Cardiotoxicity of CPX-351 in children and adolescents with relapsed AML: a Children's Oncology Group report

Introduction

Anthracyclines are effective in treating acute myeloid leukemia (AML) but limited by cardiotoxicity. CPX-351, a liposomal daunorubicin and cytarabine, may provide therapeutic benefit with less cardiotoxicity. Acute changes in left ventricular systolic function and cardiac biomarkers were evaluated after a cycle of CPX-351 in children with relapsed AML treated on the phase 1/2 Children's Oncology Group study, AAML1421.

Methods

Subjects received 135 units/m2/dose of CPX-351 on days 1, 3, and 5 as cycle 1. Echocardiograms were performed and centrally quantitated at baseline and at the end of cycle 1 (day 29 +/- 1 week). High sensitivity troponin (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured at baseline and serially through the end of cycle 1 (days 5, 8, 15, 22 and 29). Differences between baseline and post-CPX-351 echo/biomarker measures were analyzed using Wilcoxon signed rank tests. Linear regression was used to model post-CPX-351 left ventricular ejection fraction (LVEF) with cTnT/NT-proBNP at each time point, controlling for baseline LVEF. Cancer therapy related cardiac dysfunction (CTRCD) was defined as a decline in LVEF of ≥10%-<50%.

Results

Twenty-five of 38 heavily anthracycline pre-treated (median 348 mg/m2 daunorubicin equivalents) subjects enrolled on AAML1421 were included in the cardiac analyses. At baseline, centrally quantitated LVEF was <50% in 8 of 25 subjects (32%) with a median LVEF of 53.8% [48.0, 56.9]. Following CPX-351, LVEF declined significantly (ΔLVEF -3.3% [-7.8, 0]) and 6 of 25 subjects (24%) experienced CTRCD. Amongst all subjects, hs-cTnT was modestly increased at end of cycle 1 compared to baseline [baseline hs-cTnT 7.2 (3, 10.6); ΔcTnT 1.80 (0, 6.1), p = 0.03]. NT-proBNP remained stably elevated without significant change. No significant associations were seen between NT-proBNP or cTnT levels and post-CPX-351 LVEF.

Discussion

In this single arm study of anthracycline pre-treated children exposed to CPX-351, baseline abnormalities in cardiovascular function were prevalent. Following CPX-351, LVEF decreased, cTnT increased, and NT-proBNP did not change. Longer follow-up is needed to determine whether these changes result in clinically meaningful long-term decrements in cardiac function. An ongoing randomized trial of CPX-351 compared to standard anthracyclines in anthracycline naïve patients will provide further insight into the cardiac effects of CPX-351 (ClinicalTrials.gov; NCT04293562).

A phase 1/2 study of NS-87/CPX-351 (cytarabine and daunorubicin liposome) in Japanese patients with high-risk acute myeloid leukemia

OBJECTIVES

NS-87/CPX-351 is a dual-drug liposomal encapsulation of cytarabine and daunorubicin. NS-87/CPX-351 exerts antileukemic action by maintaining a synergistic molar ratio of cytarabine to daunorubicin of 5:1 within the liposome while in circulation. Patients with high-risk acute myeloid leukemia (AML), which includes therapy-related AML and AML with myelodysplasia-related changes (AML-MRC), have poorer outcomes than those with other AML.

METHODOLOGY

This open-label phase 1/2 (P1/2) study was conducted in 47 Japanese patients aged 60-75 years with newly diagnosed high-risk AML to evaluate the pharmacokinetics, safety, and efficacy of NS-87/CPX-351.

RESULTS

In the 6 patients enrolled in the P1 portion, no dose-limiting toxicities (DLTs) were reported, and 100 units/m2 during the induction cycle was found to be acceptable. Cytarabine and daunorubicin had a long half-life in the terminal phase (32.8 and 28.7 h, respectively). In the 35 patients enrolled in the P2 portion, composite complete remission (CRc; defined as complete remission [CR] or CR with incomplete hematologic recovery [CRi]) was achieved in 60.0% (90% CI: 44.7-74.0) of the patients. Adverse events due to NS-87/CPX-351 were well tolerated.

