FLT3 inhibitors (FLT3i) are drugs in which there is limited experience and not yet enough information on the mechanisms of absorption, transport, and elimination; but especially on the potential ...drug-drug interactions (DDIs). There are therefore risks in the management of FLT3i DDIs (i.e. sorafenib, ponatinib, crenolanib, midostaurin, quizartinib, and gilteritinib) and ignoring them can compromise therapeutic success in acute myeloid leukemia (AML) treatment, in complex patients and secondary pathologies.
This review summarizes the DDIs of FLT3i with P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), organic anion transporting (OAT), organic cationic transporting (OCT), cytochrome P450 (CYP) subunits, and other minor metabolic/transport pathways. EMBASE, PubMed, the Cochrane Central Register and the Web of Science were searched. The last literature search was performed on the 14 February 2022.
FLT3i will be combined with other therapeutic agents (supportive care, doublet, or triplet therapy) and in different clinical settings, which means a greater chance of controlling and even eradicating the disease effectively, but also an increased risk to patients due to potential DDIs. Healthcare professionals should be aware of the potential interactions that may occur and be vigilant in monitoring those patients who are receiving any potentially interacting drug.
Abstract 3539
Microdeletions of genes involved in B lymphopoiesis and cell-cycle regulation, such as CDKN2A/B, PAX5, IKZF1, ETV6, RB1, BTG1 and EBF1 have been reported as a frequent event in ...pediatric acute lymphoblastic leukemia (ALL). Whether these findings are found in adulthood and the possible differences with childhood ALL, as well as its prognostic implication, are still unknown.
To assess the differences between two cohorts of children and adults diagnosed with ALL on the frequency of deletions in these genes and their relationship with clinical data and prognosis.
We studied 70 children and 83 adults diagnosed with ALL with available DNA sample at diagnosis. In children, median age was 4y. (1 – 14), median leukocytes 10.3×109/L (0.7 – 675) and the cytogenetic risk distribution was 42(39%), 30(27%) and 12(11%) for favourable t(12;21) and hyperdiploidy, intermediate (normal karyotype and miscellaneous) and high risk t(9;22), t(4;11), hypodiploid and complex karyotype, respectively. In adults, median age was 38y. (15 – 85), median leukocytes 16.8×109/L (1 – 371) and 29(35%) patients belonged to the high risk cytogenetic group.
We performed Multiplex Ligation Probe Amplification (MLPA) using SALSA kit P335-A1 (MRC-Holland). PCR products were separated on an ABIPRISM 310 DNA Analyzer and analyzed using GeneMapper v3.2 (Applied Biosystems).
Frequency of deletions in the studied genes was similar in children and adults, except for IKZF1 deletions that were more frequent in adults (P<.001) (Table 1).
Table 1.Frequency of deletions.Deletions (%)GenesAdults, N =83Children, N = 70IKZF125 (30%)2 (3%)CDKN2A/B24 (29%)22 (31%)ETV613 (16%)12 (17%)BTG16 (7%)3 (4%)PAX511 (13%)14 (20%)EBF17 (9%)1 (1%)RB110 (12%)7 (10%)X-PAR5 (6%)3 (4%)
In children, ETV6 deletions occurred more frequently in patients with t(12;21) (67% of patients with deletion vs. 17% without, P <.001); CDKN2A/B deletions were found in patients assigned to the intermediate cytogenetic risk group (59% of patients with deletion vs. 23% without, P =.028); and the three cases with RB1 deletions were found in patients with hypodiploidy (P <.001).
In adults, ETV6 and CDKN2A/B deletions occurred more frequently in women (67% vs. 39%, P =.022 and 77% vs. 42%, P =.021, for patients with and without deletions, respectively); PAX5 and IKZF1 deletions appeared more frequently in patients with >30×109/L leukocytes (60% vs. 27%, P =.032 and 52% vs. 21%, P =.007, for patients with and without deletions, respectively); besides, PAX5 deletions occurred in patients who belonged to the standard cytogenetic risk group (55% vs. 6% for patients with and without deletions, P <.001).
In the pediatric cohort, the leukocytes >30×109/L and the cytogenetic risk group were the variables that reached statistical significance for both overall survival (OS) and relapse free survival (RFS) and also age >10y. for OS, but in the multivariate analyses, just the cytogenetic risk classification remained significant HR: 4 (CI 95%: 1.6 – 10), P =. 004 for OS and HR: 3.5 (CI 95%: 1.7 – 7.2), P =. 001 for RFS.
