BCR-ABL Transcript Research Articles

Assessment of regulatory T cells (Tregs) and Foxp3 methylation level in chronic myeloid leukemia patients on tyrosine kinase inhibitor therapy.

The key cell population permits cancer cells to avoid immune-surveillance is regulatory T cells (Tregs). This study evaluates the level of Tregs in chronic myeloid leukemia (CML) patients and the effect of Tyrosine kinase inhibitor (TKI) on Treg levels, as a pathway to understand the immune response and behavior among advance stage and optimal response CML patients using imatinib therapy. Blood samples were collected from 30 CML patients (optimal response to TKI), 30 CML patients (failure response to TKI), and 30 age- and gender-matched controls. Analysis involved measuring percentages of Tregs (CD4 + CD25 + FOXP3 +) by flow cytometer and demethylation levels of FOXP3 Treg-specific demethylated region (TSDR) by PCR. The data revealed that Tregs and the FOXP3-TSDR demethylation percentages significantly increased in failure response group in comparison to the optimal response and control groups, while no significant difference between optimal response and control groups. Tregs and FOXP3 TSDR demethylation percentages showed high sensitivity and specificity, suggesting powerful discriminatory biomarkers between failure and optimal groups. An assessment of the Tregs and demethylation percentage among different BCR-ABL levels of CML patients on TKI revealed no significant differences in parameter percentage in the optimal response to TKI patients with different molecular responses (log 3 reduction or other deeper log 4.5 and 5 reduction levels). Our findings demonstrate an effective role of functional Tregs among different CML stages. Also, the study suggests that the major molecular response to therapy at level 0.1% of BCR-ABL transcript could be enough to induce immune system restoration in patients.

Transplantation in CML in the TKI era: who, when, and how?

Molecular therapy with tyrosine kinase inhibitors (TKIs) has significantly reduced the indication for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in chronic myeloid leukemia (CML). Treatment-free remission can be obtained in about 50% of patients with an optimal response. However, cure rates up to 90% are restricted to patients receiving HSCT. Timing is essential since HSCT in the early stages of the disease has the best outcome. Patients in a more advanced phase (AdP) than chronic-phase (chP) CML undergo HSCT with suboptimal outcomes, and the gap between chP and AdP disease is widening. First-line therapy should start with first- or second-generation (G) TKIs. Patients failing treatment (BCR-ABL1 transcripts of greater than 10% at 3 and 6 months and greater than 1% at 12 months) should be switched to second-line TKIs, and HSCT should be considered. Patients not responding to 2G-TKI therapy as well as patients in an accelerated phase (AP) or blast crisis (BC) are candidates for HSCT. Therapy resistant BCR-ABL1 mutations, high-risk additional cytogenetic abnormalities, and molecular signs of leukemia progression should trigger the indication for HSCT. Patients who, despite dose adjustments, do not tolerate or develop severe adverse events, including vascular events, to multiple TKIs are also candidates for HSCT. In AdP CML, TKIs do not show long-lasting results, and the outcome of HSCT is less optimal without pretransplant therapy. In these patients the induction of chP2 with TKIs, either alone (AP) or in combination with intensive chemotherapy (BC), followed by HSCT should be pursued.

The role of miRNA -181C between different BCR-ABL p210 transcript levels and between different levels of imatinib optimal response in CML patients

BackgroundThe development of cancer is just one of the many effects of dysregulation of miRNA expression patterns, miRNA have been found to express abnormally in hematological neoplasia such as chronic myeloid leukemia and solid malignancies. Resistance and the degree of response following TKI treatment are correlated with miRNA expression. Hence, in this study we tried to study the relationship of miRNA- 181c between different p210 BCR-ABL transcript levels and the role miRNA-181c between different levels of imatinib optimal response in CML. MethodOur study included sixty CML patients they were divided into two groups based on response to imatinib therapy, thirty samples optimal molecular response of CML patients and thirty samples of failure molecular response CML patients. Thirty samples of apparently healthy volunteers were included and evaluated as control. ResultsAccording the P210 BCR-ABL% results there was a significant difference (P ≤ 0.0001), between the responder and the failure response CML patients, assessed the expression of the level miRNA-181c the result showed high significant difference between both CML patients groups (P = 0.0012). Assessed the expression of the level miRNA-181c in different responses and failure response of CML patients, there was a significant difference of miRNA-181c level among different responses groups and failure response of CML patients (P = 0.0044). A cutoff value of response vs. failure response (7.24) with high sensitivity can be of diagnostic value to differentiate between response and failure response. ConclusionChanging gene expression with different amounts of miRNAs has an impact on drug-gene interactions, with consequences for cell growth and death. Gene expression different level miRNA-181c among of CML patients of imatinib therapy were high expression in response patients than failure response patients. The gene expression level of miRNA-181c differs between through different response CML patients.

Ponatinib and blinatumomab for Philadelphia chromosome-positive acute lymphoblastic leukaemia: a US, single-centre, single-arm, phase 2 trial

Ponatinib and blinatumomab are effective therapies in patients with Philadelphia chromosome-positive (Ph-positive) acute lymphoblastic leukaemia, and their combination might be a promising treatment option. In this study, we aimed to evaluate this chemotherapy-free strategy. We did a single-centre, single-arm, phase 2 study at the University of Texas MD Anderson Cancer Center, Houston, TX, USA, in patients aged 18 years or older with newly diagnosed or relapsed or refractory Ph-positive acute lymphoblastic leukaemia or chronic myeloid leukaemia in lymphoid blast phase. Patients with an ECOG performance status of 2 or less who had a total bilirubin concentration two-times the upper limit of normal (ULN) or less (≤2·4 mg/dL), alanine aminotransferase and aspartate aminotransferase concentration no more than three-times the ULN, and serum lipase and amylase concentrations no more than three-times the ULN were eligible for inclusion. Ponatinib 30 mg orally and continuous intravenous blinatumomab 28 μg over 24 h (for 28 days each cycle) were given in combination for up to five 42-day cycles, followed by ponatinib monotherapy. Patients received 12 doses of intrathecal chemotherapy as CNS prophylaxis. The primary endpoints were complete molecular response (defined as absence of a detectable BCR-ABL1 transcript by PCR at a sensitivity of 0·01%) in patients with newly diagnosed disease and overall response in patients with relapsed or refractory disease or chronic myeloid leukaemia in lymphoid blast phase. All assessments were done according to the intention-to-treat principle. The trial completed its original target accrual and was amended on March 23, 2022, to enrol an additional 30 patients, thus increasing the sample size to 90 patients. The trial is registered with ClinicalTrials.gov, NCT03263572, and it is ongoing. Between Feb 6, 2018, to May 6, 2022, 60 (83%) of 72 patients assessed were enrolled and received ponatinib and blinatumomab (40 [67%] patients had newly diagnosed Ph-positive acute lymphoblastic leukaemia, 14 [23%] had relapsed or refractory Ph-positive acute lymphoblastic leukaemia, and six [10%] had chronic myeloid leukaemia in lymphoid blast phase). 32 (53%) patients were men and 28 (47%) were women; 51 (85%) patients were White or Hispanic; and the median age of participants was 51 years (IQR 36-68). The median duration of follow-up for the entire cohort was 16 months (IQR 11-24). Of patients with newly diagnosed Ph-positive acute lymphoblastic leukaemia, 33 (87%) of 38 evaluable patients had a complete molecular response. 12 (92%) of 13 evaluable patients with relapsed or refractory Ph-positive acute lymphoblastic leukaemia had an overall response. 11 (79%) had a complete molecular response. Five (83%) of six patients with chronic myeloid leukaemia in lymphoid blast phase had an overall response. Two (33%) had a complete molecular response. The most common grade 3-4 adverse events that occurred in more than 5% of patients were infection (22 [37%] patients), increased amylase or lipase concentration (five [8%] patients), increased alanine aminotransferase or aspartate aminotransferase concentration (four [7%] patients), pain (four [7%] patients), and hypertension (four [7%] patients). One (2%) patient discontinued blinatumomab due to tremor. Three (5%) patients discontinued ponatinib secondary to cerebrovascular ischaemia, portal vein thrombosis, and coronary artery stenosis in one patient each. No treatment-related deaths were observed. The chemotherapy-free combination of ponatinib and blinatumomab resulted in high rates of complete molecular response in patients with newly diagnosed and relapsed or refractory Ph-positive acute lymphoblastic leukaemia. Patients with newly diagnosed Ph-positive acute lymphoblastic leukaemia could be spared the toxicities associated with chemotherapy and the need for allogeneic haematopoietic stem-cell transplantation in first response. Takeda Oncology and Amgen.

