Standard therapies of leukemia include remission chemotherapy and hematopoietic stem cell transplantation. More recently, immunotherapies with checkpoint inhibitors and chimeric antigen receptor (CAR)-modified cytotoxic T lymphocytes have evoked striking successes. Despite these important improvements, significant fractions of leukemia patients are either unresponsive or will relapse from these treatments. Therapy options for most solid cancer types are even less promising.
Natural killer (NK) cell-based therapies are emerging as novel attractive therapeutic approaches to improve the efficacy of cancer treatment and to overcome resistance to current therapies of leukemia and solid cancers. NK cells are a type of lymphocytes and form an important part of the innate immune system with the ability to kill harmful cells. Whereas T lymphocytes can have toxic side effects, NK cell usually are well tolerated.
The main objective of the MATURE-NK project was to further develop and improve technology and reagents for NK cell-based immunotherapies. This included improving selection of tumor-reactive NK cell subtypes and developing technology for enhancing their anti-tumor cytotoxicity as well as manufacturing of therapeutic NK cells for clinical NK cell infusions.
The project was designed to combine expert laboratories in basic, clinical and company-related research and development in the NK cell field. Thirteen early stage researchers performed the research work as part of their PhD theses and were trained to become experts for the growing area of cellular immunotherapies.
In conclusion, the project has achieved significant progress in NK subtype selection, modification and manufacturing of therapeutic NK cells that will impact on the further development of NK cell-mediated cancer therapies. This includes improvements in selection of NK cell donors, tumor-reactive NK subsets and amplification of NK reactivity by CAR-modification, checkpoint inhibitors and NK cell engagers. Exemplary therapies were successfully tested in animal cancer models, GMP-compliant manufacturing of CAR-modified NK cells was improved and an exemplary protocol for a clinical leukemia trial drafted. The results have been described in numerous scientific manuscripts and in a priority application filed in 2022 by an industrial partner.