Table 1.
Characteristics of the 39 patients enrolled in the observational study.
| Characteristics | n (%) |
|---|---|
| Total Patients | 39 |
| Sex | |
| Male | 22 (56.4) |
| Female | 17 (43.6) |
| Age at initial diagnosis | |
| Median, years (IQR) | 5.3 (0.2–20.4) |
| <12 months | 3 (7.7) |
| 1–18 years | 35 (89.7) |
| >18 years | 1 (2.6) |
| Immunophenotype | |
| pre-B (EGIL B-I) | 8 (20.5) |
| Common (EGIL B-II) | 27 (69.2) |
| pro-B (EGIL B-III) | 4 (10.3) |
| Karyotype | |
| Hyperdiploid | 7 (17.9) |
| t (12; 21) | 1 (2.6) |
| t (3; 9) | 1 (2.6) |
| Other chromosomal aberrations | 3 (7.7) |
| Normal karyotype | 9 (23.1) |
| Unknown cytogenetic status | 18 (46.1) |
| Molecular abnormalities | |
| iAMP21 | 1 (2.6) |
| Ph-like | 2 (5.1) |
| KMT2A-rearrangement | 4 (10.3) |
| Absence of mutations | 24 (61.5) |
| Unknown mutational status | 8 (20.5) |
| First-line risk stratification | |
| Standard Risk | 4 (10.3) |
| Medium Risk | 13 (33.3) |
| High risk | 15 (38.5) |
| Unknown | 7 (17.9) |
| Months from diagnosis to blinatumomab treatment | |
| Median (IQR) | 6 (0.7–20.1) |
| <18 months | 9 (23.1) |
| 18 months–30 months | 8 (20.5) |
| >30 months | 22 (56.4) |
| Age at treatment | |
| Median, years (IQR) | 9.2 (2.3–21.5) |
| <12 months | 0 (0) |
| 1–18 years | 36 (92.3) |
| >18 years | 3 (7.7) |
| Therapeutic line | |
| Front line | 4 (10.2) |
| First relapse | 23 (59) |
| Second or greater relapse | 12 (30.8) |
| Refractory | 4 (10.2) |
| Relapses | 35 (89.7) |
| Site of relapse | |
| Bone Marrow | 24(68.5) |
| Molecular relapse | 3(8.6) |
| Combined relapse | 8 (22.9) |
| HSCT pre blinatumomab | |
| Yes | 10 (25.6) |
| No | 29 (74.4) |
| Blinatumomab courses | |
| 1 | 17 (43.6) |
| 2 | 18 (46.2) |
| >2 | 4 (10.2) |
| Bone marrow blasts before blinatumomab <5% | 26 (66.7) |
| After debulking chemotherapy | 18 (46.2) |
| PCR-MRD positive | 5 (12.8) |
| FC-MRD positive | 3 (7.7) |
| Bone marrow blasts before blinatumomab ≥5% | 13 (33.3) |
| >5–25% blasts | 6 (15.4) |
| >25% blasts | 7 (17.9) |
IQR: Interquartile Range; EGIL: European Group for the Immunological Characterization of Leukemias; iAMP21: intrachromosomal amplification of chromosome 21; HSCT: Hematopoietic Stem Cell Transplantation.