Both SEPT2 and MLL are down-regulated in MLL-SEPT2 therapy-related myeloid neoplasia

<p>Abstract</p> <p>Background</p> <p>A relevant role of septins in leukemogenesis has been uncovered by their involvement as fusion partners in <it>MLL</it>-related leukemia. Recently, we have established the <it>MLL-SEPT2 </it>gene fusion as the molecular abnormality subjacent to the translocation t(2;11)(q37;q23) in therapy-related acute myeloid leukemia. In this work we quantified <it>MLL </it>and <it>SEPT2 </it>gene expression in 58 acute myeloid leukemia patients selected to represent the major AML genetic subgroups, as well as in all three cases of <it>MLL-SEPT2</it>-associated myeloid neoplasms so far described in the literature.</p> <p>Methods</p> <p>Cytogenetics, fluorescence in situ hybridization (FISH) and molecular studies (RT-PCR, qRT-PCR and qMSP) were used to characterize 58 acute myeloid leukemia patients (AML) at diagnosis selected to represent the major AML genetic subgroups: <it>CBFB-MYH11 </it>(n = 13), <it>PML-RARA </it>(n = 12); <it>RUNX1-RUNX1T1 </it>(n = 12), normal karyotype (n = 11), and <it>MLL </it>gene fusions other than <it>MLL-SEPT2 </it>(n = 10). We also studied all three <it>MLL-SEPT2 </it>myeloid neoplasia cases reported in the literature, namely two AML patients and a t-MDS patient.</p> <p>Results</p> <p>When compared with normal controls, we found a 12.8-fold reduction of wild-type <it>SEPT2 </it>and <it>MLL-SEPT2 </it>combined expression in cases with the <it>MLL-SEPT2 </it>gene fusion (p = 0.007), which is accompanied by a 12.4-fold down-regulation of wild-type <it>MLL </it>and <it>MLL-SEPT2 </it>combined expression (p = 0.028). The down-regulation of <it>SEPT2 </it>in <it>MLL-SEPT2 </it>myeloid neoplasias was statistically significant when compared with all other leukemia genetic subgroups (including those with other <it>MLL </it>gene fusions). In addition, <it>MLL </it>expression was also down-regulated in the group of <it>MLL </it>fusions other than <it>MLL-SEPT2</it>, when compared with the normal control group (p = 0.023)</p> <p>Conclusion</p> <p>We found a significant down-regulation of both <it>SEPT2 </it>and <it>MLL </it>in <it>MLL-SEPT2 </it>myeloid neoplasias. In addition, we also found that <it>MLL </it>is under-expressed in AML patients with <it>MLL </it>fusions other than <it>MLL-SEPT2</it>.</p

Translocation (2;11)(q37;q23) in therapy-related myelodysplastic syndrome after treatment for acute promyelocytic leukemia

Treatment of acute promyelocytic leukemia (APL) with a combination of anthracycline-based chemotherapy and all-trans retinoic acid (ATRA) leads to very high rates of complete remission and survival. There are only a limited number of publications on the development of therapy-related myelodysplastic syndrome (MDS) or acute myeloid leukemia during follow-up of APL. Although drugs targeting at DNA-topoisomerase II characteristically induce translocations involving 11q23, this was seldom seen in patients treated for APL. We report on a patient initially diagnosed with APL. Response to therapy was monitored by fluorescence in situ hybridization (FISH) and reverse-transcriptase polymerase chain reaction for the PML-RARalpha rearrangement. Consecutive samples showed a swift and complete reduction of PML-RARalpha rearranged cells. Twenty months after diagnosis, however, conventional cytogenetics revealed a complex karyotype with a translocation involving 11q23 and loss of chromosomes 7q and Xq. FISH analysis with the MLL probe identified 2q37 (harboring the SEPT2 gene) as the translocation partner of chromosome 11. We consider the rather unique t(2;11)(q37;q23) as the primary event causing therapy-related MDS in our patient. This case stresses the importance of conventional karyotyping to be performed on a regular basis in all treated APL patients for the early detection of chromosomal aberrations that indicate the development of therapy-related MDS or acute myeloid leukemi

