A comparison of low-dose cytarabine and hydroxyurea with or without all-trans retinoic acid for acute myeloid leukemia and high-risk myelodysplastic syndrome in patients not considered fit for intensive treatment

Extra-medullary recurrence of myeloid leukemia as myeloid sarcoma after allogeneic stem cell transplantation: impact of conditioning intensity

Myeloid sarcoma (MS) as a solid extra-medullary (EM) manifestation of acute myeloid leukemia (AML), myeloproliferative or myelodysplastic syndromes is a rare presentation of relapse after allogeneic hematopoietic stem cell transplantation (HSCT). The databases of the Departments of Hematology and Oncology of the University Hospitals of Jena and Rostock were screened for patients aged 18 years or older for onset of MS after HSCT for myeloid malignancies between 2002 and 2019. Nineteen patients with MS were identified, the majority of whom had received reduced-intensity conditioning (RIC). The median onset of MS was 425 days after HSCT and the median overall survival since MS was 234 days. Although MS is associated with a poor prognosis, three patients survived more than two years and one more than 11 years after MS onset. These results indicate that RIC protocols may be associated with a higher risk of EM relapse. Since EM relapse occurred in the presence of Graft-versus-host-disease, these observations also demonstrate the limitations of graft-versus-tumor effects after HSCT. In conclusion, occurrence of MS after HSCT is associated with a poor prognosis, as multimodal curative concepts including intensive chemotherapy and another HSCT are often not viable.

The FLAMSA concept-past and future

The FLAMSA reduced intensity (RIC) concept, also known as "sequential therapy", is a conceptual platform for the treatment of leukemia separated in several parts: induction therapy, a sequence of antileukemic and immunosuppressive conditioning for allogeneic stem cell transplantation, and immune restitution supported by donor lymphocyte transfusions. The antileukemic part consists of fludarabine, cytosine arabinoside, and amsacrine (FLAMSA); non-cross reactive agents like fludarabine and amsacrine have been successfully used in cases of refractoriness and relapse. Immunosuppressive conditioning and transplantation follow after only 3 days of rest. This way, the toxicity of allogeneic transplantation could be reduced and the anti-leukemia effects by using allogeneic immune cells could be optimized. This review summarizes available data on efficacy and toxicity of this approach. Further, possible strategies for improvements are discussed in order to provide better chances for elderly and frail patients and patients with advanced and high-risk disease. Among others, several new agents are available that target molecular changes of leukemia for induction of remission and allow for bridging the time after transplantation until adoptive immunotherapy becomes safe and effective.

＜Editors' Choice＞ How to improve outcomes of elderly patients with acute myeloid leukemia: era of excitement

Among elderly patients with acute myeloid leukemia (AML), especially those who are unfit for intensive chemotherapy, a policy of reduced-intensity chemotherapy or conservative observation has been chosen, resulting in unmet medical needs. Clinical trials using anticancer drugs including antimetabolites or drugs targeted to cell cycle-related molecules failed to show superiority over conventional treatments. Recently, drugs targeted to Bcl-2, SMO, FLT3, and IDH1/2 have been shown to prolong overall survival alone or in combination with reduced-intensity chemotherapy. These treatments are likely to reshape the therapeutic landscape of AML, which will be personalized for individual patients based on leukemia genetics.

A proof of concept phase I/II pilot trial of LSD1 inhibition by tranylcypromine combined with ATRA in refractory/relapsed AML patients not eligible for intensive therapy

All-trans-retinoic acid (ATRA) is highly active in acute promyelocytic leukemia but not in other types of acute myeloid leukemia (AML). Previously, we showed that ATRA in combination with Lysine-specific demethylase 1 (LSD1) inhibition by tranylcypromine (TCP) can induce myeloid differentiation in AML blasts. This phase I/II clinical trial investigated the safety and efficacy of TCP/ATRA treatment as salvage therapy for relapsed/refractory (r/r) AML. The combination was evaluated in 18 patients, ineligible for intensive treatment. The overall response rate was 20%, including two complete remissions without hematological recovery and one partial response. We also observed myeloid differentiation upon TCP/ATRA treatment in patients who did not reach clinical remission. Median overall survival (OS) was 3.3 months, and one-year OS 22%. One patient developed an ATRA-induced differentiation syndrome. The most frequently reported adverse events were vertigo and hypotension. TCP plasma levels correlated with intracellular TCP concentration. Increased H3K4me1 and H3k4me2 levels were observed in AML blasts and white blood cells from some TCP/ATRA treated patients. Combined TCP/ATRA treatment can induce differentiation of AML blasts and lead to clinical response in heavily pretreated patients with r/r AML with acceptable toxicity. These findings emphasize the potential of LSD1 inhibition combined with ATRA for AML treatment.

Impact of age and induction therapy on outcome of 180 adult patients with acute myeloid leukemia; retrospective analysis and literature review

The prognosis of acute myeloid leukemia (AML) remains poor. Among 180 patients, the median age was 53 (14-88) years. The overall 2-year disease free survival (DFS) was 28.6% (+/- 3.4), 47.7% (+/- 6.6%) for ≤ 40, 23.6% (+/- 5.8%) for 41–60 and 11.7% (+/- 4.2%) for ≥61 (p< 0.0001). The overall 2-year survival (OS) was 45.3% (+/- 3.8%), 78.6% (+/- 5.5%) for ≤40, 43.5% (+/- 6.9%) for 41–60 and 15.8% (+/- 4.8%) for ≥61 (p< 0.0001). Induction outcome of ≥61 was best in high dose chemotherapy (HDC) group (p < 0.0001). Only those ≤40 had durable DFS and OS. HDC appears to improve the outcome of older AML patients.

