IMGN529 has exhibited potent antitumor activity in preclinical models of CD37+ NHLs.127,128 A phase 1 trial (NCT01534715) of IMGN529 in relapsed or refractory NHLs and CLL has recently been reported, showing manageable safety profiles and preliminary evidence of activity, particularly in DLBCL.129 AGS67E is a fully human monoclonal IgG2 antibody conjugated via a protease-cleavable linker to MMAE. Here, CD37 is linked to B-cell chronic lymphocytic leukemia.