Ingunn Dybedal

A validated decision model for treating the anaemia of myelodysplastic syndromes with erythropoietin + granulocyte colony-stimulating factor: significant effects on quality of life

Summary. We have published previously a prototype of a decision model for anaemic patients with myelodysplastic syndromes (MDS), in which transfusion need and serum erythropoietin (S‐Epo) were used to define three groups with different probabilities of erythroid response to treatment with granulocyte colony‐stimulating factor (G‐CSF) + Epo. S‐Epo ≤ 500 U/l and a transfusion need of < 2 units/month predicted a high probability of response to treatment, S‐Epo > 500 U/l and ≥ 2 units/month for a poor response, whereas the presence of only one negative prognostic marker predicted an intermediate response. A total of 53 patients from a prospective study were included in our evaluation sample. Patients with good or intermediate probability of response were treated with G‐CSF + Epo. The overall response rate was 42% with 28·3% achieving a complete and 13·2% a partial response to treatment. The response rates were 61% and 14% in the good and intermediate predictive groups respectively. The model retained a significant predictive value in the evaluation sample (P < 0·001). Median duration of response was 23 months. Scores for global health and quality of life (QOL) were significantly lower in MDS patients than in a reference population, and fatigue and dyspnoea was significantly more prominent. Global QOL improved in patients responding to treatment (P = 0·01). The validated decision model defined a subgroup of patients with a response rate of 61% (95% confidence interval 48–74%) to treatment with G‐CSF + Epo. The majority of these patients have shown complete and durable responses.

Clonal expansion of T/NK-cells during tyrosine kinase inhibitor dasatinib therapy.

Dasatinib, a broad-spectrum tyrosine kinase inhibitor (TKI), predominantly targets BCR-ABL and SRC oncoproteins and also inhibits off-target kinases, which may result in unexpected drug responses. We identified 22 patients with marked lymphoproliferation in blood while on dasatinib therapy. Clonality and immunophenotype were analyzed and related clinical information was collected. An abrupt lymphocytosis (peak count range 4–20 × 109/l) with large granular lymphocyte (LGL) morphology was observed after a median of 3 months from the start of therapy and it persisted throughout the therapy. Fifteen patients had a cytotoxic T-cell and seven patients had an NK-cell phenotype. All T-cell expansions were clonal. Adverse effects, such as colitis and pleuritis, were common (18 of 22 patients) and were preceded by LGL lymphocytosis. Accumulation of identical cytotoxic T cells was also detected in pleural effusion and colon biopsy samples. Responses to dasatinib were good and included complete, unexpectedly long-lasting remissions in patients with advanced leukemia. In a phase II clinical study on 46 Philadelphia chromosome-positive acute lymphoblastic leukemia, patients with lymphocytosis had superior survival compared with patients without lymphocytosis. By inhibiting immunoregulatory kinases, dasatinib may induce a reversible state of aberrant immune reactivity associated with good clinical responses and a distinct adverse effect profile.

Erythropoietin and Granulocyte-Colony Stimulating Factor Treatment Associated With Improved Survival in Myelodysplastic Syndrome

PURPOSE To assess the effect of erythropoietin (EPO) plus granulocyte-colony stimulating factor (G-CSF) treatment on survival and leukemic transformation in myelodysplastic syndrome (MDS). PATIENTS AND METHODS We compared the long-term outcome of patients with MDS treated with EPO plus G-CSF (n = 121) with untreated patients (n = 237) with MDS using multivariate Cox regression with delayed entry, for the first time adjusting for all major prognostic variables (WHO classification, karyotype, cytopenias, level of transfusion-need, age, and sex). RESULTS The erythroid response rate to EPO plus G-CSF was 39%, and the median response duration 23 months (range, 3 to 116+). In the multivariate analysis, treatment was associated with improved overall survival (hazard ratio, 0.61; 95% CI, 0.44 to 0.83; P = .002). Interestingly, this positive association was primarily observed in patients requiring fewer than 2 units of RBCs per month. Treatment was not linked to the rate of acute myeloid leukemia in any defined subgroup, including patients with an increase of marrow blasts or an unfavorable karyotype. CONCLUSION The inherent risk of leukemic evolution in MDS makes the current investigation highly relevant, in light of the recent reports of potential negative effects of EPO treatment on outcome in patients with cancer. We conclude that treatment of anemia in MDS with EPO plus G-CSF may have a positive impact on outcome in patients with no or low transfusion need, while not affecting the risk of leukemic transformation.

Myelodysplastic Syndromes Are Propagated by Rare and Distinct Human Cancer Stem Cells In Vivo.