The PI3K-Akt-mTOR Signaling Pathway in Human Acute Myeloid Leukemia (AML) Cells

Acute myeloid leukemia (AML) is a heterogeneous group of diseases characterized by uncontrolled proliferation of hematopoietic stem cells in the bone marrow. Malignant cell growth is characterized by disruption of normal intracellular signaling, caused by mutations or aberrant external signaling. The phosphoinositide 3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) pathway (PI3K-Akt-mTOR pathway) is among one of the intracellular pathways aberrantly upregulated in cancers including AML. Activation of this pathway seems important in leukemogenesis, and given the central role of this pathway in metabolism, the bioenergetics of AML cells may depend on downstream signaling within this pathway. Furthermore, observations suggest that constitutive activation of the PI3K-Akt-mTOR pathway differs between patients, and that increased activity within this pathway is an adverse prognostic parameter in AML. Pharmacological targeting of the PI3K-Akt-mTOR pathway with specific inhibitors results in suppression of leukemic cell growth. However, AML patients seem to differ regarding their susceptibility to various small-molecule inhibitors, reflecting biological heterogeneity in the intracellular signaling status. These findings should be further investigated in both preclinical and clinical settings, along with the potential use of this pathway as a prognostic biomarker, both in patients receiving intensive curative AML treatment and in elderly/unfit receiving AML-stabilizing treatment.

Selection of initial therapy for newly-diagnosed adult acute myeloid leukemia: Limitations of predictive models

Acute myeloid leukemia (AML) remains difficult to treat: despite multiagent chemotherapy, allogeneic hematopoietic cell transplantation, and several newly approved agents, many patients will not be alive and in remission 3 years after diagnosis. However, with more agents available there are more options and a corresponding need to choose among them. Doing so is complicated by the molecular diversity of AML and the older age of many patients, predisposing them to both treatment-related mortality and, more commonly, resistance to treatment. There is no shortage of scoring systems to identify patients at high risk of early death or treatment resistance after conventional AML induction chemotherapy. As we point out here, their accuracy is limited. Furthermore, without periodic recalibration to account for new therapies and changes in supportive care, the accuracy of any prediction model will decrease over time. The limitations we describe here are important for clinicians to be aware of.

Performance of prognostic scoring systems in elderly patients with acute myeloid leukaemia on intensive chemotherapy: A PETHEMA registry study

Selection of elderly patients (aged ≥60 years) for intensive chemotherapy treatment of acute myeloblastic leukaemia (AML) remains challenging. Several cooperative groups such as Acute Leukaemia French Association (ALFA), Haematological Oncology Clinical Studies Group (HOCSG) and MD Anderson Cancer Center (MDACC) have developed predictive models to select those patients who can benefit from intensive chemotherapy. Our purpose is to validate and compare these three models in a cohort of patients treated in real-life setting. For this, a total of 1724 elderly AML patients and treated with intensive chemotherapy regimens were identified in the PETHEMA registry. Median age was 67.2 years (range, 60-84,9) and median overall survival [OS] 9 months (95 % confidence interval [CI], 8.2-9.7). Taking into account the ALFA group's model, patients likely to benefit from intensive chemotherapy had longer OS (14 months, 95 % CI 12.3-15.7) than those unlikely to benefit (5 months, 95 % CI 4.1-5.9; p < 0.001). Significant differences in OS were observed between patients with favourable risk (17 months, 95 % CI 13.2-20.7), intermediate risk (11 months, 95 % CI 9.3-12.6) and adverse risk (6 months, 95 % CI 5.1-6.4; p < 0.001) according to the HOCSG model. No significant differences in OS were observed between patients with 0, 1, 2 or ≥3 points according to the MDACC model. However, when patients with ≥1 point were compared with those with 0 points, median OS was significantly longer in the latter [15 months (95 % CI 12.1-17.8) vs 7 (95 % CI 5.7-8.5)]. This retrospective study validates predictive models proposed by the ALFA, HOCSG and MDACC groups in this real-life cohort.

Low-intensity regimens versus standard-intensity induction strategies in acute myeloid leukemia

Treatment options for elderly patients with acute myeloid leukemia (AML) remain limited. In this age group, AML is frequently associated with poor-risk features, while patients’ present comorbidities and reduced functional reserves. As such, intensive chemotherapy (ICT) is frequently too toxic or ineffective in elderly patients and is restricted to a select minority, though it is standard therapy for the youngest and fittest patients or for those belonging to either the favorable or intermediate-risk groups. The use of hypomethylating agents represent an effective alternative for patients who are unfit for ICT, yet the results remain unsatisfactory. In recent years, prognostic scores were developed that include geriatric assessment tools and improved risk-stratification. In addition, several effective new drugs have emerged. The combination of these drugs with hypomethylating agents or low-dose cytarabine has produced encouraging preliminary results that may change standard practices and offer an alternative to the dilemma of ICT versus low-intensity therapies.

Safety and efficacy of talacotuzumab plus decitabine or decitabine alone in patients with acute myeloid leukemia not eligible for chemotherapy: results from a multicenter, randomized, phase 2/3 study

Talacotuzumab, a humanized anti-CD123 monoclonal antibody, was evaluated in combination with decitabine in elderly patients with acute myeloid leukemia (AML) not eligible for intensive chemotherapy. A multicenter, phase 2/3 study was initiated to determine the recommended phase 2 dose (RP2D) of talacotuzumab (Part A) followed by an open-label, randomized comparison of talacotuzumab in combination with decitabine versus decitabine alone to assess achievement of complete response (CR) and overall survival (OS) in Part B. Ten patients were enrolled in Part A and 316 in Part B; the results presented here are based on a database lock on January 25, 2018. Part A confirmed the RP2D of talacotuzumab to be 9 mg/kg. In Part B, CR was achieved in 12/80 (15%) patients receiving combination therapy and in 9/82 (11%) patients receiving decitabine alone (odds ratio: 1.4; 95% confidence interval [CI]: 0.6-3.6; p = 0.44). Median (95% CI) OS was 5.36 (4.27-7.95) months for combination therapy versus 7.26 (6.47-8.64) months for decitabine alone (hazard ratio: 1.04; 95% CI: 0.79-1.37; p = 0.78). Combination therapy showed no improvement in efficacy versus decitabine alone, resulting in the Independent Data Monitoring Committee's recommendation of early termination of enrollment and discontinuation of talacotuzumab treatment.

