Biomedical subjects

Alessandro Rambaldi

Publications and source records attributed to Alessandro Rambaldi.

33 records · Page 2Linked to original sources

PubMed2004

Innovative cell-based therapies in onco-hematology: what are the clinical facts ?

BACKGROUND AND OBJECTIVES: One of the few measurable clinical results obtained by the use of somatic cells in onco hematology is the clear-cut effect donor leukocyte infusions (DLI) in patients with chronic myeloid leukemia (CML) who relapse after an allogeneic bone marrow transplantation (BMT). From then on much research has focused on the use of cells to treat different aspects of oncologic diseases from leukemia relapse to development in BMT recipients. METHODS AND INFORMATION SOURCES: In this review we critically and schematically summarize the cell-based therapies which have led to a clinical application and recapitulate the results. RESULTS AND STATE OF THE ART: Although the overall numbers of successfully treated patients is small, therapy has been shown to be safe and effective in a variety of clinical contexts in oncohematology. PERSPECTIVES: Preliminary data will have to be validated in well designed clinical trials with cells generated by reproducible methods and in accreditated structures working according to Good Manufacturing Practices (GMP).

CD40 Ligand↗

PubMed2004

Effect of alemtuzumab on neoplastic B cells.

BACKGROUND AND OBJECTIVES: The therapeutic antibody alemtuzumab is directed against the CD52 molecule and is used for the treatment of B-cell lymphocytic leukemia (B-CLL). We investigated the mechanism of action of this antibody in vitro against different neoplastic B cells and compared it to the anti-CD20 antibody rituximab. DESIGN AND METHODS: Complement-mediated cytotoxicity assays were performed on freshly isolated neoplastic cells using human serum as the source of complement. Antibody-dependent cellular cytotoxicity (ADCC) was evaluated by chromium release assays, using peripheral blood mononuclear cells as effector cells, before and after 2 days of culture with interleukin-2 (IL-2). RESULTS: Alemtuzumab lysed cells from the 23 B-CLL samples through complement activation (mean 80%) much more efficiently than rituximab did (mean 16%), presumably because of the higher expression of CD52 than of CD20. All other leukemic B cells, including 1 prolymphocytic leukemia, 2 hairy cell leukemias and 6 B-non Hodgkin's lymphomas were effective targets for both antibodies, with 88% and 85% mean lysis, respectively. Both CD52 and CD20 were highly expressed in these cells. In contrast, most neoplastic B cell samples were poorly lysed through ADCC using freshly isolated peripheral blood mononuclear cells as effectors with either monoclonal antibody and regardless of target antigen levels. ADCC was, however, significantly increased in all cases by culturing the effector cells with IL-2 for 2 days. INTERPRETATION AND CONCLUSIONS: Complement-mediated lysis is likely to be an important mechanism of action of alemtuzumab in B-CLL and combination with IL-2 may increase this antibody's efficacy through ADCC. Mature neoplastic B cells other than B-CLL express high levels of CD52 and are good targets for alemtuzumab-mediated cytotoxicity.

Aged↗

PubMed2003

Molecular histogenesis of posttransplantation lymphoproliferative disorders.

Posttransplantation lymphoproliferative disorders (PTLDs) represent a serious complication of solid organ transplantation. This study assessed the molecular histogenesis of 52 B-cell monoclonal PTLDs, including 12 polymorphic PTLDs (P-PTLDs), 36 diffuse large B-cell lymphomas (DLBCLs), and 4 Burkitt/Burkitt-like lymphomas (BL/BLLs). Somatic hypermutation (SHM) of immunoglobulin variable (IgV) genes documented that most monoclonal B-cell PTLDs (75% P-PTLDs, 91.3% DLBCLs, 100% BL/BLLs) derive from germinal center (GC)-experienced B cells. B-cell lymphoma 6 (BCL6) mutations occurred in 25% P-PTLDs, 60.6% DLBCLs, and 75.0% BL/BLLs. A first histogenetic category of PTLDs (31.2% DLBCLs) express the BCL6+/multiple myeloma oncogene-1 protein (MUM1-/+)/CD138- profile and mimic B cells experiencing the GC reaction, as also suggested by ongoing SHM in a fraction of these cases. A second subset of PTLDs (66.7% P-PTLDs and 31.2% DLBCLs) display the BCL6-/MUM1+/CD138- phenotype and mimic B cells that have concluded the GC reaction. A third histogenetic category of PTLDs (25.0% P-PTLDs and 31.2% DLBCLs) shows the BCL6-/MUM1+/CD138+ profile, consistent with preterminally differentiated post-GC B cells. Crippling mutations of IgV heavy chain (IgVH) and/or IgV light chain (IgVL) genes, leading to sterile rearrangements and normally preventing cell survival, occur in 4 DLBCLs and 1 BL/BLL that may have been rescued from apoptosis through expression of Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1). Overall, the histogenetic diversity of monoclonal B-cell PTLDs may help define biologically homogeneous categories of the disease.

