Better the cure you know: why patients with AML ≥60 years of age should be offered early allogeneic stem cell transplantation

Lower intensity therapy with cladribine/low dose cytarabine/venetoclax in older patients with acute myeloid leukemia compares favorably with intensive chemotherapy among patients undergoing allogeneic stem cell transplantation

BACKGROUND

Allogeneic stem cell transplantation (SCT) remains the best consolidative modality in most patients with acute myeloid leukemia (AML). Along with factors directly pertaining to SCT, pretransplantation disease control, performance status, and prior treatment-related complications are important factors that affect posttransplantation survival outcomes.

METHODS

The authors compared the survival outcomes of patients ≥60 years of age treated on the phase 2 clinical trial of venetoclax (Ven) added to cladribine (CLAD) and low dose cytarabine (LDAC) alternating with azacitidine (CLAD/LDAC/Ven arm) (NCT03586609) who underwent allogeneic SCT in first remission to a retrospective cohort of patients ≥60 years of age who underwent SCT after intensive chemotherapy. Intensive chemotherapy was defined as the use of cytarabine >1 g/m2 and anthracyclines during induction/consolidation.

RESULTS

Thirty-five patients at median age of 68 years in the CLAD/LDAC/Ven arm were compared to 42 patients at a median age of 62 years in the intensive therapy arm. The 2-year relapse-free survival was superior with CLAD/LDAC/Ven versus intensive chemotherapy (88% vs. 65%; p = .03) whereas the 2-year overall survival (OS) was comparable (84% vs. 70%; p = .14). On a competing event analysis, the 2-year cumulative incidence of relapse (CIR) was significantly lower with CLAD/LDAC/Ven versus intensive chemotherapy (2.9% vs. 17.2%, Gray's p = .049) whereas nonrelapse mortality was comparable (16.2% vs. 17.1%; p = .486).

CONCLUSION

In conclusion, treatment with CLAD/LDAC/Ven was associated with favorable outcomes in older patients who underwent subsequent allogeneic SCT. The OS was comparable to that with intensive chemotherapy followed by allogeneic SCT, but the CIR rate was significantly lower.

Randomized Phase III SIERRA Trial of 131I-Apamistamab Before Allogeneic Hematopoietic Cell Transplantation Versus Conventional Care for Relapsed/Refractory AML

PURPOSE

Older patients with relapsed or refractory AML (RR AML) have dismal prognoses without allogeneic hematopoietic cell transplantation (alloHCT). SIERRA compared a targeted pretransplant regimen involving the anti-CD45 radioconjugate 131I-apamistamab with conventional care.

METHODS

SIERRA (ClinicalTrials.gov identifier: NCT02665065) was a phase III open-label trial. Patients age ≥55 years with active RR AML were randomly assigned 1:1 to either an 131I-apamistamab-led regimen before alloHCT or conventional care followed by alloHCT if initial complete remission (CR)/CR with incomplete platelet recovery (CRp) occurred. Initial response was assessed 28-56 days after alloHCT in the 131I-apamistamab group and 28-42 days after salvage chemotherapy initiation; patients without CR/CRp or with AML progression could cross over to receive 131I-apamistamab followed by alloHCT. The primary end point was durable complete remission (dCR) lasting 180 days after initial CR/CRp. Secondary end points were overall survival (OS) and event-free survival (EFS), assessed hierarchically in the intention-to-treat (ITT) population.

RESULTS

The ITT population included 153 patients (131I-apamistamab [n = 76]; conventional care [n = 77]). In total, 44/77 conventional care arm patients crossed over and 40/77 (52%) received 131I-apamistamab and alloHCT, with six patients (13.6%) experiencing a dCR. In the ITT population, the dCR rate was significantly higher with 131I-apamistamab (17.1% [95% CI, 9.4 to 27.5]) than conventional care (0% [95% CI, 0 to 4.7]; P < .0001). The OS hazard ratio (HR) was 0.99 (95% CI, 0.70 to 1.41; P = .96), and the EFS HR was 0.23 (95% CI, 0.15 to 0.34), with HR <1 favoring 131I-apamistamab. Grade ≥3 treatment-related adverse events occurred in 59.7% and 59.2% of the 131I-apamistamab and conventional care groups, respectively.

CONCLUSION

The 131I-apamistamab-led regimen was associated with a higher dCR rate than conventional care in older patients with RR AML. 131I-apamistamab was well tolerated and could address an unmet need in this population.

Venetoclax-based treatment in acute myeloid leukemia: an unexpected bonus on the path to allogeneic hematopoietic stem cell transplant?

Despite the approval of new drugs, the inclusion of -omics-derived data and the integration of machine learning in both the diagnostic and therapeutic process, the prognosis of acute myeloid leukemia (AML) remains dismal. The curative path is still aimed at achieving a successful allogeneic hematopoietic stem cell transplant (HSCT) in most patients. Nevertheless, access to this procedure is limited to eligible patients. Moreover, post-HSCT outcomes are influenced by AML heterogeneity and patient-related factors. The rise of venetoclax (VEN)-based combinations as standard of care in the treatment of older or unfit AML patients, together with their peculiar management profile, has led researchers to evaluate the feasibility of this approach in patients proceeding toward HSCT. We reviewed the available evidence to weigh up the advantages and pitfalls of this new therapeutic strategy.

