PH negative acute lymphoblastic leukemia in adolescents and young adults treated according a MRD adapted BFM ALL IC 2009 protocol: Argentine real-world data on 171 patients.

Intensified pediatric chemotherapy regimens to treat adolescents and young adults (AYA) patients with Philadelphia negative acute lymphoblastic leukemia (ALL) have been associated with better outcomes. The local BFM 2009-based scheme complements the risk stratification assessing the measurable residual disease (MRD) along the induction phase with increasing levels of sensitivity. The present retrospective multicenter analysis included 171 AYA (15-40 years) patients treated accordingly between 2013 and 2019. Ninety-one percent obtained morphological complete remission, 67% a negative (<0.1%) MRD at day 33 (TP1), and 78% a negative (<0.01%) MRD at day 78 (TP2). The overall survival (OS) and the event-free survival (EFS) at 2 years were 62%±4.1 and 55%±4.1, respectively. The OS and EFS were significant better for prednisone responders, who achieved <10% BM blast at day 15, a negative MRD at TP1 or at TP2, and for low-risk patients. Age ≤30 years and WBC <30×109/L, particularly among B-phenotype, were also associated with longer OS. In the multivariable analyses, TP1 MRD positive (OS HR 2.8, 95% CI 1.4-5.7, p=0.004; EFS HR 3.0, 95% CI 1.6-5.7, p=0.001) and at TP2 (OS HR 2.6, 95% CI 1.3-5.3, p=0.012; EFS HR 2.6, 95% CI 1.3-5.1, p=0.006) were independently associated with earlier events. Age >30 years was also associated with a shorter survival (HR 3.1, 95% CI 1.3-7.5, p=0.014). Therefore, those 68 patients ≤30 years with TP1/TP2 negative MRD depicted a longer OS (2 years 85%±4.8). Based on our real-world data, the pediatric-based scheme is feasible in Argentina associated with better outcomes for younger AYA patients who achieved negative MRD at day 33 and 78.

Expression dynamics of the immune mediators ARG1, TBET, CIITA, IL10 and TGFB1 in chronic myeloid leukaemia patients during the first year of imatinib therapy.

The use of tyrosine kinase inhibitors seems to restore the broadly compromised immune system described in chronic myeloid leukaemia (CML) patients at diagnosis leading to a re-activation of the effector-mediated immune surveillance. Here, we describe the expression dynamics of immune factors during the first year on imatinib therapy. Gene expression was evaluated in 132 peripheral blood samples from 79 CML patients, including 34 who were serially followed. An aliquot of the stored sample used to monitor BCR-ABL1 levels was retro-transcribed to cDNA and gene expression was quantified by real-time PCR. An elevated expression of ARG1 was observed at diagnosis, while TBET, CIITA, IL10 and TGFB1 were significantly decreased. Once on therapy, each gene displayed a particular behaviour. ARG1 normalized to control levels at 3 months only in optimal molecular responders and was identified as the major contributor to the difference among patients. TBET reached normal levels after 12 months in optimal responders and non-responders, regardless the Th1-response previously associated, and CIITA continued downregulated. IL10 and TGFB1 achieved normal levels early at 3 months in both groups, afterwards IL10 was sustained while TGFB1 was slightly increased after 1 year in responders. Our findings are in agreement with an immune re-activation after imatinib initiation; however, some immune mediators may require a longer exposition. The follow-up of novel and reliable biomarkers, such as ARG1, one of the principal mechanisms of myeloid-derived-suppressor cells to inhibit immune system, may be useful to deepen the characterization of early responder patients.

Partial and total monosomal karyotypes in myelodysplastic syndromes: comparative prognostic relevance among 421 patients.

