Chronic myeloid leukemia molecular responses defined
| Response . | Definition . |
|---|---|
| Early molecular response | BCR-ABL1 ≤10% (PB) |
| BCR-ABL1 < 1% | Molecular equivalent of CCyR |
| Major molecular response | BCR-ABL1 ≤0.1% (PB) (common trial endpoint) |
| Deeper molecular responses (MR) | BCR-ABL1 ≤0.01% (MR 4) (PB) |
| BCR-ABL1 ≤0.0032% (MR 4.5) (PB) | |
| Or undetectable BCR-ABL1 with specific detection of control gene* |
| Response . | Definition . |
|---|---|
| Early molecular response | BCR-ABL1 ≤10% (PB) |
| BCR-ABL1 < 1% | Molecular equivalent of CCyR |
| Major molecular response | BCR-ABL1 ≤0.1% (PB) (common trial endpoint) |
| Deeper molecular responses (MR) | BCR-ABL1 ≤0.01% (MR 4) (PB) |
| BCR-ABL1 ≤0.0032% (MR 4.5) (PB) | |
| Or undetectable BCR-ABL1 with specific detection of control gene* |
CCyR, complete cytogenetic response (no Philadelphia chromosome–positive metaphases by bone marrow examination); PB, peripheral blood.
Control genes include ABL, BCR, and GUSB. For example, specific control gene detection for MR4 requires a minimum of 10 000 ABL1 transcripts or 24 000 GUSB transcripts, and for MR4.5, it requires a minimum of 32 000 ABL1 transcripts or 77 000 GUSB transcripts.