OUTCOMES

NS-87/CPX-351 can be considered as a frontline treatment option for Japanese patients with high-risk AML.

CPX-351 Pharmacokinetics and Safety in Adults with Hematologic Malignancies and Renal Function Impairment: Phase 1 Trial

This open-label phase 1 study (clinicaltrials.gov, NCT03555955) assessed CPX-351 pharmacokinetics (PK) and safety in patients with hematologic malignancies with normal or impaired renal function. Patients were enrolled into three cohorts based on their creatinine clearance (CrCl): ≥90 mL/min (Cohort 1, normal renal function, n = 7), 30 to <59 mL/min (Cohort 2, moderate renal impairment, n = 8), or <30 mL/min (Cohort 3, severe renal impairment, n = 6). Patients received intravenous CPX-351 for initial induction; blood and urine samples were collected for PK analysis. The primary objective was to assess the PK parameters for cytarabine, daunorubicin, and their respective metabolites, arabinosyluracil (Ara-U) and daunorubicinol. Renal impairment did not significantly impact the cytarabine, daunorubicin, or daunorubicinol exposure, but it caused a slight increase in the Ara-U exposure. The CPX-351 side effect profile was similar in patients with impaired renal function compared to those with normal renal function. All the patients reported ≥1 treatment-emergent adverse event (TEAE), most commonly febrile neutropenia and nausea (57% each) and hyperglycemia (43%); no patients discontinued treatment due to TEAEs. These data suggest that CPX-351 dose adjustment is not required for patients with hematologic malignancies with moderate or severe renal impairment.

CPX-351 and allogeneic stem cell transplant for a therapy-related acute myeloid leukemia that developed after treatment of acute promyelocytic leukemia: a case report and review of the literature

Therapy-related myeloid neoplasms (t-MNs), which develop after cytotoxic, radiation, or immunosuppressive therapy for an unrelated disease, account for 7%-8% of acute myeloid leukemia (AML). Worse outcomes and consequently shortened survival are associated with t-MNs as compared with de novo AML. Therapy-related MNs are being reported with increasing frequency in successfully treated acute promyelocytic leukemia (APL), in particular, before the introduction of all-trans retinoic acid (ATRA) plus arsenic trioxide (ATO). Considering the high curability of APL, t-MNs represent one of the prognosis-limiting factors in this setting of leukemia. We report our experience with a patient who developed t-AML 15 years after treatment for APL. Treatment included three cycles of chemotherapy with CPX-351 (Vyxeos, Jazz Pharmaceuticals) followed, as in remission, by an allogeneic hematopoietic stem cell transplant. A review of available literature was also included.

Case Report of a DDX41 Germline Mutation in a Family with Multiple Relatives Suffering from Leukemia

INTRODUCTION

Previously, it was assumed that genetic influence played a minor role in acute myeloid leukemia (AML). Increasing evidence of germline mutations has emerged, such as DDX41 germline mutation associated with familial AML.

CASE PRESENTATION

A 64-year-old male patient presented with reduced exercise tolerance and shortness of breath. Following confirmation of AML diagnosis, the patient was enrolled into the AMLSG-30-18 study with a requirement for allogenic stem cell transplantation. The sister was initially selected as a fully HLA-matched donor. However, the family history showed risks for familial AML. Due to the striking family history, further diagnostic steps were initiated to detect a germline mutation.

METHODS

Using NGS in the patients' bone marrow AML sample, a DDX41 mutation with a VAF of 49% was detected, raising the possibility of a germline mutation. DNA from cheek swabs and eyebrows were tested for the presence of the DDX41 mutation in all siblings.

RESULTS

DDX41 germline mutation was detected in 5 out of 6 siblings. The sister was excluded as a related donor and the search for an unrelated donor was initiated.

CONCLUSION

Obtaining family history of cancer patients plays a crucial role in oncology. If a germline mutation is suspected, further family work-up should be initiated.