Expression pattern of the septin gene family in acute myeloid leukemias with and without MLL-SEPT fusion genes

Septins are proteins associated with crucial steps in cell division and cellular integrity. In humans, 14 septin genes have been identified, of which five (SEPT2, SEPT5, SEPT6, SEPT9, and SEPT11) are known to participate in reciprocal translocations with the MLL gene in myeloid neoplasias. We have recently shown a significant down-regulation of both SEPT2 and MLL in myeloid neoplasias with the MLL-SEPT2 fusion gene. In this study, we examined the expression pattern of the other 13 known septin genes in altogether 67 cases of myeloid neoplasia, including three patients with the MLL-SEPT2 fusion gene, four with MLL-SEPT6 fusion, and three patients with the MLL-SEPT9 fusion gene. When compared with normal controls, a statistically significant down-regulation was observed for the expression of both MLL (6.4-fold; p=0.008) and SEPT6 (1.7-fold; p=0.002) in MLL-SEPT6 leukemia. Significant down-regulation of MLL was also found in MLL-MLLT3 leukemias. In addition, there was a trend for SEPT9 down-regulation in MLL-SEPT9 leukemias (4.6-fold; p=0.077). Using hierarchical clustering analysis to compare acute myeloid leukemia genetic subgroups based on their similarity of septin expression changes, we found that MLL-SEPT2 and MLL-SEPT6 neoplasias cluster together apart from the remaining subgroups and that PML-RARA leukemia presents under-expression of most septin family gene

Obinutuzumab pretreatment abrogates tumor lysis risk while maintaining undetectable MRD for venetoclax + obinutuzumab in CLL

Early data on venetoclax-containing regimens for the treatment of chronic lymphocytic leukemia (CLL) show promising results with deep remissions, but are hampered by potential risk for tumor lysis syndrome (TLS). Whether optimal duration of venetoclax treatment can be guided by minimal residual disease (MRD) is currently unknown. To study whether TLS risk can be mitigated in an unfit population by introducing preinduction, and whether MRD-guided duration of venetoclax treatment is a feasible and efficacious approach, we performed the Dutch-Belgian Cooperative Trial Group for Hemato-oncology (HOVON) 139/GIVE trial. The study treatment consists of 4 treatment phases: preinduction (2 cycles obinutuzumab), induction I (6 cycles obinutuzumab and venetoclax), induction II (6 cycles venetoclax), and a randomization phase (group A: maintenance with 12 additional cycles of venetoclax irrespective of MRD; group B: MRD guided venetoclax maintenance with a maximum of 12 cycles). Here we report on a planned interim safety analysis as well as preliminary efficacy and MRD data of the first 30 patients enrolled. Downgrading of TLS risk after preinduction occurred in 25 patients: 3 from high to medium, 3 from high to low, and 19 from medium to low risk. No patient remained high risk. From these 30 patients, peripheral blood MRD data were obtained for 28 patients at the end of induction II (6 months after the last obinutuzumab dose), of whom 26 had undetectable MRD levels, and for 18 patients who reached the 3-month after-randomization point, of whom 16 had undetectable MRD levels. Obinutuzumab preinduction is tolerated well in these unfit patients and results in abrogating high TLS risk in all patients. Preliminary data indicate that efficacy is maintained with a high proportion of patients with undetectable MRD levels after combination treatment

Minimal residual disease-guided stop and start of venetoclax plus ibrutinib for patients with relapsed or refractory chronic lymphocytic leukaemia (HOVON141/VISION): primary analysis of an open-label, randomised, phase 2 trial

