Real-world Imatinib Mesylate Treatment in Patients with Chronic Myeloid Leukemia: The Importance of Molecular Monitoring and the Early Molecular Response.

INTRODUCTION: Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder characterized by the Philadelphia (Ph) chromosome. After the introduction of imatinib mesylate (IM) in 2000, the natural history of the disease changed. Data on the treatment of CML with IM are from randomized clinical trials. Establishing whether these results can be reproduced or if caution is needed when extrapolating data to the general population with CML is essential. OBJECTIVES: To evaluate the molecular response (MR) in patients with chronic-phase CML (CML-CP) not included in clinical studies and correlate them with the responses obtained in clinical trials. METHODS: Between January 2007 and January 2017, 227 patients newly diagnosed with CML-CP treated with IM as first-line treatment were included. This study is an observational, retrospective, and single-center study. RESULTS: At a median follow-up time of 7.3 years, 60.3% of the 227 patients who started IM were still on IM. Early molecular response (EMR) at 3 and 6 months was achieved by 74.2% and 65%, respectively. The median time to a MMR was nine months. The MR4.0 and MR4.5 were 67.2% and 51.1%, respectively. The overall survival (OS), progression-free survival (PFS), and event-free survival (EFS) of the patients who exclusively used IM were 91%, 91%, and 85.1%, respectively. CONCLUSION: The results presented are similar to those described in prospective and randomized trials, demonstrating that the outcomes are reproducible in the real world. EMR at 3 and 6 months reflects better long-term responses, including higher rates of deeper molecular responses. Considering treatment costs, the absence of literature evidence of an impact on overall survival demonstrated by first-line second-generation tyrosine kinase inhibitors (TKIs), and the global OS of 85.8%, imatinib mesylate (IM) is still an excellent therapeutic option.

Combining gene mutation with gene expression analysis improves outcome prediction in acute promyelocytic leukemia.

By combining the analysis of mutations with aberrant expression of genes previously related to poorer prognosis in both acute promyelocytic leukemia (APL) and acute myeloid leukemia, we arrived at an integrative score in APL (ISAPL) and demonstrated its relationship with clinical outcomes of patients treated with all-trans retinoic acid (ATRA) in combination with anthracycline-based chemotherapy. Based on fms-like tyrosine kinase-3-internal tandem duplication mutational status; the ΔNp73/TAp73 expression ratio; and ID1, BAALC, ERG, and KMT2E gene expression levels, we modeled ISAPL in 159 patients (median ISAPL score, 3; range, 0-10). ISAPL modeling identified 2 distinct groups of patients, with significant differences in early mortality (P < .001), remission (P = .004), overall survival (P < .001), cumulative incidence of relapse (P = .028), disease-free survival (P = .03), and event-free survival (P < .001). These data were internally validated by using a bootstrap resampling procedure. At least for patients treated with ATRA and anthracycline-based chemotherapy, ISAPL modeling may identify those who need to be treated differently to maximize their chances for a cure.

Risk factors and incidence of thrombosis in a Brazilian cohort of patients with Philadelphia-negative myeloproliferative neoplasms.

Few data are available regarding epidemiology and outcomes of Philadelphia-negative chronic myeloproliferative neoplasms (MPN) in Latin America. Therefore, current models for MPN treatment are based in large cohorts of patients from Europe and North America. In this paper, we conducted a retrospective study to evaluate thrombotic and bleeding events in a cohort of patients with MPN from a reference center in Brazil. A total of 334 patients were included, being essential thrombocythemia the most common diagnosis. Here, we found that 41% of the MPN patients had a thrombotic event prior to the diagnosis. Thrombosis was more frequent in patients under 60 years-old. In a multivariable model, only JAK2 V617F mutation (OR 2.57 95% CI 1.58-4.18, p < 0.001) and presence of two cardiovascular risk factors (OR 1.90 95% CI 1.21-2.98, p < 0.005) were significant for thrombosis. The risk of thrombosis was similar among all subtypes of MPN. Cumulative incidence of thromboembolic event at 5 years from diagnosis was 5.8% (95% CI 3.5-8.9), which is similar to previous studies. The high incidence of thromboembolic events in younger patients suggests that socioeconomic disparities might have a role in the outcomes of MPN.

BCR-ABL Mutations in Chronic Myeloid Leukemia Treated With Tyrosine Kinase Inhibitors and Impact on Survival.

