Auranofin in the treatment of juvenile rheumatoid arthritis

Auranofin mitigates systemic iron overload and induces ferroptosis via distinct mechanisms

Iron homeostasis is essential for health; moreover, hepcidin-deficiency results in iron overload in both hereditary hemochromatosis and iron-loading anemia. Here, we identified iron modulators by functionally screening hepcidin agonists using a library of 640 FDA-approved drugs in human hepatic Huh7 cells. We validated the results in C57BL/6J mice and a mouse model of hemochromatosis (Hfe^−/− mice). Our screen revealed that the anti-rheumatoid arthritis drug auranofin (AUR) potently upregulates hepcidin expression. Interestingly, we found that canonical signaling pathways that regulate iron, including the Bmp/Smad and IL-6/Jak2/Stat3 pathways, play indispensable roles in mediating AUR’s effects. In addition, AUR induces IL-6 via the NF-κB pathway. In C57BL/6J mice, acute treatment with 5 mg/kg AUR activated hepatic IL-6/hepcidin signaling and decreased serum iron and transferrin saturation. Whereas chronically treating male Hfe^−/− mice with 5 mg/kg AUR activated hepatic IL-6/hepcidin signaling, decreasing systemic iron overload, but less effective in females. Further analyses revealed that estrogen reduced the ability of AUR to induce IL-6/hepcidin signaling in Huh7 cells, providing a mechanistic explanation for ineffectiveness of AUR in female Hfe^−/− mice. Notably, high-dose AUR (25 mg/kg) induces ferroptosis and causes lipid peroxidation through inhibition of thioredoxin reductase (TXNRD) activity. We demonstrate the ferroptosis inhibitor ferrostatin significantly protects liver toxicity induced by high-dose AUR without comprising its beneficial effect on iron metabolism. In conclusion, our findings provide compelling evidence that TXNRD is a key regulator of ferroptosis, and AUR is a novel activator of hepcidin and ferroptosis via distinct mechanisms, suggesting a promising approach for treating hemochromatosis and hepcidin-deficiency related disorders.

Comparative tolerability of treatments for juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) includes several forms of chronic arthritis in children. Treatments are chosen according to the type and severity of the disease. Nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids remain the mainstays of therapy. Traditional slower acting anti-rheumatic drugs, such as gold therapy, penicillamine, sulfasalazine, tiopronin and hydroxychloroquine, are usually poorly active in children. In addition, adverse effects are common, including severe macrophage activation syndrome with gold therapy or sulfasalazine. Low dose, once weekly methotrexate has emerged as the therapeutic agent of choice for children who fail to respond adequately to the administration of an NSAID, especially in those with the extended oligoarticular subtype of the disease. Other immunosuppressive agents, such as cyclosporin, are sometimes combined with methotrexate. In recent years, novel treatments have been developed. Autologous hematopoietic stem cell transplantation is effective in a number of children with severe JIA, whose disease has been refractory to conventional therapy. However, only short term follow-up data are currently available for this novel therapy. In addition, severe infections complicated by macrophage activation syndrome and death have been reported. Finally, anti-tumour necrosis factor-alpha therapy has shown efficacy in more than two-thirds of children with JIA and polyarthritis, and other cytokine inhibitors may be soon available.

Network in pediatric rheumatology: the example of the Pediatric Rheumatology International Trials Organization

BACKGROUND

Pediatric rheumatic diseases (PRDs) are rare conditions associated with significant sequelae affecting the quality of life and long-term outcome. The research aimed at studying new therapeutic approaches is difficult because of logistic, methodological and ethical problems.

DATA SOURCES

To address these problems, two international networks, the Pediatric Rheumatology Collaborative Study Group (PRCSG) and the Pediatric Rheumatology International Trials Organization (PRINTO) were established. The two networks share the goal to promote, facilitate and conduct high quality research for PRDs.

RESULTS

The PRINTO and PRCSG networks have standardized the evaluation of response to therapy in juvenile idiopathic arthritis (JIA), juvenile systemic lupus erythematosus, and juvenile dermatomyositis, drafted clinical remission criteria in JIA, and provided cross-cultural adapted and validated quality of life instruments including the Childhood Health Assessment Questionnaire and the Child Health Questionnaire into 32 different languages. In this paper we reviewed how the networks of the PRINTO and PRCSG have created the basic premises for the best future assessment of PRDs.

