Influence of active versus placebo control on treatment responses in randomised controlled trials in rheumatoid arthritis

The impact of autoantibodies on the efficacy of biological disease-modifying anti-rheumatic drugs in rheumatoid arthritis: meta-analysis of randomized controlled trials

OBJECTIVE

To investigate the efficacy of bDMARDs in patients with RA with RF/ACPA compared with patients without these autoantibodies.

METHODS

Previous systematic literature reviews performed by EULAR RA management task forces were searched for qualifying RCTs. RCTs investigating the efficacy of bDMARDs and including both autoantibody-positive (≤80% of total population) and -negative RA patients were eligible. For trials comparing bDMARD+csDMARD vs csDMARD, relative risks (RR) comparing two groups (RF+ vs RF-, ACPA+ vs ACPA-) were calculated for efficacy outcomes for each arm. Subsequently, relative risk ratios (RRRs) were computed, as the ratio of RR of the bDMARD-arm and the RR from the non-bDMARD-arm. Pooled effects were obtained with random effect meta-analyses.

RESULTS

Data from 28 eligible RCTs were analysed, pooling 23 studies in three subgroups: six including csDMARD-naive patients, 14 csDMARD-IR and three TNFi-IR patients. In csDMARD-naive and csDMARD-IR patients, seropositivity was not associated with a better response to bDMARDs: pooled 6-month ACR20 RRRs 1.02 (0.88-1.18) and 1.09 (0.90-1.32), respectively. Other outcomes showed no difference between groups either. In TNFi-IR patients, based on three trials, the 6-month ACR20 RRR was 2.28 (1.31-3.95), favoring efficacy in seropositive patients. Other outcomes mostly showed no significant difference between the groups. Based on the mode of action, efficacy was comparable between RF-positive and RF-negative patients for both TNFi and non-TNFi treatment and also for the individual bDMARDs.

CONCLUSION

The effect of bDMARDs is generally comparable in patients with and without RF/ACPA, regardless of the patient population, the mechanism of action or individual drug used.

Influence of study characteristics on harm estimates from randomised controlled trials in patients with inflammatory arthritis receiving biological or synthetic antirheumatic drugs: a meta-epidemiological study

OBJECTIVE

To examine the association between study characteristics and the harms reported in randomised controlled trials (RCTs) on biological and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) in patients with inflammatory arthritis (IA).

METHODS

We searched MEDLINE for all Cochrane reviews and for systematic reviews published since April 2015. RCTs were eligible if they included patients with IA receiving b/tsDMARD, compared with any comparator arm. Harms were evaluated based on number of withdrawals due to adverse events (WDdtAEs), total withdrawals (WDs), serious adverse events (SAEs) and deaths. Data were extracted for 48 trial/patient characteristics and meta-regression analyses were performed to relate the relative risk ratio (RRR) of harms to the trial characteristics.

RESULTS

A total of 284 trials (from 245 reviews) with 97 607 patients were included, contributing 490 comparisons for the primary analysis. Overall, the relative risk of WDdtAEs was lower when trials used active comparators (RRR, 0.74 (95% CI 0.58 to 0.94)) and higher when requiring raised inflammatory markers at enrolment (RRR, 1.25 (1.01 to 1.55)). Our meta-regression analyses suggested that trials with eligibility criteria for minimum tender/swollen joint count and maximum disease duration decreased the risk of WDs, while previous b/tsDMARDs use at the time of enrolment increased the risk of SAEs.

CONCLUSIONS

Most study characteristics do not affect the reported harm measures. However, a trend was observed where trials selecting patients with higher baseline disease activity found a higher risk ratio of WDdtAEs and SAEs, but also a lower risk of WDs, compared with trials not selecting patients with a high disease activity.

PROSPERO REGISTRATION NUMBER

CRD42020171124.

Efficacy and safety of CT-P47 versus reference tocilizumab: 32-week results of a randomised, active-controlled, double-blind, phase III study in patients with rheumatoid arthritis, including 8 weeks of switching data from reference tocilizumab to CT-P47

OBJECTIVES

To demonstrate efficacy equivalence of CT-P47 and EU-approved reference tocilizumab (r-TCZ) in patients with rheumatoid arthritis (RA).

METHODS

This double-blind, phase III study randomised (1:1) patients to receive CT-P47 or r-TCZ (8 mg/kg) every 4 weeks until week 20 during treatment period (TP) 1. Prior to week 24 dosing, patients receiving r-TCZ were randomised (1:1) to continue r-TCZ or switch to CT-P47; patients receiving CT-P47 continued CT-P47 (TP2, 8 mg/kg every 4 weeks until week 48). The dual primary endpoints (for different regulatory requirements) were mean changes from baseline in Disease Activity Score in 28 joints (DAS28; erythrocyte sedimentation rate (ESR)) at week 12 and week 24. Efficacy equivalence was determined if CIs for the treatment difference were within predefined equivalence margins: (95% CI -0.6, 0.6 (analysis of covariance (ANCOVA)) at week 12 or 90% CI -0.6, 0.5 (ANCOVA with multiple imputation) at week 24). Additional efficacy, pharmacokinetic (PK) and safety endpoints, including immunogenicity, were investigated. Findings up to week 32 are presented.

