Clinical trial of penicillamine in rheumatoid arthritis

Recent developments in the use of organic-inorganic nanohybrids for drug delivery

Organic-inorganic nanohybrid (OINH) structures providing a versatile platform for drug delivery with improved characteristics are an area which has gained recent attention. Much effort has been taken to develop these structures to provide a viable treatment options for much alarming diseases such as cancer, bone destruction, neurological disorders, and so on. This review focuses on current work carried out in producing different types of hybrid drug carriers identifying their properties, fabrication techniques, and areas where they have been applied. A brief introduction on understating the requirement for blending organic-inorganic components into a nanohybrid drug carrier is followed with an elaboration given about the different types of OINHs developed currently highlighting their properties and applications. Then, different fabrication techniques are discussed given attention to surface functionalization, one-pot synthesis, wrapping, and electrospinning methods. Finally, it is concluded by briefing the challenges that are remaining to be addressed to obtain multipurpose nanohybrid drug carriers with wider applicability. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Randomised placebo-controlled study of stopping second-line drugs in rheumatoid arthritis

BACKGROUND

A favourable benefit/risk ratio for treatment of rheumatoid arthritis (RA) with second-line drugs has been established only in short-term studies. The present investigation addresses the question of whether RA patients with a good response to long-term treatment with second-line drugs benefit from continuation of such treatment.

METHODS

A 52-week randomised double-blind placebo-controlled multicentre study was conducted to assess the effect of stopping second-line therapy in 285 RA patients with a good long-term therapeutic response. The patients either continued the second-line drug (n = 142) or received a placebo (n = 143). The endpoint was a flare, defined as recurrence of synovitis.

FINDINGS

At entry into the study median duration of second-line drug therapy was 5 years (range 2-33). At 52 weeks the cumulative incidence of a flare was 38% for the placebo group and 22% for the continued therapy group (p = 0.002). The risk of a flare was 2.0 times higher for patients receiving placebo than for those continuing the second-line drug (95% CI 1.27 to 3.17). The same trend was found for each second-line drug separately, with the exception of d-penicillamine. Side-effects that necessitated dose reduction or discontinuation occurred in 2 patients in each group.

INTERPRETATION

Second-line drugs continue to be effective in RA patients who have responded well to initial treatment.

D-penicillamine

D-Pen represents an effective treatment for a proportion of patients with RA and PSS. Its status in the treatment of juvenile RA is uncertain. The best results will be obtained by a skillful, careful physician maintaining careful surveillance for toxicity. Neither the mode of action nor the mechanisms of toxicity are well understood in RA. Consequently, safer and more effective analogues of D-pen have not been produced.

Sulphasalazine in rheumatoid arthritis: combination therapy with D-penicillamine or sodium aurothiomalate

This open study examined the safety of adding a second slow-acting anti-rheumatic drug (SARD) - D-penicillamine or sodium aurothiomalate - to the therapy of 38 rheumatoid patients already established on sulphasalazine. Combined anti-rheumatic therapy given in this way was generally well-tolerated and the incidence of adverse reactions was not increased. During the first year none of the reactions were serious although 9 of the 29 patients (31%) given D-penicillamine and 3 of the 9 patients receiving aurothiomalate developed side-effects requiring withdrawal of the second SARD. Reactions attributed to D-penicillamine were: gastro-intestinal - 6, rashes - 2, and blurring of vision - 1. All 3 reactions occurring with gold were rashes, 2 associated with proteinuria and one with increased liver enzymes. During the second year D-penicillamine was withdrawn in 4 patients due to thrombocytopenia - 2, and rashes - 2. In addition an overall favourable clinical response was achieved in 70% of patients. This approach for combination therapy whereby a second SARD is given to patients already established on a single SARD, appears to minimise the toxicity which is a problem when 2 SARDs are started simultaneously.

Progressive joint damage during penicillamine therapy for rheumatoid arthritis

Progressive joint damage characterises rheumatoid arthritis despite treatment with slow-acting drugs such as penicillamine. We examined a cohort of 145 RA patients, treated with 250 or 500 mg penicillamine daily for 18 months to study progressive joint damage measured using Larsen's standard radiographs. Overall damage increased significantly over 18 months at both doses of penicillamine. Radiological changes between 6-18 months were studied in detail in 55 cases. They were divided into rapidly progressive (increases in Larsen score of more than 5) or slowly progressive (increases in Larsen score of 5 or less). Overall clinical response, visual analogue pain score, ESR, haemoglobin and platelet count were significantly lower in the slowly progressive patients; articular index and duration of morning stiffness were slightly lower; latex titre, RAHA titre, joint size and white cell count showed no differences between groups. There is an indirect relationship between progressive joint damage and some clinical and laboratory measures. The reasons underlying our failure to control progression in some cases need further definition.