Background: Targeted time-limited treatment options are needed for patients with relapsed or refractory chronic lymphocytic leukaemia. The aim of this study was to investigate the efficacy of minimal residual disease (MRD)-guided, time-limited ibrutinib plus venetoclax treatment in this patient group. Methods: HOVON141/VISION was an open-label, randomised, phase 2 trial conducted in 47 hospitals in Belgium, Denmark, Finland, the Netherlands, Norway, and Sweden. Eligible participants were aged 18 years or older with previously treated chronic lymphocytic leukaemia with or without TP53 aberrations; had not been exposed to Bruton tyrosine-kinase inhibitors or BCL2 inhibitors; had a creatinine clearance rate of 30 mL/min or more; and required treatment according to International Workshop on Chronic Lymphocytic Leukemia 2018 criteria. Participants with undetectable MRD (10 −2) during observation reinitiated treatment with ibrutinib plus venetoclax. The primary endpoint was progression-free survival at 12 months after random assignment in the treatment cessation group. Progression-free survival was analysed in the intention-to-treat population. All patients who received at least one dose of study drug were included in the safety assessment. The study is registered at ClinicalTrials.gov, NCT03226301, and is active but not recruiting. Findings: Between July 12, 2017, and Jan 21, 2019, 230 patients were enrolled, 225 of whom were eligible. 188 (84%) of 225 completed treatment with ibrutinib plus venetoclax and were tested for MRD at cycle 15. After cycle 15, 78 (35%) patients had undetectable MRD and 72 (32%) were randomly assigned to a treatment group (24 to ibrutinib maintenance and 48 to treatment cessation). The remaining 153 patients were not randomly assigned and continued with ibrutinib monotherapy. Median follow-up of 208 patients still alive and not lost to follow-up at data cutoff on June 22, 2021, was 34·4 months (IQR 30·6–37·9). Progression-free survival after 12 months in the treatment cessation group was 98% (95% CI 89–100). Infections (in 130 [58%] of 225 patients), neutropenia (in 91 [40%] patients), and gastrointestinal adverse events (in 53 [24%] patients) were the most frequently reported; no new safety signals were detected. Serious adverse events were reported in 46 (40%) of 116 patients who were not randomly assigned and who continued ibrutinib maintenance after cycle 15, eight (33%) of 24 patients in the ibrutinib maintenance group, and four (8%) of 48 patients in the treatment cessation group. One patient who was not randomly assigned had a fatal adverse event (bleeding) deemed possibly related to ibrutinib. Interpretation: These data point to a favourable benefit–risk profile of MRD-guided, time-limited treatment with ibrutinib plus venetoclax for patients with relapsed or refractory chronic lymphocytic leukaemia, suggesting that MRD-guided cessation and reinitiation is feasible in this patient population. Funding: AbbVie and Janssen

Minimal residual disease-guided stop and start of venetoclax plus ibrutinib for patients with relapsed or refractory chronic lymphocytic leukaemia (HOVON141/VISION):primary analysis of an open-label, randomised, phase 2 trial

Background: Targeted time-limited treatment options are needed for patients with relapsed or refractory chronic lymphocytic leukaemia. The aim of this study was to investigate the efficacy of minimal residual disease (MRD)-guided, time-limited ibrutinib plus venetoclax treatment in this patient group. Methods: HOVON141/VISION was an open-label, randomised, phase 2 trial conducted in 47 hospitals in Belgium, Denmark, Finland, the Netherlands, Norway, and Sweden. Eligible participants were aged 18 years or older with previously treated chronic lymphocytic leukaemia with or without TP53 aberrations; had not been exposed to Bruton tyrosine-kinase inhibitors or BCL2 inhibitors; had a creatinine clearance rate of 30 mL/min or more; and required treatment according to International Workshop on Chronic Lymphocytic Leukemia 2018 criteria. Participants with undetectable MRD (10−2) during observation reinitiated treatment with ibrutinib plus venetoclax. The primary endpoint was progression-free survival at 12 months after random assignment in the treatment cessation group. Progression-free survival was analysed in the intention-to-treat population. All patients who received at least one dose of study drug were included in the safety assessment. The study is registered at ClinicalTrials.gov, NCT03226301, and is active but not recruiting. Findings: Between July 12, 2017, and Jan 21, 2019, 230 patients were enrolled, 225 of whom were eligible. 188 (84%) of 225 completed treatment with ibrutinib plus venetoclax and were tested for MRD at cycle 15. After cycle 15, 78 (35%) patients had undetectable MRD and 72 (32%) were randomly assigned to a treatment group (24 to ibrutinib maintenance and 48 to treatment cessation). The remaining 153 patients were not randomly assigned and continued with ibrutinib monotherapy. Median follow-up of 208 patients still alive and not lost to follow-up at data cutoff on June 22, 2021, was 34·4 months (IQR 30·6–37·9). Progression-free survival after 12 months in the treatment cessation group was 98% (95% CI 89–100). Infections (in 130 [58%] of 225 patients), neutropenia (in 91 [40%] patients), and gastrointestinal adverse events (in 53 [24%] patients) were the most frequently reported; no new safety signals were detected. Serious adverse events were reported in 46 (40%) of 116 patients who were not randomly assigned and who continued ibrutinib maintenance after cycle 15, eight (33%) of 24 patients in the ibrutinib maintenance group, and four (8%) of 48 patients in the treatment cessation group. One patient who was not randomly assigned had a fatal adverse event (bleeding) deemed possibly related to ibrutinib. Interpretation: These data point to a favourable benefit–risk profile of MRD-guided, time-limited treatment with ibrutinib plus venetoclax for patients with relapsed or refractory chronic lymphocytic leukaemia, suggesting that MRD-guided cessation and reinitiation is feasible in this patient population. Funding: AbbVie and Janssen

