Background: Biologic disease-modifying anti-rheumatic drugs (DMARDs: referred to as biologics) are effective in treating rheumatoid arthritis (RA), however there are few head-to-head comparison studies. Our systematic review, standard meta-analysis and network meta-analysis (NMA) updates the 2009 Cochrane overview, 'Biologics for rheumatoid arthritis (RA)' and adds new data. This review is focused on biologic or tofacitinib therapy in people with RA who had previously been treated unsuccessfully with biologics.
Objectives: To compare the benefits and harms of biologics (abatacept, adalimumab, anakinra, certolizumab pegol, etanercept, golimumab, infliximab, rituximab, tocilizumab) and small molecule tofacitinib versus comparator (placebo or methotrexate (MTX)/other DMARDs) in people with RA, previously unsuccessfully treated with biologics.
Methods: On 22 June 2015 we searched for randomized controlled trials (RCTs) in CENTRAL, MEDLINE, and Embase; and trials registries (WHO trials register, Clinicaltrials.gov). We carried out article selection, data extraction, and risk of bias and GRADE assessments in duplicate. We calculated direct estimates with 95% confidence intervals (CI) using standard meta-analysis. We used a Bayesian mixed treatment comparison (MTC) approach for NMA estimates with 95% credible intervals (CrI). We converted odds ratios (OR) to risk ratios (RR) for ease of understanding. We have also presented results in absolute measures as risk difference (RD) and number needed to treat for an additional beneficial outcome (NNTB). Outcomes measured included four benefits (ACR50, function measured by Health Assessment Questionnaire (HAQ) score, remission defined as DAS < 1.6 or DAS28 < 2.6, slowing of radiographic progression) and three harms (withdrawals due to adverse events, serious adverse events, and cancer).
Main results: This update includes nine new RCTs for a total of 12 RCTs that included 3364 participants. The comparator was placebo only in three RCTs (548 participants), MTX or other traditional DMARD in six RCTs (2468 participants), and another biologic in three RCTs (348 participants). Data were available for four tumor necrosis factor (TNF)-biologics: (certolizumab pegol (1 study; 37 participants), etanercept (3 studies; 348 participants), golimumab (1 study; 461 participants), infliximab (1 study; 27 participants)), three non-TNF biologics (abatacept (3 studies; 632 participants), rituximab (2 studies; 1019 participants), and tocilizumab (2 studies; 589 participants)); there was only one study for tofacitinib (399 participants). The majority of the trials (10/12) lasted less than 12 months.We judged 33% of the studies at low risk of bias for allocation sequence generation, allocation concealment and blinding, 25% had low risk of bias for attrition, 92% were at unclear risk for selective reporting; and 92% had low risk of bias for major baseline imbalance. We downgraded the quality of the evidence for most outcomes to moderate or low due to study limitations, heterogeneity, or rarity of direct comparator trials. Biologic monotherapy versus placeboCompared to placebo, biologics were associated with clinically meaningful and statistically significant improvement in RA as demonstrated by higher ACR50 and RA remission rates. RR was 4.10 for ACR50 (95% CI 1.97 to 8.55; moderate-quality evidence); absolute benefit RD 14% (95% CI 6% to 21%); and NNTB = 8 (95% CI 4 to 23). RR for RA remission was 13.51 (95% CI 1.85 to 98.45, one study available; moderate-quality evidence); absolute benefit RD 9% (95% CI 5% to 13%); and NNTB = 11 (95% CI 3 to 136). Results for withdrawals due to adverse events and serious adverse events did not show any statistically significant or clinically meaningful differences. There were no studies available for analysis for function measured by HAQ, radiographic progression, or cancer outcomes. There were not enough data for any of the outcomes to look at subgroups. Biologic + MTX versus active comparator (MTX/other traditional DMARDs)Compared to MTX/other traditional DMARDs, biologic + MTX was associated with a clinically meaningful and statistically significant improvement in ACR50, function measured by HAQ, and RA remission rates in direct comparisons. RR for ACR50 was 4.07 (95% CI 2.76 to 5.99; high-quality evidence); absolute benefit RD 16% (10% to 21%); NNTB = 7 (95% CI 5 to 11). HAQ scores showed an improvement with a mean difference (MD) of 0.29 (95% CI 0.21 to 0.36; high-quality evidence); absolute benefit RD 9.7% improvement (95% CI 7% to 12%); and NNTB = 5 (95% CI 4 to 7). Remission rates showed an improved RR of 20.73 (95% CI 4.13 to 104.16; moderate-quality evidence); absolute benefit RD 10% (95% CI 8% to 13%); and NNTB = 17 (95% CI 4 to 96), among the biologic + MTX group compared to MTX/other DMARDs. There were no studies for radiographic progression. Results were not clinically meaningful or statistically significantly different for withdrawals due to adverse events or serious adverse events, and were inconclusive for cancer. Tofacitinib monotherapy versus placeboThere were no published data. Tofacitinib + MTX versus active comparator (MTX)In one study, compared to MTX, tofacitinib + MTX was associated with a clinically meaningful and statistically significant improvement in ACR50 (RR 3.24; 95% CI 1.78 to 5.89; absolute benefit RD 19% (95% CI 12% to 26%); NNTB = 6 (95% CI 3 to 14); moderate-quality evidence), and function measured by HAQ, MD 0.27 improvement (95% CI 0.14 to 0.39); absolute benefit RD 9% (95% CI 4.7% to 13%), NNTB = 5 (95% CI 4 to 10); high-quality evidence). RA remission rates were not statistically significantly different but the observed difference may be clinically meaningful (RR 15.44 (95% CI 0.93 to 256.1; high-quality evidence); absolute benefit RD 6% (95% CI 3% to 9%); NNTB could not be calculated. There were no studies for radiographic progression. There were no statistically significant or clinically meaningful differences for withdrawals due to adverse events and serious adverse events, and results were inconclusive for cancer.
Authors' conclusions: Biologic (with or without MTX) or tofacitinib (with MTX) use was associated with clinically meaningful and statistically significant benefits (ACR50, HAQ, remission) compared to placebo or an active comparator (MTX/other traditional DMARDs) among people with RA previously unsuccessfully treated with biologics.No studies examined radiographic progression. Results were not clinically meaningful or statistically significant for withdrawals due to adverse events and serious adverse events, and were inconclusive for cancer.