Targeting Molecular Measurable Residual Disease and Low-Blast Relapse in AML With Venetoclax and Low-Dose Cytarabine: A Prospective Phase II Study (VALDAC).

PURPOSE: A prospective phase II study examined the safety and efficacy of venetoclax combined with low-dose cytarabine (LDAC) in AML at first measurable residual disease (MRD) or oligoblastic relapse. METHODS: Patients with either MRD (≥1 log10 rise) or oligoblastic relapse (blasts 5%-15%) received venetoclax 600 mg once daily D1-28 plus LDAC once daily D1-10 in 28-day cycles. The primary objective was MRD response in the MRD relapse cohort or complete remission (CR/CRh/CRi) in the oligoblastic relapse cohort. RESULTS: Forty-eight adults with either MRD (n = 26) or oligoblastic (n = 22) relapse were enrolled. Median age was 67 years (range, 18-80) and 94% had received previous intensive chemotherapy. Patients received a median of four cycles of therapy; 17% completed ≥12 cycles. Patients with oligoblastic relapse had more grade ≥3 anemia (32% v 4%; P = .02) and infections (36% v 8%; P = .03), whereas grade 4 neutropenia (32 v 23%) or thrombocytopenia (27 v 15%) were comparable with the MRD relapse cohort. Markers of molecular MRD relapse included mutant NPM1 (77%), CBFB::MYH11 (4%), RUNX1::RUNX1T1 (4%), or KMT2A::MLLT3 (4%). Three patients with a log10 rise in IDH1/2 (12%) were included. By cycle 2 in the MRD relapse cohort, a log10 reduction in MRD was observed in 69%; 46% achieved MRD negative remission. In the oligoblastic relapse cohort, 73% achieved CR/CRh/CRi. Overall, 21 (44%) underwent hematopoietic cell transplantation. Median overall survival (OS) was not reached in either cohort. Estimated 2-year OS rate was 67% (95% CI, 50 to 89) in the MRD and 53% (95% CI, 34 to 84) in the oligoblastic relapse cohorts. CONCLUSION: For AML in first remission and either MRD or oligoblastic relapse, venetoclax plus LDAC is well tolerated and highly effective.

Molecular MRD is strongly prognostic in patients with NPM1-mutated AML receiving venetoclax-based nonintensive therapy.

ABSTRACT: Assessment of measurable residual disease (MRD) by quantitative reverse transcription polymerase chain reaction is strongly prognostic in patients with NPM1-mutated acute myeloid leukemia (AML) treated with intensive chemotherapy; however, there are no data regarding its utility in venetoclax-based nonintensive therapy, despite high efficacy in this genotype. We analyzed the prognostic impact of NPM1 MRD in an international real-world cohort of 76 previously untreated patients with NPM1-mutated AML who achieved complete remission (CR)/CR with incomplete hematological recovery following treatment with venetoclax and hypomethylating agents (HMAs) or low-dose cytarabine (LDAC). A total of 44 patients (58%) achieved bone marrow (BM) MRD negativity, and a further 14 (18%) achieved a reduction of ≥4 log10 from baseline as their best response, with no difference between HMAs and LDAC. The cumulative rates of BM MRD negativity by the end of cycles 2, 4, and 6 were 25%, 47%, and 50%, respectively. Patients achieving BM MRD negativity by the end of cycle 4 had 2-year overall of 84% compared with 46% if MRD was positive. On multivariable analyses, MRD negativity was the strongest prognostic factor. A total of 22 patients electively stopped therapy in BM MRD-negative remission after a median of 8 cycles, with 2-year treatment-free remission of 88%. In patients with NPM1-mutated AML attaining remission with venetoclax combination therapies, NPM1 MRD provides valuable prognostic information.

Reproducible Bioinformatics Analysis Workflows for Detecting IGH Gene Fusions in B-Cell Acute Lymphoblastic Leukaemia Patients.

B-cell acute lymphoblastic leukaemia (B-ALL) is characterised by diverse genomic alterations, the most frequent being gene fusions detected via transcriptomic analysis (mRNA-seq). Due to its hypervariable nature, gene fusions involving the Immunoglobulin Heavy Chain (IGH) locus can be difficult to detect with standard gene fusion calling algorithms and significant computational resources and analysis times are required. We aimed to optimize a gene fusion calling workflow to achieve best-case sensitivity for IGH gene fusion detection. Using Nextflow, we developed a simplified workflow containing the algorithms FusionCatcher, Arriba, and STAR-Fusion. We analysed samples from 35 patients harbouring IGH fusions (IGH::CRLF2 n = 17, IGH::DUX4 n = 15, IGH::EPOR n = 3) and assessed the detection rates for each caller, before optimizing the parameters to enhance sensitivity for IGH fusions. Initial results showed that FusionCatcher and Arriba outperformed STAR-Fusion (85-89% vs. 29% of IGH fusions reported). We found that extensive filtering in STAR-Fusion hindered IGH reporting. By adjusting specific filtering steps (e.g., read support, fusion fragments per million total reads), we achieved a 94% reporting rate for IGH fusions with STAR-Fusion. This analysis highlights the importance of filtering optimization for IGH gene fusion events, offering alternative workflows for difficult-to-detect high-risk B-ALL subtypes.

