Once-weekly dosing of recombinant human erythropoietin alpha in patients with myelodysplastic syndromes unresponsive to conventional dosing

A Systematic Literature Review of Predictors of Erythropoiesis-Stimulating Agent Failure in Lower-Risk Myelodysplastic Syndromes

Erythropoiesis-stimulating agents (ESAs) are the first-line treatment option for anemia in patients with lower-risk myelodysplastic syndromes (LR-MDS). A systematic literature review was conducted to identify evidence of the association between prognostic factors and ESA response/failure in LR-MDS. MEDLINE, Embase, and relevant conferences were searched systematically for studies assessing the association between prognostic factors and ESA response/failure in adult patients. Of 1566 citations identified, 38 were included. Patient risk status in studies published from 2000 onwards was commonly assessed using the International Prognostic Scoring System (IPSS) or revised IPSS. ESA response was generally assessed using the International Working Group MDS criteria. Among the included studies, statistically significant relationships were found, in both univariate and multivariate analyses, between ESA response and the following prognostic factors: higher hemoglobin levels, lower serum erythropoietin levels, and transfusion independence. Furthermore, other prognostic factors such as age, bone marrow blasts, serum ferritin level, IPSS risk status, and karyotype status did not demonstrate statistically significant relationships with ESA response. This systematic literature review has confirmed prognostic factors of ESA response/failure. Guidance to correctly identify patients with these characteristics could be helpful for clinicians to provide optimal treatment.

Response Assessment to Erythropoietin-Zeta (Epo-Alpha Biosimilar) Therapy in Low-Risk Myelodysplastic Syndromes

Background. This prospective observational study aimed to verify the efficacy of erythropoietin zeta in the treatment of patients with low-risk myelodysplastic syndrome. Methods. Patients with low/int-1 IPSS risk and serum erythropoietin level below 500 U/L were enrolled. Treatment consisted of erythropoietin zeta 40,000 U subcutaneously once a week. The primary endpoint was the erythroid response. According to Simon’s two-stage statistical design, 36 patients were recruited. The median age was 75 years (range 56–83 years), male/female ratio was 1.1/1, median baseline serum erythropoietin was 57.9 U/L (range 9.4–475 U/L). 53% of patients had low-risk disease, while the remaining had Int-1 risk. Results. After 8 weeks, a significant response (rise in Hb levels of at least 1.5 g/dL) was achieved in 18 patients (50%) out of 36. However, 17 patients did not improve; 8/17 patients pursued the 40,000 U weekly schedule of erythropoietin zeta, and 4/8 (50%) of them reached the erythroid response after 16 weeks. Nine patients underwent dosage doubling (40,000 U twice per week), and 5/9 (55%) of them achieved the erythroid response. Conclusion. Compared with data from the literature, this prospective study revealed that EPO-zeta is a safe and effective therapeutic option in low-risk MDS patients.

Biosimilar epoetin α is as effective as originator epoetin-α plus liposomal iron (Sideral®), vitamin B12 and folates in patients with refractory anemia: A retrospective real-life approach

Several biosimilar versions of recombinant human erythropoietin are currently approved for use in Europe, including a biosimilar epoetin-α. The aim of this the study was to verify that biosimilar epoetin-α is similar in terms of efficacy, safety and cost to originator epoetin-α for the treatment of refractory anemia in patients with myelodysplastic syndrome. A total of 92 patients with myelodysplasia and refractory anemia were investigated. The patients received either originator (group A) or biosimilar (group B) epoetin-α. In addition, they received liposomal iron (Sideral®), calcium levofolinate and vitamin B12. Moreover, the median monthly overall costs were calculated for each group. The results demonstrated that hemoglobin (Hb) levels increased by 1 g/dl after a median time of 5 weeks in group A and 4 weeks in group B. In group A, a Hb level of >12 g/dl was achieved after 12 weeks, while in group B after 10.5 weeks. The median cost of therapy was 1,536 euros/month in group A and 1,354 euros/month in group B. A total of 5 patients required transfusion support in group A and 7 in group B. In conclusion, biosimilar epoetin-α appears to be comparable to originator epoetin-α in terms of efficacy and safety for the treatment of refractory anemia.

