Myelodysplasia

A randomized, double-blind, placebo-controlled phase 2 study evaluating the efficacy and safety of romiplostim treatment of patients with low or intermediate-1 risk myelodysplastic syndrome receiving lenalidomide

Background

Lenalidomide treatment in myelodysplastic syndrome (MDS) may lead to thrombocytopenia and dose reductions/delays. This study evaluated the safety and tolerability of the thrombopoietin mimetic romiplostim and its effects on the incidence of clinically significant thrombocytopenic events (CSTEs) in lower risk MDS patients receiving lenalidomide.

Methods

Patients were assigned to weekly placebo (n = 12) or romiplostim 500 μg (n = 14) or 750 μg (n = 13) for four 28-day lenalidomide cycles.

Results

The treatment groups were generally similar with respect to baseline disease characteristics. Del(5q) abnormalities were noted in 1 (8%) patient in the placebo group, 3 (21%) in the romiplostim 500 μg group, and two (15%) in the 750 μg group. CSTEs were noted in 8 (67%) patients in the placebo group, 4 (29%) in the romiplostim 500 μg group, and 8 (62%) in the romiplostim 750 μg group. Throughout the study, median platelet counts trended lower in placebo-treated than in romiplostim-treated patients. Thrombocytopenia-related adjustments in lenalidomide occurred in 6 (50%) patients in the placebo group, 5 (36%) in the romiplostim 500 μg group, and 2 (15%) in the 750 μg group. Although the percentages of patients who received platelet transfusions were similar across treatment groups, there was a trend toward lower numbers of transfusions in both romiplostim groups during each treatment cycle. There were two serious treatment-related adverse events during the treatment period (cerebrovascular accident, placebo; worsening thrombocytopenia, romiplostim 500 μg). Two patients (romiplostim 500 and 750 μg, respectively) had an increase in bone marrow blasts to >20% during treatment, but had no post-treatment biopsy to confirm or exclude the diagnosis of progression to AML.

Conclusions

These data suggest that romiplostim administered to MDS patients during lenalidomide treatment may decrease the frequency of dose reductions/delays due to thrombocytopenia. Additional study is needed to confirm the results of this preliminary trial.

Trial registration

ClinicalTrials.gov NCT00418665

Health care utilization and mortality among elderly patients with myelodysplastic syndromes

BACKGROUND

Mortality in patients with myelodysplastic syndromes (MDS) is high, and patients are likely to require hospitalizations, emergency department (ED) visits, and transfusions. The relationships between these events and the MDS complications of anemia, neutropenia, and thrombocytopenia are not well understood.

PATIENTS AND METHODS

A total of 1864 patients registered in the United States' Surveillance Epidemiology and End Results (SEER) program and aged ≥ 66 years old when diagnosed with MDS in 2001 or 2002 were included. Medicare claims were used to identify MDS complications and utilization (hospitalizations, ED visits, and transfusions) until death or the end of 2005. Mortality was based on SEER data. Kaplan-Meier incidence rates were estimated and multivariable Cox models were used to study the association between complications and outcomes.

RESULTS

The 3-year incidence of anemia, neutropenia, and thrombocytopenia was 81%, 25%, and 41%, and the incidence of hospitalization, ED visit, and transfusion was 62%, 42%, and 45%, respectively. Median survival time was 22 months. Cytopenia complications were significantly associated with each of these outcomes.

CONCLUSIONS

All types of cytopenia are common among patients with MDS and are risk factors for high rates of health care utilization and mortality. Management of the complications of MDS may improve patient outcomes.

Review of stem-cell transplantation for myelodysplastic syndromes in older patients in the context of the Decision Memo for Allogeneic Hematopoietic Stem Cell Transplantation for Myelodysplastic Syndrome emanating from the Centers for Medicare and Medicaid Services

