MADRID – Patients with refractory/relapsed multiple myeloma had similar rates of progression-free survival (PFS) whether they were younger than age 65 or 65 years and older, based on the results of eight recent phase 3 trials in an analysis presented at the European Society for Medical Oncology Congress.
“The PFS benefit was significant in both younger and older patients with relapsed and refractory multiple myeloma with a cut off at 75 years,” reported Thierry Landre, PharmD, of the department of geriatric oncology, University of Paris 13, France. “Age, by itself, should not be a contraindication to the new myeloma drugs.”
In this meta-analysis, 5,421 patients were evaluated from the CASTOR and POLLUX trials, which evaluated daratumumab; the ELOQUENT-2 trial, which evaluated elotuzumab; the ASPIRE and ENDEAVOR trials, which evaluated carfilzomib; the TOURMALINE-MM trial, which evaluated ixazomib; the PANORAMA trial, which evaluated panobinostat; and the VANTAGE trial, which evaluated vorinostat.
For the analysis, patients were stratified by age younger than 65 years and age 65 years and older. Hazard ratios for benefit were calculated for the experimental and comparator arm for these two age groups. Though the number of patients over age 75 was small, hazard ratios were determined on an exploratory basis for that age group.
For the experimental arm relative to the comparator arm, all hazard ratios were statistically significant for patients less than age 65 with the exception of patients receiving elotuzumab in ELOQUENT-2. In that trial, the hazard ratio slightly exceeded the upward bound of the 95% confidence interval (95% CI, 0.55-1.02).
When the data were combined for the eight trials, the hazard ratio for PFS was 0.62 for newer agents relative to the comparator arms.
Similar results were seen for individual trial and aggregated trial data when the same calculations were done in patients aged 65-75. When the data for the eight trials were combined, the hazard ratio for PFS was 0.67 for newer agents relative to comparators.
The calculations for patients over age 75 were more limited because of the small numbers of trial participants in that age group. Of the hazard ratio estimates that were done, however, they were again of the same general magnitude seen in younger patients.
When PFS was broken down by type of therapy, the hazard ratios for patients younger than age 65 and those aged 65-75 were 0.57 and 0.52, respectively, for monoclonal antibodies. For combined data with the histone deacetylase inhibitors panobinostat and vorinostat, the respective hazard ratios were 0.67 and 0.78, respectively. For the second generation proteasome inhibitors carfilzomib and ixazomib, the respective hazard ratios were 0.61 and 0.70.
The ESMO-invited discussant for this presentation, Evangelos Terpos, MD, PhD, of the University of Athens, called the results reassuring. These data support treating relatively fit elderly patients with the newer agents.
“The data with the monoclonal antibodies suggest that these drugs actually provide their best results in elderly patients,” noted Dr. Terpos, pointing to the numerical advantage for the hazard ratio in older versus younger patients. The efficacy of monoclonal antibodies in older patients was further reinforced by the narrow confidence interval (95% CI, 0.42-0.61).
“There are many new drugs in the refractory setting [of multiple myeloma],” Dr. Terpos remarked. “It is helpful to have some data to show that these are also beneficial in the age group where this disease is most common.”
Dr. Landre agreed, noting that the median age at diagnosis of multiple myeloma is 69. This analysis helps to address the gap of “data available for evaluating efficacy in those older than 65 years and older than 75 years of age.”
