Prediction of sustained remission after tyrosine kinase inhibitor discontinuation with BCR::ABL1 digital PCR in chronic myeloid leukemia patients.

Precise and reliable predictive parameters to accurately identify chronic myeloid leukemia (CML) patients who can successfully discontinue their tyrosine kinase inhibitor (TKI) treatment are lacking. One promising parameter is depth of molecular response measured by BCR::ABL1 digital PCR (dPCR). The aim of this study was to validate a previously described prediction cutoff of 0.0023%IS and to assess the value of dPCR for treatment-free remission (TFR) prediction in relation to other clinical parameters. A droplet-based dPCR assay assessed BCR::ABL1 %IS prior to TKI discontinuation. The primary endpoint was molecular recurrence (MolR) by 36 months. A total of 186 patients from Canada, Germany, and the Netherlands were included. In patients with a first TKI discontinuation attempt (n = 163), a BCR::ABL1 dPCR < and ≥0.0023%IS had a MolR probability of 33% and 70%, respectively. Patients treated less than 6 years with a BCR::ABL1 dPCR <0.0023%IS had a MolR probability of 31%. After correction for treatment duration, both high dPCR value and the use of imatinib (vs. second-generation TKI) were significantly associated with a higher risk of MolR (HR of 3.66, 95%CI 2.06-6.51, p < .001; and 2.85, 95%CI 1.25-6.46, p = .013, respectively). BCR::ABL1 dPCR was not associated with TFR outcome after second TKI discontinuation, however, with the limitation of a small number of patients analyzed (n = 23). In conclusion, BCR::ABL1 digital PCR based on the cutoff of 0.0023%IS is a valuable predictive tool to identify CML patients with a high probability of TFR success after first TKI discontinuation, including patients treated for less than 6 years.

Kockerols C ，Valk PJM ，Janssen JJWM ，Hogenbirk P ，Cornelissen JJ ，Saussele S ，Spiess B ，Perusini MA ，Kim D ，Westerweel PE ... -  《-》

Decitabine, venetoclax, and ponatinib for advanced phase chronic myeloid leukaemia and Philadelphia chromosome-positive acute myeloid leukaemia: a single-arm, single-centre phase 2 trial.

Advanced phase Philadelphia chromosome-positive myeloid disease-consisting of chronic myeloid leukaemia in the myeloid blast phase and in the accelerated phase, and Philadelphia chromosome-positive acute myeloid leukaemia-is associated with poor outcomes. Although previous studies have suggested the benefit of chemotherapy and BCR::ABL1 tyrosine kinase inhibitor combinations, the optimal regimen is uncertain and prospective studies for this rare group of diseases are scant. Preclinical and retrospective clinical data suggest possible synergy between the BCL-2 inhibitor venetoclax and BCR::ABL1 tyrosine kinase inhibitors. We therefore aimed to design a study to evaluate the safety and activity of a novel combination of decitabine, venetoclax, and the third-generation BCR::ABL1 tyrosine kinase inhibitor ponatinib in advanced phase Philadelphia chromosome-positive myeloid diseases. For this phase 2 study, patients aged 18 years or older with previously untreated or relapsed or refractory myeloid chronic myeloid leukaemia-blast phase, chronic myeloid leukaemia-accelerated phase, or advanced phase Philadelphia chromosome-positive acute myeloid leukaemia, and an Eastern Cooperative Oncology Group performance status of 0-3 were eligible. Patients were eligible regardless of the number of previous lines of therapy received or previous receipt of ponatinib. Cycle 1 (induction) consisted of a 7-day lead-in of ponatinib 45 mg orally daily (days 1-7), followed by combination therapy with decitabine 20 mg/m2 intravenously on days 8-12, venetoclax orally daily with ramp-up to a maximum dose of 400 mg on days 8-28, and ponatinib 45 mg orally daily on days 8-28. Cycles 2-24 consisted of decitabine 20 mg/m2 intravenously on days 1-5, venetoclax orally 400 mg on days 1-21, and ponatinib orally daily on days 1-28. Response-based dosing of ponatinib was implemented in consolidation cycles, with reduction to 30 mg daily in patients who reached complete remission or complete remission with an incomplete haematological recovery and a reduction to 15 mg daily in patients with undetectable BCR::ABL1 transcripts. The primary endpoint was the composite rate of complete remission or complete remission with incomplete haematological recovery in the intention-to-treat population. Safety was assessed in the intention-to-treat population. This trial was registered with ClinicalTrials.gov (NCT04188405) and is still ongoing. Between July 12, 2020, and July 8, 2023, 20 patients were treated (14 with chronic myeloid leukaemia-blast phase, four with chronic myeloid leukaemia-accelerated phase, and two with advanced phase Philadelphia chromosome-positive acute myeloid leukaemia). The median age was 43 years (IQR 32-58); 13 (65%) patients were male and seven (35%) were female; and 12 (60%) were White, three (15%) were Hispanic, four (20%) were Black, and one (5%) was Asian. 12 (60%) patients had received 2 or more previous BCR::ABL1 tyrosine kinase inhibitors, and 14 (70%) patients had at least one high-risk additional chromosomal abnormality or complex karyotype. The median duration of follow-up was 21·2 months (IQR 14·1-24·2). The complete remission or complete remission with an incomplete haematological recovery rate was 50% (10 of 20 patients); complete remission in one [5%] patient and complete remission with incomplete haematological recovery in nine [45%]). An additional six (30%) patients had a morphologic leukaemia-free state. The most common grade 3-4 non-haematological adverse events were febrile neutropenia in eight (40%) patients, infection in six (30%), and alanine or aspartate transaminase elevation in five (25%). Eight (40%) patients had at least one cardiovascular event of any grade. There were three on-study deaths, none of which was considered related to the study treatment and all from infections in the setting of refractory leukaemia. The combination of decitabine, venetoclax, and ponatinib is safe and shows promising activity in patients with advanced phase chronic myeloid leukaemia, including those with multiple previous therapies or high-risk disease features. Further studies evaluating chemotherapy and venetoclax-based combination strategies using newer-generation BCR::ABL1 tyrosine kinase inhibitors are warranted. Takeda Oncology, the National Institutes of Health, and the National Cancer Institute Cancer Center.

