Table 1. Summary of the ABL tyrosine kinase inhibitor stop studies.
| Study | Which TKI, stopped | N | Median age (years) | Imatinib (or dasatinib) at least (years) | Median duration of imatinib (+ dasatinib) (months) | Definition of the enough clinical effects | CMR, UMRD or DMR at least (years) | Median duration of CMR, UMRD or DMR (months) | Definition of molecular relapse | TFR rate at 12M after discontinuation | Ref |
|---|---|---|---|---|---|---|---|---|---|---|---|
| STIM | Imatinib | 100 | 62 | 3 | 50 | CMR; decrease in BCR-ABL mRNA of at least 5 log from baseline and undetectable by RQ-PCR |
2 | 36 [24-85] | Two consecutive BCR-ABL ratio of at least 10−5 in comparison to ABL and RQ-PCR positive results | 41% (at 12 months) | (4) |
| TWISTER | Imatinib | 40 | 61 | 3 | 70 | UMRD; decrease in BCR-ABL mRNA of at least 4.5 log as indicated by RQ-PCR based on the IS |
2 | 36 [24-82] | Loss of at least 0.1% (MMR) according to IS or two consecutive detectable RQ-PCR results | 47% (at 24 months) | (6) |
| A-STIM | Imatinib | 80 | 55 | 3 | 79 | CMR; undetectable BCR-ABL transcript with sensitivity; 40,000 amplified copies of the ABL control gene |
2 | 41 [24-96] | Loss of at least 0.1% (MMR) according to IS | 64% (at 12 & 24 months)* | (7) |
| ISAV | Imatinib | 112 | 49 | 2 | 103 | CMR; undetectable BCR-ABL transcript with sensitivity between MR4 and MR4.5 |
1.5 | 26 [16-99] | Two consecutive positive results using dPCR or MMR loss | 48% (at 24 months) | (8) |
| DADI | Dasatinib (second or third line) | 63 | 59 | 1 (dasatinib) | 62 (+ dasatinib 17) | DMR; decrease in BCR-ABL mRNA of at least 4.16 log as indicated by RQ-PCR based on the IS |
1 | NA | Loss of DMR even at one analysis point | 48% (at 12 months) | (5) |
*, MMR loss. CMR, complete molecular response; UMRD, undetectable minimal residual disease; DMR, deep molecular response; MMR, major molecular response; TFR, treatment free remission; RQ-PCR, real time quantitative-PCR; IS, international scale; MR, molecular response; dPCR, digital PCR; NA, no application.