Tapering and discontinuation of thrombopoietin receptor agonists in immune thrombocytopenia: Real-world recommendations.

Thrombopoietin receptor agonists (TPO-RAs) are currently indicated for continuous treatment of chronic primary immune thrombocytopenia (ITP). However, there is growing evidence that TPO-RAs can also trigger sustained response in 10-30% of cases after treatment tapering and discontinuation. Therefore, at least for selected responding patients, it might be rational to plan TPO-RA interruption to exploit off-treatment response. Intriguingly, complete or partial responses with TPO-RAs are frequently observed when treatments are initiated early, suggesting that unknown immune-related mechanisms may be involved in this phenomenon. The sustained responses observed after interruption of TPO-RAs may be interpreted as a recovery of immunological tolerance; thus, the re-establishment of immunological equilibrium might be primarily responsible for the observed off-treatment effect. Importantly, these findings may indicate that anticipated TPO-RA usage can lead to improved responses, and that optimized tapering and interruption in selected patients can furthermore improve prognoses. On the base of this rationale, a series of real-life considerations have been generated by a panel of Experts to elucidate possible novel criteria and modalities to identify subgroups of patients who can benefit from tapering and/or discontinuation of TPO-RAs. Towards this aim, the results of a survey of ITP experts are herein reported, reflecting a snapshot of current real-life experience on early discontinuation of TPO-RA-based therapy. The present manuscript also highlights the importance of future translational studies on novel prognostic and predictive biomarkers that can stratify patients and facilitate the clinical choice for second-line treatment of ITP.

Combination treatment of flag with non-pegylated liposomal doxorubicin (MYOCET(TM)) in elderly patients with acute myeloid leukemia: a single center experience.

The incidence of acute myeloid leukemia (AML) increases with age, but results of intensive chemotherapy in elderly patients are disappointing. Non-pegylated liposomal formulations of doxorubicin (Myocet™) have been developed with the aim of reducing systemic and cardiac toxicity especially in the elderly. We evaluated the efficacy and toxicity profiles of fludarabine, cytarabine and granulocyte colony-stimulating factor (FLAG) regimen given in association with Myocet™ in 35 patients with AML, median age 69 years (range 61-83 years). Nineteen (54.3%) had newly-diagnosed AML, twelve (34.3%) patients had secondary AML (ten with Myelodisplastic Syndrome, two with Primary Myelofibrosis) and 4 (11.4%) patients had had a late relapse (>12 months) of AML. Complete remission (CR) and partial remission (PR) were obtained in twenty-two (63%) and 3 (8.5%) patients, respectively. Seven (20%) patients showed a resistant disease. There were 3 early deaths (8.5%). Six patients (17%) experienced severe cardiovascular toxicity. The median overall survival (OS) was 12 months (range 1-52 months) with a median disease-free survival (DFS) of 20 months (range 1-48 months). One-year and two-year DFS were 78.9% and 26.7%, respectively. This study demonstrates that in elderly patients with AML, FLAG-Myocet combination shows promising efficacy response with acceptable toxicity, enabling most patients to receive further treatments, including transplantation procedures.

Adding growth factors or interleukin-3 to erythropoietin has limited effects on anemia of transfusion-dependent patients with myelodysplastic syndromes unresponsive to erythropoietin alone.