Rationale and design of the Children's Oncology Group study AAML1831 integrated cardiac substudies in pediatric acute myeloid leukemia therapy

Background

Pediatric acute myeloid leukemia (AML) therapy is associated with substantial short- and long-term treatment-related cardiotoxicity mainly due to high-dose anthracycline exposure. Early left ventricular systolic dysfunction (LVSD) compromises anthracycline delivery and is associated with inferior event-free and overall survival in de novo pediatric AML. Thus, effective cardioprotective strategies and cardiotoxicity risk predictors are critical to optimize cancer therapy delivery and enable early interventions to prevent progressive LVSD. While dexrazoxane-based cardioprotection reduces short-term cardiotoxicity without compromising cancer survival, liposomal anthracycline formulations have the potential to mitigate cardiotoxicity while improving antitumor efficacy. This overview summarizes the rationale and methodology of cardiac substudies within AAML1831, a randomized Children's Oncology Group Phase 3 study of CPX-351, a liposomal formulation of daunorubicin and cytarabine, in comparison with standard daunorubicin/cytarabine with dexrazoxane in the treatment of de novo pediatric AML.

Methods/design

Children (age <22 years) with newly diagnosed AML were enrolled and randomized to CPX-351-containing induction 1 and 2 (Arm A) or standard daunorubicin and dexrazoxane-containing induction (Arm B). Embedded cardiac correlative studies aim to compare the efficacy of this liposomal anthracycline formulation to dexrazoxane for primary prevention of cardiotoxicity by detailed core lab analysis of standardized echocardiograms and serial cardiac biomarkers throughout AML therapy and in follow-up. In addition, AAML1831 will assess the ability of early changes in sensitive echo indices (e.g., global longitudinal strain) and cardiac biomarkers (e.g., troponin and natriuretic peptides) to predict subsequent LVSD. Finally, AAML1831 establishes expert consensus-based strategies in cardiac monitoring and anthracycline dose modification to balance the potentially competing priorities of cardiotoxicity reduction with optimal leukemia therapy.

Discussion

This study will inform diagnostic, prognostic, preventative, and treatment strategies regarding cardiotoxicity during pediatric AML therapy. Together, these measures have the potential to improve leukemia-free and overall survival and long-term cardiovascular health in children with AML. Clinical trial registration: https://clinicaltrials.gov/, identifier NCT04293562.

CPX-351 in FLT3-mutated acute myeloid leukemia

CPX-351, a dual-drug liposomal encapsulation of daunorubicin and cytarabine in a 1:5 molar ratio, is approved for the treatment of newly diagnosed therapy-related acute myeloid leukemia (AML) or AML with myelodysplasia-related changes. In a pivotal phase III trial, CPX-351 significantly improved overall survival compared with standard-of-care 7 + 3 chemotherapy (7 days cytarabine; 3 days daunorubicin) in adults aged 60-75 years with newly diagnosed high-risk or secondary AML (median = 9.56 months vs. 5.95 months; hazard ratio = 0.69; 95% confidence interval = 0.52-0.90; p = 0.003). Approximately 30% of patients with newly diagnosed AML have mutations in the FLT3 gene, which may be associated with poor outcomes. Here, we review the current in vitro, clinical, and real-world evidence on the use of CPX-351 in patients with AML and mutations in FLT3. Additionally, we review preliminary data from clinical trials and patient case reports that suggest the combination of CPX-351 with FLT3 inhibitors may represent another treatment option for patients with FLT3 mutation-positive AML.

A comparative safety review of targeted therapies for acute myeloid leukemia

INTRODUCTION

Acute myeloid leukemia (AML) treatment has primarily focused on 7 + 3 chemotherapy, but in the last decade there has been a significant increase in new therapies, mostly targeted agents, approved for the treatment of AML. We performed a comparative analysis of the unique safety profile of each of these new agents.

AREAS COVERED

We conducted a review of the current literature on public databases (PubMed, ClinicalTrials.gov, and U.S. Food and Drug Administration) regarding new AML drugs that were approved from 2017 to 2023.

EXPERT OPINION

The diagnosis of AML typically carries a poor prognosis but with an increase in the number of drugs that are now available, patients' outcomes are improving. With novel mechanisms of action, the use of these agents introduces different safety profiles, occasionally with adverse events not previously seen with standard chemotherapy or at different frequencies. An understanding of the drugs available and the safety concerns associated with each one is crucial to selecting the best available option for each patient, and early recognition and appropriate management of drug-related adverse effects.