Myelodysplastic syndromes (MDS) comprise a heterogeneous group of clonal hematopoietic stem-cell disorders that result in varying degrees of cytopenia and risk of transformation into acute leukemia. Allogeneic stem-cell transplantation (SCT) is the only known cure for this disease. The treatment is routinely used for younger patients, but only a minority of patients older than the age of 60 undergo this procedure. The overall MDS incidence is 3.3 per 100,000, but the incidence in patients older than age 70 is between 15 and 50 per 100,000. The median age at presentation is 76 years. Medicare-age patients 65 or older represent 80% of the total population receiving an MDS diagnosis. In the United States, one of the obstacles to SCT for older patients with MDS has been lack of third party reimbursement. On August 4, 2010, the Centers for Medicare and Medicaid Services released their Decision Memo for Allogeneic Hematopoietic Stem Cell Transplantation (HSCT) for Myelodysplastic Syndrome. This memo states: "Allogeneic HSCT for MDS is covered by Medicare only for beneficiaries with MDS participating in an approved clinical study that meets the criteria below…. " In this review, we will summarize what is known regarding the role of allogeneic SCT in older patients as well as other elements that should be included within clinical trials that can provide the evidence necessary to demonstrate that allogeneic SCT should be a covered benefit for Medicare beneficiaries.

Safety and efficacy of romiplostim in patients with lower-risk myelodysplastic syndrome and thrombocytopenia

PURPOSE

To assess the safety and efficacy of romiplostim, a peptibody that increases platelet production, for treatment of thrombocytopenic patients with myelodysplastic syndromes (MDS).

PATIENTS AND METHODS

Eligible patients had lower-risk MDS (International Prognostic Scoring System low or intermediate 1), a mean baseline platelet count <or= 50 x 10(9)/L, and were only receiving supportive care. Patients received three injections of 300, 700, 1,000, or 1,500 microg romiplostim at weekly intervals. After evaluation of platelet response at week 4, patients could continue to receive romiplostim in a treatment extension phase for up to 1 year.

RESULTS

All 44 patients who enrolled completed the treatment phase; 41 patients continued into the extension phase. Median platelet counts increased throughout the study, from fewer than 30 x 10(9)/L at baseline to 60, 73, 38, and 58 x 10(9)/L at week 4 for the 300-, 700-, 1,000-, and 1,500 -microg dose cohorts, respectively. A durable platelet response (per International Working Group 2000 criteria for 8 consecutive weeks independent of platelet transfusions) was achieved by 19 patients (46%). The incidence of bleeding events and platelet transfusions was less common among patients who achieved a durable platelet response than those who did not (4.3 v 39.3 per 100 patient-weeks). Forty-three patients (98%) reported one or more adverse events. Treatment-related serious adverse events were reported in five patients (11%), all of whom were in the 1,500-microg dose cohort. Two patients progressed to acute myeloid leukemia during the study. No neutralizing antibodies to either romiplostim or endogenous thrombopoietin were seen.

CONCLUSION

Romiplostim appeared well-tolerated in this study and may be a useful treatment for patients with MDS and thrombocytopenia.

Azacitidine: a novel agent for myelodysplastic syndromes

PURPOSE

The pharmacology, pharmacokinetics, clinical efficacy, dosage and administration, and safety of azacitidine are reviewed.

SUMMARY

Azacitidine is the first drug in a new class of compounds, known as DNA hypomethylating agents, to receive FDA-approved labeling for the treatment of myelodysplastic syndromes. It exerts its antineoplastic activity by causing a direct cytotoxic effect on abnormally proliferating hematopoietic cell lines by interfering with nucleic acid metabolism. Azacitidine is rapidly absorbed following subcutaneous injection, with peak plasma concentrations achieved within 30 minutes of administration. Based on promising results in Phase I-II testing, azacitidine entered Phase III testing in all subtypes of myelodysplastic syndromes. Azacitidine was compared with best supportive care, the previous standard therapy for myelodysplastic syndromes, demonstrating improvements in hematologic response, delaying time to progression to acute myelogenous leukemia, and increasing overall survival. Azacitidine is available as sterile lyophilized powder in single-use vials for reconstitution. The recommended dosage of azacitidine for the first treatment cycle is 75 mg/m(2) daily for seven days. The treatment cycle should be repeated every four weeks for a minimum of four cycles. Overall, azacitidine appears to be well tolerated, with the most common adverse effects being myelosuppression, nausea, and vomiting.

CONCLUSION

Azacitidine is the first DNA hypomethylating agent approved by FDA for the treatment of myelodysplastic syndromes and has demonstrated superior efficacy and improvements in patients' quality of life and bone marrow function over supportive care.