Adolescent↗

PubMed2003

Long-term remission in mantle cell lymphoma following high-dose sequential chemotherapy and in vivo rituximab-purged stem cell autografting (R-HDS regimen).

Mantle cell lymphoma (MCL) is rarely cured with standard-dose chemotherapy. From January 1997 to February 2000, 28 previously untreated advanced-stage MCL patients younger than 61 years of age were treated at 9 Italian hematologic departments with 3 cycles of standard-dose debulking chemotherapy followed by a high-dose rituximab-supplemented sequence (R-HDS) including intravenous administration of high-dose cyclophosphamide, high-dose cytarabine, high-dose melphalan, and high-dose mitoxantrone plus melphalan. Study end points included toxicity, clinical and molecular response rates, long-term event-free survival (EFS), and overall survival (OS) rates, as well as the ability to harvest tumor-free peripheral blood stem cells. Optimal amounts of polymerase chain reaction-negative (PCR-negative) CD34+ cells were collected from all 20 informative patients. One patient died of toxicity. All 27 patients assessable for response achieved a complete response (CR), of which 24 remain in continuous complete remission (CCR) after a median follow-up of 35 months. Three patients had transient evidence of PCR-detectable disease in the bone marrow. The OS and EFS rates at 54 months were 89% and 79%, respectively. These results compare with the 42% OS rate and the 18% EFS rate observed in 35 age-matched historic controls treated with standard-dose chemotherapy at the participating centers. The use of rituximab in combination with high-dose chemotherapy represents a very effective in vivo purging method. The R-HDS regimen can be safely applied in a multicenter hematology setting and leads to long-term EFS and OS in the majority of patients with an otherwise incurable disease.

Adult↗

PubMed2003

Differential response of human acute myeloid leukemia cells to gemtuzumab ozogamicin in vitro: role of Chk1 and Chk2 phosphorylation and caspase 3.

Gemtuzumab ozogamicin (GO) is a humanized anti-CD33 antibody conjugated to the anticancer agent calicheamicin, approved for the treatment of CD33+-relapsed acute myeloid leukemia. We have investigated the effects of GO on 4 human myeloid leukemia lines of different French-American-British (FAB) types (KG-1, THP-1, HL-60, and NB-4), observing 3 different types of response. Exposure to GO (10-1000 ng/mL) induced G2 arrest (up to 80% of the cells) followed by apoptosis (45% of the cells) in HL-60 and NB-4 cells. By contrast, in THP-1 cells we observed a strong G2 arrest (up to 75% of the cells) with little apoptosis. Finally, the KG-1 line was completely resistant to the same concentrations of GO. These different responses did not correlate with the levels of expression of either CD33 or multiple-drug resistance proteins, although the higher cyclosporin A (CsA)-inhibitable efflux activity of KG-1 cells may play a role in the resistance of this line to the drug. We could show that Chk1 and Chk2 phosphorylation, but not p53 or p21 expression, correlated with G2 arrest, implicating the ataxia-telangiectasia mutated/ataxia-telangiectasia related (ATM/ATR)-Chk1/Chk2 pathway in the cell cycle response to GO. However, apoptosis was associated with caspase 3 activation. Freshly isolated acute myeloid leukemia (AML) cells showed patterns of response to GO in vitro similar to those observed with the cell lines, including phosphorylation of Chk2 and caspase 3 activation. Our results suggest that the different molecular pathways induced by the drug in vitro may reflect, at least in part, the variable response to GO obtained in vivo.

Acute Disease↗

PubMed2003

Rituximab-mediated antibody-dependent cellular cytotoxicity against neoplastic B cells is stimulated strongly by interleukin-2.

