BCR::ABL1 E255K nilotinib-resistance mutation
Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.
| ID | BIO-BCR-ABL1-E255K |
|---|---|
| Type | Biomarker |
| Aliases | ABL1 p.E255KBCR-ABL E255KBCR-ABL1 E255K resistance mutationBCR::ABL1 E255K — мутація резистентності до нілотинібуP-loop mutation |
| Status | reviewed 2026-04-27 | pending_clinical_signoff |
| Diseases | None declared |
| Sources | SRC-ELN-CML-2020 SRC-ELN-CML-2025 SRC-ESMO-CML-2017 |
Biomarker Facts
| Biomarker type | gene_mutation |
|---|---|
| Mutation details | {"exon": "4", "functional_impact": "partial nilotinib resistance and reduced imatinib sensitivity; dasatinib, bosutinib, ponatinib retain activity", "gene": "ABL1", "hgvs_protein": "p.E255K", "variant_type": "missense"} |
| Measurement | MethodBCR::ABL1 kinase-domain Sanger sequencing OR targeted NGS at TKI failure Unitscategorical (positive | negative); VAF % when NGS |
| Actionability lookup | {"gene": "ABL1", "variant": "E255K"} |
| Related biomarkers | BIO-BCR-ABL1 BIO-BCR-ABL1-T315I BIO-BCR-ABL1-V299L |
Notes
Classical P-loop mutation of ABL1. Reduces nilotinib sensitivity (IC50 ~5-7x baseline) and imatinib sensitivity (IC50 ~10-20x); associated with adverse prognosis on imatinib. Dasatinib, bosutinib, ponatinib retain in-vitro activity. Per ELN-2020 / ELN-2025: detection on nilotinib or imatinib failure → switch to dasatinib (preferred 2G-TKI option) or ponatinib. P-loop mutations as a class (E255K, Y253H, G250E) generally favor dasatinib-based salvage; T315I excluded per separate biomarker.
Used By
Biomarker
BIO-BCR-ABL1-T315I- BCR::ABL1 T315I gatekeeper mutation