Francisco Bracho

Icatibant, a New Bradykinin-Receptor Antagonist, in Hereditary Angioedema

BACKGROUND Hereditary angioedema is characterized by recurrent attacks of angioedema of the skin, larynx, and gastrointestinal tract. Bradykinin is the key mediator of symptoms. Icatibant is a selective bradykinin B2 receptor antagonist. METHODS In two double-blind, randomized, multicenter trials, we evaluated the effect of icatibant in patients with hereditary angioedema presenting with cutaneous or abdominal attacks. In the For Angioedema Subcutaneous Treatment (FAST) 1 trial, patients received either icatibant or placebo; in FAST-2, patients received either icatibant or oral tranexamic acid, at a dose of 3 g daily for 2 days. Icatibant was given once, subcutaneously, at a dose of 30 mg. The primary end point was the median time to clinically significant relief of symptoms. RESULTS A total of 56 and 74 patients underwent randomization in the FAST-1 and FAST-2 trials, respectively. The primary end point was reached in 2.5 hours with icatibant versus 4.6 hours with placebo in the FAST-1 trial (P=0.14) and in 2.0 hours with icatibant versus 12.0 hours with tranexamic acid in the FAST-2 trial (P<0.001). In the FAST-1 study, 3 recipients of icatibant and 13 recipients of placebo needed treatment with rescue medication. The median time to first improvement of symptoms, as assessed by patients and by investigators, was significantly shorter with icatibant in both trials. No icatibant-related serious adverse events were reported. CONCLUSIONS In patients with hereditary angioedema having acute attacks, we found a significant benefit of icatibant as compared with tranexamic acid in one trial and a nonsignificant benefit of icatibant as compared with placebo in the other trial with regard to the primary end point. The early use of rescue medication may have obscured the benefit of icatibant in the placebo trial. (Funded by Jerini; ClinicalTrials.gov numbers, NCT00097695 and NCT00500656.)

Potential use of granulocyte colon-stimulating factor and granulocyte-macrophage colony-stimulating factor in neonates.

The immaturity of neonatal phagocytic immunity contributes to increased mortality during neonatal sepsis. Neonates have both quantitative and qualitative neutrophil defects with decreased bone marrow neutrophil storage pool (NSP) reserves, an inability to increase neutrophil production, and defective neutrophil functional activity. Neonates respond to overwhelming sepsis with depletion of the NSP and the development of peripheral neutropenia. The myelopoietic cytokines granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) have been documented to induce neutrophilia in neonatal animals and human infants, increase the NSP, and upregulate neutrophils for improved functional activity. Preclinical studies in neonatal rats demonstrate increased survival with prophylactic G-CSF during experimental group B streptococcal sepsis. In pilot phase l/ll human trials, G-CSF and GM-CSF were demonstrated to be both safe and well tolerated and to induce significant increases in absolute neutrophil count and NSP. Prophylactic GM-CSF in the very low birth weight neonate may reduce the incidence of nosocomial infections. Phase III trials are needed to further delineate the clinical usefulness of these myelopoietic cytokines in neonates with a high predisposition to sepsis.

A comparison of ex vivo expanded DCs derived from cord blood and mobilized adult peripheral blood plastic-adherent mononuclear cells: decreased alloreactivity of cord blood DCs *

BACKGROUND Cord blood (CB) has been used as an alternative source of transplantable allogeneic stem cells for a variety of malignant and non-malignant diseases. However, we have demonstrated delayed recovery of T- and B-cell function, and T-cell subsets post unrelated CB transplantation (UCBT), and deficiencies of CB mononuclear cells (MNC) in producing cytokines, including G-CSF, GM-CSF, M-CSF, IL-12, and IL-15. In this study we have investigated the ex vivo generation of DC from CB versus mobilized adult peripheral blood (APB) for later use as adoptive cellular immunotherapy. METHODS CB and APB-adherent MNC were cultured in serum-free media with GM-CSF IL-4, FLT-3 ligand, tumor growth factor-beta (TGF-beta), and tumor necrosis factor-alpha (TNF-alpha) for 7 days. Morphology, phenotype, immunohistochemistry, clonogenic activity, and alloreactivity in MLR were evaluated. RESULTS CB and APB monocyte-derived ex vivo expanded DC expressed similar DC markers CD83 (31.27+ 11.7% versus 34.0+ 5.2%, CB versus APB), CD1a (23.4+ 4.2% versus 27.6+ 6.3%), and CD80 (21.97+ 12.01% versus 27.7+ 5.95). Immunohistochemistry showed that cells with DC morphology expressed CDla but not CD14. Neither FLT-3 ligand nor TGF-fl enhanced DC expansion. Addition of 10% autologous plasma to CB cultures promoted greater cell survival and a 150% increase in CDla + /CD80+ cell recovery. CB DC were 62% as effective stimulators of adult allogeneic T-cels as APB DC (p < .05) in allogeneic MLR. DISCUSSION While phenotypically similar, CB and APB DC have differential potency in allogeneic MLR, which may account for the difference in GvHD and infection incidence and severity between UCBT and allogeneic stem cell transplantation, and may require a different approach for adoptive cellular immunotherapy. The mechanism(s) associated with these differences require further elucidation.

Feasibility study of IL-11 and granulocyte colony-stimulating factor after myelosuppressive chemotherapy to mobilize peripheral blood stem cells from heavily pretreated patients.

