Blood gold concentrations in children with juvenile rheumatoid arthritis undergoing long-term oral gold therapy

In silico and in vitro drug screening identifies new therapeutic approaches for Ewing sarcoma

The long-term overall survival of Ewing sarcoma (EWS) patients remains poor; less than 30% of patients with metastatic or recurrent disease survive despite aggressive combinations of chemotherapy, radiation and surgery. To identify new therapeutic options, we employed a multi-pronged approach using in silico predictions of drug activity via an integrated bioinformatics approach in parallel with an in vitro screen of FDA-approved drugs. Twenty-seven drugs and forty-six drugs were identified, respectively, to have anti-proliferative effects for EWS, including several classes of drugs in both screening approaches. Among these drugs, 30 were extensively validated as mono-therapeutic agents and 9 in 14 various combinations in vitro. Two drugs, auranofin, a thioredoxin reductase inhibitor, and ganetespib, an HSP90 inhibitor, were predicted to have anti-cancer activities in silico and were confirmed active across a panel of genetically diverse EWS cells. When given in combination, the survival rate in vivo was superior compared to auranofin or ganetespib alone. Importantly, extensive formulations, dose tolerance, and pharmacokinetics studies demonstrated that auranofin requires alternative delivery routes to achieve therapeutically effective levels of the gold compound. These combined screening approaches provide a rapid means to identify new treatment options for patients with a rare and often-fatal disease.

Embryonic oxidative stress results in reproductive impairment for adult zebrafish

Exposure to environmental stressors during embryo development can have long-term effects on the adult organism. This study used the thioredoxin reductase inhibitor auranofin to investigate the consequences of oxidative stress during zebrafish development. Auranofin at low doses triggered upregulation of the antioxidant genes gstp1 and prdx1. As the dose was increased, acute developmental abnormalities, including cerebral hemorrhaging and jaw malformation, were observed. To determine whether transient disruption of redox homeostasis during development could have long-term consequences, zebrafish embryos were exposed to a low dose of auranofin from 6–24 hours post fertilization, and then raised to adulthood. The adult fish were outwardly normal in their appearance with no gross physical differences compared to the control group. However, these adult fish had reduced odds of breeding and a lower incidence of egg fertilization. This study shows that a suboptimal early life environment can reduce the chances of reproductive success in adulthood.

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We exposed zebrafish embryos to the oxidative stress-inducing compound auranofin.

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Embryos showed a dose-dependent increase in developmental abnormalities.

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Exposed embryos responded by upregulating oxidative stress-responsive genes.

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Embryos transiently exposed to a low dose of auranofin were raised into adults.

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The resulting adults had reduced fertility compared with controls.

Drug treatment in children with juvenile rheumatoid arthritis. Past, present, and future

Rheumatology made its debut as a legitimate subspecialty of pediatrics sometime in the 1940s in Europe, and in the 1970s in North America. Therapy of juvenile rheumatoid arthritis has evolved from salicylates and gold injections to newer, less toxic nonsteroidal anti-inflammatory drugs and methotrexate. Corticosteroids remain as important drugs when life-threatening complications or blinding iridocyclitis develop. Immune response modifiers and gene therapies offer considerable potential for eventually halting or curing the disease but have yet to make a substantial impact on therapy. Methods for the correct conduct and interpretation of data from clinical trials are discussed.

Clinical pharmacokinetics of drugs used in juvenile arthritis

Juvenile arthritis is defined as the occurrence of objective evidence of arthritis for a minimum of 6 weeks, in a child 16 years of age or younger. With a reported incidence of 9 to 19.6 per 100,000 children, juvenile arthritis is considered to be a rare disease. There is no known cure; however, up to 75% of patients will undergo remission by late adolescence. Drugs used in the treatment of juvenile arthritis are divided into 2 major classes: (a) the nonsteroidal anti-inflammatory drugs (NSAIDs) including salicylates, naproxen, ibuprofen, fenoprofen, ketoprofen, flurbiprofen, indomethacin, sulindac, tolmetin and diclofenac, and (b) disease modifying agents which encompass drugs such as antimalarial agents, gold, methotrexate, penicillamine and sulfasalazine. In almost all the reports dealing with the pharmacokinetics of NSAIDs, the level of disease activity has not been noted. The level of activity is important since, during a flare, the plasma albumin may fall to the point that it causes a substantial and clinically significant increase in the unbound serum concentration of highly bound drugs. The relationship between the concentration of these drugs in the systemic circulation and their efficacy is not clear. However, for many of them, therapeutic drug monitoring is recommended as a means of reducing the possibility of toxic reactions. Further pharmacokinetic and -dynamic evaluations are needed for many of these drugs in juvenile arthritis.

Auranofin in the treatment of juvenile rheumatoid arthritis. Results of the USA-USSR double-blind, placebo-controlled trial. The USA Pediatric Rheumatology Collaborative Study Group. The USSR Cooperative Children's Study Group

A 6-month double-blind, parallel, randomized, placebo-controlled multicenter trial of auranofin (0.15-0.20 mg/kg/day) was conducted in 231 children with juvenile rheumatoid arthritis (JRA) in the United States and in the Union of Soviet Socialist Republics. Approximately 80% of the children had polyarticular disease. The auranofin-treated patients showed greater mean decreases from baseline in 11 of the 12 articular disease indices measured than did the placebo-treated subjects after 3 months of therapy, and in 9 of the 12 indices after 6 months. However, the actual intergroup mean differences were relatively small and were not statistically significant. According to the physician's global assessment, 69% of the auranofin-treated patients and 61% of the placebo-treated patients demonstrated clinically significant improvement from baseline after 6 months (P = 0.24). Children whose disease onset occurred less than 2 years prior to entry improved more than did those who had arthritis for a longer period. In addition, those with polyarticular involvement at baseline improved more than did patients with mild disease. However, these relationships were observed in both the auranofin- and placebo-treated groups, and again, there were no significant intergroup differences. Diarrhea was the most common adverse effect of auranofin. We conclude that the clinical efficacy of auranofin is modestly higher than that of placebo in the treatment of JRA, as evidenced by the consistent trends observed in the data. However, the magnitude of the individual intergroup differences is not statistically significant. Auranofin appears to be very safe in children with JRA.

Modulation of mediator release from human basophils and pulmonary mast cells and macrophages by auranofin

Auranofin, a new orally absorbable gold compound, inhibits IgE-(anti-IgE) and non-IgE-mediated (f-met-peptide and the Ca2+ ionophore A23187) histamine release from human basophils. Auranofin inhibits the release of histamine induced by phorbol myristate (TPA) and bryostatin 1 both in the presence and absence of extracellular Ca2+. Increasing the Ca2+ concentrations in the extracellular medium does not reduce the inhibitory effect of auranofin on anti-IgE- or A23187-induced secretion. Auranofin inhibits the de novo synthesis of sulfidopeptide leukotriene C4 (LTC4) induced by anti-IgE from basophils and mast cells purified from human lung. However, in both systems auranofin has a significantly greater inhibitory effect on LTC4 release than on histamine secretion. Finally, auranofin induces a concentration-dependent inhibition of A23187-induced leukotrine B4 (LTB4) release from purified human lung macrophages. These data suggest that auranofin modulates the release of preformed (histamine) and de novo synthesized (LTC4 and LTB4) chemical mediators from human inflammatory cells isolated from peripheral blood and human lung tissues.