In the adult cohort, multivariate analysis for OS including all significant variables in the univariate analysis (age >60y, karyotype, CDKN2A/B and ETV6 deletions) showed as independent variables: age >60y. HR: 4.3 (CI 95%: 2.1 – 8.6), P<. 001 and CDKN2A/B deletions HR: 2.6 (CI 95%: 1.4 – 5.3), P=. 004. Similarly, taking into account karyotype, CDKN2A/B and ETV6 deletions for the RFS multivariate analyses, just ETV6 deletions arose as an independent factor HR: 3.8 (CI 95%: 1.5 – 9.4), P=. 004. In fact, having CDKN2A/B and/or ETV6 deletions conferred a worse prognosis to patients in both standard risk cytogenetic group (3y. RFS: 45% vs. 70% for patients with and without deletions, respectively; P =.049) and high risk cytogenetic group (3y. RFS: 14% vs. 66% for patients with and without deletions, respectively; P =.025).
This study shows the high incidence of deletions in genes of cell-cycle and B-lymphopoiesis in adult and pediatric ALL. However, the biological and prognostic implications of these deletions seem to differ between both patient groups: while cytogenetics was the strongest variable for risk assessment in children, gene microdeletions in CDKN2A/B and ETV6 added a prognostic value to karyotype in our adult cohort.
AP-194/10, R06/0020/0031, BES2008–008053, CM10/00321, CM09/00038, and CA08/00141.
No relevant conflicts of interest to declare.
Abstract 1469
The Wilms Tumor 1 (WT1) gene was first described as a tumour suppressor gene, but its accurate role in leukemia development has not been completely elucidated. Some authors support the ...role of WT1 as a prognostic marker in acute myeloid leukemia (AML) based on the assessment of its expression at the mRNA level. However, the prognostic value of the main isoforms of WT1 has been less studied.
The aim of this study was to develop a specific quantitative assay to estimate the ratio of expression of the four major WT1 isoforms (A, 5-/KTS-; B, 5+/KTS-; C, 5-/KTS+; D, 5+/KTS+) and to evaluate their prognostic impact.
WT1 expression was analyzed in bone marrow samples from 108 patients with AML at diagnosis (65 male/46 female, median age: 61 yr, range: 17 – 91). Likewise, peripheral blood samples of 20 healthy donors and 6 samples of cord blood CD34+ cell selection were analyzed as normal controls. We performed a new method to quantify the ratios of the four major isoforms of WT1. Briefly, to amplify all isoforms within a PCR reaction, specific WT1 primers flanking exon 4 to exon 10 were used in cDNA samples, followed by capillary electrophoresis with laser-induced fluorescence analysis on an ABIPRISM 310 DNA Analyzer (Applied Biosystems, Foster City, CA) and lastly analyzed with the Gene Mapper 4.2 software (Applied Biosystems). The amount of each isoform was calculated by the area under the curve. Subsequent comparisons of isoform ratios were made by standardized calculation of percentage. All values are given as the mean of duplicate PCRs. In parallel, RQ-PCR for total WT1 detection was performed as previously described by Barragan et al. (Haematologica 2004; 89: 926–933). GUS gene was used as housekeeping gene.
Eighteen patients (17%) did not express WT1, while 90 patients (83%) overexpressed WT1 above background levels. The median value of each WT1 isoform was: 18% (range: 2 – 73) for A isoform; 16% (range: 7 – 63) for B isoform; 24% (range: 2 – 52) for C isoform; and 33% (range: 3 – 55) for D isoform. None of healthy donors had detectable WT1 levels in peripheral blood. All samples of CD34+ cells expressed the four isoforms of WT1: 21% (range: 2 – 26) for A isoform; 16% (range: 1 – 64) for B isoform; 24% (range: 1 – 47) for C isoform; and 36% (range: 25 – 44) for D isoform. These data reveal that, in our series, the most predominant isoform was +5/+KTS, both in AML and in cord blood CD34+ cell selection samples. There were no significant differences when comparing the proportion of each isoform between the cord blood CD34+ cell selection samples and the cohort of AML patients. There was not significant correlation between the overexpression of total WT1 with the ratio of each isoform, and we were unable to demonstrate that the overexpression of WT1 is due to a particular isoform overexpression. A significant lower event-free survival (EFS) was observed in those patients overexpressing total WT1, taking a cut-off value of 3000 WT1 copies/ GUS copies × 104 (75th percentile, P =.001). However, when the same cut-off as well as the median value for each one of the isoforms was used, we found no significant differences in EFS and in overall survival.
