High doses of intravenous recombinant erythropoietin for the treatment of anaemia in myelodysplastic syndrome

A randomized comparison of once weekly epoetin alfa to extended schedule epoetin or darbepoetin in chemotherapy-associated anemia

Erythropoiesis-stimulating agents (ESAs) epoetin alfa (EA) and darbepoetin alfa (DA) increase hemoglobin (Hb) levels and reduce red blood cell (RBC) transfusion requirements in patients with cancer chemotherapy-associated anemia (CAA). Extended-interval ESA dosing (administration less than once weekly) is common with DA, but previous studies suggested that EA might also be administered less often than weekly. In this multicenter prospective trial, 239 CAA patients with Hb <10.5 g/dL were randomized to receive EA 40,000 U subcutaneously once weekly ("40K" arm), EA 80,000 U every 3 weeks ("80K"), EA 120,000 U every 3 weeks ("120K" arm), or DA 500 mcg every 3 weeks ("DA"), for 15 weeks. The primary endpoint was the proportion of patients achieving Hb ≥ 11.5 g/dL or increment of Hb > 2.0 g/dL from baseline without transfusion. Secondary endpoints included transfusion requirements, adverse events (AEs), and patient-reported outcomes (PROs). There were no significant differences between treatment arms in the proportion of patients achieving Hb response (68.9% for 40K, 61.7% for 80K, 65.5% for 120K, and 66.7% for DA; P > 0.41 for all comparisons) or requiring RBC transfusion, but the median Hb increment from baseline was higher in the 40K and DA arms compared to the two extended dosing EA arms, and Hb response was achieved soonest in the weekly EA arm. There were no differences in PROs or AEs. The FDA-approved schedules tested-weekly EA 40,000 U, and every 3 week DA 500 mcg-are reasonable standards for CAA therapy.

A pilot study to evaluate the safety and clinical outcomes of once-weekly epoetin alfa 80,000 u in anemic patients with cancer receiving chemotherapy

BACKGROUND

Epoetin alfa is indicated for the treatment of chemotherapy-induced anemia at doses of 150 U/kg 3 times weekly or 40,000 U once weekly. Higher starting doses may lead to higher hematologic response rates (RRs), earlier hematologic responses, and earlier identification of nonresponders. The hematologic response and safety of epoetin alfa at a starting dose of 80,000 U once weekly in anemic patients (hemoglobin [Hb] </= 11 g/dL) with nonmyeloid malignancies receiving chemotherapy were evaluated in this open-label, multicenter pilot study.

PATIENTS AND METHODS

Epoetin alfa was initiated at 80,000 U once weekly and reduced if Hb increased to > 13 g/dL or increased > 1.3 g/dL in a 2-week period during the 12-week study. The primary efficacy endpoint was major hematologic response (Hb increase >/= 2 g/dL or Hb >/=12 g/dL, independent of transfusion). Secondary endpoints were minor hematologic response (Hb increase >/= 1 g/dL but > 2 g/dL) and incidence of transfusions.

RESULTS

Of 69 patients enrolled, 47 (68%) completed the study. A majority of patients (72%) exhibited a major hematologic response with epoetin alfa 80,000 U once weekly. Mean Hb levels increased by 2.2 g/dL from baseline after 12 weeks of therapy. Six patients (8.8%) received packed red blood cell transfusions during the study. The dose of epoetin alfa was reduced, or held then reduced, per protocol in 48 patients (69.6%). Ten patients (14.5%) in the safety population experienced a total of 11 clinically relevant thrombotic vascular events.

CONCLUSION

Epoetin alfa at a starting dose of 80,000 U once weekly (with appropriate dose reductions) increased Hb level, was associated with a packed red blood cell transfusion rate > 5% after 4 weeks of therapy, and was safe and generally well tolerated in anemic patients with cancer receiving chemotherapy. The hematologic RR, however, was not markedly improved compared with previous trials with 40,000-60,000 U once weekly, perhaps partly because of the high frequency of dose reductions.

Pharmacokinetic and toxicity study of intravitreal erythropoietin in rabbits

AIM

To study the pharmacokinetics and toxicity of intravitreal erythropoietin (EPO) for potential clinical use.