Rheumatoid arthritis: can the long-term outcome be altered?

Although several agents (for example, intramuscularly administered gold, auranofin, D-penicillamine, hydroxychloroquine, and methotrexate) are of clinical benefit in the management of rheumatoid arthritis (RA), their effect on the long-term outcome of the disease is controversial. Assessment of the influence of therapeutic interventions in RA is difficult because the natural history of the disease remains poorly defined and unpredictable, and neither the traditional clinical and laboratory measurements of inflammation nor radiographic analyses of progression of joint destruction provide an accurate estimate of the long-term outcome of RA. Furthermore, there is little evidence that second-line agents yield benefits beyond 3 years. Therefore, adequately tested comprehensive measures should be used in large, long-term, multicenter controlled clinical trials to determine whether the long-term outcome of RA can be altered.

Long-term outcome of treating rheumatoid arthritis: results after 20 years

Outcome of therapy, in terms of functional capacity, radiological measures of joint damage, erythrocyte sedimentation rate (ESR), rheumatoid factor, and mortality, was determined prospectively in 112 consecutive rheumatoid arthritis (RA) patients treated for 20 years at one centre, where a policy of active treatment was pursued with the use of gold, chloroquine, steroids, and, in resistant cases, penicillamine or cytotoxic drugs. By 20 years 35% were dead. Mortality was often attributable to RA. Function improved in the early years of treatment but declined considerably between 10 and 20 years. At 20 years 19% were severely disabled. Radiographs showed related evidence of increasing joint destruction. The ESR and rheumatoid factor levels changed little. Age, late presentation, and rheumatoid factor seropositivity at presentation were poor prognostic factors. The concept of "remission-inducing" drugs is fallacious. Early treatment may be advantageous, but the prognosis of RA is not good.

D-penicillamine: chemistry and clinical use in rheumatic disease

The discovery of D-penicillamine and its uses in medicine are reviewed. Chemical-physical properties are discussed, and the molecular structure of D-penicillamine and several of its reaction products are illustrated. Examples of its three main types of biochemical reactions--sulfhydryl-disulfide exchange, thiazolidine formation, and metal chelation are included. Trials of D-penicillamine in RA patients are reviewed critically. The administration of the drug is discussed in detail, including dosages, clinical and laboratory responses, patterns of adverse side effects or toxicity, drug-induced autoimmune diseases, indications and contraindications, and the monitoring and management of patients.

SA 96 (N-(2-mercapto-2-methylpropanoyl)-L-cysteine) in rheumatoid arthritis

SA 96 (N-(2-mercapto-2-methylpropanoyl)-L-cysteine) is a new sulfhydryl compound having a relatively similar chemical structure to Tiopronin and D-penicillamine. An open trial of SA 96 treatment (300 mg/day after meals for 16 weeks) was carried out in 11 patients with definite or classical rheumatoid arthritis and with therapeutic failure of previous gold salts and/or D-penicillamine therapy. Two cases were withdrawn from the trial, because of a side effect (hepatitis) in one patient and an unrelated illness in another. The results in the 9 patients completing the trial demonstrated statistically significant improvement in the clinical and laboratory measurements. A marked abatement of disease activity was noted in 5 of 9 patients who did not benefit from, or suffered a relapse during previous chrysotherapy and in 1 of 5 patients without benefit, or with relapse following previous D-penicillamine treatment. Among 4 patients who had discontinued D-penicillamine because of its intolerable cutaneous side effects, 3 patients completed the trial, with favourable results. The results of this trial seem to indicate that SA 96 is possibly of value as a slow-acting antirheumatic drug in some patients with therapeutic failure of gold salts or D-penicillamine.

Joint damage in rheumatoid arthritis: radiological assessments and the effects of anti-rheumatic drugs

Joint damage is a major problem in the long-term course of rheumatoid arthritis. It is usually assessed radiologically. In this review the methods of measuring the radiological changes are outlined, and the effects of anti-rheumatic drugs on radiological progression summarised. Two methods of scoring radiographs have become standard techniques; these are the Sharp index and the Larsen index. They both concentrate on cartilage loss and erosive damage in the hands and wrists. Investigations of the effects of drugs upon the radiological progression of rheumatoid arthritis include: indirect studies evaluating the inter-relationships between clinical, laboratory and radiological variables; placebo-controlled studies of slow-acting drugs and similarly controlled studies without a placebo group; open studies evaluating the long-term effects of treatment of slow-acting drugs. Only slow-acting drugs such as gold have been persistently considered to have a possible effect on reducing radiological progression. Unfortunately the therapeutic studies use a wide range of different radiological assessment techniques, and the incomparability is therefore difficult. None of the studies give a good indication that there is a marked reduction in joint damage by slow-acting drugs. On balance studies do suggest minor effects on the process of progression. Instead of debating how strong the evidence of such minor effect really is, it is concluded that rheumatologists should look towards novel therapeutic approaches to induce a major reduction in the rate of damage.