To sum up, none of the isoforms were correlated with overexpression of total WT1 or survival. We were unable to find differences between the expression of each isoform of WT1 in CD34+ cells from normal cord blood and in AML patients. Further studies including larger controls need to be carried out.
No relevant conflicts of interest to declare.
Abstract 1450
The clinical relevance and prognostic implications of some recently identified mutations in acute myeloid leukemia (AML) is not yet well established. Among them, we have selected to be ...analyzed those affecting the following genes: Additional Sex Combs-Like 1 (ASXL1), Isocitrate Dehydrogenase (IDH1 and IDH2), Casitas B-lineage Lymphoma (c-CBL), and Wilms Tumor 1 (WT1). They have been previously reported with a variable incidence: ASXL1 mutations in 10.8% patients with normal karyotype (NK), IDH1 and IDH2 mutations in 8 – 33% of de novo AML, c-CBL mutations in 2% of de novo AML, and WT1 mutations in 5–12% of de novo AML patients.
In order to know the incidence and prognostic impact of these mutations and their possible cooperative role in leukemogenesis, we have screened for ASXL1, IDH1, IDH2, c-CBL, WT1, FLT3, NPM1 and CEBPa, mutations in a cohort of de novo AML patients from a single centre.
We studied 174 de novo AML patients 98M/76F; median age: 62 yr. (range: 16 – 88); favourable (n= 13), intermediate (n= 86) and high (n= 51) cytogenetic risk classification by the MRC group. DNA was isolated from bone marrow samples obtained at diagnosis.
In order to determine cooperating mutations, we developed a new combination of high-resolution melting (HRM) assays on a LightCycler® 480 and lastly direct sequencing, to detect somatic mutations for ASXL1 (exon 12), IDH1 (exon 4), IDH2 (exon 4), WT1 (exons 7, 8 and 9) and c-CBL (exons 8 and 9). All mutations reported in this study were confirmed al least twice. FLT3 (ITD and D835Y), NPM1 (exon 12) and CEBPa were performed as described previously by standard methods. Sequence analysis was checked by its corresponding GeneBank Accession Number.
The number of patients found to carry mutations in our series was: 16 patients with ASXL1 mutations (9.2%), 16 patients with IDH mutations (2.9% had a IDH1R132, 12.6% the SNP rs11554137 and 6.3% IDH2R140), 5 patients with WT1 mutations (2.9%), 37 patients with FLT3 mutations (21.3%), 44 patients with NPM1 mutations (25,3%) and 8 patients with CEBPa mutations (4.6%). No mutations where found in c-CBL.
We could not found a pattern of cooperating mutations in the studied group of genes. WT1, FLT3 and NPM1 were associated with leukocyte count >30 × 109/L at diagnosis (80% vs. 31% for WT1, P =0,022; 68% vs. 22% for FLT3, P= 0.001; and 50% vs. 24% for NPM1, P= 0.002; in mutated vs. wild-type patients, respectively). WT1 was also associated with a platelet count > 50 × 109/L at diagnosis (100% vs. 57% in mutated vs. wild-type patients, respectively; P =0,048). Besides, FLT3 and NPM1 mutations were more frequent in the intermediate cytogenetic risk group (82% and 74%; P =0.004 and P =0.047; respectively). ASXL1 and IDH mutations were not correlated with any of the clinical and biological features studied.
In univariate analysis, only age and cytogenetics had an impact on overall survival (OS, median of 12mo vs. 3mo, for patients < and ≥65 yr., P <0.001 and 24mo, 11mo and 3mo for favourable, intermediate and high risk, P =0.005). Mutational status of ASXL1, IDH1, IDH2, WT1, FLT3, NPM1 and CEBPa did not impact on outcome in the whole series. However, when the analysis was restricted to patients with intermediate cytogenetic risk, patients with FLT3 mutations had a shorter OS (19mo vs. 8mo, wild-type vs. mutated patients; P =0.047) and those with WT1 mutations showed a trend towards an inferior OS (11mo vs. 1mo, wild-type vs. mutated patients; P = 0.066).
