An ex vivo method for removal of tumor cells from intra-operatively salvaged blood

An ex vivo method for removal of tumor cells from intra-operatively salvaged blood comprising the following steps:

• (i) collecting an intra-operatively salvaged blood which may contain immune cells and tumor cells in a reservoir;
• (ii) contacting said intra-operatively salvaged blood from step (I) in the reservoir with at least one trifunctional antibody and/or with a scaffold protein, wherein said antibody or said scaffold protein comprises the following properties:
• a) binding to a T cell;
• b) binding to a tumor-associated antigen on a tumor cell;
• c) binding via its Fc-portion to an Fc-receptor positive cell, to obtain an intra-operatively salvaged blood containing cell aggregates, wherein said cell aggregates comprise said trifunctional bispecific antibody and/or said scaffold protein;
• (iii) separating an erythrocyte concentrate from the intra-operatively salvaged blood obtained from step (ii) via centrifugation;
• (iv) washing said erythrocyte concentrate from step (iii);
• (v) filtering the erythrocyte concentrate from step (iv) to remove residual of said aggregates and/or residual of said cell-bound trifunctional bispecific antibody and/or scaffold protein.