Progress toward Better Treatment of Therapy-Related AML

Therapy-related acute myeloid leukemia (t-AML) comprises 10-20% of all newly diagnosed cases of AML and is related to previous use of chemotherapy or ionizing radiotherapy for an unrelated malignant non-myeloid disorder or autoimmune disease. Classic examples include alkylating agents and topoisomerase II inhibitors, whereas newer targeted therapies such as poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitors have emerged as causative agents. Typically, t-AML is characterized by adverse karyotypic abnormalities and molecular lesions that confer a poor prognosis. Nevertheless, there are also cases of t-AML without poor-risk features. The management of these patients remains controversial. We describe the causes and pathophysiology of t-AML, putting emphasis on its mutational heterogeneity, and present recent advances in its treatment including CPX-351, hypomethylating agent plus venetoclax combination, and novel, molecularly targeted agents that promise to improve the cure rates. Evidence supporting personalized medicine for patients with t-AML is presented, as well as the authors' clinical recommendations.

Efficacy and safety of CPX-351 versus 7 + 3 chemotherapy by European LeukemiaNet 2017 risk subgroups in older adults with newly diagnosed, high-risk/secondary AML: post hoc analysis of a randomized, phase 3 trial

CPX-351 (Europe: Vyxeos^® liposomal; United States: Vyxeos^®) is a dual-drug liposomal encapsulation of daunorubicin and cytarabine in a synergistic 1:5 molar ratio. In a phase 3 study in older adults with newly diagnosed, high-risk/secondary AML, CPX-351 improved the remission frequency, overall survival, and post-transplant survival versus 7 + 3. This post hoc analysis evaluated the final 5-year follow-up outcomes according to the European LeukemiaNet 2017 risk classification. CPX-351-treated patients had a higher remission frequency (adverse risk: 41% vs 26%; intermediate risk: 58% vs 39%) and longer median overall survival (adverse risk: 7.59 vs 5.52 months; intermediate risk: 11.86 vs 7.75 months) and post-transplant survival (adverse risk: 43.14 vs 7.08 months; intermediate risk: not reached vs 13.57 months) versus 7 + 3, with outcomes generally poorer among patients with adverse-risk AML. The safety profile of CPX-351 among patients with adverse-risk or intermediate-risk AML was consistent with that of the overall study population. Early mortality was lower, and hospitalization length of stay per patient-year was shorter with CPX-351 versus 7 + 3 within the adverse-risk and intermediate-risk subgroups. The favorable outcomes observed with CPX-351 in this post hoc analysis are consistent with results for the overall study population and further support the use of CPX-351 in these patients.ClinicalTrials.gov Identifier: NCT01696084.

CPX-351 Yields Similar Response and Survival Outcome in Younger and Older Patients With Secondary Acute Myeloid Leukemia

BACKGROUND

CPX-351 was approved by the FDA in 2017 as frontline induction chemotherapy for patients aged ≥18 years with newly diagnosed acute myeloid leukemia (AML) which includes myelodysplasia-related changes (AML-MRC) and therapy-related acute myeloid leukemia (t-AML). The efficacy of CPX-351 among younger patients (aged <60 years) is currently unclear, as the large, randomized phase 3 study that led to approval of CPX-351 only included patients between the ages of 60 and 75 years.

METHODS

We performed a retrospective study of clinical and molecular data from adult patients with newly diagnosed AML-MRC or t-AML treated with CPX-351. Patients were divided into 2 cohorts: aged <60 years (cohort A) and aged ≥60 years (cohort B). We compared overall response rate (ORR) and median overall survival (mOS) between the cohorts.

RESULTS

Of 169 evaluable patients, 21.3% were in cohort A and 78.7% were in cohort B. ORR of the entire cohort was 53.3%; ORR of cohort A was 47.2% compared with 54.9% for cohort B (P = .46). Overall, 54.4% of responding patients proceeded to allogenic stem cell transplant (allo-SCT), including 52.9% of patients in cohort A and 54.8% in cohort B (P = 1.00). At a median follow-up of 24 months, mOS of the entire cohort was 16 months and was similar between cohorts A and B (18 vs. 15 months, respectively; P = .29).