The First Report of Third-Generation TKI Olverembatinib in Adult Ph/BCR-ABL1-Positive Acute Lymphoblastic Leukemia with T315I Mutation and Relapsed Disease

Background Tyrosine kinase inhibitors (TKIs) have significantly improved the prognosis of patients(pts) with Ph/BCR-ABL1-positive (Ph/BCR-ABL1+) acute lymphoblastic leukemia (ALL). However, mutations in the ABL1 kinase domain, especially T315I, are the main mechanism of resistance to the first- or second-generation TKIs. Olverembatinib is a novel third-generation TKI developed in China and approved in Dec. 2021, which has been demonstrated great efficacy and safety in clinical trials of CML with T315I mutation. Our study is the first application of Olverembatinib in adult Ph/BCR-ABL1+ ALL with T315I mutation. Herein, we report the preliminary results. Methods In this exploratory study, adult Ph/BCR-ABL1+ ALL pts with T315I mutation or disease progression were treated with olverembatinib monotherapy (40 mg, every 2 days) or in combination with VP based low intensive chemotherapy (Vincristine/Prednisone) in our institution. Efficacy was assessed by complete remission (CR) rate, MRDneg (<0.01%) rate by multiparameter flow cytometry (MFC) and CMR (BCR-ABL1 transcript<10-5) rate by real-time quantitative polymerase chain reaction (RT-qPCR). Safety profiles were also monitored in this study. Results From December 2021 to June 2022, 10 Ph/BCR-ABL1+ ALL pts were treated with olverembatinib due to T315I mutation or disease recurrence, after prior TKIs combined with chemotherapy. Median age was 60.5 years (range, 37-65), and 6/10 were males. 5 pts had received 2 types of TKIs previously, of which 2 pts relapsed after ponatinib (Table 1). Among 10 pts, 6 were still in CR1 (pt 1-6), their T315I mutations were detected during regular follow-up. 4/6 pts were persistently molecular positive, while the other 2 had molecular relapse. Median time from diagnosis to the administration of olverembatinib was 5 months (range, 3-17). Among the 4 pts with hematologic relapse (pt 7-10), 2 (pt 7, 8) had T315I mutation. Because of the successive occurrence of G250E, Y253H, L248V mutations and L248 K274del, the 3rd one (pt 9) relapsed twice and failed to response to two kinds of TKIs and chemotherapy. As for the last pt (pt 10), although no ABL1 mutations were found, she was in 3rd relapse with CNS and BM involvement. Median time from diagnosis to the start of olverembatinib for these 4 relapsed pts was 28 months (range, 5-41). Among 6 pts with T315I mutation and persistent molecular diseases or molecular relapse, the CMR rate was 66.7%, with a median time of 3 months (range, 1-4) to achieve CMR. Then 2 pts underwent allo-HSCT (pt3, 4), who were still in CR. Among 4 hematological relapsed pts, the CR rate was 75%. 1 pt (pt8) with T315I was unresponsive, while another T315I positive patient achieved MRDneg by MFC after 1 month of treatment, with a complete disappearance of T315I mutation (pt7), though the BCR-ABL1 transcript was still positive. The remaining 2 relapsed pts without T315I mutation achieved hematologic CR after 1 month of olverembatinib monotherapy (pt9,10). Totally, overall response rate (ORR) was 70% and MRDneg rate by MFC was 71.4% (5/7), while the CMR rate by PCR was 57.1% (4/7). Notably, olverembatinib was ineffective in neither of the 2 pts who have been previously treated by ponatinib. Meanwhile, the olverembatinib-based therapy was well-tolerated, and the main adverse events of the third-generation TKIs, such as cytopenia, elevated transaminases, hypertension, and cardiovascular events, were less frequent than those reported relating to ponatinib. In addition, 4 patients developed grade 1 skin pigmentation (pt2,3,6,9). There were no drug-related death or permanent discontinuation due to toxicity. Conclusion This work suggests that Olverembatinib is a very promising 3rd-generation TKI. It is effective and safe in Chinese adult Ph/BCR-ABL1+ ALL with extremely poor prognosis, especially in T315I mutated or relapsed pts. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

An Observational Prospective Study of Dasatinib 50mg Daily As Frontline Therapy in Newly Diagnosed Chronic Myeloid Leukemia Patients in Chronic Phase

