Survival is poorer in patients with secondary core-binding factor acute myelogenous leukemia compared with de novo core-binding factor leukemia

Adult rhabdomyosarcoma combined with acute myeloid leukemia: A case report

BACKGROUND

Rhabdomyosarcoma is a tumor of mesenchymal origin. Secondary leukemia is a complication of previous transformation to other hematologic disorders or is a treatment-related acute myeloid leukemia secondary to cytotoxic chemotherapy or radiation therapy for other malignancies.

CASE SUMMARY

We present the case of a 36-year-old female patient who was diagnosed with rhabdomyosarcoma and acute myeloid leukemia. Further disease progression was observed after multiline chemotherapy. Eventually, the patient suffered cerebral hemorrhage, which resulted in death.

CONCLUSION

The incidence of rhabdomyosarcoma in adults is extremely low, and secondary leukemia caused by rhabdomyosarcoma is even rarer. Secondary leukemia has a very poor prognosis and a low overall survival rate.

Acute Myeloid Leukemia Arising from Myelodysplastic Syndromes

Myelodysplastic syndromes (MDS) are a group of myeloid neoplasms characterized by clonal hematopoiesis and abnormal maturation of hematopoietic cells, resulting in cytopenias. The transformation of MDS to acute myeloid leukemia (AML) reflects a progressive increase in blasts due to impaired maturation of the malignant clone, and thus MDS and many AML subtypes form a biological continuum rather than representing two distinct diseases. Recent data suggest that, in addition to previously described translocations, NPM1 mutations and KMT2A rearrangements are also AML-defining genetic alterations that lead to rapid disease progression, even if they present initially with less than  20% blasts. While some adult patients <20% blasts can be treated effectively with intensive AML-type chemotherapy, in the future, treatment of individual patients in this MDS/AML group will likely be dictated by genetic, biological, and patient-related factors rather than an arbitrary blast percentage.

The core concepts of core binding factor acute myeloid leukemia: Current considerations for prognosis and treatment

Core binding factor acute myeloid leukemia (CBF AML), defined by t(8;21) or inv(16), is a subset of favorable risk AML. Despite its association with a high complete remission rate after induction and relatively good prognosis overall compared with other subtypes of AML, relapse risk after induction chemotherapy remains high. Optimizing treatment planning to promote recurrence free survival and increase the likelihood of survival after relapse is imperative to improving outcomes. Recent areas of research have included evaluation of the role of gemtuzumab in induction and consolidation, the relative benefit of increased cycles of high dose cytarabine in consolidation, the utility of hypomethylating agents and kinase inhibitors, and the most appropriate timing of stem cell transplant. Surveillance with measurable residual disease testing is increasingly being utilized for monitoring disease in remission, and ongoing investigation seeks to determine how to use this tool for early identification of patients who would benefit from proceeding to transplant. In this review, we outline the current therapeutic approach from diagnosis to relapse while highlighting the active areas of investigation in each stage of treatment.

NPM1-mutated acute myeloid leukemia: New pathogenetic and therapeutic insights and open questions

The nucleophosmin (NPM1) gene encodes for a multifunctional chaperone protein that is localized in the nucleolus but continuously shuttles between the nucleus and cytoplasm. NPM1 mutations occur in about one-third of AML, are AML-specific, usually involve exon 12 and are frequently associated with FLT3-ITD, DNMT3A, TET2, and IDH1/2 mutations. Because of its unique molecular and clinico-pathological features, NPM1-mutated AML is regarded as a distinct leukemia entity in both the International Consensus Classification (ICC) and the 5th edition of the World Health Organization (WHO) classification of myeloid neoplasms. All NPM1 mutations generate leukemic mutants that are aberrantly exported in the cytoplasm of the leukemic cells and are relevant to the pathogenesis of the disease. Here, we focus on recently identified functions of the NPM1 mutant at chromatin level and its relevance in driving HOX/MEIS gene expression. We also discuss yet controversial issues of the ICC/WHO classifications, including the biological and clinical significance of therapy-related NPM1-mutated AML and the relevance of blasts percentage in defining NPM1-mutated AML. Finally, we address the impact of new targeted therapies in NPM1-mutated AML with focus on CAR T cells directed against NPM1/HLA neoepitopes, as well as XPO1 and menin inhibitors.

Single-center phase 2 study of PD-1 inhibitor combined with DNA hypomethylation agent + CAG regimen in patients with relapsed/refractory acute myeloid leukemia

Anti-PD-1 monotherapy had limited clinical efficacy in relapsed/refractory (r/r) AML patients with higher PD-1 and PD-L1 expression. Hence, we investigated the efficacy and safety of PD-1 inhibitor with DNA hypomethylating agent (HMA) + CAG regimen in patients who had failed prior AML therapy. In this phase 2, single-arm study, r/r AML patients received azacitidine or decitabine plus CAG regimen with tislelizumab. Primary endpoints were efficacy (objective response rate [ORR]) and safety. Secondary endpoints included overall survival (OS), event-free survival (EFS) and duration of response (DOR). Statistical analyses were performed using Stata 14.0 and SPSS 20.0 software where P < 0.05 denoted significance. Twenty-seven patients were enrolled patients and completed 1 cycle, and 14 (51.9%) and 4 (14.8%) patients completed 2 and 3 cycles, respectively. ORR was 63% (14: complete remission [CR]/CR with incomplete hematologic recovery [CRi], 3: partial remission (PR), 10: no response [NR]). Median OS (mOS) and EFS were 9.7 and 9.2 months, respectively. With a median follow-up of 8.2 months (1.1-26.9), the mOS was not reached in responders (CR/CRi/PR) while it was 2.4 months (0.0-5.4) in nonresponders (P = 0.002). Grade 2-3 immune-related adverse events (irAEs) were observed in 4 (14.8%) patients and 3 nonresponders died of lung infection after treatment. Tislelizumab + HMA + CAG regimen showed improved outcomes in r/r AML patients with lower pretherapy leukemia burden. irAEs were mild and low-grade and higher pretherapy bone marrow CD4⁺ CD127⁺ PD-1⁺ T cells might serve as a predictor of treatment response.ClinicalTrials.gov identifier NCT04541277.