CONCLUSION

CPX-351 resulted in similar response rates and survival outcomes among both younger and older adult patients with newly diagnosed AML-MRC or t-AML.

CPX-351: An Old Scheme with a New Formulation in the Treatment of High-Risk AML

Simple Summary

Secondary AML (s-AML) including therapy-related acute myeloid leukemia (t-AML) and acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) represent approximately one quarter of all AML cases. These AML subcategories are predominantly associated with advanced age and present a specific biologic profile including adverse genetics and a multidrug resistance phenotype, which often determine dramatically poor outcomes after conventional chemotherapy. In 2017, the FDA approved CPX-351, a liposomal formulation of cytarabine and daunorubicin at a fixed 5:1 molar ratio, for the treatment of adults with newly diagnosed t-AML and MRC-AML. Since the approval, many trials have been conducted or are still ongoing in order to assess the role of CPX-351 as frontline treatment in different AML subcategories, as a potential bridge to transplant or in combination with target therapies. In this review, we will discuss the current role of CPX-351 in treating these high-risk AML, focusing on how its use may potentially change the treatment paradigms of AML.

Abstract

Therapy-related acute myeloid leukemia (t-AML) and acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) represent aggressive diseases characterized by a dismal prognosis if compared with de novo acute myeloid leukemia, especially in older patients. In these AML subsets, standard chemotherapy regimens produce poor response rates and unsatisfactory outcomes. Historically, conventional approaches consisted of an anthracycline combined with continuous infusion of cytarabine for 7 days, the “3+7” regimen. Several attempts have been conducted to ameliorate this combination regimen but inconsistent improvements in response rates and no significant changes in overall survival have been observed, until the recent introduction of targeted molecules. A liposomal formulation of traditional chemotherapy agents cytarabine and daunorubicin, termed CPX-351, enhances pharmacodynamics and synergistic effects through the maintenance of the optimal 5:1 molar ratio, which extends the treatment’s half-life and increases the bone marrow tropism of the drug. The use of CPX-351 in newly diagnosed AML-MRC and t-AML patients aged 60–75 years has demonstrated superior remission rates compared to conventional chemotherapy and improvements in event-free and overall survival. Recently, published data from a 5-year follow-up highlighted evidence that CPX-351 has the ability to produce and contribute to long-term remission and survival in older patients with newly diagnosed high-risk/secondary AML. Future perspectives include evaluation of dose intensification with CPX-351 in high-risk settings, combining this agent with targeted therapies, and better understanding the mechanism of improved responses in t-AML and AML-MRC. In this review, we will examine the role of CPX-351 inside the new AML therapeutic scenario and how its employment could potentially modify the treatment algorithm of high-risk and elderly patients with AML

Older Patients with Acute Myeloid Leukemia Deserve Individualized Treatment

PURPOSE OF REVIEW

Treatment of elderly patients with acute myeloid leukemia is a known challenge for hematologists due to patient diversity, heterogeneous disease biology, and a rapidly evolving treatment landscape. Here, we highlight the importance of determining fitness, review the latest therapeutic developments, and discuss clinical scenarios to provide guidance on individualized treatment for older AML patients.

RECENT FINDINGS

Several factors, like age, performance status, and comorbidities, play a role in fitness and are associated with outcome. Comorbidity scoring systems and geriatric assessments are tools to help physicians select the most appropriate treatment for each patient. The addition of venetoclax, targeted therapy with IDH1/2 and FLT3 inhibitors, and enhanced formulas of existing drugs like CPX-351 and oral azacitidine have improved responses and outcomes. New drugs and combination therapies have increased the therapeutic options for elderly AML patients but determination of fitness and disease biology is essential to select patient-tailored treatments.

Pharmacoeconomic considerations for acute myeloid leukemia pharmacotherapy

INTRODUCTION

Acute myeloid leukemia (AML) is a rare blood cancer with a poor prognosis. Recently, targeted drugs have improved survival both in the elderly and in fit patients. However, as monthly costs of targeted agents are high, regulatory bodies often impose restrictions on their use.

