Gabriel Etienne

PURPOSE: Treatment-free remission (TFR) is a major therapeutic objective in chronic myeloid leukemia (CML). However, nearly 50% of patients relapse after tyrosine kinase inhibitor (TKI) discontinuation, and no robust predictive biomarker is currently available. METHODS: We profiled peripheral blood cell transcriptomes at imatinib (IMA) discontinuation in patients from the multicenter STIM2 trial (n = 96) to develop a transcriptome-based model predicting TFR by 2 years. A DESEQ2-based machine learning approach was compared with classical machine learning algorithms. The signature was then externally validated in an independent real-world cohort of patients attempting IMA or nilotinib cessation (n = 70). The biologic processes associated with the signature were further explored. RESULTS: We identified a 50-gene signature discriminating patients with sustained 2-year TFR from those experiencing molecular relapse (area under the receiver operating characteristic curve [AUROC], 0.83 [95% CI, 0.73 to 0.93] and 0.75 [95% CI, 0.55 to 1.00] in the training and internal validation cohorts, respectively). The discriminative performance was confirmed in the external test cohort, both as a binary predictor of 2-year TFR (AUROC, 0.71 [95% CI, 0.58 to 0.83] overall; 0.77 [95% CI, 0.61 to 0.92] in IMA-treated patients) and as a time-to-event predictor (log-rank P = .0042). The high TFR-signature group showed a higher proportion of myeloid immune cells and natural killer T cells, with an enrichment in Hedgehog signaling, whereas the low TFR-signature group demonstrated a higher proportion of lymphoid cells with an enrichment in mTOR signaling and a trend for oxidative phosphorylation activation. T-cell receptor and immunoglobulin heavy-chain repertoire analyses showed significantly greater polyclonality in the high TFR-signature group. CONCLUSION: These findings demonstrate that transcriptomic profiling at TKI discontinuation can predict TFR outcomes in patients with CML and provide biologic insights into the mechanisms underlying sustained TFR.

Myeloid/lymphoid neoplasms with tyrosine kinase rearrangements (MLN-TKs) are rare clonal eosinophilias driven by PDGFRA, PDGFRB and other kinase fusions, highly sensitive to tyrosine kinase inhibitors. Their detection remains challenging, particularly for cryptic PDGFRA rearrangements. We performed a large multicenter real-world validation of the generic quantitative RT-PCR assay (gPDGFR), which detects 3′ PDGFRA/PDGFRB overexpression independently of fusion partner. A total of 231 consecutive patients with hypereosinophilia from 12 French centers were analyzed, and assay robustness was further assessed in an independent heterogeneous cohort of 102 tyrosine kinase inhibitor (TKI)-treated patients. Twenty-two PDGFR-rearranged cases (14 PDGFRA-r, 8 PDGFRB-r) were identified. The assay demonstrated 100% sensitivity and 100% negative predictive value. For PDGFRA, positive predictive value and specificity reached 100%. In contrast, PDGFRB overexpression showed lower specificity due to borderline false-positive cases, underscoring the need for confirmatory testing. In selected patients, longitudinal gPDGFR kinetics paralleled fusion-specific RT-qPCR, supporting its use for molecular follow-up when dedicated assays are unavailable, although it does not provide quantitative measurable residual disease assessment. Overall, gPDGFR represents a robust, partner-independent first-line screening strategy that can be readily integrated into routine diagnostic workflows to enable timely identification of patients eligible for targeted therapy.

Many patients receiving frontline tyrosine kinase inhibitors (TKIs) for chronic-phase chronic myeloid leukemia (CML-CP) experience inadequate disease control and/or adverse events (AEs) that impair quality of life. Treatments offering optimal efficacy, safety, and tolerability will support long-term therapy. In the primary analysis from the ASC4FIRST trial, a phase 3 randomized trial comparing asciminib with investigator-selected TKIs (IS-TKIs) in newly diagnosed CML-CP, asciminib demonstrated superior efficacy vs all IS-TKIs and vs imatinib in the imatinib stratum, meeting both primary objectives. In the secondary analysis (2.2 years' median follow-up), major molecular response (MMR) rate at week 96 was 74.1% with asciminib vs 52.0% with IS-TKIs (treatment difference, 22.4% [95% confidence interval (CI), 13.6-31.3]; 1-sided P< .001) and 76.2% with asciminib vs 47.1% with imatinib in the imatinib stratum (treatment difference, 29.7% [95% CI, 17.6-41.8]; 1-sided P< .001), meeting both key secondary objectives. MMR rate was 72.0% with asciminib vs 56.9% with second-generation (2G) TKIs (treatment difference, 15.1% [95% CI, 2.3-28.0]; 1-sided P< .05), suggesting possible clinical benefit, although the study was not designed to formally confirm statistical significance for this secondary end point. Safety/tolerability remained favorable with asciminib vs IS-TKIs. Dose reductions and interruptions, respectively, occurred with asciminib (18.5%; 46.5%), imatinib (23.2%; 47.5%), and 2G TKIs (54.9%; 63.7%). The hazard ratio for time to discontinuation of treatment due to AEs for asciminib vs 2G TKIs was 0.46 (95% CI, 0.215-0.997). With longer follow-up, asciminib continued to demonstrate a favorable benefit-risk profile over IS-TKIs and imatinib, supporting its potential as a treatment option for newly diagnosed CML-CP. This trial was registered at www.clinicaltrials.gov as NCT04971226.

Myeloid/lymphoid neoplasms with tyrosine kinase rearrangements (MLN-TK) are rare clonal eosinophilias driven by PDGFRA, PDGFRB and other kinase fusions, highly sensitive to tyrosine kinase inhibitors. Their detection remains challenging, particularly for cryptic PDGFRA rearrangements. We performed a large multicenter real-world validation of the generic quantitative RT-PCR assay (gPDGFR), which detects 3′ PDGFRA/PDGFRB overexpression independently of fusion partner. A total of 231 consecutive patients with hypereosinophilia from 12 French centers were analyzed, and assay robustness was further assessed in an independent heterogeneous cohort of 102 TKI-treated patients. Twenty-two PDGFR-rearranged cases (14 PDGFRA-r, 8 PDGFRB-r) were identified. The assay demonstrated 100% sensitivity and 100% negative predictive value. For PDGFRA, positive predictive value and specificity reached 100%. In contrast, PDGFRB overexpression showed lower specificity due to borderline false-positive cases, underscoring the need for confirmatory testing. In selected patients, longitudinal gPDGFR kinetics paralleled fusion-specific RT-qPCR, supporting its use for molecular follow-up when dedicated assays are unavailable, although it does not provide quantitative measurable residual disease assessment. Overall, gPDGFR represents a robust, partner-independent first-line screening strategy that can be readily integrated into routine diagnostic workflows to enable timely identification of patients eligible for targeted therapy.

Commutation plot visualizing the mutated genes in t-MN after OC according to PARPi treatment.

TP53 mutations characteristics among t-MN PARPi national cohort.

Flow chart of the study displaying the three cohorts.

Waffle chart (%) of patients addressed for cytopenia exploration after OC exposed to a PARPi treatment from cytopenia diagnosis (A) and cytopenia diagnosis based on NGS results (B). Dot plots (C) showing the median WBC, hemoglobin, and platelet counts from patients referred for cytopenia exploration after OC exposed to a PARPi treatment according to t-MN diagnosis (“t-MN”) or not (“Cytopenia”).

Blood smear and bone marrow aspiration of patient referred for cytopenia post PARPi.

Patient characteristics of the national cohort according to the type of PARPi received (olaparib vs. other PARP inhibitors).