CONCLUSIONS

The PRINTO and PRCSG networks can be regarded as a model for international cooperation or collaboration in other pediatric subspecialties.

International research networks in pediatric rheumatology: the PRINTO perspective

PURPOSE OF REVIEW

The purpose of this review is to highlight the problems and possible solutions for the conduct of international collaborative research for pediatric rheumatic diseases.

RECENT FINDINGS

Pediatric rheumatic diseases are rare conditions associated with important sequelae on the quality of life and long-term outcome. The research aimed at studying new therapeutic approaches is difficult because of logistic, methodological, and ethical problems. To face these problems, two international networks have been founded: the Pediatric Rheumatology Collaborative Study Group (or PRCSG) and the Paediatric Rheumatology international Trials Organization (or PRINTO). The two networks have the goal to promote, facilitate, and conduct high-quality research into pediatric rheumatic diseases. In particular they have been able to standardize the evaluation of response to therapy in juvenile idiopathic arthritis, juvenile systemic lupus erythematosus, and juvenile dermatomyositis; to draft clinical remission criteria in juvenile idiopathic arthritis; and to provide cross-cultural adapted and validated quality-of-life instruments like the Childhood Health Assessment Questionnaire and the Child Health Questionnaire in 32 different languages.

SUMMARY

The creation of large international trial networks such as PRINTO and PRCSG, the definition of internationally recognized and standardized outcome measures and definitions of improvement, the validation of quality-of-life instruments, and the adoption of adequate legislative measures (pediatric rule) have created the basic premises for the best future assessment of pediatric rheumatic diseases. This progress now affords children with pediatric rheumatic diseases the same opportunities as adults to be treated with drugs whose safety and efficacy have been assessed through legitimate scientifically valid investigations.

Juvenile rheumatoid arthritis: therapeutic perspectives

Juvenile rheumatoid arthritis (JRA) is the most common childhood chronic systemic autoimmune inflammatory disease. The therapeutic approach to JRA has, to date, been casual and based on extensions of clinical experiences gained in the management of adult rheumatoid arthritis (RA). The physiology of inflammation has been systemically studied and this has led to the identification of specific therapeutic targets and the development of novel approaches to the management of JRA. The classical treatments of the disease such as methotrexate, sodium aurothiomalate and sulfasalazine, are not always effective in controlling RA and JRA. This has necessitated the development of novel agents for treating RA, most of which are biological in nature and are targeted at specific sites of the inflammatory cascades. These biological therapeutic strategies in RA have proved successful and are being applied in the management of JRA. These developments have been facilitated by the advances in molecular biology which have heralded the advent of biodrugs (recombinant proteins) and gene therapy, in which specific genes can be introduced locally to enhance in vivo gene expression or suppress gene(s) of interest with a view to down-regulating inflammation. Some of these biodrugs, such as anti-tumor necrosis factor alpha (anti-TNFalpha), monoclonal antibodies (infliximab, adalimumab), TNF soluble receptor constructs (etanercept) and interleukin-1 receptor antagonist (IL-1Ra) have been tested and shown to be effective in RA. Etanercept has now been licensed for JRA. Clinical trials of infliximab in JRA are planned. Studies show that the clinical effects are transient, necessitating repeated treatments and the risk of vaccination effects. Anti-inflammatory cytokines such as IL-4, IL-10, transforming growth factor-beta and interferon-beta (IFN-beta) are undergoing clinical trials. Many of these agents have to be administered parenterally and production costs are very high; thus, there is a need, especially for pediatric use, to develop agents that can be taken orally. Long-term studies will be required to assess the tolerability and toxicity of these approaches in JRA, since cytokines and other mediators play important roles in host defenses, and the chronic inhibition, exogenous administration or constitutive over-expression of some cytokines/mediators may have undesirable effects.

Juvenile Rheumatoid Arthritis

Juvenile rheumatoid arthritis (JRA) is a common disorder of childhood that can be potentially devastating physically and psychologically. Over the last several decades, therapy for JRA has changed little. Therapy for advanced JRA is based on trial and error due to the lack of significant clinical trials for both old and new pharmaceutical agents. The following article is a brief overview of the disease and a review of the different treatment options available today with a look at some of the future developments in JRA research.

