A pooled analysis of 3 combination drug regimens used to treat refractory/relapsed multiple myeloma reaffirms their safety, experts say, but does little to distinguish which approach works best.1
The study, done at the department of hematology at Weifang People’s Hospital in the Shandong Province of China, evaluated the overall response rates of 2220 patients treated with carfilzomib, panobinostat or elotuzumab combination therapies, once initial treatments failed.
Response rates ranged from a high of 71% in 449 patients on elotuzumab-containing combinations to roughly half of 597 patients treated with panobinostat-containing combinations. In the largest group of patients—1211—the overall response rate was 61% with carfilzomib after relapse.
“This study provides a hint of safety and efficacy in these early trials,” said Elad Sharon, MD, a senior investigator in the National Cancer Institute’s cancer therapy evaluation program in Bethesda, Maryland. “But we need more data from randomized clinical trials, as they give us a more robust understanding “of which anti-myeloma drugs carry the greatest benefit for patients.”
Only 2 of the 20 prospective studies evaluated through February 2016 included data from randomized clinical trials, a shortcoming cited by the authors of the present study, as well as by Dr Sharon. Three of the studies provided only interim results.
In the absence of a gold standard for treating these incurable blood cancers, all 3 drug regimens play important roles in the relapsed setting, according to clinicians, so pulling together data in 1 place may be helpful for future analyses. Each of the drug regimens attack cancer in different ways.
Carfilzomib (Kyprolis) for example, works by preventing the breakdown of certain cellular proteins needed to keep cell division under control, while panobinostat (Farydak) interacts with proteins inside the cell to slow over-development of plasma cells, the hallmark of this disease. Elotuzumab (Empliciti), 1 of several monoclonal antibodies now available, targets proteins found on the surface of myeloma cells that are thought to heighten their visibility to immune system attack.2
RELATED: Prognostic Index Predicts Survival, Time-to-first-treatment in CLL
“Right now, no 1 approach is best,” said Neha Korde, MD, a multiple myeloma specialist at Memorial Sloan Kettering Cancer Center in New York, New York. “Which drugs clinicians use depends on the type of relapse you’re seeing.”