BACKGROUND AND OBJECTIVES: Recombinant erythropoietin (r-EPO) induces erythroid responses in patients affected by myelodysplastic syndromes (MDS). However, the response rate declines to 10-15% in MDS with substantial transfusion needs. Both in vitro and in vivo studies have suggested that the addition of growth factors (G-CSF, GM-CSF) or interleukin-3 (IL-3) may potentiate the effect of r-EPO on dysplastic erythropoiesis. The aim of this study was to evaluate the effects of the combination of r-EPO with G-CSF, GM-CSF or IL-3 on the anemia of heavily transfusion-dependent MDS patients, previously unresponsive to r-EPO alone. PATIENTS AND METHODS: Sixty patients with transfusion-dependent MDS, already treated without significant erythroid response with r-EPO alone, were scheduled to receive, for at least 8 weeks, r-EPO subcutaneously at the dose of 300 U/kg t.i.w. in combination with G-CSF (300 microcg s.c. t.i.w., 27 patients), or GM-CSF (300 microcg s.c. t.i.w., 23 patients), or IL-3 (5 microcg/kg s.c. t.i.w., 10 patients), after a two-week pre-phase during which G-CSF, GM-CSF and IL-3 were administered daily at the same dose, as single drugs. RESULTS: Ten patients were not evaluable for erythroid response because of relevant side effects related to GM-CSF or IL-3 administration. Overall, among 50 patients who completed the study, there were 3 erythroid responses (as determined by complete abolition of red-cell transfusions): 1 (4%) in the G-CSF + r-EPO and 2 (10.5%) in the GM-CSF + r-EPO treated groups. No patient responded to the combination of r-EPO + IL-3. All responders had inappropriate serum levels of endogenous EPO and a relatively short disease duration. Both responders to GM-CSF + r-EPO developed acute myeloid leukemia 2-9 months after the start of the combined therapy. A third elderly patient, treated with the same association, developed marrow hypoplasia. A significant increase in leukocyte count occurred in 96% of patients who received r-EPO + G-CSF, 78.9% of those treated with r-EPO + GM-CSF and 66% of subjects receiving r-EPO + IL-3. A significant increase in platelet count was observed in a single patient receiving r-EPO and GM-CSF, while a slight decrease in platelet count with respect to baseline levels occurred in about 20% of patients. INTERPRETATION AND CONCLUSIONS: Our results suggest that the combination of r-EPO with G-CSF, GM-CSF or IL-3, at least at the doses and schedules employed in the present study, has limited efficacy on the anemia of heavily transfusion-dependent MDS patients previously unresponsive to r-EPO alone. However, in this setting of patients, the combination of G-CSF or GM-CSF + r-EPO may occasionally be effective in subjects with low circulating levels of serum EPO and short disease duration.

Synergistic effect of desferrioxamine and recombinant erythropoietin on erythroid precursor proliferation in chronic renal failure.

BACKGROUND: Desferrioxamine (DFO) has been suggested to improve erythropoiesis in end-stage renal failure independently of its aluminium (Al)-chelating effect. A possible synergistic effect of DFO and recombinant human erythropoietin (r-HuEpo) could be very useful in treating anaemia of chronic renal failure. METHODS: In order to verify whether a synergistic action of DFO and r-HuEpo exists, we enrolled 11 patients undergoing chronic haemodialysis and r-HuEpo treatment. All had a negative DFO test, very low serum Al levels (< 20 microg/l), ferritin > 100 ng% and iPTH < 200 pg/l. Samples were drawn for a basal erythroid precursor (burst-forming unit-Erythroid, BFU-E) evaluation. After isolation by Ficoll Hypaque, a 14 day incubation was carried out with: (i) r-HuEpo 3 U/ml; (ii) r-HuEpo 30 U/ml; and (iii) r-HuEpo 30 U/ml + DFO 167 microg/ml. Patients then received 5 mg/kg DFO infused during the last hour of each dialysis session for 12 weeks. New BFU-E evaluations were performed after 2, 6 and 12 weeks of treatment. BFU-E colonies were counted in duplicate with an inverted microscope after 14 days. Haemoglobin (Hb), ferritin, transferrin, reticulocytes, hypochromic erythrocytes, soluble transferrin receptor and serum erythropoietin were also evaluated at the same time. RESULTS: High dose r-HuEpo achieved greater proliferation than low dose r-HuEpo cultures during all phases of the study. At baseline, r-HuEpo and DFO culture had a greater number of colony units than high dose r-HuEpo culture ( 103.7 +/- 50.2 vs 95.1 +/- 50.5, NS). This increase became significant after 2 weeks (145 +/- 59.3 vs 122.9 +/- 59.6, P < 0.02), and remained so at 6 (167.4 +/- 60.3 vs 149 +/- 55.6, P < 0.01) and 12 weeks (191 +/- 64.5 vs 155.1 +/- 56.3, P < 0.01). An increased proliferation was observed after DFO therapy in all culture studies: low dose r-HuEpo culture increased from 69.4 +/- 38.2 to 86.6 +/- 48.5, 115 +/- 39 and 123 +/- 46; high dose r-HuEpo culture increased from 95.1 +/- 50.5 to 122.9 +/- 59, 149 +/- 55.6 and 155.1 +/- 56.3 and r-HuEpo plus DFO culture from 103.7 +/- 50.2 to 145 +/- 59.3, 167 +/- 60.3 and 191 +/- 64.5 at 2, 6 and 12 weeks, respectively (all P < 0.01 by ANOVA). Haemoglobin, reticulocytes and soluble transferrin receptor were slightly increased, while ferritin decreased. Hypochromic erytrocytes were variable. CONCLUSIONS: DFO increases erythroid precursor proliferation and has a synergistic in vivo effect with r-HuEpo in patients with chronic renal failure. Further investigations are needed to evaluate whether such an effect may have clinical application.