Overlapping features of therapy-related and de novo NPM1-mutated AML

NPM 1-mutated acute myeloid leukemia (AML) shows unique features. However, the characteristics of "therapy-related" NPM1-mutated AML (t-NPM1 AML) are poorly understood. We compared the genetics, transcriptional profile, and clinical outcomes of t-NPM1 AML, de novo NPM1-mutated AML (dn-NPM1 AML), and therapy-related AML (t-AML) with wild-type NPM1 (t-AML). Normal karyotype was more frequent in t-NPM1 AML (n = 78/96, 88%) and dn-NPM1 (n = 1986/2394, 88%) than in t-AML (n = 103/390, 28%; P < .001). DNMT3A and TET2 were mutated in 43% and 40% of t-NPM1 AML (n = 107), similar to dn-NPM1 (n = 88, 48% and 30%; P > 0.1), but more frequently than t-AML (n = 162; 14% and 10%; P < 0.001). Often mutated in t-AML, TP53 and PPM1D were wild-type in 97% and 96% of t-NPM1 AML, respectively. t-NPM1 and dn-NPM1 AML were transcriptionally similar, (including HOX genes upregulation). At 62 months of median follow-up, the 3-year overall survival (OS) for t-NPM1 AML (n = 96), dn-NPM1 AML (n = 2394), and t-AML (n = 390) were 54%, 60%, and 31%, respectively. In multivariable analysis, OS was similar for the NPM1-mutated groups (hazard ratio [HR] 0.9; 95% confidence interval [CI], 0.65-1.25; P = .45), but better in t-NPM1 AML than in t-AML (HR, 1.86; 95% CI, 1.30-2.68; P < .001). Relapse-free survival was similar between t-NPM1 and dn-NPM1 AML (HR, 1.02; 95% CI, 0.72-1.467; P = .90), but significantly higher in t-NPM1 AML versus t-AML (HR, 1.77; 95% CI, 1.19-2.64; P = .0045). t-NPM1 and dn-NPM1 AML have overlapping features, suggesting that they should be classified as a single disease entity.

Updates in molecular genetics of therapy-related myeloid neoplasms

Therapy-related myeloid neoplasms (t-MN) are a heterogeneous group of aggressive myeloid neoplasms that arise following exposure to various cytotoxic therapeutic agents and/or ionizing radiation for treatment of prior non-myeloid malignancy or autoimmune disease. Each therapeutic group has been associated with varying latency intervals from the time of therapy exposure to onset of t-MN, as well as certain recurrent genetic alterations. This review will focus on the molecular genetic alterations that have been described in t-MNs, as well as recent updates regarding diagnostic classification.

Therapy-related core binding factor acute myeloid leukemia

Therapy-related acute myeloid leukemia (t-AML) usually stems from exposure of the bone marrow to cytotoxic chemotherapy and/or radiation therapy. t-AML is usually associated with poor overall survival, but occasionally t-AML can involve favorable-risk cytogenetics, including core binding factor AML (CBF-AML), which shows a recurrent chromosomal rearrangement with t(8;21) (q22;22) and 'inv(16) (p13.1;q22)/t(16;16)(p13.1;q22)', leading to 'RUNX1::RUNX1T1 and CBFB::MYH11' fusion genes, respectively. Therapy-related CBF-AML (t-CBF-AML) accounts for 5-15% of CBF-AML cases and tends to have better outcomes than t-AML with unfavorable cytogenetics. Although CBF-AML is sensitive to high-dose cytarabine, t-CBF-AML has worse overall survival than de novo CBF- AML. The objective of this review is to discuss the available data on the pathogenesis, mutations, and therapeutic options in patients with t-CBF-AML.

Convergent Clonal Evolution of Signaling Gene Mutations Is a Hallmark of Myelodysplastic Syndrome Progression

Progression from myelodysplastic syndromes (MDS) to secondary acute myeloid leukemia (AML) is associated with the acquisition and expansion of subclones. Our understanding of subclone evolution during progression, including the frequency and preferred order of gene mutation acquisition, remains incomplete. Sequencing of 43 paired MDS and secondary AML samples identified at least one signaling gene mutation in 44% of MDS and 60% of secondary AML samples, often below the level of standard sequencing detection. In addition, 19% of MDS and 47% of secondary AML patients harbored more than one signaling gene mutation, almost always in separate, coexisting subclones. Signaling gene mutations demonstrated diverse patterns of clonal evolution during disease progression, including acquisition, expansion, persistence, and loss of mutations, with multiple patterns often coexisting in the same patient. Multivariate analysis revealed that MDS patients who had a signaling gene mutation had a higher risk of AML progression, potentially providing a biomarker for progression.

SIGNIFICANCE

Subclone expansion is a hallmark of progression from MDS to secondary AML. Subclonal signaling gene mutations are common at MDS (often at low levels), show complex and convergent patterns of clonal evolution, and are associated with future progression to secondary AML. See related article by Guess et al., p. 316 (33). See related commentary by Romine and van Galen, p. 270. This article is highlighted in the In This Issue feature, p. 265.

Oncology stewardship in acute myeloid leukemia

In recent years, an explosion of novel agents has shifted the treatment paradigm for patients with acute myeloid leukemia. The optimal place in therapy for many of these novel agents remains unknown due to limited guidance from national guidelines and the way these agents were studied prior to entering the market. A critical evaluation of the literature and incorporation of oncology stewardship principles can be helpful in determining an optimal place for these agents while being mindful of the overall cost that is associated with therapies. The purpose of this review is to critically evaluate the efficacy and safety data for five controversial agents and provide examples of the use of stewardship practices in determining their place in the treatment of acute myeloid leukemia.

Activity of decitabine as maintenance therapy in core binding factor acute myeloid leukemia

Background

Posttherapy measurable residual disease (MRD) positivity in core binding factor acute myeloid leukemia (CBF‐AML) is associated with shorter relapse‐free survival (RFS). Elimination of MRD measured via quantitative reverse transcription polymerase chain reaction (qRTPCR) for disease specific transcripts can potentially lead to better outcomes in CBF‐AML.

Methods

We prospectively monitored the MRD using qRTPCR and flow cytometry on bone marrow samples in patients with newly diagnosed CBF‐AML who received decitabine (DAC) maintenance therapy after fludarabine/cytarabine/G‐CSF (FLAG)‐based induction/consolidation regimen. Negative qRTPCR (CMR) was defined as fusion transcript <0.01%.

