Characteristics of the study group (n = 261) and historical control group (n = 251)
Characteristic . | Imatinib mesylate . | Historical control . | P . |
|---|---|---|---|
| No. | 261 | 251 | NA |
| Age at least 60 y | 90 (34%) | 42 (17%) | < .0001 |
| Splenomegaly | 27 (10%) | 36 of 170 (21%) | .003 |
| Mos from diagnosis to therapy | |||
| Median | 33 | 26 | .002 |
| Less than 12 | 28 (11%) | 41 (16%) | |
| 12 to 35 | 110 (42%) | 130 (52%) | |
| 36 or more | 123 (47%) | 80 (32%) | |
| Hemoglobin level less than 12.0 g/dL | 100 (38%) | 127 of 241 (53%) | .002 |
| White blood cell count | |||
| Less than 10 × 109/L | 135 (52%) | 66 of 235 (28%) | < .0001 |
| 10 × 109/L to 50 × 109/L | 102 (39%) | 115 of 235 (49%) | |
| More than 50 × 109/L | 24 (9%) | 54 of 235 (23%) | |
| Platelet count | |||
| 450 × 109/L to 700 × 109/L | 38 (15%) | 30 of 240 (12%) | .42 |
| More than 700 × 109/L | 21 (8%) | 27 of 240 (11%) | |
| Peripheral blasts present | 45 (17%) | 50 of 232 (22%) | .27 |
| Marrow blasts at least 5% | 25 (10%) | 16 of 182 (9%) | .91 |
| Peripheral basophils at least 7% | 30 (11%) | 31 of 233 (13%) | .64 |
| Marrow basophils at least 5% | 33 (13%) | 17 of 181 (9%) | .36 |
| Ph 90% or less before therapy | 72 (28%) | 22 of 186 (12%) | < .0001 |
| Additional chromosomal abnormalities other than Ph variants or loss of Y | 24 (9%) | 26 of 184 (14%) | .14 |
| IFN-α last response | |||
| Hematologic resistance | 22 (8%) | 51 (20%) | < .0001 |
| Hematologic relapse | 13 (5%) | 24 (10%) | |
| Cytogenetic resistance | 126 (48%) | 122 (49%) | |
| IFN-α intolerance | 100 (38%) | 54 (22%) |
Characteristic . | Imatinib mesylate . | Historical control . | P . |
|---|---|---|---|
| No. | 261 | 251 | NA |
| Age at least 60 y | 90 (34%) | 42 (17%) | < .0001 |
| Splenomegaly | 27 (10%) | 36 of 170 (21%) | .003 |
| Mos from diagnosis to therapy | |||
| Median | 33 | 26 | .002 |
| Less than 12 | 28 (11%) | 41 (16%) | |
| 12 to 35 | 110 (42%) | 130 (52%) | |
| 36 or more | 123 (47%) | 80 (32%) | |
| Hemoglobin level less than 12.0 g/dL | 100 (38%) | 127 of 241 (53%) | .002 |
| White blood cell count | |||
| Less than 10 × 109/L | 135 (52%) | 66 of 235 (28%) | < .0001 |
| 10 × 109/L to 50 × 109/L | 102 (39%) | 115 of 235 (49%) | |
| More than 50 × 109/L | 24 (9%) | 54 of 235 (23%) | |
| Platelet count | |||
| 450 × 109/L to 700 × 109/L | 38 (15%) | 30 of 240 (12%) | .42 |
| More than 700 × 109/L | 21 (8%) | 27 of 240 (11%) | |
| Peripheral blasts present | 45 (17%) | 50 of 232 (22%) | .27 |
| Marrow blasts at least 5% | 25 (10%) | 16 of 182 (9%) | .91 |
| Peripheral basophils at least 7% | 30 (11%) | 31 of 233 (13%) | .64 |
| Marrow basophils at least 5% | 33 (13%) | 17 of 181 (9%) | .36 |
| Ph 90% or less before therapy | 72 (28%) | 22 of 186 (12%) | < .0001 |
| Additional chromosomal abnormalities other than Ph variants or loss of Y | 24 (9%) | 26 of 184 (14%) | .14 |
| IFN-α last response | |||
| Hematologic resistance | 22 (8%) | 51 (20%) | < .0001 |
| Hematologic relapse | 13 (5%) | 24 (10%) | |
| Cytogenetic resistance | 126 (48%) | 122 (49%) | |
| IFN-α intolerance | 100 (38%) | 54 (22%) |
NA indicates not applicable.