Soluble Urokinase-Type Plasminogen Activator Receptor (suPAR) and Growth Differentiation Factor-15 (GDF-15) Levels Are Significantly Associated with Endothelial Injury Indices in Adult Allogeneic Hematopoietic Cell Transplantation Recipients.

Hematopoietic stem cell transplantation-associated thrombotic microangiopathy (HSCT-TMA) and graft-versus-host disease (GvHD) represent life-threatening syndromes after allogeneic hematopoietic stem cell transplantation (allo-HSCT). In both conditions, endothelial dysfunction is a common denominator, and development of relevant biomarkers is of high importance for both diagnosis and prognosis. Despite the fact that soluble urokinase plasminogen activator receptor (suPAR) and growth differentiation factor-15 (GDF-15) have been determined as endothelial injury indices in various clinical settings, their role in HSCT-related complications remains unexplored. In this context, we used immunoenzymatic methods to measure suPAR and GDF-15 levels in HSCT-TMA, acute and/or chronic GVHD, control HSCT recipients, and apparently healthy individuals of similar age and gender. We found considerably greater SuPAR and GDF-15 levels in HSCT-TMA and GVHD patients compared to allo-HSCT and healthy patients. Both GDF-15 and suPAR concentrations were linked to EASIX at day 100 and last follow-up. SuPAR was associated with creatinine and platelets at day 100 and last follow-up, while GDF-15 was associated only with platelets, suggesting that laboratory values do not drive EASIX. SuPAR, but not GDF-15, was related to soluble C5b-9 levels, a sign of increased HSCT-TMA risk. Our study shows for the first time that suPAR and GDF-15 indicate endothelial damage in allo-HSCT recipients. Rigorous validation of these biomarkers in many cohorts may provide utility for their usefulness in identifying and stratifying allo-HSCT recipients with endothelial cell impairment.

Real-life Experience With Rituximab-CHOP Every 21 or 14 Days in Primary Mediastinal Large B-cell Lymphoma.

BACKGROUND/AIM: Primary mediastinal large B-cell lymphoma (PMLBCL) is an aggressive B-cell non-Hodgkin lymphoma (NHL), whose prognosis has greatly improved since the incorporation of the anti-CD20 monoclonal antibody rituximab into current therapeutic regimens. Evidence, however, on the optimal time interval between consecutive chemoimmunotherapy (CIT) cycles is still scarce. This study aimed to evaluate the efficacy outcomes of the more commonly administered 3-weekly regimens to the biweekly ones in a PMLBCL patients' population, who were mostly treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone every 21 days (R-CHOP-21) or R-CHOP-14. PATIENTS AND METHODS: We retrospectively studied our cohort of consecutively treated PMLBCL patients, focusing on their treatment density, in order to determine possible differences in treatment outcomes. RESULTS: CIT, in the form of both R-CHOP-21 as well as R-CHOP-14 (or similar regimens), is highly active in PMLBCL, with low rates of early treatment failure. In our cohort of patients, R-CHOP-14 did not result in a meaningful improvement of freedom from progression (FFP) or overall survival (OS). CONCLUSION: Both R-CHOP-14 and R-CHOP-21 are probably equally effective in PMLBCL, yet further, prospective, randomized studies are warranted to clarify whether dose-dense regimens can be associated with better disease control and long-term results.

Identification of Very Low-Risk Subgroups of Patients with Primary Mediastinal Large B-Cell Lymphoma Treated with R-CHOP.