AREAS COVERED

The authors review the value-for-cost of targeted drugs such as gemtuzumab ozogamycin, CPX-351, midostaurin, gilteritinib, glasdegib, venetoclax, oral azacytidine and enasidenib used to treat adult AML. EMBASE and TRIP databases, together with authority websites were searched for technology assessments. Add-on drugs, namely midostaurin and gemtuzumab ozogamycin, have been reported to have the best pharmacoeconomic profile for newly diagnosed fit patients with FLT3 mutation or favorable/intermediate cytogenetics, since allogeneic transplant rates were stable or reduced. Most of the other drugs, on the other hand, did not achieve highly favorable cost-for-benefit, due to a poor absolute survival gain and/or increased transplant rates.

EXPERT OPINION

The cost of most targeted therapies for AML in unfit patients seems unfair in comparison to the absolute survival advantage provided in fit patients. Point of cure and transplant outcomes should be standardized to allow comparability among the models.

A Relapsing Meningeal Acute Myeloid Leukaemia FLT3-ITD+ Responding to Gilteritinib

A patient with a therapy-related acute myeloid leukaemia (AML), NPM1mut, and FLT3-ITD+ was treated with induction and consolidation with CPX-351, obtaining a complete response (CR) but minimal residual disease persisted positive. Later, she complained progressive burning leg pain, weakening of the right hand and leg muscles, associated with absence of osteotendinous leg reflexes. Examination of cerebrospinal fluid (CSF) showed a meningeal relapse of AML. Moreover, a magnetic resonance imaging (MRI) showed 2 right meningeal implants of myeloid sarcoma and bone marrow revealed haematologic relapse of disease. She was treated with medicated lumbar punctures (LPs) followed by an FLA-Ida scheme, and she achieved a 2nd CR. Unfortunately, the patient developed hyperleucocytosis and reappearance of meningeal myeloid sarcoma at MRI. For this reason, a monotherapy with gilteritinib (an FLT3 inhibitor) was started: after 3 months of therapy, central nervous system (CNS)-disease shrunken and then faded, while AML in the bone marrow achieved only a partial response. This is the 1st report of a positive biological effect of gilteritinib on CNS (meningeal) myeloid sarcoma. There are no studies of gilteritinib concentration into CSF and penetration of gilteritinib into the blood-brain barrier should be further studied, given the paucity of drugs active on CNS relapse of AML. In patients receiving CPX-351 only, diagnostic LP should be considered after induction.

Management and Outcomes of Blast Transformed Chronic Myelomonocytic Leukemia

PURPOSE OF REVIEW

Despite recent advances in the treatment of de novo acute myeloid leukemia (AML), AML arising from antecedent chronic myelomonocytic leukemia (CMML) continues to have dismal outcomes. While the unique biological drivers of CMML and subsequent leukemic transformation (LT) have been revealed with advances in molecular characterization, this has not yet translated to the bedside. Here, we review these biologic drivers, outcomes with current therapies, and rationale avenues of future investigation specifically in blast phase CMML (CMML-BP).

RECENT FINDINGS

CMML-BP outcomes are studied as an aggregate with more common categories of AML with myelodysplasia-related changes (AML-MRCs) or the even broader category of secondary AML (sAML), which illustrates the crux of the problem. While a modest survival advantage with allogeneic hematopoietic stem cell transplant exists, the difficulty is bridging patients to transplant and managing patients that require an allograft-sparing approach. Limited data suggest that short-lived remissions can be obtained employing CPX-351 or venetoclax-based lower intensity combination therapy. Promising future strategies include repurposing cladribine, exploiting the supportive role of dendritic cell subsets with anti-CD123 therapies, MCL-1 inhibition, dual MEK/PLK1 inhibition, FLT3 inhibition in RAS-mutated and CBL-mutated subsets, and immune therapies targeting novel immune checkpoint molecules such as the leukocyte immunoglobulin-like receptor B4 (LILRB4), an immune-modulatory transmembrane protein restrictively expressed on monocytic cells. The successful management of an entity as unique as CMML-BP will require a cooperative, concerted effort to design and conduct clinical trials dedicated to this rare form of sAML.

3+7 Combined Chemotherapy for Acute Myeloid Leukemia: Is It Time to Say Goodbye?

