The primary analysis of the phase 2 OPTIC trial (NCT02467270) demonstrated optimal benefit:risk with response-based ponatinib dosing (45 mg once daily (QD) reduced to 15 mg QD) upon achieving ≤1% BCR::ABL1IS in patients with tyrosine kinase inhibitor-resistant or T315I-positive chronic-phase chronic myeloid leukemia (CP-CML). Here, we report 5-year long-term outcomes. Overall, 283 patients were randomized to 45-mg, 30-mg, or 15-mg QD starting doses (n = 94, 95, and 94, respectively), with dose reduction to 15 mg QD upon response in the 45-mg and 30-mg cohorts. At data cutoff, 61 patients remained on trial. Median follow-up time was 75-78 months. By 5 years, 60%, 41%, and 40% of patients in the 45-mg, 30-mg, and 15-mg cohorts, respectively, achieved ≤1% BCR::ABL1IS. Five-year progression-free survival rates were 63%, 57%, and 60%, respectively, by cohort; overall survival rates exceeded 80%. In patients with a T315I mutation, 5-year rates of ≤1% BCR::ABL1IS, PFS, and OS were highest in the 45-mg cohort. Exposure-adjusted rates of adjudicated arterial occlusive events were 4.1, 3.8, and 2.0 patients per 100 patient-years, respectively, by cohort; results were comparable in T315I-positive patients. These findings support long-term clinical benefit of response-based ponatinib dosing in third-line CP-CML, especially in patients with the T315I mutation.

BACKGROUND:Second generation tyrosine kinase inhibitors (TKIs) have improved response rates in patients with chronic phase chronic myeloid leukaemia (CP-CML). Phase 2 trials demonstrated increased deep molecular response rates when combining second generation TKIs with pegylated interferon alfa (Peg-IFN). This trial aimed to evaluate the efficacy and the safety of combining nilotinib with Peg-IFN alfa-2a in patients with newly diagnosed CP-CML. METHODS:In PETALs, this open-label, randomised, multicentre phase 3 trial, we enrolled patients with newly diagnosed CP-CML from 27 French academic institutions via a centrally-generated electronic system in a 1:1 ratio to two groups: 300 mg oral nilotinib alone twice a day (the nilotinib only group) or 300 mg nilotinib twice a day combined with subcutaneous Peg-IFN (30 μg per week for the first month of treatment and 45 μg per week thereafter) for a maximum of 2 years. The randomly allocated patients were stratified by their Sokal index and European Treatment and Outcome Study long-term survival index. Eligible patients had major BCR::ABL1 transcripts, an Eastern Cooperative Oncology Group performance score of two or lower, who had never received TKIs, and were aged between 18 and 65 years. The primary endpoint was the cumulative rate of molecular response 4·5 (MR4·5; defined as BCR::ABL1 international scale [IS] of 0·0032% and lower), analysed in the intention-to-treat population (n=200). This trial is registered at ClinicalTrials.gov, NCT02201459, and is completed. FINDINGS:205 patients were enrolled between Aug 6, 2014, and Sept 29, 2016, after which five patients were declared ineligible and excluded, resulting in 200 patients being randomly allocated (99 to the nilotinib group and 101 to the combination group). The median age at diagnosis was 45 years (IQR 36-55); 130 patients (65%) were male and 70 (35%) were female. Median follow-up in this cohort was 67 months (IQR 32·6-70·6). The primary objective was met, with higher rates of MR4·5 in the combination group (24% [95% CI 16·0-34·1] vs 15% [8·6-24·2], p=0·048) at month 12. There were equivalent grade 3-4 haematological side effects in the both groups (14 vs 14) with a predominance for grade 3-4 thrombocytopenia without haemorrhages (six in the combination group vs five in the nilotinib group). Psychiatric grade 3-4 events occurred in six (6%) patients in the combination group (including three unsuccessful suicide attempts) compared with five (5%) in the nilotinib group (including one unsuccessful suicide attempt). Six vascular events also occurred in six patients in the combination group and seven vascular events in five patients in the nilotinib group (all grades 3-4). INTERPRETATION:In this setting, Peg-IFN combined with nilotinib induced higher initial rates of MR4·5 compared to TKI monotherapy, despite additional side effects. The onset of psychiatric events might promote immediate cease of Peg-IFN and psychiatrist advice Whether this early molecular response translates into sustained treatment-free survival should be studied in a randomised trial sufficiently powered for this outcome. FUNDING:Novartis Pharma.