Study Title: An observational prospective study of Dasatinib 50mg Daily as Frontline Therapy in newly diagnosed Chronic Myeloid Leukemia patients in Chronic Phase Background: BCR-ABL Tyrosine kinase inhibitors (TKI's) are most successful of targeted therapies and are currently considered cornerstone in the management of patients with chronic myeloid leukemia (CML). TKIs approved for first line therapy in CML are Imatinib, Nilotinib, Dasatinib and Bosutinib. Data suggests that Dasatinib, a second generation TKI is 325 times more potent than Imatinib. [1, 2] A five-year follow-up of DASISION study showed that Dasatinib 100mg as a frontline lead to more rapid and deeper responses at early time points when compared with Imatinib, with estimated 5 years OS & PFS as 91% and 85%, also 5-year MMR rate as 76% respectively. [3] Talpaz. M. et al study showed that Dasatinib is active in lower dose and have better safety profile when evaluated as a second line treatment after Imatinib failure. [4] Naqvi et al. results showed that Dasatinib 50mg is active and well tolerated and also have the better 3- and 6-month rate of molecular response (BCR-ABL1 transcripts (IS) ≤1%) i.e., 72% and 84%, compared with 48% and 69% with Dasatinib 100mg, and 13% and 49% with imatinib 400mg, respectively. [5, 6]. Therefore, we aim to evaluate the molecular responses and safety of Dasatinib 50mg daily as a frontline therapy in Indian CML-CP patients. Material & Methods: It is an observational prospective study. All CML-CP patients started on Dasatinib 50mg daily will be offered to participate in this study. The data of demography, baseline characteristics, molecular response, toxicity, deaths, progression will be collected and the same will be entered in case record form/excel sheet. We retrospectively collected the data of Imatinib to compare the response outcome with lower dose dasatinib 50mg daily. Patients who received frontline dasatinib 50mg for less than 3 months for reasons other than toxic effects or intolerance to dasatinib were discontinued from the study. Informed consent form has been taken from patients who participated in the study. Objectives:To evaluate and compare the efficacy of lower dose dasatinib 50mg daily and Imatinib in Indian patients with CML-CP.To assess toxicities of lower dose dasatinib 50mg daily according to the CTCAE v 5.0 Results: Between June 2020 to Feb 2022, total 50 patients were included in the dasatinib 50mg once daily. Median age is 40 yrs. ranging from (19-73) yrs. Median spleen and liver size is 8cm (2 - 22) cm and 2cm (0 - 16.8) cm respectively. Duration of symptoms are 60 days (4 - 547) days. Median Hb, TLC and Platelets are 10.25gm/dL (5.1 - 14.9) gm/dL, 158980/cumm (30400 - 572880)/cumm and 327 × 109/L (83 - 789) × 109/L. Median time from diagnosis to treatment was 6 days (0 - 20) days. At a median follow up of 9.2 months, 49 patients completed 3 months and out of which 48 patients were evaluated as one patient stopped medication after a month due to financial constraint. The response rate at 3 months of lower dose of dasatinib 50mg daily and Imatinib were 68.75% and 69.7% respectively. At 12 months 68% and 66.6% patients achieved major molecular response [BCR-ABL≤0.1%] in dasatinib 50mg and imatinib group respectively. Dasatinib 50mg is showed somewhat similar profile in comparison to early molecular response [EMR], but patient on lower dose dasatinib achieved a good percentage of deep molecular response [MR4.0: BCR-ABL ≤ 0.01% and MR4.5: BCR-ABL ≤ 0.0032%] even at 6 months i.e., 05 (16.1%) and 02 (6.45%) respectively. Six (12%) patients switched to other TKI (Toxicity: 02 & Suboptimal Response/Failure: 04) and 10 (20%) of patients required dose escalation in view of suboptimal response/failure with low dose dasatinib 50mg daily group. Treatment was well tolerated in lower dose dasatinib 50mg daily group. Weight gain (04), Constipation (02), Thrombocytopenia (05), Elevated Liver Enzymes (02). Diarrhoea (03), Oral mucositis (01) and Skin Hypopigmentation (01) was observed in dasatinib 50mg daily group. All patients were alive in low dose dasatinib 50mg daily group whereas 2 patients expired in imatinib group and the cause is unknown. Conclusion: Lower dose dasatinib is safe and effective as an upfront therapy in CML-CP. Lower dose dasatinib showed faster and deeper molecular response as compared to Imatinib. Dasatinib, taken daily at a dose of 50 mg, may offer a new, cost-effective choice for frontline therapy in CML-CP. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Retrospective Study of Treatment Free Remission in Patients with Chronic Myeloid Leukaemia(CML) Treated at Tertiary Care Oncology Centre from India

Background Tyrosine kinase inhibitors (TKI) have dramatically improved outcomes in Chronic Myeloid Leukemia(CML) patients, but lifelong TKI therapy can negatively impact patients' quality of life due to chronic adverse events. Treatment free remission(TFR) is now the new goal of CML therapy. Studies have shown this is feasible in developed countries. Literature on discontinuation of TKI therapy in resource limited countries such as India is scarce. The purpose of this study was to investigate whether some chronic myeloid leukemia patients with excellent and sustained molecular responses to tyrosine kinase inhibitor treatment can gradually de-escalate TKI therapy and stop therapy in Indian setting. Methods We included all patients above the age of 18years with diagnosis of CML in first Chronic Phase (CP) on TKI therapy of minimum 3 years duration with major molecular response (MMR i.e., <0.1% BCR-ABL1 transcript) of minimum of 2 years duration, enrolled for treatment free remission between January 2018 to December 2021. Starting dose of imatinib was 400mg once daily, dasatinib 100mg once daily and nilotinib 300mg twice a day. In this study the dose of these drugs was reduced by 25% every 6 months . This dose reduction was done with 2 monthly outpatient clinic visits and 2 monthly BCR-ABL1 quantitative PCR monitoring. Patients who maintained MMR during 6 months of dose de-escalation qualified for next level of dose de-escalation. Eventually treatment was stopped completely and monitoring continued. This was retrospective medical record based study done at a tertiary care centre in North India. Results Between Jan 2018 to Dec 2021, 29 patients were enrolled for dose de-escalation and treatment cessation. Among these 29 patients, 19 were on imatinib, 2 on dasatinib and 8 patients on nilotinib. Median age was 39 years( range 21 years to 67 years). Twelve patients were male and 17 female. Median duration of TKI therapy prior to de-escalation was 8 years (range 4years-14 years). Median duration of major molecular response prior to dose reduction was 6 years( range 3years-12 years). In our study 17 of 29 patients had an outcome, while 12 patients are still on de-escalation phase with maintained MMR and are not included in the outcome analysis. Eight patient had loss of MMR(47.05%), 6 while on dose de-escalation and 2 after cessation of TKI. All eight patients achieved MMR after re-initiation of the prior dose, out of these 6 patients had sustained MMR(>6months) at reduced TKI dosing compared to conventional dose. Nine patients (52.9%) have successfully stopped TKI for median duration of 11months (range 6 to 19 months). Conclusion TKI de-escalation was safe for most patients with excellent prior response to TKI therapy. This way of dose reduction , ensured motivation and commitment of patients by doing regular OPD follow ups and BCR-ABL1 PCR testing. In our study 52.9% patient could successfully maintain TFR at a median follow up of 11 months of stopping the drug. We also identified that a subgroup of patients(35.29%) who were unsuccessful in complete cessation of therapy but maintained their molecular response at reduce dose of TKI . These findings show that lower TKI doses might maintain molecular responses in these patients, implying that such patients could be overtreated with routine dosing. More studies of dose de-escalation are warranted.