Decitabine in Myelodysplastic Syndromes

Myelodysplastic syndromes (MDS) are a heterogenous group of hematopoietic stem cell disorders that are multifactorial in their etiology. Aberrant DNA hypermethylation is now thought to be involved in MDS, as numerous tumor-suppressor genes have been identified that are silenced in these patients. Thus, the use of DNA methyltransferase inhibitors, such as 5-aza-2'-deoxycytidine (decitabine, Dacogen, MGI Pharma Inc, Bloomington, MN), for reversal of this process appears to be a rational intervention that may influence the course of the disease. Several phase I/II studies have been conducted using a low-dose schedule of decitabine in MDS patients. Based on these studies, decitabine appears to be effective and generally well tolerated, especially in those patients with worse prognostic indicators. Recent results of a phase III study also confirmed that patients treated with decitabine compared to standard supportive care had higher overall response rates and longer time to AML transformation. Decitabine appears to be a promising new therapy for the treatment of MDS; however, defining the optimal dosing schedule and exploring the possible use in combination with other agents such as the histone deacetylase inhibitors need further evaluation.

Management of patients receiving antithymocyte globulin for aplastic anemia and myelodysplastic syndrome

Antithymocyte globulin (ATG) is used commonly in patients with severe aplastic anemia and those undergoing renal transplant. Its utility also is being explored in the treatment of myelodysplastic syndrome, conditioning regimens for hematopoietic stem cell transplant, and prophylaxis of graft-versus-host disease. As indications for ATG expand, knowledge regarding its administration and management of associated toxicities is needed. These toxicities range from life-threatening anaphylaxis associated with the infusion to flu-like symptoms that occur one to two weeks after the infusion. Adverse effects are classified according to the severity and system impacted. Mild toxicities respond to comfort measures and include fever, chills, urticarial rash, and vomiting. Moderate toxicities require acute interventions and include fluid-responsive hypotension, nonischemic chest pain, and reversible oxygen desaturation. Severe toxicities require intensive support and include those refractory to earlier intervention. Management of these toxicities usually is limited to fluid resuscitation and noninvasive monitoring. Occurrence of infusion-related toxicities may require premature discontinuation of therapy. Therefore, an educated healthcare team and interdisciplinary clinical management guidelines are important to ensure the safe administration and complete course of ATG.

Myelodysplasia and Radiation

Reasons are given why myelodysplasia should be considered in any assessment in humans of radiation exposure as an etiological factor for the development of leukemia.

Bilateral renal infarction in chronic myelomonocytic leukemia on blast crisis

The major complications of myelodysplastic syndromes are related to cytopenia and evolution to acute myeloid leukemia. Bleeding episodes in MDS, although relatively uncommon, are often related to thrombocytopenia. Bleeding may be exacerbated by platelet dysfunction, which is also found frequently. Furthermore, the major hemostatic problem underlying hyperleukocytosis, as evident in patients with MDS on blast crisis, appears to be hemorrhage rather than thrombosis. Acute thromboembolism, which causes occlusion of blood supply and organ infarction, has rarely been observed in patients with MDS. Recently, we encountered an elderly female patient, who had chronic myelomonocytic leukemia with marked myelodysplasia, terminating in blast crisis and bilateral renal infarction. This complication rapidly led to oliguric acute renal failure and mortality.

New insights into the physiology and treatment of acquired myelodysplastic syndromes and aplastic pancytopenia

MDS are a diverse group of primary and secondary bone marrow disorders that are characterized by cytopenias in blood, prominent dysplastic features in blood or bone marrow, and normal or hypercellular bone marrow. MDS in cats are typically associated with FeLV infection. Dogs with MDS-RC and MDS-Er seem to respond to erythropoietin administration and have prolonged survival. Dogs with MDS-EB respond poorly to present treatments, and survival is short. Prognosis and probability of progression to acute myelogenous leukemia can be predicted based on the percentage of myeloblasts in bone marrow. Several experimental therapeutic modalities in human beings have been described that may be useful in treating MDS-EB in dogs and cats. Aplastic pancytopenia is a relatively rare disorder in dogs and cats. Causes include Ehrlichia spp, Parvovirus, and FeLV infections; sepsis; chronic renal failure; drug and toxin exposure; and idiopathic causes. Diagnosis is based on identification of multiple cytopenias in the blood and hypoplastic/aplastic bone marrow, with the marrow space replaced by adipose tissue. Treatment and outcome are dependent on determining the underlying cause of the bone marrow failure.

