The present invention discloses an isolated trifunctional
bispecific antibody for use in a method of treating a patient suffering from a
disease and / or a disorder associated with reactivation of Epstein-
Barr virus (EBV) in at least B cells and potentially also other susceptible cells such as susceptible epithelial cells, comprising: providing an
autologous cell preparation of enriched B cells of said patient; incubating said enriched B cells with the trifunctional
bispecific antibody for a time-period sufficient to establish a
physical interaction between said trifunctional bispecific antibodyand said enriched B cells to obtain an incubation mixture; transferring said incubation mixture obtained after incubation into the same patient, wherein said trifunctional
bispecific antibody comprises: (a) a first binding arm which binds to a
B cell via a
B cell surface
antigen; (b) a second binding arm which binds to a
T cell via a
T cell surface
antigen; (c) an Fc-portion which binds to an Fcreceptor-positive
cell. The present invention also discloses a pharmaceutical composition comprising the said isolated trifunctional bispecific
antibody for use in the treatment of a patient sufferingfrom a
disease and / or a disorder associated with reactivation of EBV in B cells, and an ex-vivo method for preparing the said pharmaceutical composition.