Purpose Pediatric patients with solid tumors treated with prolonged dose-intensive chemoradiotherapy are poor mobilizers of peripheral blood stem cells (PBSC). We have conducted a pilot study to mobilize PBSC in eight pediatric patients with relapsed solid tumors using ifosfamide, carboplatin, and etoposide (ICE) followed-up by IL-11 plus granulocyte colony-stimulating factor (G-CSF). Patients and Methods Patients received ifosfamide 1.8 g/m 2 per day for 5 days, carboplatin 400 mg/m 2 per day for 2 days, and etoposide 100 mg/m 2 per day for 5 days. After completion of ICE chemotherapy, patients received daily subcutaneous injections of G-CSF (5 &mgr;g/kg per day) and IL-11 (50–100 &mgr;g/kg per day) until peripheral stem cell apheresis. Results The median age was 11 years. Diagnosis included three relapsed Hodgkin disease, three relapsed central nervous system tumors, one relapsed Wilms tumor, and one relapsed rhabdomyosarcoma. The median number of apheresis procedures required to obtain 5 × 10 6 CD34 + cells/kg was one. The mean ± standard error of mean (SEM) total CD34 + cells collected was 14.0 ± 2.7 × 10 6 /kg. The mean ± SEM total CD34 + /CD41 + cells collected was 4.6 ± 1.9 × 10 6 /kg. Seven of the eight patients have subsequently undergone myeloablative chemotherapy with autologous PBSC transplantation and have reconstituted hematopoiesis with a median time to neutrophil recovery of 10 days and platelet recovery of 15.5 days. Conclusions We conclude that the regimen of ICE/IL-11 plus G-CSF is successful in mobilizing large numbers of CD34 + PBSC cells with a limited number (one) of apheresis collections in patients that have previously been heavily pretreated with chemotherapy/radiotherapy.

Autologous bone marrow transplantation for childhood acute lymphoblastic leukemia: a novel combined approach consisting of ex vivo marrow purging, modulation of multi-drug resistance, induction of autograft vs leukemia effect, and post-transplant immuno- and chemotherapy (PTIC).

In an attempt to reduce the high relapse rate associated with ABMT, five children with high-risk first CR and 19 in second or subsequent CR lacking matched family allogeneic donors underwent ABMT with chemopurged bone marrow utilizing verapamil (VPL), vincristine, and VP-16. Patients were conditioned with TBI, VPL bolus and infusion with VP-16 and cyclophosphamide. The first cohort of patients (n = 4) received only cyclosporin A (CsA). The second cohort (n = 7) received CsA and alpha interferon (total = 11 with post-transplant immunotherapy alone.) The third cohort (n = 13) received CsA and six alternating cycles of αIFN and chemotherapy and six additional cycles of chemotherapy (vincristine, VP-16, Ara-C, prednisone) followed by G-CSF (post-transplant immune chemotherapy (PTIC)). The 2-year DFS is 42 ± 10% (90% confidence interval (CI) is 26.5–58.5%) and 2-year overall survival is 54 ± 10% (90% CI is 37.5–70.5%). Furthermore, patients receiving PTIC (n = 13) vsimmunotherapy alone (CsA ± αIFN) (n = 11) had a substantially better 2 year DFS and OS: 69 ± 13% vs 13 ± 12% and 85 ± 10% vs 25 ± 15% (P = 0.008 and P = 0.06, respectively). These results suggest that the use of ABMT with chemopurging, combined with PTIC is well tolerated and may be an alternative new approach in the treatment of a subset of children with high-risk first CR or ⩾ second CR ALL who lack closely matched family-related allogeneic donors. Bone Marrow Transplantation (2001) 27, 145–153.

Ten Fold Ex-vivo Expansion of Allostimulatory Dendritic Cells (DC) from Cord Blood by Flt-3 Ligand, GM-CSF, TNF-|[alpha]|, IL-4 and Autologous Plasma: Implications for Strategies for Neonatal Vaccinations and/or Post Cord Blood Transplant Immunotherapy |[diams]| 1378

Dendritic Cells (DC) are potent antigen presenting cells and are considered important cellular components for immunoregulation. Cord blood (CB) has recently been recognized as an alternative source of stem cells however transplant recipients often experience delayed immune reconstitution. DC may be useful for enhancing immunity against infection and/or malignant disease. In this study, we explored the use of 10% autologous plasma to generate DC from CB adherent MNC. CB was collected from scheduled Cesaren-section or vaginal deliveries and CB MNC were collected by Ficoll-hypaque density centrifugation. Plasma was recovered from the supernatant and heat inactivated at 56°C. The plastic adherent population was cultured in AIM-V with 10% CB plasma supplemented with GM-CSF (100 ng/ml) TNF-α, (2.5 ng/ml), Flt3-Ligand (25 ng/ml) and IL-4 (5 ng/ml). Control without cytokines and/or 10% plasma were also cultured. Cytokine cultured cells developed characteristic DC morphology with many slender, elongated, and/or numerous fine membrane projections. By immunohistochemistry these morphologically distinct cells were CD1a+ and CD14-. Control cells maintained macrophage appearance of large adherent cells without membranous projections and were CD14+ but CD1a-. Cytokine cultured cells had significant phenotypic changes(confluent culture vs. day 0, mean ±SEM) consistent with DC expression of CD1a+CD80+ (7.5±1.4% vs. 0.9±0.2%, p<0.01, n=6) (8-fold) and CD1a+CD80+CD86+ (5.3±1.2% vs. 0.6±0.2%, p<0.01, n=6)(10-fold) with a fall of CD14+ (5.6±1.6% vs. 33.2±5.7, p<0.01, n=6). Allogenic primary Mixed Lymphocyte Reaction (MLR) with T-cells enriched by column was significantly increased over CB adherent cells by 351±49% (p=0.001, n=3) at ratio of 1:5 and 160±13% (p=0.002, n=3) at ratio of 1:25 (DC:T-cell). In summary, DC can effectively be generated with 10% autologous plasma from CB adherent MNC, acquire co-stimulatory molecules and are powerful stimulators of T-cell alloreactivity.