A risk-benefit assessment of slow-acting antirheumatic drugs in rheumatoid arthritis

There is no ideal slow-acting antirheumatic drug. Therapy of rheumatoid arthritis (RA) is currently being modified, with strong recommendations to abandon the traditional pyramidal approach. The call is for a more aggressive, earlier approach to suppress inflammation. Combination therapy rather than the use of a single agent is advocated by some. Improved methods for assessing disease activity as well as measurement of outcome have been developed. Markers of poor prognosis have helped to define patients for earlier treatment. Comparison of toxicity among such a diverse group of drugs is probably best achieved with a toxicity index measuring the number of episodes expressed in terms of patient-years of exposure. Toxicity remains the commonest reason for discontinuing an agent, while remission beyond 36 months on therapy is uncommon, except with methotrexate. The profile of toxicity is clearly defined for individual agents, but combination therapy may reveal an entirely different set of toxic manifestations. There is an urgent need to develop a set of risk factors to predict toxicity in an individual patient. Juvenile chronic arthritis behaves differently from adult RA. Drug toxicity profiles are similar, but less common. Outcome is more difficult to measure, with the major impact of disease and therapy being on growth retardation.

Comparative efficacy and safety of advanced drug therapy in children with juvenile rheumatoid arthritis

Results from three randomized placebo-controlled trials were combined in a meta-analysis to compare the clinical utility of four advanced drug therapy agents used to treat juvenile rheumatoid arthritis (JRA): D-penicillamine (10 mg/kg/d), hydroxychloroquine (6 mg/kg/d), auranofin (oral gold, 0.15 to 0.20 mg/kg/d), and two low dose levels of methotrexate [5MTX, 5 mg/M2/wk; 10MTX, 10 mg/M2/wk]. A total of 520 children with JRA were enrolled into these trials. Only 10MTX resulted in significantly greater improvement than placebo in variables that assess effectiveness: physician's global assessment, a composite index, and erythrocyte sedimentation rate. Treatment effect sizes were the largest in the 10MTX group for all articular disease indices. The short-term safety profiles were similar across all treatment groups. It is concluded that the current trend among pediatric rheumatologists to use oral methotrexate as the first advanced drug therapy in JRA is appropriate and that the minimum effective dose is 10 mg/M2/wk.

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.

Characteristics of responders and nonresponders to slow-acting antirheumatic drugs in juvenile rheumatoid arthritis

A 12-month double-blind, parallel, randomized, placebo-controlled multicenter trial of D-penicillamine and hydroxychloroquine was conducted in 162 children with juvenile rheumatoid arthritis in the United States and in the Union of Soviet Socialist Republics. No statistically significant intergroup differences were detected in primary outcome variables. We investigated the possible existence of select subgroups of patients who have a higher likelihood of response to active drugs than to placebo. Using previously published criteria, each patient was classified as a responder or nonresponder, and their demographic and disease characteristics at baseline were compared. We were unable to identify a subgroup of individuals who were more likely to respond to D-penicillamine or hydroxychloroquine than to placebo.

The total cost of care and the use of pharmaceuticals in the management of rheumatoid arthritis: the Medi-Cal program

Medicaid claims data were analyzed to investigate the prevalence and cost of rheumatoid arthritis (RA) in the Medi-Cal program. It was estimated that approximately 24,000 Medi-Cal recipients receive treatment for RA each year. The sample of Medi-Cal RAs studied averaged more than $2500 annually in total direct health care expenditures. The total cost of RA to Medi-Cal is projected to be $19.26 million (+/- $0.90 million) annually. Inclusion of possible gastrointestinal side effects of drug therapy increases the total cost to $20.49 million (+/- $0.91 million). While only 6.5% of the sample of RAs were hospitalized and 4.9% received nursing home care annually, these services are estimated to account for nearly 70% of RA-related expenditures. Less than 7% of Medi-Cal RAs receive disease modifying antirheumatic drugs (DMARDs). More than 75% of Medi-Cal RAs received aspirin or NSAIDs. These relieve pain and inflammation, but have not been demonstrated to halt the process of joint destruction.

Arthritis in children

Arthritis in children may result from many conditions. The rheumatic diseases, including juvenile rheumatoid arthritis, the spondyloarthropathies, rheumatic fever, lupus erythematosus, dermatomyositis, and the various vasculitis syndromes all can cause arthritis; these diseases are distinguished by their characteristic clinical appearances. Several nonrheumatic disorders such as infections, malignancies, congenital or genetic conditions, orthopedic conditions, and psychological disorders may closely simulate the various rheumatic diseases. The evaluation of children with arthritis rests chiefly on historical and physical findings; radiographs, laboratory tests, and occasionally biopsies also may be helpful. It is particularly important to identify specifically treatable diseases, such as bacterial infections or childhood malignancies, early and to avoid labeling nonrheumatic conditions as rheumatic. Accurate diagnosis of the various rheumatic disease syndromes is important for optimal therapy.

