Rates of CCyR and MMR at 12 months and PFS at 36 and 48 months, according to the molecular response at 3 months, in 40 children with CML
| BCR-ABL1/ABL transcript level at 3 mo* . | Molecular response rate outcome over 12 mo** . | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| BCR-ABL1/ABL at 3 mo, % . | n (%) . | CCyR at 12 mo (%) . | MMR at 12 mo (%) . | PFS at 36 mo (%) . | PFS at 48 mo (%) . | BCR-ABL1/ABL level* . | n (%) . | No. of patients achieving MMR at 12 mo (%) . | |
| at 3 mo, % . | at 6 mo, % . | ||||||||
| ≤10 | 25 (63) | 19*** (76) | 12 (48) | 100 | 100 | >10 | >10 | 4 (10) | 0 |
| >10 | 15 (37) | 7 (47) | 1 (7) | 92 | 61 | >10 | <10 | 11 (27.5) | 1 |
| (95% CI, 54-99) | (95% CI, 7-91) | <10 | >10 | 1 (2.5) | 1 | ||||
| P = .177 | P = .0128 | P = .028 (overall) | <10 | <10 | 24 (60) | 11 | |||
| BCR-ABL1/ABL transcript level at 3 mo* . | Molecular response rate outcome over 12 mo** . | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| BCR-ABL1/ABL at 3 mo, % . | n (%) . | CCyR at 12 mo (%) . | MMR at 12 mo (%) . | PFS at 36 mo (%) . | PFS at 48 mo (%) . | BCR-ABL1/ABL level* . | n (%) . | No. of patients achieving MMR at 12 mo (%) . | |
| at 3 mo, % . | at 6 mo, % . | ||||||||
| ≤10 | 25 (63) | 19*** (76) | 12 (48) | 100 | 100 | >10 | >10 | 4 (10) | 0 |
| >10 | 15 (37) | 7 (47) | 1 (7) | 92 | 61 | >10 | <10 | 11 (27.5) | 1 |
| (95% CI, 54-99) | (95% CI, 7-91) | <10 | >10 | 1 (2.5) | 1 | ||||
| P = .177 | P = .0128 | P = .028 (overall) | <10 | <10 | 24 (60) | 11 | |||
mo, months.
Data from 15 highly standardized French laboratories (ie, following tightly standardized procedures, having at their disposal a conversion factor and participating in the French external quality assessment program organized by the Group of Molecular Biologists for Malignant Hemopathies which requires biannual evaluation of interlaboratory reproducibility and accuracy) were collected and centrally reviewed for updating molecular response level attribution according to the latest recommendations of the ELN.12
This portion of the table shows that achieving a <10% cutoff ratio at 3 mo is in favor of a higher rate of MMR at 12 mo. However, it is also documented that a delayed cutoff ratio achievement of this <10% cutoff ratio at 6 mo with favorable outcome may exist. The small sample size of children does not allow providing robust rate estimates within subgroups.
One patient with no conventional cytogenetic assessment at 12 mo achieved MR4.5 at this time point and was considered as having a CCyR.