Results

Thirty‐one patients with CBF‐AML including 14 with t(8;21) and 17 with inv(16) received parenteral DAC as maintenance therapy. Fifteen patients (48.3%) had completed FLAG‐based induction/consolidation but with positive MRD (0.35%, range = 0.01%–0.91%) (Group 1). Sixteen patients (51.7%) could not complete recommended consolidations with FLAG‐based regimen (due to older age or complications) and were switched to DAC maintenance (Group 2). In Group 2, eight patients (50%) had undetectable MRD (Group 2A) (all had qRTPCR ≤ 0.01%) and the other eight patients (50%) had residual fusion product by qRTPCR (0.1%, range = 0.02%–0.36%) (Group 2B) prior to starting DAC. Amongst the 23 patients who had a PCR ≥ 0.01% before maintenance therapy (Groups 1 and 2B), 12 patients (52%) attained a CMR as their best response (responders). The median pre‐DAC qRTPCR amongst responders were 0.03% compared to 0.14% in nonresponders (p = .002). The median estimated molecular RFS amongst responders were 93.9 months. At a median follow‐up of 59.3 months (13.2–106 months) from DAC initiation, 16 patients (51.6%) had to be initiated on a second line of therapy (40%, 25%, and 100% patients, respectively, in Groups1, 2A, and 2B). The median estimated time to new treatment between responders was 112.4 versus 5.8 months in nonresponders (hazard ratio = 0.16, 95% confidence interval = 0.04–0.54); however, there were no difference in overall survival between these groups (p = .37).

Conclusion

DAC is an effective maintenance therapy for CBF‐AML patients with persistent fusion transcript at a low level after FLAG‐based regimen. Attainment of CMR with DAC maintenance can lead to long‐term remission in patients who have persistent MRD positive after FLAG‐based regimen or are unable to receive the full course of consolidation therapy.

Allogeneic hematopoietic cell transplantation in patients with therapy-related myeloid neoplasm after breast cancer: a study of the Chronic Malignancies Working Party of the EBMT

We performed a registry study on therapy-related myeloid neoplasm (t-MN), both therapy-related myelodysplastic syndrome (t-MDS) and acute myeloid leukemia (t-AML) following treatment for breast cancer who underwent a first allogeneic hematopoietic cell transplant (allo-HCT). Of 252 identified female patients (median age 57 years), 77% were transplanted for t-AML and 23% for t-MDS, with a median time from breast cancer diagnosis to the diagnosis of tMN and subsequent allo-HCT of 3.7 and 4.6 years, respectively. At transplant, 191 patients were in remission for breast cancer, while 4 were not (57 missing). T-MN was in a complete remission at the time of transplant in 67% of patients. 2-year overall survival, relapse free-survival, relapse incidence and non-relapse mortality were 50%, 45%, 33%, and 22%, respectively. Multivariable analysis revealed that if the t-MN was not in CR pre-transplant, this was associated with lower OS, RFS, and a higher relapse incidence. Seventeen cases of breast cancer recurrence were recorded after a median of 2.4 years post-transplant, and relapse of primary breast cancer accounted for 7% of deaths. This study indicates that allo-HCT for t-MN following treatment for breast cancer shows encouraging transplant outcomes. The incidence of breast cancer relapse post-transplant remains a cause for concern.

Treatment patterns and outcomes of 2310 patients with secondary acute myeloid leukemia: a PETHEMA registry study

The large PETHEMA registry shows that secondary AML represents 27% of AML cases and confirms its independent adverse prognostic value.

Subcategories of secondary AML were analyzed, including MSD/MPN and therapy-related cases, with different features and outcomes.

Secondary acute myeloid leukemia (sAML) comprises a heterogeneous group of patients and is associated with poor overall survival (OS). We analyze the characteristics, treatment patterns, and outcomes of adult patients with sAML in the Programa Español de Tratamientos en Hematología (PETHEMA) registry. Overall, 6211 (72.9%) were de novo and 2310 (27.1%) had sAML, divided into myelodysplastic syndrome AML (MDS-AML, 44%), MDS/myeloproliferative AML (MDS/MPN-AML, 10%), MPN-AML (11%), therapy-related AML (t-AML, 25%), and antecedent neoplasia without prior chemotherapy/radiotherapy (neo-AML, 9%). Compared with de novo, patients with sAML were older (median age, 69 years), had more Eastern Cooperative Oncology Group ≥2 (35%) or high-risk cytogenetics (40%), less FMS-like tyrosine kinase 3 internal tandem duplication (11%), and nucleophosmin 1 (NPM1) mutations (21%) and received less intensive chemotherapy regimens (38%) (all P < .001). Median OS was higher for de novo than sAML (10.9 vs 5.6 months; P < .001) and shorter in sAML after hematologic disorder (MDS, MDS/MPN, or MPN) compared with t-AML and neo-AML (5.3 vs 6.1 vs 5.7 months, respectively; P = .04). After intensive chemotherapy, median OS was better among patients with de novo and neo-AML (17.2 and 14.6 months, respectively). No OS differences were observed after hypomethylating agents according to type of AML. sAML was an independent adverse prognostic factor for OS. We confirmed high prevalence and adverse features of sAML and established its independent adverse prognostic value. This trial was registered at www.clinicaltrials.gov as #NCT02607059.

Molecular and genomic landscapes in secondary & therapy related acute myeloid leukemia

Acute myeloid leukemia (AML) is a complex, aggressive myeloid neoplasm characterized by frequent somatic mutations that influence different functional categories' genes, resulting in maturational arrest and clonal expansion. AML can arise de novo (dn-AML) or can be secondary AML (s-AML) refers to a leukemic process which may arise from an antecedent hematologic disorder (AHD-AML), mostly from a myelodysplastic syndrome (MDS) or myeloproliferative neoplasm (MPN) or can be the result of an antecedent cytotoxic chemotherapy or radiation therapy (therapy-related AML, t-AML). Clinical and biological features in secondary and therapy-related AML are distinct from de novo AML. Secondary and therapy-related AML occurs mainly in the elderly population and responds worse to therapy with higher relapse rates due to resistance to cytotoxic chemotherapy. Over the last decade, advances in molecular genetics have disclosed the sub-clonal architecture of secondary and therapy-related AML. Recent investigations have revealed that cytogenetic abnormalities and underlying genetic aberrations (mutations) are likely to be significant factors dictating prognosis and critical impacts on treatment outcome. Secondary and therapy-related AML have a poorer outcome with adverse cytogenetic abnormalities and higher recurrences of unfavorable mutations compared to de novo AML. In this review, we present an overview of the clinical features of secondary and therapy-related AML and address the function of genetic mutations implicated in the pathogenesis of secondary leukemia. Detailed knowledge of the pathogenetic mechanisms gives an overview of new prognostic markers, including targetable mutations that will presumably lead to the designing and developing novel molecular targeted therapies for secondary and therapy-related AML. Despite significant advances in knowing the genetic aspect of secondary and therapy-related AML, its influence on the disease's pathophysiology, standard treatment prospects have not significantly evolved during the past three decades. Thus, we conclude this review by summarizing the modern and developing treatment strategies in secondary and therapy-related acute myeloid leukemia.