6526 Background: ATP-competitive tyrosine kinase inhibitors (TKIs) in combination with chemoimmunotherapy have improved outcomes in Ph+ ALL; still, some pts relapse despite appropriate frontline therapy and have limited options. ASC is approved for Ph+ chronic myeloid leukemia in chronic phase. The ASC managed access program (MAP) allowed adults with Ph+ ALL refractory/resistant or intolerant to available treatment (Tx) to receive ASC as monotherapy or combination under individual request when the potential benefit outweighed the risk. Methods: This was a non-interventional, multi-country, retrospective chart review in eligible pts with Ph+ ALL aged ≥18 who were refractory/resistant or intolerant to available Tx and who received ≥1 dose of ASC within the MAP. Index date (date of first ASC administration) occurred between 1 March 2019 and 30 June 2023. Existing data were extracted from index date up to 13 months (mo), or until discontinuation, death or last visit, whichever occurred first. The primary endpoint was complete hematologic remission (CR) and CR with incomplete count recovery (CRi) anytime in the first 3 mo of Tx based on peripheral blood assessments. Results: A total of 37 pts were enrolled. At Tx start, 25 pts (67.6%) received ASC as monotherapy. Median ASC dose intensity was 400 mg/day (range 71.6–400.0). Overall, 23 pts (62.2%) achieved CR/CRi within 3 months (95% CI: 44.8, 77.5). Median duration of response was 7.4 mo. Median overall survival was 7.7 mo. Nineteen pts were assessed for minimal residual disease (MRD) at time of CR/CRi and 7 (36.8%) were MRD-. Of the 13 pts with T315I mutation, 10 achieved CR or CRi at any time during follow-up. Thirty-three pts (89.2%) permanently discontinued ASC; reasons for permanent discontinuation included disease progression (n=16) and adverse events (AEs, n=5). Any-grade Tx-emergent AEs were reported in 73.0% (Grade ≥3, 56.8%) of pts; the most common any-grade AE was neutropenia (21.6%). No new safety signals were observed. Most deaths (22/28) were Ph+ ALL related. Conclusions: Adults with Ph+ ALL that was relapsed, resistant/refractory or intolerant to previous Tx achieved high rates of CR/CRi with ASC as monotherapy or in combination with chemotherapy/immunotherapy, despite most pts being heavily pretreated and/or harboring poor prognosis markers (Table). The safety profile was consistent with previous studies. Results, while positive, should be cautiously interpreted given the retrospective nature of the study and heterogenous population. Pt baseline characteristics. Pts N=37 Median age (range), years 53 (19─84) Disease status (bone marrow blasts), %≥5%<5%Unknown 67.624.38.1 Prior treatment lines, %123≥4 2.732.421.643.2 Ponatinib pretreatment, % 94.6 T315I mutation, % 35.1 Reason for starting ASC, %RelapseSpecific mutationsResistanceIntoleranceOther 67.627.024.318.913.5

ABSTRACT:The Group for Research in Adult Acute Lymphoblastic Leukemia (GRAALL)-2014 trial evaluated an intensive, age-adapted protocol for adults aged 18 to 59 years with Philadelphia chromosome negative acute lymphoblastic leukemia. The trial was motivated by findings from the previous GRAALL-2005 study, which reported excessive toxicity from pediatric-inspired therapy in older patients and no added benefit from allogeneic hematopoietic stem cell transplantation (allo-HSCT) among those with an early favorable response to treatment. Thus, the GRAALL-2014 protocol aimed to reduce treatment-related toxicity in patients aged ≥45 years and to limit allo-HSCT to patients with poor measurable residual disease (MRD) responses. A total of 743 patients were included, and outcomes were compared with those of GRAALL-2005 trial. The GRAALL-2014 study demonstrated reduced early mortality and higher complete remission rates in patients aged ≥45 years. MRD-guided transplantation decisions reduced allo-HSCT indications by ∼50%. Although older patients experienced a higher cumulative incidence of relapse, no significant difference in disease-free survival (DFS) was observed compared with historical cohorts across age subgroups. The overall 4-year DFS was 57.1% (95% confidence interval [CI], 53.4-61.1). Notably, 4-year overall survival improved significantly, from 65.5% (95% CI, 61.7-69.8) to 71.7% (95% CI, 67.7-76.0) in younger patients (P = .031) and from 49.6% (95% CI, 43.5-56.5) to 59.5% (95% CI, 53.5-66.3) in older patients (P = .011). These findings highlight the value of individualized treatment strategies that balance efficacy and safety. Future studies should investigate the integration of immunotherapy to further reduce treatment intensity and improve outcomes. This trial was registered at www.clinicaltrials.gov as #NCT02617004 and #NCT02619630.

Background : Hydroxyurea (HU) is sometimes used before confirmation of the diagnosis of chronic-phase chronic myeloid leukemia (CP-CML) and treatment with tyrosine kinase inhibitors (TKI). The limited literature data suggest that this strategy does not offer any benefit, but no large-scale study has been conducted on this subject. Methods: From the French CML Observatory (a French registry with real-world data on patients with CP-CML), we identified patients treated with HU before TKI initiation (pre-TKI HU; n=370) and patients treated directly with TKI (direct TKI n=430). First, we compared the frequency of side effects in the two groups. Then, to take into account some factors that could confound the therapeutic response, particularly leukocytosis, we selected patients for whom we had data on baseline leukocytosis and calculated a propensity score to balance the pre-TKI HU and direct TKI groups. Then, we compared the cumulative incidence rates of the different molecular response (MR) levels, mean TKI doses, number of treatment-free days in the first year, and cumulative incidence of first switch in the two weighted patient groups. Results : Overall, prescribing HU for a short period (median: 16 days) increased the frequency of edema in patients treated with imatinib (23% in the pre-TKI HU vs. 15% in the direct TKI group; p=0.026) and of hematological toxicity when taking second-generation TKIs (19% vs. 5.5%; p<0.001). Moreover, the likelihood of achieving a deep molecular response was reduced in the pre-TKI HU group, as indicated by the different cumulative incidences of MR4 and MR4.5 between groups and the lower rates of MR4.5in the pre-TKI HU group over time (HR = 0.66 [0.48-0.90]; p=0.008). This effect was observed in both the imatinib and second-generation TKI subgroups. Conversely, the TKI dose, number of days of treatment during the first year, and cumulative incidence of first switch were similar in the pre-TKI HU and direct TKI groups. Conclusions: Based on these results, we propose to restrict and shorten HU administration before TKI initiation to the minority of patients with suspected leukostasis or symptomatic splenomegaly and to prioritize earlier TKI initiation.

