Post-transplant consolidation plus lenalidomide maintenance vs lenalidomide maintenance alone in multiple myeloma: A systematic review.

BACKGROUND: In newly diagnosed multiple myeloma (NDMM), autologous stem cell transplantation (ASCT) remains the standard approach for transplant-eligible patients. To control the inevitable relapse, post-transplant consolidation/maintenance strategies are commonly used. However, the benefit of post-transplant consolidation is still uncertain METHOD: We conducted a systematic review of phase II/III studies to compare the efficacy of post-ASCT consolidation plus lenalidomide maintenance (CON+LEN) vs lenalidomide maintenance alone (LEN alone) in NDMM. A meta-analysis using fixed and random effects models was performed.

RESULTS: Fourteen studies were included with 2275 participants with NDMM treated with ASCT and lenalidomide maintenance. Two groups were identified: CON+LEN group (n = 1102) and LEN alone group (n = 1173). There was no statistically significant difference in the complete response rate between the two groups [RR = 1.1; 95% CI: 0.83-1.44; P = .490]. Interestingly, we found that very good partial response or better rate is around 1.5-fold significantly higher in the CON+LEN group compared to LEN alone group [RR: 1.46; 95% CI: 1.25-1.70; P < .0001]. However, there was no significant difference between the two groups regarding PFS [RR: 1.0; 95% CI: 0.92-1.08, P = .929] and OS [RR: 0.9; 95% CI: 0.92-1.01; P = .148] at 3-4 years follow-up. The risk of secondary primary malignancy (SPM) was also similar between the two groups (RR: 1.2; 95% CI: 0.84-1.92; P = .2). Data on adverse events were limited.

CONCLUSION: Our data suggest that, in NDMM patients treated with upfront ASCT, post-transplant consolidation may improve depth of response, but does not add to OS or PFS, compared to lenalidomide maintenance alone. However, data in this context are still immature.