Study Design
Open-label, multicenter, randomized phase III trial (NCT03301220). Enrolled 390 patients with high-risk SMM, randomized 1:1 to: Subcutaneous daratumumab (with hyaluronidase) for up to 36 months. Active monitoring (observation) . Key criteria: ≥10% clonal plasma cells, along with other high-risk features such as high M-protein, immunoparesis, or abnormal free light chain ratio .
Primary Endpoint: Progression-Free Survival (PFS)
After a median follow-up of 65.2 months (~5.5 years): Median PFS: Daratumumab arm: not reached. Active monitoring arm: 41.5 months. Hazard ratio (HR): 0.49 (95% CI: 0.36–0.67); p < 0.001 — signifying a 51% reduction in risk of progression or death . 5-year PFS rates: Daratumumab: 63.1% Monitoring: 40.8% .
Overall Survival (OS)
5-year OS: Daratumumab: 93.0% Monitoring: 86.9% HR: 0.52 (95% CI: 0.27–0.98) . While not the primary endpoint, this indicates an OS benefit, though the trial was not specifically powered for OS .
Response Rates & Time to First-Line Treatment
Overall Response Rate (ORR): Daratumumab: ~63.4% Monitoring: ~2.0% . Initiation of first-line multiple myeloma treatment by 5 years: Daratumumab: ~29.7% Monitoring: ~55.9% (HR: 0.46; 95% CI: 0.33–0.62) .
Safety and Tolerability
Grade 3–4 adverse events (AEs): More frequent with daratumumab (40.4%) compared to monitoring (30.1%) . Most common serious AEs: Hypertension: 5.7% (daratumumab) vs. 4.6% (monitoring). Infections: 16.1% vs. 4.6%; pneumonia: 3.6% vs. 0.5% . Treatment discontinuation due to AEs: 5.7% in daratumumab group . No new safety signals were identified, and quality of life remained stable .
Regulatory Insights
The FDA’s advisory committee (ODAC) voted in favor of a favorable risk-benefit profile for daratumumab SC in high-risk SMM. A concern was raised regarding evolving definitions of “high-risk” SMM, noting that only ~41% of current high-risk patients (per modern criteria) would have fit the trial’s criteria, potentially limiting applicability .
Clinical Significance
Largest Phase III trial in high-risk SMM to date, showing durable PFS and OS benefit with fixed-duration monotherapy . Unlike prior studies (e.g., QuiRedex or ECOG E3A06), AQUILA demonstrates both survival advantage and favorable tolerability—potentially establishing daratumumab monotherapy as a new standard of care for high-risk SMM