BACKGROUND AND OBJECTIVES: We analyzed the sensitivity of freshly isolated neoplastic B cells to rituximab-mediated antibody-dependent cellular cytotoxicity (ADCC), using different effector cells. DESIGN AND METHODS: ADCC was performed by 51Cr release assays in vitro, using peripheral blood mononuclear cells, IL-2-activated or expanded NK cells, neutrophils or macrophages as effector cells. B lymphoma lines and freshly isolated leukemic samples were used as targets. RESULTS: NK cells, but PMN or macrophages mediated rituximab dependent cellular cytotoxicity against two B lymphoma lines. Purified NK cells (95% CD56+/CD16+) reached 70% lysis at the highest E:T ratio. By contrast, all freshly isolated B leukemia or lymphoma cases, including 5 chronic lymphocytic leukemia, 1 B-prolymphocytic leukemia, 1 mantle cell lymphoma, 2 marginal zone lymhomas and 2 follicular lymphomas were poorly lysed by ADCC in the same conditions and regardless of CD20 expression levels, reaching a mean of 4% and 27% maximal lysis with PBMC or purified NK cells, respectively. Interestingly, short term IL-2 cultured PBMC, containing 10 % activated NK cells, as well as long-term expanded NK cells, containing 80-95% activated NK cells, became strong ADCC effector cells with rituximab and lysed all leukemic samples to a mean of 57% and 67% at the highest E:T ratio, respectively. INTERPRETATION AND CONCLUSIONS: Primary leukemic cells are more resistant than cell lines to rituximab- and NK cell-mediated ADCC but short-term exposure to IL-2 or long-term expansion of NK cells in vitro may provide effective tools to improve the therapeutic activity of rituximab.

Antibodies, Monoclonal↗

PubMed2002

Lymphomas occurring late after solid-organ transplantation: influence of treatment on the clinical outcome.

BACKGROUND: Posttransplant lymphoproliferative disorders (PTLDs) that occur late after solid-organ transplantation are usually a monoclonal proliferation frequently characterized by the lack of the Epstein-Barr virus genome in tumor cells. The clinical outcome and the best management for patients who present with late PTLDs still remain unclear. PATIENTS AND METHODS: Thirty patients who developed PTLDs more than 12 months (range 13-156) after heart, kidney, or liver transplantation were retrospectively evaluated. Median age was 36.7 years (range 1-70). Fifty-five percent of patients presented with advanced-stage (III-IV) lymphoma, 43% of patients presented with B symptoms, and 40% of patients showed extranodal involvement. Twenty-four cases (75%) were categorized as monoclonal monomorphic PTLD. RESULTS: Three patients died of progressive multiorgan failure before any treatment was initiated. Overall, 17 (63%) patients obtained a clinical response (14 patients had complete remission [CR] and 3 patients had partial remission [PR]). Eight (47%) patients are still alive and in CR, two (12%) patients died in CR, and seven (41%) patients relapsed. With a median follow-up of 6 months (range 0.5-42.8), the median overall survival was 6.2 months. Both clinical response and survival were significantly influenced by the treatment. Indeed, all patients treated for limited disease with surgery or radiotherapy in combination with modulation of immunosuppression obtained CR and are still alive and in CR. On the contrary, 33% of patients who received chemotherapy obtained a clinical response, whereas 15% of patients who received chemotherapy showed progressive disease and 50% of patients who received chemotherapy died of toxicity (infectious or multiorgan failure). CONCLUSIONS: We suggest that patients with late PTLDs and limited disease may benefit from local treatment. For patients who require chemotherapy, we suggest that it should be administered to minimize the risk of infection complications.

Adolescent↗

PubMed2002

A human immunodeficiency virus type 1 pol gene-derived sequence (cPPT/CTS) increases the efficiency of transduction of human nondividing monocytes and T lymphocytes by lentiviral vectors.

We have investigated the capacity of two human immunodeficiency virus type 1-derived lentivectors, differing in the presence of a 118-bp pol fragment containing the cPPT/CTS element, to transduce human normal primary cells of different hematopoietic lineages. Infection of resting monocytes with a high multiplicity of infection (MOI > 10) revealed that the lentivirus carrying the pol fragment (cPPT) is effective, transducing 75% of cells compared with 36% for the no-cPPT vector. Even at low MOIs (< or =1) the cPPT vector still shows a better transduction efficiency than the no-cPPT vector. Moreover, transduction does not require dendritic cell differentiation. In contrast, infection of nonactivated T lymphocytes showed that both vectors, tested at high MOIs, can transduce a small, although measurable, percentage of cells (up to 10%), which may correspond to G(1a) "activated" cells as detected by simultaneous staining of DNA and RNA, in our cultures in the presence of medium alone. Furthermore, we show that the sole addition of interleukin 2 or interleukin 15 represents a full proliferative signal under our conditions and permits high transduction efficiency (up to 30% with the cPPT vector and 15% with the no-cPPT vector). Still higher transduction of T lymphocytes can be achieved after stimulation with phytohemagglutinin and interleukin 2 (up to 78% with the cPPT vector vs. 42% with the no-cPPT vector). Finally, both viruses do not transduce either resting or proliferating tonsillar B lymphocytes.

