Rheumatoid Arthritis: McCabe D

Camp NJ, Cox A, di Giovine FS, McCabe D, Rich W, Duff GW. · Division of Genomic Medicine, University of Sheffield, UK. · Genes Immun. · Pubmed #15931231 No free full text.

Abstract: Biological activity of the IL-1 system depends on the balance between two proinflammatory proteins (IL-1alpha and IL-1beta) and the related anti-inflammatory protein, the IL-1 receptor antagonist (IL-1Ra). The genes for these proteins lie within 430 kb on human chromosome 2. Based on a clinical trial of human recombinant IL-1ra in rheumatoid arthritis, we tested whether IL-1 genotype might be related to the likelihood of response to anti-IL-1 therapy. A positive response was defined as a reduction of at least 50% in the number of swollen joints by week 24, following treatment with either 150 mg/day IL-1ra or placebo. The response rate to treatment, independent of genotype, was 48% (44/91). A highly significant association was found between carriage of the rarer allele at IL1A(+4845) and response to treatment (P=0.0009; OR=4.85 (1.85,12.70)). The response rate in patients carrying this allele was 63.4% compared with 26.3% in noncarriers. A weaker association was found for IL1B(+3954) (P=0.02). There was a highly significant interaction between treatment (150 mg/day or placebo) and the composite genotype across IL1A(+4845) and IL1B(+3954) (P=7.6 x 10(-5)). No associations with IL-1 genotypes were found in patients receiving placebo. Thus, a significant pharmacogenomic effect was found in the treatment of RA patients with recombinant IL-1ra.

Nuki G, Bresnihan B, Bear MB, McCabe D, Anonymous00113. · University of Edinburgh, Edinburgh, Scotland, UK. · Arthritis Rheum. · Pubmed #12428223 links to  free full text

Abstract: OBJECTIVE: To demonstrate the long-term efficacy of anakinra, a human recombinant interleukin-1 receptor antagonist, in patients with rheumatoid arthritis (RA), and to assess the long-term safety of anakinra at different daily doses. METHODS: The efficacy and safety of anakinra were previously demonstrated in a double-blind, placebo-controlled, 24-week evaluation in 472 patients with active RA. Of 345 patients who completed the placebo-controlled phase of the study, 309 continued in a 52-week, multicenter, double-blind, parallel-group extension phase of the study. Patients received subcutaneous injections of anakinra (30, 75, or 150 mg) once daily. Efficacy was assessed among the 309 patients for the first 24 weeks of the extension phase (48 weeks total therapy), using the American College of Rheumatology composite score (ACR20), its components, and radiographs of the hands and wrists. Safety was assessed in all 472 patients over the entire 52-week extension phase (76 weeks total exposure). RESULTS: A total of 218 patients completed the extension phase. Of the 91 patients who withdrew prematurely, 46 did so following adverse events, and 26 withdrew because of lack of efficacy. Among patients receiving anakinra who entered the extension phase, the level of improvement was maintained for 48 weeks. The ACR20 response was 51% at week 24 and 46% at week 48, and this effect was consistent across all dose groups. The durability of the response to anakinra was further demonstrated in an evaluation of the sustained ACR20 response, which was similar during the first and second 24-week periods (36% and 42%, respectively). At week 48, ACR50 and ACR70 responses were demonstrated in 18% and 3% of patients, respectively, who continued taking anakinra (all dose groups) and in 20% and 1% of patients, respectively, who were originally receiving placebo and then were randomized to all doses of anakinra. Anakinra was well tolerated for 76 weeks. The only side effects that appeared to be treatment-related were skin reactions at the injection site. There was no evidence of decreased tolerance, an increased number of withdrawals, or an increased incidence of clinical complications associated with extended anakinra therapy. CONCLUSION: The clinical benefits of treatment with daily self-administered subcutaneous injections of anakinra in a cohort of patients with active RA were maintained for up to 48 weeks. Anakinra was well tolerated over 76 weeks. These observations support the long-term use of anakinra for the treatment of patients with RA.

Cohen S, Hurd E, Cush J, Schiff M, Weinblatt ME, Moreland LW, Kremer J, Bear MB, Rich WJ, McCabe D. · Department of Rheumatology, St. Paul Medical Center, Dallas, Texas 75235, USA. · Arthritis Rheum. · Pubmed #11920396 links to  free full text

Abstract: OBJECTIVE: To evaluate the efficacy and safety of anakinra in combination with methotrexate (MTX) in patients with active rheumatoid arthritis (RA). METHODS: Patients with moderate-to-severe active RA who were receiving MTX for 6 consecutive months, with stable doses for > or = 3 months (those with disease duration of >6 months but <12 years) were randomized into 6 groups: placebo or 0.04, 0.1, 0.4, 1.0, or 2.0 mg/kg of anakinra administered in a single, daily, subcutaneous injection. The primary efficacy end point was the proportion of subjects who met the American College of Rheumatology 20% improvement criteria (attained an ACR20 response) at week 12. RESULTS: A total of 419 patients were randomized in the study. Patient demographics and disease status were similar in the 6 treatment groups. The ACR20 responses at week 12 in the 5 active treatment plus MTX groups demonstrated a statistically significant (P = 0.001) dose-response relationship compared with the ACR20 response in the placebo plus MTX group. The ACR20 response rate in the anakinra 1.0-mg/kg (46%; P = 0.001) and 2.0-mg/kg (38%; P = 0.007) dose groups was significantly greater than that in the placebo group (19%). The ACR20 responses at 24 weeks were consistent with those at 12 weeks. Similar improvements in anakinra-treated subjects were noted in individual ACR components, erythrocyte sedimentation rate, onset of ACR20 response, sustainability of ACR20 response, and magnitude of ACR response. Anakinra was safe and well tolerated. Injection site reaction was the most frequently noted adverse event, and this led to premature study withdrawal in 7% (1.0-mg/kg group) to 10% (2.0-mg/kg group) of patients receiving higher doses. CONCLUSION: In patients with persistently active RA, the combination of anakinra and MTX was safe and well tolerated and provided significantly greater clinical benefit than MTX alone.