A Remarkable Remission: Treating HMA Refractory Transforming MDS with Single-Agent Low-Dose Cytarabine Leading to an Ongoing Six-Year OS

Hypomethylating agents (HMA) are the standard of care for patients ≥65 years with intermediate-high risk myelodysplastic syndrome (MDS) unsuitable for intensive therapy or stem cell transplant (SCT). However, many patients will develop relapse/refractory disease, at which point limited treatment options remain. There has been a lot of research into investigational agents following HMA failure, especially now into targeted therapy, but there is no final consensus or convincing data to guide clinicians. Low-dose cytarabine (LDAC) has been in the armamentarium for some time, but the value of LDAC is judged differently by various guidelines. Nevertheless, in a subgroup of patients who fail on a HMA and wish to continue treatment, LDAC may still have the potential to improve overall survival (OS). In this case report, we present an 85-year-old gentleman with HMA refractory high-risk/transforming MDS (with a noncomplex karyotype) achieving an ongoing six-year OS with single-agent second-line LDAC. LDAC may therefore still be considered by clinicians as a therapeutic option, but when available, patients should be enrolled on a clinical trial.

How I treat acute myeloid leukemia in the era of new drugs

The acute myeloid leukemia (AML) treatment landscape has changed substantially since 2017. New targeted drugs have emerged, including venetoclax to target B-cell lymphoma 2, midostaurin and gilteritinib to target FLT3, and ivosidenib and enasidenib to target mutant isocitrate dehydrogenase 1 and 2, respectively. Other additions include reapproval of gemtuzumab ozogomycin to target CD33, glasdegib to target the hedgehog pathway, and a liposomal formulation of daunorubicin and cytarabine (CPX-351). Genomically heterogeneous AML has a tendency to evolve, particularly under selective treatment pressure. For decades, treatment decisions have largely centered around chemotherapy drug intensity. Physicians now have access to an increasing number of drugs with novel mechanisms of action and distinctive side-effect profiles. Key issues faced by hematologists in this era of new drugs include (1) the timely identification of actionable mutations at diagnosis and at relapse; (2) deciding which drug to use among several therapeutic options; and (3) increasing awareness of how to anticipate, mitigate, and manage common complications associated with these new agents. This article will use 3 case presentations to discuss some of the new treatment challenges encountered in AML management, with the goal of providing practical guidance to aid the practicing physician.

Efficacy and Safety of Metronomic Chemotherapy Versus Palliative Hydroxyurea in Unfit Acute Myeloid Leukemia Patients: A Multicenter, Open-Label Randomized Controlled Trial

Background:

Management of unfit AML patients is a therapeutic challenge. Most hematologists tend to avoid aggressive treatment leaving patients with a choice of best supportive care. We hypothesized that metronomic chemotherapy could be an alternative treatment for unfit AML patients.

Methods:

A multi-center randomized controlled trial was conducted in seven university-affiliated hospitals in Thailand. Unfit AML patients were recruited and followed up from December 2014 to December 2017. Patients were randomly assigned to receive either metronomic chemotherapy or palliative hydroxyurea. Overall survival rates were compared using Cox’s proportional hazard survival analysis.

Results:

A total of 81 eligible patients were randomly allocated and included for ITT analysis. The OS rate was higher in group receiving metronomic chemotherapy than in group receiving palliative treatment at 6 and 12 months with borderline significance (6 months HR 0.60; 95%CI 0.36, 1.02; p-value 0.060; 12 months: HR 0.66; 95%CI 0.41, 1.08; p-value 0.097).

Conclusion:

Metronomic chemotherapy could prolong survival time of unfit AML patients, especially in the first 12 months after diagnosis without increasing treatment-associated adverse events.

Prolonged administration of low-dose cytarabine and thioguanine in elderly patients with acute myeloid leukaemia (AML) achieves high complete remission rates and prolonged survival

The prognosis of AML in elderly patients is poor and research into novel therapeutic approaches is urgently needed. This study examined the use of low-dose chemotherapy with cytarabine and thioguanine administered in repetitive cycles in 62 elderly patients with newly diagnosed or relapsed/refractory AML. The overall response rate was 58% in the total cohort. Response rates (CR/CRi) were significantly higher in patients with newly diagnosed AML (74%) compared to patients with relapsed/refractory disease (25%, p = .0004). Kaplan-Meier estimate of overall survival was 289 days (95% CI; 183-395 days) with a relapse rate of 65.7%. The induction mortality rate was 16.1% with treatment successfully undertaken in the outpatient setting. Similar clinical outcomes were observed in a retrospective analysis of a second cohort of 25 AML patients treated at a different site. These results support the use of a sustained low intensity chemotherapy approach as a therapeutic option for elderly patients with AML.

Valproate and Retinoic Acid in Combination With Decitabine in Elderly Nonfit Patients With Acute Myeloid Leukemia: Results of a Multicenter, Randomized, 2 × 2, Phase II Trial

PURPOSE

DNA-hypomethylating agents are studied in combination with other epigenetic drugs, such as histone deacetylase inhibitors or differentiation inducers (eg, retinoids), in myeloid neoplasias. A randomized, phase II trial with a 2 × 2 factorial design was conducted to investigate the effects of the histone deacetylase inhibitor valproate and all-trans retinoic acid (ATRA) in treatment-naive elderly patients with acute myeloid leukemia (AML).

PATIENTS AND METHODS

Two hundred patients (median age, 76 years; range, 61-92 years) ineligible for induction chemotherapy received decitabine (20 mg/m² intravenously, days 1 to 5) alone (n = 47) or in combination with valproate (n = 57), ATRA (n = 46), or valproate + ATRA (n = 50). The primary endpoint was objective response, defined as complete and partial remission, tested at a one-sided significance level of α = .10. Key secondary endpoints were overall survival, event-free survival, and progression-free survival and safety.

RESULTS

The addition of ATRA resulted in a higher remission rate (21.9% with ATRA v 13.5% without ATRA; odds ratio, 1.80; 95% CI, 0.86 to 3.79; one-sided P = .06). For valproate, no effect was observed (17.8% with valproate v 17.2% without valproate; odds ratio, 1.06; 95% CI, 0.51 to 2.21; one-sided P = .44). Median overall survival was 8.2 months with ATRA v 5.1 months without ATRA (hazard ratio, 0.65; 95% CI, 0.48 to 0.89; two-sided P = .006). Improved survival was observed across risk groups, including patients with adverse cytogenetics, and was associated with longer response duration. With valproate, no survival difference was observed. Toxicities were predominantly hematologic, without relevant differences between the 4 arms.