B-Lymphocytes↗

PubMed2002

Bis-indols: a novel class of molecules enhancing the cytodifferentiating properties of retinoids in myeloid leukemia cells.

Enhancing the pharmacologic activity of all-trans retinoic acid (ATRA) is potentially useful in the management of acute promyelocytic leukemia (APL) and other types of myeloid leukemia. In this report, we identify a novel class of experimental agents selectively potentiating the cytodifferentiating activity of ATRA and synthetic retinoic acid receptor alpha agonists in APL and other myeloid leukemia cell lines. These agents have a bis-indolic structure (BISINDS), and ST1346 is the prototypical compound of the series. Gene-profiling experiments and determination of the level of expression of myeloid-associated markers indicate that ST1346 stimulates many aspects of the granulocytic maturation process set in motion by ATRA. Stimulation of the cytodifferentiating activity of ATRA by ST1346 enhances the efficacy of the retinoid in vivo, as demonstrated in the APL model of the severe combined immunodeficiency (SCID) mouse receiving transplants of NB4 cells. Although the molecular mechanisms underlying the ATRA-potentiating action of ST1346 and congeners have not been completely clarified, bis-indols are not ligands and do not exert any direct effect on the ATRA-dependent transactivation of nuclear receptors. However, ST1346 inhibits the down-regulation of cyclic adenosine monophosphate (cAMP)-dependent CREB transcriptional complexes and enhances the level of expression of signal transducers and activators of transcription-1 (STAT1), 2 putative molecular determinants of the differentiation process activated by ATRA in APL cells. More importantly, ST1346 relieves the down-regulation of Jun N-terminal kinases (JNK) afforded by ATRA. In addition, a specific JNK inhibitor blocks the enhancing effect of ST1346 on ATRA-induced maturation of NB4 cells. This demonstrates an important role for the mitogen-activated protein kinase in the molecular mechanisms underlying the pharmacologic activity of the bis-indol.

Antineoplastic Agents↗

PubMed2002

Monitoring of minimal residual disease after CHOP and rituximab in previously untreated patients with follicular lymphoma.

Minimal residual disease (MRD) following sequential administration of CHOP and rituximab was studied in previously untreated patients with follicular lymphoma. At diagnosis, the presence of Bcl-2/IgH-positive cells in the peripheral blood (PB) and/or bone marrow (BM) was demonstrated in all patients (n = 128) by polymerase chain reaction (PCR) analysis. Patients who achieved a clinical response following CHOP but remained PCR-positive were eligible for rituximab (375 mg/m(2) intravenously, weekly for 4 weeks). After CHOP, 57% achieved a complete response (CR), 37% a partial response (PR), and 6% were nonresponders (NR). At this stage, patients proving PCR-negative (n = 41) or failing to achieve a clinical response (n = 8) were excluded from rituximab treatment. Seventy-seven patients received rituximab and entered a scheduled MRD follow-up program. At the first molecular follow-up (+12 weeks), 59% had converted to PCR negativity in the BM and PB, with a further increase documented at the second control (+28 weeks) with 74% PCR negative. At the last molecular follow-up (+44 weeks), 63% of the patients remained PCR negative. At 3 years, the estimated overall survival of all patients is 95% (95% confidence interval [CI], 86-98). For patients achieving PCR-negative status following CHOP and therefore excluded from rituximab treatment, freedom from recurrence (FFR) was 52% (95% CI, 28-71). For patients treated with rituximab, a durable PCR-negative status was associated with a better clinical outcome since FFR was 57% (95% CI, 23-81) compared with 20% (95% CI, 4-46) in patients who never achieved or lost the molecular negativity (P <.001).

Adult↗

PubMed2002

Reduced-intensity conditioning followed by allografting of hematopoietic cells can produce clinical and molecular remissions in patients with poor-risk hematologic malignancies.