PURPOSE OF REVIEW

With the recent approval of multiple new drugs for the treatment of acute myeloid leukemia (AML), the relevance of conventional treatment approaches, such as daunorubicin and cytarabine ("3+7") induction chemotherapy, has been challenged. We review the AML risk stratification, the efficacy of the newly approved drugs, and the role of "3+7".

RECENT FINDINGS

Treatment of AML is becoming more niched with specific subtypes more appropriately treated with gemtuzumab, midostaurin, and CPX-351. Although lower intensity therapies can yield high response rates, they are less efficient at preventing relapses. The only curative potential for poor-risk AML is still an allogeneic stem cell transplant. The number of AML subtypes where 3+7 alone is an appropriate therapeutic option is shrinking. However, it remains the backbone for combination therapy with newer agents in patients suitable for intensive chemotherapy.

Impact of induction chemotherapy with intermediate-dosed cytarabine and subsequent allogeneic stem cell transplantation on the outcome of high-risk acute myeloid leukemia

Background

Acute myeloid leukemia (AML) with antecedent hematological disease (s-AML) and treatment-related AML (t-AML) predicts poor prognosis. Intensive treatment protocols of those high-risk patients should consider allogeneic stem cell transplantation (allo-HSCT) in first complete remission (CR). Despite allo-HSCT, relapse rate remains high. Induction chemotherapy with liposomal cytarabine and daunorubicin (CPX-351) has been approved for patients with AML with myeloid-related changes (AML-MRC) or t-AML based on improved survival and remission rates compared to standard 7 + 3 induction.

Patients and methods

110 patients with newly diagnosed s-AML or t-AML at a university hospital were analyzed retrospectively. Median age was 62 years (24–77 years). A total of 65 patients with s-AML after MDS (59%) and 23 patients (20.9%) with t-AML were included. Induction chemotherapy consisted of intermediate-dosed cytarabine (ID-AraC) in combination with idarubicin (patients up to 60 years) or mitoxantrone (patients over 60 years). In patients subsequently undergoing allo-HSCT, reduced conditioning regimens (RIC) were applied prior to transplantation in 47 of 62 patients (76%).

Results

Induction chemotherapy with ID-AraC resulted in an overall response rate of 83% including complete remission (CR/CRi) in 69 patients (63%) with a low rate of early death (2.7%). Most relevant non-hematologic toxicity consisted of infectious complications including sepsis with need of intensive care treatment in five patients (4.5%) and proven or probable invasive fungal disease in eight patients (7.2%). Relapse-free survival (RFS), event-free survival (EFS) and overall survival (OS) of the whole cohort were 19 months (0–167), 10 months (0–234) and 15 months (0–234), respectively (p < 0.0001). A significant improvement of OS was observed in patients who underwent allo-HSCT compared to those without subsequent allo-HSCT: 9 vs. 46 months, p < 0.0001. Rate of transplantation-related mortality (TRM) in the early phase post allo-HSCT was low (0.9% at day 30 and 1.8% at day 90, respectively). RIC conditioning results in OS rate of 60% after 60 months post allo-HSCT (median OS not reached).

Conclusion

S-AML and t-AML patients receiving induction chemotherapy with intermediate-dosed cytarabine showed satisfactory response rate and consolidation therapy with allo-HSCT after full or reduced-intensity conditioning further improved survival in these patients with similar outcome as reported for CPX-351.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03733-0.

Multicenter comparison of high-dose cytarabine-based regimens versus liposomal daunorubicin and cytarabine (CPX-351) in patients with secondary acute myeloid leukemia

Liposomal daunorubicin/cytarabine (CPX-351) gained FDA approval for secondary AML after demonstrating improved outcomes over daunorubicin and cytarabine (7 + 3). A number of study limitations prompted a comparison of safety/efficacy of CPX-351 against regimens containing a purine analogue and high-dose cytarabine (HIDAC). This retrospective study compared complete response rates with/without count recovery (CR/CRi) between HIDAC-based regimens and CPX-351 in 169 patients with newly diagnosed sAML. The CR/CRi rate was 62.7% in the HIDAC-based therapy arm vs. 47.9% in the CPX-351 arm (p = 0.002 [one-sided for non-inferiority]). Median time to absolute neutrophil and platelet count recovery was shorter after HIDAC-based therapy (18 and 23 days, respectively) compared to CPX-351 (36 and 38 days; p < 0.001). Median overall survival was 9.8 months in the HIDAC-based group and 9.14 months in the CPX-351 group. 30-day mortality was greater with CPX-351 (8.5%) compared to HIDAC-based (1.3%; p = 0.039). These results reveal comparable efficacy and favorable safety with HIDAC-based regimens.

