CHICAGO – Age and the results of select baseline lab measures reflected early response to initial therapy in a review of 1,304 newly diagnosed patients with symptomatic multiple myeloma.
Characteristics associated with increased odds of achieving very good partial response or better (VGPR+) within four cycles of treatment in the study participants, who were seen between 2001 and 2013, were absolute free light chain difference of more than 175 mg/dL (odds ratio, 2.38), age less than 75 years at diagnosis (OR, 2.18), hemoglobin concentration less than 10/12.5 (OR, 1.68), and IgA vs. IgG serum heavy chain secretion (OR, 1.66), Dr. Moritz Binder of the Mayo Clinic, Rochester, Minn., reported in a poster at the American Society of Hematology Meeting on Hematologic Malignancies.
Dr. Moritz Binder
In patients receiving proteasome inhibitors, better response was associated with creatinine concentrations greater than 1.5 mg/dL (OR, 3.83), calcium concentration less than 9.0 mg/dL (OR, 3.37), and greater absolute free light chain difference greater than 175 mg/dL (OR, 2.50), Dr. Binder noted.
High-risk cytogenetic features, conversely, were not associated with treatment response, he said.
The findings are important because the initial response to therapy in newly diagnosed disease can have an effect on long-term outcomes; achieving at least a VGPR to initial treatment can improve progression-free and overall survival. Further, novel agents and risk-adapted treatment strategies now in use have improved response rates and overall survival, Dr. Binder said, adding that it has been unclear, however, whether baseline laboratory parameters could predict the likelihood of early, deep response to initial therapy.
“The ability to predict the likelihood of response to the current therapies can have implications for the treatment approaches in NDMM,” he wrote.
In this study, 288 patients achieved VGPR+ after 4 months, and those patients had a decreased risk of subsequent mortality (hazard ratio, 0.69). This remained true after adjusting for sex, age, International Staging System stage, bone marrow plasma cell involvement, lactate dehydrogenase concentration, initial treatment regimen group, and hematopoietic stem cell transplantation during the disease course (HR, 0.68), he said.
The three most common regimens with immunomodulators that were used in the cohort were lenalidomide-dexamethasone, thalidomide-dexamethasone, and cyclophosphamide-lenalidomide-dexamethasone, and the three most common regimens with proteasome inhibitors were bortezomib-cyclophosphamide-dexamethasone, bortezomib-lenalidomide-dexamethasone, and bortezomib-dexamethasone.
Dr. Binder reported receiving research funding from ASH. Coauthors reported receiving research funding from Celgene, Janssen, Millennium, and Pfizer, and/or serving in an advisory role for Pfizer.