This is the largest Latin American study of BCR-ABL mutations in chronic myeloid leukemia (CML) patients, resistant to imatinib (IM). In 195/467 (41%) patients, mutations were detected. The most frequent mutation was T315I (n = 31, 16%). Progression-free (PFS) and overall survival (OS) at 5 years were lower in patients with BCR-ABL mutations (43% vs. 65%, p = 0.07 and 47% vs. 72%, p = 0.03, respectively) and in those with the T315I mutation (p = 0.003 and p = 0.03). OS and PFS were superior in subgroup who switched to second generation inhibitors (SGIs) after IM failure (OS: 50% vs. 39% p = 0.01; PFS: 48% vs. 30% p = 0.02). BCR-ABL mutations conferred a significant poor prognosis in CML patients.

BCR-ABL mutations in chronic myeloid leukemia treated with tyrosine kinase inhibitors and impact on survival.

This is the largest Latin American study of BCR-ABL mutations in chronic myeloid leukemia (CML) patients, resistant to imatinib (IM). In 195/467 (41%) patients, mutations were detected. The most frequent mutation was T315I (n = 31, 16%). Progression-free (PFS) and overall survival (OS) at 5 years were lower in patients with BCR-ABL mutations (43% vs. 65%, p = 0.07 and 47% vs. 72%, p = 0.03, respectively) and in those with the T315I mutation (p = 0.003 and p = 0.03). OS and PFS were superior in subgroup who switched to second generation inhibitors (SGIs) after IM failure (OS: 50% vs. 39% p = 0.01; PFS: 48% vs. 30% p = 0.02). BCR-ABL mutations conferred a significant poor prognosis in CML patients.

Potency and efficacy of pharmacological PIP4K2 inhibitors in acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL), a complex malignancy, displays varying expression profiles of PIP4K2-related genes in adult patients. While PIP4K2A expression is elevated in ALL bone marrow cells compared to healthy bone marrow cells, PIP4K2B is downregulated, and PIP4K2C remains relatively unchanged. Despite the correlation between increased PIP4K2A expression and increased percentage of peripheral blood blasts, clinical outcomes do not strongly correlate with the expression of these genes. Here we investigated the therapeutic potential of three PIP4K2 inhibitors (THZ-P1-2, a131, and CC260) in ALL cell models. THZ-P1-2 emerges as the most effective inhibitor, inducing cell death and mitochondrial damage while reducing cell viability and metabolism significantly. Comparative analyses highlight the superior efficacy of THZ-P1-2 over a131 and CC260. Notably, THZ-P1-2 uniquely disrupts autophagic flux and inhibits the PI3K/AKT/mTOR pathway, indicating a distinct molecular mechanism. In summary, our findings elucidate the differential expression of PIP4K2-related genes in ALL and underscore the potential role of PIP4K2A in disease pathogenesis. The therapeutic promise of THZ-P1-2 in ALL treatment, along with its distinct effects on cell death mechanisms and signaling pathways, enriches our understanding of PIP4K2's involvement in ALL development and offers targeted therapy prospects.

Establishment and validation of analytical reference panels for the standardization of quantitative BCR-ABL1 measurements on the international scale.

BACKGROUND: Current guidelines for managing Philadelphia-positive chronic myeloid leukemia include monitoring the expression of the BCR-ABL1 (breakpoint cluster region/c-abl oncogene 1, non-receptor tyrosine kinase) fusion gene by quantitative reverse-transcription PCR (RT-qPCR). Our goal was to establish and validate reference panels to mitigate the interlaboratory imprecision of quantitative BCR-ABL1 measurements and to facilitate global standardization on the international scale (IS). METHODS: Four-level secondary reference panels were manufactured under controlled and validated processes with synthetic Armored RNA Quant molecules (Asuragen) calibrated to reference standards from the WHO and the NIST. Performance was evaluated in IS reference laboratories and with non-IS-standardized RT-qPCR methods. RESULTS: For most methods, percent ratios for BCR-ABL1 e13a2 and e14a2 relative to ABL1 or BCR were robust at 4 different levels and linear over 3 logarithms, from 10% to 0.01% on the IS. The intraassay and interassay imprecision was <2-fold overall. Performance was stable across 3 consecutive lots, in multiple laboratories, and over a period of 18 months to date. International field trials demonstrated the commutability of the reagents and their accurate alignment to the IS within the intra- and interlaboratory imprecision of IS-standardized methods. CONCLUSIONS: The synthetic calibrator panels are robust, reproducibly manufactured, analytically calibrated to the WHO primary standards, and compatible with most BCR-ABL1 RT-qPCR assay designs. The broad availability of secondary reference reagents will further facilitate interlaboratory comparative studies and independent quality assessment programs, which are of paramount importance for worldwide standardization of BCR-ABL1 monitoring results and the optimization of current and new therapeutic approaches for chronic myeloid leukemia.

