Clinical and radiologic analysis of on-demand use of etanercept for disease flares in patients with rheumatoid arthritis for 2 years: The RESUME study: A case-control study

Use of external control arms in immune-mediated inflammatory diseases: a systematic review

OBJECTIVES

External control arms (ECAs) provide useful comparisons in clinical trials when randomised control arms are limited or not feasible. We conducted a systematic review to summarise applications of ECAs in trials of immune-mediated inflammatory diseases (IMIDs).

DESIGN

Systematic review with an appraisal of ECA source quality rated across five domains (data collection, study populations, outcome definitions, reliability and comprehensiveness of the dataset, and other potential limitations) as high, low or unclear quality.

DATA SOURCES

Embase, Medline and Cochrane Central Register of Controlled Trial were searched through to 12 September 2023.

ELIGIBILITY CRITERIA

Eligible studies were single-arm or randomised controlled trials (RCTs) of inflammatory bowel disease, pouchitis, rheumatoid arthritis, juvenile idiopathic arthritis, ankylosing spondylitis, psoriatic arthritis, psoriasis and atopic dermatitis in which an ECA was used as the comparator.

DATA EXTRACTION AND SYNTHESIS

Two authors independently screened the search results in duplicate. The characteristics of included studies, external data source(s), outcomes and statistical methods were recorded, and the quality of the ECA data source was assessed by two independent authors.

RESULTS

Forty-three studies met the inclusion criteria (inflammatory bowel disease: 16, pouchitis: 1, rheumatoid arthritis: 12, juvenile idiopathic arthritis: 1, ankylosing spondylitis: 5, psoriasis: 3, multiple indications: 4). The majority of these trials were single-arm (33/43) and enrolled adult patients (34/43). All included studies used a historical control rather than a contemporaneous ECA. In RCTs, ECAs were most often derived from the placebo arm of another RCT (6/10). In single-arm trials, historical case series were the most common ECA source (19/33). Most studies (31/43) did not employ a statistical approach to generate the ECA from historical data.

CONCLUSIONS

Standardised ECA methodology and reporting conventions are lacking for IMIDs trials. The establishment of ECA reporting guidelines may enhance the rigour and transparency of future research.

Prevalence and predictors of sustained remission/low disease activity after discontinuation of induction or maintenance treatment with tumor necrosis factor inhibitors in rheumatoid arthritis: a systematic and scoping review

BACKGROUND

To determine the prevalence of sustained remission/low disease activity (LDA) in patients with rheumatoid arthritis (RA) after discontinuation of tumor necrosis factor inhibitors (TNFi), separately in induction treatment and maintenance treatment studies, and to identify predictors of successful discontinuation.

METHODS

We performed a systematic literature review of studies published from 2005 to May 2022 that reported outcomes after TNFi discontinuation among patients in remission/LDA. We computed prevalences of successful discontinuation by induction or maintenance treatment, remission criterion, and follow-up time. We performed a scoping review of predictors of successful discontinuation.

RESULTS

Twenty-two induction-withdrawal studies were identified. In pooled analyses, 58% (95% confidence interval (CI) 45, 70) had DAS28 < 3.2 (9 studies), 52% (95% CI 35, 69) had DAS28 < 2.6 (9 studies), and 40% (95% CI 18, 64) had SDAI ≤ 3.3 (4 studies) at 37-52 weeks after discontinuation. Among patients who continued TNFi, 62 to 85% maintained remission. Twenty-two studies of maintenance treatment discontinuation were also identified. At 37-52 weeks after TNFi discontinuation, 48% (95% CI 38, 59) had DAS28 < 3.2 (10 studies), and 47% (95% CI 33, 62) had DAS28 < 2.6 (6 studies). Heterogeneity among studies was high. Data on predictors in induction-withdrawal studies were limited. In both treatment scenarios, longer duration of RA was most consistently associated with less successful discontinuation.

CONCLUSIONS

Approximately one-half of patients with RA remain in remission/LDA for up to 1 year after TNFi discontinuation, with slightly higher proportions in induction-withdrawal settings than with maintenance treatment discontinuation.

Cost-Effectiveness Analysis of Etanercept 25 mg Maintenance Therapy After Treatment with Etanercept 50 mg for Moderate Rheumatoid Arthritis in the PRESERVE Trial in Japan

OBJECTIVES

To use Markov modeling to estimate the cost-effectiveness of treatment with etanercept 25 mg once weekly plus methotrexate (MTX) in Japanese patients with rheumatoid arthritis who had achieved remission or low disease activity with etanercept 50 mg once weekly plus MTX.

METHODS

Effectiveness data were estimated based on results from a clinical trial (PRESERVE) in patients with rheumatoid arthritis who had achieved remission or low disease activity and who were then randomized to receive etanercept 25 mg plus MTX or placebo plus MTX. A Markov model was established and included flare rates of 21% and 62% in the etanercept 25 mg and placebo groups, respectively. EQ-5D was calculated using an ordinary least-squares model that included the health assessment questionnaire disability index and pain visual analog scale. Worsening of the health assessment questionnaire score over 1 year was estimated to be 0.047 for patients with flare, and when associated with radiographic progression it was estimated to increase by 0.006 and 0.025 in the etanercept 25 mg and placebo groups, respectively. A cycle length of 1 year was applied to calculate the cumulative cost and effectiveness for a 10-year time span.

RESULTS

Compared with the placebo group, the quality-adjusted life-years for the etanercept 25 mg group was increased by 0.841. The incremental cost-effectiveness ratio was ¥6 173 772.

CONCLUSION

These results suggest that maintenance treatment with etanercept 25 mg is cost-effective.