Healthcare resource utilization in a phase 3 study of CPX-351 in patients with newly diagnosed high-risk/secondary acute myeloid leukemia

Aims: Treatment of acute myeloid leukemia (AML) requires significant healthcare resource utilization (HRU), including lengthy hospitalizations. In a phase 3 study (NCT01696084), CPX-351 (Vyxeos) showed significant benefits to overall survival and complete remission versus conventional 7 + 3 cytarabine/daunorubicin. This analysis evaluated HRU in patients aged 60-75 years with newly diagnosed high-risk/secondary AML treated with CPX-351 versus 7 + 3 in the phase 3 study.Materials and methods: Patients were randomized to receive up to two induction cycles with CPX-351 or 7 + 3. Responders could receive up to two cycles of consolidation. To normalize HRU to length of treatment, patients were assessed on a per patient-year (PPY) basis. HRU analyses included hospital and intensive care unit (ICU) stays, anti-infective use, transfusions, and white blood cell colony-stimulating factor (CSF).Results: The median (range) total duration of hospitalization was 39 (3-110) days with CPX-351 (n = 153) and 32 (2-83) days with 7 + 3 (n = 151); the estimated durations of hospitalization PPY were 198.4 and 240.5 days, respectively. The median (range) total duration of ICU stays was 0 (0-45) days with CPX-351 and 0 (0-17) days with 7 + 3; the estimated durations of ICU stays PPY were 6.7 and 10.5 days, respectively. When comparing supportive care use during CPX-351 and 7 + 3 treatment, the estimated number PPY of bags of platelets used (24.6 vs 26.9, respectively), bags of packed red blood cells used (13.0 vs 13.9), days of anti-infectives (162.0 vs 159.2), and days of CSF (4.0 vs 2.4) were not notably different.Limitations: This clinical study analysis may not represent real-world HRU patterns or be generalizable to a broader AML population.Conclusions: These PPY data, showing shorter durations of hospitalization and similar use of supportive care with CPX-351 versus 7 + 3, suggest CPX-351 is not associated with increased HRU in older patients with newly diagnosed high-risk/secondary AML.

Digital Droplet PCR is a Specific and Sensitive Tool for Detecting IDH2 Mutations in Acute Myeloid LeuKemia Patients

Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) interfere with cellular metabolism contributing to oncogenesis. Mutations of IDH2 at R140 and R172 residues are observed in 20% of acute myeloid leukemias (AML), and the availability of the IDH2 inhibitor Enasidenib made IDH2 mutational screening a clinical need. The aim of this study was to set a new quantitative polymerase chain reaction (PCR) technique, the drop-off digital droplet PCR (drop-off ddPCR), as a sensitive and accurate tool for detecting IDH2 mutations. With this technique we tested 60 AML patients. Sanger sequencing identified 8/60 (13.5%) mutated cases, while ddPCR and the amplification refractory mutation system (ARMS) PCR, used as a reference technique, identified mutations in 13/60 (21.6%) cases. When the outcome of IDH2-mutated was compared to that of wild-type patients, no significant difference in terms of quality of response, overall survival, or progression-free survival was observed. Finally, we monitored IDH2 mutations during follow-up in nine cases, finding that IDH2 can be considered a valid marker of minimal residual disease (MRD) in 2/3 of our patients. In conclusion, a rapid screening of IDH2 mutations is now a clinical need well satisfied by ddPCR, but the role of IDH2 as a marker for MRD still remains a matter of debate.

