A Fenton-like cation can improve arsenic trioxide treatment of sclerodermatous chronic Graft-versus-Host Disease in mice.

Graft-versus Host Disease (GvHD) is a major complication of hematopoietic stem cell transplant. GvHD is characterized by the chronic activation of immune cells leading to the development of systemic inflammation, autoimmunity, fibrosis and eventually death. Arsenic trioxide (ATO) is a therapeutic agent under clinical trial for the treatment of patients with systemic lupus erythematosus (SLE) and chronic GvHD (cGvHD). This therapy is admittedly rather safe although adverse effects can occur and may necessitate short interruptions of the treatment. The aim of this study was to combine ATO with a divalent cation, to generate a Fenton or Fenton-like reaction in order to potentiate the deletion of activated immune cells through the reactive oxygen species (ROS)-mediated effects of ATO in a mouse model, and thereby enabling the use of lower and safer ATO concentrations to treat patients with cGvHD. In vitro, among the various combinations of divalent cations tested, we observed that the combination of ATO and CuCl2 (copper chloride) induced a high level of oxidative stress in HL-60 and A20 cells. In addition, this co-treatment also decreased the proliferation of CD4+ T lymphocytes during a mixed lymphocyte reaction (MLR). In vivo, in a cGvHD mouse model, daily injections of ATO 2.5 µg/g + CuCl2 0.5 µg/g induce a decrease in lymphocyte activation and fibrosis that was equivalent to that induced by ATO 5 µg/g. Our results show that the addition of CuCl2 improved the effects of ATO and significantly limited the development of the disease. This co-treatment could be a real benefit in human patients to substantially decrease the known ATO side effects and optimize ATO treatment in pathologies characterized by activated cells sensitive to an increase in oxidative stress.

High Response Rate and Corticosteroid Sparing with Arsenic Trioxide-Based First-Line Therapy in Chronic Graft-versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation.

Chronic graft-versus-host disease (cGVHD) occurs in 20% to 50% of recipients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Corticosteroids (CS) remain the first-line therapy but have suboptimal efficacy and carry a risk of long-term side effects. New agents with a better safety profile and higher efficacy are urgently needed. This study aimed to evaluate the efficacy and safety of a first-line combination of arsenic trioxide (ATO) and CS in adult patients with cGVHD requiring systemic therapy after first allo-HSCT for a hematologic disease. In this prospective national multicenter single-arm open-label Phase II study conducted in 5 university hospital centers in France, ATO was started within 10 days of CS at 1 mg/kg/day. Patients received 11 infusions per cycle of 28 days at a dose of .15 mg/kg per infusion. According to the clinical response and depending on the clinician's opinion, patients received 1 or 2 cycles of treatment. Cycles were separated by an 8- to 11-week interval from the first infusion of ATO. Patients were evaluated at 6 weeks, 14 weeks, 6 months, 9 months, and 12 months after the first ATO infusion, using the Chronic GVHD Activity Assessment Form A. The primary endpoint was preliminary efficacy based on the overall response rate (ORR; complete response [CR] or partial response [PR]) at 6 months. Response rates were estimated with 2-sided 95% exact confidence intervals (CIs). Twenty-one patients entered the study and received at least 1 ATO infusion (1 incomplete cycle for 1 patient, 1 complete cycle for 11 patients, and 2 complete cycles for 9). Six patients continued ongoing cyclosporine A (CsA) treatment after inclusion, and 4 other patients resumed CsA treatment during the study. The ORR at 6 months was 75.0% (95% CI, 50.9% to 91.3%), with CR in 35% and PR in 40%. Failure-free survival was 90.0% (95% CI, 65.6% to 97.4%) at 6 months and 65.0% (95% CI, 40.3% to 81.5%) at 12 months. The progression-free survival rate was 95.0% (95% CI, 69.5% to 99.3%) at 6 months and 83.8% (95% CI, 57.7% to 94.5%) at 12 months. The mean CS dose was decreased by 74.6 ± 32.7% from baseline to the 6-month visit and by 91.0 ± 14.6% from baseline to the 12-month visit. CS was definitively stopped in 30.0% of patients at the 6-month visit and in 47.4% at the 12-month visit. Two patients died, at 7 months and 12 months after the first ATO infusion from causes unrelated to ATO. One patient withdrew because of transient hepatotoxicity. The first-line combination of ATO and CS was associated with a high clinical response rate and rapid CS sparing in cGVHD after previous allo-HSCT.

Safety and efficacy of low-dose intravenous arsenic trioxide in systemic lupus erythematosus: an open-label phase IIa trial (Lupsenic).

BACKGROUND: Lupus animal model has shown that arsenic trioxide (ATO), a treatment of acute promyelocytic leukaemia, could be effective in SLE. This is the first clinical study to determine the safety and efficacy of a short course of intravenous ATO in patients with active SLE. METHODS: This phase IIa, open-label, dose-escalating study enrolled 11 adult SLE patients with a non-organ threatening disease, clinically active despite conventional therapy. Patients received 10 IV infusions of ATO within 24 days. The first group received 0.10 mg/kg per injection, with dose-escalating to 0.15 mg/kg in a second group, and to 0.20 mg/kg in a third group. The primary endpoint was the occurrence of adverse events (AEs) and secondary endpoints were the number of SLE Responder Index 4 (SRI-4) responders at week 24 and reduction of corticosteroid dosage. In an exploratory analysis, we collected long-term data for safety and attainment of lupus low disease activity state (LLDAS). RESULTS: Four serious AEs occurred (grade 3 neutropenia, osteitis, neuropathy), 2 of which were attributable to ATO (neutropenia in the 2 patients treated with mycophenolate). Two patients suffered a severe flare during the last 4 weeks of the trial. At W24, five patients among 10 were SRI-4 responders. Overall, mean corticosteroid dosage decreased from 11.25 mg/day at baseline to 6 mg/day at W24 (P < 0.01). In the long term, 6 patients attained LLDAS at W52, which continued at last follow-up (median LLDAS duration 3 years, range 2-4). CONCLUSIONS: A short course of ATO has an acceptable safety profile in SLE patients and encouraging efficacy. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01738360  registered 30 November 2012.

The HERV-W/7q family in the human genome. Potential for protein expression and gene regulation.

A new family of human endogenous retroviruses has recently been discovered. The best known example of a full length member of this family, HERV-W/7q, is located on chromosome 7. HERV-W/7q is characterized by a long open reading frame within its env gene which is expressed in various tissues, and mainly in placenta, as a protein that we called enverin. A search for new retroviral sequences related to the HERV-W/7q family allowed the characterization of such elements in chromosome 6. A novel full length HERV with an env gene of the HERV-W/7q type, potentially encoding a truncated form of enverin has been identified on chromosome 10. The distribution of HERV-W/7q related sequences close to or within genes offers the possibility that the expression of these genes may be regulated by their companion retroviral sequences.