Marc Berger

Imatinib plus Peginterferon Alfa-2a in Chronic Myeloid Leukemia

BACKGROUND Imatinib (400 mg daily) is considered the best initial therapy for patients with newly diagnosed chronic myeloid leukemia (CML) in the chronic phase. However, only a minority of patients treated with imatinib have a complete molecular remission. METHODS We randomly assigned 636 patients with untreated chronic-phase CML to receive imatinib alone at a dose of 400 mg daily, imatinib (400 mg daily) plus cytarabine (20 mg per square meter of body-surface area per day on days 15 through 28 of each 28-day cycle) or pegylated interferon (peginterferon) alfa-2a (90 μg weekly), or imatinib alone at a dose of 600 mg daily. Molecular and cytogenetic responses, time to treatment failure, overall and event-free survival, and adverse events were assessed. An analysis of molecular response at 12 months was planned. A superior molecular response was defined as a decrease in the ratio of transcripts of the tyrosine kinase gene BCR-ABL to transcripts of ABL of 0.01% or less, corresponding to a reduction of 4 log(10) units or more from the baseline level, as assessed by means of a real-time quantitative polymerase-chain-reaction assay. RESULTS At 12 months, the rates of cytogenetic response were similar among the four groups. The rate of a superior molecular response was significantly higher among patients receiving imatinib and peginterferon alfa-2a (30%) than among patients receiving 400 mg of imatinib alone (14%) (P=0.001). The rate was significantly higher among patients treated for more than 12 months than among those treated for 12 months or less. Gastrointestinal events were more frequent among patients receiving cytarabine, whereas rash and depression were more frequent among patients receiving peginterferon alfa-2a. CONCLUSIONS As compared with other treatments, the addition of peginterferon alfa-2a to imatinib therapy resulted in significantly higher rates of molecular response in patients with chronic-phase CML. (Funded by the French Ministry of Health and others; ClinicalTrials.gov number, NCT00219739.).

Uncontrolled-rate freezing and storage at –80°C, with only3.5-percent DMSO in cryoprotective solution for 109 autologous peripheral blood progenitor cell transplantations

BACKGROUND: Although controlled‐rate freezing and storage in liquid nitrogen are the standard procedure for peripheral blood progenitor cell (PBPC) cryopreserva‐tion, uncontrolled‐rate freezing and storage at –80°C have been reported.

Recommendations for the management of the haematological and onco-haematological aspects of Gaucher disease

Current knowledge of the haematological and onco‐haematological complications of type 1 Gaucher disease has been reviewed with the aim of identifying best clinical practice for treatment and disease management. It was concluded that: (i) Awareness of typical patterns of cytopenia can help clinicians distinguish haematological co‐morbidities. (ii) Red blood cell studies and complete iron metabolism evaluation at baseline are recommended. (iii) Haemoglobin levels defining anaemia should be raised and used in Gaucher disease treatment and monitoring. (iv) Surgeons should be aware of potential bleeding complications during surgery in Gaucher patients.

Mesenchymal content of fresh bone marrow: a proposed quality control method for cell therapy.

The scarcity of mesenchymal stem cells (MSC) in bone marrow (BM) has justified their ex vivo expansion before therapeutic use, but a method to evaluate the quality of initial mesenchymal content and track the modifications induced by graft processing has not yet been proposed. The aim of this study was to establish such a procedure. Flow cytometric and functional assay methods were modified to count CD45− CD14−/CD73+ subsets containing all MSC and used them to study BM from spongy bone (SB) and iliac crest aspirate (ICA). These methods detected the target subsets in all BM suspensions derived from SB (n = 154) and ICA, (n = 44) with a satisfactory correlation between immuno‐phenotyping and functional tests by low‐density plating. We noted a higher overall MSC frequency in SB cell suspensions but a lower plating efficiency of CD45− CD14−/CD73+ SB cells under standard culture conditions.

