Background
Lenalidomide, bortezomib, and dexamethasone (RVD) is standard triplet induction for fit newly-diagnosed myeloma (NDMM) patients, with response rate (RR)>90%. A 21-day cycle with bortezomib given days 1, 4, 8, and 11 (2x/w) is standard. However, up to 80% of patients develop neuropathy. Weekly bortezomib dosing (1x/w), subcutaneous route, and 28- to 35-day cycle length may optimize tolerance. We present an effectiveness and toxicity analysis of Veterans who received RVD with 1x/w and 2x/w bortezomib for NDMM.
Methods
The VA Corporate Data Warehouse identified 1499 Veterans with NDMM given RVD ≤42 days of treatment start. 840 Veterans were grouped for initial analysis based on criteria: 1) lenalidomide and ≥ 3 bortezomib doses during cycle 1; 2) ≥6 mean days between bortezomib treatments=1x/w); and 3) number of lenalidomide days informed cycle length (21d, 28d, or 35d; default 7-day rest). Investigators reviewed algorithm results to finalize group assignments. Endpoints included depth of response, time to next treatment (TTNT), overall survival (OS), and neuropathy. Neuropathy was defined as use of neuropathy medications and neuropathy ICD-10 codes.
Results
Our algorithm correctly assigned 82% of 840 cycle 1 RVD schedules. The largest groups were 21d 1x/w (n=291), 21d 2x/w (n=193), 28d 1x/w (n=188), and 28d 2x/w (n=82). Median age was 68.3; 53% were non-Hispanic White. Demographics and ISS stage of groups were similar. 30% underwent autologous transplant. Tolerability. Median number of bortezomib doses ranged from 22.5-25.5 (p=0.57). Neuropathy favored 1x/w, 17.7 vs 30.2% (p=0.0001) and was highest (34.7%) in 21d 2x/w. Effectiveness. Response was assessable for 28% of patients. RR (72%, p=0.68) and median TTNT (19.3 months, p=0.20) were similar, including 1x/w vs 2x/w comparison (p=0.79). 21d regimens optimized TTNT (21.4 vs 13.9 months, p=0.045) and trended to better OS (73 vs 65 months, p=0.06).
Conclusions
1x/w RVD preserved effectiveness compared to “standard” RVD in a large Veteran cohort. 1x/w reduced neuropathy incidence. 28d regimens demonstrated inferior longer-term outcomes. Certain endpoints, such as RR and neuropathy, appear underestimated due to data source limitations. 21d 1x/w RVD optimizes effectiveness, tolerability, and administration and should be considered for broader utilization in Veterans with NDMM.