Core binding factor acute myelogenous leukemia-2021 treatment algorithm

Core binding factor acute myelogenous leukemia (CBF-AML), characterized by the presence of either t(8;21) (q22;q22) or inv(16) (p13q22)/t(16;16), is considered good-risk AML in the context of cytarabine based intensive chemotherapy. Still, outcome can be improved significantly through the effective implementation of available therapeutic measures and appropriate disease monitoring. The incorporation of gemtuzumab ozogamicin into frontline therapy should be standard. Cytarabine based induction/consolidation regimen may be combined with anthracycline (3 + 7 standard) or antimetabolite, fludarabine. Serial quantitative polymerase chain reaction (QPCR) monitoring of unique fusion transcripts allows monitoring for measurable residual disease clearance; this allows for better prognostication and well as treatment modifications.

Secondary AML Emerging After Therapy with Hypomethylating Agents: Outcomes, Prognostic Factors, and Treatment Options

PURPOSE OF REVIEW

Secondary AML (s-AML) encompasses a distinct subgroup of AML with either therapy-related AML or AML arising from preexisting myeloid neoplasms. Despite recent advances in the treatment armamentarium of AML, outcomes remain poor in s-AML. The purpose of this review is to highlight distinct characteristics, prognostic factors, and treatment options for patients with s-AML. Further, we focus on a distinctly poor-risk subgroup of s-AML with previous exposure to hypomethylating agents (HMAs) and describe ongoing clinical trials in this patient population.

RECENT FINDINGS

CPX-351 (liposomal daunorubicin and cytarabine) is the first drug approved for s-AML and represents an advancement in the management of fit patients with this subtype of AML. Despite incremental improvement in remission rates and survival, long-term survival remains poor. Patients who have received prior HMAs for antecedent MDS rarely benefit from CPX-351 or other cytotoxic chemotherapy regimens. The approval of venetoclax in combination with azacitidine has led to a paradigm shift in the management of newly diagnosed older unfit AML patients; however, patients with s-AML and prior HMA therapy were excluded from the landmark randomized phase 3 study. Several early phase clinical trials with both low- and high-intensity therapies are ongoing for s-AML patients, though prior HMA exposure limits inclusion in many of these studies that include HMAs. Patients with s-AML previously treated with an HMA have dismal outcomes with standard therapeutic options and are under-represented in clinical trials. Trials investigating novel therapeutic options in this population are critically needed.

Genetics of progression from MDS to secondary leukemia

Our understanding of the genetics of acute myeloid leukemia (AML) development from myelodysplastic syndrome (MDS) has advanced significantly as a result of next-generation sequencing technology. Although differences in cell biology and maturation exist between MDS and AML secondary to MDS, these 2 diseases are genetically related. MDS and secondary AML cells harbor mutations in many of the same genes and functional categories, including chromatin modification, DNA methylation, RNA splicing, cohesin complex, transcription factors, cell signaling, and DNA damage, confirming that they are a disease continuum. Differences in the frequency of mutated genes in MDS and secondary AML indicate that the order of mutation acquisition is not random during progression. In almost every case, disease progression is associated with clonal evolution, typically defined by the expansion or emergence of a subclone with a unique set of mutations. Monitoring tumor burden and clonal evolution using sequencing provides advantages over using the blast count, which underestimates tumor burden, and could allow for early detection of disease progression prior to clinical deterioration. In this review, we outline advances in the study of MDS to secondary AML progression, with a focus on the genetics of progression, and discuss the advantages of incorporating molecular genetic data in the diagnosis, classification, and monitoring of MDS to secondary AML progression. Because sequencing is becoming routine in the clinic, ongoing research is needed to define the optimal assay to use in different clinical situations and how the data can be used to improve outcomes for patients with MDS and secondary AML.

Hematopoietic Cell Transplantation in the Treatment of Newly Diagnosed Adult Acute Myeloid Leukemia: An Evidence-Based Review from the American Society of Transplantation and Cellular Therapy

The role of hematopoietic cell transplantation (HCT) in the management of newly diagnosed adult acute myeloid leukemia (AML) is reviewed and critically evaluated in this evidence-based review. An AML expert panel, consisting of both transplant and nontransplant experts, was invited to develop clinically relevant frequently asked questions covering disease- and HCT-related topics. A systematic literature review was conducted to generate core recommendations that were graded based on the quality and strength of underlying evidence based on the standardized criteria established by the American Society of Transplantation and Cellular Therapy Steering Committee for evidence-based reviews. Allogeneic HCT offers a survival benefit in patients with intermediate- and high-risk AML and is currently a part of standard clinical care. We recommend the preferential use of myeloablative conditioning in eligible patients. A haploidentical related donor marrow graft is preferred over a cord blood unit in the absence of a fully HLA-matched donor. The evolving role of allogeneic HCT in the context of measurable residual disease monitoring and recent therapeutic advances in AML with regards to maintenance therapy after HCT are also discussed.