METHODS

For toxicity study, 4 groups (60 rabbits) with intravitreal injection (IVit) of EPO were studied (10 U, 100 U, or 1,000 U) per eye for single injection and 0.6 U/eye (the designed therapeutic level in rabbits) for monthly injections (6X). Eye examination, flash electroretinogram (ERG), and fluorescein angiography (FA) were carried out before and after injection. The rabbits were killed for histological study at different intervals. For the pharmacokinetic study, after IVit of 5 U EPO into left eyes, 44 rabbits were killed at different intervals, and the EPO levels in vitreous, aqueous, retina and serum were analyzed by enzyme-linked immunosorbent assay.

RESULTS

At all of the time points examined, the eyes were within normal limits. No significant ERG or FA change was observed. The histology of retina remained unchanged. The pharmacokinetic profile of EPO in ocular compartments was summarized as follows. The half-life times of EPO in vitreous, aqueous and serum were 2.84, 3.24 and 2.12 d, respectively; and Cmax were 4615.75, 294.31 and 1.60 U/L, respectively. EPO concentrations in the retina of the injected eye peaked at 1.36 U/g protein at 6 h following injection, with the half-life observed to be 3.42 d.

CONCLUSIONS

IVit of EPO in a wide range is well tolerated and safe for rabbit eyes. At doses up to 10-fold higher than therapeutic levels, EPO has a pharmacokinetic profile with faster clearance, which is favorable for episodic IVit.

The myelodysplastic syndromes: diagnosis and treatment

The myelodysplastic syndromes (MDSs) are common, acquired, clinically challenging hematologic conditions that are characterized by bone marrow failure and a risk of progression to acute leukemia. These disorders can arise de novo, especially in elderly patients or, less often, as a consequence of prior chemotherapy or radiotherapy for an unrelated disease. The MDS classification systems were revised recently and updated. These refined classification and prognostic schemes help stratify patients by their risk of leukemia progression and death; this knowledge can help clinicians select appropriate therapy. Although many treatments for MDS have been proposed and evaluated, at present, only hematopoietic stem cell transplantation offers any real hope for cure, and no available therapy beyond general supportive care offers benefit to more than a minority of patients. However, recent clinical trials enrolling patients with MDS have reported encouraging results with use of newer drugs, including lenalidomide, decitabine, and darbepoetin alfa. Other exciting treatment regimens are being tested. Here, we present a contemporary, practical clinical approach to the diagnosis and risk-stratified treatment of MDS. We review when to suspect MDS, detail how to evaluate patients who may have a form of the condition, explain key features of treatments that are currently available in the United States, and summarize a general, common-sense therapeutic approach to patients with MDS.

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

BACKGROUND

Once-weekly dosing of recombinant human erythropoietin (rhEPO) in patients with myelodysplastic syndromes (MDS) has not been investigated thoroughly. We performed a clinical trial to evaluate the effects of this new dosing regimen in patients with MDS who were unresponsive to the conventional three-times-weekly schedule.

PATIENTS AND METHODS

Forty-eight patients with low- or intermediate-risk MDS were enrolled in a 12-week study. rhEPO alpha (rhEPOalpha) was administered once-weekly by subcutaneous injection with a starting dose of 40,000 U fixed dose. The drug dosage was increased to 60,000 U fixed dose if after 6 weeks there was no or suboptimal erythroid response.

RESULTS

Clinically significant responses were seen in 13 (27%) patients, with 11 improving their response after dose escalation of rhEPOalpha. Only one patient (case 23) maintains a response after a follow-up period of 14 months. All other patients had responses lasting between 10 and 43 weeks, with a median time to relapse of 20 weeks. Treatment was well tolerated, with no relevant adverse events. Response to therapy was associated with significantly higher concentrations of circulating erythroid blast-forming units and a decrease of the bone marrow fraction of apoptic CD34+ cells.

CONCLUSIONS

Once-weekly rhEPOalpha therapy results in an improvement of erythropoiesis in a subset of MDS patients who are unresponsive to conventional dosing, and may act by inhibiting apoptosis of erythroid precursors. These results warrant further investigation of this dosing regimen either alone or in combination with other agents.

