Statistical analysis
As an exploratory study, no formal sample size calculations were performed. The safety population included all enrolled patients who received ≥ 1 dose of any study medication. The per-protocol set was defined as all enrolled patients who had no protocol violations and who had met one of the following criteria: (1) completion of ≥ 2 cycles of study medication with evaluable blood samples for FACS or ADCC at baseline and ≥ 1 postbaseline time point; (2) completion of one cycle of study medication with evaluable pretreatment (Day 1 Cycle 1) blood samples and complete evaluable blood samples at Cycle 1 for FACS (Days 3 and 8) and ADCC (Day 8). The clinical efficacy population included all enrolled patients who received ≥ 1 dose of any study medication and who also had at least one postbaseline CT scan.Continuous variables were summarized by frequency, mean ± standard deviation, median, interquartile range, and minimum and maximum values. Categorical variables were summarized by number and percentage of patients in each category. Arm-wise comparison of immune cell phenotyping was only carried out when values of at least three patients were available for each arm and the coefficient of variation for the respective cell type was lower than 25%. This resulted in Arms 2 and 3 being combined for some analyses.In order to normalize temporal change rates, frequencies of immune cells were calculated as a ratio of the posttreatment to pretreatment percentage of a defined cell subpopulation per patient. The median change factor, with the upper (Q1) and lower quartile (Q3), were calculated for each treatment arm. In addition to the relative change rates to baseline, the actual frequency differences (Δ%) were calculated to verify if high relative change rates are reflected by a significant change. The analysis of actual frequency differences is only mentioned in the results section if analysis of relative change rates to baseline would otherwise convey a misleading impression, e.g., if obtained data was close to the detection limit of the assay. To improve interpretation in ambiguous cases, total cell numbers were determined by back calculation in a non-validated analysis to confirm that relative and absolute changes in cell frequency are reflected in the respective subpopulation. Total lymphocyte and living cell numbers of patients were obtained for posttreatment Days 22, 43, 64, and 85 from the complete blood count. These non-validated analyses are only presented if they were helpful for the interpretation of cell frequency change.