CONCLUSION

The addition of ATRA to decitabine resulted in a higher remission rate and a clinically meaningful survival extension in these patients with difficult-to-treat disease, without added toxicity.

Current treatment preferences in acute myeloid leukemia: a survey in Brazil

INTRODUCTION

Most adults with acute myeloid leukemia (AML) will eventually relapse from their disease. The combination of 7-day cytarabine and an anthracycline on days 1-3 (the so called "7 + 3" regimen) can be considered standard of care of younger patients with AML. However, the treatment of the elderly ineligible for intensive chemotherapy remains a challenge. Low-dose of subcutaneous cytarabine or hypomethylating agents (HMA) have been studied this group. There are no studies investigating physician practice variation in treating AML in Brazil.

METHODS

We developed a survey with ten questions in order to explore the approach to AML in Brazil.

RESULTS

The sample size comprised 100 hematologists. Most reported regular (63%) or occasional (29%) treatment of AML patients. Karyotype analysis and polymerase chain reaction were available in 88% and 71% of institutions, respectively. Next generation sequencing analysis was used in 7% of instituitions. Younger patients receive the "7 + 3" protocol with continuous infusion of cytarabine and anthracycline in 98% of cases. The preferred anthracycline is daunorubicin (64%), followed by idarubicin (34%). The most prescribed daunorubicin dose was 60 mg/m² (56%). Consolidation after CR with high cytarabine doses (HIDAC) was indicated by 84% of hematologists and 70% use 3 g/m² twice a day for 3 days. Elderly and unfit patients received HMA (47%) as the preferred treatment.

CONCLUSION

We showed that the most prevalent AML treatments were according to current guidelines. There is room to improve on the availability of diagnostic tools and the capacity to perform bone marrow transplantation.

Targeted Alpha-Particle Therapy for Hematologic Malignancies

The short range and high linear energy transfer of α-particles offer the potential for efficient tumor killing while sparing normal bystander cells. Hematologic malignancies are ideally suited to targeted α-particle therapy (TAT) due to easy accessibility of malignant cells in blood, bone marrow, lymph nodes, and spleen as well as their radiosensitivity. Most clinical trials using α-particle therapy for hematologic malignancies have focused on acute myeloid leukemia (AML); however, preclinical studies have shown activity against other diseases such as non-Hodgkin's lymphoma and multiple myeloma. To date, the short-lived radionuclide bismuth-213 (²¹³Bi) and its parent actinium-225 (²²⁵Ac) have been used clinically, but trials with astatinie-211 (²¹¹At) have recently begun, and thorium-227 (²²⁷Th) has shown promising preclinical results. Lintuzumab is a humanized monoclonal antibody that targets the cell surface antigen CD33, which is expressed on the vast majority of AML cells. Initial studies showed that ²¹³Bi-labeled lintuzumab had antileukemic activity and could produce remissions after partial cytoreduction with cytarabine. An initial phase I trial demonstrated that a single infusion of ²²⁵Ac-lintuzumab could be given safely at doses upto 111 kBq/kg with antileukemic activity across all dose levels. A second phase I study showed that fractionated-dose ²²⁵Ac-lintuzumab could be safely combined with low-dose cytarabine and produced objective responses in 28% of older patients with untreated AML. In a phase II study, treatment with ²²⁵Ac-lintuzumab monotherapy for a similar patient population resulted in remission in 69% of patients receiving two fractions of 74 kBq/kg and 22% of patients receiving two 55.5-kBq/kg fractions. Additionally, TAT may be useful in intensifying antileukemic therapy prior to hematopoietic cell transplantation, and pretargeting strategies offer the possibility for improved tumor-to-normal organ dose ratios.

RAF Kinase Inhibitor Protein in Myeloid Leukemogenesis

RAF kinase inhibitor protein (RKIP) is an essential regulator of intracellular signaling. A somatic loss of RKIP expression is a frequent event in solid human cancers, and a role of RKIP as metastasis-suppressor is widely accepted nowadays. Recently, RKIP loss has been described in acute myeloid leukemia (AML) and a series of other myeloid neoplasias (MNs). Functional in vitro and in vivo experiments revealed that RKIP is an essential player within the development of these liquid tumors; however, the respective role of RKIP seems to be complex and multi-faceted. In this review, we will summarize the current knowledge about RKIP in myeloid leukemogenesis. We will initially describe its involvement in physiologic hematopoiesis, and will then proceed to discuss its role in the development of AML and other MNs. Finally, we will discuss potential therapeutic implications arising thereof.

[What is recommended in the treatment of acute myeloid leukemia?]

Acute myeloid leukemia (AML) is characterized by a malignant transformation and proliferation of myeloid progenitor cells that cause a replacement of normal hematopoiesis. Diagnostic workup for AML includes cytogenetic analysis and mutational screening covering frequently mutated genes in AML. The genetic analysis is required for risk stratification and treatment decisions. Very recently, three novel drugs have been approved for patients who can be intensively treated: a tyrosine kinase inhibitor (midostaurin) for patients with FLT3 mutations, a liposomal formulation of chemotherapy (CPX) for patients with features of secondary AML, and a CD33 antibody-drug conjugate (gemtuzumab-ozogamicin) for AML with CD33 expression. Allogeneic stem cell transplantation remains an important treatment strategy for patients with intermediate- or high-risk AML and for patients with relapsed AML. For elderly patients who cannot undergo intensive treatment, demethylating agents are the treatment of choice. The aim is to prolong life expectancy with acceptable quality of life. In recent clinical trials, novel drugs have shown promising results in this patient population. Some of these drugs have already been approved in the US. Among these drugs are the Bcl‑2 inhibitor venetoclax, which is already approved in Germany for chronic lymphatic leukemia, as well as IDH1/IDH2 inhibitors (the latter for patients with IDH1/IDH2 mutated AML). Acute promyelocytic leukemia represents a special type of AML that should be treated with a combination of all-trans retinoic acid and arsenic trioxide leading to excellent outcome.