The Role of Erythropoietin in the Anemia of Myelodysplastic Syndrome

Although erythropoietin (EPO) deficiency is not responsible for the anemia of myelodysplasia, pharmacologic doses of recombinant human EPO (rHuEPO, epoetin alfa) and epoetin beta have been studied extensively as treatment of anemia in myelodysplastic syndrome (MDS). When an epoetin is used as a single growth factor in patients with MDS, clinically meaningful responses occur in only a small minority of patients (16%). Patients who are transfusion-dependent are less likely to respond than patients who are transfusion-independent. Serum EPO level has a weak association with response rate and cannot be used to select or exclude patients from empirical trials of epoetins. The dose schedule commonly used as initial treatment 40,000 U/week, is consistent with clinical observations, but an optimal dose schedule has not been determined. The combination of an epoetin and granulocyte colony-stimulating factor (G-CSF) produces a higher erythroid response rate (36%) than the regimen of epoetin alone, but we have found no randomized trial data to support this point. However, the design of the clinical trials, which included adding G-CSF after epoetin alone had failed, supports the hypothesis that combined use of growth factors, rather than just higher doses of epoetin, is responsible for the high response rate observed with the combination of epoetin and G-CSF. Unfortunately, as in the case of epoetin alone, patients who are transfusion-dependent (> or =2 U red blood cells/month) are less likely to respond to combined growth factor therapy. Although the ability of patients with MDS to show an erythroid response to epoetin is of biologic interest, because of high costs and the limited response rate in transfusion-dependent patients, epoetin therapy, with or without G-CSF, cannot be regarded as a definitive therapy for the anemia of MDS.

The myelodysplastic syndrome(s): a perspective and review highlighting current controversies

The myelodysplastic syndrome (MDS) includes a diverse group of clonal and potentially malignant bone marrow disorders characterized by ineffective and inadequate hematopoiesis. The presumed source of MDS is a genetically injured early marrow progenitor cell or pluripotential hematopoietic stem cell. The blood dyscrasias that fall under the broad diagnostic rubric of MDS appear to be quite heterogeneous, which has made it very difficult to construct a coherent, universally applicable MDS classification scheme. A recent re-classification proposal sponsored by the World Health Organization (WHO) has engendered considerable controversy. Although the precise incidence of MDS is uncertain, it has become clear that MDS is at least as common as acute myelogenous leukemia (AML). There is considerable overlap between these two conditions, and the former often segues into the latter; indeed, the distinction between AML and MDS can be murky, and some have argued that the current definitions are arbitrary. Despite the discovery of several tantalizing pathophysiological clues, the basic biology of MDS is incompletely understood. Treatment at present is generally frustrating and ineffective, and except for the small subset of patients who exhibit mild marrow dysfunction and low-risk cytogenetic lesions, the overall prognosis remains rather grim. In this narrative review, we highlight recent developments and controversies within the context of current knowledge about this mysterious and fascinating cluster of bone marrow failure states.

Malignancy: Current Clinical Practice: Current Therapeutic Options in Myelodysplastic Syndromes

Myelodysplastic syndromes (MDS) are characterized initially by ineffective hematopoiesis and subsequently the frequent development of acute myelogenous leukemias (AML). During the last 15 years, important progress has been made in the understanding of the biology and prognosis of myelodysplastic syndromes. Risk-adapted treatment strategies were established due to the high median age (60-75 years) of MDS-patients and the individual history of the disease (number of cytopenias, cytogenetical changes, transfusion requirements). The use of allogeneic bone marrow transplantation for MDS patients currently offers the only potentially curative treatment, but this treatment modality is not available for the most of the "typical" MDS-patients aged >60 years. Based on in-vitro findings analyzing the potential of several agents to differentiate or to stimulate hematopoietic progenitor cells a number of therapeutic options were evaluated in clinical trials: hematopoietic growth factors (e.g. erythropoietin, G-CSF), differentiation inducers (e.g. retinoids), or cytoprotective substances (amifostine). The role of immunsuppressive agents (antithymocyte globulin, cyclosporine A) either alone or in combination is being actively investigated. Using intensive cytotoxic treatment in patients with advanced MDS or AML after MDS complete remission rates comparable with those known from the treatment of de novo AML were reported. The therapy related toxicity (early death rate <10%) was reduced by using G-CSF given prior ("Priming") and/or after the cytotoxic treatment.