Abstract B‐cell acute lymphoblastic leukemia (B‐ALL) is a heterogeneous malignancy driven by diverse genetic alterations. Among these, CEBP family genes and ZEB2 are recurrently involved, yet the spectrum of genomic mechanisms and their clinical impact remain incompletely defined. Integrated genomic analyses of a cohort of 992 Philadelphia‐negative adult B‐ALL patients revealed multiple mechanisms of enhancer hijacking‐mediated deregulation of CEBPA, CEBPB, CEBPD, and CEBPE, including IGH and several non‐IGH fusions, as well as noncoding mutations in regulatory regions. Combined with gene expression analysis, we identified three distinct subtypes, defined by co‐occurring CEBP and ZEB2 p.H1038R alterations (CEBP/ZEB2, n = 18 cases); isolated CEBP alterations (CEBPalt, n = 43), associated with frequent IKZF1 deletions and FLT3 deregulation; and isolated ZEB2 p.H1038R mutation (ZEB2alt, n = 15), associated with various additional genomic hits targeting ZEB2 and enhancing mutant ZEB2 expression. The three subtypes exhibited distinct clinical features, including age distribution (patients with CEBP/ZEB2 and ZEB2alt B‐ALL were younger) and sex bias (female and male predominance in CEBPalt and ZEB2alt, respectively). Early treatment responses and outcomes also differed: patients with CEBP/ZEB2 B‐ALL had a favorable early response, in contrast to patients with ZEB2alt B‐ALL, who had high levels of minimal residual disease and a dismal prognosis. Collectively, our findings define CEBP and ZEB2 alterations as drivers of genetically and clinically distinct subtypes of adult B‐ALL and provide a rationale for subtype‐specific risk stratification. Preclinical experiments in CEBPalt B‐ALL patient‐derived xenografts demonstrated sensitivity to FLT3 inhibition, highlighting a potential therapeutic vulnerability.

Tyrosine kinase inhibitors of the BCR::ABL1 oncoprotein can be stopped without subsequent molecular relapse or major safety concerns in 40-80 % of adult patients with P210BCR::ABL1 positive chronic myeloid leukemia with sustained deep molecular responses. In contrast, ending treatment in patients with rare rearrangements located outside the major BCR region or within the exon 3 of ABL1 remains to be explored. Twenty-four patients with chronic phase disease and diverse uncommon BCR::ABL1 transcripts who obtained sustained molecular residual disease negativity and stopped therapy in a real-life setting for various reasons were retrospectively evaluated for treatment-free remission determinants. Six patients relapsed after a median time of 6 months (range; 3-49), relapse being defined as a rise in molecular residual disease above the 3-log threshold. Treatment-free remission probabilities at 12 and 60 months were 83.3 % (95 % CI: 68.4-98.2 %) and 70.6 % (95 % CI: 49.5-91.6), respectively. The type of BCR::ABL1 transcript was the only relevant baseline factor associated with durable treatment-free remission and patients with fusions lacking exon a2 sequences had the best outcome. To conclude, treatment-free remission is a reasonably achievable goal in patients with rare ABL1 fusion transcripts. Our results pave the way for recommendations in clinical practice. Nevertheless, further research is needed to determine which patients have highest chances to reach deep molecular response levels and become free from therapy and to decipher the biological impact of the different molecular rearrangements of BCR::ABL1 on treatment-free remission.

ABSTRACT:T-cell acute lymphoblastic leukemia (T-ALL) represents a group of aggressive hematological malignancies characterized by unfavorable prognosis, urging the need for innovative therapeutic strategies. LEF1 is a member of the lymphoid enhancer factor (LEF)/T-cell factor family of DNA-binding transcription factors, known for their interaction with nuclear β-catenin in the context of the Wnt signaling pathway. Although the implication of LEF1 in colon cancer is well documented, its clinical relevance and functional consequences remain elusive in T-ALL. In this study, we provide valuable insights into the prevalence and significance of LEF1 alterations in a comprehensive cohort of 474 pediatric and adult patients with T-ALL enrolled in the FRALLE-2000 (French group for childhood ALL) and GRAALL 2003-2005 (Group for Research on Adult Acute Lymphoblastic Leukemia) trials, respectively. LEF1 alterations were detected in 63 cases (13%), including 9 point mutations (14.3%), 18 large deletions (28.6%), and, strikingly, 36 focal deletions (57.1%), which emerge as the most recurrent subtype. LEF1-altered cases were associated with increased central nervous system involvement and improved initial treatment response. Importantly, we unveil the existence of a previously undescribed dominant-negative LEF1 isoform resulting from focal deletions of the exons 2-3. This novel truncated protein, previously unreported in the literature, is associated with the disruption of the Wnt pathway and T-cell receptor signaling, which can be exploited as a therapeutic strategy to enhance chemosensitivity in LEF1-deleted T-ALL cases. The trials were registered at www.clinicaltrials.gov as #NCT00222027 (GRAALL 2003) and #NCT00327678 (GRAALL 2005); FRALLE2000T protocol (FRALLE-2000).

