Table 2.
Characteristics of all FLT3-ITD clones detected at diagnosis and disease progression with or without midostaurin treatment
| Variable | Midostaurin (n = 54) | No midostaurin (n = 21) | Midostaurin vs no midostaurin | |||||
|---|---|---|---|---|---|---|---|---|
| Diagnosis | Disease progression | P | Diagnosis | Disease progression | P | P diagnosis | P progression | |
| Patients with multiple ITDs | ||||||||
| n (%) | 15 (28) | 5 (9) | .02 | 4 (19) | 2 (10) | .67 | .56 | .60 |
| Total number of ITDs | ||||||||
| n | 74 | 33 | ND | 21 | 15 | ND | ND | ND |
| FLT3-ITD AR | ||||||||
| Median (range) | 0.49 (0.05-4.32) | 0.39 (0.05-26.31) | .30 | .71 (0.05-18.94) | 1.00 (0.05-38.75) | .28 | .10 | .002 |
| FLT3-ITD nt length | ||||||||
| Median (range) | 54 (18-225) | 54 (18-162) | .57 | 33 (15-81) | 30 (18-72) | .31 | .002 | .001 |
| FLT3-ITD insertion site | .68 | .65 | .04 | .12 | ||||
| JMD | 44 (59) | 18 (55) | 18 (86) | 12 (80) | ||||
| JM-Z | 29 (39) | 11 (33) | 15 (71) | 9 (60) | ||||
| JM-S | 2 (3) | 0 (0) | 0 (0) | 0 (0) | ||||
| Hinge region | 13 (18) | 7 (22) | 3 (14) | 3 (20) | ||||
| TKD1 | 30 (41) | 15 (45) | 3 (14) | 3 (20) | ||||
| Beta1-sheet | 29 (39) | 14 (42) | 3 (14) | 3 (20) | ||||
| Nucleotide binding loop | 1 (2) | 1 (3) | 0 (0) | 0 (0) | ||||
| FLT3-ITD status at disease progression* | ||||||||
| FLT3-ITD positive | 54 (100) | 29 (54) | ND | 12 (100) | 17 (81) | ND | ND | .04 |
| Identical clones | NA | 17 (31) | ND | NA | 6 (40) | ND | ND | |
| Change ITD clones | NA | 12 (22) | ND | NA | 7 (47) | ND | ND | |
| Switch ITD | NA | 4 (7) | NA | 4 (27) | ||||
| Gain ITD clones | NA | 2 (4) | NA | 1 (7) | ||||
| Loss ITD clones | NA | 6 (11) | NA | 2 (13) | ||||
| No ITD detectable | NA | 25 (46) | ND | NA | 4 (19) | ND | ND | .04 |
JMD, juxtamembrane domain; NA, not available; ND, not determined; nt, nucleotide.
*
FLT3-ITD insertion sites not available for 4 patients.