Disclosed is a composition comprising an antibody specific for CD38 comprising an HCDR1 region of sequence SYYMN (SEQ ID NO: 14), an HCDR2 region of sequence GISGDPSNTYYADSVKG (SEQ ID NO: 2), an HCDR3 of sequence DLPLVYTGFAY (SEQ ID NO: 3), an LCDR1 region of sequence SGDNLRHYYVY (SEQ ID NO: 4), an LCDR2 region of sequence GDSKRPS (SEQ ID NO: 5), and an LCDR3 region of sequence QTYTGGASL (SEQ ID NO: 6); and either (a) thalidomide, a thalidomide analogue, lenalidomide, or pomalidomide, or (b) bortezomib, for use in the treatment of multiple myeloma and/or non-hodgkins lymphoma.