Current knowledge about FLT3 gene mutations, exploring the isoforms, and protein importance in AML

Acute myeloid leukaemia (AML) is a complex haematological malignancy characterised by diverse genetic alterations leading to abnormal proliferation of myeloid precursor cells. One of the most significant genetic alterations in AML involves mutations in the FLT3 gene, which plays a critical role in haematopoiesis and haematopoietic homeostasis. This review explores the current understanding of FLT3 gene mutations and isoforms and the importance of the FLT3 protein in AML. FLT3 mutations, including internal tandem duplications (FLT3-ITD) and point mutations in the tyrosine kinase domain (FLT3-TKD), occur in 25-30% in AML and are associated with poor prognosis. FLT3-ITD mutations lead to constitutive activation of the FLT3 signalling pathway, promoting cell survival and proliferation. FLT3-TKD mutations affect the tyrosine kinase domain and affect AML prognosis in various ways. Furthermore, FLT3 isoforms, including shorter variants, contribute to the complexity of FLT3 biology. Additionally, nonpathological polymorphisms in FLT3 are being explored for their potential impact on AML prognosis and treatment response. This review also discusses the development of molecular treatments targeting FLT3, including first-generation and next-generation tyrosine kinase inhibitors, highlighting the challenges of resistance that often arise during therapy. The final chapter describes FLT3 protein domain rearrangements and their relevance to AML pathogenesis.

Older Adults With Newly Diagnosed AML: Hot Topics for the Practicing Clinician

Over the past decade, our understanding of AML pathogenesis and pathophysiology has improved significantly with mutational profiling. This has led to translational advances in therapeutic options, as there have been 10 new US Food and Drug Administration (FDA) approvals for AML therapies since 2017, half of which target specific driver mutations in FLT3, IDH1, or IDH2. These new agents have expanded the therapeutic armamentarium for AML, particularly for patients who are considered ineligible for intensive chemotherapy with anthracycline- and cytarabine-containing regimens. These new treatment options are relevant because the median age at diagnosis is 68 years, and outcomes for patients older than 60 years have historically been dismal. However, the optimal approach to incorporating novel agents into frontline regimens remains a clinical challenge, particularly with regard to sequencing of therapies, considering the role of allogeneic hematopoietic stem cell transplantation and managing toxicities.

Azacitidine Post-Remission Therapy for Elderly Patients with AML: A Randomized Phase-3 Trial (QoLESS AZA-AMLE)

This phase-3 randomized multicenter trial evaluated the efficacy of subcutaneous azacitidine (AZA) post-remission therapy vs. best supportive care (BSC) in elderly acute myeloid leukemia (AML) patients. The primary endpoint was the difference in disease-free survival (DFS) from complete remission (CR) to relapse/death. Patients with newly diagnosed AML aged ≥61 years received two courses of induction chemotherapy ("3+7" daunorubicin and cytarabine) followed by consolidation (cytarabine). At CR, 54 patients were randomized (1:1) to receive BSC (N = 27) or AZA (N = 27) at a dose of 50 mg/m² for 7 days every 28 days and the dose increased after the 1st cycle to 75 mg/m² for a further 5 cycles, followed by cycles every 56 days for 4.5 years. At 2 years, median DFS was 6.0 (95% CI: 0.2-11.7) months for patients receiving BSC vs. 10.8 months (95% CI: 1.9-19.6, p = 0.20) months for AZA. At 5 years, DFS was 6.0 (95% CI: 0.2-11.7) months in the BSC arm vs. 10.8 (95% CI: 1.9-19.6, p = 0.23) months in the AZA arm. Significant benefit was afforded by AZA on DFS at 2 and 5 years in patients aged >68 years (HR = 0.34, 95% CI: 0.13-0.90, p = 0.030 and HR = 0.37, 95% CI: 0.15-0.93, p = 0.034, respectively). No deaths occurred prior to leukemic relapse. Neutropenia was the most frequent adverse event. There were no differences in patient-reported outcome measures between study arms. In conclusion, AZA post-remission therapy was found to provide benefit in AML patients aged >68 years.

Gene mutation analysis using next-generation sequencing and its clinical significance in patients with myeloid neoplasm: A multi-center study from China

BACKGROUND

Myeloid neoplasms (MN) tend to relapse and deteriorate. Exploring the genomic mutation landscape of MN using next-generation sequencing (NGS) is a great measure to clarify the mechanism of oncogenesis and progression of MN.

METHODS

This multicenter retrospective study investigated 303 patients with MN using NGS from 2019 to 2021. The characteristics of the mutation landscape in the MN subgroups and the clinical value of gene variants were analyzed.

RESULTS

At least one mutation was detected in 88.11% of the patients (267/303). TET2 was the most common mutation in the cohort, followed by GATA2, ASXL1, FLT3, DNMT3A, and TP53. Among patients with myeloid leukemia (ML), multivariate analysis showed that patients aged ≥60 years had lower overall survival (OS, p = 0.004). Further analysis showed TET2, NPM1, SRSF2, and IDH1 gene mutations, and epigenetic genes (p < 0.050) presented significantly higher frequency in older patients. In patients with myelodysplastic syndrome (MDS) and myelodysplastic neoplasms (MPN), univariate analysis showed that BCORL1 had a significant impact on OS (p = 0.040); however, in multivariate analysis, there were no factors significantly associated with OS. Differential analysis of genetic mutations showed FLT3, TP53, MUC16, SRSF2, and KDM5A mutated more frequently (p < 0.050) in secondary acute myeloid leukemia (s-AML) than in MDS and MPN. TP53, U2AF1, SRSF2, and KDM5A were mutated more frequently (p < 0.050) in s-AML than in primary AML. KDM5A was observed to be restricted to patients with s-AML in this study, and only co-occurred with MUC16 and TP53 (2/2, 100%). Another mutation was MUC16, and its co-occurrence pattern differed between s-AML and AML. MUC16 mutations co-occurred with KDM5A and TP53 in 66.7% (2/3) of patients with s-AML and co-occurred with CEBPA in 100% (4/4) of patients with AML.

CONCLUSIONS

Our results demonstrate different genomic mutation patterns in the MN subgroups and highlight the clinical value of genetic variants.