Molecular monitoring of tumor cell contamination in leukapheresis products from stage IV neuroblastoma patients before and after positive CD34 selection

BACKGROUND Autologous peripheral blood stem cell (PBSCs) are frequently used to reconstitute hematopoiesis following administration of megatherapy in children with advanced stage IV neuroblastoma. Some centers prefer the use of autografts enriched for CD34+ progenitor cells because the positive selection procedure is believed to reduce indirectly tumor cell contamination. PROCEDURES In this study, we monitored the efficiency of tumor cell purging following CD34 selection in PBSCs from seven patients with advanced neuroblastoma by using a highly sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) analysis, Amplification of tissues-specific mRNA transcript of tyrosine hydroxylase gene with nested primers enabled the detection of residual neuroblastoma cells with a sensitivity of one malignant-cell per 10(6) normals. RESULTS Using this method, contaminating tumor cells were detected in seven of nine leukapheresis products of the patients. After positive immunoselection of CD34+ cells on Ceprate column, only one of nine enriched stem cell fraction still contained tumor cells detectable by RT-PCR. In six cases, PCR positive PBSCs became PCR negative after selection. CONCLUSIONS We conclude that tumor cell contamination may be frequently detected in PBSC harvests of stage IV neuroblastoma patients by sensitive molecular analysis. The load of contaminating malignant cells might be reduced following CD34 selection.

A Review of Gaucher Disease Pathophysiology, Clinical Presentation and Treatments

Gaucher disease (GD, ORPHA355) is a rare, autosomal recessive genetic disorder. It is caused by a deficiency of the lysosomal enzyme, glucocerebrosidase, which leads to an accumulation of its substrate, glucosylceramide, in macrophages. In the general population, its incidence is approximately 1/40,000 to 1/60,000 births, rising to 1/800 in Ashkenazi Jews. The main cause of the cytopenia, splenomegaly, hepatomegaly, and bone lesions associated with the disease is considered to be the infiltration of the bone marrow, spleen, and liver by Gaucher cells. Type-1 Gaucher disease, which affects the majority of patients (90% in Europe and USA, but less in other regions), is characterized by effects on the viscera, whereas types 2 and 3 are also associated with neurological impairment, either severe in type 2 or variable in type 3. A diagnosis of GD can be confirmed by demonstrating the deficiency of acid glucocerebrosidase activity in leukocytes. Mutations in the GBA1 gene should be identified as they may be of prognostic value in some cases. Patients with type-1 GD—but also carriers of GBA1 mutation—have been found to be predisposed to developing Parkinson’s disease, and the risk of neoplasia associated with the disease is still subject to discussion. Disease-specific treatment consists of intravenous enzyme replacement therapy (ERT) using one of the currently available molecules (imiglucerase, velaglucerase, or taliglucerase). Orally administered inhibitors of glucosylceramide biosynthesis can also be used (miglustat or eliglustat).

Kinetics of hematopoietic progenitor cell release induced by G-CSF-alone in children with solid tumors and leukemias

The kinetics of peripheral blood progenitor cell (PBPC) release induced by G-CSF-alone at 10 μg/kg/day were monitored daily in 42 children with solid tumors and leukemias. Median 16- and 27-fold enrichment of circulating CD34+ cells and granulocyte–macrophage colony-forming units (CFU-GM) was noted with peak values occurring after the 4th or the 5th G-CSF dose. Individual values of PBCD34+ cell levels in patients with solid tumors were not significantly different after the 4th and after the 5th dose. The day-of-collection PBCD34+ cell concentration was related to the harvested CD34+ cell (P = 0.0001) and CFU-GM numbers (P = 0.0001). No correlations were found between PBPC enrichment and either patient age, body weight, diagnosis or pre-mobilization treatment duration. The median numbers of 1.1 × 106 CD34+ cells/kg and 28.1 × 104 CFU-GM/kg were derived from one patient’s blood volume processed. Nineteen patients received G-CSF-alone primed grafts and had successful engraftment. Our data indicate that in 88% of children a single standard leukapheresis is sufficient to obtain a minimum graft (2 × 106 CD34+ cell and/or 10 × 104 CGU-GM per kg) whether undertaken after the 4th dose of G-CSF or the 5th.