Venetoclax for the treatment of newly diagnosed acute myeloid leukemia in patients who are ineligible for intensive chemotherapy

Acute myeloid leukemia (AML) is an aggressive hematological malignancy with a globally poor outcome, especially in patients ineligible for intensive chemotherapy. Until recently, therapeutic options for these patients included low-dose cytarabine (LDAC) or the hypomethylating agents (HMA) azacitidine and decitabine, which have historically provided only short-lived and modest benefits. The oral B-cell lymphoma 2 inhibitor, venetoclax, Venetoclax, an oral B-cell lymphoma 2 (BCL2) inhibitor, is now approved by the USA Food and Drug Administration (FDA) in combination with LDAC or HMA in older AML patients ineligible for intensive chemotherapy. Is now approved by the US Food and Drug Administration for this indication. In the pivotal clinical trials evaluating venetoclax either in combination with LDAC or with HMA, the rates of complete remission (CR) plus CR with incomplete hematological recovery were 54% and 67%, respectively and the median overall survival (OS) was 10.4 months and 17.5 months, respectively, comparing favorably with outcomes in clinical trials evaluating single-agent LDAC or HMA. The most common adverse events with venetoclax combinations are gastrointestinal symptoms, which are primarily low grade and easily manageable, and myelosuppression, which may require delays between cycles, granulocyte colony-stimulating factor (G-CSF) administration, or decreased duration of venetoclax administration per cycle. A bone marrow assessment after the first cycle of treatment is critical to determine dosing and timing of subsequent cycles, as most patients will achieve their best response after one cycle. Appropriate prophylactic measures can reduce the risk of venetoclax-induced tumor lysis syndrome. In this review, we present clinical data from the pivotal trials evaluating venetoclax-based combinations in older patients ineligible for intensive chemotherapy, and provide practical recommendations for the prevention and management of adverse events associated with venetoclax.

Cyclin-dependent kinase (CDK) 9 and 4/6 inhibitors in acute myeloid leukemia (AML): a promising therapeutic approach

Introduction: Despite advancements over the last 2 years, outcomes for acute myeloid leukemia (AML) are poor; however, a greater comprehension of disease mechanisms has driven the investigation of new targeted treatments. Cyclin-dependent kinases (CDKs) regulate cell cycle progression, transcription and DNA repair, and are aberrantly expressed in AML. Targeting the CDK pathway is an emerging promising therapeutic strategy in AML.Areas covered: We describe the rationale for targeting CDK9 and CDK4/6, the ongoing preclinical and clinical trials and the potential of these inhibitors in AML. Our analysis included an extensive literature search via the Pubmed database and clinicaltrials.gov (March to August, 2019).Expert opinion: While CDK4/6 inhibitors are early in development for AML, CDK9 inhibition with alvocidib has encouraging clinical activity in newly diagnosed and relapsed/refractory AML. Preclinical data suggests that leukemic MCL-1 dependence may predict response to alvocidib. Moreover, MCL-1 plays a key role in resistance to BCL-2 inhibition with venetoclax. Investigational strategies of concomitant BCL-2 and CDK9 inhibition represent a promising therapeutic platform for AML. Furthermore, preclinical data suggests that CDK4/6 inhibition has selective activity in patients with KMT2A-rearrangements and FLT3 mutations. Incorporation of CDK9 and 4/6 inhibitors into the existing therapeutic armamentarium may improve outcomes in AML.

Glasdegib in the treatment of acute myeloid leukemia

Pharmacologic inhibition of the Hedgehog pathway significantly enhanced the sensitivity of leukemic cells to cytotoxic drugs. Glasdegib (PF-04449913; DAURISMO™) is a potent and selective oral inhibitor of the Hedgehog signaling pathway with clinical activity in patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), particularly in combination with chemotherapy. The results of Phase Ib/II studies evaluating safety and efficacy of glasdegib combined with chemotherapy in previously untreated patients with AML or high-risk myelodysplastic syndrome have recently been published. In the BRIGHT AML 1003 study, glasdegib in combination with low-dose cytarabine (LDAC) was well tolerated and demonstrated a significant 54% reduction in mortality compared with LDAC for AML patients. In 2018, the US FDA approved glasdegib in combination with LDAC for the treatment of newly diagnosed patients with AML who are 75 years old or older or who have co-morbidities that preclude use of intensive induction chemotherapy.

Anti-leukemic effects of all-trans retinoic acid in combination with Daratumumab in acute myeloid leukemia

Acute myeloid leukemia (AML) remains a significant health problem, with poor outcomes despite chemotherapy and bone marrow transplants. Although one form of AML, acute promyelocytic leukemia (APL), is successfully treated with all-trans retinoic acid (ATRA), this drug is seemingly ineffective against all other forms of AML. Here, we show that ATRA up-regulates CD38 expression on AML blasts to sufficient levels that promote antibody-mediated fratricide following the addition of anti-CD38 daratumumab (DARA). The combination of ATRA plus DARA induced Fc-dependent conjugate formation and cytotoxicity among AML blasts in vitro. Combination treatment also led to reduction in tumor volume and resulted in increased overall survival in murine engraftment models of AML. These results suggest that, although ATRA does not induce differentiation of non-APL, it may be effective as a therapy in conjunction with DARA.

Targeted Alpha-Particle Therapy for Hematologic Malignancies

INTRODUCTION

The short range and high linear energy transfer of α-particles offer the potential for efficient tumor killing while sparing surrounding normal cells. Hematologic malignancies are ideally suited to targeted α-therapy because of easy accessibility of malignant cells in blood and bone marrow and their radiosensitivity.

METHODS

A series of clinical trials were conducted to assess the safety and antileukemic effects of lintuzumab, an anti-CD33 antibody, labeled with the α-emitters bismuth-213 (²¹³Bi) and actinium-225 (²²⁵Ac) in patients with acute myeloid leukemia (AML).