A reduced-intensity conditioning regimen was investigated in 45 patients with hematologic malignancies who were considered poor candidates for conventional myeloablative regimens. Median patient age was 49 years. Twenty-six patients previously failed autologous transplantation, and 18 patients had a refractory disease at the time of transplantation. In order to decrease nonrelapse mortality, and enhance the graft-versus-tumor effect, a program was designed in which a reduced conditioning with thiotepa, fludarabine, and cyclophosphamide was associated with programmed reinfusions of donor lymphocytes for patients without graft-versus-host disease (GVHD), not achieving clinical and molecular remission after transplantation. GVHD prophylaxis consisted of cyclosporine A and methotrexate. Seventeen patients received marrow cells and 28 received mobilized hematopoietic cells. All patients engrafted. The probability of grades II-IV and III-IV acute GVHD were 47% and 13%, respectively. The probability of nonrelapse mortality, progression-free survival, and overall survival were 13%, 57%, and 53%, respectively. Thirteen patients in complete remission had a polymerase chain reaction marker for minimal disease monitoring; 10 achieved molecular remission after transplantation. Nine patients received donor lymphocytes: one patient with mantle cell lymphoma had a minimal response, one patient with refractory anemia with excess of blasts in transformation achieved complete remission, and 7 patients did not respond. At a median follow-up of 385 days (range, 24 to 820 days), 25 patients (55%) were alive in complete remission. Although longer follow-up is needed to evaluate the long-term outcome, the study shows that this regimen is associated with a durable engraftment, has a low nonrelapse mortality rate, and can induce clinical and molecular remissions.

Adult↗

PubMed2002

Prolonged administration of all-trans retinoic acid in combination with intensive chemotherapy and G-CSF for adult acute myelogenous leukemia: single-centre pilot study in different risk groups.

INTRODUCTION: An exploratory trial was conducted to evaluate toxicity and potential therapeutic role of all trans-retinoic acid (ATRA) given long-term together with chemotherapy and G-CSF to adult patients with acute myelogenous leukemia (AML). MATERIALS AND METHODS: ATRA was administered orally at 45 mg/m(2)/day on days 1-14 and 25 mg/m(2)/day on days 15-28 of two standard cycles (idarubicin, etoposide, cytarabine, G-CSF) and of up to three high-dose courses (cytarabine, G-CSF). The results obtained in 19 patients enrolled in the ATRA trial were compared with those from 29 comparable cases treated with the same schedule without ATRA, according to patient risk class and an in vitro study. RESULTS: ATRA was administered for a median of 52 days to the patients selected for study who achieved a remission. ATRA-related toxicity was mostly non-severe apart from high incidence of headache in conjunction with high-dose cytarabine. Complete remission (CR) rate after cycle 1 (54%), kinetics of hematological recovery, postremission treatment realization, disease-free survival (DFS 37.5% at three years) and overall survival (30% at three years) were not different between ATRA-treated and untreated patients. The only significant prognostic factor was the patient risk class, as defined by cytogenetics and other clinical criteria: DFS rate was 57% at three years in standard-risk cases compared to only 19% in the high-risk group, with no influx by ATRA in either category. The in vitro study, in patients with a definite clinical response, failed to document any inhibitory or pro-apoptotic effect of ATRA on AML blast cells. CONCLUSION: As a consequence to these results, the pilot ATRA phase was closed. This study does not suggest a significant role for the present ATRA schedule as an adjunct to standard antileukemic therapy in adult AML.

Acute Disease↗

PubMed2002

Negative selection of peripheral blood stem cells to support a tandem autologous transplantation programme in multiple myeloma.

We recently described a two-step negative selection procedure whereby peripheral blood stem cells (PBSCs) were efficiently purged of contaminating neoplastic cells by a combination of monoclonal antibodies. Here, we report 60 newly diagnosed multiple myeloma (MM) patients treated with a double transplant programme and randomized to receive either unmanipulated or in vitro purged PBSCs. We demonstrated that this technique is feasible and safe without significant loss of either CD34+ or CD3+ cells. Haematological engraftment and immunological reconstitution were rapid without treatment-related mortality. Using polymerase chain reaction (PCR), we compared the level of minimal residual disease (MRD) in PBSC before and after in vitro purging and in vivo after transplant. A median of one tumour cell per 10(2) normal cells (range 10(1)-10(5)) was seen in the unmanipulated aphereses with a 3-4 log reduction after manipulation in vitro. However, despite this tumour debulking, all patients remained PCR positive in vivo. At 3 years, the estimated event-free survival was 40% in the control arm and 72% in the experimental arm (P = 0.05), whereas the estimated overall survival was 83% in both arms. This suggests that autologous transplantation using efficiently purged PBSCs can be performed safely, but confirms the need for innovative protocols for MRD eradication in vivo.