Treatment of Relapsed Acute Myeloid Leukemia

Relapse is still a common scenario in acute myeloid leukemia (AML) treatment and occurs in 40–50% of younger and the great majority of elderly patients. The prognosis in relapsed AML patients is generally poor but depends largely on the timing of relapse (early versus late) and the possibility of allogeneic hematopoietic stem cell transplantation (HSCT). At the time of relapse, we again perform a mutational screening and cytogenetic analysis in all AML patients as clonal evolution of disease is frequent. Clinical trials should be first priority in all relapsed patients. In fit patients without prior transplant, we aim to perform HSCT after salvage therapy. In AML patients relapsing after HSCT and good performance status, intensive therapy can be considered with subsequent cellular therapy such as donor lymphocyte infusion (DLI) or a second HSCT. However, less than 20% of these patients are alive after 5 years. For those patients that are unfit, the therapeutic aim is to prolong life with acceptable quality of life. Here, hypomethylating agents (HMA), low-dose AraC (LDAC), and solely cytoreductive therapy with hydroxurea are options depending on first-line therapy. For those patients that have not been treated with venetoclax in first line, the combination therapy of venetoclax with demethylating agents achieves encouraging response rates. Venetoclax is currently also studied in combination with intensive salvage therapy. Importantly, for patients with isocitrate dehydrogenase (IDH) 1/2–mutated AML, ivosidenib, an IDH1 inhibitor, and enasidenib, an IDH2 inhibitor, present well-tolerated options in the setting of refractory or relapsed (r/r) disease even in elderly and heavily pre-treated patients with response rates of 30–40%. Both substances have been approved by the U.S. Food and Drug Administration (FDA) for r/r AML patients with IDH1/2 mutations (but not yet by the European Medicines Agency (EMA)). For patients with FMS-like tyrosine kinase 3 (FLT3) mutations, treatment with the selective FLT3 inhibitor gilteritinib is well tolerated and leads to improved outcome compared with standard salvage therapy. The approval has been granted by the FDA and the EMA. Generally, we would recommend targeted therapy for IDH1/2- and FLT3-mutated AML if available. In order to improve outcome in relapsed AML, it will be important to intelligently combine novel substances with each other as well as chemotherapy in prospective clinical trials. The development of therapies with bispecific antibodies or chimeric antigen receptor T cells (CAR-T) are still in early development.

Liposomal encapsulated cytarabine and daunorubicin (CPX-351) for older patients with acute myeloid leukemia

Acute myeloid leukemia (AML) is a heterogenous disease that predominantly affects older adults. Despite recent advances in therapy, outcomes for AML with conventional induction chemotherapy are worse with advanced age. CPX-351 is a liposomal encapsulated formulation of cytarabine and daunorubicin in a 5:1 molar ratio that has been demonstrated to deliver synergistic ratiometric dosing of these drugs in pre-clinical studies. Early phase studies noted the encapsulated formulation of CPX-351 led to the extended duration of detectable cytarabine and daunorubicin levels compared to conventional chemotherapy, which may contribute to prolonged cytopenias. Further clinical trials demonstrated the safety and efficacy of CPX-351 in older adults, particularly those with secondary AML (sAML). The treatment landscape of AML is evolving with the recent approval of multiple therapeutic agents. Further studies are indicated to evaluate the role of CPX-351 potentially in combination with other targeted drugs.

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.

Novel Therapies in Acute Myeloid Leukemia

OBJECTIVE

To provide a comprehensive review of evidence-based data on the newly approved therapeutic agents in acute myeloid leukemia (AML) with regards to appropriate indications for use, efficacy, and safety.

DATA SOURCES

Published clinical trials and observational studies.

CONCLUSION

Optimal treatment decisions for AML should be personalized based on individual patients' performance status, disease risk as determined by mutational profile, response status, and prior therapies received. While the treatment options have expanded, several questions remain regarding appropriate patient selection, long-term efficacy and safety of these agents, and sequencing of therapies among available options.

IMPLICATIONS FOR NURSING PRACTICE

Nurses need to be familiar with the peculiarities of the administration regimens of newer AML therapies, adopt formal monitoring strategies for side effects that are unique to these agents, and develop a framework to facilitate timeliness of follow-up and monitoring while on these therapies.

Will new agents impact survival in AML?

In recent years, several drugs-including midostaurin, gilteritinib, and gemtuzumab ozogamicin, to name a few-have been approved or reapproved in the United States to treat patients with acute myeloid leukemia (AML). Yet survival rates for younger patients had improved with chemotherapy alone even before the approvals of these new agents. This begs the question whether the new therapies will actually have a positive impact on survival. The 5-year survival rate for older patients has also risen, again without the addition of these new agents. The challenge will be to incorporate new therapies and use them where they will have the greatest impact-major work for clinicians and researchers alike.

CPX-351 (vyxeos) in AML

For decades, the standard induction for patients with acute myeloid leukemia (AML) has been the combination of cytarabine with anthracycline (7 + 3 regimen). In August 2017 the US FDA approved CPX-351 (vyxeos), a liposomal formulation of cytarabine and daunorubicin at a fixed 5:1 molar ratio, for the treatment of adults with newly diagnosed AML with myelodysplasia-related changes (AML-MRC) and therapy-related AML (t-AML). This is the first approved treatment specifically for patients with this subgroup of AML. The approval was based on findings from a multicenter, randomized, open-label, phase III study of CPX-351 Versus 7 + 3 in patients 60-75 years old with newly diagnosed AML-MRC or t-AML. In this study CPX-351 had a higher median OS than 7 + 3 (9.56 vs 5.95 months, HR 0.69; 95% CI: 0.52 to 0.90, p = 0.005). In this profile, we review preclinical and clinical data, and discuss limitations and future directions with CPX-351 use in AML.