CPX-351 daunorubicin-cytarabine liposome: a novel formulation to treat patients with newly diagnosed secondary acute myeloid leukemia

Over the last few years, we assisted to an increasing knowledge about acute myeloid leukemia (AML) pathobiology. However, outcomes remain unsatisfactory particularly for adult patients over 60 years old. Not surprisingly several cases of therapy-related AML (tAML) and secondary AML, both characterized by poorer prognosis, are more common in older population. For several decades initial therapy for AML remained unchanged and typically treatment consisted of an anthracycline combined with continuous infusion of cytarabine for 7 days, the so-called "7+3" standard regimen. The efforts made by the researchers to improve this standard schedule, have led to only modest improvement in the response rate (RR) but no change in overall survival (OS), until the recent evolution seen with new target specific mutation therapies. In 2017, a new liposomal-encapsulated formulation with daunorubicin and cytarabine (CPX-351) was approved by the US Food and Drug Administration for the treatment of newly diagnosed tAML or AML with myelodysplasia-related changes (AML-MRCs). Based on the findings that ratiometric delivery may be more effective than administration of either drug at their maximum tolerated dose (MTD), CPX-351 was designed to deliver a fixed 5:1 molar ratio of the two molecules historically used in the standard "7+3" regimen, cytarabine and daunorubicin respectively. CPX-351 did show improvements of overall survival compared to traditional "7+3" in newly diagnosed secondary and therapy-related AML in adult patients. However, questions remain regarding how to select across AML patient subgroups to maximize the clinical benefit. Possible future directions include evaluating CPX-351 dose intensification, combining this liposomal formulation with targeted therapies and not least important a better understanding about the mechanism of improved responses in tAML and AML-MRC, two entities recognized to be less chemo-sensitive than other hematologic malignancies. In summary, CPX-351 offers finally something new in the landscape of AML therapy. Herein we will review the rationale behind this new drug product development, the main pharmacological characteristics, and discuss the results of clinical trials that led to its FDA approval at first and by EMA in 2018.

Genetic and Genomic Landscape of Secondary and Therapy-Related Acute Myeloid Leukemia

A subset of acute myeloid leukemia (AML) arises either from an antecedent myeloid malignancy (secondary AML, sAML) or as a complication of DNA-damaging therapy for other cancers (therapy-related myeloid neoplasm, t-MN). These secondary leukemias have unique biological and clinical features that distinguish them from de novo AML. Over the last decade, molecular techniques have unraveled the complex subclonal architecture of sAML and t-MN. In this review, we compare and contrast biological and clinical features of de novo AML with sAML and t-MN. We discuss the role of genetic mutations, including those involved in RNA splicing, epigenetic modification, tumor suppression, transcription regulation, and cell signaling, in the pathogenesis of secondary leukemia. We also discuss clonal hematopoiesis in otherwise healthy individuals, as well as in the context of another malignancy, and how it challenges the conventional notion of sAML/t-MN. We conclude by summarizing the current and emerging treatment strategies, including allogenic transplant, in these complex scenarios.

Comparison of therapy-related and de novo core binding factor acute myeloid leukemia: A bone marrow pathology group study

This multi-institutional study retrospectively evaluated clinicopathologic and genetic characteristics in 351 patients with core-binding-factor acute myeloid leukemia (CBF-AML), comprising 69 therapy-related (t-CBF-AML) and 282 de novo cases. The T-CBF-AML patients were older, had lower WBC counts, and slightly higher hemoglobin than patients with de novo disease. Secondary cytogenetic abnormalities were more frequent in patients with de novo disease than t-CBF-AML (57.1% vs 41.1%, P = .026). Patients with secondary cytogenetic abnormalities had longer overall survival (OS) than those without abnormalities (median 190 vs 87 months, P = .021); trisomy 8, trisomy 22, and loss of the X or Y chromosome were associated with longer OS. In the 165 cases performed of targeted gene sequencing, pathogenic mutations were detected in 75.7% of cases, and were more frequent in de novo than in therapy-related disease (P = .013). Mutations were found in N/KRAS (37.0%), FLT3 (27.8%), KIT (17.2%), TET2 (4.9%), and ASXL1 (3.9%). The TET2 mutations were associated with shorter OS (P = .012) while N/KRAS mutation was associated with longer OS in t(8;21) AML patients (P = .001). The KIT mutation did not show prognostic significance in this cohort. Although they received similar therapy, t-CBF-AML patients had shorter OS than de novo patients (median 69 vs 190 months, P = .038). In multivariate analysis of all patients, older age and absence of any secondary cytogenetic abnormalities were significant predictors of shorter OS. Among the t-CBF-AML subset, age and hemoglobin were significant on multivariate analysis. This study demonstrated that although de novo and t-CBF-AML patients share many features, t-CBF-AML patients have worse clinical outcome than de novo patients.

Inferior outcome of allogeneic stem cell transplantation for secondary acute myeloid leukemia in first complete remission as compared to de novo acute myeloid leukemia

Following chemotherapy, secondary acute myeloid leukemia (sAML), occurring after antecedent hematologic diseases, previous chemotherapy or radiation, has an inferior prognosis compared with de novo AML. To define the outcome of sAML in the context of allogeneic stem cell transplantation (alloSCT), a retrospective, registry-based comparison was performed, including 11,439 patients with de novo and 1325 with sAML. Among transplants in first complete remission (CR1) (n = 8,600), the 3-year cumulative incidence of relapse (RI) and non-relapse mortality (NRM) was 28.5% and 16.4% for de novo, and 35% and 23.4% for sAML. Three-year overall survival (OS), leukemia-free survival (LFS) and Graft-versus-Host Disease/relapse-free survival (GRFS) was 60.8%, 55.1%, and 38.6% for de novo, and 46.7%, 41.6%, and 28.4% for sAML, respectively. In multivariate analysis, sAML was associated with a lower OS (HR = 1.33 [95% CI = 1.21–1.48]; p < 10⁻⁵), LFS (HR = 1.32 [95% CI = 1.19–1.45]; p < 10⁻⁵) and GRFS (HR = 1.2 [95% CI = 1.1–1.31]; p < 10⁻⁴) and higher NRM (HR = 1.37 [95% CI = 1.17–1.59]; p < 10⁻⁴) and RI (HR = 1.27 [95% CI = 1.12–1.44]; p < 10⁻³). Results of the Cox model were confirmed in a matched-pair analysis. In contrast, results did not differ between de novo and sAML after alloSCT in induction failure or relapse. Hence, this analysis identified sAML as an independent risk factor for outcome after alloSCT in CR1.

Treatment Strategies for Therapy-related Acute Myeloid Leukemia

Prospective evidence for management of therapy-related acute myeloid leukemia (t-AML) is limited, with evidence extrapolated from major AML trials. Optimal treatment is challenging and needs consideration of patient-specific, disease-specific, and therapy-specific factors. Clinical trials are recommended, especially for unfit patients or those with unfavorable cytogenetics or mutations. CPX-351 as an upfront intensive chemotherapy is preferred for fit patients; venetoclax with decitabine or azacitidine is an option for patients unfit for intensive chemotherapy. Hematopoietic cell transplant, the only curative option, should be offered to eligible patients with intermediate or unfavorable t-AML or patients with good-risk AML with minimal residual disease. Ongoing clinical trials focusing on treatment of t-AML, including targeted agents and immunotherapy, bode well for the future.

