NEW ORLEANS—Clinical trials have yielded conflicting outcomes for lenalidomide maintenance (LM) therapy after induction therapy alone or post-autologous stem cell transplantation (ASCT) in patients with multiple myeloma (MM).

Now, a meta-analysis of data pooled from four randomized controlled trials representing 1,935 MM patients, shows “significant improvement in PFS (progression-free survival)” and a trend towards improvement in OS (overall survival) associated with LM. The analysis was presented at the 55th American Society of Hematology Annual Meeting and Exposition.

“Lack of uniform access to lenalidomide upon disease progression in the placebo/no maintenance arms of the constituent studies should be taken into account while interpreting aggregate effect estimates for overall survival,” cautioned Preet Paul Singh, MD, and colleagues at the Mayo Clinic in Rochester, MN. 

The authors also found an increased risk of grade 3/4 adverse events like neutropenia and thrombocytopenia, and second primary malignancies, and noted “considerable heterogeneity” between the five studies for overall survival rate estimates.

Nevertheless, they found “significant prolongation of both PFS (hazard ratio [HR], 0.491; 95% CI: 0.425-0.560; P < 0.001) and OS (HR, 0.77; 95% CI: 0.57-1.02; P = 0.07, not significant) with LM versus placebo/no maintenance.” 

The meta-analysis confirmed an increased risk of grade 3/4 adverse events with LM, including second primary malignancies (SPMs), the researchers reported.

“We observed a nearly 2-fold increase in the risk of SPMs with LM (odds ratio [OR], 3.2; P = 0.02),” they reported. “Patients on LM were more likely to have grade 3-4 AEs than placebo: neutropenia (OR, 4.9; P < 0.001), thrombocytopenia (OR, 2.7; P < 0.001), fatigue (OR, 2.3; P = 0.01), and venous thromboembolism (OR, 3.2; P = 0.02). Odds of discontinuing treatment were also significantly higher in patients on lenalidomide (OR, 2.9; P < 0.001).”

References

  1. Singh PP et al. Abstract #6407. Presented at: American Society of Hematology Meeting 2013. Dec. 7-10, 2013; New Orleans.