[show abstract][hide abstract] ABSTRACT: As significant numbers of acute myeloid leukemia (AML) patients are still refractory to conventional therapies or experience relapse, immunotherapy using T-cells expressing chimeric antigen receptors (CARs) might represent a valid treatment option. AML cells frequently overexpress the myeloid antigens CD33 and CD123, for which specific CARs can be generated. However, CD33 is also expressed on normal hematopoietic stem/progenitors cells (HSPCs), and its targeting could potentially impair normal hematopoiesis. In contrast, CD123 is widely expressed by AML, while low expression is detected on HSPCs, making it a much more attractive target. In this study we describe the in vivo efficacy and safety of using cytokine-induced-killer (CIK) cells genetically modified to express anti-CD33 or anti-CD123 CAR to target AML. We show that both these modified T-cells are very efficient in reducing leukemia burden in vivo, but only the anti-CD123 CAR has limited killing on normal HSPCs, thus making it a very attractive immunotherapeutic tool for AML treatment.Leukemia accepted article preview online, 7 February 2014; doi:10.1038/leu.2014.62.
Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 02/2014; · 10.16 Impact Factor
[show abstract][hide abstract] ABSTRACT: Eighty-two children and adolescents who underwent allogeneic transplantation for acute lymphoblastic leukaemia in remission (period 2001-2011, median follow-up 4·9 years) had been assessed for minimal residual disease (MRD) by real-time quantitative polymerase chain reaction before and at 1, 3, 6, 9 and 12 months after transplantation. Five-year event-free survival (EFS) and cumulative incidence of relapse were 77·7% [standard error (SE) 5·7] and 11·4% (SE 4·4), respectively, for patients with pre-transplant MRD <1 × 10(-4) (68%), versus 30·8% (SE 9·1; P < 0·001) and 61·5% (SE 9·5; P < 0·001), respectively, for those with MRD ≥1 × 10(-4) (32%). Pre-transplant MRD ≥1 × 10(-4) was associated with a 9·2-fold risk of relapse [95% confidence interval (CI) 3·54-23·88; P < 0·001] compared with patients with MRD <1 × 10(-4) . Patients who received additional chemotherapy pre-transplant to reduce MRD had a fivefold reduction of risk of failure (hazard ratio 0·19, CI 0·05-0·70, P = 0·01). Patients who experienced MRD positivity post-transplant did not necessarily relapse (5-year EFS 40·3%, SE 9·3), but had a 2·5-fold risk of failure (CI 1·05-5·75; P = 0·04) if any MRD was detected in the first 100 d, which increased to 7·8-fold (CI 2·2-27·78; P = 0·002) if detected after 6 months. Anticipated immunosuppression-tapering according to MRD may have improved outcome, nevertheless all patients with post-transplant MRD ≥1 × 10(-3) ultimately relapsed, regardless of immunosuppression discontinuation or donor-lymphocyte-infusion. In conclusion, MRD before transplantation had the strongest impact on relapse and MRD positivity after transplantation, mostly if detected early and at low levels, did not necessarily imply relapse. Additional intensified chemotherapy and modulation of immunosuppression may reduce relapse risk and improve ultimate outcome.
British Journal of Haematology 02/2014; 164(3):396-408. · 4.94 Impact Factor
[show abstract][hide abstract] ABSTRACT: The ETV6-RUNX1 fusion gene, found in 25% of childhood acute lymphoblastic leukemia (ALL) cases, is acquired in utero but requires additional somatic mutations for overt leukemia. We used exome and low-coverage whole-genome sequencing to characterize secondary events associated with leukemic transformation. RAG-mediated deletions emerge as the dominant mutational process, characterized by recombination signal sequence motifs near breakpoints, incorporation of non-templated sequence at junctions, ∼30-fold enrichment at promoters and enhancers of genes actively transcribed in B cell development and an unexpectedly high ratio of recurrent to non-recurrent structural variants. Single-cell tracking shows that this mechanism is active throughout leukemic evolution, with evidence of localized clustering and reiterated deletions. Integration of data on point mutations and rearrangements identifies ATF7IP and MGA as two new tumor-suppressor genes in ALL. Thus, a remarkably parsimonious mutational process transforms ETV6-RUNX1-positive lymphoblasts, targeting the promoters, enhancers and first exons of genes that normally regulate B cell differentiation.