[Incorporation of novel agents into the treatment for acute myeloid leukemia]

The mainstay of therapeutic modalities of acute myeloid leukemia (AML) includes intensive chemotherapies and allogeneic hematopoietic cell transplantation. The gold standard of the induction treatment is a regular dose of cytarabine plus anthracycline, and several courses of consolidation therapy are administered. Allogeneic hematopoietic cell transplantation is employed in patients with intermediate-poor risks. No new drugs have been introduced to the treatment of AML for nearly 30 years. However, in 2017, the US Food and Drug Administration approved four novel drugs for treating AML: FLT3 inhibitor midostaurin, IDH2 inhibitor enasidenib, liposomal cytarabine-daunorubicin CPX-351, and revived antibody-drug conjugate gemtuzumab ozogamicin. In Japan, several new agents are also undergoing clinical trials, including Bcl-2 inhibitor venetoclax, CDK9 inhibitor alvocidib, smoothened (SMO) inhibitor glasdegib, hypomethylating agents guadecitabine and azacitidine, NEDD8 inhibitor pevonedistat, and FLT3 inhibitors quizartinib and gilteritinib. These agents will be incorporated into the conventional 7+3 regimen or combined with hypomethylating agents or low-dose cytarabine to improve the therapeutic outcomes of AML.

Outcome of patients aged 60-75 years with newly diagnosed secondary acute myeloid leukemia: A single-institution experience

A recent phase 3 trial showed that outcome of older patients with secondary acute myeloid leukemia (AML) may be improved by a liposomal encapsulation of cytarabine and daunorubicin (CPX‐351). This phase 3 study represents a unique example of prospective data in this rare subgroup providing basis for comparison with real life data. Here, we retrospectively assessed characteristics and outcome of patients aged 60‐75 years with secondary or therapy‐related AML in real life. Out of 218 patients that fulfilled CPX‐351 study criteria, 181 patients (83.0%) received antileukemic treatment either intensive chemotherapy (n = 121) or hypomethylating agents (HMA, n = 60). As compared with patients treated by chemotherapy, HMA‐treated patients were older, had lower WBC, more often AML with antecedent myelodysplastic syndrome and adverse cytogenetic risk. In chemotherapy‐treated patients, the complete response rate was 69%, median overall survival (OS) was 11 months whereas 3‐year and 5‐year OS was 21% and 17%, respectively. In HMA‐treated patients, the complete response rate was 15%, median OS was 11 months whereas 3‐year and 5‐year OS was 15% and 2%, respectively. In conclusion, although outcome of older patients with high‐risk AML is very poor, a significant proportion of patients treated by standard intensive chemotherapy but not HMA are long‐term survivors.

Topoisomerase II inhibitors in AML: past, present, and future

Introduction: Topoisomerase II inhibitors have long been used in the frontline and as salvage therapy for AML, with daunorubicin and idarubicin being prototypical agents in this therapeutic class, classically in combination with nucleoside analogs, e.g. cytarabine. Most recently, several other compounds from this drug class have or are being investigated. Areas covered: The current paper reviews older and newer topoisomerase II inhibitors in clinical development for the treatment of AML. The authors discuss the clinical use of these agents, current trials involving them as well as their safety profile. Important side effects of these medications including therapy-related AML (t-AML) are also covered. Expert opinion: Topoisomerase II inhibitors have helped improve outcomes in AML. Recently, the FDA approved several agents including CPX-351 for the treatment of secondary and t-AML. CPX-351 may have applicability in other high-risk myeloid diseases. Future directions include a combination of these agents with other targeted therapies. Finally, the authors believe that small molecule inhibitors, such as venetoclax and possibly immunotherapy options could also be incorporated to our treatment paradigm in selected patients.