Myelodysplastic syndromes: toward a risk-adapted treatment approach

Several classification and scoring systems have been developed in myelodysplastic syndromes (MDS to predict the risk of progression to acute myeloid leukemia and survival. These prognostication models have been also used to inform therapeutic decision-making in a risk-adapted fashion. Patient-related factors such as age, comorbidities, and functional status have to be considered as well. Here we review a risk-guided therapeutic approach for the management of MDS patients. It is anticipated that the improved understanding of the complex pathogenesis of MDS and the recent discovery of important molecular lesions will be translated into novel therapeutic approaches. Additionally, some prognostic aberrations are expected to be incorporated into the prognostic tools with the goal of improving their prognostic precision and therefore allow for a more informed therapeutic decision-making based on the individual's risk profile.

Treatment of low-risk myelodysplastic syndrome: hematopoietic growth factors erythropoietins and thrombopoietins

The use of erythropoietic growth factors has become standard of care in many countries for lower risk myelodysplastic syndrome (MDS) patients. Throughout a large number of clinical trials, therapy with erythropoietic agents has consistently shown improvement of anemia and reduction of transfusion dependence. There is currently no evidence of safety issues of erythropoietins in MDS, including thrombosis, polycythemia, and progressive disease. Large retrospective comparative analyses have shown no increase in mortality in erythropoietin (EPO)-treated MDS patients. Doses of up to 80,000 IU/wk have successfully been employed and the addition of granulocyte colony-stimulating factor (G-CSF) can benefit previously unresponsive patients. Although several other combination therapies have been tested, apart from G-CSF, none has gained wide clinical acceptance. Thrombopoietic agents can alleviate thrombocytopenia and bleeding symptoms in lower risk MDS patients. However, concerns regarding a higher rate of transformation to acute myeloid leukemia and the fear of increased bone marrow fibrosis during treatment have hampered their clinical development.

High-dose (40,000 IU twice/week) alpha recombinant human erythropoietin as single agent in low/intermediate risk myelodysplastic syndromes: a retrospective investigation on 133 patients treated in a single institution

We investigated the efficacy of alpha recombinant human erythropoietin (α-rHuEPO) administered as single agent to 133 patients affected by myelodysplastic syndromes referring to our Institution in the last 10 years. WPSS score was "very low" in 67%, "low" in 19%, "intermediate" in 14%. The starting schedule was: 40,000 IU bi-weekly, with reduction or suspension, when necessary, in responsive patients. According to new IWG criteria, response rate (RR) was 75%, 66%, 59% after 8, 16, 24 weeks, respectively. Comparing "very low" and "low/intermediate" risk, RR was 81% vs. 43% (P < 0.001); 70% vs. 45% (P = 0.040); 63% vs. 42% (P = NS) after 8, 16, 24 weeks. RR was significantly influenced by transfusion dependence (P = 0.039) and basal serum EPO level (P < 0.001). Mean Hb value was 94 ± 11 g/l before therapy; 114 ± 19 after 8 weeks (P < 0.001); 116 ± 18 after 16 weeks (P < 0.001); 114 ± 17 after 24 weeks (P < 0.001). Reduction or suspension of therapy significantly affected Hb level after 4 (P < 0.001) and 8 weeks (P < 0.01). Conversely, restart of full dosage significantly enhanced again Hb level after 4 (P < 0.01) and 8 weeks (P < 0.001). 65% patients are alive (mean survival: 74 weeks). Seventy percent are alive in the "very low risk" group and 38% in "low/intermediate risk" group (P < 0.001). Overall mean follow-up was 69 weeks (range, 8-376): it was 80 weeks in responsive patients (max 376) and 38 weeks in patients who progressively became unresponsive (max 168) (P < 0.01). Median response was 36 weeks, with 33% of patients still responding after one year. Treatment was well tolerated.

Phase 1 multicenter dose-escalation study of ezatiostat hydrochloride (TLK199 tablets), a novel glutathione analog prodrug, in patients with myelodysplastic syndrome

