Two-Year HbF Change by Baseline and Follow-Up Characteristics
| . | Hydroxyurea . | Placebo . | Int P . | |||||
|---|---|---|---|---|---|---|---|---|
| . | n . | Mean . | SD . | P . | n . | Mean . | SD . | . |
| Overall | 143 | 3.6 | 5.4 | 135 | −0.4 | 2.0 | — | |
| Baseline | ||||||||
| Male | 74 | 3.0 | 4.8 | 71 | −0.4 | 2.5 | ||
| Female | 69 | 4.1 | 5.9 | .22 | 64 | −0.4 | 4.1 | .27 |
| 0 CAR6-150 | 95 | 4.3 | 5.6 | 96 | −0.4 | 1.8 | ||
| 1-2 CAR | 48 | 2.3 | 4.8 | .04 | 39 | −0.3 | 2.6 | .05 |
| L,L/H FCP6-150 | 130 | 3.4 | 5.5 | 127 | −0.3 | 2.1 | ||
| H/H FCP6-151 | 13 | 4.7 | 5.4 | .43 | 8 | −1.1 | 1.2 | .27 |
| Retic < 300K6-152 | 58 | 1.8 | 3.8 | 59 | 0.0 | 2.1 | ||
| Retic ≥ 300K | 85 | 4.8 | 6.0 | .001 | 77 | −0.7 | 2.0 | .0001 |
| Neuts < 7.5Kρ | 94 | 2.7 | 4.8 | 89 | −0.4 | 2.2 | ||
| Neuts ≥ 7.5K | 49 | 5.3 | 6.3 | .006 | 47 | −0.4 | 1.8 | .01 |
| HbF < 7.5% | 116 | 3.2 | 5.2 | 107 | −0.3 | 1.5 | ||
| HbF ≥ 7.5% | 27 | 5.3 | 6.2 | .07 | 29 | −0.9 | 3.4 | .03 |
| Follow-up | ||||||||
| <80% Adh6-154 | 39 | 2.0 | 5.0 | 42 | −0.3 | 2.0 | ||
| ≥80% Adh | 104 | 4.2 | 5.5 | .03 | 93 | −0.4 | 2.1 | .02 |
| 0-1 toxic6-155 | 41 | 0.6 | 3.8 | 111 | −0.4 | 2.2 | ||
| 2+ toxic | 112 | 4.8 | 5.5 | .0001 | 24 | −0.5 | 1.5 | .0002 |
| . | Hydroxyurea . | Placebo . | Int P . | |||||
|---|---|---|---|---|---|---|---|---|
| . | n . | Mean . | SD . | P . | n . | Mean . | SD . | . |
| Overall | 143 | 3.6 | 5.4 | 135 | −0.4 | 2.0 | — | |
| Baseline | ||||||||
| Male | 74 | 3.0 | 4.8 | 71 | −0.4 | 2.5 | ||
| Female | 69 | 4.1 | 5.9 | .22 | 64 | −0.4 | 4.1 | .27 |
| 0 CAR6-150 | 95 | 4.3 | 5.6 | 96 | −0.4 | 1.8 | ||
| 1-2 CAR | 48 | 2.3 | 4.8 | .04 | 39 | −0.3 | 2.6 | .05 |
| L,L/H FCP6-150 | 130 | 3.4 | 5.5 | 127 | −0.3 | 2.1 | ||
| H/H FCP6-151 | 13 | 4.7 | 5.4 | .43 | 8 | −1.1 | 1.2 | .27 |
| Retic < 300K6-152 | 58 | 1.8 | 3.8 | 59 | 0.0 | 2.1 | ||
| Retic ≥ 300K | 85 | 4.8 | 6.0 | .001 | 77 | −0.7 | 2.0 | .0001 |
| Neuts < 7.5Kρ | 94 | 2.7 | 4.8 | 89 | −0.4 | 2.2 | ||
| Neuts ≥ 7.5K | 49 | 5.3 | 6.3 | .006 | 47 | −0.4 | 1.8 | .01 |
| HbF < 7.5% | 116 | 3.2 | 5.2 | 107 | −0.3 | 1.5 | ||
| HbF ≥ 7.5% | 27 | 5.3 | 6.2 | .07 | 29 | −0.9 | 3.4 | .03 |
| Follow-up | ||||||||
| <80% Adh6-154 | 39 | 2.0 | 5.0 | 42 | −0.3 | 2.0 | ||
| ≥80% Adh | 104 | 4.2 | 5.5 | .03 | 93 | −0.4 | 2.1 | .02 |
| 0-1 toxic6-155 | 41 | 0.6 | 3.8 | 111 | −0.4 | 2.2 | ||
| 2+ toxic | 112 | 4.8 | 5.5 | .0001 | 24 | −0.5 | 1.5 | .0002 |
Mean and SD of the 2-year change in HbF are shown according to cross-classifications of treatment assignment group and the baseline and follow-up characteristics. The mean HbF is tested between the 2 levels of each baseline or follow-up characteristic for the HU and placebo group (P). The interaction (Int) P value tests whether the difference between HU and placebo is the same in both levels of the baseline or follow-up characteristic.
L,L/H, homozygotes, hemizygotes, and heterozygotes for the L or low phenotype.
H/H, homozygotes and hemizygotes for the H or high phenotype.
Reticulocyte count < or ≥300,000/μL.
ρ Neutrophil count < or ≥7,500/μL.
Less than or ≥80% capsule count adherence.
One or no episodes of toxicity or two or more toxic episodes.