Predictive parameters for mobilized peripheral blood CD34+ progenitor cell collection in patients with hematological malignancies.

In order to investigate what is the best single parameter to predict the leukapheretic yield of circulating CD34+ progenitor cells, we retrospectively analyzed data from 68 patients with hematological malignancies who underwent mobilizing therapy. Three main parameters were monitored: total white blood cell (WBC), CD34+ cells, and monocyte counts in peripheral blood (PB) at the same day and at the preceding day of the apheretic procedure. Linear regression analysis revealed a strong correlation between CD34+ cell value in PB just before harvest and the number of CD34+ cells collected (P < 0.0001), but not at the preceding day. Monocyte PB concentration and absolute WBC count did not correlate with CD34+ cells harvested, at the preceding day of leukapheresis as well as at the same day of the procedure. The number of CD34+ cells in mobilized PB at the same day of harvest evidenced a very good capacity of predicting the value of harvested CD34+ cell number after collection, while WBC and monocyte count displayed quite a wide dispersion of results. In particular, an amount greater than 50/microL of circulating CD34+ cells ensured the best collections. Finally, CD34+ and CFU-GM content evaluated for each apheresis showed a strong reciprocal correlation (r 0.78; P < 0.0001). We conclude that the absolute number of CD34+ cells at the day of leukapheresis is the only parameter for identifying the exact timing for apheresis and predicting the amount of peripheral blood progenitor cells (PBPCs) that will be collected. In this setting, WBC and monocyte counts, at the day of collection or at the preceding day, are not useful tools.

Desferrioxamine improves burst-forming unit-erythroid (BFU-E) proliferation in haemodialysis patients.

BACKGROUND: In chronic renal failure, desferrioxamine (DFO) may improve erythropoiesis independent from its aluminium (Al) chelating effect. The mechanism of this action is still unknown. METHODS: To verify whether DFO influences proliferation of erythropoietic precursors, we studied 10 patients on chronic haemodialysis, free from malignancies or other haematological diseases, iron deficiency, bone marrow fibrosis, and Al toxicity. Al accumulation was excluded by the DFO test. Peripheral blood samples were drawn for basal burst-forming unit erythroid (BFU E) assay. Mononuclear cells were isolated by density gradient centrifugation with Ficoll Hypaque, and incubated for 15 days with three different experimental conditions: (a) low-dose recombinant human erythropoietin (rHuEpo) (3 U/ml); (b) high dose rHuEpo, (30 U/ml); (c) both DFO (167 microg/ml) and rHuEpo (3 U/ml). We determined TIBC, transferrin, ferritin, reticulocytes, hypochromic erythrocytes, soluble transferrin receptor (sTR), haemoglobin (Hb), and haematocrit (Hct) at baseline and then every 14 days. Patients received 5 mg/kg DFO infused during the last hour of each dialysis session for 6 weeks; six patients remained in the study for an additional 6 more weeks. BFU E assays were set up after 6 and 12 weeks of DFO therapy. RESULTS: At baseline DFO had small effect on BFU E proliferation (33.9+/-25 vs 30.4+/-25.9) and high-dose rHuEpo had a significant effect (45.15+/-27 vs 30.4+/-25.9, P<0.01). After 6 weeks of DFO therapy a significant increase in BFU E proliferation was observed in all culture conditions (78.25+/-32 vs 30.45+/-25.9 standard culture, P<0.01; 110.9+/-30 vs 45.15+/-27 high dose rHuEpo, P<0.01; 98.75+/-32 vs 45.15+/-27 DFO culture, P<0.01). Moreover, the increase in BFU E proliferation was significant greater with DFO culture than standard culture (P<0.01). The same trend was found at the third BFU E assay, performed in only six patients, when all culture conditions showed a further increase of erythroid precursor proliferation. However, the DFO culture was not significantly greater than the standard culture, while the high-dose rHuEpo was significantly greater than the DFO culture. Patients in group I (n=10), had a significant increase in reticulocytes (1.5+/-0.6 vs 1.72+/-0.3, P<0.01) and of hypochromic erythrocytes (HE) (5.6+/-5.1 vs 14.4+/-12.7, P<0.01), while sTR, Epo, Hb, and Hct were only minimally increased. Ferritin decreased significantly (448+/-224 vs 196+/-215, P<0.01) and TIBC and transferrin were unchanged. CONCLUSIONS: Thus DFO increases erythroid activity by BFU E proliferation and increases reticulocytes in haemodialysis patients. Such an effect may be related to increased iron utilization. DFO may be a useful tool for anaemic patients with good iron stores and without Al overload.