BACKGROUND: R-CHOP can cure approximately 75% of patients with primary mediastinal large B-cell lymphoma (PMLBCL), but prognostic factors have not been sufficiently evaluated yet. R-da- EPOCH is potentially more effective but also more toxic than R-CHOP. Reliable prognostic classification is needed to guide treatment decisions. MATERIALS AND METHODS: We analyzed the impact of clinical prognostic factors on the outcome of 332 PMLBCL patients ≤65 years treated with R-CHOP ± radiotherapy in a multicenter setting in Greece and Cyprus. RESULTS: With a median follow-up of 69 months, 5-year freedom from progression (FFP) was 78% and 5-year lymphoma specific survival (LSS) was 89%. On multivariate analysis, extranodal involvement (E/IV) and lactate dehydrogenase (LDH) ≥2 times upper limit of normal (model A) were significantly associated with FFP; E/IV and bulky disease (model B) were associated with LSS. Both models performed better than the International Prognostic Index (IPI) and the age-adjusted IPI by Harrel's C rank parameter and Akaike information criterion. Both models A and B defined high-risk subgroups (13%-27% of patients [pts]) with approximately 19%-23% lymphoma-related mortality. They also defined subgroups composing approximately one-fourth or one-half of the patients, with 11% risk of failure and only 1% or 4% 5-year lymphoma-related mortality. CONCLUSION: The combination of E/IV with either bulky disease or LDH ≥2 times upper limit of normal defined high-risk but not very-high-risk subgroups. More importantly, their absence defined subgroups comprising approximately one-fourth or one-half of the pts, with 11% risk of failure and minimal lymphoma-related mortality, who may not need more intensive treatment such as R-da-EPOCH. IMPLICATIONS FOR PRACTICE: By analyzing the impact of baseline clinical characteristics on outcomes of a large cohort of patients with primary mediastinal large B-cell lymphoma homogeneously treated with R-CHOP with or without radiotherapy, we developed novel prognostic indices which can aid in deciding which patients can be adequately treated with R-CHOP and do not need more intensive regimens such as R-da-EPOCH. The new indices consist of objectively determined characteristics (extranodal disease or stage IV, bulky disease, and markedly elevated serum lactate dehydrogenase), which are readily available from standard initial staging procedures and offer better discrimination compared with established risk scores (International Prognostic Index [IPI] and age-adjusted IPI).

Pomalidomide Plus Low-Dose Dexamethasone in Relapsed/Refractory Multiple Myeloma Patients: Results of the Real-World "POWERFUL" Study.

The "POWERFUL" multicenter, retrospective, and prospective study investigated the effectiveness of pomalidomide plus low-dose dexamethasone (POM/LoDex) therapy in relapsed/refractory multiple myeloma in routine care in Greece. Ninety-nine eligible adult patients treated with POM/LoDex according to the approved label after having received ≥2 prior therapies, including lenalidomide and bortezomib, were consecutively enrolled between 16 November 2017 and 21 February 2019 in 18 hematology departments. Fifty patients (50.5%) started POM/LoDex as third-line treatment. During the treatment period (median: 8.3 months; range: 0.3-47.6 months), the median POM dose was 4 mg/day, and 31.3% of the patients received additional antimyeloma agents. The overall response rate was 32.3%. During a median follow-up period of 13.8 months (Kaplan-Meier estimate), the median progression-free survival (PFS) was 10.5 months (95% CI: 7.4-14.4). The PFS was not significantly different between patients receiving POM/LoDex in the third versus later line of therapy, nor between patients receiving concomitant antimyeloma therapy versus POM/LoDEx doublet. During the prospective safety data collection period (median: 7.6 months) among patients with prospective follow-up (N = 75), POM-related adverse event incidence rate was 42.7% (serious: 18.7%; grade ≥ 3 hematological POM-related adverse events: 8.0%). Only neutropenia (13.3%) was reported at a frequency ≥10%. In conclusion, in this real-world study, POM/LoDex displayed a long PFS with no new safety signals emerging.

Real-life experience with the combination of polatuzumab vedotin, rituximab, and bendamustine in aggressive B-cell lymphomas.

Transplant-ineligible relapsed/refractory (rr) diffuse large B-cell lymphoma (DLBCL) patients represent an unmet medical need. Polatuzumab vedotin (Pola), an anti-CD79b antibody-drug-conjugate (ADG), with bendamustine- rituximab(BR) has recently gained approval for these patients, both in the USA and Europe, based on the GO29365 phase IIb trial. Real-life data with Pola are extremely limited. We report the outcomes of 61 Greek patients, who received Pola-(B)R mainly within a compassionate use program. Treatment was given for up to six 21-day cycles. Bendamustine was omitted in three cases due to previous short-lived responses. Fourty-nine rrDLBCL(efficacy cohort-EC) and 58 rr aggressive B-NHL (safety cohort-SC) patients received at least 1 Pola-BR cycle. Twenty-one (43%) patients of the EC responded with 12/49 (25%) CR and 9/49 (18%) PR as best response. Median progression-free survival, overall survival and duration of response were 4.0, 8.5, and 8.5 months respectively, while 55% of patients experienced a grade ≥3 adverse event, mainly hematologic. Treatment discontinuations and death during treatment were mainly due to disease progression. Twenty-two (41%) patients received further treatment; 11/22 are still alive, including one after CAR-T cells, and two after stem cell transplantation. Our data confirm that Pola-BR is a promising treatment for rrDLBCL patients, inducing an adequate response rate with acceptable toxicity. Pola-BR could be used as bridging therapy before further consolidative treatments.