Evidence for distinct human cancer stem cells (CSCs) remains contentious and the degree to which different cancer cells contribute to propagating malignancies in patients remains unexplored. In low- to intermediate-risk myelodysplastic syndromes (MDS), we establish the existence of rare multipotent MDS stem cells (MDS-SCs), and their hierarchical relationship to lineage-restricted MDS progenitors. All identified somatically acquired genetic lesions were backtracked to distinct MDS-SCs, establishing their distinct MDS-propagating function in vivo. In isolated del(5q)-MDS, acquisition of del(5q) preceded diverse recurrent driver mutations. Sequential analysis in del(5q)-MDS revealed genetic evolution in MDS-SCs and MDS-progenitors prior to leukemic transformation. These findings provide definitive evidence for rare human MDS-SCs in vivo, with extensive implications for the targeting of the cells required and sufficient for MDS-propagation.

IFN-{gamma} Negatively Modulates Self-Renewal of Repopulating Human Hemopoietic Stem Cells.

Whereas multiple growth-promoting cytokines have been demonstrated to be involved in regulation of the hemopoietic stem cell (HSC) pool, the potential role of negative regulators is less clear. However, IFN-γ, if overexpressed, can mediate bone marrow suppression and has been directly implicated in a number of bone marrow failure syndromes, including graft-vs-host disease. Whether IFN-γ might directly affect the function of repopulating HSCs has, however, not been investigated. In the present study, we used in vitro conditions promoting self-renewing divisions of human HSCs to investigate the effect of IFN-γ on HSC maintenance and function. Although purified cord blood CD34+CD38− cells underwent cell divisions in the presence of IFN-γ, cycling HSCs exposed to IFN-γ in vitro were severely compromised in their ability to reconstitute long-term cultures in vitro and multilineage engraft NOD-SCID mice in vivo (>90% reduced activity in both HSC assays). In vitro studies suggested that IFN-γ accelerated differentiation of targeted human stem and progenitor cells. These results demonstrate that IFN-γ can negatively affect human HSC self-renewal.

Treatment of myelodysplastic syndromes with retinoic acid and 1α-hydroxy-vitamin D3 in combination with low-dose ara-C is not superior to ara-C alone. Results from a randomized study

Abstract: 63 evaluable patients with myelodysplastic syndromes (MDS) and 15 with acute myelogenous leukemia (AML) were randomized between low‐dose ara‐C (arm A) and low dose ara‐C in combination with 13‐cis‐retinoic acid (13‐CRA) and 1α‐hydroxy‐vitamin D3 (1α D3) (arm B). 69 patients were evaluable and 18 (26.1%) responded to therapy. The addition of 13‐CRA and 1α D3 had no positive influence on survival of the patients, remission rates or duration of remissions. 12/27 patients in arm A and 6/29 patients in arm B progressed from MDS to AML during the course of the study (p = 0.0527). Arm B gave significantly more side‐effects than arm A (p = 0.005). Therapeutic effects of 13‐CRA and 1α D3 on MDS is not supported by this study. However, an inhibiting effect on AML development in some MDS subgroups cannot be excluded.

Clinical effect of increasing doses of lenalidomide in high-risk myelodysplastic syndrome and acute myeloid leukemia with chromosome 5 abnormalities

Background Patients with chromosome 5 abnormalities and high-risk myelodysplastic syndromes or acute myeloid leukemia have a poor outcome. We hypothesized that increasing doses of lenalidomide may benefit this group of patients by inhibiting the tumor clone, as assessed by fluorescence in situ hybridization for del(5q31). Design and Methods Twenty-eight patients at diagnosis or with relapsed disease and not eligible for standard therapy (16 with acute myeloid leukemia, 12 with intermediate-risk 2 or high-risk myelodysplastic syndrome) were enrolled in this prospective phase II multicenter trial and treated with lenalidomide up to 30 mg daily for 16 weeks. Three patients had isolated del(5q), six had del(5q) plus one additional aberration, 14 had del(5q) and a complex karyotype, four had monosomy 5, and one had del(5q) identified by fluorescence in situ hybridization only. Results Major and minor cytogenetic responses, assessed by fluorescence in situ hybridization, were achieved in 5/26 (19%) and 2/26 (8%) patients, respectively, who received one or more dose of lenalidomide, while two patients achieved only a bone marrow response. Nine of all 26 patients (35%) and nine of the ten who completed the 16 weeks of trial responded to treatment. Using the International Working Group criteria for acute myeloid leukemia and myelodysplastic syndrome the overall response rate in treated patients with acute myeloid leukemia was 20% (3/15), while that for patients with myelodysplastic syndrome was 36% (4/11). Seven patients stopped therapy due to progressive disease and nine because of complications, most of which were disease-related. Response rates were similar in patients with isolated del(5q) and in those with additional aberrations. Interestingly, patients with TP53 mutations responded less well than those without mutations (2/13 versus 5/9, respectively; P=0.047). No responses were observed among 11 cases with deleterious TP53 mutations. Conclusions Our data support a role for higher doses of lenalidomide in poor prognosis patients with myelodysplastic syndrome and acute myeloid leukemia with deletion 5q. (Clinicaltrials.gov identifier NCT00761449).