CPX-351: a nanoscale liposomal co-formulation of daunorubicin and cytarabine with unique biodistribution and tumor cell uptake properties

Combination regimens are a standard of care for many cancers. However, components of such regimens are typically first developed individually and subsequently combined using strategies to minimize toxicity. Little or no consideration is given to strategies that potentially maximize efficacy. In contrast, CPX-351 (Vyxeos®) is a dual-drug liposomal encapsulation of cytarabine and daunorubicin that was rationally designed to improve efficacy over the traditional 7+3 cytarabine/daunorubicin chemotherapy regimen for patients with acute myeloid leukemia (AML). The notable clinical efficacy of CPX-351 is achieved through maintenance of a synergistic 5:1 molar ratio of cytarabine and daunorubicin within the liposome after intravenous injection. The CPX-351 liposome, which is formulated to contain bilayers of distearoylphosphatidylcholine, distearoylphosphatidylglycerol, and cholesterol at a 7:2:1 molar ratio and remains in a gel phase at body temperature, provides stability without polyethylene glycol, controlled release of cytarabine and daunorubicin, limited systemic drug distribution, and preferential internalization within malignant myeloblasts in the bone marrow via active uptake of liposomes into cytoplasmic vacuoles. Thus, the CPX-351 liposome protects cytarabine and daunorubicin from metabolism and elimination, while overcoming pharmacokinetic differences between the two agents. In clinical studies, these liposome properties markedly increased the elimination half-life of CPX-351 versus free cytarabine and daunorubicin and maintained a synergistic drug ratio for over 24 hrs after administration. Preferential uptake of liposomes by leukemia cells suggests that relatively large amounts of cytarabine and daunorubicin enter malignant cells via liposomes, potentially bypassing P-glycoprotein-based efflux pumps, which are important mediators of chemotherapy resistance, and contribute to the rapid clearance of leukemia cells from the circulation and bone marrow. These pharmacologic advantages, a direct consequence of properties of the encapsulating liposome, may explain the efficacy of CPX-351 in patients with newly diagnosed high-risk/secondary AML and the reduced drug exposure in off-target tissues that contribute to a manageable safety profile.

Daunorubicin-cytarabine liposome (CPX-351) in the management of newly diagnosed secondary AML: A new twist on an old cocktail

Initial therapy for acute myeloid leukemia (AML) remained stagnant for approximately four decades despite advances in improved understanding of pathogenesis and prognostication of the disease.      Treatment has typically consisted of an anthracycline combined with continuous infusion of cytarabine for 7 days, the "7 + 3" regimen. Attempts have been made to improve on this regimen with modest improvements in response rates but no change in overalll survival, until the recent introduction of mutation-specific agents. However, the re-vamping of the delivery of both daunorubicin and cytarabine in a liposomal encapsulation, known as CPX-351, did show improvements of overall survival compared to traditional 7 + 3 in newly diagnosed secondary and therapy-related AML in patients aged 60-75. This led to the Food and Drug Administration (FDA) approval of the agent for both of these subtypes of AML in August of 2017. Herein we will review the rationale and preclinical development of CPX-351 and discuss the pivotal studies that led to its FDA approval.

[Diagnosis and treatment of acute myeloid leukemia : The updated 2018 Onkopedia Guideline]

In April 2018, an updated version of the previously published guidelines on acute myeloid leukemia (AML) from 2010 and 2017 was released. A revision was necessary because of two positive aspects: First, new data and insights on risk stratification and monitoring, and second, the clinical development and approval of new agents. The modified genetic risk classification allows a more precise distinction of different diagnostic groups and consequently a better matched post-remission treatment. The availability of new targeted drugs such as inhibitors turns genetic analyses from a mere prognostic tool into an instrument for treatment decisions. Several recently approved agents expand the treatment options for AML and raise hope for an improved prognosis and cure in the future.

Liposomal Cytarabine-Daunorubicin (CPX-351) Extravasation: Case Report and Literature Review

BACKGROUND

Liposomal formulation of anthracyclines provide better systemic and organ-specific tolerance, with potential for less local tissue damage during extravasation. Several small series have reported that most liposomal anthracycline extravasations are consistent with irritant injury without tissue necrosis. There have been no reports published regarding the clinical effects of extravasation of liposomal cytarabine-daunorubicin (CPX-351).

CASE REPORT

The patient received CPX-351 for relapsed acute myelogenous leukemia via a left chest wall port-a-catheter. The catheter became dislodged. Once symptoms developed, the infusion was discontinued, with observations demonstrating an 8-cm region of edema, warmth, no erythema, and no drainage. Limited supportive management was performed. Physical examination the following day demonstrated no evidence of necrosis, and erythema resolved completely without additional intervention.

CONCLUSION

CPX-351 extravasation behaving as an irritant is consistent with the reports of other liposomal anthracyclines.