Positron emission tomography after response to rituximab-CHOP in primary mediastinal large B-cell lymphoma: impact on outcomes and radiotherapy strategies.

End-of-treatment (EoT) PET/CT is used as a guide to omit radiotherapy (RT) patients with primary mediastinal large B-cell lymphoma (PMBCL). We present the mature and extended results of a retrospective study evaluating the prognostic significance of EoT-PET/CT after adequate response to R-CHOP. Among 231 consecutive PMLBCL patients, 182 underwent EoT-PET/CT and were evaluated according to the Deauville 5-point scale (D5PS) criteria. Freedom from progression (FFP) was measured from the time of PET/CT examination. Among 182 patients, 72 (40%) had D5PS score 1 (D5PSS-1), 33 (18%) had 2, 28 (15%) had 3, 29 (16%) had 4, and 20 (11%) had 5. The 5-year FFP was 97, 94, 92, 82, and 44% for D5PSS-1, D5PSS-2, D5PSS-3, D5PSS-4, and D5PSS-5, respectively. Among 105 patients with unequivocally negative PET/CT (D5PSS-1/D5PSS-2), 49 (47%) received RT (median dose 3420 cGy) and 56 (53%) did not with relapses in 0/49 vs. 4/56 patients (2 mediastinum and 2 isolated CNS relapses).The 5-year FFP for those who received RT or not was 100% versus 96%, when isolated CNS relapses were censored (p = 0.159). Among D5PSS-3 patients (27/28 irradiated-median dose 3600 cGy), the 5-year FFP was 92%. The 5-year FFP for D5PSS-4 and D5PSS-5 was 82 and 44%; 44/49 patients received RT (median dose 4000 and 4400 cGy for D5PSS-4 and D5PSS-5). Our study supports the omission of RT in a sizeable fraction of PET/CT-negative patients and definitely discourages salvage chemotherapy and ASCT in patients with PMLBCL who conventionally respond to R-CHOP, solely based on PET/CT positivity in the absence of documented progressive or multifocal disease. The persistence of positive PET/CT with D5PSS < 5 after consolidative RT should not trigger the initiation of further salvage chemotherapy in the absence of conventionally defined PD.

The Growth Differentiation Factor-15 (GDF-15) levels are increased in patients with compound heterozygous sickle cell and beta-thalassemia (HbS/ßthal), correlate with markers of hemolysis, iron burden, coagulation, endothelial dysfunction and pulmonary hypertension.

The clinical manifestations of Sickle Cell Disease (SCD) include episodes of vascular occlusion, chronic hemolytic anemia and frequent infections. GDF-15, a multifactorial cytokine, is a member of the transforming growth factor- superfamily. Expression of the GDF-15 gene in cardiomyocytes, vascular smooth muscle cells, and endothelial cells is strongly upregulated in response to oxidative stress, inflammation and tissue injury, while high levels of serum GDF-15 associate with ineffective erythropoiesis and may reflect a certain type of bone marrow stress or erythroblast apoptosis. In this context we aimed to evaluate GDF-15 levels in 89 patients with HbS/ßthal at steady phase and in 20 apparently healthy individuals, and correlate with clinical features of the disease and markers of hemolysis, iron burden, inflammation, coagulation and endothelial dysfunction. We found that: GDF-15 levels were elevated in patients with HbS/ßthal compared to controls (1980.7 ±â€¯159.8 vs 665.4 ±â€¯50.9 pg/mL, p < 0.0001) and correlated significantly with LDH (p < 0.001), Hepcidin-25/Ferritin molar ratio (p = 0.002), vWF:antigen (p < 0.05), HbA% (p < 0.001) and Mean Pulmonary Artery Pressure (p < 0.001). These findings demonstrate for first time an important multifactorial role of GDF-15 in patients with HbS/ßthal, however, prior to its clinical usefulness, this biomarker must undergo through rigorous validation in multiple cohorts.

