Cord Blood ‘Natural Killer’ Cells Benefit Acute Myeloid Leukaemia Patients

Acute myeloid lekaemia (AML) is a prevalent type of cancer in older adults. It is currently treated with intensive chemotherapy and forms of supportive care that lead to 40-60% of patients experiencing complete remission – eliminating signs of cancer. However, most patients relapse, resulting in a 5-year overall survival rate of about 10%.

For the first time, haematopoietic stem and progenitor cells (HSPCs) from partially HLA-matched umbilical cord blood have been used to generate natural killer (NK) cells These NK cells have been shown to temporarily restore immune system function in patients with Acute Myeloid Leukaemia and stave off relapse.

The HSPC-derived NK cells were transferred to ten older AML patients after they received lymphodepleting chemotherapy. In the next few days, the infused NK cells showed signs of successful maturation and establishment within the patients’ bodies. In the patient, the NK cells successfully increased levels of plasma factors and indicators of normal immune functions. Surprisingly, some patients with MRD (Minimal residual disease) in bone marrow before infusion became MRD negative for an extended period post-infusion. These results give hope for the use of cord blood stem cells in cancer therapy development.

The clinical trial was carried out by scientists at the American Association for Cancer Research and published in March 2017. The promising findings suggest that HSPC-NK cells could be used in future as an “off-the-shelf” form of immunotherapy for people living with AML.

Although the approach described above is a fantastic step forward into extending life in AML patients, it still needs further work regarding its ability to kill tumour cells.