Invasive fungal infection following venetoclax and posaconazole co-administration.

The co-administration of venetoclax, a BCL-2 inhibitor, with a mould-active azole, such a posaconazole, has potential to both prevent invasive fungal infection (IFI) and reduce the required treatment dose, and cost, of venetoclax. Posaconazole drug-level monitoring is critical to ensuring adequate mould prophylaxis. A retrospective audit of 99 patients at a tertiary cancer centre, with myeloid malignancies co-prescribed venetoclax and posaconazole between January 2018 and April 2022, was undertaken to evaluate the adequacy of posaconazole prescribing and the rate of breakthrough IFI. Seventy-six patients (77%) had at least one posaconazole level measured in the study period, with 37% requiring a dose adjustment based on steady-state trough levels. Breakthrough IFI occurred in 4% of patients, typically within 1 month of commencing anti-mould prophylaxis. Close monitoring of posaconazole levels in venetoclax-treated patients, particularly in the early, outpatient setting, is critical.

Outcomes of non-myeloablative allogeneic stem cell transplant in older patients with acute myeloid leukaemia in first remission.

The benefits of non-myeloablative stem cell transplant in older patients with acute myeloid leukaemia are unclear. We compare the long-term outcomes of this regimen in those aged 55-65 years in first remission with a chemotherapy only cohort that achieved durable morphologic remission. Five-year overall survival was similar (32% vs 33%, P = 0.90), as was relapse-free survival (23% vs 20%, P = 0.37). There was a trend for decreased relapse that was balanced against increased non-relapse mortality with transplantation.

Treatment practice and outcomes in FLT3-mutant acute myeloid leukemia in the pre-midostaurin era: a real-world experience from Australian tertiary hospitals.

Recent regulatory approval of midostaurin, a FLT3 targeting small molecular inhibitor, will likely lead to increased use of midostaurin in combination with intensive chemotherapy for patients with FLT3-mutant AML. Translation of clinical trial results into everyday practice has its challenges. This study compared the relevance of the trial population and practices studied in the midostaurin registration study (RATIFY) with real-world practice in terms of patient factors, chemotherapy, mutation-specific frequencies and clinical outcomes among patients with FLT3-mutant AML in the pre-midostaurin era (2010-2015) in Australia. We observed substantial diversity of chemotherapy regimens used in the community and limitations of the generalizability of eligibility criteria used in RATIFY (such as age and hyperleukocytosis). This study provides real-world historical data that may be used for comparison with future trial cohorts incorporating FLT3 inhibitors into the management of FLT3-mutant AML and highlights the inherent difficulties in translating clinical trial data into routine practice.

Acute myeloid leukaemia relapsing after allogeneic haemopoietic stem cell transplantation: prognostic factors and impact of initial therapy of relapse.

BACKGROUND/AIMS: We sought to determine factors associated with the overall survival from relapse (OSR) of acute myeloid leukaemia (AML) after allogeneic haemopoietic stem cell transplantation (alloHSCT) and the effect of first salvage therapy and subsequent graft-versus-host disease (GVHD) on OSR. METHODS: Data on 386 patients from nine Australian centres with relapsed AML post-alloHSCT were collected retrospectively. OSR was calculated using the Kaplan-Meier method. Univariate and multivariate analyses were conducted using the log-rank test and proportional hazards modelling, respectively and a prognostic index for OSR was derived from multivariate modelling. RESULTS: On multivariate analysis, relapse within 6 months (hazard ratio (HR) 2.4, P < 0.001) and grade 3-4 acute GVHD preceding relapse (HR 2.0, P = 0.004), were associated with inferior OSR. Patients with 1-2 factors had inferior OSR compared to those with zero factors (all patients: HR 2.3, P < 0.001, patients given salvage: HR 1.8, P < 0.001). The first salvage therapy used post-relapse was donor cell therapy (DCT) (second alloHSCT or donor lymphocyte infusion) in 75, re-induction chemotherapy (CT) in 103, radiotherapy in 8 and interferon-α in 6. Although re-induction CT death rate was low (2%), survival after CT was inferior to DCT (HR 1.9, P < 0.001). No survival benefit was seen for patients who developed GVHD following salvage therapy (P = 0.405). CONCLUSION: Patients with AML who relapse beyond 6 months from alloHSCT without prior grade 3-4 acute GVHD have a better outcome from salvage therapy. Salvage treatments employing DCT as the initial treatment of AML relapse confer a survival advantage over CT.