[show abstract][hide abstract] ABSTRACT: The outcome of high-risk (HR) Acute Lymphoblastic Leukemia (ALL) patients enrolled in AIEOP-BFM ALL 2000 study (NCT00613457) in Italy is described. Overall, 1999 Philadelphia negative ALL patients entered the study. HR criteria were: minimal residual disease (MRD) levels ≥10(-3) at day 78 (HR-MRD), no complete remission (no-CR) at day 33, t(4;11) translocation, Prednisone Poor Response (PPR). Treatment (2 years) included protocol I, 3 polychemotherapy blocks, delayed intensification (protocol IIx2 or IIIx3), cranial radiotherapy, maintenance. 312 HR patients (15.6% of the total) had 5-year event-free survival (EFS) and overall survival (OS) of 58.9%(SE 2.8) and 68.9%(2.6). In hierarchical order, EFS was 45.9%(4.4) in 132 HR-MRD patients, 41.2%(11.9) in 17 patients no-CR at day 33, 36.4%(14.5) in 11 patients with t(4;11), 74.0%(3.6) in 152 HR patients only for PPR. No statistically significant difference was found for disease-free survival (DFS) in patients with very high risk features (HR-MRD, no-CR at day 33, t(4;11) translocation), given HSCT (n=66) or chemotherapy only (n=88), after adjusting for waiting time to hematopoietic stem cell transplantation (HSCT) (5.7 months). Patients at HR only for PPR have favorable outcome. High risk MRD is associated with poor outcome despite intensive treatment and/or HSCT and may qualify for innovative therapies. The study is registered at the US National Institutes of Health website http://clinicaltrials.gov as "Combination Chemotherapy Based on Risk of Relapse in Treating Young Patients With Acute Lymphoblastic Leukaemia" with the protocol identification number NCT00613457.
[show abstract][hide abstract] ABSTRACT: Human bone marrow stromal cells (BMSCs, also known as bone marrow-derived “mesenchymal stem cells”) can establish the hematopoietic microenvironment within heterotopic ossicles generated by transplantation at non-skeletal sites. Here we show that non-mineralized cartilage pellets formed by hBMSCs ex vivo generate complete ossicles upon heterotopic transplantation in the absence of exogenous scaffolds. These ossicles display a remarkable degree of architectural fidelity, showing that an exogenous conductive scaffold is not an absolute requirement for bone formation by transplanted BMSCs. Marrow cavities within the ossicles include erythroid, myeloid and granulopoietic lineages, clonogenic hematopoietic progenitors and phenotypic HSCs, indicating that complete stem cell niches and hematopoiesis are established. hBMSCs (CD146+ adventitial reticular cells) are established in the heterotopic chimeric bone marrow through a unique process of endochondral bone marrow formation, distinct from physiological endochondral bone formation. In this process, chondrocytes remain viable and proliferate within the pellet, are released from cartilage, and convert into bone marrow stromal cells. Once explanted in secondary culture, these cells retain phenotype and properties of skeletal stem cells (“MSCs”), including the ability to form secondary cartilage pellets and secondary ossicles upon serial transplantation. Ex vivo, hBMSCs initially induced to form cartilage pellets can be reestablished in adherent culture and can modulate gene expression between cartilage and stromal cell phenotypes. These data show that so-called “cartilage differentiation” of BMSCs in vitro is a reversible phenomenon, which is actually reverted, in vivo, to the effect of generating stromal cells supporting the homing of hematopoietic stem cells and progenitors.
