No abstract

The available treatment options for hyponatremia secondary to SIADH are limited and not completely effective. Conivaptan is a vasopressin 1a and 2 receptor antagonist recently approved by the US Food and Drug Administration (FDA) for treating euvolemic and hypervolemic hyponatremia in adult patients. However, data on efficacy and safety of conivaptan in pediatrics are limited. We report a case of a 13-year-old boy with extensively metastasized anaplastic large-cell lymphoma. He also developed hyponatremia due to syndrome of inappropriate antidiuretic hormone secretion (SIADH) prior to chemotherapy initiation. SIADH management in this case was complicated when fluid restriction was not safely attainable. Conivaptan played a significant role in this situation by allowing provision of a large amount of intravenous fluid prior to and during induction chemotherapy. It proved to be an important component in preventing uric acid nephropathy/tumor lysis syndrome. Conivaptan induced free-water clearance as indicated by increased urine output and decreased urine osmolality. The patient responded to conivaptan without any adverse effects.

No abstract

We have found that ferritin heavy chain (FtH), an antioxidant/stress response/iron-storage protein, localizes to the nucleus in K562 cells and represses the human adult beta-globin promoter in transient assays in primate cells (Broyles et al., PNAS98: 9145, 2001). Since other work indicates FtH is also a gene activator of fetal-globin genes, we hypothesize that FtH is a long-sought developmental hemoglobin (Hb) switching factor and that delivery of FtH to human adult erythroid cell precursors will reverse the phenotype to HbF, offering a phenotypic cure for sickle cell disease (SCD). Chromatin immunoprecipitation (ChIP) assays, antisense treatments, and an FtH transgenic mouse have confirmed that FtH is a globin gene regulatory protein in vivo. With erythroid precursor cells from pediatric SCD patients, under an IRB-approved protocol, we have used a two-phase culture system for in vitro maturation of erythroid cells in the presence of FtH, delivered to the cells as pure protein, as an expression plasmid, or as a priority inducer compound that activates the endogenous FtH gene. HPLC with a PolyCAT A column was used to separate and quantify human Hbs. With each mode of delivery, FtH stimulated a complete switch from HbS to HbF. This result was repeatable in multiple experiments using erythroid precursor cells from three different SCD donors. Fluorescently-labeled recombinant human FtH protein was taken into red cell precursors in culture, suggesting that the purified protein can be directly delivered without gene therapy. This method of producing a phenotypic cure in SCD patients should be easy and inexpensive to deliver in vivo.

5155 Introduction: Deferasirox (Exjade®, Novartis Pharmaceuticals) is an oral iron chelator indicated for the treatment of transfusional iron overload. The recommended mode of administration is to be taken on an empty stomach in water, apple juice or orange juice ≥30 minutes before food. However, there have been post-marketing reports of discontinuation or reduced compliance of deferasirox secondary to palatability and gastrointestinal adverse events. Registration trials with deferasirox did not evaluate different food combinations in an attempt to maintain predictable plasma levels. Early single dose studies suggested that the bioavailability of deferasirox is increased when administered with or before meals, and is positively influenced by fat content, but is not affected by degree of dispersion nor type of liquid. Long-term pharmacokinetic and tolerability studies involving a food effect have not been conducted to date, and the ability of alternate methods of administration to improve patient compliance with iron chelation therapy is unknown. Method: This is an ongoing single-arm, open-label, multi-center study designed to evaluate the palatability, safety, tolerability and pharmacokinetics of deferasirox when administered with food, dispersed in any liquid of choice, or crushed and added to food. The patient population includes patients with transfusional hemosiderosis (minimum entry serum ferritin ≥500 μ g/L) aged >2 years with thalassemia major, sickle cell disease (SCD), low or intermediate (INT-1) risk MDS or other anemias, who are on, starting, or resuming treatment with deferasirox. The study began with a 1-month run-in phase with deferasirox dosed according to prescribing information, then a 3-month assessment phase where subjects could choose each week from 5 general administration options including with or without meals, in the morning or evening, crushed and added to a soft food, or mixed in a liquid of choice. Subject diaries are used to record the meal and method of administration at the end of each week. Palatability is assessed with a modified facial hedonic scale, with additional directed questions capturing gastrointestinal side effects. This is a data analysis of the run-in phase. Result: Target enrollment has been met with 65 patients. Baseline data on the first 58 subjects include 8 in the 2 to <10 years of age group (median 7.5 years; range 3–9); 42 in the 10 to <60 years of age group (median 18.5 years; range 10–48); and 8 in the ≥60 years of age group (median 74 years; range71-83). Underlying hematologic diagnoses included SCD (41%), thalassemia major (29%), MDS (12%) and other anemias (17%). Sixty-nine percent of subjects were receiving deferasirox prior to entering the study. The median baseline serum ferritin level was 2405 μ g/L (range 560–8660) and was distributed as shown in Table 1. The most frequent adverse events were diarrhea (19%) and nausea (9%) (Table 2), which were more common in MDS (P=0.23 and P<0.01, respectively). Conclusion: This ongoing trial (NCT00845871) is evaluating whether alternative modes of administration improve palatability and tolerability while maintaining safety. Preliminary data from the assessment phase (deferasirox taken with meals, different liquids, or crushed and added to food) will be presented at the meeting. Disclosures: Goldberg: Novartis Oncology: Consultancy, Honoraria, Research Funding, Speakers Bureau. Off Label Use: Exjade, iron chelation therapy, off-label method of administration. Giardina:Novartis: Research Funding. Parkhurst Cain:Novartis: Research Funding. Chirnomas:Novartis: Research Funding. Esposito:Novartis: Employment. Paley:Novartis: Employment. Vichinsky:Novartis: Consultancy, Research Funding, Speakers Bureau; Hemaquest: Consultancy, Membership on an entity's Board of Directors or advisory committees; Apotex: Consultancy, Research Funding.