#$%^&*AU2020220048A120200903.pdf#####ABSTRACT A targeted T-cell engaging agent for treating a condition characterized by the presence of unwanted cells includes (a) a targeting moiety that is capable of targeting the unwanted cells； (b) a first T-cell engaging domain capable of T-cell engaging activity when binding a second T-cell engaging domain, wherein the second T-cell engaging domain is not part of the agent； (c) at least one inert binding partner capable of binding to the first T-cell engaging domain such that the first T-cell engaging domain does not bind to the second T-cell engaging domain unless the inert binding partner is removed； and (d) at least one cleavage site separating the first Tcell engaging domain and the inert binding partner, wherein the cleavage site is: (i) cleaved by an enzyme expressed by the unwanted cells； (ii) cleaved through a pH sensitive cleavage reaction inside the unwanted cell； (iii) cleaved by a complement dependent cleavage reaction. See Fig. 1.