Clinical results of recombinant erythropoietin in transfusion-dependent patients with refractory multiple myeloma: role of cytokines and monitoring of erythropoiesis.

Recombinant erythropoietin (r-EPO) was administered to 37 patients with advanced, transfusion-dependent and chemo-resistant multiple myeloma (MM), at the fixed dose of 10,000/U s.c., 3 times a week, for 2 months. Thirteen patients (35.1%) achieved a significant response in terms of complete abolition of red cell transfusions. Factors significantly predictive of response were: a) inappropriate production of endogenous EPO, as expressed by a reduced observed/predicted ratio; b) presence of a consistent number of circulating erythroid precursors BFU-E; c) low serum levels of tumor necrosis factor (TNF) and interleukin-1 (IL-1), cytokines with inhibitory activity on erythropoiesis; d) a single line of previously received chemotherapy. Renal failure, bone marrow plasma cell infiltration, serum levels of IL-6 and other main clinical and laboratory parameters did not affect significantly the response to r-EPO. High fluorescence reticulocytes (HFR) and soluble transferrin receptor (sTfR) values were useful to detect an early stimulation of erythropoiesis in responders, while a high percentage of circulating hypochromic erythrocytes (HE), as assessed by an automated counter, identified those patients developing functional iron deficiency during r-EPO treatment. We conclude that about one-third of severely anemic patients with advanced MM, unresponsive to chemotherapy, may benefit by r-EPO therapy. The clinical management of these patients can be accomplished using non-invasive parameters, such as sTfR, HFR and HE.

All-trans retinoic acid in combination with alpha-interferon and dexamethasone for advanced multiple myeloma.

The in vitro inhibitory effect of all-trans retinoic acid (ATRA) on myeloma cell growth may be synergistically potentiated by the activity of dexamethasone (DEX) and alpha-interferon (IFN). We treated 10 patients with advanced, refractory multiple myeloma (MM) using a combination of ATRA (100 mg p.o., once a day for two weeks every month), DEX (40 mg i.v., for 4 days every 4 weeks) and IFN (3 MU s.c., three times a week). Eight patients completed at least three months of treatment and were evaluable for response. Two of them showed a partial response which persists after 15 to 17 months. Three patients experienced a stable plateau phase of 4 to +11 months, with a significant improvement in the performance status and bone pain. Progressive disease was seen in the remaining three patients. We conclude that the association of ATRA, DEX and IFN warrants further consideration in MM patients.

Effective autologous peripheral blood stem cell transplantation in plasma cell leukemia followed by T-large granular lymphocyte expansion: a case report.

We report a case of de novo plasma cell leukemia, resistant to standard VMD (vincristine, mitoxantrone, dexamethasone) and CVP (cyclophosphamide, vincristine and prednisone) protocols, treated with a chemotherapy intensification regimen (high-dose cyclophosphamide, modified EDAP, Dexa-BEAM) and peripheral blood stem cell transplantation, performed using fractionated total body irradiation and high dose melphalan. The patient is currently alive and well, in very good partial remission 12 months after transplant and 22 months after diagnosis, disclosing a significant proportion of bone marrow and peripheral blood CD3+, CD8+, CD57+, HLA-Dr+ large granular lymphocytes with cytotoxic activity against neoplastic plasma cells.