Economic Impact Analysis of Treatment-Free Remission in Chronic Myeloid Leukemia Patients with Sustained Deep Molecular Response in the AST-2018 Trial

Introduction: The introduction of tyrosine kinase inhibitors (TKIs) has revolutionized the treatment of chronic myeloid leukemia (CML), bringing the life expectancy of patients close to that of the general population. However, TKI treatment is associated with adverse events, some of them serious or affecting quality of life. In addition, drug costs have a high economic impact, especially in low-income countries. Treatment-free remission (TFR) is an emerging goal for CML patients and it has been associated with cost savings in different country analyses. Main Objective: Assess the economic impact of TKI discontinuation in patients included in the AST2018 Trial. Secondary objective: Estimate the long-term saving in patients included in the AST2018 Trial, considering Argentinian life expectancy. Methods: AST2018 is a multicentric, prospective trial that recruited aged >18 years CML chronic phase patients, with confirmed typical BCR-ABL1 transcripts b3a2 and/or b2a2, under TKI treatment for at least ≥ 4 years and sustained MR4.0 for ≥ 2 years. Molecular tests were centralized in 2 harmonized laboratories and performed monthly for the first 6 months, every 2 months until the 1st year, and every 3 months until month 24. TKI was restarted at confirmed loss of major molecular response (MMR). The economic impact was evaluated by an Excel-based budget impact model, in order to estimate the costs of the patients in first-line pharmacological treatment for CML. We considered the costs of TKI-treatment, PCRs performing and medical visits as money flow. We calculated the present value of savings, in US dollars, in patients who discontinued treatment during the trial. Results: Between February 2018 and March 2022, we evaluated 50 CML patients in the AST2018 trial, 46 were enrolled from 7 centers in Argentina, and were included in this economic analysis. The median patients’ age was 57.5 years (24-85). TKI treatment before discontinuation was Imatinib 34/46 (74%), Nilotinib 4/46 (9%) and Dasatinib 8/46 (17%). After 24 months since first patient was enrolled, 30/46 (65%) patients continued free from TKI, Imatinib 21/34, Nilotinib 2/4 and Dasatinib 7/8, with a median follow-up of 31.3 months (range 25.9 - 38.1). Treatment was restarted after losing MMR in 16/46 (35%) patients. We considered the costs of TKI treatment, PCR performing and physician visits, and we calculated the estimated cost saving per patient at 24 months on TFR: Imatinib US$ 78,433; Dasatinib US$ 102,817 and Nilotinib US $106,161. For the 30 patients who persisted in TFR for 24 months, total cost saving was US$ 2,579,137. For 17 patients who lost MMR, US$ 335,043 dollars were saved previously to TKI reinitiation. Adding up both amounts, the total economic saving in AST2018 was US$ 2,914,181. We performed an analysis of the potential cost savings of remaining in TFR beyond 24 months and according to life expectancy in Argentina (76 years), median age of patients in this trial and cost per patient/year on TKI treatment, the estimated cost saving per patient was US$ 714,512. Conclusions: This is the first economic analysis of the AST2018 trial on TKI discontinuation in CML patients with sustained deep molecular response in Argentina. Our analysis shows that, in spite of the PCR spending, there is a considerable saving in patients on TFR. A careful approach for patients participating in TFR trials or programs will decrease the risk of relapse and make TFR a reality in our region. Potential advantages of TFR will not only impact in patients’ quality of life but also show considerable reduction in the use of economic resources. In developing countries, where lack of molecular monitoring is still an issue outside academic centers, these savings could be redirected to this unmet need making TFR feasible and a goal for the patient and the healthcare system. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Do Adult Philadelphia-Positive Acute Lymphoblastic Leukemia (Ph+ ALL) Patients Require Allogeneic Transplant in First Remission (CR1)?

Introduction: Ph+ ALL has long been considered a high risk leukemia with poor outcomes when multi-agent chemotherapy is used alone. Allogeneic transplantation is considered by many the only chance of cure in this population. After reviewing data at Princess Margaret Cancer Centre (PMCC) in 2016, we found no overall survival (OS) difference between transplanted and non-transplanted Ph+ ALL patients. Thereafter, only relapsed or refractory patients were transplanted. We sought to determine the outcomes of non-transplanted Ph+ ALL patients who received a modified pediatric regimen (without asparaginase) with imatinib. Methods: A retrospective chart review of Ph+ ALL treated at PMCC from 2001 to 2019 was undertaken. Patient demographic data, disease characteristics, response, and course, as well as treatment information, were collected and a descriptive summary was presented using counts/proportions and median/IQR or range as appropriate. OS/RFS rates were calculated using the Kaplan-Meier product-limit method, and the impact of covariates of interest were assessed using the Log-rank test. Results: 158 Ph+ ALL patients were identified since 2001. 56 patients (35.4%) received a transplant in CR1, while 102 (64.6%) did not. All patients received a modified pediatric-inspired regimen typically with imatinib (Table 1). Median follow up was 38 months (range 1 to 229 months). 144/158 patients achieved a CR with first induction (91%). N=6 patients died during induction (3.8%). Overall survival for all patients at 3 and 4 years, was 61.8% (95% CI 53.4-69.1%) and 54.1% (95% CI 45.5-61.9%) respectively. Overall RFS at 3 and 4 years, was 51.7% (95% CI 43.3-59.4%) and 46.3% (95% CI 37.9-54.2%) respectively. When stratified by transplant in CR1, 3-year OS was 49.8% (95% CI 36.1-62.0%) in transplanted patients vs 69.2% (95% CI 49.3-69.9%) in non-transplanted patients; p=0.145 (Figure 1). There was no significant difference in RFS at 3 years in transplanted (46.4% [95% CI 33.0-58.7%]) vs non-transplanted (55% [95% CI 44.2-64.6%]) patients; p=0.89. A 6-month PCR level indicating a molecular 3 log (or deeper) reduction (MR3) in BCR-ABL1 transcripts predicted a statistically significant improved 3-year RFS of 71.4% (95% CI 40.6-88.2%) vs those who had achieved only an MR2 (25% [95% CI 0.9%-66.5%] p=0.037). Overall, 48 patients relapsed. Of these, 13 received blinatumomab +/- a tyrosine kinase inhibitor (TKI) after relapse and 12/13 (92.3%) achieved a second CR, including one patient who had relapsed post-transplant. Of the 12 who achieved a CR2, 5 went on to an allogeneic transplant. Conclusion: Using a modified pediatric regimen and imatinib, there was no difference in overall survival between transplanted and non-transplanted Ph+ ALL patients, provided that they achieved an MR3 (or deeper) at 6 months. In those who were not transplanted in CR1 and subsequently relapsed, blinatumomab + TKI was a successful salvage regimen. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Comparison of Generic Dasatinib Versus Imatinib in Newly Diagnosed Chronic Phase Chronic Myeloid Leukemia with Reference to Early Molecular Response: Results from a Single-Center, Randomized Controlled Study from India