In multivariate analysis in patients with intermediate cytogenetic risk, the age HR (95% CI) = 3.3 (1.9 − 5.9) P <0.001, and FLT3 status HR (95% CI) = 2.2 (1.2–3.9) P =0.008 retained an independent adverse significance for OS. In terms of relapse free survival any of the variables showed a significant implication.
To sum up, the incidence found for the studied genes was lower than the previously reported: ASXL1, 9.2%; IDH1R132, 2.9%; IDH2R140, 6.3%; WT1, 2.9%; and c-CBL, 0%. We were unable to find a pattern of cooperating mutations in the studied group of genes or any impact of these mutations on the outcome.
No relevant conflicts of interest to declare.
Next-generation sequencing (NGS) has redefined the genetic landscape of acute myeloid leukemia (AML), providing new molecular markers for diagnostic and prognostic classifications. However, its ...application in the clinical setting is still challenging. We hypothesized that a 19-gene AML-targeted NGS panel could be a valid approach to obtain clinically relevant information. Thus, we assessed the ability of this panel to classify AML patients according to diagnostic and prognostic indexes in a cohort of 162 patients. The assay yielded a median read depth >2000×, with 88% of on-target reads and a mean uniformity >93% without significant global strand bias. The method was sensitive and specific, with a valid performance at the clinical variant allele frequency cutoff of 3% for point mutations and 5% for insertions or deletions (INDELs). Three-hundred thirty-nine variants were found (36% INDELs and 64% single nucleotide variants). Concordance between NGS and other conventional techniques was 100%, but the NGS approach was able to identify more clinically relevant mutations. Finally, all patients could be classified into one of the 2016 World Health Organization diagnostic categories and virtually all into the recently proposed prognostic indexes (2017 European LeukemiaNet and Genomic classification). To sum up, we validate a reliable and reproducible method for AML diagnosis and demonstrate that small, well-designed NGS panels are sufficient to guide clinical decisions according to the current standards.
Prognosis for relapsed or refractory (R/R) acute myeloid leukemia (AML) despite salvage therapy is dismal. This phase I dose-escalation trial assessed the safety and preliminary clinical activity of ...selinexor, an oral exportin-1 (XPO1) inhibitor, in combination with FLAG-Ida in younger R/R AML patients. The aim was to find the recommended phase 2 dose (RP2D) and maximum tolerated dose (MTD). Fourteen patients were included, and selinexor dosage was 60 mg (3 patients), 80 mg (3 patients), and 100 mg (7 patients) weekly. No dose-limiting toxicities were reported. Grade ≥3 non-hematologic adverse events (AEs) occurred in 78.6% of patients. Two patients were non MTD evaluable due to early death, and overall, 3 out of 14 patients (21.4%) had fatal AEs. Five out of 12 (42%) response and MTD evaluable patients achieved a complete remission (CR;
n
=4) or CR with incomplete hematologic recovery (CRi,
n
=1), and 4 patients (33%) subsequently underwent allogeneic transplantation. The median overall survival (OS) and event-free survival (EFS) were 6.0 (range 0.9-19.3) and 1.1 months (range 0.7-19.3), respectively. Using selinexor 100 mg/weekly, CR/CRi rate of 66.7%, OS 13.6 months (range, 1.6-19.3), and EFS 10.6 months (range, 0.9-19.3). At last follow-up, 3 patients were alive. Selinexor 100 mg/weekly with FLAG-Ida combination in R/R AML showed acceptable tolerability and efficacy, establishing the RP2D of this regimen in future clinical trials.
ClinicalTrials.gov
Identifier: NCT03661515
Hyperleukocytosis in acute myeloid leukemia (AML) is associated with inferior outcomes. There is limited high quality evidence to support the benefits of leukapheresis. We retrospectively collected ...data from patients with newly-diagnosed AML who presented with a white cell count (WBC) >50 × 10
/L to 12 centers in the United States and Europe from 2006 to 2017 and received intensive chemotherapy. Logistic regression models estimated odds ratios for 30-day mortality and achievement of composite complete remission (CRc). Cox proportional hazard models estimated hazard ratios for overall survival (OS). Among 779 patients, clinical leukostasis was reported in 27%, and leukapheresis was used in 113 patients (15%). Thirty-day mortality was 16.7% (95% CI: 13.9-19.3%). Median OS was 12.6 months (95% CI: 11.5-14.9) among all patients, and 4.5 months (95% CI: 2.7-7.1) among those ≥65 years. Use of leukapheresis did not significantly impact 30-day mortality, achievement of CRc, or OS in multivariate analysis based on available data or in analysis based on multiple imputation. Among patients with investigator-adjudicated clinical leukostasis, there were statistically significant improvements in 30-day mortality and OS with leukapheresis in unadjusted analysis, but not in multivariate analysis. Given the significant resource use, cost, and potential complications of leukapheresis, randomized studies are needed to evaluate its value.