With the advent of immunotherapy, the prognosis of older patients with Philadelphia-negative (Ph-neg) B-cell acute lymphoblastic leukemia (B-ALL) has significantly improved these recent years. Overall survival (OS) is now around 50% at 2 years, with the consequence that is it now possible to consider the outcome of relapsing patients (pts) after a first-line therapy. Here we studied the outcome of pts who relapsed after receiving a frontline immuno-chemotherapy with inotuzumab ozogamicin (InO), an anti-CD22 antibody conjugated to calicheamicin, as part of the EWALL-INO study (NCT03249870, JCO 2024). The RELAPSINO study aimed to retrospectively describe post-relapse outcome in pts included in the single arm phase 2 prospective multicenterEWALL-INO study. In this former study, InO was associated with low dose chemotherapy for 2 induction cycles. In case of complete response (CR), pts then received 6 consolidation cycles and an 18-month (m) POMP maintenance or an allogeneic stem cell transplantation (allo-SCT). At diagnosis, all pts were aged ≥ 55 years and had a newly diagnosed CD22+ Ph-neg B-ALL. A total of 131 pts were included between December, 2017, and March, 2022, and 49 relapses (incidence 38% at 2 years) were documented at last follow-up in May, 2023, including 45 in France, 2 in Finland and 2 in Czech Republic. The RELAPSINO study was approved by the Groupe Nantais d'Ethique dans le domaine de la Santé (GNEDS, reference 24-79-07-100, July 2024). For administrative reason, only French pts were included in this new study. Data regarding pts were updated until May, 2025, and analyses were performed in June, 2025. Since the last follow-up, 6 additional relapses have been documented among French pts. Among the 45 previous relapsed French pts, we excluded 3 pts who presented concomitant therapy-related myelodysplastic syndrome. In total, 48 French relapsed pts (male n=25, female n=23) were included in this updated analysis, of whom 60% had a high-risk cytogenetics at diagnosis. None had received an allo-SCT in CR1. At relapse, median age was 70 years (IQR, 67-74; range, 55-86) and median duration of CR1 was 15.2m (IQR 5.3-22.9). Site of relapse was bone marrow (BM) in 38 (79%) pts, extra-medullary in 4 pts (CNS n=2, testis n=1, vertebra bone n=1) and combined in 3 pts (BM + skin n=1, BM + ocular n=1, BM + CNS n=1) (missing n=3). Although none of the patients received the CD19-CD3 bi-specific T-cell engager blinatumomab before relapse, CD19 and CD22 expressions were negative at relapse in 5/41 (12%) and 9/40 (23%) of evaluable pts, respectively. A large majority of pts were re-treated (n=41, 85%) and 29/41 (71%) received blinatumomab as salvage regimen, either alone (n=14) or after low-dose (n=9) or intensive (n=6) chemotherapy. Twelve pts received chemotherapy only (low dose n=3, intensive n=9). No patient was re-treated with InO or received CAR-T cells as salvage regimen. Half of the pts (n=20/41, 49%) achieved CR2. One was consolidated with CAR-T cells and 4 with an allo-SCT. By multivariate analysis (MA), a CR1 duration > 12m (but not >15m or 18m) was the only significant factor associated with CR2 achievement (p=0.04). With a median follow-up from relapse of 30.3 months (95%CI, 25.0–NA), median event-free survival (EFS) and OS were 3.2m (95%CI 2.3-5.7) and 4.5m (95%CI 3.8-11.0), respectively. Two-year EFS and OS were respectively 15% and 19%. By MA, salvage regimen with intensive chemotherapy (p=0.01), CR1 duration >18m (but not >12m or 15m) (p=0.04), and CR2 (p<0.001) were significantly associated with better OS. Intensive chemotherapy (p=0.008) and CR1 duration >18m (but not >12m or >15m) (p=0.01) were also associated with significant better EFS. The 2-year cumulative incidence of relapse after CR2 was 53%. No predictive factor for second relapse was identified. Median LFS and OS after CR2 were 13m and 24m, respectively, with 2-year LFS and OS of 36% and 46%. In pts who did not achieve CR2, median OS was 3.8m only. Overall, 38 pts (79%) died, the main cause of death being relapse or progression (n=36, 95%). Two pts died in CR2 of unknown cause.Conclusion: Half of older Ph-neg B-ALL patients relapsing after a front-line Ino-based therapy can achieve a new remission and good survival. These encouraging results support the risk of re-treating patients, especially those with late relapse, even with intensive chemotherapy, which appears the best salvage regimen in this series.