Apoptotic rate in patients with myelodisplastic syndrome treated with modulatory compounds of pro-apoptotic cytokines

Excessive apoptosis has a central role in ineffective hematopoiesis in myelodysplastic syndrome (MDS). The aim of the study was to quantify apoptosis and Bcl-2 expression in patients with MDS and to use these parameters in the evaluation of treatment efficacy with compounds modulating proapoptotic cytokines. Bone marrow (BM) samples from eight MDS patients were studied: four with refractory anemia and four with refractory anemia with ringed sideroblasts. Two patients with Hodgkin disease without BM determination were studied for control. Therapy consisted in administration of pentoxyphylline, dexamethasone and ciprofloxacin. Biochemical assay of apoptosis and Bcl-2 was performed using annexin V-biotin conjugate antibody and anti-human Bcl-2 antibody respectively, followed by streptavidine-peroxidase conjugate, and peroxidase substrate. Ultrastructural investigation of BM samples was performed with standard electron microscopy techniques. Most of BM hematopoietic cells in the MDS patients had ultrastructural features of various stages of apoptosis including chromatin condensation and margination, cytoplasm condensation and budding of nuclear and plasma membranes to produce apoptotic bodies. Bcl-2 expression showed an inverse correlation with the rate of the apoptotic process. Periodic evaluation of these two parameters has shown an increase of Bcl-2 expression and a decrease of apoptotic rate in patients who had responded to the treatment. Response to the treatment was appreciated in accordance with their transfusion needs. Treatment efficiency diminished in time. The rate of apoptosis was inversely correlated with the level of Bcl-2 expression. These results confirm the importance of the apoptotic process evaluation in monitoring MDS treatment.

Mitochondrial DNA mutations in patients with myelodysplastic syndromes

We undertook to systematically analyze the entire mitochondrial genome by gene amplification and direct sequencing in 10 patients with myelodysplasia; results were compared with concomitantly studied 8 healthy volunteers as well as mtDNA sequences in a standard database. Nucleotide changes that were present in our healthy controls as well as those in published databases were counted as polymorphisms. Overall, there was no increase in the number of mtDNA genes harboring polymorphisms or "new" mutations between our patients and healthy controls, although there were a few more mtDNA changes resulting in amino acid changes in myelodysplasia (9 in 8 controls versus 16 in 10 patients). Thirty new mutations, all nucleotide substitutions, were found among the 10 patients, distributed throughout the mitochondrial genome; 5 mutations resulted in amino acid changes. None of the mutations in controls produced amino acid changes. We were not able to confirm previously described mutations in sideroblastic anemia or "hot spots" in the cytochrome c oxidase I and II genes. Our data do not support a major role for mitochondrial genomic instability in myelodysplasia, and they fail to reproduce previous reports of significant or widespread mitochondrial mutations in this disease. Modest changes in mutation numbers and mitochondrial microsatellites may be evidence of increased mutagenesis in mtDNA, or, more likely, a reflection of limited clonality among hematopoietic stem cells in this bone marrow failure syndrome.

New approaches to the treatment of myelodysplasia

The therapeutic dilemma that confronts the management of patients with myelodysplastic syndromes (MDS) is illustrated by the absence of a Food and Drug Administration-approved agent with an indication for this disease. Clinical heterogeneity and inadequate understanding of the disease pathobiology have limited progress in the development of novel therapeutics. Preclinical investigations indicate that reciprocal interaction between the malignant clone and the microenvironment serve to create a hostile milieu that reinforces ineffective blood cell production. Ineffective hematopoiesis, the hallmark of MDS, arises from impaired progenitor responsiveness to normal trophic signals and excess local generation of inhibitory cytokines, which promote accelerated apoptotic loss of progenitors and their progeny. Evidence to support this model derives from cytokine neutralization studies and the direct relationship between plasma tumor necrosis factor-alpha concentration and DNA oxidation and glutathione depletion in malignant CD34+ progenitors. Recent investigations indicate that angiogenic molecules generated by malignant myelomonocytic precursors represent integral diffusable signals that reinforce leukemia progenitor self-renewal while promoting the generation of proapoptotic cytokines and medullary angiogenic response. The potential for leukemia evolution is compounded by epigenetic events including methylation silencing of the p15 proto-oncogene or activating ras point mutations. Delineation of such biologic features that are central to the pathobiology of MDS provides a reliable framework for the development of novel therapeutics. Antiangiogenic agents in clinical testing include vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitors, thalidomide and related analogues, and the recombinant VEGF neutralizing antibody, bevacizumab. Agents whose actions may restore differentiation programs, such as the DNA methyltransferase inhibitors or histone deacetylase inhibitors, offer the prospect to promote effective hematopoiesis while impacting the potential for leukemia evolution. RAS farnesyl transferase inhibitors have shown encouraging preliminary results in acute myeloid leukemia and are currently under investigation in advanced MDS and chronic myelomonocytic leukemia. Arsenic trioxide (ATO) interacts with a spectrum of biologic targets that may be uniquely suited to MDS. ATO is a potent inducer of apoptosis in thiol-depleted malignant progenitors and neovascular endothelium, while promoting differentiation through histone acetylation and inactivation of transcriptional corepressors. The identification of relevant biologic targets in MDS has raised expectations for the development of disease-specific therapies for MDS in the years that follow.