Clinicopathological aspects of therapy-related acute myeloid leukemia and myelodysplastic syndrome

Therapy-related myeloid neoplasm (t-MN) is a rare but devastating consequence of chemotherapy and/or radiotherapy used for the treatment of solid cancers and various hematologic malignancies. Our current understanding of the etiology is that hematopoietic clones that are contemporaneous with the primary cancer and resistant to the cytotoxic exposure have the potential to undergo selective expansion and transformation to t-MN. Consequently, a large proportion of cases are associated with adverse risk factors, resulting in limited effective treatment options. Despite the emergence of some therapies with promising activity in t-MN, most effects are short-lived and allogeneic stem cell transplantation remains the only curative option for eligible patients. This review summarizes the current literature on t-AML and t-MDS, with the aim of providing practical recommendations on the clinical evaluation and management of these conditions.

The leukemia strikes back: a review of pathogenesis and treatment of secondary AML

Secondary AML is associated with a disproportionately poor prognosis, consistently shown to exhibit inferior response rates, event-free survival, and overall survival in comparison with de novo AML. Secondary AML may arise from the evolution of an antecedent hematologic disorder, or it may arise as a complication of prior cytotoxic chemotherapy or radiation therapy in the case of therapy-related AML. Because of the high frequency of poor-risk cytogenetics and high-risk molecular features, such as alterations in TP53, leukemic clones are often inherently chemoresistant. Standard of care induction had long remained conventional 7 + 3 until its reformulation as CPX-351, recently FDA approved specifically for secondary AML. However, recent data also suggests relatively favorable outcomes with regimens based on high-dose cytarabine or hypomethylating agents. With several investigational agents being studied, the therapeutic landscape becomes even more complex, and the treatment approach involves patient-specific, disease-specific, and therapy-specific considerations.

Better treatment outcomes in patients with actively treated therapy-related myeloid neoplasms harboring a normal karyotype

We analyzed treatment outcomes and prognostic factors in adult patients with therapy-related myeloid neoplasms (t-MNs) to select patients who would be benefited by active anticancer treatment. After excluding 18 patients who received palliative care only and 13 patients with acute promyelocytic leukemia, 72 t-MN patients (45 with acute myeloid leukemia and 27 with myelodysplastic syndrome) were retrospectively evaluated. Among them, 10 (13.9%), 32 (44.4%), and 30 patients (41.7%) had favorable, intermediate- and adverse-risk cytogenetics, respectively. Among patients with intermediate-risk cytogenetics, patients with a normal karyotype (NK; N = 20) showed superior allogeneic stem cell transplantation-censored overall survival (AC-OS) and OS compared to those with non-NK-intermediate-risk cytogenetics (P < 0.001). In the multivariate analysis, male sex, age ≥ 70 years, and unfavorable cytogenetics (non-NK-intermediate plus adverse risk cytogenetics) were associated with inferior AC-OS. Those results suggest that a more-refined subdivision of risk stratification would be necessary in patients with intermediate-risk cytogenetics.

Daunorubicin and Cytarabine Liposome in Newly Diagnosed Therapy-Related Acute Myeloid Leukemia (AML) or AML With Myelodysplasia-Related Changes

OBJECTIVE

To evaluate the efficacy and safety of daunorubicin and cytarabine liposome in older adults with newly diagnosed therapy-related acute myeloid leukemia (t-AML) or AML with myelodysplasia-related changes (AML-MRC).

DATA SOURCE

A literature search of PubMed and MEDLINE (January 2017 to January 2018) was performed using the terms CPX-351, Vyxeos, daunorubicin and cytarabine liposome, and acute myeloid leukemia.

STUDY SELECTION/DATA EXTRACTION

Phase I, II, and III clinical trials evaluating the efficacy and safety of daunorubicin and cytarabine liposome were reviewed with a specific focus on its use in older patients with newly diagnosed AML. All peer-reviewed articles with clinically relevant information were evaluated for inclusion.

DATA SYNTHESIS

The phase II trial demonstrated that daunorubicin and cytarabine liposome improved response rates (RR), but there was no difference in event-free survival and overall survival in the overall patient population. However, clinical benefit was most pronounced in secondary AML with an increased RR and survival. The phase III trial illustrated that daunorubicin and cytarabine liposome improved survival and RR with tolerable toxicity compared with standard 7 plus 3 (daunorubicin and cytarabine) in patients 60 to 75 years of age with t-AML or AML-MRC. More patients proceeded to a stem cell transplant, and 30-day and 60-day mortality was lower with daunorubicin and cytarabine liposome. Grade 3 to 5 toxicities were similar between the 2 groups, except daunorubicin and cytarabine liposome had prolonged cytopenia and a higher risk of hemorrhage.

CONCLUSIONS

Daunorubicin and cytarabine liposome improves RR and survival, with tolerable toxicity in older patients with t-AML or AML-MRC.

Therapy-related myeloid neoplasms

PURPOSE OF REVIEW

Advances in the genetic characterization of patients with therapy-related myeloid neoplasms (t-MNs) have changed our understanding of the pathogenesis of these diseases. In addition, extensive sequencing studies have identified recurrent mutations with diagnostic and prognostic impact. Thus, the revised version of the WHO classification combines therapy-related myelodysplastic syndromes (t-MDS) and therapy-related acute myeloid leukemia (t-AML) in the one entity of t-MNs because of their similar pathogenesis, rapid progression from t-MDS to t-AML, and their equally poor prognosis.

RECENT FINDINGS

Fifteen percent of t-AML patients present with favorable risk fusion genes, whereas 50% have adverse cytogenetics. The most frequent molecular aberration in t-AML and t-MDS affects TP53 (33%). Selection of a pre-existing treatment-resistant hematopoietic stem cell clone with TP53 mutation has been shown as an important mechanism in the development of t-MNs and explains the high frequency of TP53 mutations in these patients. Following previous cytotoxic therapy, patients develop specific vulnerabilities, which become especially evident as high nonrelapse mortality of t-MN patients after allogeneic hematopoietic cell transplantation.

SUMMARY

Patients are treated according to their genetic risk profile. Assessment of minimal residual disease helps to guide allogeneic transplantation for patients with favorable risk and genetic markers.