Background: Chronic myeloid leukemia (CML) is the commonest leukemia in adult population in India. The advent of tyrosine kinase inhibitors (TKI) targeting BCR-ABL1 fusion transcript in CML has dramatically improved survival of CML patients. Generic formulations of imatinib mesylate have been the mainstay of TKI therapy in Indian CML patients for more than a decade, due to prohibitive costs of 2nd generation TKIs and poor socio-economic status of majority of patients. However, with the availability of generic dasatinib in India since March 2021, the cost of dasatinib therapy has become comparable to that of generic imatinib treatment, thereby enabling more extensive use of dasatinib as first-line TKI therapy in CML patients in India. Achievement of early molecular response (EMR) after 3 months of first-line TKI therapy, defined as blood BCR-ABL1 transcript level ≤ 10% [international scale (IS)], has emerged as an important predictor of favorable long-term outcome in CML-CP. There is scarcity of data on efficacy & safety of generic formulations of dasatinib vis-à-vis generic imatinib in CML-CP patients in India, which the present study has attempted to explore at a tertiary care hospital in India. Objectives: The objectives of the study were to compare early molecular response (EMR) [defined as BCR-ABL1 transcript level ≤ 10%, I.S.] at 3 months of therapy with generic dasatinib versus generic imatinib in newly diagnosed CML-CP patients and to compare treatment-related adverse effects in the two groups. Methods: This randomized controlled study enrolled newly diagnosed CML-CP patients after obtaining institutional ethics committee approval & informed consent. Inclusion Criteria:Newly diagnosed patients with chronic phase CML.Age ≥ 12 years. Exclusion Criteria:Patients with de novo accelerated phase or blast phase CML.Pregnancy & lactation.Patients with pre-existing pleural effusion, grade ≥ 3 lung disease, or pulmonary arterial hypertension.Patients with angina, or grade ≥ 3 cardiac disease [as defined by the New York Heart Association (NYHA) criteria] at diagnosis.Patients with prolonged QTc interval (> 480 msec) at baseline. The EUTOS long-term survival (ELTS) risk score was calculated at diagnosis. Patients were randomized to one of the two following treatment groups: Group A: Dasatinib 100 mg p.o. once daily (60 mg/m2/day for age <18 years). Group B: Imatinib 400 mg p.o. once daily (340 mg/m2/day for age < 18 years). Follow up & monitoring of patients was done every 2 weekly till completion of 3 months of TKI therapy, followed by assessment of hematological response & molecular response as per standard criteria. Results: A total of 61 consecutive CML patients were screened between June 2021 and March 2022, out of which 54 patients with confirmed diagnosis of CML-CP were enrolled in the study and were randomized to receive generic dasatinib or generic imatinib as first-line therapy and were followed up for 3 months for EMR and complete hematological response (CHR). Four patients were lost to follow up and data was analyzed for 50 patients for whom EMR results at 3 months was available. Out of these 50 patients, 24 patients received dasatinib & 26 patients received imatinib. The median age of patients was 33 years (range 18-64 years), with male: female ratio of 1.3: 1. Achievement of CHR was documented in 96% of patients in both dasatinib & imatinib treatment arms. EMR at 3 months was achieved in overall 72% patients in study [19/24 patients (79%) in dasatinib arm & 17/26 patients (65%) in imatinib arm]. However, the difference was not statistically significant (p = 0.27). Notably, EMR rates in ELTS intermediate-risk group was 86% in dasatinib arm versus 42% in imatinib arm, and EMR rates in ELTS high-risk group was 82% in dasatinib arm versus 57% in imatinib arm (p = 0.33). The incidence of grade 3-4 adverse events was not significantly different in the two treatment groups. The patient characteristics & treatment results are summarized in Table 1 & Figure 1. Conclusion: The results of the present study suggested that generic formulations of dasatinib were well-tolerated and were associated with improved early molecular response rates compared to generic imatinib in CML-CP patients in India. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Chip-Based Digital PCR Platform, Lab on an Array, the Newly Developed Highly Accurate and Sensitive Method for the Detection of BCR-ABL1 Transcripts in Chronic Myeloid Leukemia

Introduction: With the development of various BCR-ABL1 tyrosine kinase inhibitors (TKIs), chronic myeloid leukemia (CML) has become a manageable hematologic malignancy and current therapeutic goal is treatment free remission (TFR). To achieve a successful TFR in more patients, a precise assessment of minimal residual disease (MRD) has become one of the prerequisite requirements. Since undetectable BCR-ABL1 by conventional TaqmanTM-based quantitative polymerase chain reaction (qPCR) is not an indicator for complete eradication of CML clone, more precise methods should be developed. Currently, to overcome some limitations of conventional qPCR, such as rigorous standardization process and various sensitivity between laboratories, digital quantitative-PCR (dqPCR) methods such as nanofluidic or droplet dqPCR have been developed for accurate and precise detection of various genes and its use in the routine clinical practice is gradually expanding. However, current dqPCR methods may have limitations due to partition-based amplification and end-point interpretation. Therefore the establishment of clinical guideline is crucial for wide application on TFR in CML. Therefore, we have developed a novel technology, a chip-based real-time dqPCR platform (LOAA; Lab On An Array; so called Dr. PCR™) to achieve more stable, accurate and precise monitoring of BCR-ABL1 in a timely manner. Methods: To assess the equivalence between Dr. PCR and conventional qPCR, we evaluate the efficacy of BCR-ABL1 detection using cell lines and clinical specimens. For linearity assessment, we used BCR-ABL1 positive (e14a2) K562 cell line diluted to 9 points by 10-fold serial dilutions from 100 to 10-8 with BCR-ABL1 negative HL60 cells. With the results from cell lines, we also evaluated linearities for both e13a2 and e14a2 major BCR-ABL transcripts using 7 clinical specimens obtained from Leukemia Omics Research Institute of Eulji University. In detail, conventional qPCR was performed using Transcriptor First Strand cDNA Synthesis Kit (Roche, USA) for cDNA synthesis and Real-Q BCR-ABL Quantification Kit (Biosewoom, South Korea) for qPCR. Total 800ng of RNA per test was used for qPCR (QS5, Thermo Fisher, USA) with 8 replicates and duplicate for cell line and clinical specimens, respectively. For Dr. PCR (1-step reverse transcriptase PCR), 400ng (for cell lines) or 500ng (for clinical specimens) of RNA per test was applied to disposable cartridges of Dr. PCR™ BCR-ABL1 Major IS detection kit (Optolane Technologies, South Korea) with LOAA platform (Optolane Technologies, Korea). The copies of BCR-ABL1 and ABL1 were analyzed by LOAA analyzer S/W (Optolane Technologies, South Korea). Based on the results, correlation analysis between qPCR and Dr PCR was performed using correlation graphs and Blend-Altman plots. Results: Correlation analysis for cell line dilution assay showed that measured values from both qPCR and Dr. PCR were closely correlated with the R2 of 0.984. LOA95 (limit of agreement at 95% confidence interval) analyzed by Blend-Altman plot was -0.711 ~ 0.303 (mean = 0.02), indicating the two methods are closely correlated (Figure 1). The linearity assessment for e13a2 and e14a2 sub-genotypes using primary cells from 7 clinical specimens of CML patients again showed a close correlation with the R2 of 0.984 and 0.985, respectively. LOA95 values were -0.516 to 0.384 (mean = -0.066) and -0.407 to 0.361 (mean = -0.023), respectively. Interestingly, Dr PCR efficiently detected clinical specimens with low copy number of BCR-ABL1 compared to conventional qPCR, which is beneficial for the determination of MDR levels in patients especially those who are required to monitoring after cessation of TKIs. Comparison between conventional qPCR, droplet dqPCR and Dr PCR is listed (Table 1). Results with more specimens from CML patients and additional information will be updated at ASH presentation. Conclusion: Taken together, we believe our novel chip-based real-time dqPCR (Dr. PCR™) may minimize false positive results and maximize the analytical sensitivity of detecting BCR-ABL1 fusion transcripts and thus, would be useful for the selection of therapeutic option in routine clinical practice and TFR. We will include the result for further intensive study using more clinical specimens including samples of low copy number of BCR-ABL1. Study support: Funded by Korea Research FoundationFigure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Emergence of Chronic Myeloid Leukemia in Patients with Myeloproliferative Neoplasms: A Single-Institution Experience

