Kiadis Pharma N.V. announced that new data supporting the Company’s NK cell therapy is being presented at the 46th Annual Meeting of the European Society for Blood and Marrow Transplantation (EBMT). The poster presents data from 13 patients treated with relapsed/refractory acute myeloid leukemia (R/R AML) who received treatment with FC21 expanded NK-cells during a Phase I study conducted by Lucia Mariano da Rocha Silla, MD, PhD, at Hospital de Clínicas de Porto Alegre (HCPA) in Brazil. In this study, sponsored by the Brazilian Agencies for Research development, the adoptive transfer of haploidentical expanded NK cells to restore NK cell numbers and anti-leukemia function in patients with relapsed/refractory AML was investigated. Patients with relapsed, refractory, or CNS-positive AML respond poorly to chemotherapy. Naturally occurring NK cells have anti-leukemic activity but are deficient in numbers and function in AML patients and are ablated by high dose chemotherapy. The adoptive transfer of haploidentical expanded cells to restore NK cell number and anti-leukemic function in patients with relapsed/refractory AML was studied. In this Phase I study, haploidentical donors were selected after HLA and KIR typing. NK cells were expanded on feeder cells and cryopreserved for infusion at the assigned dose level, then thawed and infused three times per week over 2 weeks, for a total of six doses, following fludarabine, cytarabine, and G-CSF (FLAG) treatment. Patients were treated in 3 dose cohorts of 106, 5x106, and 107 NK cells/kg/infusion. Response was assessed at day 30. In this study, 13 patients, ages 2 – 61 years, with primary refractory (n=5) or relapsed (n=8) AML were treated (one patient was treated twice). Patients had a median of five prior therapies, and nine had undergone prior stem cell transplantation. Four patients had disease in the central nervous system (CNS), including one patient with bone and nerve root disease and one with probable mycetoma. The FC21-NK-cell therapy was well tolerated with manageable toxicity. Complete response and overall response rates were 50% and 78.6%, respectively, including unexpected CNS responses that were associated with localized inflammation. Median overall survival and disease-free survival after treatment were 231 and 186 days, respectively. The data show that repeated infusions of cryopreserved FC21-NK cells are well-tolerated and demonstrate encouraging.