The phase 3 MAIA study evaluated D-Rd versus Rd in 737 patients who were ineligible for high-dose chemotherapy and autologous stem cell transplantation. The primary analysis of MAIA demonstrated a 44% reduction in the risk of disease progression or death after treatment with D-Rd compared with Rd alone. At a median follow-up of almost 5 years (56.2 months), we now report the pre-specified interim overall survival analysis of MAIA according to the results presented at the European of Hematology Association (EHA) annual meeting, held virtually from from 9 to 17 June.
The addition of daratumumab to Rd treatment significantly reduced the risk of death by 32% (hazard ratio, 0.68; 95% confidence interval [CI], 0.53-0.86; P=0.0013) with an estimated 5-year overall survival rate of 66.3% in the D-Rd group compared with 53.1% in the Rd alone group. These results are despite 46% of patients who received subsequent therapy in the Rd arm receiving daratumumab. Similarly, the significant progression-free survival benefit of D-Rd versus Rd that was identified in the primary analysis was maintained, with a 47% reduction in the risk of disease progression or death (HR, 0.53; 95% CI, 0.43-0.66; P<0.0001) and an estimated 60-month progression-free survival rate of 52.5% versus 28.7%, respectively; these data provide a new PFS benchmark for patients with NDMM who are transplant ineligible. The high overall response rate (93% vs 82%) further demonstrated the added clinical benefit of D-Rd versus Rd alone.
No new safety concerns were identified for D-Rd and the most common (>15%) grade 3/4 treatment-emergent adverse events for D-Rd and Rd were neutropenia (54% vs 37%), pneumonia (19% vs 11%), anemia (17% vs 22%), and lymphopenia (16% and 11%). In conclusion, the clinical benefit from the primary analysis of the MAIA study was maintained through 5 years of follow-up and the benefit of upfront D-Rd given to progression was confirmed with a significant OS improvement, further supporting the use of frontline daratumumab as a new standard of care for patients with transplant-ineligible NDMM.