Treatment of anaemia in myelodysplastic syndromes with prolonged administration of recombinant human granulocyte colony-stimulating factor and erythropoietin

Treatment with recombinant human erythropoietin (rhEPO) improves anaemia in approximately 20% of the patients with myelodysplastic syndromes (MDS). Recent reports suggest that a combination treatment with rhEPO plus recombinant human granulocyte colony-stimulating factor (rhG-CSF) given for up to 18 weeks may result in a higher erythroid response rate than with rhEPO alone. We investigated the potential advantage of an even more prolonged schedule of combined rhG-CSF and rhEPO treatment to obtain and maintain stable responses. In a phase II study, 33 patients with MDS [17 with refractory anaemia (RA), eight with RA with ringed sideroblasts (RARS), eight with RA with excess blasts (RAEB) with bone marrow blast counts less than 20%] were scheduled to receive at least 36 weeks of combined therapy with rhG-CSF and rhEPO. Seventeen of 28 evaluable patients demonstrated an erythroid response [61%; 95% confidence interval (CI) 41-78] after 12 weeks of treatment. The erythroid response rate was 80% (20 of 25 evaluable patients; 95% CI 59-93) after 36 weeks. Seven of these responses developed between week 12 and week 36, whereas two initially responding patients became refractory. The cytokine therapy was generally well tolerated. Nineteen of the 20 patients responding after 36 weeks continued to be treated with both cytokines. After 1 year and 2 years of continuous combined treatment, 50% of the initially included patients showed a continuing response. Our results suggest that a prolonged combination treatment with rhG-CSF and rhEPO is highly effective in achieving a stable and long-lasting erythroid response in many patients with MDS and low blast count.

Effect of recombinant human erythropoietin combined with granulocyte/ macrophage colony-stimulating factor in the treatment of patients with myelodysplastic syndrome

This randomized, placebo-controlled trial was designed to assess the efficacy and safety of therapy with granulocyte-macrophage colony-stimulating factor (GM-CSF) and erythropoietin (epoetin alfa) in anemic, neutropenic patients with myelodysplastic syndrome. Sixty-six patients were enrolled according to the following French–American–British classification: refractory anemia (20), refractory anemia with excess blasts (35), refractory anemia with ringed sideroblasts (9), and refractory anemia with excess blasts in transformation (2). Patients were stratified by their serum erythropoietin levels (less than or equal to 500 mU/mL, n = 37; greater than 500 mU/mL, n = 29) and randomized, in a 2:1 ratio, to either GM-CSF (0.3-5.0 μg/kg·d) + epoetin alfa (150 IU/kg 3 times/wk) or GM-CSF (0.3-5.0 μg/kg·d) + placebo (3 times/wk). The mean neutrophil count rose from 948 to 3831 during treatment with GM-CSF ± epoetin alfa. Hemoglobin response (increase greater than or equal to 2 g/dL, unrelated to transfusion) occurred in 4 of 45 (9%) patients in the GM-CSF + epoetin alfa group compared with 1 of 21 (5%) patients with GM-CSF + placebo group (P = NS). Percentages of patients in the epoetin alfa and the placebo groups requiring transfusions of red blood cells were 60% and 92%, respectively, for the low-endogenous erythropoietin patients and 95% and 89% for the high-endogenous erythropoietin patients (P = NS). Similarly, the average numbers of units of red blood cells transfused during the 12-week study in the epoetin alfa and the placebo groups were 5.9 and 9.5, respectively, in the low-endogenous erythropoietin patients and 9.7 and 8.6 in the high-endogenous erythropoietin patients (P = NS). GM-CSF ± epoetin alfa had no effect on mean platelet count. Treatment was well tolerated in most patients, though 10 withdrew from the study for reasons related predominantly to GM-CSF toxicity.

A randomized double-blind placebo-controlled study with subcutaneous recombinant human erythropoietin in patients with low-risk myelodysplastic syndromes