Introduction: Chronic myeloid leukemia (CML) is characterized by the presence of the BCR-ABL1 translocation and is typically distinct from other myeloproliferative neoplasms (MPN) including polycythemia vera (PV), essential thrombocythemia (ET) and myelofibrosis (MF). Concurrent diagnosis of CML and MF is uncommon and infrequently described in case reports.1 Moreover, very few cases have been described of CML occurring after an established diagnosis of MPN.2-3 Due to the rarity of concurrent CML and MPN, management strategies in this population are not defined. In addition, the latency time from the emergence of BCR-ABL1 positive clones to a clinical diagnosis of CML in this setting is largely unknown. To address these questions, we interrogated our institutional experience and retrospectively analyzed available specimens. Methods: We collected information on patients seen at Massachusetts General Hospital (MGH) from January 1 2012 to January 1 2022 for CML occurring after an established diagnosis of MPN. Available stored samples were retrospectively tested for BCR-ABL1 with a fusion transcript assay (MGH Center for Integrated Diagnostics, Boston, MA). Results: We identified four patients with CML preceded by MPN (Table 1). Three patients had prior MF, diagnosed 4.3-7.6 years before the onset of CML; two of these had post-ET MF. Patient #4 had ET diagnosed 4 years prior to onset of CML, then went on to develop MF 4.9 years after CML diagnosis. None of the patients were on JAK inhibitors, hydroxyurea or interferon at the time of CML diagnosis. All patients had a leukocytosis with characteristic features on the differential prompting evaluation for CML. The median white blood cell count was 45.83 x 10^9/L (range 27.49-121.02). All four patients had an elevated basophil count (median 2.99 x 10^9/L, range 1.1-22.99) and two had an elevated eosinophil count (median 1.11 x 10^9/L, range 0.55-44.17). Regarding MPN driver mutations, one patient had a JAK2 V617F, one patient had a CALR exon 9 deletion, and two patients had no identifiable mutations on extended next-generation sequencing. For CML treatment, three patients received dasatinib (two with 100 mg daily, one with 50 mg daily), whereas one received nilotinib (150 mg twice daily). Two achieved a major molecular response (MMR) (at 7 and 8 months); one had an early molecular response at 6 months (last follow-up); one (with e13-a3 transcript) could not be quantified on a standard PCR assay but achieved a complete cytogenetic response by 4 months. At the time of last follow-up, two patients were in MMR on tyrosine kinase inhibitors (TKI), whereas two underwent allogeneic hematopoietic cell transplantation (alloHCT), primarily for progression of MF. We retrospectively interrogated available samples for evidence of the BCR-ABL1 translocation prior to a clinical diagnosis of CML. Patient #2 was followed at MGH for MF and thus had available samples. We identified BCR-ABL1 transcripts in the peripheral blood three months prior to his clinical diagnosis of CML (unable to be quantified due to e13-a3 transcript); there were no available samples from earlier in his disease course for testing (Figure 1). Discussion: CML can emerge in patients with MPN. Herein, we describe four cases of this phenomenon. Signs of CML evolution included marked leukocytosis, as well as basophilia and eosinophilia. Despite underlying MF, three patients tolerated full-dose TKI and achieved molecular responses early in their disease course. However, MPN progression remained a significant challenge, with two patients ultimately requiring an alloHCT. Of note, we found evidence of BCR-ABL1 in the peripheral blood three months prior to clinically apparent CML in one patient. Experiments using single cell techniques in patients with concurrent MPN and CML would provide insights into the clonal architecture and are in planning stages.

First-in-Human Study of Elvn-001, a Highly Selective BCR::ABL1 Tyrosine Kinase Inhibitor, in Patients with Chronic Myeloid Leukemia Who Failed Previous Tyrosine Kinase Inhibitor Therapies

Background: Despite the benefits BCR::ABL1 tyrosine kinase inhibitors (TKIs) have provided altering the natural history of chronic myeloid leukemia (CML), resistance/lack of response and intolerability occurs. ELVN-001 is a highly selective small molecule active site inhibitor of ABL1 that does not significantly inhibit the receptor tyrosine kinases PDGFR, KIT, VEGFR2 or the Src-family (eg SRC, LCK, LYN, FYN). In vitro data also supports ELVN-001 targeting the most common CML mutation, T315I and not being a substrate for drug efflux transporters such as BCRP, which may contribute to resistance or sensitivity to other TKIs. Non-clinical data suggests ELVN-001 has a favorable absorption, distribution, metabolism, elimination and a pharmacokinetic (PK) profile supporting once daily (QD) dosing, low risk of QTc prolongation, and potential to avoid drug-drug interactions, particularly CYP-mediated. This first-in-human (FIH) study will evaluate the safety, tolerability, PK and preliminary anti-CML activity of ELVN-001 in patients (pts) with chronic (CP) or accelerated phase CML with and without T315I mutations. Objectives: The primary objectives are to determine the recommended doses for expansion (RDE) and to evaluate the safety and tolerability of ELVN-001. Secondary objectives are to assess the PK profile and preliminary efficacy. Design: A phase 1 open-label, multi-center, dose escalation and expansion study. Eligible pts are adults with CP and AP CML who are intolerant or have failed (as per ELN 2020 Recommendations) available TKIs known to be active for treatment of their CML. Other key eligibility criteria are Eastern Cooperative Oncology Group performance status 0-2, adequate bone marrow, renal and liver function, and resolved adverse effects of prior therapy. Prior marrow transplant is allowed. CML with point mutations E255, Y253, G250, F317 or Q252 are excluded. Successive cohorts will receive escalating doses of ELVN-001 starting at 10 mg QD. Dosing will be continuous in 28-day cycles until treatment failure, disease progression or unacceptable toxicity. A standard 3+3 dose escalation will be used, with PK/pharmacodynamic modeling to identify the RDEs, assuming toxicity is not dose limiting. Safety and efficacy of ELVN-001 will be further explored in CP-CML without T315I mutations and a cohort of T315I mutated CP-CML. Mutational analyses by Sanger and NGS will be conducted at baseline and end of treatment. Main Outcomes: Primary endpoints are dose limiting toxicities, adverse events, laboratory and ECG abnormalities. Secondary endpoints are PK parameters, response based on BCR-ABL transcript levels by quantitative PCR and hematology. Conclusions: This FIH study will evaluate dosing, safety, tolerability, PK profile and preliminary efficacy of ELVN-001 in CP-CML with and without T315I mutation. Study sponsor: Enliven Therapeutics. NCT05304377 ELVN-001-101 Schema: Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Clonal Evolution of t(8;21) Coexisting with t(9;22) in a Blastic Transformation of Chronic Myeloid Leukemia