RESULTS

Initial studies showed that ²¹³Bi-lintuzumab had antileukemic activity and could produce remissions after partial cytoreduction with cytarabine. A phase I trial demonstrated that a single infusion of ²²⁵Ac-lintuzumab could be given safely at doses up to 111 kBq/kg with antileukemic activity at all dose levels studied. A second phase I study showed that 28% of older patients with untreated AML had objective responses after receiving fractionated-dose ²²⁵Ac-lintuzumab and low-dose cytarabine. A phase II study of ²²⁵Ac-lintuzumab monotherapy in this population produced remissions in 69% of patients receiving two fractions of 74 kBq/kg and 22% of patients receiving two 55.5-kBq/kg fractions.

CONCLUSIONS

Studies with ²¹³Bi-lintuzumab provided proof of principle for systemically administered α-particle therapy. ²²⁵Ac-lintuzumab was active against advanced AML and produced remissions in older patients with untreated AML in combination with low-dose cytarabine and as a single agent. These studies provide the rationale for development of ²²⁵Ac-lintuzumab in combination with a variety of agents in AML and in other hematologic malignancies such as myelodysplastic syndrome and multiple myeloma.

Venetoclax-based therapies for acute myeloid leukemia

The prognosis of adult acute myeloid leukemia (AML) remains poor, with the long-term survival rate less than 50%. However, the current paradigms of treatment are changing through a better understanding of the disease genetics and pathophysiology. Since 2017, eight new drugs have been approved by the U.S. Food and Drug Administration for the treatment of AML, including the FLT3 inhibitors midostaurin and gilteritinib, the IDH inhibitors ivosidenib and enasidenib, the anti-CD33 monoclonal antibody gemtuzumab ozogamicin, liposomal daunorubicin and cytarabine, the hedgehog pathway inhibitor glasdegib and the BCL-2 inhibitor venetoclax. Preclinical data demonstrated the anti-leukemic efficacy of venetoclax in AML and its synergy when combined with hypomethylating agents or chemotherapy agents. Clinical trials have demonstrated the clinical benefit of venetoclax-based therapies in newly diagnosed AML, leading to the recent FDA approval of venetoclax in combination with hypomethylating agents or low-dose cytarabine for older adults with newly diagnosed AML. Herein, we focus on the role of single-agent BCL-2 inhibition in AML and review the clinical studies of venetoclax-based combination regimens and the evolving mechanisms of resistance.

Diagnostic and prognostic significance of serum CD26 level in Asian women with high-grade serous ovarian carcinoma

Aim: The aim of this study was to reveal the diagnostic and prognostic significance of serum CD26 level in high-grade serous ovarian carcinoma women in China. Methods: There were 229 high-grade serous ovarian carcinoma women and 365 controls. Baseline serum CD26 level was measured using ELISA. A 36-month post-operation follow-up was performed. Results: Baseline serum CD26 level ≤601.5 pg/ml was associated with the increased risk of ovarian carcinoma (OR: 1.67; 95% CI: 1.20-2.32). Baseline serum level of CD26 ≤589.7 pg/ml was related to the elevated risk of cancer death (HR: 1.33; 95% CI: 1.04-1.69). Conclusion: Baseline serum CD26 level might be an independent diagnostic and prognostic marker for high-grade serous ovarian carcinoma.

Evaluating venetoclax and its potential in treatment-naïve acute myeloid leukemia

Venetoclax (ABT-199), a BH3-mimetic and selective BCL-2 inhibitor, was recently approved by the US Food and Drug Administration (FDA) for the treatment of acute myeloid leukemia (AML) in adult patients aged 75 years or older, or otherwise unable to tolerate intensive induction chemotherapy, in combination with either hypomethylating agents or low-dose cytarabine. In this review article, we discuss venetoclax’s mechanism of action, in relation to both the BCL-2 protein family in general and BH3-mimetic activity in particular. We then outline the pharmacological advances that preceded and facilitated its development, as well as providing an overview of key preclinical and clinical studies which lead to its use first in chronic lymphoid leukemia (CLL), then in small lymphocytic leukemia (SLL), and subsequently in AML. Finally, we seek to offer an overview of the challenges and opportunities encountered as venetoclax moves into more widespread use, including its use and activity against leukemia initiating cells and oxidative phosphorylation.

New drugs creating new challenges in acute myeloid leukemia

The therapeutic landscape is rapidly changing, with eight new drugs approved by the Food and Drug Administration within the last 2 years, including midostaurin and gilteritinib for FLT3 mutant newly diagnosed and relapsed/refractory (R/R) acute myeloid leukemia (AML), respectively; CPX-351 (liposomal cytarabine and daunorubicin) for therapy-related AML and AML with myelodysplasia-related changes; gemtuzumab ozogamicin (anti-CD33 monoclonal antibody conjugated with calicheamicin) for newly diagnosed and R/R CD33-positive AML; enasidenib and ivosidenib for IDH2 and IDH1 mutant R/R AML, respectively. Novel therapies have also emerged for newly diagnosed AML in adults who are age 75 years or older, or who have comorbidities that preclude the use of intensive induction chemotherapy. These include venetoclax (BCL-2 inhibitor) in combination with hypomethylating agents (azacitidine or decitabine) or low-dose cytarabine (LDAC), and glasdegib (sonic hedgehog pathway inhibitor) in combination with LDAC. This flurry of new drug approvals has markedly altered the treatment landscape in AML and provided new opportunities, as well as new challenges for treating clinicians. This review will focus on how these drugs might shape clinical practice and the hurdles likely to be faced by new therapies seeking entry into this dynamic and rapidly changing therapeutic landscape.

Importance of prognostic stratification via gene mutation analysis in elderly patients with acute myelogenous leukemia

INTRODUCTION

Acute myelogenous leukemia (AML) in elderly patients is associated with an increased incidence of complications and treatment-related toxicity because of the frequency of comorbid disease and age-related deterioration in organ function. Despite advances in AML treatment in recent years, elderly patients have experienced limited benefit, and their outcomes remain poor. This study aimed to perform a comprehensive gene mutation analysis in elderly AML patients and identify gene mutations that could serve as prognostic factors.

METHODS

An analysis of gene mutations was performed for 281 AML patients, including 98 elderly patients aged 65 years or above.

