Table 1.
Baseline clinical characteristics of patients treated with or without a FLT3 inhibitor-based therapy
| Characteristics | No FLT3i Cohort N= 30 N (%) [range] |
FLT3i Cohort N= 20 N (%) [range] |
p |
|---|---|---|---|
| Median age, years | 67 [23–84] | 58 [28–83] | 0.03 |
| Age >60 years old | 24 (80) | 8 (40) | 0.04 |
| Male gender | 17 (57) | 10 (50) | 0.64 |
| Type of AML | |||
| De novo | 25 (83) | 20 (100) | 0.16 |
| Secondary AML | 1 (3) | 0 (0) | |
| Therapy related | 4 (14) | 0 (0) | |
| WBC, x109/L | 5.2 [1.1–34.2] | 5.8 [0.9–378.4] | 0.44 |
| Hemoglobin, g/dl | 8.9 [7.7–11.6] | 8.7 [5.1–11.4] | 0.37 |
| Platelets, x109/L | 52 [9–222] | 31 [10–96] | 0.33 |
| Creatinine | 0.8 [0.5–1.4] | 0.7 [0.5–4.6] | 0.69 |
| Total Bilirubin | 0.7 [0.2–1. | 0.5 [0.3–1.3] | 0.08 |
| Peripheral blood blasts, % | 24 [0–91] | 19 [0–97] | 0.86 |
| Bone marrow blasts, % | 64 [15–96] | 72 [30–94] | 0.43 |
| Cytogenetics | |||
| Diploid karyotype | 15 (50) | 12 (60) | 0.77 |
| Adverse | 7 (23) | 4 (20) | |
| others | 8 (27) | 4 (20) | |
| FLT3 mutations* | |||
| ITD Allelic Frequencies | 0.03 [0.01–0.09] | 0.05 [0.01–0.09] | 0.45 |
| Other Mutations | |||
| NPM1 | 9/28 (32) | 12/20 (60) | 0.06 |
| RUNX1 | 7/21 (33) | 3/19 (16) | 0.20 |
| RAS | 5/27 (18) | 6/20 (30) | 0.36 |
| IDH2 | 8/29 (28) | 5/20 (25) | 0.84 |
| ASXL1 | 5/21 (24) | 2/19 (11) | 0.27 |
| IDH1 | 6/29 (21) | 1/19 (5) | 0.12 |
| DNMT3A | 2/27 (7) | 1/20 (5) | 0.74 |
| CEBPA | 1/26 (4) | 3/19 (16) | 0.16 |
| TP53 | 1/24 (4) | 1/19 (5) | 0.87 |
| Treatment | |||
| Low Intensity | 17 (57) | 4 (20) | 0.01 |
| High Intensity | 13 (43) | 16 (80) | |
| FLT3 inhibitors | |||
| Sorafenib | 0 (0) | 19 (96) | n/a |
| Quizartinib | 0 (0) | 1 (5) | |
| no FLT3i | 30 (100) | 0 (0) | |
| Treatment outcome | |||
| CR + CRi | 20 (67) | 17 (85) | 0.23 |
| No response | 7 (23) | 3 (15) | |
| Early death | 3 (10) | 0 (0) | |
| ASCT in CR1 | 8 (27) | 6 (20) | 0.80 |
FLT2 inhibitor; N, number; n/a, not applicable; WBC, white blood cell; CR/CRi, complete remission/Complete remission with incomplete count recovery; ASCT, allogeneic stem cell transplant; CR1, first remission
*
Only 1 patient had both ITD and D835 at baseline, others were isolated FLT-ITD
Response definitions were per international working group (IWG) criteria. Relapse is defined by the detection of blasts (>5%) in a bone marrow aspirate or by the detection of biopsy-proven extramedullary myeloid sarcoma