To evaluate the effect of recombinant human erythropoietin (rHuEpo) on the haemoglobin level and transfusion requirement in low-risk myelodysplastic syndromes (MDS), 87 patients were enrolled in a randomized double-blind placebo-controlled study, 44 patients were assigned to epoetin alpha (150 U/kg/d s.c. for 8 weeks) and 43 to placebo arms. MDS types were homogenous in both groups: refractory anaemia (RA) 47.7-48.8%. refractory anaemia with ringed sideroblasts (RAS) 20.5-25.6%, refractory anaemia with excess of blasts (RAEB) (blasts < 10%) 31.8-25.6%, 14/38 evaluable patients responded to epoetin alpha versus 4/37 to placebo (P=0.007). 50% of RA responded to epoetin alpha versus 5.9% to placebo (P=0.0072), RAS 37.5% v 18.2% (P=0.6) and RAEB 16.7% v 11.1% (P=1.00). 60% of non-pretransfused patients responded to epoetin alpha (Hb 8.35< or = 0.73 to 10.07+/-1.87 g/dl), whereas a slight decrease was observed in the placebo group (8.4+/-0.66 to 8.19+/-0.92 g/dl) (P=0.0004). Percentage of transfused patients was similar in both arms. Basal erythropoietin (Epo) serum levels > 200 mU/l predicted for a non-response. At week 4 sTfR levels were increased > 50% in responders (P=0.013), whereas an increase < 18% predicted for non-response (P=0.006). Leucocyte and platelet counts were not influenced by epoetin alpha treatment. Adverse events occurred in 31.8% of the rHuEpo-treated versus 42.99%) of the placebo-treated patients (P=0.2), and seven patients did not complete the course. In conclusion, rHuEpo was effective in the treatment of low-risk MDS. RA subtype, no transfusions prior to rHuEpo therapy, and low basal Epo levels were associated with higher probability of response. Soluble transferrin receptor level at the fourth week was an early predictor of response.

Hematopoietic growth factors for the treatment of myelodysplastic syndromes

Administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF), rh granulocyte-macrophage colony-stimulating factor (rhGM-CSF) or rh interleukin-3 (rhIL-3) effectively stimulate and expand marrow myelopoiesis resulting in a dose-dependent increment of peripheral blood neutrophils in most patients with myelodysplasias (MDS). Clinical outcome with fewer infections have been reported in a few studies using rhG-CSF or rhGM-CSF, including a large randomized, controlled trial with rhGM-CSF. Clinical effective stimulation of megakaryopoiesis and erythropoiesis are however infrequent. Recently, rh erythropoietin (rhEpo) has been used to overcome the ineffective erythropoiesis in MDS to reduce transfusions needed. However, the efficiency has been low in most studies with marked differences in response rates. The most impressive clinical results were obtained in patients with milder forms of MDS combined with low prestudy endogenous S-Epo levels. The possible synergistic effect of combining rhEpo with rhG-CSF or rhGM-CSF has been studied with erythropoietic response rates of about 40%. The safety of the cytokine administration seems acceptable with no significant stimulation of leukemic myelopoiesis and subsequent progression into overt acute myeloid leukemia. In conclusion, combinations of hematopoietic growth factors may be of clinical benefit in some patients with MDS. However, due to the cost and unpredictable clinical outcome there is a need for extended laboratory research to understand the functional defects of MDS stem cells and progenitors.

Clinical use of hematopoietic growth factors in the myelodysplastic syndromes

Recent advances in the molecular genetics of myelodysplastic syndromes (MDS) have shed new light on the pathogenesis of MDS allowing a better understanding of the defects of differentiation of the transformed clone and suppression of normal hematopoiesis. The clinical hematologist, however, continues to be challenged with the treatment of patients with MDS. Pancytopenia and defective function of neutrophils and platelets lead to a high risk of infectious and hemorrhagic complications. The progression to acute myeloid leukemia adds to morbidity and mortality. Supportive care including red blood cell and platelet transfusions are still the cornerstone of therapeutic management. While prophylactic administration of G-CSF or GM-CSF cannot be recommended, treatment of febrile neutropenia might benefit from administration of G-CSF in addition to antibiotics. Administration of high-dose erythropoietin will improve erythropoiesis in around 20% of the patients, mainly in those with rather preserved erythroid function and no or low transfusion need. Coadministration of erythropoietin with either G-CSF or GM-CSF could increase the response rate. Allogeneic stem cell transplantation still is the only curative treatment and prolongs survival. Intensive chemotherapy for advanced MDS is possible with an acceptably low rate of early death and a complete remission rate between 45% to 60%, while initial results of autologous transplantation are promising.