Abstract Introduction/Objective Chronic myeloid leukemia (CML) is a myeloproliferative disorder characterized by chromosomal translocation t(9;22) and the production of the fusion protein BCR-ABL1. The clinical course of the disease is characterized by a chronic phase, accelerated phase, and blast phase. One of the criteria for the progress of chronic phase to accelerated phase is the presence of cytogenetic anomaly additional to t(9;22). The blast phase of CML usually presents as acute myelogenous leukemia (AML); however, its characteristics are different from de novo AML. One of the most common subtypes of de novo AML with balanced translocation is AML with t(8;21). Here, we present a case of the blast phase of CML that presents t(8;21). Methods/Case Report The peripheral blood from a 51-years-old-man presenting with fatigue and splenomegaly showed leukocytosis, mild anemia, marked neutrophilia with left shift, monocytosis, basophilia, and &amp;lt;1% blasts. Flow cytometry identified an increase in granulocyte events with the left shift. Chromosome studies detected t(9;22) by karyotyping and FISH. BCR-ABL1 transcript was detected at 41.98% on the International Scale by RT-PCR, consistent with chronic myeloid leukemia (CML). The following bone marrow biopsy confirmed a diagnosis of the chronic phase of CML with &amp;lt;5% myeloblasts. After a year of treatment with imatinib, the patient developed marked leukocytosis, anemia, and thrombocytopenia. Flow cytometry detected an immature cell population comprising ~50% of total cells positive for CD117, CD34 (partial), CD13 (dim), and CD33. A few blasts were also positive for cMPO and negative for CD14, CD64, TdT, Glycophorin A, cytoplasmic CD3, CD19, and other markers. BCR-ABL1 transcript was detected at 56.45% on the International Scale by RT-PCR. Chromosome analysis revealed all cells (20/20) exhibiting t(8;21) leading to a fusion between RUNX1 and RUNX1T1 genes with a maintained t(9;22). FISH analysis confirmed t(8;21) and t(9;22). These findings were consistent with a blast phase of CML. Results (if a Case Study enter NA) NA Conclusion Progression of CML is frequently accompanied by cytogenetic evolution. However, the development of t(8;21) in Ph+ clones is extremely rare. Only six cases have been previously reported. Misidentifying this blast phase of CML (in the absence of a clinical history of the chronic phase of CML) as AML with recurrent genetic abnormalities is a potential pitfall we should be aware of.

MPN-196 Unusual Association Case of Janus Kinase 2 Mutation and BCR-ABL Transcripts: Successful Treatment With Hydroxyurea

It is well known that mutations (like JAK2) are mutually exclusive events in myeloproliferative neoplasms (MPN). The presence of mutations (like JAK2) is seen in BCR-ABL1-negative MPN, but its presence with chronic myeloid leukemia (CML) is a rare finding; only a few cases have been reported (1). In this case, we describe patients who had both mutations (BCR-ABL and JAK2 V617F). We present the case of a 37-year-old man referred to our clinical department in 2017 for thrombocytosis. He had a history of arterial hypertension, was a chronic smoker and occasional alcoholic, and had a right fifth toe amputation in 2013. We discovered an asthenic patient with no splenomegaly and amputation of the third toe on the right foot on clinical examination. A complete blood count revealed that the patient was thrombocythemic (platelet [PL] counts of 1,783,000/mm3), had neutrophil leukocytosis (21,300/L), and had a hemoglobin level of 12 g/L. JAK2 V617 mutation was positive, and transcript BCR-ABL (M-bcr) was found by RT-PCR quantification to be 0.082%. However, karyotype analysis revealed that he was 46 years old, XY. His bone marrow was hypercellular with an increased number of megakaryocytes. The patient was followed in the cardiovascular department for his microangiopathy, which resulted in a second amputation of the right third toe in 2017. When he did not achieve complete hematological remission after one month on imatinib mesylate 400 mg daily, the dose was increased to 600 mg/J. Due to treatment failure with PL counts around 100,000 after 6 months, the treatment was changed to hydroxyurea (1 g/J) and imatinib was discontinued. The patient had been in complete hematologic remission for the previous 3 years. Several cases of concomitant JAK2 myeloproliferative disorders and BCR-ABL transcript have been reported. This hybrid disease is more likely to be misdiagnosed because it is underdiagnosed. Patients with association had a poor response to imatinib (3), which was also the case in our patient, who had a good hematological response to hydroxyurea but a poor response to imatinib.

CLINICAL AND MOLECULAR REPORT OF A RARE RAM POSITIVE NON-DOWN SYNDROME INFANT CBFA2T3-GLIS2 NEGATIVE, PRESENTING THE DRIVER P210-BCR-ABL1

Pediatric Acute Megakaryoblastic Leukemia (AMKL) comprises 4%‒15% of Acute Myeloid Leukemia (AML) cases. Down Syndrome (DS)-AMKL usually displays a favorable outcome, whereas the prognosis of non-DS-AMKL is generally poor. Here we present the clinical and genomic data of a rare non-DS-AMKL infant with p210-BCR-ABL1 fusion, co-occurring with a high-risk WT1 mutation. The baby was RAM positive and CBFA2T3-GLIS2 negative, showing refractoriness to treatment. A 1-year-old girl was referred to the Hospital with a history of fever and motor developmental delay for four months. On admission, she presented ecchymosis, swelling, and organomegaly (spleen and liver). The WBC count was 26.5 × 10 3 /μL, hemoglobin level was 7.6 g/dL, platelet count was 25 × 10 3 /μL, and LDH was 2.887. At diagnosis, she showed bilateral myeloid sarcoma. Morphological analysis of the Bone Marrow (BM) showed clustered cytoplasmic blebs. Flow cytometry analysis revealed 83% of blast cells and a profile compatible with AMKL and RAM phenotype. The patient was treated under the high-risk AML-BFM-2004. Imatinib was incorporated into the treatment after BCR-ABL1 detection. However, minimal residual disease remained positive throughout the treatment, making BM transplantation unfeasible. Disease refractoriness was persistent even with the administration of Dasatinib, FLAG-IDA and Venetoclax. The patient died one year after diagnosis due to sepsis during BM aplasia. We performed G-banding, FISH, and Multiplex RT-PCR experiments. The molecular response was assessed by absolute quantification via RT-qPCR assays. Sanger sequencing and NGS were performed on a targeted approach. The karyotype was 46,XX,t(9;22)(q21;q34). We observed polyploidy (3‒20N). FISH in polyploid Nuclei (8N) showed four BCR-ABL1 fusion signals. In diploid metaphases, we observed two BCR-ABL1 signals. Multiplex RT-PCR detected the p210- BCR - ABL1 . RT-qPCR monitoring detected persistent high levels of BCR-ABL1 transcripts associated with disease refractoriness. Sanger sequencing showed no GATA1 mutation. NGS revealed a missense WT1 pathogenic mutation, and CBFA2T3-GLIS2 was not present. RAM phenotype is characterized by overexpression of CD56 and under-expression of CD38, CD45, and HLA-DR. This phenotype is characteristic of children, usually associated with AML-M7 (38%) and intermediate-risk cytogenetics not associated with prognostic subgroups. RAM is related to a poor prognosis with high MRD and induction failure rates compared to non-RAM patients. This phenotype is associated with the CBFA2T3-GLIS2 fusion, which is related to extramedullary involvement, a particular blast morphology, and a worse outcome as compared to fusion-negative AML pediatric patients, including a high frequency of disease refractoriness and relapse. NGS studies did not show CBFA2T3-GLIS2 in our patient. Thus, our results indicate that RAM+ associated with the driver p210-BCR-ABL1, even with specific targeted therapy, may lead to treatment resistance regardless of CBFA2T3-GLIS2+. Here we highlight for the first time the presence of p210-BCR-ABL1 associated with RAM phenotype in the absence of CBFA2T3-GLIS2 and disease refractoriness in a non-DS-AMKL infant.