RESULTS

In TP1, 471 patients were randomised (234 CT-P47; 237 r-TCZ). The 95% and 90% CIs for the estimated treatment differences were contained within the predefined equivalence margins; the estimated difference in DAS28-ESR at week 12 was -0.01 (95% CI -0.26, 0.24) and at week 24 was -0.10 (90% CI -0.30, 0.10). Secondary efficacy endpoints, PKs and overall safety were comparable between groups up to week 32.

CONCLUSIONS

Efficacy equivalence, alongside comparable PK, safety and immunogenicity profiles, was determined between CT-P47 and r-TCZ in adults with RA, including after switching from r-TCZ to CT-P47.

Patterns and determinants of response to novel therapies in juvenile and adult-onset polyarthritis

Biologic and targeted synthetic DMARDs (b/tsDMARDs) have revolutionized the management of multiple rheumatic inflammatory conditions. Among these, polyarticular JIA (pJIA) and RA display similarities in terms of disease pathophysiology and response pattern to b/tsDMARDs. Indeed, the therapeutic efficacy of novel targeted drugs is variable among individual patients, in both RA and pJIA. The mechanisms and determinants of this heterogeneous response are diverse and complex, such that the development of true 'precision'-medicine strategies has proven highly challenging. In this review, we will discuss pathophysiological, patient-specific, drug-specific and environmental factors contributing to individual therapeutic response in pJIA in comparison with what is known in RA. Although some biomarkers have been identified that stratify with respect to the likelihood of either therapeutic response or non-response, few have proved useful in clinical practice so far, likely due to the complexity of treatment-response mechanisms. Consequently, we propose a pragmatic, patient-centred and clinically based approach, i.e. personalized instead of biomarker-based precision medicine in JIA.

Why most (but perhaps not all) DMARDs work equally well

Biological- or targeted-synthetic DMARD-responses reported in randomized clinical trials, placebo-controlled or head-to-head, in patients with rheumatoid arthritis, psoriatic arthritis or spondyloarthritis are unbelievably similar, when looking across trials performed in the same disease and applying the same primary outcome measures. The exception to this rule may be the response to Janus-kinase-inhibitors, which seem to work 10 % better in all trials (JAK-bonus) This article provides a potential explanation for this remarkable phenomenon, including an explanation for the JAK-bonus. It seems as if JAK-inhibitors exert some inflammation-independent effects on pain, fatigue and wellbeing, and that drug treatment of rheumatic diseases is more than the inhibition of inflammation alone.

Determination of the most appropriate ACR response definition for contemporary drug approval trials in rheumatoid arthritis

OBJECTIVES

To evaluate which American College of Rheumatology (ACR) response definition (ACR20, 50 or 70) should primarily be used for efficacy claims in future drug approval trials of rheumatoid arthritis (RA).

METHODS

We systematically searched EMBASE, Medline and the Cochrane Library for randomised controlled RA drug approval trials of biological and targeted synthetic disease-modifying antirheumatic drugs (DMARDs). We included full-text articles reporting ACR response rates for multiple time points over a 24-week placebo-controlled period and visualised normalised response trajectories over time in different patient populations. Using mixed-effect logistic regression, we calculated the proportion of ACR responders per outcome and time point, and compared the discriminant validity of these metrics at multiple time points.

RESULTS

We screened 12 680 records and included 45 in the final analysis. Discriminative capacity of the ACR20 was high across all time points, whereas ACR50 and ACR70 showed highest discrimination towards the end of the placebo-controlled periods. This effect could be observed in all patient populations and compound groups. Faster response to treatment was observed in DMARD naïve patient populations when compared with DMARD insufficient responders.

CONCLUSION

ACR20 remains the most powerful discriminator between active treatment and placebo, especially when early discrimination is of primary interest. At the same time, our results support the selection of more stringent thresholds if later time points shall be evaluated, given their comparable discriminant but higher clinical face validity.

Why do drug treatments fail in Sjögren's disease? Considerations for treatment, trial design and interpretation of clinical efficacy

INTRODUCTION

Despite ongoing efforts to develop effective therapeutics, no disease-modifying drugs have been officially licensed for the indication of Sjögren's disease (SjD). This is partly due to heterogeneity in disease manifestations, which complicates drug target selection, trial design and interpretation of clinical efficacy in SjD.

AREAS COVERED

Here, we summarize developments and comment on challenges in 1) identifying the right target for treatment, 2) selection of the primary study endpoint for trials and definition of clinically relevant response to treatment, 3) inclusion criteria and patient stratification, 4) distinguishing between disease activity and damage and 5) establishing the effect of treatment considering measurement error, natural variation, and placebo or nocebo responses.

EXPERT OPINION

Targets that are involved in both the immune cell response and dysregulation of glandular epithelial cells (e.g. B-lymphocytes, type-I interferon) are of particular interest to treat both glandular and extra-glandular manifestations of SjD. The recent development of composite study endpoints (CRESS and STAR) may be a crucial step forward in the search for clinically effective systemic treatment of patients with SjD. Important additional areas for future research are symptom-based and/or molecular pathway-based patient stratification, prevention of irreversible damage, and establishing the effect of treatment.