RESULTS

Compared to younger AML patients, elderly patients showed a higher frequency of the following gene mutations: TP53 (P = 0.026), PTPN11 (P = 0.006), RUNX1 (P = 0.024), TET2 (P = 0.002), and ASXL1 (P = 0.023). The complete remission rate was significantly lower in DNMT3A mutation-positive cases (4.26%, P = 0.011) and TP53 mutation-positive cases (2.13%, P = 0.031) than in negative cases. The overall survival rate was significantly poorer in cases with FLT3-ITD (P = 0.003), DNMT3A (P = 0.033), or TP53 mutation (P < 0.001). Conversely, cases with PTPN11 mutation (P = 0.014) had a significantly more favorable prognosis. In multivariate analysis, FLT3-ITD (P = 0.011) and TP53 mutation positivity (P = 0.002) were independent poor prognostic factors, as were a performance status of 3 or above (P < 0.001) and poor cytogenetic prognosis (P = 0.001). In contrast, PTPN11 mutation positivity (P = 0.023) was an independent favorable prognosis factor.

CONCLUSION

Analysis of gene mutations in elderly AML patients is very important, not only for establishing prognosis, but also for introducing appropriate molecular-targeted treatments.

Venetoclax Combined With Low-Dose Cytarabine for Previously Untreated Patients With Acute Myeloid Leukemia: Results From a Phase Ib/II Study

PURPOSE

Effective treatment options are limited for patients with acute myeloid leukemia (AML) who cannot tolerate intensive chemotherapy. An international phase Ib/II study evaluated the safety and preliminary efficacy of venetoclax, a selective B-cell leukemia/lymphoma-2 inhibitor, together with low-dose cytarabine (LDAC) in older adults with AML.

PATIENTS AND METHODS

Adults 60 years or older with previously untreated AML ineligible for intensive chemotherapy were enrolled. Prior treatment of myelodysplastic syndrome, including hypomethylating agents (HMA), was permitted. Eighty-two patients were treated at the recommended phase II dose: venetoclax 600 mg per day orally in 28-day cycles, with LDAC (20 mg/m² per day) administered subcutaneously on days 1 to 10. Key end points were tolerability, safety, response rates, duration of response (DOR), and overall survival (OS).

RESULTS

Median age was 74 years (range, 63 to 90 years), 49% had secondary AML, 29% had prior HMA treatment, and 32% had poor-risk cytogenetic features. Common grade 3 or greater adverse events were febrile neutropenia (42%), thrombocytopenia (38%), and WBC count decreased (34%). Early (30-day) mortality was 6%. Fifty-four percent achieved complete remission (CR)/CR with incomplete blood count recovery (median time to first response, 1.4 months). The median OS was 10.1 months (95% CI, 5.7 to 14.2), and median DOR was 8.1 months (95% CI, 5.3 to 14.9 months). Among patients without prior HMA exposure, CR/CR with incomplete blood count recovery was achieved in 62%, median DOR was 14.8 months (95% CI, 5.5 months to not reached), and median OS was 13.5 months (95% CI, 7.0 to 18.4 months).

CONCLUSION

Venetoclax plus LDAC has a manageable safety profile, producing rapid and durable remissions in older adults with AML ineligible for intensive chemotherapy. High remission rate and low early mortality combined with rapid and durable remission make venetoclax and LDAC an attractive and novel treatment for older adults not suitable for intensive chemotherapy.

Hypomethylating agents in relapsed and refractory AML: outcomes and their predictors in a large international patient cohort

Although hypomethylating agents (HMAs) are frequently used in the frontline treatment of older acute myeloid leukemia (AML) patients, little is known about their effectiveness in relapsed or primary treatment-refractory (RR)-AML. Using an international multicenter retrospective database, we studied the effectiveness of HMAs in RR-AML and evaluated for predictors of response and overall survival (OS). A total of 655 patients from 12 centers received azacitidine (57%) or decitabine (43%), including 290 refractory (44%) and 365 relapsed (56%) patients. Median age at diagnosis was 65 years. Best response to HMAs was complete remission (CR; 11%) or CR with incomplete count recovery (CRi; 5.3%). Additionally, 8.5% experienced hematologic improvement. Median OS was 6.7 months (95% confidence interval, 6.1-7.3). As expected, OS differed significantly by best response, with patients achieving CR and CRi having a median OS of 25.3 and 14.6 months, respectively. In multivariate analysis, the presence of ≤5% circulating blasts and a 10-day schedule of decitabine were associated with improved response rates, whereas the presence of >5% circulating blasts and >20% bone marrow blasts were associated with decreased OS. A significant subset of RR-AML patients (16%) achieved CR/CRi with HMAs and experienced a median OS of 21 months. Outside of a clinical trial, HMAs represent a reasonable therapeutic option for some patients with RR-AML.

[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.

[Study of the effects and mechanism of all-trans retinoic acid on leukemic cell line U937 cells with NPM1 mutation]

Objective: To investigate the effect and mechanism of all-trans retinoic acid (ATRA) on leukemic cell line U937 cells with NPM1 mutation. Methods: Human acute myeloid leukemia cell line U937 was explored, NPM1 mutated (A type) plasmids were transfected into U937 to form stable clones A1 and A2, which were identified by Western blot and Co-immunoprecipitation. The cell proliferation was measured by methylthiazolyl tetrazolium bromide (MTT) ; cell cycle and cell apoptosis were explored by flow cytometric; cell colony formation was measured by microscope count, the molecular pathways related to cell proliferation were measured by Western blot. Results: ①The cell proliferations of mutant A1 and A2 were inhibited significantly by 52.6% and 35.8% (P<0.05) , respectively under ATRA exposure. ②The percentages of G(0)/G(1) stage of mutant A1 and A2 increased by 20.1% and 35.8%, respectively under ATRA exposure. ③All the U937 leukemic cells were inhibited under ATRA exposure; the decreased percentages of vector, wild-type and mutant NPM1 cells were 32.7%, 57.9% and 90.9% respectively. ④p-ERK decreased obviously after ATRA exposure in NPM1 mutated leukemic cells. ⑤More mutant NPM1 cells inclined to apoptosis under the exposure of ATRA and cytotoxic drugs than cytotoxic drugs alone, meanwhile more cells apoptosis occurred when ATRA was administrated after cytotoxic drugs exposure. Conclusions: ATRA could inhibit cell proliferation and colony formation, blocked the cell cycle in the G(0)/G(1) stage accompanied by the significant reduction of p-ERK in U937 leukemic cells with NPM1 mutation. Besides, ATRA could synergize with drugs to suppress the leukemic cells survival more effectively when ATRA was administered after the cytotoxic drugs exposure in U937 leukemic cells with NPM1 mutation.