CML-057 State-of-the-Art Management of Chronic Myeloid Leukemia in the Emerging Regions

Chronic myeloid leukemia (CML) is characterized by a relapsing evolution, increased disease burden and poor prognosis in the advanced phases. The assessment of diagnosis and management options of CML in the Republic of Moldova. We performed the case-control study of 134 CML patients, who were treated and followed up at the comprehensive cancer center - Institute of Oncology between 2007-2022. The real-time PCR was used with the aim to determine the expression of BCR-ABL p210 and p190 transcripts while proceeding CML diagnosis. The study was related to the outpatient and hospitalized care. The patients' age ranged between 14-81 years. The median age was 51.4 ± 2.13 years. There were 78 (58.2%) males and 56 (41.8%) females. Tyrosine kinase inhibitors (TKIs) were supplied by The Max Foundation via Max Access Solutions (MAS). Imatinib, nilotinib, and ponatinib were used as a front-line therapy in newly diagnosed CML patients and in the cases of resistance to non-TKIs treatment. Complete response (CR) rate estimated the short-term results of chemotherapy, and the overall survival (OS) -long-term results. CML was diagnosed in chronic phase in 122 (91,04 ± 2.32%) patients. The rate of Ph-positive bone marrow (BM) cells ranged between 20 - 100%. In 72.7% of cases Ph-chromosome was detected in over 70% of the BM cells. BCR-ABL p210 transcript range was 21.84-100%. In 69.8% of cases BCR-ABL transcripts were identified in over 65% of the peripheral blood cells. Under the TKIs therapy the hematologic CR was achieved in 92.8% of cases, and the molecular CR - in 28.5%. One- and 5-year OS of patients treated with TKIs was 98.5% and 91%. IFN a-2b was used with partial response in cases of resistance to conventional chemotherapy (CC) and TKIs. In 79% of patients treated initially with CC, only the minor cytogenetic response was obtained. MAS program may be considered an efficient and transparent management option to ensure CML patients with potentially curable TKIs medication in the emerging regions regardless the age, gender, and social categories. The Max Foundation delivers TKIs medication to CML patients on a regular basis, accelerating health equity in low-and middle-income countries.

Mixed-Lineage Leukemia

Introduction: Acute Leukemia with Mixed Lineage phenotype (MLL) is leukemia that consists of cells characterized by mixed lineage markers, both from myeloid and lymphoid cells. The incidence of this leukemia is only 2-5% of all acute leukemias and is considered to have a poor prognosis.Case Presentation: A seven-year-old girl was diagnosed with MLL. The results of immunophenotyping showed two blast populations with the expressions of CD33, CD34, HLA-DR, CD117, CD13, CD19, CD10, CD20, CyMPO, Cy CD79a, and morphological features of Acute Lymphoblastic Leukemia (ALL) and Acute nonLymphocytic Leukemia (AnLL) on bone marrow aspiration. The BCR-ABL examination showed the detected BCR-ABL p210 (Major breakpoint), the majority of which was found in chronic myeloid leukemia (CML) patients. There is no definite pathogenesis of BCR-ABL p210 (MBCR-ABL) in this patient. BCR-ABL can also present in 11–29% of ALL patients but is relatively rare in childhood ALL (1%–3%) and mostly expresses p190 (minor breakpoint (mBCR-ABL)). The p210 BCR-ABL transcript is detected in 30% of adults and 20% of childhood ALL patients with Philadelphia ALL. Conclusions: MLL with BCR-ABL p210 transcript is very rare in acute leukemia. Immunophenotyping tests can detect typical MLL profiles, and WHO has standardized the diagnosis for MLL.

Deep molecular response in patients with chronic phase chronic myeloid leukemia treated with the plasminogen activator inhibitor-1 inhibitor TM5614 combined with a tyrosine kinase inhibitor.

We recently showed that pharmacological inhibition of plasminogen activator inhibitor-1 (PAI-1) activity, based on TM5614, increases cell motility and induces the detachment of hematopoietic stem cells from their niches. In this TM5614 phase II clinical trial, we investigated whether the combination of a PAI-1 inhibitor and tyrosine kinase inhibitors (TKIs) would induce a deep molecular response (DMR) in patients affected by chronic myeloid leukemia (CML) by quantifying BCR-ABL1 transcripts. Patients with chronic phase CML treated with a stable daily dose of TKIs for at least 1year and yielding a major molecular response (MMR) but not achieving MR4.5 were eligible for this study. After inclusion, patients began to receive TM5614 as well as a TKI. The primary objective was an evaluation of the cumulative incidence of patient progression from an MMR/MR4 to MR4.5 by 12 months. Thirty-three patients were enrolled in the study. The median age was 59.0 years and 58% were male. No Sokal high-risk patients were enrolled in this trial. The median TKI treatment duration was 4.8 years. At the start of this study, seven patients and 26 patients received imatinib and second-generation TKIs, respectively. The cumulative MR4.5 incidence by 12 months was 33.3% (95% confidence interval, 18.0%-51.8%). The cumulative MR4.5 spontaneous conversion over 12 months was estimated as 8% with TKIs alone based on historical controls. The halving time of BCR-ABL1 at 2months was significantly shorter for patients who achieved an MR4.5 , by 12 months than for the other patients (cutoff value: 48 days; sensitivity: 0.80; specificity: 0.91; ROC-AUC: 0.83). During this study, bleeding events and abnormal coagulation related to the drug were not reported, and TM5614 was found to be highly safe. TM5614 combined with TKI was well tolerated and induced MR4.5 in more patients than stand-alone TKI treatment.

Three atypical BCR/ABL transcripts detected simultaneously in a Philadelphia-positive acute lymphoblastic leukemia patient showing resistance to tyrosine kinase inhibitors.

The Philadelphia (Ph) chromosome with a BCR/ABL fusion gene is a characteristic feature ofchronic myeloid leukemia (CML) and partial acute lymphoblastic leukemia (ALL) patients, with different breakpoints of the BCR and ABL genes. Here, we report the case of a Ph-positive ALL patient with poor prognosis in whom simultaneous different BCR/ABL transcripts named e1a3, e1a4, and e1a5 were detected by RNA-seq analysis but not traditional RT-PCR. To our knowledge, this is the first report to describe coexistence of different atypical BCR-ABL transcripts in the same patient and that traditional TKI therapy may not overcome the poor prognosis. This finding will bring new challenges in diagnosis and monitoring for minimal residual disease.