Novel Agents for Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a complex hematological disease characterized by genetic and clinical heterogeneity. Recent advances in the understanding of AML pathogenesis have paved the way for the development of new agents targeting specific molecules or mechanisms that contribute to finally move beyond the current standard of care, which is "3 + 7" regimen. In particular, new therapeutic options such as targeted therapies (midostaurin and enasidenib), monoclonal antibodies (gemtuzumab ozogamicin), and a novel liposomal formulation of cytarabine and daunorubicin (CPX-351) have been recently approved, and will be soon available for the treatment of adult patients with AML. In this review, we will present and describe these recently approved drugs as well as selected novel agents against AML that are currently under investigation, and show the most promising results as monotherapy or in combination with chemotherapy. The selection of these emerging treatments is based on the authors' opinion.

Is the overall survival for older adults with AML finally improving?

Older adults with acute myeloid leukemia (AML) traditionally have very poor survival outcomes. Those who receive only supportive care have worse overall survival than those who undergo treatment, regardless of treatment type, and improvements in overall survival in the last several decades are largely attributable to the increasing decision to treat rather than offer only supportive care. However, there are a few newer agents that appear promising; these include CPX-351 (a liposomal product with cytarabine and daunorubicin), glasdegib (a selective Hedgehog signaling pathway inhibitor), and venetoclax (potent small molecule inhibitor of BCL2). A systematic review and meta-analysis is being completed to help clinicians optimize standard therapies for older AML patients.

CPX-351 exhibits hENT-independent uptake and can be potentiated by fludarabine in leukaemic cells lines and primary refractory AML

CPX-351, a liposomal formulation co-encapsulating cytarabine and daunorubicin (DNR) in a synergistic 5:1 M ratio, has shown favourable response in newly diagnosed elderly high-risk AML. This study assessed intracellular ara-CTP levels following in vitro exposure of human immortalised leukaemic cell lines and primary AML blasts to CPX-351, and investigated fludarabine potentiation of intracellular ara-CTP formation from CPX-351. Comparison of intracellular handling of CPX-351 to cytarabine in HL-60 cells indicated slower conversion to ara-CTP for CPX-351, but equivalent cytotoxicity to cytarabine and combined DNR/cytarabine (DA) at 48 h, mostly likely reflecting the need for intracellular liposome processing to release encapsulated drugs. Further assessment demonstrated cytotoxicity of CPX-351 to be superior to DA at 48 and 72 h in cytarabine-resistant THP-1 cells (p < 0.001), and this effect could not be inhibited upon blockade of human equilibrative nucleoside transporter (hENT) function with dipyridamole. Assessment of Flu-CPX in primary blasts from presentation AML patients (n = 5) demonstrated a more rapid and pronounced potentiation of ara-CTP from CPX-351 than in immortalised cell lines, with 4/5 patients showing significant increases in ara-CTP, notably for those that went on to fail induction and relapse treatment in vivo (n = 3). This suggests a favourable impact on patient outcome from Flu-CPX.

Reformulating acute myeloid leukemia: liposomal cytarabine and daunorubicin (CPX-351) as an emerging therapy for secondary AML

Despite increasing understanding of the pathobiology of acute myeloid leukemia (AML), outcomes remain dismal particularly for patients over the age of 60 years, a population enriched for therapy-related AML (tAML) and secondary AML (sAML). For decades, the standard of care for AML has been the combination of cytarabine and daunorubicin, typically delivered in combination as “7 + 3” induction. In 2017, a liposomal-encapsulated combination of daunorubicin and cytarabine (CPX-351, Vyxeos) was approved by the US Food and Drug Administration (FDA) for use in the treatment of newly diagnosed tAML or AML with myelodysplasia-related changes (AML-MRCs). CPX-351 was designed to deliver a fixed 5:1 molar ratio of cytarabine and daunorubicin, respectively, based on the hypothesis that ratiometric dosing may be more effective than the delivery of either drug at their maximum tolerated dose. In a Phase III trial of older patients with sAML aged 60–75 years, CPX-351 was compared to “7 + 3” and was associated with a higher overall survival, event-free survival, and higher rates of complete remission (CR) and CR with incomplete hematologic recovery (CRi). These data were the basis for the approval of this new drug for use in the treatment of AML, but questions remain regarding how to best administer this agent across AML subgroups. Future directions include evaluating dose intensification with CPX-351, combining this agent with targeted therapies, and better understanding the mechanism of improved responses in tAML and AML-MRC, two entities that are historically less responsive to cytotoxic agents. In summary, CPX-351 offers an exciting new change to the landscape of AML therapy.