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.

Diagnosis and Treatment of Patients With Acute Myeloid Leukemia With Myelodysplasia-Related Changes (AML-MRC)

Objectives

Acute myeloid leukemia (AML) with myelodysplasia-related changes (AML-MRC) represents a high-risk and somewhat diverse subtype of AML, and substantial confusion exists about the pathologic evaluation needed for diagnosis, which can include the patient’s clinical history, cytogenetic analysis, mutational analysis, and/or morphologic evaluation. Treatment decisions based on incomplete or untimely pathology reports may result in the suboptimal treatment of patients with AML-MRC.

Methods

Using a PubMed search, diagnosis of and treatment options for AML-MRC were investigated.

Results

This article reviews the current diagnostic criteria for AML-MRC, provides guidance on assessments necessary for an AML-MRC diagnosis, summarizes clinical and prognostic features of AML-MRC, and discusses potential therapies for patients with AML-MRC. In addition to conventional chemotherapy, treatment options include CPX-351, a liposomal encapsulation of daunorubicin/cytarabine approved for treatment of adults with AML-MRC; targeted agents for patients with certain mutations/disease characteristics; and lower-intensity therapies for less fit patients.

Conclusions

Given the evolving and complex treatment landscape and the high-risk nature of the AML-MRC population, a clear understanding of the pathology information necessary for AML-MRC diagnosis has become increasingly important to help guide treatment decisions and thereby improve patient outcomes.

Case Report: Allogeneic Stem Cell Transplantation Following Induction With CPX-351 in Patients With Acute Myeloid Leukemia Is Feasible

Acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) and treatment-related acute myeloid leukemia (tAML) after chemotherapy or radiation therapy for other neoplasms are associated with poor outcomes. CPX-351, a dual-drug liposomal encapsulation of daunorubicin and cytarabine, has been shown to improve outcomes in AML-MRC and tAML compared with standard 7+3 regimens. Here we report the cases of four consecutive patients with AML-MRC or tAML who received CPX-351 as outpatient induction therapy immediately followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT). Two patients received allo-HSCT in remission (one in complete remission and one in partial remission) and two patients received allo-HSCT in aplasia (one at 11 days and one at 52 days after the start of induction therapy with CPX-351). With a median follow-up of 188 days after allo-HSCT, all but one patient are alive and two are in remission. Further studies will help define and expand the role of CPX-351 in the treatment of AML-MRC and tAML, especially in patients expected to undergo allo-HSCT.

Pharmacokinetics, drug metabolism, and tissue distribution of CPX-351 in animals

CPX-351, a liposomal encapsulation of cytarabine and daunorubicin at a synergistic 5:1 molar ratio, is indicated for adults with newly diagnosed, therapy-related acute myeloid leukemia or acute myeloid leukemia with myelodysplasia-related changes. In preclinical species, this article demonstrated (1) similar release of cytarabine and daunorubicin by CPX-351 in plasma; (2) similar patterns of metabolism of cytarabine and daunorubicin following administration of CPX-351 versus non-liposomal cytarabine/daunorubicin combination; (3) prolonged tissue exposure to CPX-351; (4) dramatically different tissue distribution of cytarabine and daunorubicin following administration of CPX-351 versus non-liposomal combination (tissue:plasma ratios generally <1 versus >1, respectively); and (5) dramatically lower unbound plasma and tissue concentrations of cytarabine and daunorubicin following administration of CPX-351 versus non-liposomal combination. Together, these results provide insight into the safety profile of CPX-351, as well as mechanisms that drive the improved efficacy observed for CPX-351 versus the conventional 7 + 3 cytarabine/daunorubicin regimen in clinical studies.