Penicillamine and hydroxychloroquine in the treatment of severe juvenile rheumatoid arthritis. Results of the U.S.A.-U.S.S.R. double-blind placebo-controlled trial

One hundred sixty-two children with severe juvenile rheumatoid arthritis were entered in a randomized, double-blind, placebo-controlled 12-month clinical trial designed to establish the efficacy and safety of two slower-acting antirheumatic drugs, penicillamine and hydroxychloroquine. The study was a cooperative effort of the United States and the Soviet Union. One group of subjects received 10 mg of penicillamine per kilogram of body weight per day, another group received 6 mg of hydroxychloroquine per kilogram daily, and a third group received placebo. All three groups were allowed a single concurrent nonsteroidal antiinflammatory drug, but no other antirheumatic medications, including corticosteroids. All three groups had dramatic improvement in many of the clinical and laboratory outcome variables after one year of study. There were no significant differences in efficacy between the penicillamine and placebo groups. Pain on movement was the only index of articular disease that was alleviated more by hydroxychloroquine than by placebo. Serious adverse drug reactions attributable to the active agents were rare. We were unable to demonstrate that, in the presence of a nonsteroidal antiinflammatory drug, either penicillamine or hydroxychloroquine is superior to placebo in the treatment of children with juvenile rheumatoid arthritis.

Evaluation of D-penicillamine in juvenile chronic arthritis. A double-blind, multicenter study

Seventy-four children with juvenile chronic arthritis were entered into a 6-month, multicenter, comparative double-blind study of the efficacy of D-penicillamine versus placebo. The results were evaluated in 70 patients, 55 of whom completed 6 months of the study. Improvement was observed in the total number of stiff joints, total number of painful joints, and total severity index measuring joint pain. There was also a significant reduction in the concurrent use of nonsteroidal anti-inflammatory drugs. D-penicillamine was well-tolerated in all but 2 patients. Some children in the placebo group exhibited definite improvement; however, relapses that were observed were mainly in that group. These results confirm the efficacy of D-penicillamine for the treatment of joint involvement in juvenile chronic arthritis.

Gold sodium thiomalate and D-penicillamine. A controlled, comparative study in patients with pauciarticular and polyarticular juvenile rheumatoid arthritis

Seventy-seven consecutive patients with pauciarticular or polyarticular juvenile rheumatoid arthritis were randomized to treatment with either gold sodium thiomalate (GSTM) or D-penicillamine (PEN) in a parallel 50-week clinical trial. Adverse reactions were reported by or observed in 9 GSTM-treated and 15 PEN-treated patients. Of these, 5 and 7 respectively were withdrawn from the study. Most disease activity measurements were changed in favour of the GSTM group, compared with the PEN group, but significant differences between the treatment regimens were observed for only a few measurements. This possible advantage of GSTM with regard to efficacy was only seen in patients with the polyarticular disease type.

Auranofin in juvenile rheumatoid arthritis. An open label, non-controlled study

An open label, non-controlled trial of six-month duration was designed to determine the safety and efficacy of auranofin in the treatment of 13 children with polyarticular JRA. Adverse reactions were observed in 5 of the 13 patients (38%) but only in one was it serious enough to discontinue treatment. None of the patients developed diarrhea or hematologic abnormalities. Therapeutic response was evaluated in the 11 patients who completed the six-month treatment. According to the final overall assessment 9 of the 11 children had improved, one remained unchanged and one worsened. After four months of treatment serum gold levels in 11 patients ranged between 28 and 59 micrograms/dl, with a mean value of 34 micrograms/dl. There was no correlation between serum gold levels and the frequency and severity of side effects.