Phase 1 testing of ezatiostat, a glutathione S-transferase P1-1 inhibitor, for the treatment of myelodysplastic syndrome was conducted in a multidose-escalation study. Patients received 10 dose levels (200, 400, 1000, 1400, 2000, 2400, 3000, 4000, 5000, and 6000 mg) of ezatiostat tablets in divided doses on days 1 to 7 of a 21-day cycle for a maximum of 8 cycles. The safety and pharmacokinetics of ezatiostat were evaluated. Forty-five patients with low to intermediate-2 International Prognostic Scoring System risk myelodysplastic syndrome were enrolled. No dose-limiting toxicities were observed. The most common grade 1 or 2, respectively, treatment-related adverse events were nonhematologic: nausea (56%, 9%), diarrhea (36%, 7%), vomiting (24%, 7%), abdominal pain (9%, 0%), constipation (4%, 9%), anorexia (3%, 7%), and dyspepsia (3%, 7%). Concentration of the primary active metabolite, TLK236, increased proportionate to ezatiostat dosage. Seventeen hematologic improvement (HI) responses by International Working Group criteria were observed at dose levels of 200 to 6000 mg/day with 11 HI responses at doses of 4000 to 6000 mg/day. HI responses occurred in all lineages including 3 bilineage and 1 complete cytogenetic response. Decreased number of red blood cell and platelet transfusions and in some cases transfusion independence were attained. Extended dose schedules of ezatiostat tablets are under investigation. This study was registered at http://www.clinicaltrials.gov as NCT00280631.

Efficacy of a combination of human recombinant erythropoietin + 13-cis-retinoic acid and dihydroxylated vitamin D3 to improve moderate to severe anaemia in low/intermediate risk myelodysplastic syndromes

The efficacy of human recombinant erythropoietin (rEPO) in myelodysplastic syndromes (MDS) has generally been best in untransfused patients with 'refractory anaemia' according to the World Health Organization (WHO). We treated 63 MDS patients [excluding refractory anaemia with excess blasts, type 2 (RAEB2)] with a previously tested combination of 13-cis-retinoic acid and dihydroxylated vitamin D3 +/- 6-thioguanine in addition to rEPO. Most patients were categorized as refractory cytopenia with multilineage dysplasia and RAEB1, with intermediate 1 International Prognostic Scoring System (IPSS) score; all had Hb <95 g/l, and 70% required regular erythrocyte transfusions. Treatment was well tolerated, and erythroid response rate according to new International Working Group criteria was 60%: 50% in RAEB1 and 64% in non-RAEB patients (P = 0.383). Response rate was not affected by transfusion requirement (63%; 58% in untransfused), IPSS and WHO Prognostic Scoring System scores, and weekly rEPO dosage (30-50 000 U vs. 80 000 U). Median response duration was 16 months. Median survival reached 14 months for RAEB1 and 55 months for non-RAEB patients, with a significant difference in the latter between responders and non-responders (median 82 months vs. 44 months; P = 0.036). Our combined therapy, independent of rEPO dosage, achieved in patients with unfavourable response predictors, a rate of anaemia improvement comparable to the best obtained in lower risk patients by high-dose rEPO.

The role of rHuEpo in low-risk myelodysplastic syndrome patients

Myelodysplastic syndromes (MDS) are clonal disorders of the haemopoietic stem cell characterized by peripheral cytopenias that are the result of abnormal haemopoietic differentiation and maturation. Approximately 90% of MDS patients present with anemia at the beginning or during the course of the disease and often require transfusions. The rationale for treating anemic MDS patients with recombinant human erythropoietin (rHuEpo), alone or in combination with other growth factors, is based on the possibility of overcoming the defective proliferation and maturation of erythroid precursors through the inhibition of bone marrow apoptosis, the enhancement of the differentiation of preleukemic progenitor cells or the stimulation of the growth of residual normal haematopoietic cells. Clinical trails have shown that rHuEpo, alone or in combination with recombinant human granulocyte colony-stimulating factor, is a useful drug for the treatment of anemia in low-risk MDS patients, and the same trials have identified patients who are more likely to respond to maximize benefits, to minimize adverse effects, and to avoid misuse or abuse. However, further research is required to determine whether this treatment has any real impact on quality of life and on life expectancy, thus allowing recommendations to be made about rHuEpo use in MDS patients with a degree of certainty.