Controlled trial of hydroxychloroquine and D-penicillamine singly and in combination in the treatment of rheumatoid arthritis

A 2-year, controlled, double-blind trial of D-penicillamine and hydroxychloroquine either alone or in combination was conducted on patients with progressive rheumatoid arthritis. The group given D-penicillamine alone improved most, but a linear fall-off in efficacy occurred. Surprisingly, the group receiving combination drug therapy did not fare as well as the group receiving D-penicillamine therapy. A subset of patients receiving hydroxychloroquine therapy had prolonged benefit. Toxicity, though not uncommon, was generally not severe.

Progression of radiological changes in rheumatoid arthritis

A prospective study over one year of patients who had active rheumatoid arthritis discovered 64 who had received treatment for an adequate time with second-line drugs. In these patients there was evidence of continuing joint destruction as shown by radiological progression. During the year there were highly significant correlations between improvements in clinical and laboratory measurements, but neither group of tests was related to the degree of radiological change. However, in the second 6 months of treatment there was evidence that radiological progression was reduced. In a second prospective study of 88 patients with rheumatoid arthritis given prolonged, intensive therapy with second-line drugs and followed up for 10 years two-thirds showed radiological progression. However, the number of joints damaged per year fell significantly during the study period. There was a divergence between deterioration in radiological features and improvements in the ESR and functional capacity, though patients with a persistently low ESR had less radiological progression. These studies provide evidence that treatment may be associated with a reduced rate of radiological progression but suggest that changes in radiological progression and clinical and laboratory measurements may result from different mechanisms.

Does second-line therapy affect the radiological progression of rheumatoid arthritis?

The effect of 'second-line' drugs on radiological progression in rheumatoid arthritis is not clear, and previous studies have yielded contradictory results. Sixty-seven patients with rheumatoid arthritis have been followed up clinically and radiologically for approximately 2 years (26 patients were receiving intramuscular gold, 21 penicillamine, 10 levamisole, and there were 10 controls who had consistently refused second-line therapy). Patients on gold and penicillamine showed improvement in erythrocyte sedimentation rate and haemoglobin over 2 years which was not seen in levamisole and control patients, but hand radiograph scores in all 4 groups showed statistically significant deterioration. There was a trend towards slowing of the rate of erosion in the gold and penicillamine groups in comparison with controls, but healing of erosions was extremely unusual.

The relationship between aurothioglucose- and D-penicillamine-induced proteinuria

We studied patients with rheumatoid arthritis who have been treated with aurothioglucose (Au) and subsequently with D-penicillamine (DP), and who developed drug-induced proteinuria, over a 10-year period. Twelve patients developed Au-induced and 19 DP-induced proteinuria. Of the 12 patients with Au-induced proteinuria, only 2 (17%) developed DP-induced proteinuria, indicating a slightly increased risk as compared with the overall incidence (9.3%) of this reaction in 168 DP-treated patients. In addition, only a minority (2 out of 19, 10.6%) of patients with DP-induced proteinuria had previous Au-induced proteinuria. These data may indicate that different mechanisms are operative in Au and DP-induced proteinuria, as is also suggested by the finding that HLA-DR3 was present more frequently in the latter (50%) than in the former (21%). A history of previous Au-induced proteinuria is insufficient reason to deny these patients the benefits of subsequent treatment with DP.

Therapeutic progress--review VI. Treatment of rheumatoid arthritis

Anti-rheumatic drugs used in rheumatoid arthritis fall into two distinct groups: non-steroidal anti-inflammatory and second-line drugs. Non-steroidal anti-inflammatory drugs give early symptomatic improvement and reduce the degree of acute inflammatory synovitis. Second-line drugs such as gold or D penicillamine exert an anti-inflammatory effect only after two to three months and act by suppressing disease activity: these reduce the ESR and other acute phase responses. However, the evidence that any of these drugs halt the progression of radiological changes or can be used as long-term agents to control the disease over a period of years is weak. The current use of anti-rheumatic drugs follows a general pattern with non-steroidal anti-inflammatory drugs used alone in patients with mild disease, whereas patients with severe disease also receive second-line drugs. As yet the long-term effect of this policy is not known. Cytotoxic drugs should be restricted to patients with severe disease who either fail to respond to conventional second-line drugs or have active extra-articular disease, particularly those with vasculitis.