Short NJ ，Nguyen D ，Jabbour E ，Senapati J ，Zeng Z ，Issa GC ，Abbas H ，Nasnas C ，Qiao W ，Huang X ，Borthakur G ，Chien K ，Haddad FG ，Pemmaraju N ，Karrar OS ，Nguyen D ，Konopleva M ，Kantarjian H ，Ravandi F ... -  《Lancet Haematology》

Mutation analysis of BCR-ABL1 kinase domain in chronic myeloid leukemia patients with tyrosine kinase inhibitors resistance: a Malaysian cohort study.

Mutational analysis of BCR::ABL1 kinase domain (KD) is a crucial component of clinical decision algorithms for chronic myeloid leukemia (CML) patients with failure or warning responses to tyrosine kinase inhibitor (TKI) therapy. This study aimed to detect BCR::ABL1 KD mutations in CML patients with treatment resistance and assess the concordance between NGS (next generation sequencing) and Sanger sequencing (SS) in detecting these mutations. In total, 12 different BCR::ABL1 KD mutations were identified by SS in 22.6% (19/84) of patients who were resistant to TKI treatment. Interestingly, NGS analysis of the same patient group revealed an additional four different BCR::ABL1 KD mutations in 27.4% (23/84) of patients. These mutations are M244V, A344V, E355A, and E459K with variant read frequency below 15%. No mutation was detected in 18 patients with optimal response to TKI therapy. Resistance to TKIs is associated with the acquisition of additional mutations in BCR::ABL1 KD after treatment with TKIs. Additionally, the use of NGS is advised for accurately determining the mutation status of BCR::ABL1 KD, particularly in cases where the allele frequency is low, and for identifying mutations across multiple exons simultaneously. Therefore, the utilization of NGS as a diagnostic platform for this test is very promising to guide therapeutic decision-making.

Seman ZA ，Ahid F ，Kamaluddin NR ，Sahid ENM ，Esa E ，Said SSM ，Azman N ，Mat WKDW ，Abdullah J ，Ali NA ，Khalid MKNM ，Yusoff YM ... -  《-》

Asciminib in Newly Diagnosed Chronic Myeloid Leukemia.

