method was introduced in 1974 by Professor Emeritus Martti Siimes who worked as a physician at the Children’s Hospital.
“The basic idea of bone marrow transplantation used in treating leukaemia has remained unchanged to this day: healthy stem cells are extracted from a healthy donor and transplanted into a leukaemia patient after conditioning.”
According to Vettenranta, the research on and development of stem cell therapies for leukaemia have been particularly intense in the last decades. Vettenranta and his research group have contributed to elevating children's stem cell transplants for leukaemia to their current level.
“Together with my group, I have taken part in developing stem cell therapies specifically for child patients. Among other things, we have investigated the regulation of immune system recovery, its monitoring after bone marrow transplantation and the treatment of graft-versus-host reaction.”
Vettenranta’s professorship is funded by donations: the University decided to establish the position with a donation made by the Finnish Red Cross Blood Service for the field of education in medical sciences and pharmacy. Cooperation between his research group (University of Helsinki/Helsinki University Hospital/Finnish Red Cross Blood Service) and the New Children’s Hospital of the Hospital District of Helsinki and Uusimaa is close, as the Blood Service is responsible for identifying stem cell transplant donors and related logistics.
T cells are the key
Targeted cell therapy is among the latest forms of treatment for leukaemia, entailing the utilisation of T cells from the patient’s own immune system. In this therapy, T cells are extracted from the patient, after which they are modified by employing gene technology to identify malignant leukaemia cells.
As such, the principle of targeted cell therapy has been known for approximately 30 years. However, what remained a problem for a long time was the inability to fully activate T cells that attack malignancies, as the signal emitted by cancerous cells themselves was too weak.
“T cells, inherent to the human body, are extremely adept at killing cancerous cells if they can be tuned to the correct frequency,” Vettenranta sums up.
At the New Children’s Hospital, the first child patient suffering from leukaemia has already been treated with this targeted cell therapy.
Vettenranta draws plenty of motivation from the evolution of treatment forms as well as from helping patients.
“For the next five years, I aim to introduce what is known as version 2.0 of cancer cell therapy in Finland, much like Martti Siimes in his time brought us version 1.0 in the 1970s, only at that time in terms of bone marrow transplants. That would hopefully enable us to treat also the most difficult cases, the remaining 2–3% of patients, in the foreseeable future.”