Table 2.
Hematologic and Cytogenetic Response Rates Before and After Crossover
| No. of Patients (%) | ||||
|---|---|---|---|---|
| Initial Treatment | Postcrossover | |||
| Response | Dasatinib, n=101 | High-Dose Imatinib, n=49 | From High-Dose Imatinib to Dasatinib, n=39 | From Dasatinib to High-Dose Imatinib, n=20 |
| Complete hematologic response | 94 (93)* | 40 (82) | 37 (95) | 13 (65) |
| 95% CI | 86.2–97.2 | 68–91.2 | 82.7–99.4 | 40.8–84.6 |
| Cytogenetic responses | ||||
| MCyR at 12 wk | 36 (36)† | 14 (29) | ||
| 95% CI | 26.4–45.8 | 16.6–43.3 | — | — |
| CCyR at 12 wk | 22 (22)‡ | 4 (8) | — | — |
| MCyR | 54 (53)§ | 16 (33) | 19 (49) | 3 (15) |
| 95% CI | 43.3–63.5 | 19.9–47.5 | 32.4–65.2 | 3.2–37.9 |
| Previous imatinib, 600 mg/d | 32/63 (51) | 8/34 (24) | — | — |
| Previous imatinib, 400 mg/d | 22/36 (61) | 7/14 (50) | — | — |
| CCyR | 44 (44)|| | 9 (18) | 15 (38) | 0 (0) |
| PCyR | 10 (10) | 7 (14) | 4 (10) | 3 (15) |
| MCyR in patients with previous | ||||
| CyR on imatinib | ||||
| All | 34/62 (55) | 15/34 (44) | — | — |
| Previous imatinib, 600 mg/d | 20/40 (50) | 8/23 (35) | ||
| Previous imatinib, 400 mg/d | 14/20 (70) | 6/10 (60) | ||
| MCyR in patients without a previous | ||||
| CyR on imatinib | ||||
| All | 20/39 (51) | 1/15 (7) | ||
| Previous imatinib, 600 mg/d | 12/23 (52) | 0/11 (0) | ||
| Previous imatinib, 400 mg/d | 8/16 (50) | 1/4 (25) | ||
| Cytogenetic response by imatinib resistance¶ | — | — | ||
| Primary resistance | n=53 | n=24 | — | — |
| MCyR | 30 (57) | 7 (29) | ||
| CCyR | 22 (42) | 3 (13) | ||
| Acquired resistance | n=43 | n=24 | — | — |
| MCyR | 21 (49) | 8 (33) | ||
| CCyR | 19 (44) | 5 (21) | ||
| Cytogenetic response with protocol-specified mutations# | n=17 | n=2 | — | — |
| MCyR | 7 (41) | 0 (0) | ||
| CCyR | 4 (24) | 0 (0) | ||
95% CI indicates 95% confidence interval; MCyR, major cytogenetic response; CCyR, complete cytogenetic response; PCyR, partial cytogenetic response; CyR, any cytogenetic response.
*
P =.0341.
†
P =.402.
‡
P =.041.
§
P =.017.
||
P =.0025.
¶
Six patients had no reason for previous imatinib resistance available.
#
Patients with protocol-specified mutations, including L248V, G250E, Q252H/R, Y253H/F, E255K/V, T315I/D, F317L, and H396P/R.