Large-volume leukapheresis procedure for peripheral blood progenitor cell collection in children weighing 15 kg or less: Efficacy and safety evaluation

BACKGROUND We update our experience on large-volume leukapheresis (LVL) in very small patients with malignancies. LVLs were performed with the aim of reducing the psychological impact of leukaphereses by reducing the number of procedures while collecting large numbers of cells. PROCEDURE Seventeen LVLs were performed using a Cobe Spectra separator in 14 patients weighing < or = 15 kg. A median of 3.8 patients blood volumes corresponding to 296 mL/kg (range, 202-565) of blood was processed per session of 190 minutes (120-279) duration. A femoral catheter was installed specially for collection for 88% LVL (vs. 35% for standard leukaphereses). A median volume of 16.9 mL/kg was collected with 5.4 x 10(8) MNC/kg (range, 0.6-16.3) and 8.2 x 10(6) CD34+ cells/kg (range, 1.3-31.7). RESULTS No signs of complications due to citrate toxicity were encountered. No hypotensive or hypothermic episodes were observed. Platelet counts were significantly diminished after each procedure (median: -59%). When the extracorporal line was not primed with red blood cells (RBC), the difference between pre-LVL and post-LVL hemoglobin levels was significant with a median 32 g/L decrease. CONCLUSIONS The LVL approach for peripheral blood progenitor cells (PBPC) collection in very small children may expose them to the risk of anemia and thrombocytopenia and an excess of special central line installation. The application of this technique in these patients should be reserved for special cases when a very large number of cells must be collected and should be performed by an experienced team.

Use of G‐CSF alone to mobilize peripheral blood stem cells for collection from children

Summary We report the data of 19 children with neuroblastoma (NB) or Ewings sarcoma (EW) who had peripheral blood stem cells (PBSCs) harvested after mobilization by: (1) cyclophosphamide (CY) + etoposide + G‐CSF, (2) CY+GM‐CSF, or (3) G‐CSF alon. There were no consistent differences in the number of PBSCs collected following these three different mobilization regimens as assessed by CFU‐GM. 17 patients were reinfused with PBSCs after myeloablative therapy and had successful haemopoietic recovery. These results show that in children with solid tumours such as NB or EW a sufficient number of PBSCs can be collected after G‐CSF alone, and that PBSCs collected following stimulation by G‐CSF alone are as effective in reconstituting haemopoiesis as those collected after mobilizing chemotherapy + HGFs.

Successful extracorporeal photochemotherapy for chronic graft-versus-host disease in pediatric patients.

A total of 254 extracorporeal photochemotherapy (ECP) procedures were performed in 8 children (median age 10 years; range 5-15) with extensive resistant chronic graft-versus-host disease (GVHD). ECP was carried out in the pediatric environment using a Cobe Spectra separator and UV-MATIC irradiator. A peripheral venous with a single-lumen permanent central catheter access (69% of ECP-apheresis) or a dual-lumen permanent central catheter access (26% of ECP-apheresis) were used preferentially. A median platelet decrease of 17% (0-71) (p = 0.0001) and median hemoglobin level decrease of 15 g/L (0-31)(p = 0.0001) were noted following each ECP-apheresis. However, none of the patients had profound thrombocytopenia or anemia. Two minor episodes of catheter related-bacteriemia (Staphylococcus aureus) were noted (2310 catheter-days). A negative correlation was found between lymphocyte collection efficacy (median = 38%) and pre ECP-apheresis lymphocyte count (r = 0.4, p = 0.00001). The median of 5 x 10(7) lymphocytes/kg (0.1-50.10(7)/kg) was irradiated in each procedure. All patients are alive and well, and 7/8 experienced a dramatic improvement in their cutaneous status. Liver and gut disease resolved completely in 4/6 and 5/5 patients, respectively. In all patients, a concomitant immunosuppressive therapy was stopped (5/8) or considerably reduced (3/8). Five patients with more than 2 years follow-up after discontinuation of ECP are in remission with no immunosuppression treatment. They have normal growth rates and normal school and sport activity. Our study shows that ECP is beneficial, well tolerated, and can be safely used for chronic GVHD treatment even in young children with low body weight and a poor performance status. We believe that having a dedicated pediatric environment together with an experienced, motivated, and specifically pediatric team is of crucial importance for improving patients acceptance of this long-term therapeutic program.