Therapy-related myeloid neoplasms: when genetics and environment collide

Therapy-related myeloid neoplasms (t-MN) arise as a late effect of chemotherapy and/or radiation administered for a primary condition, typically a malignant disease, solid organ transplant or autoimmune disease. Survival is measured in months, not years, making t-MN one of the most aggressive and lethal cancers. In this Review, we discuss recent developments that reframe our understanding of the genetic and environmental aetiology of t-MN. Emerging data are illuminating who is at highest risk of developing t-MN, why t-MN are chemoresistant and how we may use this information to treat and ultimately prevent this lethal disease.

Therapy-related myeloid neoplasms: does knowing the origin help to guide treatment?

Therapy-related myeloid neoplasms (t-MN) combine t-MDS and therapy related acute myeloid leukemia (t-AML) patients in one entity because of their similar pathogenesis, rapid progression from t-MDS to t-AML, and their equally poor prognosis. Treatment with epipodophyllotoxins like etoposide has been associated with a short interval between treatment and development of t-AML, with fusion oncogenes like KMT2A/MLL-MLLT3 and a better prognosis. In contrast, treatment with alkylating agents has been associated with a longer latency, an initial MDS phase, adverse cytogenetics, and a poor prognosis. The pathogenesis of t-MN can be explained by direct induction of an oncogene through chromosomal translocations, induction of genetic instability, or selection of a preexisting treatment-resistant hematopoietic stem cell clone. Recent evidence has highlighted the importance of the last mechanism and explains the high frequency of TP53 mutations in patients with t-MN. After previous cytotoxic therapy, patients present with specific vulnerabilities, especially evident from the high nonrelapse mortality in patients with t-MN after allogeneic hematopoietic cell transplantation. Here, the prognostic impact of currently known risk factors and the therapeutic options in different patient subgroups will be discussed.

Therapy-related myeloid neoplasms: does knowing the origin help to guide treatment?

Therapy-related myeloid neoplasms (t-MN) combine t-MDS and therapy related acute myeloid leukemia (t-AML) patients in one entity because of their similar pathogenesis, rapid progression from t-MDS to t-AML, and their equally poor prognosis. Treatment with epipodophyllotoxins like etoposide has been associated with a short interval between treatment and development of t-AML, with fusion oncogenes like KMT2A/MLL-MLLT3 and a better prognosis. In contrast, treatment with alkylating agents has been associated with a longer latency, an initial MDS phase, adverse cytogenetics, and a poor prognosis. The pathogenesis of t-MN can be explained by direct induction of an oncogene through chromosomal translocations, induction of genetic instability, or selection of a preexisting treatment-resistant hematopoietic stem cell clone. Recent evidence has highlighted the importance of the last mechanism and explains the high frequency of TP53 mutations in patients with t-MN. After previous cytotoxic therapy, patients present with specific vulnerabilities, especially evident from the high nonrelapse mortality in patients with t-MN after allogeneic hematopoietic cell transplantation. Here, the prognostic impact of currently known risk factors and the therapeutic options in different patient subgroups will be discussed.

Chronic myeloid leukemia among patients with a history of prior malignancies: A tale of dual survivorship

BACKGROUND

Some patients with chronic myeloid leukemia (CML) have a history of previous malignancies. To the authors' knowledge, outcomes for CML diagnosed in these patients have not been well described. The current study was conducted to determine the outcome of patients with CML and a history of prior malignancies.

METHODS

The current study included patients who were enrolled in clinical trials of tyrosine kinase inhibitors as initial therapy for CML in chronic phase from July 2000 to January 2014.

RESULTS

Of the 630 patients with CML who were treated with frontline tyrosine kinase inhibitors, 626 had a known prior malignancy status. Of these, 45 patients (7%) had a prior malignancy other than nonmelanoma skin cancer whereas 17 patients (3%) had a history of nonmelanoma skin cancers alone. Characteristics of CML were similar between the patients with no prior malignancy, those with a prior malignancy, and those with nonmelanoma skin cancer. Patients with a prior malignancy were found to have an older median age compared with the other 2 groups. The most common prior malignancies were nonmelanoma skin cancer in 20 patients, breast cancer in 11 patients, melanoma in 7 patients, prostate cancer in 6 patients, and colorectal cancer in 5 patients. With regard to CML, the event-free survival, transformation-free survival, and failure-free survival rates were found to be similar between the groups. There was a statistically significantly decreased survival in the group with a prior malignancy versus the group with no prior malignancy versus the group with nonmelanoma skin cancer. In a multivariate analysis, advanced age and an elevated creatinine level were found to be associated with worse survival after a diagnosis of CML.

CONCLUSIONS

Patients with CML with a history of prior malignancies appear to have the same excellent outcome as patients with no prior malignancies. In the few instances in which concomitant therapy for other malignancies was required during therapy with tyrosine kinase inhibitors, this was able to be accomplished without significant toxicity. Cancer 2017;123:609-616. © 2016 American Cancer Society.

Outcome of Patients With Therapy-Related Acute Myeloid Leukemia With or Without a History of Myelodysplasia

PURPOSE

To learn whether an antecedent hematologic disorder (AHD) is associated with additional risk in patients with therapy-related acute myeloid leukemia (t-AML).

PATIENTS AND METHODS

We reviewed data of 301 patients with newly diagnosed t-AML who sought care from January 2000 to January 2014 (183 t-AML without AHD, 118 t-AML with AHD). Overall, median follow-up was 44 months.

RESULTS

The primary malignancy was non-Hodgkin lymphoma in 92 (31%), breast cancer in 80 (27%), and prostate cancer in 49 (16%). Median relapse-free survival (RFS) in t-AML without or with AHD was 10 months and 29 months, respectively (P = .032); median overall survival (OS) was 8 months and 8 months, respectively (P = .53). Multivariate analysis for OS identified older age, poor performance status, thrombocytopenia, nonfavorable cytogenetics, and lack of response as adverse factors.

CONCLUSION

The favorable-risk cohort had better RFS and OS compared to the outcomes of patients in the intermediate- and adverse-risk cohorts; the RFS and OS did not differ between intermediate- and adverse-risk cohorts. The presence of AHD did not affect OS.

Therapy-related myeloid neoplasms - what have we learned so far?