Introduction: Ponatinib is a third-generation BCR::ABL1 tyrosine kinase inhibitor (TKI) that potently inhibits native and mutant forms of BCR::ABL1, including T315I. The phase 2 OPTIC (NCT02467270) study evaluated a response-based ponatinib dosing strategy to optimize efficacy and improve safety of ponatinib in patients (pts) with chronic-phase chronic myeloid leukemia (CP-CML) whose disease was resistant to ≥2 TKIs or who had the T315I mutation. The 45-mg once-daily (QD) starting dose with dose reduction to 15 mg QD upon achievement of BCR::ABL1IS ≤1% (MR2) was associated with optimal benefit:risk outcomes, resulting in FDA approval of this response-based dosing strategy for the treatment of pts with CP-CML with disease resistant to ≥2 TKIs or with T315I. We present results from the 5-year update of efficacy and safety outcomes from OPTIC. Methods: Pts with CP-CML resistant to ≥2 TKIs or with the T315I mutation were randomized to ponatinib starting doses of 45 mg, 30 mg, and 15 mg QD. Upon achievement of ≤1% BCR::ABL1IS, doses were reduced to 15 mg in the 45-mg and 30-mg cohorts. The primary endpoint was ≤1% BCR::ABL1IS at 12 months; secondary endpoints included molecular response rates and safety outcomes, including arterial occlusive events (AOEs) adjudicated prospectively by an independent review committee. Progression-free survival (PFS) and overall survival (OS) were analyzed by Kaplan-Meier methods. Exploratory mutational analyses were conducted with baseline and end-of-treatment (EOT) blood samples. Results: A total of 283 pts were randomized (45 mg/30 mg/15 mg: n=94/95/94; median age, 48 years [range: 18‒81 years]; male, 50%; race: White 79%, Asian 15%, Black 2%; ethnicity: 74% not Hispanic or Latino; T315I mutation, 24%). Median dose intensity was 27.7, 23.5, and 14.7 mg/day in the 45-mg, 30-mg, and 15-mg cohorts, respectively. As of the data cutoff (May 2, 2024), when the last pt still on study reached at least 5 years of treatment, 73 pts (26%) remained on ponatinib treatment; the most common reasons for treatment discontinuation were adverse event (45 mg/30 mg/15 mg: n=20/19/17), lack of efficacy (n=16/22/28), and progressive disease (n=8/10/7). By 60 months, 60% (56/93), 41% (38/93), and 40% (36/91) of pts in the 45-mg, 30-mg, and 15-mg cohorts, respectively, achieved ≤1% BCR::ABL1IS. Pts with a T315I mutation at baseline also had a higher MR2 rate by 60 months at the 45-mg starting dose (64%; n=25), which was comparable to those with no mutations at baseline (60%; n=50). Median duration of ≤1% BCR::ABL1IS was not reached in any cohort. By 60 months, the rates of ≤0.01% BCR::ABL1IS were 24% (22/93), 18% (17/93), and 19% (17/91) in the 45-mg, 30-mg, and 15-mg starting dose cohorts, respectively, and rates of ≤0.0032% BCR::ABLIS were 13% (12/93), 14% (13/93), and 15% (14/91), respectively. The estimated PFS rates at 60 months were 63%, 57%, and 60% in the 45-mg, 30-mg, and 15-mg cohorts. Estimated OS rates at 60 months were similar across starting dosing cohorts. Among pts who had dose reduction to 15 mg after achieving ≤1% BCR::ABL1IS, 29% (13/45) in the 45-mg cohort and 23% (6/26) in the 30-mg cohort lost the response after dose reduction. Of the pts in the 45-mg and 30-mg cohorts who had dose re-escalation after loss of ≤1% BCR::ABL1IS response, 69% (9/13) and 80% (4/5), respectively, regained a ≤1% BCR::ABL1IS response. The most common grade 3/4 treatment-emergent adverse events were thrombocytopenia (27%), neutropenia (18%), and hypertension (10%). Exposure-adjusted AOE rates per 100 pt-years (95% confidence interval) were similar across the 3 cohorts: 45 mg, 4.1 (1.8-6.4); 30 mg, 3.4 (1.0-5.8); 15 mg, 1.2 (0.0-2.5). For the first time, EOT mutation analyses will be shared. Among 74 pts with no baseline mutation and available EOT data, only 6 had BCR::ABL1 mutations detected; 5 received the 15-mg starting dose and 1 had the 45-mg starting dose (E255K). Conclusion: Long-term results from OPTIC highlight the clinical benefits of ponatinib in patients with CP-CML resistant to ≥2 TKIs or harboring a T315I mutation. These results are consistent with previous OPTIC analyses and demonstrate that the approved ponatinib starting dose of 45 mg QD with reduction to 15 mg QD upon attainment of ≤1% BCR::ABL1IS provides the optimal benefit:risk ratio. Mutation data from EOT samples support ponatinib suppression of emerging mutations at the approved 45-mg starting dose.

