Alemtuzumab is currently approved as a first-line treatment
against B-cell chronic lymphocytic leukaemia. Treatment
with the antibody results in the depletion of CD52+
tumour cells but the mechanism(s) involved are not welldefined.
In vitro studies indicate that alemtuzumab is
capable of complement-dependent cytotoxicity and antibody-
dependent cell-mediated cytotoxicity (ADCC), as
well as induction of apoptosis,12–17 but the extent of the
role played by these various mechanisms in vivo remains
to be established