Dasatinib overrides imatinib resistance mediated by the F359I residue mutation in two patients with chronic myeloid leukemia.

Despite the beneficial effects of imatinib mesylate, some patients may either not respond or respond suboptimally. Here, we report two chronic myelogenous leukemia patients; one had a suboptimal response according to European LeukemiaNet criteria (a major molecular response was not achieved after 18 months of standard-dose imatinib therapy) and the other had failure with a standard dose of imatinib. At the time of the suboptimal response in patient 1 and the failure in patient 2, we were able to detect the F359I mutation in the BCR-ABL tyrosine kinase domain using DNA sequencing in both patients. Therefore, it was decided to change the therapeutic regimen to dasatinib at a dose of 100 mg once daily in both patients. This change resulted in the achievement of complete cytogenetic remission in patient 1 after 4 months and a major molecular response within 2 and 3 months in both patients. Detection of the F359I mutation in our two cases likely explains the suboptimal response to imatinib in case 1 and the failure in case 2. This implies that in such cases dasatinib should be considered to effectively suppress the mutated clones.

Pretherapeutic expression of the hOCT1 gene predicts a complete molecular response to imatinib mesylate in chronic-phase chronic myeloid leukemia.

In this retrospective study we evaluated the pretherapeutic mRNA expression of the hOCT1 (human organic cation transporter 1) gene in patients with chronic-phase (CP) chronic myeloid leukemia (CML) who varied in terms of their response to imatinib (IM). hOCT1 mRNA was quantified by real-time PCR. Patients were classified as expressing either high (n = 44) or low hOCT1 mRNA (n = 44). The complete cytogenetic response rates observed at 6, 12 and 18 months were 47.7, 84.1 and 91%, respectively, in patients with high hOCT1 mRNA and 47.5, 81.8 and 86.3%, respectively, in patients with low hOCT1 transcripts. The major molecular response rates were not significantly different between patients with high and low hOCT1 mRNA after 6 months of therapy (22.7 vs. 9.1%; p = 0.07), but they were significantly different after 12 months (54.5 vs. 31.8%; p = 0.026) and 18 months (77.2 vs. 56.8%; p = 0.034). Complete molecular responses were observed in 5 patients with low and 17 patients with high hOCT1 mRNA (p = 0.003). The 5-year event-free and overall survival analyses revealed no significant differences between the groups. These data imply that knowledge of the pretherapeutic level of hOCT1 could be a useful marker to predict IM therapy outcome in treatment-naïve CP CML patients.

Evaluation of long-term outcomes, cytogenetic and molecular responses with imatinib mesylate in early and late chronic-phase chronic myeloid leukemia: a report from a single institute.

Here we compare the management and survival outcomes of chronic myeloid leukemia (CML) patients who had early or late imatinib mesylate (IM) therapy. The cytogenetic and molecular responses of 189 CML patients were analyzed. Of this group, 121 patients were classified as the early chronic phase (ECP) group and started IM within 12 months of diagnosis. The other 68 patients were classified as the late chronic phase (LCP) group who had been treated with interferon (IFN)-alpha-2 and crossed over to IM more than 12 months after diagnosis. The overall rates of complete cytogenetic response (CCyR) and major molecular response (MMR) at last follow-up were 83.6 and 78.1% in the ECP and LCP groups, respectively. The CCyR rates were 89.3 (for ECP patients) versus 73.5% (for LCP patients; p < 0.0001). At last follow-up, 82.4% ECP and 64.2% LCP patients had achieved an MMR (p < 0.0001). No significant differences were noted between the two groups with regard to survival outcomes. Our experience reveals that IM is an effective rescue therapy in most CML LCP patients who are intolerant or in whom IFN-alpha therapy fails. Such therapeutic options should be considered in LCP patients, particularly in countries where IM may not be available.

Simultaneous occurrence of biphenotypic T cell/myeloid lesions involving t(12;13)(p13;q14) in a pediatric patient.