Investigation of the influenza-like symptoms associated with recombinant human erythropoietin therapy

The mechanism by which fever and influenza-like symptoms occur, after the administration of recombinant human erythropoietin (rHuEPO) to patients on continuous ambulatory peritoneal dialysis, was investigated. Peripheral blood mononuclear cells, obtained from two patients with fever and/or influenza-like symptoms related to the administration of rHuEPO for the treatment of anaemia were cultured with or without rHuEPO (100, 200, and 300 U/ml). Production of interleukin-1 beta and tumour necrosis factor-alpha was higher in cultures with rHuEPO than in cultures without rHuEPO, although the dose relationships were not clear. These findings suggest that increased production of interleukin-1 beta and tumour necrosis factor-alpha 1, induced by administration of rHuEPO, may cause fever and influenza-like symptoms.

Haemodynamic changes measured by transthoracic bioimpedance during treatment with recombinant human erythropoietin

Hypertension complicates the treatment of anaemia of chronic renal failure with recombinant human erythropoietin (EPO) in some patients. We conducted a prospective study measuring changes in cardiac index (CI) and systemic vascular resistance index (SVRI) in 29 patients from before commencement of EPO to attainment of target haemoglobin concentration. We used the operator-independent technique of trans-thoracic bioimpedance. The group of patients who developed EPO-induced hypertension (EpHT) were separately analysed and compared with the group who had no change in blood pressure (NC). Our results showed there was a significant rise in SVRI after treatment in EpHT group patients but in the NC group there was a small fall. CI increased significantly in the NC group after treatment but no change was recorded in the EpHT group. These findings clearly demonstrate how the cardiovascular changes differ in patients who develop EPO-induced hypertension.

The use of r-HuEpo in the treatment of anaemia related to myelodysplasia (MDS)

One hundred and sixteen (116) anaemic patients with myelodysplastic syndromes (MDS) were treated with recombinant human erythropoietin (r-HuEpo) in an open-label, multicentre, compassionate treatment trial; 100 patients received therapy for > or = 4 weeks and were evaluable for efficacy. The distribution of FAB subtypes was: 44 RA, 40 RARS, eight RAEB, two RAEB-t, one CMML, and five not specified. Mean baseline haematocrit was 24.5%, and the mean prestudy transfusion requirement in the 12 weeks immediately prior to study entry was 6.5 units. r-HuEpo treatment was initiated at a dose of 150 U/kg three times weekly, with dose escalations of 50 U/kg monthly (up to 300 U/kg 3x/week) permitted if the haematocrit failed to rise. Response to therapy was defined as either an increase in haematocrit of > or = 6 percentage points over baseline, unrelated to transfusion, or a > or = 50% decrease in transfusion requirement in the last 3 months of study treatment, compared to the baseline period (12 weeks). By these criteria, 28% (28/100) of patients responded to r-HuEpo treatment. Overall, 86% (24/28) of patients responding to therapy had baseline Epo levels < or = 100 mU/ml. Response rates by FAB subtype were: RA 39% (17/44), RARS 17.5% (7/40) and RAEB 12.5% (1/8). Additionally, a 54% (15/28) response rate was seen in RA patients with baseline Epo levels < or = 100 mU/ml. Responses to therapy were durable and generally occurred at r-HuEpo doses of 150-200 U/kg t.i.w. There were no reports of thrombosis, seizures or therapy-related hypertension. The data show that patients with MDS, especially those with the RA and RARS subtypes, can benefit from treatment with r-HuEpo. Those patients with baseline Epo levels < or = 100 mU/ml were most likely to respond to therapy.

Sequential administration of recombinant human granulocyte-macrophage colony-stimulating factor and human erythropoietin for treatment of myelodysplastic syndromes

