Table 2 Methodology and findings of published flow cytometry-based MRD studies in AL amyloidosis and of the present report.
Study | NGF technique | Sensitivity | N. pts | Pts. in CR N (%) | ASCT N (%) | Eligibility criteria | Median time from CR to MRD assessment | MRDpos N (%) | Median follow-up from MRD assessment | % Hematologic progression POS vs NEG | Cardiac response N/evaluable (%) POS vs NEG | Renal response N/evaluable (%) POS vs NEG |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Kastritis et al.24 | EuroFlow | Range: 2–3.1 × 10−6 Median 2.3 × 10−6 | 20 | 20 (100%) | 8 (40%) | CR+ negative BM biopsy | 36 months | 12 (60%) | NA | NA | 1/4(25%) vs 3/3(100%) | 6/10(60%) vs 6/8 (75%) |
Muchtar et al.26 | 7-color MFC | Range: 1 × 10−4–2 × 10−5 | 82 | 16 (20%) | 69 (84%) | End of first-line treatment | NA | 58 (71%)a Subgroup of CR pts.: 8 (50%) | NA | 3-year PFS: 28% vs 88% Subgroup of CR pts.: 33% vs 100% | Subgroup of VGPR/CR pts.: 10/12 (83%) vs 8/8 (100%) | Subgroup of VGPR/CR pts.: 13/19 (68%) vs 14/14 (100%) |
Sidana et al.25 | Euroflow | Range: ≥1 × 10−5–10−6 | 44 | 20 (45%) | 25 (57%) | MRD testing within 2 years from start of therapy | NA | 14 (36%)b Subgroup of CR pts.: 5 (25%) | 14 months | Estimated 1-year PFS: 64% vs 100% | 2/7 (22%) vs 8/12 (67%) | 8/9 (89%) vs 11/16 (69%) |
Staron et al.28 | 2-tube, 10-color antibody panel | Range: 1 × 10−4–1 × 10−5 | 65 | 65 (100%) | 32 (49%) | CR at previous evaluation | 71 months for MRD negative 32 months for MRD positive | 36 (55%) | NA | NA | 10/17 (59%) vs 9/12 (75%) | 18/28 (64%) vs 21/24 (88%) |
Kastritis et al.27 | Euroflow | Range: 2 × 10−6–3.1 × 10−6 | 52 | 52 (100%) | 7 (14%) | CR after their primary therapy | 6 months (range 3–12) | 28 (55%) | 24 months | 21% vs 0% | 11/15 (73%) vs 10/10 (100%) | 14/16 (87.5%) vs 15/17 (88%) |
Current study | Euroflow | 10−6: 76% 10−5: 24% | 92 | 92 (100%) | 35 (38%) | CR confirmed at least 6 months after end of therapy | MRD pos: 13 months; MRD neg: 12 months | 50 (54%) | 23 months | 26% vs 2% | 18/19 (95%) vs 20/28 (71%) | 23/25 (92%) vs 15/26 (57%) |