Myelodysplastic syndromes (MDS) include a group of heterogeneous hematological disorders with a variable risk of leukemic evolution and short survival. Around 40-50% of patients show abnormal karyotypes that are mostly characterized by monosomies or deletions. Cytogenetic findings are an independent prognostic factor and the International prognostic scoring system (IPSS) differentiates three cytogenetic categories, despite the Intermediate one being heterogeneous. The aim of this study, including 421 Argentinean patients with primary MDS, is to characterize the cytogenetic profile, to test its prognostic value and to compare partial and monosomal karyotypes against other cytogenetic findings. An abnormal karyotype (median survival: 26 months) was observed in 176 patients. The presence of complex karyotypes, number of alterations, and the IPSS cytogenetic groups showed significant differences for predicting outcome. Behavior of patients with isolated deletions (median survival: 49 months) did not differ from those with normal karyotype (56 months, P = 0.654) or Good prognostic findings (43 months, P = 0.371). However, a worse prognosis was observed when another alteration was added (31 months, P = 0.043). Karyotypes with autosomal monosomies (median survival: 16 months) had a prognostic impact similar to other Poor cytogenetic findings (17 months, P = 0.626). In our population classified according to French-American-British (FAB) or World Health Organization (WHO), this new categorization of cytogenetic abnormalities, recognizing three different risk groups, showed an independent prognostic impact and a better discriminating power than the IPSS categories. It can be concluded that all isolate deletions (excluding 7q-) are good prognostic findings and all monosomies (excluding Y chromosome loss) are bad indicators.

Molecular monitoring of imatinib in chronic myeloid leukemia patients in complete cytogenetic remission: does achievement of a stable major molecular response at any time point identify a privileged group of patients? A multicenter experience in Argentina and Uruguay.

BACKGROUND: Monitoring minimal residual disease (MRD) by real-time quantitative polymerase chain reaction (RT-PCR) in chronic myeloid leukemia (CML) patients is mandatory in the era of tyrosine kinase inhibitors. Achieving a major molecular response (MMR) at 12 and 18 months predicts a better progression and event-free survival. PATIENTS AND METHODS: The objective of this prospective, multicentric study was to evaluate MRD by standardized RT-PCR in 178 patients with chronic-phase CML who were treated with imatinib at different institutions in Argentina and Uruguay and to determine if achievement of a stable MMR (BCR-ABL transcript levels < 0.1%) identifies a low-risk cytogenetic relapse group. The median age of the patients was 50 years, and 55% of them had received imatinib as first-line therapy. BCR-ABL transcript levels were measured after achievement of complete cytogenetic remission (CCyR) and at 6-month intervals. RESULTS: MMR was detected in 44% patients at the start of the study. This value increased to 79% at month 36 of evaluation. Complete molecular response (CMR) also increased from 24% to 52% of patients. Not achieving a stable MMR determined a higher risk of cytogenetic relapse (9% of MMR patients not achieving an MMR vs. 1% of patients who achieved MMR). Patients with sustained MMR had a significantly better cytogenetic relapse-free survival at 48 months (97% vs. 87%; P = .008) but showed no differences in overall survival. Patients who did not remain in CCyR changed treatment. CONCLUSIONS: A stable MMR is a strong predictor for a durable CCyR. Standardized molecular monitoring could replace cytogenetic analysis once CCyR is obtained. These results emphasize the validity and feasibility of molecular monitoring in all standardized medical centers of the world.

Amplification of the BCR/ABL fusion gene clustered on a masked Philadelphia chromosome in a patient with myeloblastic crisis of chronic myelocytic leukemia.

Although the chronic phase of chronic myelocytic leukemia (CML) is characterized by the Philadelphia (Ph) chromosome creating a hybrid BCR/ABL gene, additional genetic changes involved in blast crisis are poorly understood. We report a 4-8-fold amplification by tandem duplication of the BCR/ABL fusion gene clustered on a masked Ph chromosome in a 61-year-old male patient with CML in myeloblastic crisis. Our finding suggests that the BCR/ABL amplification may play a role as a novel mechanism in the progression to an aggressive blast transformation in some cases of Ph-positive CML.