Hematopoietic Growth Factors in the Treatment of Acquired Bone Marrow Failure States

In severe aplastic anemia (SAA), the use of hematopoietic growth factors (HGFs) to support blood counts is of limited value, as predicted by in vitro studies and measurement of endogenous serum levels of hematopoietic growth factors (HGF), which are markedly elevated. Benefit is usually only seen in those with less severe disease who are unlikely to require HGFs in practice. HGFs administered alone play no role in the treatment of SAA. The main indication for using HGFs, most often granulocyte colony-stimulating factor (G-CSF), in SAA has been to determine whether they increase the response rate to immunosuppressive therapy (IST) and improve survival. While earlier neutrophil recovery occurs when G-CSF is administered with IST, studies to date show no significant advantage in hematologic response or overall survival. Conflicting results have been reported concerning whether G-CSF increases the known risk of myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML) after IST; follow-up of at least 10 years is required, lacking in many clinical studies reported to date. In MDS, HGFs have been used to counteract the intramedullary apoptosis, which leads to ineffective hematopoiesis. In several uncontrolled and controlled studies, especially in low-risk MDS, high-dose erythropoietin (EPO) or its glycosylated derivative darbepoetin (DPO), alone or in combination with G-CSF, increased hemoglobin levels and diminished the need for red blood cell transfusions, in selected patients with prior transfusion frequency of less than 2 units per month and EPO levels below 500 IU/L. Quality-of-life measures were claimed to have improved, but the cost-effectiveness of this approach is debated, as is safety with regard to the risk of progression. G-CSF is used in supportive care of MDS to improve neutropenia during infectious complications, but to date there is no compelling evidence for a survival benefit or alteration of the course of the disease through the use of HGFs in MDS.

Advances in erythropoietic growth factor therapy for myelodysplastic syndromes

Refractory anaemia associated with excessive intramedullary erythroid apoptosis and dysplasia is a major feature of myelodysplastic syndromes (MDS). Recombinant human erythropoietin (specifically, epoetin alfa [EPO]) has been used in the therapy of MDS for many years. Initially, the erythroid response rates were modest, as EPO was used in all subgroups of MDS patients without discretion. However, with increased sophistication in patient selection and response evaluation criteria, there has been a significant improvement in the response rates to EPO therapy. This review discusses the evolution of therapeutic strategies incorporating EPO for the treatment of MDS.

Advances in the management of low- to intermediate-risk myelodysplastic syndrome: Integrating the National Comprehensive Cancer Network guidelines

Myelodysplastic syndromes (MDSs) are a group of hematologic diseases that present unique challenges for oncology nurses, especially because patients with the disorders are being seen more often in oncology practices. An increasing array of therapeutic options are available, and the National Comprehensive Cancer Network published its first clinical practice guidelines for MDSs in 2004. This article provides oncology nurses with the most recent data on supportive care as well as emerging therapies for patients with low- to intermediate-risk MDS.

Darbepoetin alfa for the treatment of anemic patients with low- and intermediate-1-risk myelodysplastic syndromes

BACKGROUND

The hematological and quality of life (QoL) changes associated with darbepoetin alfa (DA) therapy were assessed in anemic patients with previously untreated low- and intermediate-1-risk myelodysplastic syndrome (MDS).

PATIENTS AND METHODS

Fifty-three patients received DA administered subcutaneously once a week for 24 weeks. Treatment was initiated at 150 microg fixed dose and was doubled if after the first 12 weeks there was no or suboptimal erythroid response.

RESULTS

The final response rate was 24/53 (45%), with 21 major and three minor responses. Most of the responses (21/24; 87.5%) were obtained at the dose of 150 microg. With a median follow-up of 9.4 months, 17 patients maintain their response. Treatment was well tolerated with no relevant side-effects. MDS progression was observed in one case. Increases in hemoglobin levels were positively correlated with improved QoL scores using both the linear analog scale assessment (energy level, r = 0.429, P = 0.036; daily activities, r = 0.653, P < 0.001; overall well-being, r = 0.457, P = 0.024) and the Functional Assessment of Cancer Therapy-Anemia questionnaire (r = 0.247, P = 0.025). In multivariate analysis, only low levels (<200 IU/l) of endogenous erythropoietin predicted response to DA therapy.

CONCLUSIONS

DA is an active, safe and well tolerated treatment for anemia in a substantial proportion of patients with low- and intermediate-1-risk MDS, and has a positive impact on the patients' QoL.

Emerging drugs for the treatment of myelodysplastic syndrome

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal haematopoietic stem cell disorders characterised by ineffective haematopoiesis and an increased risk of developing acute myeloid leukaemia. At present, the only curative option is allogeneic stem cell transplantation. However, the majority of patients are not eligible for this therapy, due to excessive treatment-related morbidity and mortality or lack of a suitable donor. As a result, the need for alternative therapies is great. Our improved understanding of the molecular pathogenesis of MDS has resulted in several new promising therapeutic agents. This review will consider the rational development of new agents based on the molecular biology of MDS.