Patients with newly diagnosed chronic myeloid leukemia (CML) need long-term therapy with high efficacy and safety. Asciminib, a BCR::ABL1 inhibitor specifically targeting the ABL myristoyl pocket, may offer better efficacy and safety and fewer side effects than currently available frontline ATP-competitive tyrosine kinase inhibitors (TKIs). In a phase 3 trial, patients with newly diagnosed CML were randomly assigned in a 1:1 ratio to receive either asciminib (80 mg once daily) or an investigator-selected TKI, with randomization stratified by European Treatment and Outcome Study long-term survival score category (low, intermediate, or high risk) and by TKI selected by investigators before randomization (including imatinib and second-generation TKIs). The primary end points were major molecular response (defined as BCR::ABL1 transcript levels ≤0.1% on the International Scale [IS]) at week 48, for comparisons between asciminib and investigator-selected TKIs and between asciminib and investigator-selected TKIs in the prerandomization-selected imatinib stratum. A total of 201 patients were assigned to receive asciminib and 204 to receive investigator-selected TKIs. The median follow-up was 16.3 months in the asciminib group and 15.7 months in the investigator-selected TKI group. A major molecular response at week 48 occurred in 67.7% of patients in the asciminib group, as compared with 49.0% in the investigator-selected TKI group (difference, 18.9 percentage points; 95% confidence interval [CI], 9.6 to 28.2; adjusted two-sided P<0.001]), and in 69.3% of patients in the asciminib group as compared with 40.2% in the imatinib group within the imatinib stratum (difference, 29.6 percentage points; 95% CI, 16.9 to 42.2; adjusted two-sided P<0.001). The percentage of patients with a major molecular response at week 48 was 66.0% with asciminib and 57.8% with TKIs in the second-generation TKI stratum (difference, 8.2 percentage points; 95% CI, -5.1 to 21.5). Adverse events of grade 3 or higher and events leading to discontinuation of the trial regimen were less frequent with asciminib (38.0% and 4.5%, respectively) than with imatinib (44.4% and 11.1%) and second-generation TKIs (54.9% and 9.8%). In this trial comparing asciminib with investigator-selected TKIs and imatinib, asciminib showed superior efficacy and a favorable safety profile in patients with newly diagnosed chronic-phase CML. Direct comparison between asciminib and second-generation TKIs was not a primary objective. (Funded by Novartis; ASC4FIRST ClinicalTrials.gov number, NCT04971226).

Hochhaus A ，Wang J ，Kim DW ，Kim DDH ，Mayer J ，Goh YT ，le Coutre P ，Takahashi N ，Kim I ，Etienne G ，Andorsky D ，Issa GC ，Larson RA ，Bombaci F ，Kapoor S ，McCulloch T ，Malek K ，Yau L ，Ifrah S ，Hoch M ，Cortes JE ，Hughes TP ，ASC4FIRST Investigators ... -  《-》

Novel ABL1 mutation in a Moroccan CML patient with Imatinib resistance.

Tyrosine Kinase Inhibitors (TKI), such as Imatinib, are known for their effectiveness in achieving complete remission from Chronic Myeloid Leukemia (CML), a malignancy caused by a reciprocal translocation between the terminal fragments of the long arms of chromosomes 9 and 22 that leads to the famous chimeric BCR::ABL1 gene. Mutations in this fusion gene may induce resistance to TKI treatment, which requires prescribing a second-, or third-generation TKI medication. We report here a case of a Moroccan CML patient with secondary resistance to the frontline TKI treatment (Imatinib), in which, BCR::ABL1 cDNA sequencing reveals the novel mutation p.K375M at the ABL1 Kinase Domain. In-silico prediction tools confirm the pathogenicity of the p.K375M substitution. Homology analysis indicated that the residue is highly conserved and located in a stable region. This potentially pathogenic mutation is likely to disrupt the BCR::ABL1-Imatinib binding, leading to the observed resistance. To overcome the treatment resistance, Imatinib should be substituted with a second-generation TKI medication, such as Dasatinib, Bosutinib, or Nilotinib. The present study further widens the spectrum of TKI resistance mutations and emphasizes particularly the crucial role of molecular investigation in personalizing treatment for CML patients, ensuring efficient follow-up and appropriate healthcare.

El Bouchikhi I ，Azami Idrissi H ，Lazraq A ，El Makhzen B ，Ahakoud M ，Berrady R ，Ouldim K ，Bouguenouch L ，El-Azami-El-Idrissi M ... -  《Cancer Genetics》