Treatment of myelodysplastic syndromes (MDS) with recombinant human erythropoietin (Epo) is successful in only 10% to 25% of patients. We performed a pilot study in 10 anaemic patients with MDS to examine whether sequentially applied recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) and Epo improves haemoglobin levels and/or reduces red blood cell transfusion requirements. Morphological diagnoses of patients were refractory anaemia (RA) in 3 cases, RA with ring sideroblasts in 3 cases and RA with excess blasts in 4 cases. GM-CSF was given subcutaneously at a dose of 150 micrograms/m2/d during the initial 10 days. From day 11, Epo was administered by subcutaneous injections for 8 weeks at a dose of 100 U/kg/d and subsequently at an escalated dose of 200 U/kg/d in 3 patients. Changes in reticulocyte counts, haemoglobin levels, RBC support and ferrokinetic parameters were compared with pretreatment values. Two out of 8 evaluable patients showed a rise in haemoglobin levels at week 8 and 10, respectively, and lost their transfusion dependency for a period of 13 and 27 weeks. In 1 patient, haemoglobin level increased only after dose escalation of Epo (200 U/kg/d). Leukocyte counts remained uneffected by treatment with Epo, while 1 patient showed a 4-fold increase in platelet numbers. Toxicity was mild. Two patients died of pneumonia and global heart failure, respectively, unrelated to growth factor therapy. Based on this pilot study, we conclude that sequential treatment with GM-CSF and Epo does not increase erythroid responses in anaemic patients with MDS. Because of the delayed increase in haemoglobin in both responders, we surmise that the beneficial effects were induced by Epo alone.

Therapy with recombinant human erythropoietin in patients with myelodysplastic syndromes

We conducted a Phase I-II trial of recombinant human erythropoietin-beta (rhEPO) in patients with myelodysplastic syndrome (MDS). Patients with anemia and pathologically confirmed MDS were eligible for the study. Treatment consisted of rhEPO by subcutaneous injection thrice weekly for 6 weeks at one of three dose levels (100 U/kg (three patients), 200 U/kg (three patients) and 400 U/kg (14 patients)). Ferrous sulfate (325 mg po tid) was also administered if the transferrin saturation was below 30% (two patients). Patients were monitored with weekly CBC, white cell differential, and reticulocyte counts. Bone marrow examinations were performed at the conclusion of the treatment period and after a 2 week washout period. Patients who responded to therapy were continued on rhEPO at the same dose for 6 additional months. Response criteria included: 50% reduction in transfusion requirements compared with the 6 week pre-study period; doubling of reticulocyte count that was maintained on two determinations at least 1 week apart; or an increase in hemoglobin by at least 1.2 gm/dl without transfusions. Pre-treatment factors potentially predictive of response were analyzed by univariate analysis and in a multivariate fashion by classification and regression trees. Seven of the twenty patients sustained an untransfused rise in serum hemoglobin > or = 1.2 gm/dl. Four of the sixteen patients (including three of seven patients experiencing a rise in serum hemoglobin) who were transfusion-dependent prior to the study achieved a reduction or elimination of their transfusion requirements. Five of thirteen patients who received rhEPO during the extension phase had a continued response. A low baseline erythropoietin level (< 50 mU/ml) was the best predictor of hemoglobin response when controlling for other variables. rhEPO has a role in the treatment of certain patients with MDS, particularly in those whose endogenous serum erythropoietin levels are not markedly elevated.

A review of 76 patients with myelodysplastic syndromes treated with danazol

BACKGROUND

Treatment of myelodysplastic syndromes (MDSs) remains unsatisfactory. A limited number of reports provide contradictory information on whether danazol, a synthetic androgen, may be useful in patients with MDS.

METHODS

Between 1984 and 1992, 76 patients were treated with danazol (Danatrol, Winthrop) in an open nonrandomized study. Clinical status, blood counts, differential marrow cell counts, transfusion requirements, and liver enzymes were monitored at 3-month intervals during and 6 months after discontinuation of therapy. The authors present the retrospective analysis of this cohort of patients.

RESULTS

This study shows a limited usefulness of danazol in patients with MDS. Blood counts were not significantly changed during danazol administration; neither were transfusion requirements. Overall survival and the rate of leukemic transformation were not affected when compared with 50 untreated patients or with data available in the literature. An increase in platelet numbers in four patients and in hemoglobin level in one patient was observed; these patients were unremarkable and were not transfused before initial danazol therapy; therefore, changes in blood counts were of limited clinical significance. The search for subgroups of patients likely to have a favorable response was unsuccessful. Side effects of danazol were limited. In addition, this study provides information on the frequency of antiplatelet antibodies and other autoantibodies in patients with MDS.

CONCLUSIONS

This study does not support a positive effect of danazol in patients with MDS during long term follow-up. Anecdotal positive evolution in a few patients cannot be formally ascribed to danazol. These results should be interpreted by comparison with previous publications that report on small numbers of patients with limited follow-up. Based on these data, the authors cannot recommend the systematic use of danazol in MDS.