Bone marrow aspirate showing multiple myeloma.
Elotuzumab, a novel targeted therapy that induces cell breakdown and death in certain cancerous cells, demonstrated notable response rates as combination therapy in a phase II study of patients with relapsed or refractory multiple myeloma.
The humanized monoclonal antibody, developed by Bristol-Myers Squibb, targets the cell surface glycoprotein CS1, which is expressed in the tumor cells of more than 95% of patients with multiple myeloma but is minimally expressed in normal cells.
In the ongoing trial, 73 patients previously treated with 1 to 3 prior therapies were enrolled. Patients received lenalidomide and low-dose dexamethasone with either elotuzumab 10 mg/kg or elotuzumab 20 mg/kg.
Of the 36 patients in the elotuzumab 10 mg/kg group, 33 (92%) achieved an objective response rate (ORR), while a 100% ORR was achieved in patients who had received 1 prior therapy before treatment. Of the 37 patients in the elotuzumab 20 mg/kg arm, 27 (73%) achieved an ORR, and an ORR of 82% was seen in patients who received only 1 prior therapy.
After a 14.1-month median follow-up, between 65% and 75% of patients treated with elotuzumab 10 mg/kg combination therapy achieved progression-free survival (PFS). The most common grade 3/4 treatment-emergent adverse events were neutropenia (16%), thrombocytopenia (16%),and lymphopenia (16%).
Two phase III trials incorporating elotuzumab are currently underway. The ELOQUENT 1 study is assessing PFS in previously untreated patients who received elotuzumab 10 mg/kg plus lenalidomide and low-dose dexamethasone, while the ELOQUENT 2 study is assessing PFS in patients with relapsed or refractory multiple myeloma receiving the same dosage.
Lonial S, Jakubowiak AJ, Jagannath S, et al. A phase 2 study of elotuzumab in combination with lenalidomide and low-dose dexamethasone in patients with relapsed/refractory multiple myeloma. Blood. ASH Annual Meeting. 2011;118(21): abstr 303.