Combination therapy with monoclonal antibodies for treatment of newly diagnosed multiple myeloma.

Monoclonal antibodies (mAbs) with new mechanisms of action are emerging as promising agents for patients with multiple myeloma (MM). Of these, anti-CD38 antibodies and anti-signaling lymphocytic activation molecule F7 (SLAMF7) antibody have demonstrated efficacy for relapsed and refractory myeloma (RRMM). Two CD38-targeting antibodies, daratumumab and isatuximab had significant activity as single agents, whereas the SLAMF7-targeting antibody, elotuzumab, did not. Patients with RRMM treated with 16 mg/kg daratumumab achieved at least PR of 36% and 29% in two distinct phase 2 studies. More favorable results of phase 3 study of 16 mg/kg daratumumab with lenalidomide and dexamethasone revealed that 92.9% of patients with RRMM achieved at least partial response (PR), with a 43.1% complete response (CR) rate. The median PFS was better in daratumumab arm (Not Reached) than control arm (18.4 months). When combined with lenalidomide plus dexamethasone, elotuzumab, at a dose of 10 mg/kg, improved the median PFS from 14.9 months to 19.4 months in a phase 3 study named ELOQUENT-2. In addition to IMiDs, bortezomib was a hopeful partner. Regarding toxicity, these mAbs are tolerable even in elderly patients. The most common adverse event is an infusion-related reaction. Based on several published reports, we suggest that mAbs combined with standard agents could be successfully adapted for the treatment of newly diagnosed patients with MM.