Therapy-related myeloid neoplasms are neoplastic processes arising as a result of chemotherapy, radiation therapy, or a combination of these modalities given for a primary condition. The disease biology varies based on the etiology and treatment modalities patients receive for their primary condition. Topoisomerase II inhibitor therapy results in balanced translocations. Alkylating agents, characteristically, give rise to more complex karyotypes and mutations in p53. Other etiologies include radiation therapy, high-dose chemotherapy with autologous stem cell transplantation and telomere dysfunction. Poor-risk cytogenetic abnormalities are more prevalent than they are in de novo leukemias and the prognosis of these patients is uniformly dismal. Outcome varies according to cytogenetic risk group. Treatment recommendations should be based on performance status and karyotype. An in-depth understanding of risk factors that lead to the development of therapy-related myeloid neoplasms would help developing risk-adapted treatment protocols and monitoring patients after treatment for the primary condition, translating into reduced incidence, early detection and timely treatment.

Secondary Adult Acute Myeloid Leukemia: a Review of Our Evolving Understanding of a Complex Disease Process

OPINION STATEMENT

Secondary AML (s-AML) encompasses AML evolving from myelodysplasia (AML-MDS) and treatment-related AML (t-AML) after exposure to chemotherapy, radiation, or environmental toxins. S-AML has traditionally been considered a devastating disease, affecting a vulnerable population of heavily pretreated, older adults. A limited understanding of disease pathogenesis/heterogeneity and lack of effective treatments have hampered overall improvements in patient outcomes. With the recent understanding that the secondary nature of sAML does not by itself incur a poor prognosis and incorporation of cytogenetics and molecular genetics into patient care and the advancement of treatment, including improved supportive care, novel chemotherapeutics agents, and nonmyeloablative conditioning regimens as part of allogeneic hematopoietic cell transplantation (HCT), modest gains in survival and quality of life are beginning to be seen among patients with s-AML.

Is it time to change conventional consolidation chemotherapy for acute myeloid leukemia in CR1?

PURPOSE OF REVIEW

Choosing the most appropriate postremission therapy (PRT) for a patient with acute myeloid leukemia (AML) in first complete remission remains a challenging task. Factors such as risk for disease relapse, nonrelapse mortality associated with different PRT approaches, donor availability, prospects for salvage should disease relapse, and patient preference all affect PRT choice.

RECENT FINDINGS

New genetic markers refine AML risk stratification and identify patients within the 'classical' risk groups who may benefit from transplant-based or chemotherapy-based PRT. The use of minimal residual disease in first remission to guide PRT choice and the application of novel, targeted therapies have the potential to alter PRT approaches across AML risk groups. The advent of alternative donor sources, use of reduced intensity regimens, and improved supportive care all affect the availability and safety of transplant-based PRT and challenge the relevance of the older legacy 'donor/no-donor' genetically randomized trials.

SUMMARY

Genetic risk assessment, monitoring of minimal residual disease in first remission, use of targeted agents, and the newer transplant strategies all have the potential to 'personalize' PRT choice in the AML patient. The clinical value of these novel interventions awaits validation in prospective, risk-adapted clinical trials.

Complex karyotype, older age, and reduced first-line dose intensity determine poor survival in core binding factor acute myeloid leukemia patients with long-term follow-up

Approximately 40% of patients affected by core binding factor (CBF) acute myeloid leukemia (AML) ultimately die from the disease. Few prognostic markers have been identified. We reviewed 192 patients with CBF AML, treated with curative intent (age, 15-79 years) in 11 Italian institutions. Overall, 10-year overall survival (OS), disease-free survival (DFS), and event-free survival were 63.9%, 54.8%, and 49.9%, respectively; patients with the t(8;21) and inv(16) chromosomal rearrangements exhibited significant differences at diagnosis. Despite similar high complete remission (CR) rate, patients with inv(16) experienced superior DFS and a high chance of achieving a second CR, often leading to prolonged OS also after relapse. We found that a complex karyotype (i.e., ≥4 cytogenetic anomalies) affected survival, even if only in univariate analysis; the KIT D816 mutation predicted worse prognosis, but only in patients with the t(8;21) rearrangement, whereas FLT3 mutations had no prognostic impact. We then observed increasingly better survival with more intense first-line therapy, in some high-risk patients including autologous or allogeneic hematopoietic stem cell transplantation. In multivariate analysis, age, severe thrombocytopenia, elevated lactate dehydrogenase levels, and failure to achieve CR after induction independently predicted longer OS, whereas complex karyotype predicted shorter OS only in univariate analysis. The achievement of minimal residual disease negativity predicted better OS and DFS. Long-term survival was observed also in a minority of elderly patients who received intensive consolidation. All considered, we identified among CBF AML patients a subgroup with poorer prognosis who might benefit from more intense first-line treatment.

Therapy-related leukemia with Inv(16)(p13.1q22) and type D CBFB/MYH11 developing after exposure to irinotecan-containing chemoradiotherapy

A 40-year-old woman developed therapy-related acute myeloid leukemia (t-AML) with inv(16)(p13.1q22) and a rare type D form of core-binding factor β-subunit gene-myosin heavy chain 11 gene (CBFB-MYH11) fusion transcript approximately 2.5 years after receiving chemoradiotherapy for uterine cervical cancer. t-AML with inv(16)(p13.1q22) and rare non-type A CBFB-MYH11 typically develops after exposure to a topoisomerase II inhibitor, with a short period of latency of one to five years. As the patient had no history of exposure to topoisomerase II inhibitors, among her previously used chemotherapeutics, the topoisomerase I inhibitor, irinotecan, was speculated to be the most plausible cause of t-AML in this case. The present case suggests that irinotecan may cause t-AML resembling that associated with topoisomerase II inhibitors.

Prognosis and monitoring of core-binding factor acute myeloid leukemia: current and emerging factors

Core-binding factor acute myeloid leukemia (CBF-AML) - including AML with t(8;21) and AML with inv(16) - accounts for about 15% of adult AML and is associated with a relatively favorable prognosis. Nonetheless, relapse incidence may reach 40% in these patients. In this context, identification of prognostic markers is considered of great interest. Due to similarities between their molecular and prognostic features, t(8;21) and inv(16)-AML are usually grouped and reported together in clinical studies. However, considerable experimental evidences have highlighted that they represent two distinct entities and should be considered separately for further studies. This review summarizes recent laboratory and clinical findings in this particular subset of AML and how they could be used to improve management of patients in routine practice.