Immunotherapy for Leukaemia Patients

Over the past few years, together with the US company Juno, scientists from the German Center for Infection Research (DZIF) have been developing an innovative cell purification method with which the desired memory T cells can very specifically be isolated from healthy donor blood. These special immune cells will now be administered to patients for the first time in a phase I/II study, after a bone marrow transplant. The cells are to protect the patients from infection until their own immune defence system starts to function again.

Cell-based immunotherapy therapies are produced in clean rooms under sterile conditions. Source: TUM/Michael Neuenhahn

After a bone marrow transplant, patients are usually at serious risk of infection. Their immune system, which has been suppressed together with the degenerate cells, needs time to regenerate which can take up to a year. At the German Center for Infection Research (DZIF) in Munich, leukaemia patients, after undergoing a bone marrow transplant, will be treated for the very first time with specially purified T memory cells, to avoid such infections. This innovative cell purification method was developed together with the US-based biopharma Juno Therapeutics. The researchers are confident that the method can be applied to other diseases.

Staving off infections

Within the clinical study, specially purified T memory cells are administered to leukaemia patients prophylactically in small quantities. The purified T cells can frequently detect and prevent the pathogens from occurring. “In this current trial, these specially purified memory T cells, subgroups of T lymphocytes, have been administered in this form for the first time in the world,” explains Dirk Busch, from the Technical University of Munich, who is heading the study with his colleague Michael Neuenhahn. The scientists were able to show in many preliminary tests that these cells offer protection against infections even when administered in the smallest, well-tolerated doses. A great advantage, because T cells can be a blessing and a curse. If they are administered to the patient unfiltered in too large a quantity, the patient’s immune system could reject them, by which the T cells can also attack healthy cells. However, if the T cells are not present at all, the dreaded infectious disease pathogens can multiply.

Avoiding rejection reactions

“Our aim is to decrease the risk of infection without risking rejection reactions,” explains Neuenhahn and, after all the preliminary testing, he is optimistic that this will work.

Over the course of one year, 30 leukaemia patients will receive this T cell prophylaxis. In each case, the dosage will be incremented gradually so as to identify the optimal dose. The patients will be examined for infections in closely meshed time intervals. The cell purification will take place in special clean room facilities in Munich. Trial patients will be treated in Würzburg as well as at the DZIF partner sites in Tübingen and Hannover.