This paper chronicles a 2-year-old girl who presented with acute leukemia/lymphoma syndrome of the T cell immunophenotype. At this time, the cytogenetic analysis of her bone marrow cells showed a reciprocal translocation between the short arm of chromosome 12 and the long arm of chromosome 13, t(12;13)(p13;q14). The immunophenotyping of bone marrow blast cells by flow cytometry revealed a population of cells positive for CD56, CD117, CD45, partial CD33, partial HLA-DR, CD13, CD7, CD2 and CD5. Therefore, a diagnosis of acute leukemia with a mixed T cell/myeloid phenotype was made. The patient had a poor response to classic T cell acute lymphocytic leukemia/lymphoma therapy; thus, her treatment was changed to a myeloid leukemia protocol, which produced a good response. She underwent a successful cord blood transplantation from an unrelated HLA partially matched donor. The coexistence of these two phenotypes prompts questions about the existence of clonal instability, which might influence the choice of therapy. The rarity of the t(12;13)(p13;q14) and the coexistence of T cell/myeloid markers suggest a nonrandom association. To the best of our knowledge, this is the first reported case in which a cell clone bearing a t(12;13)(p13;q14) translocation in a mixed T cell/myeloid lesion was detected.

TET-2 mutations predict poor outcomes and are associated with unfavorable clinical-biological features in PTCL, not otherwise specified and angioimmunoblastic T-cell lymphoma in Brazilian patients.

INTRODUCTION: Nodal peripheral T-cell lymphomas [nPTCL] constitute a heterogeneous group of rare malignancies with aggressive biological behavior and poor prognosis. Epigenetic phenomena involving genes that control DNA-methylation and histone deacetylation play a central role in their pathogenesis. However, the mutational landscape involving epigenetic regulators has never been reported in Latin American patients and their prognostic impact remains controversial. PATIENTS AND METHODS: From 2000 to 2019, 59-Brazilian patients with nPTCL were eligible for screening mutations in the IDH-1, IDH-2, RHOA, TET-2 and DNMT3A genes by Sanger sequencing at Formalin-Fixed Paraffin-Embedded samples [FFPE] of diagnosis. We reported the frequency, distribution and potential prognosis of these mutations. RESULTS: With a median follow-up of 3.70 years, estimate 2-year OS and PFS were 57.1% and 49.2%, respectively. Mutations in the IDH-1 gene were not found, mutations in the IDH-2 occurred in 3.4% (2/59), RHOA in 23.7% (14/59), TET-2 in 50.8% (30/59) and DNMT3A in 62.7% (37/59). RHOA gene mutations were more frequent in PTCL, NOS and AITL (p= 0.06). Almost half of the patients had more than one mutation in concomitance, particularly RHOA-mut and TET-2-mut. Mutations in RHOA (p= 0.030) and TET-2 (p= 0.046) were associated with high-tumor burden. In the non-ALCL subgroup (PTCL, NOS and AITL) TET-2 mutations were associated with decreased 2-year PFS [HR: 2.22, p= 0.048]. Likewise with lower overall response rate [ORR] (p= 0.048) and unfavorable clinical features, as bulky disease (p= 0.012), ECOG ⩾ 2 (p= 0.032), B-symptoms (p= 0.012), ⩾ 2 extranodal sites compromised (p= 0.022) and high-risk Prognostic Index for T-cell lymphoma (p= 0.005). CONCLUSION: Mutations in RHOA, TET-2 and DNMT3A were frequent in Brazilian patients with nPTCL. TET-2 mutations were associated with lower ORR for CHOP-like chemotherapy, decreased PFS and unfavorable clinical-biological characteristics in non-ALCL (PTCL, NOS and AITL). Further studies using a larger cohort may validate our findings.

Brazilian chronic myeloid leukemia working group recommendations for discontinuation of tyrosine kinase inhibitors in chronic myeloid leukemia in clinical practice.

INTRODUCTION: Treatment-free remission (TFR) is a new goal of chronic myeloid leukemia (CML) therapy. TFR is feasible when the patient has achieved a deep and stable molecular response and met the criteria required to ensure its success. Treatment discontinuation should not be proposed to the CML patient if minimum conditions are not met. In Brazil, for example, molecular tests (BCR::ABL1) are not broadly available, making it difficult to monitor the patients adequately. OBJECTIVE: In this sense, providing TFR recommendations for Brazilian physicians are therefore necessary. These recommendations include the main criteria checklist to start the TKIs treatment discontinuing process in patients diagnosed with CML and the population-eligible characteristics for treatment discontinuation. METHOD: Age, risk score at diagnosis, TKI treatment duration, BCR::ABL1 transcripts type, depth of the molecular response for treatment discontinuation, treatment adherence, patient monitoring and withdrawal syndrome are essential factors to consider in TFR. After TKI discontinuation, BCR::ABL1 transcripts monitoring should be more frequent. When a major molecular response loss is observed during the monitoring of a patient in TFR, the TKI treatment should be resumed. CONCLUSION: These recommendations should serve as a basis for medical professionals interested in proposing TKI discontinuation for CML patients in clinical practice. It is important to highlight that, despite the benefits of TFR for the patients and the health system, it should only be feasible following the minimum standards proposed in this recommendation.