Activity of venetoclax in patients with relapsed or refractory chronic lymphocytic leukaemia: analysis of the VENICE-1 multicentre, open-label, single-arm, phase 3b trial

Background: Most patients with chronic lymphocytic leukaemia progress after treatment or retreatment with targeted therapy or chemoimmunotherapy and have limited subsequent treatment options. Response levels to the single-agent venetoclax in the relapsed setting is unknown. We aimed to assess venetoclax activity in patients with or without previous B-cell receptor-associated kinase inhibitor (BCRi) treatment. Methods: This multicentre, open-label, single-arm, phase 3b trial (VENICE-1) assessed activity and safety of venetoclax monotherapy in adults with relapsed or refractory chronic lymphocytic leukaemia, stratified by previous exposure to a BCRi. Eligible participants were aged 18 years or older with previously treated relapsed or refractory chronic lymphocytic leukaemia. Presence of del(17p) or TP53 aberrations and previous BCRi treatment were permitted. Patients received 5-week ramp-up to 400 mg of oral venetoclax once daily and were treated for up to 108 weeks, with 2 years follow-up after discontinuation, or optional extended access. The primary activity endpoint was complete remission rate (complete remission or complete remission with incomplete marrow recovery) in BCRi-naive patients. Analyses used the intent-to-treat (ie, all enrolled patients, which coincided with those who received at least one dose of venetoclax). This study was registered with ClinicalTrials.gov, NCT02756611, and is complete. Findings: Between June 22, 2016, and March 11, 2022, we enrolled 258 patients with relapsed or refractory chronic lymphocytic leukaemia (180 [70%] were male; 252 [98%] were White; 191 were BCRi-naive and 67 were BCRi-pretreated). Median follow-up in the overall cohort was 49·5 months (IQR 47·2–54·1), 49·2 months (47·2–53·2) in the BCRi-naive group, and 49·7 months (47·4–54·3) in the BCRi-pretreated group. Of 191 BCRi-naive patients, 66 (35%; 95% CI 27·8−41·8) had complete remission or complete remission with incomplete marrow recovery. 18 (27%; 95% CI 16·8–39·1) of 67 patients in the BCRi-pretreated group had complete remission or complete remission with incomplete marrow recovery. Grade 3 or worse treatment-emergent adverse events were reported in 203 (79%) and serious adverse events were reported in 136 (53%) of 258 patients in the overall cohort. The most common treatment-emergent adverse event was neutropenia (96 [37%]) and the most common and serious adverse event was pneumonia (21 [8%]). There were 13 (5%) deaths reported due to adverse events; one of these deaths (autoimmune haemolytic anaemia) was possibly related to venetoclax. No new safety signals were identified. Interpretation: These data demonstrate deep and durable responses with venetoclax monotherapy in patients with relapsed or refractory chronic lymphocytic leukaemia, including BCRi-pretreated patients, suggesting that venetoclax monotherapy is an effective strategy for treating BCRi-naive and BCRi-pretreated patients. Funding: AbbVie