Consistent Benefit Over Time in Elotuzumab Studies
The immunostimulatory monoclonal antibody elotuzumab (Empliciti), which was approved by the FDA in December 2015, is being studied in combination with immunomodulatory drugs and proteasome inhibitors in patients with relapsed or refractory multiple myeloma. Results presented at ASH 2015 show continued benefit from these regimens.
Similarly, an update of a study evaluating elotuzumab plus bortezomib (Velcade) and dexamethasone showed a 24% reduction in the risk for progression or death, and a 25% reduction in the risk for death.
Elotuzumab is approved in combination with lenalidomide and dexamethasone in previously treated patients with relapsed or refractory disease.
The ELOQUENT-2 study involved 646 patients with relapsed or refractory multiple myeloma who were randomized to elotuzumab plus lenalidomide and dexamethasone, or to lenalidomide and dexamethasone alone. As of the most recent August 2015 data cutoff, the patients in the elotuzumab arm had a 27% reduction in progression or death risk compared with lenalidomide and dexamethasone alone (hazard ratio [HR], 0.73; P = .001) at 3 years.
The median progression-free survival (PFS) was 19.4 months in the elotuzumab arm and 14.9 months in the control arm, and the PFS rates were 26% versus 18%, respectively.
“The progression-free survival benefit with elotuzumab plus lenalidomide/dexamethasone was maintained over time,” said Paul G. Richardson, MD, Director of Clinical Research, Jerome Lipper Multiple Myeloma Center, Dana-Farber Cancer Institute, Boston. With the triplet, 38% fewer patients needed a subsequent line of treatment. The PFS benefit was observed across all the subgroups.
The interim overall survival (OS) analysis demonstrated a strong trend in favor of the combination (HR, 0.77). The median OS was 43.7 months with elotuzumab plus lenalidomide and dexamethasone and 39.6 months with lenalidomide plus dexamethasone.
“Updated safety and tolerability data are consistent with previous findings, confirming that there is minimal incremental toxicity associated with the addition of elotuzumab to lenalidomide,” Dr Richardson said.
Elotuzumab may also be paired with a proteasome inhibitor, according to the updated results from a study of the drug plus bortezomib and dexamethasone that were presented by Antonio Palumbo, MD, Associate Professor, University of Torino, Italy.
The study included 152 patients with relapsed or refractory multiple myeloma who had received at least 1 previous line of treatment. The patients were randomized to elotuzumab plus bortezomib and low-dose dexamethasone, or to bortezomib plus dexamethasone.
“The longer term follow-up demonstrates prolonged progression-free survival with elotuzumab plus bortezomib, and a safety profile that is consistent over time, with minimal incremental toxicity, compared with bortezomib alone,” Dr Palumbo said. “At the 2-year follow-up, elotuzumab in combination with bortezomib continues to show durable efficacy versus bortezomib alone.”
At 2 years, the PFS rates were 18% in the elotuzumab arm and 11% in the control arm. The median PFS was 9.7 months versus 6.9 months, respectively (HR, 0.76; P = .018), and the 2-year OS was 73% and 68%, respectively.
The median OS was not reached with elotuzumab, but was 34.7 months in the control arm. “In the overall survival analysis, the trend is in favor of elotuzumab in combination with bortezomib,” Dr Palumbo said.