Introduction: FLT3 internal tandem duplications (ITD) are among the most frequent genetic alteration, found in approximately 30% AML, and are associated with a high risk of relapse and death. Measurable residual disease (MRD) NGS-based monitoring of FLT3-ITD mutations offers a new opportunity to detect leukemic cells during treatment. Here we aimed to retrospectively assess the prognostic value of FLT3-ITD MRD monitoring using a high sensitivity NGS-based approach in FLT3-ITD AML patients included in the AML-treated with ponatinib trial, a pan-BCR::ABL kinase inhibitor. Methods: The AML-ponatinib trial (Clinicaltrial ID: NCT02428543) included AML patients positive for FLT3-ITD by fragment analysis in complete remission. Patients then received consolidation courses (2 to 3) with the combination of ponatinib 30 mg per day and Cytarabine (HDAC for the 18-55y cohort A and IDAC for the 55-70y cohort B). Ponatinib was used as a weak FLT3 inhibitor (FLT3 IC50: 12.6 nM). In the first part of the work, FLT3-ITD MRD was monitored using 3 different techniques: 2 custom amplicon-based NGS, one according to Blätte et al (Leukemia, 2019) (AB technique), a second developed by the Toulouse team (Toulouse technique) and the last technique was a capture-based technique (capture technique) including the full sequence of FLT3 gene. For these 3 techniques, the detection and the quantification of the FLT3-ITD clones was performed using FiLT3R algorithm (4f569307). These 3 assays were compared to the reference FDA approved FLT3-ITD MRD NGS kit (IVS; Invivoscribe). Of note the 700 ng DNA input was similar for all the tests except for Toulouse (200ng). Results: Using 72 samples, the comparison between the 3 in-house techniques and the IVS kit showed the following results: 99%, 97% and 93% concordance for the AB technique, capture technique and Toulouse technique, respectively. Regarding the strict similarity between the AB technique with IVS, the same sensitivity (10-5), the good median average reads obtained on the NextSeq 1000 (Illumina) and the advantage of FiLT3r algorithm (identification of the sequence and breakpoint of the different clones), we decided to apply the AB technique to the samples of the PONATINIB-AML trial. Forty-seven patients were included, 27 in cohort A and 20 in cohort B. Median age was 57.8y (28-70), sex ratio was 0.4. NPM1 mutation was present in 36 patients (76.6%). FLT3 MRD was assessed in 40 out of 46 FLT3-ITD patients (87%). After induction (inclusion, timepoint 1 (TP1)), 25 (62.5%) and 20 (50%) of the patients achieved FLT3 MRD1 negativity at the threshold of 10-4 and 10-5 respectively. With a median follow-up of 4.1 years, FLT3 MRD negativity was associated with a strong benefit in overall survival (OS) (median survival not reached vs 1.2y in MRD1 positive patients, p=0.0003) with a 5y OS of 82.8% (95% CI:60.1-93.2). Sequential follow-up was performed in 31 patients with MRD post induction (TP1) and post consolidation 1 (TP2) with a threshold of 10-4. Median RFS was not reached, 0.8y and 0.35y for patients with neg/neg, pos/neg and pos/pos FLT3 MRD TP1/TP2 respectively (p=0.0001). NPM1 MRD was assessed at TP2 in 29 out of 36 NPM1 mutated patients (80%). Median RFS was not reached and 1y in NPM1 MRD negative and positive patients respectively (p=0.013). At TP2, MRD was assessed using NPM1 and FLT3 in 34 evaluable patients. No patients had NPM1 neg and FLT3 pos MRD. Median RFS was unreached, 1.2y and 0.2y for NPM1/FLT3 neg/neg, pos/neg and pos/pos MRD respectively (p=0.0001). Twenty-two patients relapses and 14 were evaluated for FLT3 MRD. Only 2 of them were negative, 9 had the same clone and 3 had a new FLT3-ITD clone emphasizing the major role of FLT3-ITD clones to trigger the relapse. Conclusion: In conclusion, using an external quality control based on 72 samples, we are able to identify a very good FLT3-ITD MRD technique and to validate the methodology to assess FLT3-ITD MRD with a level of sensitivity of 10-5/10-4. In this post hoc study, FLT3-ITD was a major predictor of OS and RFS, particularly if negative at TP1. Patients with delayed later negativity had lower OS and RFS. The negativity of NPM1 and FLT3-ITD MRD at TP2 is predictive of a better RFS. Our data strongly support the use of FLT3-ITD MRD to monitor FLT3-ITD AML patients.

The long-term outcome of older patients with acute lymphoblastic leukemia (ALL) is poor due to a reduced ability to tolerate intensive chemotherapy, a more aggressive disease biology, and the presence of comorbidities. Older adults with Philadelphia chromosome-negative (Ph–) B-cell ALL have the highest rates of treatment failure and complications, and the pediatric-inspired regimens that are effective in younger adults are severely limited by their toxicity in older patients. Targeted therapies, including inotuzumab ozogamicin (InO) and blinatumomab, have potent activity in B-cell ALL and are used today as single agents, and in combination with chemotherapy in both salvage and frontline ALL therapy.Optimized frontline use of B-cell targeting agents would potentially reduce the need for, and exposure to, conventional chemotherapy and improve the tolerance and efficacy of reduced-intensity chemotherapy regimens combined with targeted therapies. This review summarizes the efficacy and safety results of several recent trials investigating different approaches with InO as first-line therapy in patients with Ph– B-cell ALL.