Prognostic relevance of serum thymidine kinase in primary myelodysplastic syndromes: relationship to development of acute myeloid leukaemia.

The aim of this study was to evaluate the possible prognostic relevance of thymidine kinase serum levels (s-TK), an indirect marker of proliferative activity, in myelodysplastic syndromes (MDS). S-TK levels were monitored by means of a radioenzyme assay in 90 patients affected by MDS (22 refractory anaemia, RA; 17 RA with ring sideroblasts, RARS; 21 RA with blast excess, RAEB; 15 RAEB in transformation, RAEB-T; 15 chronic myelomonocytic leukaemia, CMMoL). Mean s-TK levels (U/microliter) measured at diagnosis were 11.9 +/- 12.6 for RA, 11.4 +/- 13.6 for RARS, 19.9 +/- 28.4 for RAEB, 39.6 +/- 34.3 for RAEB-T and 77.7 +/- 69.7 for CMMoL (normal values < 5 U/microliter). With the only exception of a weak relationship with lactate dehydrogenase, no correlation was found between initial s-TK values and other clinical or laboratory parameters, such as age, haemoglobin, white blood cell or platelet count, percentage of bone marrow blasts. MDS patients with s-TK > 38 U/microliters, a cut-off level selected by means of ROC statistical analysis, showed a significantly shorter survival than those with s-TK < 38 U/microliter (8.2 v 37.4 months, respectively; P < 0.0001). In particular, transformation in acute myeloid leukaemia (AML) occurred in 17/21 (81%) of patients with s-TK > 38 U/microliters and 9/69 (13%) of those with lower levels at diagnosis (P < 0.0001), independently of FAB subtype. High s-TK levels were also useful to predict evolution in AML during the course of the disease in patients with normal initial values. Multivariate analysis confirmed the independent prognostic value of s-TK on both overall survival and risk of acute transformation. We conclude that s-TK may be an important prognostic factor in MDS, strongly correlated with development of AML.

Modifications of erythropoiesis in myelodysplastic syndromes treated with recombinant erythropoietin as evaluated by soluble transferrin receptor, high fluorescence reticulocytes and hypochromic erythrocytes.

BACKGROUND: The aim of this study was to evaluate changes in erythropoiesis induced in vivo by recombinant erythropoietin (r-EPO) treatment in myelodysplastic syndromes (MDS), by means of some new, non invasive laboratory parameters. PATIENTS AND METHODS: Serum levels of soluble transferrin receptor (STR), a marker of total marrow erythroid activity, and automated detection of high fluorescence reticulocytes (HFR) and hypochromic erythrocytes (HE) (respectively, indexes of effective erythropoiesis and functional iron deficiency) were longitudinally measured in 25 MDS patients treated with r-EPO, and then correlated with conventional clinical and laboratory features. RESULTS: Stimulation of erythropoiesis was documented in 8 patients, whose serum STR levels showed a significant, early (within 16 days) increase during treatment with r-EPO. However, only 3 of these patients demonstrated a concomitant rise in HFR, and these were the only subjects who experienced a significant clinical response. Two of these patients also developed a functional iron deficiency while on treatment, as documented by an increase in HE, despite normal serum iron, transferrin saturation and even very high levels of ferritin. They needed iron supplementation to maintain the response to r-EPO. No variation in STR, HFR or HE occurred in the remaining 17 unresponsive patients during at least two months of treatment. Serum levels of thymidine kinase, as aspecific marker of cellular proliferative activity, paralleled those of STR. No correlation was found between STR, HFR or HE and serum levels of endogenous EPO, hemoglobin or transfusion requirements in MDS patients. CONCLUSIONS: These findings suggest that there is a heterogeneous and complex pattern of erythroid response in MDS patients treated with r-EPO. In addition, our results indicate that STR, HFR and HE may provide useful information for the clinical management of these patients.