Table 2. Erythroid and cytogenetic responses to lenalidomide.
| Response | All patients (N=148) | Patients in follow-up phase (n=54) | Patients not in follow-up phase (n=94) |
|---|---|---|---|
| Erythroid response, n/N (%) | |||
| RBC-TI ⩾8 weeks | 97/148 (65.5) | 46/54 (85.2) | 51/94 (54.3) |
| Minor responsea | 16/148 (10.8) | 6/54 (11.1) | 10/94 (10.6) |
| RBC-TI ⩾8 weeks+minor response | 113/148 (76.4) | 52/54 (96.3) | 61/94 (64.9) |
| RBC-TI ⩾8 weeks by IPSS, n/N (%)b | |||
| Low-risk | 34/49 (69.4) | 15/19 (78.9) | 19/30 (63.3) |
| Intermediate-1-risk | 47/69 (68.1) | 21/23 (91.3) | 26/46 (56.5) |
| Intermediate-2-risk/High-risk | 3/9 (33.3) | 2/3 (66.7) | 1/6 (16.7) |
| Unable to classify | 13/21 (61.9) | 8/9 (88.9) | 5/12 (41.7) |
| RBC-TI ⩾8 weeks by baseline karyotype, n/N (%)c | |||
| Isolated del(5q) | 78/110 (70.9) | 40/47 (85.1) | 38/63 (60.3) |
| del(5q) plus 1 additional abnormality | 12/25 (48.0) | 4/5 (80.0) | 8/20 (40.0) |
| del(5q) plus ⩾2 additional abnormalities | 7/12 (58.3) | 2/2 (100) | 5/10 (50.0) |
| Unable to classifyd | 0/1 (0) | 0/0 (0) | 0/1 (0.0) |
| Median time to RBC-TI ⩾8 weeks, months (95% CI) | 1.3 (1.1–1.5) | 0.8 (0.6–1.3) | 1.9 (1.3–2.5) |
| Cytogenetic response,e n/N (%) | |||
| Complete | 40/88 (45.5) | 20/40 (50.0) | 20/48 (41.7) |
| Partial | 23/88 (26.1) | 12/40 (30.0) | 11/48 (22.9) |
| Complete plus partial | 63/88 (71.6) | 32/40 (80.0) | 31/48 (64.6) |
Abbreviations: CI, confidence interval; del(5q), chromosome 5q deletion; IPSS, International Prognostic Scoring System; RBC-TI, red blood cell-transfusion independence.
a
Minor erythroid response was defined as ⩾50% reduction in the number of transfusions over 8 weeks.
b
P-value for RBC-TI ⩾8 weeks across subgroups was 0.205.
c
P-value for RBC-TI ⩾8 weeks across subgroups was 0.155.
d
del(5q) was confirmed by fluorescence in situ hybridization in one patient with normal metaphase karyotype.
e
Complete cytogenetic response evaluation required ⩾2 abnormal metaphases at baseline and was defined as the absence of abnormal metaphases after treatment. Partial cytogenetic response was defined as ⩾50% reduction in the proportion of abnormal metaphases.