Primary immunodeficiency diseases: Genomic approaches delineate heterogeneous Mendelian disorders

Background: Primary immunodeficiency diseases (PIDDs) are clinically and genetically heterogeneous disorders thus far associated with mutations in more than 300 genes. The clinical phenotypes derived from distinct genotypes can overlap. Genetic etiology can be a prognostic indicator of disease severity and can influence treatment decisions. Objective: We sought to investigate the ability of whole‐exome screening methods to detect disease‐causing variants in patients with PIDDs. Methods: Patients with PIDDs from 278 families from 22 countries were investigated by using whole‐exome sequencing. Computational copy number variant (CNV) prediction pipelines and an exome‐tiling chromosomal microarray were also applied to identify intragenic CNVs. Analytic approaches initially focused on 475 known or candidate PIDD genes but were nonexclusive and further tailored based on clinical data, family history, and immunophenotyping. Results: A likely molecular diagnosis was achieved in 110 (40%) unrelated probands. Clinical diagnosis was revised in about half (60/110) and management was directly altered in nearly a quarter (26/110) of families based on molecular findings. Twelve PIDD‐causing CNVs were detected, including 7 smaller than 30 Kb that would not have been detected with conventional diagnostic CNV arrays. Conclusion: This high‐throughput genomic approach enabled detection of disease‐related variants in unexpected genes; permitted detection of low‐grade constitutional, somatic, and revertant mosaicism; and provided evidence of a mutational burden in mixed PIDD immunophenotypes.

Impact of malignant stem cell burden on therapy outcome in newly diagnosed chronic myeloid leukemia patients

Chronic myeloid leukemia (CML) stem cells appear resistant to tyrosine kinase inhibitors (TKIs) in vitro, but their impact and drug sensitivity in vivo has not been systematically assessed. We prospectively analyzed the proportion of Philadelphia chromosome-positive leukemic stem cells (LSCs, Ph+CD34+CD38−) and progenitor cells (LPCs, Ph+CD34+CD38+) from 46 newly diagnosed CML patients both at the diagnosis and during imatinib or dasatinib therapy (ClinicalTrials.gov NCT00852566). At diagnosis, the proportion of LSCs varied markedly (1–100%) between individual patients with a significantly lower median value as compared with LPCs (79% vs 96%, respectively, P=0.0001). The LSC burden correlated with leukocyte count, spleen size, hemoglobin and blast percentage. A low initial LSC percentage was associated with less therapy-related hematological toxicity and superior cytogenetic and molecular responses. After initiation of TKI therapy, the LPCs and LSCs rapidly decreased in both therapy groups, but at 3 months time point the median LPC level was significantly lower in dasatinib group compared with imatinib patients (0.05% vs 0.68%, P=0.032). These data detail for the first time the prognostic significance of the LSC burden at diagnosis and show that in contrast to in vitro data, TKI therapy rapidly eradicates the majority of LSCs in patients.

No benefit from adding GM-CSF to induction chemotherapy in transforming myelodysplastic syndromes: better outcome in patients with less proliferative disease

In this prospective randomized multicenter trial 93 patients, median age 72 years, with RAEB-t (n=25) and myelodysplastic syndrome (MDS)-AML (n=68) were allocated to a standard induction chemotherapy regimen (TAD 2+7) with or without addition of granulocyte–macrophage-CSF (GM-CSF). The overall complete remission (CR) rate was 43% with no difference between the arms. Median survival times for all patients, CR patients, and non-CR patients were 280, 550, and 100 days, respectively, with no difference between the arms. Response rates were significantly better in patients with serum lactate dehydrogenase (S-LDH) levels ⩽9.5 μkat/l, bone marrow cellularity ⩽70%, and WBC counts <4.0 × 109/l, but S-LDH was the only variable independently associated with response by logistic regression analysis. Coxs regression analysis identified four significant prognostic factors for survival: bone marrow cellularity, S-LDH, cytogenetic risk group (International Prognostic Scoring System), and age. Only bone marrow cellularity (P=0.01) and S-LDH (P=0.0003) retained statistical significance in the log-rank test. Severe adverse events were significantly more common in the GM-TAD arm (P=0.01). Thus, addition of GM-CSF to chemotherapy showed no clinical benefit in terms of response but carried an increased risk for side effects. We present a clinically useful tool to predict response to chemotherapy and survival in elderly patients with transforming MDS, favoring patients with features of less proliferative disease.