[show abstract][hide abstract] ABSTRACT: Childhood BCR-ABL1-positive B-cell precursor acute lymphoblastic leukemia (BCP-ALL) has an unfavorable outcome and is characterized by a high frequency of IKZF1 deletions. The prognostic value of IKZF1 deletions was evaluated in two cohorts of children with BCR-ABL1-positive BCP-ALL, before (pre-TKI) and after introduction of Imatinib (EsPhALL). IKZF1 deletions were found in 126/191 (66%) of the patients. In the pre-TKI cohort, IKZF1-deleted patients had an unfavorable outcome compared to wild-type patients (4-yr DFS 30.0±6.8% versus 57.5±9.4%, p=0.01). In the EsPhALL-cohort, the IKZF1 deletions were associated with an unfavorable prognosis in patients who were stratified by early clinical response in the good-risk arm (4-yr DFS 51.9±8.8% for IKZF1-deleted versus 78.6±13.9% for IKZF1 wild-type; p=0.03), even when treated with Imatinib (4-yr DFS 55.5±9.5% for IKZF1-deleted versus 75.0±21.7% for IKZF1 wild-type; p=0.05). In conclusion, IKZF1 deletions are predictive for a highly unfavorable outcome in children with BCR-ABL1-positive BCP-ALL irrespective the introduction of Imatinib. These results underscore the urgent need for alternative therapy for IKZF1-deleted BCR-ABL1-positive patients. In contrast, good-risk patients with IKZF1 wild-type responded remarkably well to Imatinib-containing regimens, thus providing a rationale to potentially avoid the use of hematopoietic stem cell transplantation in this subset of BCR-ABL1-positive children.
[show abstract][hide abstract] ABSTRACT: This phase I multicenter study was aimed at assessing the feasibility and safety of intravenous administration of third party-bone marrow derived Mesenchymal Stromal Cells (MSC) expanded in Platelet Lysate (PL) in 40 patients (15 children, 25 adults), experiencing steroid-resistant grade II-IV GvHD. Patients received a median of 3 MSC infusions after having failed conventional immunosuppressive therapy. A median cell dose of 1.5 x 10(6)/kg per infusion was administered. No acute toxicity was reported. Overall, 86 AE and SAE were reported in the study, most of which (72.1%) of infectious nature. Overall response rate, measured at 28 days following the last MSC injection, was 67.5%, with 27.5% complete response. The latter was significantly more frequent in patients exhibiting grade II GvHD as compared to higher grades (61.5% versus 11.1%, p=0.002), and was borderline significant in children as compared to adults (46.7 vs 16.0%, p=0.065). Overall survival at 1 and 2 years from the first MSC administration was 50.0% and 38.6%, with a median survival time of 1.1 years. In conclusion, MSC can be safely administered on top of conventional immunosuppression for steroid resistant GvHD treatment. Eudract Number 2008-007869-23, NCT01764100.
Biology of blood and marrow transplantation: journal of the American Society for Blood and Marrow Transplantation 12/2013; · 3.15 Impact Factor
[show abstract][hide abstract] ABSTRACT: The need for immunosuppression after allo/xenogenic mesenchymal stromal cell (MSC) transplantation is debated. This study compared the long-term effects of human (h) bone marrow MSC transplant in immunocompetent or immunosuppressed traumatic brain injured (TBI) mice. C57Bl/6 male mice were subjected to TBI or sham surgery followed 24h later by an intracerebroventricular infusion of phosphate buffer saline (PBS, control) or hMSC (150,000/5μl). Immunocompetent and cyclosporin-A immunosuppressed (CsA) mice were analyzed for gene expression at 72h, functional deficits and histological analysis at five weeks. Gene expression analysis showed the effectiveness of immunosuppression (INFγ reduction in CsA treated groups), with no evidence of early rejection (no changes of MHCII and CD86 in all TBI groups) and selective induction of Treg (increase of Foxp3) only in the TBI hMSC group. Five weeks after TBI, hMSC had comparable efficacy, with functional recovery (on both sensorimotor and cognitive deficits) and structural protection (contusion volume, vessel rescue effect, gliotic scar reduction, induction of neurogenesis) in immunosuppressed and immunocompetent mice. Therefore, long-term hMSC efficacy in TBI is not dependent on immunosuppressive treatment. These findings could have important clinical implication since immunosuppression in acute TBI patients may increase their risk of infection and not be tolerated.