Supplementary Table 1. Karyotypes of LH-ALL patients at diagnosis. Supplementary Table 2. Somatic variants detected in LH-ALL patients at diagnosis. Supplementary Table 3. ARCH related variants detected in LH-ALL patients at remission. Supplementary Table 4. Minimal residual disease values of remission samples used for mutation analysis. Supplementary Table 5. Somatic alterations in cell populations from diagnostic samples (BMMC) based on single-cell analyses. Supplementary Table 6. Somatic alterations in FACS-sorted cell populations from diagnostic samples. Supplementary Table 7. Panel of genes for targeted sequencing. Supplementary Table 8. Single cell DNA amplicons for genotyping and LOH analyses. Supplementary Table 9. Single cell DNA amplicons for B-ALL clono-specific IG/TR detection. Supplementary Table 10. ADT-seq panel and spike-in antibodies. Supplementary Table 11. Single cell sequencing metrics.

:ABL1 tyrosine kinase inhibitors (TKIs) plus reduced intensity chemotherapy are considered standard of care for older patients (pts) with newly diagnosed Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL), but disease progression is common with first- or second-generation TKI. A recent registration trial (Jabbour E et al, JAMA 2024;331:1814-23) in adult patients indicates that the 3rd-generation TKI ponatinib (PON) induces a higher rate of molecular responses than imatinib (IM) when combined with chemotherapy. Moreover, the bispecific T-cell engager blinatumomab (BLIN) has emerged as a potent front-line modality in Ph+ALL. This randomized European Working Group on Adult ALL (EWALL) PH03 study (EudraCT: 2018-003350-25) was initially designed as a three-arm trial to compare PON with IM in combination with chemotherapy in older pts with Ph+ALL, a third exploratory chemotherapy-free study arm combined PON with BLIN. Eligible pts were ≥55y with newly diagnosed Ph+ ALL, an ECOG performance status score ≤2, and no clinically significant or uncontrolled cardiovascular or central nervous system disease. Patients were initially randomized in a 1:1:1 ratio, to receive the EWALL reduced-intensity chemotherapy (Rousselot et al, Blood,2016;128:774-82) combined with either PON (30mg/d)(Arm 1) or IM (800mg/d during induction, 600mg/d thereafter)(Arm 2) or PON combined with 5 cycles BLIN (Arm 3). CNS-directed prophylaxis was given per EWALL backbone. Following withdrawal of support for BLIN, the trial was amended to a two-armed trial with 1:1 randomization between IM and PON. Primary end point of this trial was measurable residual disease (MRD)-response (≤0.01% BCR::ABL1 [MR4]) after consolidation cycle 2, centrally assessed by qRT-PCR. Key secondary end point was event-free survival (EFS). 72 pts (median age, 66.8y; 29 [40.3%] female) were randomized (PON:n=36; IM:n=36) into study arms 1 and 2 and are included in this interim analysis, 10 pts were randomized to the PON+BLIN arms and will be reported separately. The complete remission rate after induction was 94% and 91% with PON and IM, respectively. 3 pts died (PON:n=2; IM:n=1) before reaching the primary endpoint (pre-consolidation 3) and 3 pts withdrew from trial treatment. The primary endpoint analysis (n=66 pts) showed a molecular remission (BCR::ABL1IS ≤0.01%; MR4) in 64.7% (22/34 evaluable pts.) treated with PON and 43.8% (14/32 pts.) treated with IM (p=0.11). Complete molecular remissions (BCR-ABL not detectable (<0,0032%) with a quantitative range ≥10-4.5) were achieved by 12/34 pts. (35.3%) and 9/32 pts. (28.1%) in the PON and IM arms, respectively. Up to the primary endpoint, 3 pts died (PON: n=2; IM: n=1) and 13 withdrew from trial treatment (PON: n=4, 11.1%; IM: n=9, 25%). Main reasons for withdrawal from study treatment were transfer to allogeneic stem cell transplantation (PON:n=2; IM:n=1), relapse (PON:n=0; IM:n=1) and intolerance to trial medication (PON:n=0; IM:n=2). Adverse event rates were comparable between the PON and IM groups, including grade (G) 3 or 4 treatment-emergent adverse events (TEAEs) and treatment-related adverse events (65.6% and 59.3%, respectively). The most common G3 or G4 hematologic TEAEs were decreased platelet count (PON, 72.2%; IM, 77.8%), WBC count (66.7% and 86.1%, respectively), and ANC (77.8% and 88.9%, respectively). The most common G3 or G4 non-hematologic TEAEs were increased alanine aminotransferase (PON, 27.8%; IM, 2.8%) and increased lipase (8.3% and 0%, respectively), hypertension (11.1% and 2.8% respectively) and hypokalemia (0% and 5.6%, respectively). Pancreatitis occurred in 8.3% of pts in the PON group and 0% of pts in the IM group (no serious events). There was no significant difference in the incidence of severe cardiovascular events (PON:n=2; IM:n=0). Peripheral arterial occlusive disease and venous thrombosis (both G3) occurred in 2/36 pts receiving PON. For all pts (n=72), median EFS and overall survival was 6.44 months (IQR:2.6-12.06; range: 0.66-15.47) and 16.07 months (IQR: 2.96-17.28; range: 0.66-30.36), respectively. Conclusion: In older pts with Ph+ALL receiving upfront reduced-intensity chemotherapy (EWALL), PON induces a higher, albeit not significant, deep molecular response rate compared to IM, The safety profile of PON was consistent with known AEs and did not lead to a higher rate of withdrawals from study treatment than IM. The impact on survival will require longer follow-up.