Auranofin. A preliminary review of its pharmacological properties and therapeutic use in rheumatoid arthritis

Auranofin is the first orally active gold compound for the treatment of rheumatoid arthritis. Like other chrysotherapeutic agents, its exact mechanism of action is unknown, but it probably acts via immunological mechanisms and alteration of lysosomal enzyme activity. Although long term clinical experience with auranofin is limited, its efficacy appears to approach that of sodium aurothiomalate. Further comparative studies with aurothioglucose, hydroxychloroquine and D-penicillamine are required before definitive statements can be made regarding the relative efficacy of auranofin and these agents. While patients have demonstrated clinical remission of rheumatoid arthritis in response to auranofin therapy, radiological studies have been inconclusive regarding its effect on the occurrence or progression of erosive lesions. Auranofin is relatively well tolerated in most patients, but diarrhoea, skin rash, and pruritus are sometimes troublesome, and thrombocytopenia and proteinuria are potentially serious side effects which may occur during therapy. Whereas mucocutaneous side effects are more frequent with injectable gold compounds, gastrointestinal reactions are the most common adverse effect seen with auranofin. The frequency of side effects has been similar with auranofin and sodium aurothiomalate, but they are generally less severe with auranofin. While some of the side effects are controlled by a reduction in dosage, temporary or permanent withdrawal of auranofin may be necessary. Auranofin is clearly a useful addition to the limited list of agents with disease-modifying potential presently available for the treatment of rheumatoid arthritis. It will doubtless generate much interest as its final place in therapy becomes better defined through additional well-designed studies and wider clinical experience.

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

During an uncontrolled, open-labelled, open-ended clinical trial of auranofin in children with juvenile rheumatoid arthritis (JRA) we obtained serial blood samples for the purpose of assessing gold content. Our objectives were (1) to observe the pattern of blood gold concentrations over a period of time in children undergoing long-term oral gold therapy, and (2) to observe the effect of changing dosage levels on blood gold concentrations. The initial dosage of auranofin was 0.1 mg/kg/day with allowable increases to 0.2 mg/kg/day. A concurrent nonsteroidal anti-inflammatory drug was allowed. Twenty-one patients were enrolled in the study, and we obtained 2 or more serial samples on 13 of the children. At a constant dosage of 0.1 mg/kg/day, steady state blood gold concentrations were attained in 11 to 13 weeks of therapy and, in the absence of a dosage change, remained remarkably constant through extended periods. The blood gold concentration was related to total daily dosage rather than to the cumulative amount of gold received. Increasing or decreasing the dose resulted in a direct effect on concentration. The clinical value of blood gold levels resulting from auranofin therapy in JRA will have to be established through double-blind controlled trials.

Early experiences with auranofin in juvenile rheumatoid arthritis

Pharmacologic management of juvenile rheumatoid arthritis is only one of several modalities necessary for effective control. The stepping stones to proper management include a planned long-range program, physical therapy with swimming, good health habits, and consultation with other health professionals who are part of the management team. Pharmacologic therapy includes nonsteroidal anti-inflammatory drugs initially, occasionally corticosteroids, and slow-acting antirheumatic drugs, including injectable gold when therapeutic response is inadequate. Early experiences with oral gold are reported here. Auranofin (triethylphosphine gold) was administered to 21 patients with juvenile rheumatoid arthritis during a segment I, open ended, open-label, noncontrolled trial designed to establish safety and preliminary efficacy. Initial dosage was 0.1 mg/kg per day; incremental increases to 0.2 mg/kg per day were allowed (with usual increase to 0.15 mg/kg per day). Aspirin (80 mg/kg per day) or tolmetin (20 to 40 mg/kg per day), or naproxen (400 to 600 mg/m2 per day) were allowed as rapidly acting antiinflammatory agents. Stable measurable plasma concentrations of gold were attained in all patients during the study. More than half the patients sustained clinically significant improvement (greater than 25 percent) with regard to the number and severity of joints with swelling, pain on motion, and tenderness. In nine of the 19 patients, the total number of joints with active arthritis decreased by at least 25 percent. All articular disease indices measured indicated improvement of group mean changes between the initial and final visit. Eleven of 16 patients with an elevated erythrocyte sedimentation rate showed decreases of at least 25 percent. The group given higher dosages had a greater proportion of responders in regard to decreases in erythrocyte sedimentation rate (nine of 11 patients). Four of six patients whose serums contained rheumatoid factor showed decreases in the titers. Discontinuation of auranofin was necessary in two patients: one because of headache and one because of hematuria and anemia associated with a severe flare-up of polyarticular disease. The results from this trial reveal sufficient patient improvement to plan a double-blind trial of auranofin in children with juvenile rheumatoid arthritis.