The FOSSIL Study: FLAG or standard 7+3 induction therapy in secondary acute myeloid leukemia

Patients with secondary acute myeloid leukemia (sAML) have poor outcomes, with CR/CRi rates of 25-35% with standard 7 + 3 induction chemotherapy, while single center non-comparative analyses suggest promising outcomes with FLAG. We conducted a single-center, retrospective cohort study assessing outcomes in treatment-naïve patients with sAML treated with fludarabine, high-dose cytarabine, and granulocyte colony-stimulating factor (FLAG, n = 40) compared with 7 + 3 (n = 66). Median patient age was 63 years (range: 27-82) in the FLAG group and 60 years (range: 21-76) in the 7 + 3 group (P = 0.968). Patients treated with FLAG achieved higher overall response rates (CR + CRi + MLFS) compared to 7 + 3 (70% vs. 48%, P = 0.043). FLAG was well tolerated, with only one induction death (30-day mortality rate, 3% vs. 8%, P = 0.405) and no cases of cerebellar toxicity. Duration of neutropenia was significantly shorter with FLAG (median 16 vs. 23 days, P < 0.001). Half of the FLAG-treated patients proceeded to consolidative therapy compared with only 27% of those who received 7 + 3 (P = 0.022). Overall survival was comparable between groups (8.5 mos, FLAG vs. 9.1 mos, 7 + 3; P = 0.798). Thus, FLAG may represent a low-cost treatment strategy in sAML that produces higher response rates and promising survival outcomes with minimal treatment-related toxicity. Further studies are required to prospectively compare FLAG to the newly FDA-approved CPX-351 in sAML.

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.

CPX-351: changing the landscape of treatment for patients with secondary acute myeloid leukemia

Multiple novel therapeutic agents against acute myeloid leukemia (AML) have been evaluated in the past several decades without meaningful clinical improvement in outcomes, especially for AML patients age ≥60, where the overall incidence of AML is highest. Therapeutic options mainly consist of hypomethylating agents, ongoing clinical trials and, less commonly, intensive cytotoxic chemotherapy. CPX-351, a novel liposomal formulation which encapsulates cytarabine and daunorubicin in 5:1 molar ratio, has shown promising efficacy, leading to recent US FDA approval for front-line therapy for patients with therapy-related AML and AML with myelodysplasia-related changes based on a large multicenter Phase III clinical trial. This review summarizes the clinical development of CPX-351 as induction therapy.

Persistent cytarabine and daunorubicin exposure after administration of novel liposomal formulation CPX-351: population pharmacokinetic assessment

PURPOSE

CPX-351 is a novel liposomal formulation of cytarabine and daunorubicin which has recently been FDA approved for treatment of acute myeloid leukemia (AML). The current study investigated the pharmacokinetics (PK) of this liposomal formulation.

METHODS

CPX-351 PK data (cytarabine, daunorubicin, and metabolites) from a phase I study of relapsed and refractory AML were used for the analysis. Therapy was given days 1, 3, and 5 of induction (3-134 units/m²). We developed a population PK model to characterize CPX-351 disposition.

RESULTS

39 patients (3589 samples) were evaluated. Liposomal cytarabine and daunorubicin were modeled separately with their respective metabolites. A one-compartment model fit the parent compounds well; the metabolites required two-compartment models. Weight was an independent predictor of liposomal volumes; mild renal and liver dysfunction were not predictors of clearance or volume (maximum creatinine 1.6 mg/dL and total bilirubin 1.8 mg/dL). Liposomal clearances of the two drugs were highly correlated and 1000-fold smaller than published non-encapsulated values supporting prolonged encapsulation in the liposome.

CONCLUSIONS

The PK model demonstrates prolonged exposure to cytarabine and daunorubicin without increases in non-hematologic toxicity that indicates retention of the drugs within the liposome. The unique pharmacology of this formulation may allow for simplified regimens and improved outcomes.

Do cytogenetics affect the post-remission strategy for older patients with AML in CR1?

Data have shown that intensified cytarabine in consolidation for treatment of acute myeloid leukemia (AML) does not equally benefit patients older than 60 years, and older patients experience significantly more neurotoxicity than younger patients. In addition, older patients are more likely to have abnormal or unfavorable cytogenetics, which also tend to confer limited efficacy with intensified cytarabine. This poses a treatment dilemma as to the best post remission therapy to treat older patients. This review explores some of the consolidation treatment strategies and options available for the older AML patient.