Maintenance therapy in transplant ineligible adults with newly-diagnosed multiple myeloma: a systematic review and meta-analysis.

BACKGROUND The role of maintenance therapy in transplant ineligible multiple myeloma (MM) patients following a period of fixed duration induction therapy remains unclear. OBJECTIVES We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) examining maintenance therapy compared to observation. METHODS We conducted a comprehensive search including MEDLINE, Embase and the Cochrane database up to February 28, 2020 for RCTs comparing maintenance therapy to observation in newly-diagnosed transplant ineligible MM patients. Two authors independently screened studies for eligibility, extracted data, and assessed risk of bias. We performed meta-analyses using a random-effects model and assessed certainty using GRADE methodology. MAIN RESULTS We included five RCTs with a total of 1139 patients. Patients receiving maintenance therapy had improved progression free survival (PFS) compared to observation (Hazard ratio [HR] 0.48, 95% Confidence Interval [CI] 0.38 to 0.62, high certainty); however, there was no difference in overall survival (HR 0.96, 95% CI 0.76 to 1.2, moderate certainty). Adverse events were higher in the maintenance group compared to observation (very low to moderate certainty). CONCLUSION Maintenance therapy increases PFS in transplant ineligible MM patients following a fixed period of induction therapy; however, this must be weighed against the increased risk of adverse events.