Adult acute lymphoblastic leukemia in a resource-constrained setting: outcomes after expansion of genetic evaluation.

Acute lymphoblastic leukemia (ALL) is a challenging disease with a growing genetic landscape, even though there is substantial gap between developed and non-developed countries when it comes to availability of such new technologies. This manuscript reports a 5-year retrospective cohort of newly diagnosed ALL patients and their genetic findings and outcomes. An expanded genetic evaluation by using FISH and RT-PCR was implemented, aiming to identify Ph-like alterations. Patients were treated according to our local protocol, which allocated patients according to age and Philadelphia-chromosome status. A total of 104 patients was included, with median age of 37.5 years. Philadelphia chromosome was detected in 33 cases of B-lineage. Among 45 Ph-negative B-lineage, after excluding KMT2A or TCF3-PBX1 cases, we identified 9 cases with Ph-like fusion. Ph-positive and Ph-like patients had higher initial WBC (p = 0.06). Out of 104 cases, two cases did not start chemotherapy and an early death rate of 10.8% was found. Allogeneic transplantation was performed in 18 cases, being ten performed in first CR. Three-year overall survival (OS) and 3-year event-free survival were 42.8% and 30.8%, respectively. For patients treated with a pediatric regimen, 3-year OS was 52.5%. Extramedullary disease (HR 0.42) and platelet counts (HR 0.9) were independently associated with OS. We still face excessive non-relapse mortality that compromises our results. Alternative strategies implementing FISH and RT-PCR are feasible and able to identify Ph-like fusions. Delays in allogeneic transplantation, as well as the unavailability of new agents, impact long-term survival. Measures to decrease early infection are desirable.

Prognostic impact of MYCN, DDX1, TrkA, and TrkC gene transcripts expression in neuroblastoma.

BACKGROUND: The aims of this study were to define the mRNA expression profiles of MYCN, DDX1, TrkA, and TrkC in biopsy tumor samples from 64 Brazilian patients with neuroblastomas of different risk stages and to correlate altered expression with prognostic values. PROCEDURE: Patients were retrospectively classified into low- (n = 11), intermediate- (n = 18), and high-risk (n = 35) groups using standard criteria. The mRNA levels of the above genes were measured by quantitative real-time polymerase chain reaction. Univariate analyses were performed and survival curves were plotted by the Kaplan-Meier method. RESULTS: Of the 64 patients, 53% were female and 62.5% were older than 18 months. The 5-year overall survival (OS) for the entire cohort was 40.3%, with inferior median OS in patients identified in the intermediate- and high-risk groups. A significant difference in OS with respect to TrkA mRNA expression was found for the high-risk group vs. either the low- or intermediate-risk groups (P < 0.01, log rank test). Within the intermediate-risk group, neuroblastoma patients with positive TrkA mRNA expression had better clinical outcomes than patients with no TrkA transcript expression (P = 0.004). Another difference in OS was only found between the intermediate- and high-risk groups (P < 0.027, log rank test). No significant correlation of mRNA expression and survival outcome could be detected for the MYCN, DDX1. CONCLUSIONS: Positive expression of TrkA mRNA may be a clinically useful addition to the current risk classification system, allowing the identification of NB tumors with favorable prognosis.

Challenges in Chronic Myeloid Leukemia Management in South America.

PURPOSE OF REVIEW: Chronic myeloid leukemia (CML) management in developing countries has improved in the last years, but the availability of therapeutic resources, monitoring, reimbursement, and financial issues may be a challenge and interfere with the best practices and results of CML treatment. This review points out the main challenges in CML management in South America. RECENT FINDINGS: In this review, we describe the access to tyrosine kinase inhibitors and monitoring in different countries of South America. We also address the ongoing discontinuation trials, the progress, and limitations of hematopoietic stem cell transplantation in the last years. There are still many challenges for achieving the best outcomes for CML patients in South America. The continuous efforts to provide continuous education, access to tyrosine kinase inhibitors, and monitoring, providing reference centers for CML management and hematopoietic stem cell transplantation may improve patients' outcomes.