PlGF and sFlt-1 levels in patients with non-transfusion-dependent thalassemia: Correlations with markers of iron burden and endothelial dysfunction.

BACKGROUND: Levels of the angiogenic cytokines placental growth factor (PlGF) and soluble Fms-like tyrosine kinase-1 (sFlt-1) and the angiogenic balance, expressed by sFlt-1/PlGF ratio, are perturbed in sickle-cell disease and iron overload, but they have not been evaluated in non-transfusion-dependent thalassemia (NTDT). PATIENTS AND METHODS: We measured levels of PlGF, sFlt-1 and vWF:antigen in patients with NTDT of beta-thalassemia genotype, and correlated them with erythrocytic indices and markers of iron overload, inflammation, and tissue hypoxia. Thirty-four NTDT patients with mean hemoglobin level of 8.4 g/dL were included in the study along with 20 apparently healthy individuals who served as controls. RESULTS: Ferritin, LDH, and hs-CRP were higher in patients as compared to controls. We found significant differences between patients and controls in regard to levels of PlGF (52.2 vs 17.2 pg/mL, P < .001), sFlt-1/PlGF (2 vs 4.7, P < .001), and vWF:antigen (88 vs 77.1 IU/dL, P < .01). There was a strong correlation of ferritin with PlGF (r = .653, P < .001) and with vWF:antigen (r = .503, P = .003). CONCLUSIONS: In this study, we demonstrated an association between increased PlGF and iron overload and the degree of tissue hypoxia in patients with NTDT. High vWF:antigen expressing endothelial damage may be associated with specific NTDT comorbidities.

Assessment of serum bioactive hepcidin-25, soluble transferrin receptor and their ratio in predialysis patients: Correlation with the response to intravenous ferric carboxymaltose.

BACKGROUND: No reliable biomarker exists to predict responsiveness to intravenous (IV) iron (Fe) in iron deficient patients with CKD. We aimed to investigate the clinical value of bioactive Hepcidin-25 and soluble Transferrin Receptor (sTfR) levels in predialysis patients. PATIENTS AND METHODS: In this prospective study 78 stable stage III-IV CKD predialysis patients with (responders) (40 patients) and without (non-responders) (38 patients) adequate erythropoiesis after IV administration of ferric-carboxymaltose (FCM). Patients were divided in two groups according to their response to IV administration of ferric-carboxymaltose (FCM). Along with measurements of common hematologic and blood chemistry parameters, determinations of sTfR and bioactive Hepcidin-25 were performed. RESULTS: Hepcidin-25 levels were lower in the responders (p=0.025), while sTfR and sTfR/Hepcidin-25 ratio were higher (p<0.01 and p=0.002 respectively). Diagnostic efficacy indicated cut off point of 1.49 for Hepcidin-25 had sensitivity 84% and specificity 48%, while cut off point of 1.21 for sTfR/Hepcidin-25 ratio had sensitivity 82% and specificity 52% to predict correctly response to iron supplementation therapy. Furthermore, log sTfR/Hepcidin-25 correlated negatively with hs-CRP (p=0.005) and IL-6 (p<0.04) in non-responders, while such correlations were not found in responders (p>0.05). CONCLUSIONS: These results suggest that lower Hepcidin-25, as well as higher sTfR and sTfR/Hepcidin-25 ratio were significant predictors of favorable hemoglobin response within a month after IV administration of FCM in patients with CKD. Further experiments and clinical studies in other groups of patients are needed to better elucidate the role of Hepcidin-25 and sTfR/Hepcidin-25 ratio as predictors of response to intravenous iron administration.

Correlation of Fc-γ RIIA polymorphisms with latent Epstein-Barr virus infection and latent membrane protein 1 expression in patients with low grade B-cell lymphomas.