Adult↗

PubMed2002

Molecular characterization of a new recombination of the SIL/TAL-1 locus in a child with T-cell acute lymphoblastic leukaemia.

Deletions involving the SIL-TAL-1 locus are seen in 15% of T-acute lymphoblastic leukaemias (T-ALL). To date, seven deletions have been described, spreading over 90 kb of chromosome 1, fusing SIL to the TAL-1 gene and resulting in over expression of TAL-1. During the diagnostic screening of the TAL-1 deletion in 176 T-ALL patients, we identified one case showing a new SIL rearrangement. A novel fusion transcript was identified between the SIL exon 1a and an unknown sequence (633-cDNA). Polymerase chain reaction (PCR) screening of a human cDNA library confirmed the existence of this transcript. Using long-distance PCR on patient DNA, we obtained a genomic fragment containing SIL exon 1b, a portion of intron 1b, an unknown sequence and the 633 sequence. Using DNA from healthy donors, a partial genomic map of 633-DNA was found to be identical to the restriction map of the PCR fragment amplified from patient DNA. To define the chromosomal origin of 633-DNA, a YAC human genomic library was screened. Two clones containing 633-DNA were found, mapping to chromosomal region 1p32 and both contained SIL and TAL-1 sequences. By searching GenBank, we identified PAC RP1-18D14 which contains SIL, TAL-1 and 633-DNA, confirming this novel rearrangement as a new deletion of the SIL/TAL-1 locus.

Adolescent↗

PubMed2002

Phase I trial with escalating doses of idarubicin and multidrug resistance reversal by short-course cyclosporin A, sequential high-dose cytosine arabinoside, and granulocyte colony-stimulating factor for adult patients with refractory acute leukemia.

BACKGROUND AND OBJECTIVES: Patients with refractory acute myeloid or lymphoid leukemia (AML, ALL) were treated with a high-dose regimen comprising idarubicin (IDR) plus short-course cyclosporin A (CsA) as multidrug resistance type-1 (MDR1) blocking agent. The principal aim was to define the maximum tolerated dose (MTD) of IDR, which is reported to be a less MDR1-sensitive anthracycline. The short CsA infusion was patterned after the results of a previous in vitro study. DESIGN AND METHODS: This was a phase I trial, in which eligible patients received high-dose cytarabine (HDAC) 3 g/m(2)/bd on days 1, 2 and 8, 9, and IDR 12.5-20 mg/m(2)/d on days 3 and 10, with increments of 2.5 mg/m(2)/d from the baseline per treatment group. Intravenous CsA infusion started 4 hours before IDR and lasted 12 hours. Recombinant granulocyte colony-stimulating factor (G-CSF) was added from day 11. IDR MTD was evaluated through analysis of regimen-related toxicity (RRT). RESULTS: Eighteen patients were treated (16 AML, 2 ALL; MDR1+: 8/8 studied). Overall response rate was 61%. Toxicity was severe but manageable up to an IDR dose of 17.5 mg/m(2)/d, while grade 4 RRT developed with IDR 20 mg/m(2)/d. High-grade toxicity, not strictly regimen-related, was sometimes observed at lower IDR concentrations in patients with unresolved complications from prior extensive treatments. In keeping, the complete response (CR) rate was 92% (11/12) for patients with an ECOG performance score <2 compared to 0% (0/6) in the others (p=0.000). Apart from that, induction of markedly hypocellular, leukemia-free bone marrow on day 11 was associated with achievement of CR (13 evaluable: CR 8/10 vs 0/3, p=0.035). INTERPRETATION AND CONCLUSIONS: IDR at 17.5 mg/m(2)/d (x2) can be associated with short-course CsA and HDAC for the management of refractory acute leukemias. While this regimen could deserve testing in a larger phase II trial, to document activity in MDR1+ disease, it remains important to select the most suitable patients in order to avoid the occurrence of life-threatening cumulative toxicity.

Acute Disease↗