In chronic myeloid leukemia (CML), the role of immune effectors has been suggested in the achievement of a sustained deep molecular response (DMR) and treatment-free remission (TFR) after tyrosine kinase inhibitor (TKI) discontinuation. A contributory role of the distinct new innate CD8 T-cell pool in control of CML residual disease after TKI cessation was recently highlighted. Here, we evaluated longitudinally whether innate CD8 T-cells predict CML therapy success in a cohort of newly diagnosed CML patients treated in the DASA-PegIFN clinical trial. After 3 months of treatment (M3), we observed a significant increase in innate CD8 T-cell frequency as compared to diagnosis, together with an early shift within the pool of CD8 T-cells toward an innate/memory phenotype. We also found that patients with high innate CD8 T-cell frequency at M3 achieved DMR earlier and at higher rates than patients with low innate CD8 T-cell frequency. Remarkably, this signature pre-existed at the time of diagnosis, suggesting the possible role of the patient’s initial individual immune status. High innate CD8 T-cell frequency was also associated with maintaining DMR stability for 2 years. Taken together, our findings highlight innate CD8 T-cells as a potential marker for CML therapy success and TFR eligibility.

The deregulated activation of the phosphoinositide 3-kinase (PI3K) pathway is a hallmark of aggressive tumors with metabolic plasticity, eliciting their adaptation to the microenvironment and resistance to chemotherapy. A significant gap lies between the biological features of PI3K-driven tumors and the specific targeting of their vulnerabilities. Here, we explore the metabolic liabilities of PI3K-altered T-cell acute lymphoblastic leukemia (T-ALL), an aggressive hematological cancer with dismal outcomes. We report a metabolic crosstalk linking glutaminolysis and glycolysis driven by PI3K signaling alterations. Pharmaceutical inhibition of mTOR reveals the singular plasticity of PI3K-altered cells toward the mobilization of glutamine as a salvage pathway to ensure their survival. Subsequently, the combination of glutamine degradation and mTOR inhibition demonstrates robust cytotoxicity in PI3K-driven solid and hematological tumors in pre-clinical and clinical settings. We propose a novel therapeutic strategy to circumvent metabolic adaptation and efficiently target PI3K-driven cancer.

OBJECTIVE:New therapeutic classes of chemotherapy, including tyrosine kinase inhibitors (TKIs), are being developed, leading to unexpected cutaneous side-effects. The aim was to analyse the development of leg ulcers (LUs) associated with chemotherapy to identify their characteristics and management. METHOD:A retrospective multicentre study was conducted across nine French dermatology departments and one haematology department. We collected information on cancer history, cofactors of LUs, and management and evolution of the LUs. RESULTS:The study included 45 patients divided into three groups: hydroxyurea treatment; targeted therapies including TKIs; and taxane treatment. Certain factors were common for arteriovenous leg ulcers, especially advanced age, the frequency of vascular cofactors and the painful nature of the ulcer; however, significant differences were apparent. In particular, the delay between the introduction of chemotherapy and the beginning of the LU. The delay in appearance of the LU was shorter for patients in the taxanes and TKIs groups versus patients treated with hydroxyurea (hydroxyurea versus taxanes: p<0.0001; hydroxyurea versus TKIs: p=0.004). Following the appearance of the LU, treatment was normally stopped (88%), with cicatrisation (91%) occurring within a period of 4.6 months on average. These results confirm the known association of hydroxyurea and LUs; however, other chemotherapies, including targeted therapies and taxanes, appear to be involved. CONCLUSION:Prescribers should be made aware of skin side-effects of chemotherapies and the risk-benefit of discontinuing chemotherapy for ulcer healing should be raised. Closer monitoring to control identified cofactors of LUs is required in patients receiving this type of chemotherapy, especially if they have LU-predisposing factors.

The French Stop Imatinib study (STIM1) was one of the first trials to explore the possibility of discontinuing imatinib in patients with chronic myeloid leukemia (CML) who had achieved a sustained molecular response (at least a 4.5-log reduction). The stringent criteria for molecular recurrence (MRec) were defined as BCR::ABL1 transcript positivity confirmed by a second test showing either a 1-log increase or loss of major molecular response across consecutive assessments. This comprehensive update presents long-term follow-up data from the STIM1 study, with a median molecular follow-up of 12.8 years (range, 0.8-15). Results showed a molecular recurrence-free survival rate of 37% (95% confidence interval [CI], 28-48) at 120 months, and 35% (95% CI, 26-46) at 156 months after imatinib discontinuation. Importantly, no patients experienced CML progression during the follow-up. Overall survival rates were 97% (95% CI, 94-100) at 10 years and 88% (95% CI, 81-96) at 20 years. A case of late MRec, confirmed through DNA BCR::ABL1 breakpoint analysis and comparison at diagnosis and recurrence, indicated the persistence of the original disease rather than the onset of new CML. This study offers valuable insights into the safety and feasibility of imatinib discontinuation for patients with CML, supporting long-term remission while maintaining survival. This study was registered at ClinicalTrials.gov as #NCT00478985.