Targeting hypomethylation of DNA to achieve cellular differentiation in myelodysplastic syndromes (MDS)

Considerable progress has been made recently in defining and understanding the diverse members of the group of hematologic disorders now known as the myelodysplastic syndrome (MDS). New systems of classification, based on the latest cytogenetic methodologies, have generated better prognostic data, and basic research has more closely associated molecular mechanisms with clinical subgroups. The mechanisms underlying most cases of myelodysplasia appear to be an array of chromosomal abnormalities leading to suppression of normal myeloid cell differentiation and dominance of abnormal, immature cells. The process is progressive and is mediated by a variety of cytokines, potential loss of tumor suppressor genes, aberrations in signal transduction pathways, and perhaps immune mechanisms. Hypermethylation of specific DNA sequences has been implicated in the pathogenesis of MDS. Until recently, treatment options have been few, high risk, and mostly ineffective. New discoveries, particularly in the area of stimulating remaining normal myeloid cells to resume growth and differentiation, hold promise for safer treatment regimens and improved outcomes. Among the promising new agents are nucleoside analogues, such as 5-azacytidine and decitabine, which reactivate tumor suppressor gene transcription through effects on DNA methylation.

Primary myelodysplasia: management and outcome at 3 years in 45 patients age 65 and older

OBJECTIVES

To study myelodysplasia in patients age 65 and older.

SETTING

A French university hospital.

PARTICIPANTS

Forty-five patients age 65 and older with a diagnosis of myelodysplasia made in the hospital between January 1993 and December 1998.

MEASUREMENTS

Clinical presentation, initial hematological features, type of myelodysplasia (French American British classification), treatment, and evolution at 36 months were studied.

RESULTS

The mean age of the group was 78. Anemia was the initial hematological feature in 30 patients out of 45 and was symptomatic in 24 patients. Refractory anemia was diagnosed in 20 patients; 11 patients presented with refractory anemia with excess blast cells, eight with chronic myelomonocytic leukemia. Thirty-one patients received erythrocyte transfusions, no patient received chemotherapy. At 36 months, 68.8% of the patients were dead. The median survival (22 months) was lower than in other reported series even in types of myelodysplasia with a classically better prognosis.

CONCLUSION

Myelodysplasia is probably underdiagnosed in older people and has a poor prognosis (median survival 22 months), and no effective treatment is available in older patients.

Treatment of patients with myelodysplastic syndrome with amifostine

The efficacy and toxicity of amifostine (300 mg/m(2) three times a week for three consecutive weeks for a maximum of six courses) was evaluated in 12 patients with primary myelodysplastic syndromes. Dose escalation up to 400 mg/m(2) was allowed to patients who failed to respond. Hemoglobin concentration was increased > or = 1.5 g/dl in two (18%) of the 11 anemic patients. These two patients obtained transfusion independence for 20 weeks. Reticulocyte counts and ANC increased > or = 50% of baseline in four (44%) of the nine patients with reticulocytopenia and in three (25%) of the 12 neutropenic patients. Platelet count increased in three (50%) of the six patients with thrombocytopenia. Progenitor growth of CFU-GMs and BFU-Es improved in 8/12 patients. No major side effects were observed. In conclusion amifostine is well tolerated and can promote the growth of primitive hematopoietic progenitors and ameliorate the cytopenias in MDS patients.