Fc-γ RIIA (CD32), a member of the family of Fc-γ receptors, participates in the phagocytosis of bound to antibody antigens. The effectiveness of this function varies for its several haplotypes, and it participates in the pathogenesis of viral infections, according to recent studies. The genetic locus of Fc-γ RIIA consists of two allelic genes: 131-Arg (R131) and 131-His (H131). Our aim was to correlate Fc-γ RIIA polymorphisms, by studying the prevalence of each allele using PCR-RFLPs (polymerase chain reaction-restriction fragment length polymorphisms), with latent Epstein-Barr virus (EBV) infection and the expression of latent membrane protein 1 (LMP1) in 40 patients with leukemic low grade B-cell lymphomas. R131 was found in 84.2% of EBV-positive patients, but only in 28.5% of EBV-negative patients (p = 0.001). A similar correlation was found for R131 and LMP1 expression (84.6% vs. 28.5%) (p = 0.002). Our results support the hypothesis that Fc-γ RIIA polymorphisms are a genetic risk factor for latent EBV infection and the expression of its oncogenic latency proteins.

Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone with or without radiotherapy in primary mediastinal large B-cell lymphoma: the emerging standard of care.

UNLABELLED: More aggressive treatment approaches (methotrexate, cytarabine, cyclophosphamide, vincristine, prednisone, and bleomycin [the MACOP-B regimen] or consolidation with high-dose therapy and autologous stem cell transplantation) have been considered to be superior to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) in patients with primary mediastinal large B-cell lymphoma (PMLBCL). Rituximab-CHOP (R-CHOP) is the standard of care for diffuse large B-cell lymphoma, whereas efficacy in PMLBCL has not been adequately confirmed. PATIENT AND METHODS: Seventy-six consecutive PMLBCL patients who received R-CHOP with or without radiotherapy (RT) were compared with 45 consecutive historical controls treated with CHOP with or without RT. Baseline characteristics of the two groups were balanced. RESULTS: The rate of early treatment failure was much lower with R-CHOP with or without RT (9% versus 30%; p = .004). The 5-year freedom from progression rate after R-CHOP with or without RT was 81%, versus 48% for CHOP with or without RT (p < .0001). The 5-year event-free survival rates were 80% and 47% (p < .0001) and the 5-year overall and lymphoma-specific survival rates were 89% and 69% (p = .003) and 91% and 69% (p = .001), respectively, with only seven of 76 lymphoma-related deaths. Among R-CHOP responders, 52 of 68 received RT. CONCLUSIONS: Based on these results, most patients with PMLBCL appear to be cured by R-CHOP in 21-day cycles with or without RT, which could be the current standard of care. Therefore, the need for more aggressive treatment strategies is questionable unless high-risk patients are adequately defined. Further studies are required to establish the precise role of RT.

Acute lymphoplasmacytoid dendritic cell (DC2) leukemia: results from the Hellenic Dendritic Cell Leukemia Study Group.

We present a cohort of 22 patients with type 2 dendritic cell (DC2) acute leukemia (or blastic plasmacytoid dendritic cell neoplasm-BPDCN, as it has been recently named), diagnosed in Greece over the past 12-year period, according to the main clinical and immunophenotypic features of this entity. Four additional cases are discussed, classified as leukemia of ambiguous lineage (LAL), because of the simultaneous detection of a CD56 negative DC2 population and of a second myeloid precursor cell population. The morphological features and cytogenetic findings of the typical BPDCN cases were similar to those previously described. Acute lymphoblastic leukemia-type chemotherapeutic regimens were more efficient in controlling the disease. Immunophenotyping of typical BPDCN cases revealed CD4(+), CD56(+), HLA-DR(+) and CD123(bright) neoplastic cells, in the absence of major B-, T- and myeloid-associated markers, while the phenotype of the four cases characterized as LAL highlights the risk of misdiagnosis. Based on our experience, we propose a flow cytometric algorithmic approach for the distinction of typical BPDCN from certain types of acute myeloid leukemia, but also for the identification of acute myeloid leukemia, admixed with CD56 negative DC2 cells, which could be misdiagnosed as BPDCN.

First observation of Hb Taybe [Codons 38/39 (-Acc) Thr-->0 (alpha1)] in Greece: clinical and hematological findings in patients with co-inherited alpha+-thalassemia mutations.