Treatment patterns and comparative analysis of non-intensive regimens in elderly acute myeloid leukemia patients-a real-world experience from India

Elderly patients with acute myeloid leukemia have a poor prognosis. Data from developing countries is sparse in the literature. In this retrospective study, 402 patients aged ≥ 60 years, diagnosed between Jan 2013 and Dec 2017, were analyzed for treatment patterns and survival. Median age of the whole cohort was 68 years (range 61-84). A total of 213 patients (53.3%) refused care; 188 patients (46.7%) received either BSC, LDAC, or HMA. Survival (in months) was 3.9, 6.4, and 1.2 with LDAC, HMA, and BSC, respectively. One-year survival was 17.2% and 6% with HMA and LDAC, respectively (P = 0.02). Overall response rate (ORR) did not differ between HMA and LDAC group (p = 0.12). HMA cohort had higher complete responses (20.6% vs 7.4%, p = 0.02), stable disease (32.7% vs 13.5%, p = 0.02), and transfusion independence (TI) (46.5% vs 22.2%, p = 0.01). Survival did not differ between the groups if the patients achieved ORR (12.3 vs 9.8 p = 0.2) or TI (11.6 vs 6.4 p = 0.2). Stable disease with HMA led to longer survival (8.1 vs 5.3 p = 0.01). HMAs were more effective than LDAC irrespective of cytogenetic risk category and blasts, of note HMAs improved survival of poor risk patients (5.6 vs 2.9 p = 0.004). HMA treatment (HR = 0.48; 95% 0.29-0.79, p = 0.004) and transfusion independence (HR = 0.2; 95% 0.1-0.3, p = 0.0001) predicted survival in multivariate analysis. Neutropenia and febrile neutropenia were frequent in HMA. Thrombocytopenia was the common adverse event with LDAC. Novel and cost-effective drugs are essential to improve the prognosis of these patients.

Randomized comparison of low dose cytarabine with or without glasdegib in patients with newly diagnosed acute myeloid leukemia or high-risk myelodysplastic syndrome

Glasdegib is a Hedgehog pathway inhibitor. This phase II, randomized, open-label, multicenter study (ClinicalTrials.gov, NCT01546038) evaluated the efficacy of glasdegib plus low-dose cytarabine (LDAC) in patients with acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome unsuitable for intensive chemotherapy. Glasdegib 100 mg (oral, QD) was administered continuously in 28-day cycles; LDAC 20 mg (subcutaneous, BID) was administered for 10 per 28 days. Patients (stratified by cytogenetic risk) were randomized (2:1) to receive glasdegib/LDAC or LDAC. The primary endpoint was overall survival. Eighty-eight and 44 patients were randomized to glasdegib/LDAC and LDAC, respectively. Median (80% confidence interval [CI]) overall survival was 8.8 (6.9–9.9) months with glasdegib/LDAC and 4.9 (3.5–6.0) months with LDAC (hazard ratio, 0.51; 80% CI, 0.39–0.67, P = 0.0004). Fifteen (17.0%) and 1 (2.3%) patients in the glasdegib/LDAC and LDAC arms, respectively, achieved complete remission (P < 0.05). Nonhematologic grade 3/4 all-causality adverse events included pneumonia (16.7%) and fatigue (14.3%) with glasdegib/LDAC and pneumonia (14.6%) with LDAC. Clinical efficacy was evident across patients with diverse mutational profiles. Glasdegib plus LDAC has a favorable benefit–risk profile and may be a promising option for AML patients unsuitable for intensive chemotherapy.

Myelodysplastic syndromes and acute myeloid leukemias in the elderly

Most patients above 60 years with acute myeloid leukemia (AML) will die from their disease. Nevertheless, the treatment concepts in elderly patients with myelodysplastic syndromes (MDS) and AML are rapidly evolving. A number of recent reports have identified better survival rates with intensive induction chemotherapy for patients up to 80 years, with the exception of patients with unfavorable genomic risk abnormalities or with major co-morbidities. Gemtuzumab ozogamicin is increasingly added to induction therapy for AML patients up to 70 years with favorable or intermediate risk profile, and Midostaurin for patients with a FLT3 mutation. The recommended dose of daunorubicin is 60 mg/m² for 3 + 7 induction therapy. Elderly patients with acute promyelocytic leukemia should receive all-trans retinoic acid and arsenic trioxide, and cytotoxic treatment is limited upfront to patients with initial leukocytosis. Allogeneic transplantation can be recommended to selected patients up to 70-75 years. For patients unfit for intensive treatment, therapeutic options comprise a hypomethylating agent (HMA), low-dose cytarabin and supportive care. HMA treatment is also increasingly applied for relapsed/refractory AML after intensive chemotherapy. A considerable number of candidate compounds are currently being studied in older AML patients, with their potential role in the treatment of elderly AML patients remaining to be clarified.

Acute myeloid leukemia in the elderly: what constitutes treatment value?

Treatment options for patients with acute myeloid leukemia (AML), who are unfit for induction chemotherapy are unsatisfactory. Overall survival (OS) superiority has not been demonstrated in randomized controlled trials (RCT) in this population, challenging the value of available therapies. We sought to assess the relative value of approved therapies using value-assessment tools. Clinical, safety, quality-of-life (QOL), supportive care, and resource utilization outcomes data were abstracted from RCTs and examined using value-assessment frameworks. Three RCTs, one each of azacitidine, decitabine, and low-dose cytarabine were identified. OS was not statistically significant and secondary outcomes including response rates, rates of transfusion independence, the frequency of hospitalizations and changes in QOL were reported differently across trials. Value-assessment tools considered OS as the primary efficacy endpoint without consideration to response rates. The NCCN Evidence Blocks^TM were most successful in considering secondary endpoints. With the move toward value-based care, understanding how these value tools apply to AML patients is critical.