Genetic variability in anthracycline metabolism could modify the response and safety of acute myeloid leukemia (AML) induction.
Polymorphisms in genes that encodes enzymes of anthracyclines metabolic ...pathway (CBR3: rs1056892, rs8133052, NQO1: rs1800566, NQO2: rs1143684, NOS3: rs1799983, rs2070744) were evaluated in 225 adult de novo AML patients.
The variant CBR3 rs8133052 was associated with lower hepatotoxicity (P = 0.028). Wild-type genotype of NQO2 rs1143684 was related to higher complete remission (P = 0.014), and the variant allele with greater gastrointestinal toxicity (P = 0.024). However, the variant genotype of NQO1 rs1800566 was associated with mucositis (P = 0.018), but heterozygous genotype showed less gastrointestinal toxicity (P = 0.028) and thrombocytopenia (P = 0.009). Protective effects against nephrotoxicity and thrombocytopenia were reported with variant NOS3 rs1799983 (P = 0.006, P = 0.014), whereas carriers of NOS3 rs2070744 showed higher hepatotoxicity and thrombocytopenia (P = 0.017, P = 0.013).
This study supports the influence of genetic variability of idarubicin metabolizing could be critical in predicting anthracycline-induced toxicities.
The most important challenges in acute promyelocytic leukemia (APL) is preventing early death and reducing long-term events, such as second neoplasms (s-NPLs). We performed a retrospective analysis ...of 2670 unselected APL patients, treated with PETHEMA “chemotherapy based” and “chemotherapy free” protocols. Only de novo APL patients who achieved complete remission (CR) and completed the three consolidation cycles were enrolled into the analysis. Out of 2670 APL patients, there were 118 (4.4%) who developed s-NPLs with the median latency period (between first CR and diagnosis of s-NPL) of 48.0 months (range 2.8–231.1): 43.3 (range: 2.8–113.9) for s-MDS/AML and 61.7 (range: 7.1–231.1) for solid tumour. The 5-year CI of all s-NPLs was of 4.43% and 10 years of 7.92%. Among s-NPLs, there were 58 cases of s-MDS/AML, 3 cases of other hematological neoplasms, 57 solid tumours and 1 non-identified neoplasm. The most frequent solid tumour was colorectal, lung and breast cancer. Overall, the 2-year OS from diagnosis of s-NPLs was 40.6%, with a median OS of 11.1 months. Multivariate analysis identified age of 35 years (hazard ratio = 0.2584;
p
< 0.0001) as an independent prognostic factor for s-NPLs. There were no significant differences in CI of s-NPLs at 5 years between chemotherapy-based vs chemotherapy-free regimens (hazard ratio = 1.09;
p
= 0.932). Larger series with longer follow-up are required to confirm the potential impact of ATO+ATRA regimens to reduce the incidence of s-NPLs after front-line therapy for APL.
Anthracycline uptake could be affected by influx and efflux transporters in acute myeloid leukemia (AML). Combinations of single-nucleotide polymorphisms (SNPs) of wild-type genotype of influx ...transporters (SLC22A16, SLCO1B1) and homozygous variant genotypes of ABC polymorphisms (ABCB1, ABCC1, ABCC2, ABCG2) were evaluated in 225 adult de novo AML patients. No differences in complete remission were reported, but higher induction death was observed with combinations of SLCO1B1 rs4149056 and ABCB1 (triple variant haplotype, rs1128503), previously associated with ABCB1 and SLCO1B1 SNPs. Several combinations of SLCO1B1 and SLC22A16 with ABCB1 SNPs were associated with higher toxicities, including nephrotoxicity and hepatotoxicity, neutropenia, previously related to ABCB1, and a novel correlation with mucositis. Combination of SLC22A16 rs714368 and ABCG2 rs2231142 was related to cardiac toxicity, reproducing previous correlations with ABCG2. This study shows the impact of transporter polymorphisms in AML chemotherapy safety. Further prospective studies with larger populations are needed to validate these associations.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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