This report describes four unrelated Greek patients (one child and three adults) who all had an atypical thalassemia intermedia phenotype, characterized by chronic moderate anemia with mild hemolysis in some cases, and the absence of abnormal hemoglobin (Hb) fractions. DNA analysis identified the inheritance of common alpha(+)-thalassemia (alpha(+)-thal) mutations in trans to an in-frame 3 bp deletion at codons 38/39 (-ACC) on the alpha1-globin gene, previously described as Hb Taybe. Hematological findings in the parents of three of the Hb Taybe carrier cases, together with a fourth unrelated carrier, are also presented. These cases represent the first observation of Hb Taybe in the Greek population, as to date, it has only been observed in Israeli-Arab families. With the exception of one patient and his mother who both originate from Corfu, all our cases come from the Greek island of Crete.

Pure infradiaphragmatic Hodgkin's lymphoma. Clinical features, prognostic factor and comparison with supradiaphragmatic disease.

BACKGROUND AND OBJECTIVES: Pure infradiaphragmatic Hodgkin's lymphoma (HL) is a rare disease. The prognostic impact of a purely infradiaphragmatic localization of this lymphoma is controversial. We aimed to evaluate the baseline clinicopathologic features, prognostic factors and outcome of a large series of consecutive patients with pure infradiaphragmatic HL. DESIGN AND METHODS: We analyzed 131 patients with clinical stage I/II infradiaphragmatic HL treated with ABVD or equivalent regimens with or without radiotherapy, and compared 54 of them with 444 patients with pure supradiaphragmatic disease, who were treated at the same center. RESULTS: Older age, clinical stage II (borderline), involvement of > or =3 sites, lymphocyte predominant histology, elevated serum beta2-microglobulin and higher International Prognostic Score were more frequent in patients with infradiaphragmatic disease than in those with supradiaphragmatic disease, while nodular sclerosis was less frequent. The complete remission rate was 100%, 97% and 82% for stages I, IIA and IIB, respectively. Only B-symptoms independently predicted for inferior failure-free survival, while inferior overall survival was independently associated with the involvement of > or =3 sites. At 10 years failure-free survival was 82+/-6% (vs. 85+/-2% for patients with supradiaphragmatic disease, p=0.45), overall survival was 74+/-8% (vs. 91+/-2%, p=0.0006), and disease-specific survival 87+/-5% (vs. 94+/-1%, p=0.04). In multivariate analysis the differences between infradiaphragmatic and supradiaphragmatic disease were obscured by older age and B-symptoms. INTERPRETATION AND CONCLUSIONS: Pure infradiaphragmatic HL presents with distinct clinicopathologic characteristics. The previously reported poorer outcome may be explained by the unfavorable profile of the patients rather than the infradiaphragmatic presentation per se. Patients with stage IIB disease should probably be classified as having advanced HL because of the unacceptable rate of primary refractory disease.

Pulsed cyclophosphamide, thalidomide and dexamethasone: an oral regimen for previously treated patients with multiple myeloma.

INTRODUCTION: Thalidomide is an oral agent with significant activity in one-third of patients with refractory myeloma. However, long-term continuous administration of thalidomide can be associated with significant side effects such as deep-vein thrombosis and peripheral neuropathy. Furthermore, it is not clear whether continuous administration of thalidomide is necessary for its antimyeloma effect. We performed a phase II study with a combination that was based on the intermittent administration of thalidomide. MATERIALS AND METHODS: A total of 53 patients with previously treated myeloma received cyclophosphamide 150 mg/m(2) p.o. every 12 h before meals on days 1-5, thalidomide 400 mg p.o. in the evening on days 1-5 and 14-18 and dexamethasone 20 mg/m(2) in the morning after breakfast on days 1-5 and 14-18 (CTD). The CTD combination was repeated every 28 days for three courses. Subsequently, responding patients were scheduled to receive maintenance treatment with monthly courses of CTD administered only for the first five days of each month. RESULTS: On an intention-to-treat basis, 32 patients (60%) achieved a partial response with a median time to response of 1.5 months. Among the 43 thalidomide-naïve patients, 67% responded. Toxicities were mild or moderate and the cumulative incidence of deep-vein thrombosis and peripheral neuropathy was 4 and 2%, respectively. The median time to progression for responding patients was 12 months and the median overall survival for all patients was 17.5 months. CONCLUSION: The oral, outpatient pulsed CTD regimen is associated with significant activity in patients with previously treated multiple myeloma. The incidence of deep-vein thrombosis and peripheral neuropathy appears to be lower than expected when thalidomide is being administered on a continuous basis.