Receipt of triplet therapy was associated with the best survival outcomes among patients with multiple myeloma (MM) aged 75 or older, according to the results of a recent study. These patients had a 35% reduction in risk for death compared with patients that received other treatments.
The retrospective study looked at 394 patients aged 75 or older treated for newly diagnosed MM at Mayo Clinic, Rochester, Minn. from January 2004 to January 2018. Patients had been treated as part of a clinical trial (11%) or outside of a clinical trial.
About one-third of patients (31%) had been treated with an immunomodulatory agent plus dexamethasone (IMiD + dex). Other common treatments were alkylator plus steroid (19%), an alkylator plus proteasome inhibitor (PI) plus steroid (17%), and an IMiD plus PI plus dexamethasone (13%).
Achieving a very good partial response or better was more likely among those patients treated with a triplet compared to other therapies (46% vs. 21%; P<.0001). In addition, receipt of triplet therapy was associated with a longer median overall survival (median 50.2 vs. 32.8 months; P<.0006).
On multivariate analysis, the researchers identified several factors associated with improved overall survival including receipt of triplet therapy (hazard ratio [HR], 0.65; P = 0.02), not having an R-ISS stage 3 (HR, 0.36; P = 0.0003), and bone marrow plasma cell percentage less than 60% (HR, 0.69; P = 0.03).
“Patients >75 years old have less bone marrow reserve and are more likely to have cytopenias than younger patients. In addition, they are more likely to have co-morbidities that can decrease the tolerability of treatment,” the researchers wrote. “However, overall the progression-free survival and overall survival reported in our study is in the range of the reported survival for elderly transplant ineligible patients.”
The researchers acknowledged several limitations including a lack of data on toxicity of the combination regimens, lack of frailty assessments, and lack of data on other comorbidities. Because of this, they cannot “fully explain the reasons for better outcomes in patients who received triplet therapy”.