[show abstract][hide abstract] ABSTRACT: Children with Down syndrome (DS) have an increased risk of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The prognostic factors and outcome of DS-ALL patients treated in contemporary protocols are uncertain. We studied 653 DS-ALL patients enrolled in 16 international trials from 1995-2004. Non-DS BCP-ALL patients from the DCOG and BFM were reference cohorts. DS-ALL patients had a higher 8-year cumulative incidence of relapse (26±2% vs. 15±1%; p<0.001) and 2-year treatment-related mortality (TRM) (7±1% vs. 2.0±<1%; p<0.0001) than non-DS patients, resulting in lower 8-year event-free survival (EFS) (64±2% vs. 81±2%; p<0.0001) and overall survival (74±2% vs. 89±1%; p<0.0001). Independent favorable prognostic factors include age<6 years (hazard ratio [HR]=0.58, p=0.002), white blood cell count (WBC) <10x10(9)/L (HR=0.60, p=0.005) and ETV6-RUNX1 (HR=0.14; p=0.006) for EFS, age (HR=0.48, p<0.001), ETV6-RUNX1 (HR 0.1, p=0.016) and high hyperdiploidy (HeH) (HR 0.29, p=0.04) for relapse-free survival. TRM was the major cause of death in ETV6-RUNX1 and HeH DS-ALLs. Thus while relapse is the main contributor to poorer survival in DS-ALL, infection-associated TRM was increased in all protocol elements, unrelated to treatment-phase or regimen. Future strategies to improve outcome in DS-ALL should include improved supportive care throughout therapy, and reduction of therapy in newly identified good-prognosis subgroups.
[show abstract][hide abstract] ABSTRACT: Focal segmental glomerulosclerosis (FSGS) is the most frequent acquired renal condition resulting in end stage kidney disease in children. We describe a cell therapy treatment with human allogeneic bone marrow mesenchymal stem cells (MSC) in a 13-year-old patient developing recurrent FSGS after renal transplantation, which was not responding to conventional therapy. This treatment relied on the following measurements:clinical and laboratory evaluation of renal function, proteome array, biopsy, short tandem repeat assay. Before MSC treatment, the patient needed weekly plasmapheresis to achieve proteinuria-to-creatininuria ratio below 5. After three MSC infusions without adverse events, the patient has a stable renal function and the proteinuria target was reached without plasmapheresis. In addition, some circulating inflammatory factors decreased and their levels were still low after one year. This is the first report of an MSC treatment in an FSGS patient. Even though different factors may have contributed to the clinical results, after MSC infusion a stable reduction in the serum level of several inflammatory factors has been registered and the patient does not need anymore plasmapheresis to keep proteinuria under control. In addition, this encouraging single case let us identify some putative efficacy biomarkers that could be of clinical interest in chronic kidney diseases.
[show abstract][hide abstract] ABSTRACT: In the context of Acute Myeloid Leukemia (AML) treatment, the interface between chemotherapy and immunotherapy is at present getting closer as never before. Scientific research is oriented in overcoming the main limits of actual chemotherapeutic regimens against AML, which still accounts for a considerable number of relapsed or resistant forms. A lot of investments have been done in the use of monoclonal antibodies (mAbs) and recently gene-modified immune cells have been considered as an alternative approach whenever chemotherapy fails to eradicate the disease. In this sense, AML is a potential suitable target for immunotherapeutic approaches, due to overexpression of several tumor antigens. Here we describe the state of the art of mAbs and cellular therapies employing engineered immune effectors, developed against specific AML antigens, in a window embracing preclinical research and translational studies to the clinical setting.