Table 1.
Demographic and clinicopathological characteristics of the training and validation cohorts.
| Variables | Overall (n = 302) | Training cohort (n = 211) | Validation cohort (n = 91) | p-value |
|---|---|---|---|---|
| Age (years) | 57 (34–76) | 57 (34–73) | 56 (39–76) | 0.816 |
| Gender, male | 166 (54.9) | 113 (53.6) | 53 (58.2) | 0.52 |
| R-ISS stage III | 179 (59.3) | 123 (58.3) | 56 (61.5) | 0.612 |
| Type of myeloma, IgG | 185 (61.3) | 136 (64.5) | 49 (53.8) | 0.095 |
| Type of CAR-T cell therapy | ||||
| BCMA | 64 (21.2) | 49 (23.2) | 15 (16.5) | 0.189 |
| GPRC5D | 71 (23.5) | 54 (25.6) | 17 (18.7) | |
| BCMA+CD19 | 135 (44.7) | 87 (41.2) | 48 (52.7) | |
| BCMA+GPRC5D | 32 (10.6) | 21 (9.9) | 11 (12.1) | |
| High tumor burdena | 87 (28.8) | 56 (26.5) | 31 (34.1) | 0.213 |
| High-risk cytogenetic featuresb | 73 (24.2) | 54 (25.6) | 19 (20.9) | 0.464 |
| Extramedullary lesionsc | 107 (35.4) | 77 (36.5) | 30 (32.9) | 0.601 |
| Previous HCT | 99 (32.8) | 63 (29.9) | 36 (39.6) | 0.109 |
| Previous therapy lines | 4 (2–14) | 4 (2–14) | 4 (2–10) | 0.719 |
| Neutrophil count, × 109/L | 2.1 (1.3–3.9) | 2.3 (1.5–3.8) | 2.2 (1.2–3.1) | 0.425 |
| Hemoglobin, g/L | 95 (83–109) | 93 (87–112) | 96 (88–118) | 0.54 |
| Platelet count, × 109/L | 109 (76–154) | 106 (73–146) | 110 (75–152) | 0.082 |
| Ferritin, ng/ml | 362.8 (218.2–819.3) | 353.2 (216–805.1) | 349 (221.1–796) | 0.109 |
| CRP, mg/L | 5 (0.6–10) | 5 (0.6–10) | 5 (0.8–9) | 0.315 |
| IL-6, pg/ml | 7 (2.8–12) | 7 (5–10) | 6 (3.1–8) | 0.207 |
| IL-8, pg/ml | 5.2 (2.2–19.5) | 5 (1.98–21.3) | 5.4 (1.79–18.9) | 0.481 |
| IL-10, pg/ml | 3.1 (1.8–6) | 2.9 (1.6–5.7) | 3.4 (1.3–5.4) | 0.282 |
| INF-α, pg/ml | 4 (1.5–8.9) | 4.3 (1.2–10) | 4.1 (1.6–9.5) | 0.724 |
| INF-γ, pg/ml | 7.3 (3.2–23.1) | 7.5 (3.7–22.5) | 7.2 (3.5–20.6) | 0.314 |
| LDH, U/L | 205 (192–351) | 198 (182–347) | 187 (172–358) | 0.207 |
| BMI, kg/m2 | 22.5 (19.3–28.3) | 22.5 (19–28.1) | 23.1 (19.3–27.8) | 0.38 |
| CONUT score | 4 (2–6) | 4 (2–6) | 4 (2–6) | 0.417 |
Characteristics are summarized as median (interquartile ranges) or frequency (%).
aHigh tumor burden: defined as ≥50% clonal plasma cells or bone marrow plasma cells.
bHigh-risk cytogenetics was reported by investigators based on fluorescence in situ hybridization. A high-risk cytogenetic profile was defined by the presence of the following abnormalities: del(17p), t (4;14), or t (14; 16).
cExtramedullary diseases included tissue masses in extraosseous locations and bone-related plasmacytomas.