Jiang Y, Genant HK, Watt I, Cobby M, Bresnihan B, Aitchison R, McCabe D. · University of California, San Francisco 94143-0628, USA. · Arthritis Rheum. · Pubmed #10817552 links to  free full text

Abstract: OBJECTIVE: To evaluate radiographic progression and the relationship of radiologic scores obtained by the Genant and Larsen methods in a clinical trial of recombinant human interleukin-1 receptor antagonist (IL-1Ra). METHODS: Patients with rheumatoid arthritis (RA) were randomized into 4 groups: placebo (n = 121) or IL-1Ra at a daily dosage of 30 mg (n = 119), 75 mg (n = 116), or 150 mg (n = 116). Hand radiographs obtained at baseline, 24 weeks, and 48 weeks were scored using both methods. RESULTS: At 24 weeks, by the Genant method, there was significant reduction in the score for progression of joint space narrowing (JSN) and the total score (a combination of erosion and JSN) in all treatment groups. Least-squares mean changes in the Genant erosion score from baseline to 24 weeks were significantly reduced after treatment with IL-1Ra at 30 mg/day and for all IL-1Ra treatment groups combined. The changes corresponded to a reduction of 38% in erosion, 58% in JSN, and 47% in total score. Patients treated with IL-1Ra at 75 mg/day had a significant reduction in the Larsen erosive joint count (LEJC), and all IL-1RA-treated groups combined showed a 45% reduction. Correlations (r) between the Genant total and Larsen scores were 0.84 at baseline, 0.83 at week 24, and 0.83 at week 48 (P < 0.0001); correlations between the Genant erosion score and the LEJC were 0.83 (P < 0.0001) at all visits; correlations between the Genant total and the Larsen scores were 0.32 and 0.49 (P < 0.0001) for progression from baseline to week 24 and from baseline to week 48, respectively; correlations between the Genant erosion score and the LEJC were 0.36 and 0.41 (P < 0.0001) for progression to weeks 24 and 48, respectively. CONCLUSION: IL-1Ra reduced radiologic progression of RA. Scores by the 2 methods correlated strongly for each individual time point, but much less strongly for assessments of disease progression.

Bendele A, McAbee T, Sennello G, Frazier J, Chlipala E, McCabe D. · Amgen Inc., Thousand Oaks, California 91320-1789, USA. · Arthritis Rheum. · Pubmed #10088773 links to  free full text

Abstract: OBJECTIVE: To determine the role of interleukin-1 receptor antagonist (IL-1Ra) in rat adjuvant arthritis and rat type II collagen-induced arthritis, and to compare the efficacy in rat models with that seen in human clinical trials of IL-1Ra. METHODS: Rats with developing adjuvant arthritis or established collagen-induced arthritis were treated with IL-1Ra by continuous infusion in order to determine and maintain efficacious blood levels of this IL-1 inhibitory protein in the rats for comparison with human clinical data. The effects of treatment in the rats were monitored by sequential caliper measurement of the ankle joints, determination of final paw weights, and histologic evaluation with particular emphasis on bone and cartilage lesions. The effects of IL-1Ra on joint swelling and radiographic bone damage in patients with rheumatoid arthritis (RA) in a 6-month trial were compared with the findings in rats. RESULTS: Dramatic differences in the profile of IL-1Ra activity were seen between the 2 groups of rats. Modest antiinflammatory effects were observed in the adjuvant arthritis rats treated with IL-1Ra. However, marked inhibition of bone resorption occurred, even at doses with which antiinflammatory activity was not seen. In contrast, IL-1Ra treatment of rats with established collagen-induced arthritis resulted in nearly complete suppression of all aspects of the disease when adequate blood levels of IL-1Ra were maintained. Treatment of RA patients with IL-1Ra (150 mg daily) resulted in modest inhibition of joint swelling and inhibition of radiographic progression of bone lesions. CONCLUSION: IL-1 appears to be of major importance in mediating the bone resorption that occurs in rat adjuvant arthritis, but is less important in the pathogenesis of periarticular inflammation in this disease. In contrast, IL-1 is of major importance in mediating all aspects of disease progression in rat collagen-induced arthritis. Similar to the response in adjuvant arthritic rats, RA patients treated with IL-1Ra showed only modest antiinflammatory activity, but had evidence of inhibition of progression of bone resorption. However, a comparison of the plasma levels of IL-1Ra in humans and rats suggests that the optimal level of dosing for continuous saturation of IL-1 receptors may not have been achieved in humans, although this was achieved in the rat studies.