Fig. 2

Statistics of NK cell cancer therapy with non-engineered and engineered NK cells used as monotherapy or in combination therapies. The pie charts present the major features of NK cell products reaching the clinical stage until December 2021, as reported on ClinicalTrials.gov. Data are presented for non-engineered NK cell products (based on N = 36 clinical trials, initiated after March 2017), engineered NK cell products (N = 53 trials), non-engineered (N = 62 trials) and engineered (N = 34 trials) NK cell combination therapies. For every pie, numbers indicate the percentage of the whole taken by each slice. A Cell sources used as starting material for the manufacturing of NK cell products, divided by category: peripheral blood-derived NK cells (PB-NK), umbilical cord blood-derived NK cells (UCB-NK), hematopoietic stem cells (HSCs), induced pluripotent stem cells (iPSCs) and NK cell lines (NK-92). Undisclosed sources are labeled as “Unspecified.” B Classification of the cancer indication targeted in clinical trials, divided between hematological malignancies and solid tumors. C and D Breakdown of the types of hematological malignancies (C) and solid tumors (D) indications most frequently targeted by NK cell therapeutics. Undisclosed indications are labeled as “Unspecified.” In B, C and D, one trial can include more than one indication. AML: acute myeloid leukemia; CML: chronic myeloid leukemia; MM: multiple myeloma; MDS: myelodysplastic syndromes; B-ALL: B cell acute lymphoblastic leukemia; CLL: chronic lymphocytic leukemia; NHL: non-Hodgkin lymphoma; HL: Hodgkin lymphoma