ABL1 fusion

No significant differences in genetic profiles, treatment response, or outcomes were observed between patients with and without CML-like features. This study provides a comprehensive genomic and clinical characterization of BCR::ABL1-positive MPAL, supporting improved risk stratification and future therapeutic strategies.

Imatinib, the first TKI, demonstrated unprecedented hematologic, cytogenetic, and molecular responses, rapidly becoming the standard of care in CML...Despite these achievements, important challenges remain, including TKI resistance, safety considerations, and the relatively low proportion of patients who achieve and maintain TFR. Newer-generation TKIs, combination strategies, immunomodulatory approaches, and emerging treatment modalities such as degraders offer promising avenues to further improve outcomes, expand TFR eligibility, ensure optimal quality of life, address resistance mechanisms, and render therapy available and affordable to all patients with CML worldwide.

The case also contributes to the limited literature reporting systemic CMV infections associated with dasatinib. In addition, it extends the spectrum of reported dasatinib-associated infections to include Granulicatella adiacens.

The splicing variations mainly occur in ABL1 exon 3 or different exons of BCR, and some are accompanied by intron sequence insertions. Patients with e13a3 type of rare transcripts respond well to TKI treatment, while patients with the e1a3 and e19a2 have poor prognosis.

BCR::ABL1 e6a3 demonstrated enhanced sensitivity to active-state selective inhibitors dasatinib and bosutinib, whereas BCR::ABL1 e6a3/T315I remained resistant. These data show that treatment with asciminib and ponatinib can select for mutations with notably elevated enzymatic activity, effectively targeted by an axitinib-based triple combination. These data highlight the remarkable mutability of the BCR::ABL1 kinase, including through novel isoforms and provides a strong rationale for the clinical assessment of a triple inhibitor combination as a strategy to overcome resistance to dual ponatinib and asciminib therapy.

By comparison, mechanistic learning achieves comparable or improved combination scores for BCR::ABL1-positive and MRD-positive disease, with scores of 0.81 and 0.71, respectively, using only de-differentiation for BCR::ABL1 and primitive-state persistence together with differentiation-directed exit for MRD. Thus, the mechanistic-learning approach not only preserves predictive performance, but also provides a biological hypothesis for why stemness is predictive of these clinically relevant outcomes.

This led to development of tyrosine kinase inhibitors (TKIs) such as Imatinib, Nilotinib, and Ponatinib. Asciminib does not appear to induce a prothrombotic or proinflammatory state under the conditions studied, which may be advantageous for CML patients. However, the observed increase in thrombin generation over time suggests a potential effect on secondary haemostasis that warrants further investigation in controlled studies.

It also focuses on bypass pathways, the B-cell/CLL lymphoma 2 family, tumor suppressor genes, microRNAs, and molecular chaperones as independent resistance mechanisms. Furthermore, the potential for combination therapies targeting these resistance mechanisms is discussed, anticipating further advances in research aimed at overcoming TKI resistance in CML.

The patient achieved molecular remission following chemotherapy with the Hyper-CVAD/MA regimen combined with a tyrosine kinase inhibitor (TKI). This case underscores the importance of differentiating BP-CML among adult Ph-positive T-lymphoblastic neoplasms and highlights the value of multi-platform integrated diagnosis for identifying atypical presentations.

One case exhibited an atypical FISH pattern consistent with a cryptic microinsertion. These findings indicate that masked-Ph ALL is relatively common and may be overlooked without molecular testing, underscoring the importance of incorporating RT-PCR and FISH at diagnosis.