Discontinuation of Tyrosine Kinase Inhibitor Therapy and Treatment Free Remission (TFR) in Chronic Myeloid Leukemia: Successful Achievement of TFR in More Than Two-Third of Patients in a Real-World Practice.

Discontinuation of TKI therapy and treatment-free remission (TFR) have become new goals for chronic-phase chronic myeloid leukemia (CP-CML). The aim of this study was to estimate the TFR post discontinuation of TKI therapy at 3 tertiary-care centers. CP-CML patients aged ≥16 years who had an attempt to discontinue TKI therapy till June 2022, were eligible. The collected data included patients' demographics, prognostic score, type and duration of TKI therapy, response dates, relapse dates, response to re-initiation of TKI therapy, and risk factors for relapse. Fifty-five patients (35, 63.6% females) with a median age of 40 (range 16-74) years at diagnosis discontinued therapy. Forty-eight (87.3%) patients received imatinib as first line therapy. Twenty-nine (52.7%) patients were receiving imatinib at the time of TKI-discontinuation. Median time from diagnosis to TKI discontinuation was 86 months (IQR 60;132) and median duration of TKI therapy after achieving DMR was 66 months (IQR 47;114). After a median follow up of 34 (IQR 12;68) months, 15 (27.3%) patients relapsed. Median time to relapse was 5 months (range 2-38). Most of the relapses occurred during the first 6 months except 3 (20%) patients. All the relapsed patients achieved MMR after a median of 3 (range 2-6) months after restarting TKI therapy. None of the patients progressed to advanced-phase. Our experience confirms that discontinuation of TKI therapy in CP-CML patients is feasible and safe in routine clinical practice, and can achieve TFR in more than two-third of carefully selected patients.

Aleem A ，Shaheen NA ，Algahtani F ，Jamal A ，Alkhudair N ，Alghafis M ，Iqbal Z ，Siti HWZ ，Thomas A ，Alahmari B ，Salama H ，Gmati G ，Alzahrani M ，Alhejazi A ，Alfayez M ，Alrajhi A ，Marei MA ，Alaskar A ... -  《-》

Deep Molecular Response Rate in Chronic Phase Chronic Myeloid Leukemia: Eligibility to Discontinuation Related to Time to Response and Different Frontline TKI in the Experience of the Gimema Labnet CML National Network.

In the last decade, TKIs improved the overall survival (OS) of chronic myeloid leukemia (CML) patients who achieved a deep and sustained molecular response (DMR, defined as stable MR4 and MR4.5). Those patients may attempt therapy discontinuation. In our analysis, we report the differences in eligibility criteria due to time of response and different TKI used as frontline treatment analyzed in a large cohort of CP-CML patients. Data were exported by LabNet CML, a network founded by GIMEMA in 2014. The network standardized and harmonized the molecular methodology among 51 laboratories distributed all over Italy for the diagnosis and molecular residual disease (MRD) monitoring. Out of 1777 patients analyzed, 774 had all evaluable timepoints (3, 6, and 12 months). At 3 months, 40 patients obtained ≥MR4: of them 14 (3.6%) with imatinib, 8 (5.8%) with dasatinib, and 18 (7.4%) with nilotinib (P = .093); at 6 months, 146 patients were in MR4: 42 (11%) with imatinib, 38 (28%) with dasatinib, and 66 (27%) with nilotinib (P < .001). At 12 months, 231 patients achieved a DMR: 85 (22%) with imatinib, 55 (40%) with dasatinib and 91 (38%) with nilotinib (P < .001). Achieving at least ≥MR2 at 3 months, was predictive of a DMR at any timepoint of observation: with imatinib 67% versus 30% of patients with <MR2, with dasatinib 66% versus 28% of patients with <MR2, and with nilotinib 75% versus 30% of patients with < MR2 (P < .001). At the same time point, achieving at least ≥MR3 is even more predictive of a DMR at any timepoint: 89% versus 38% of patients with <MR3 with imatinib (P < .001), 84% versus 40% of patients with <MR3 with dasatinib (P < .001), and 89% versus 49% of patients with <MR3 with nilotinib (P < .001). Of 908 patients who reached a DMR, 461 (51%) lost it: the loss of response after >2 years was significant for patients who at 3 months had ≥MR2 (18% vs. 9.9% of pts with <MR2, P = .038). In conclusion, reaching ≥MR2 and a MR3 at 3 months it seems predictive of a DMR at any time point. Considering the prerequisite for a discontinuation with a sustained DMR only a minority of patients can be eligible for the discontinuation, regardless the frontline treatment received.

Breccia M ，Cucci R ，Marsili G ，Castagnetti F ，Galimberti S ，Izzo B ，Sorà F ，Soverini S ，Messina M ，Piciocchi A ，Bonifacio M ，Cilloni D ，Iurlo A ，Martinelli G ，Rosti G ，Stagno F ，Fazi P ，Vignetti M ，Pane F ... -  《-》

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》

Outcomes of pregnancy in patients with chronic myeloid leukemia in the era of tyrosine kinase inhibitors.

Young female patients with chronic myeloid leukemia (CML) often face challenges becoming pregnant due to the teratogenicity of tyrosine kinase inhibitors (TKIs). The authors conducted a nationwide survey of female patients with CML who experienced pregnancy between 2002 and 2020. Information for 70 pregnancies in 49 patients was obtained. There were three types of pregnancies: CML onset during pregnancy (n = 9), unplanned pregnancy mostly during treatment with a TKI (n = 25), and planned pregnancy during treatment-free remission (TFR) or treatment with interferon-alpha (IFN-α) (n = 36). The median duration from CML diagnosis to pregnancy in patients with planned pregnancy was significantly longer than that in patients with unplanned pregnancy (10.6 years vs. 4.1 years, p < .001). In 48 pregnancies that resulted in childbirth, TFR and treatment with IFN-α were chosen in 26 and 17 pregnancies, respectively. Sustained major or deeper molecular response was observed in 18 of 26 pregnancies with TFR. The patients who fulfilled the requirements for TKI therapy discontinuation by European LeukemiaNet recommendations achieved a TFR rate of 77% in pregnancy. Treatment with IFN-α might be effective for patients who are in complete cytogenetic response or deeper response (response rate, 76%). Pregnancy by TFR or treatment with IFN-α could be a safe and feasible way for patients with CML. However, a substantial duration of treatment with a TKI before conception may be needed for planned pregnancy. Planning and evaluation for pregnancy should be considered at the time of CML onset for female patients with childbearing potential.

Kondo T ，Matsuki E ，Takaku T ，Watanabe N ，Yoshida C ，Okada M ，Murai K ，Kodama T ，Takahashi N ，Kimura S ，Matsumura I ，Preg‐CML/Japan Study Investigators ... -  《-》