Efficacy, safety, pharmacokinetics and immunogenicity of abatacept administered subcutaneously or intravenously in Japanese patients with rheumatoid arthritis and inadequate response to methotrexate: a Phase II/III, randomized study

Assessing Immunogenicity of Biologic Drugs in Inflammatory Joint Diseases: Progress Towards Personalized Medicine

Biologic drugs have greatly improved treatment outcomes of inflammatory joint diseases, but a substantial proportion of patients either do not respond to treatment or lose response over time. Drug immunogenicity, manifested as the formation of anti-drug antibodies (ADAb), constitute a significant clinical problem. Anti-drug antibodies influence the pharmacokinetics of the drug, are associated with reduced clinical efficacy, and an increased risk of adverse events such as infusion reactions. The prevalence of ADAb differs among drugs and diseases, and the detection of ADAb also depends on the assay format. Most data exist for the tumor necrosis factor-alpha inhibitors infliximab and adalimumab, with a frequency of ADAb that ranges from 10 to 60% across studies. Measurement of ADAb and serum drug concentrations, therapeutic drug monitoring, has been suggested as a strategy to optimize therapy with biologic drugs. Although the recent randomized clinical Norwegian Drug Monitoring (NOR-DRUM) trials show promise towards a personalized medicine prescribing approach by therapeutic drug monitoring, several challenges remain. A plethora of assay formats, with widely differing properties, is currently used for measuring ADAb. Comparing results between different assays and laboratories is difficult, which complicates the development of cut-offs necessary for guidelines and the implementation of ADAb measurements in clinical practice. With the possible exception of infliximab, limited data on clinical relevance and cost effectiveness exist to support therapeutic drug monitoring as a routine clinical strategy to monitor biologic drugs in inflammatory joint diseases. The aim of this review is to provide an overview of the characteristics and prevalence of ADAb, predisposing factors to ADAb formation, commonly used assessment methods, clinical consequences of ADAb, and the potential implications of ADAb assessments for everyday treatment of inflammatory joint diseases.

Therapeutic drug monitoring of biopharmaceuticals in inflammatory rheumatic and musculoskeletal disease: a systematic literature review informing EULAR points to consider

The objectives of this review were to collect and summarise evidence on therapeutic drug monitoring (TDM) of biopharmaceuticals in inflammatory rheumatic and musculoskeletal diseases and to inform the EULAR Task Force for the formulation of evidence-based points to consider. A systematic literature review (SLR) was performed, covering technical aspects and (clinical) utility of TDM, to answer 13 research questions. MEDLINE, Embase and Cochrane were searched until July 2020. American College of Rheumatology and EULAR abstracts were also considered for inclusion. Data were extracted in evidence tables and risk of bias assessment was performed. For the search on technical aspects, 678 records were identified, of which 22 papers were selected. For the clinical utility search, 3846 records were identified, of which 108 papers were included. Patient-related factors associated with biopharmaceutical blood concentrations included body weight, methotrexate comedication and disease activity. The identification of a target range was hampered by study variability, mainly disease activity measures and study type. Evidence was inconsistent for multiple clinical situations in which TDM is currently applied. However, for some particular scenarios, including prediction of future treatment response, non-response to treatment, tapering and hypersensitivity reactions, robust evidence was found. There is currently no evidence for routine use of proactive TDM, in part because published cost-effectiveness analyses do not incorporate the current landscape of biopharmaceutical costs and usage. This SLR yields evidence in favour of TDM of biopharmaceuticals in some clinical scenarios, but evidence is insufficient to support implementation of routine use of TDM.

Differences in patients' population and efficacy/effectiveness of biologic disease-modifying antirheumatic drugs between randomized controlled trials and real-world settings in patients with rheumatoid arthritis - using the IORRA cohort

OBJECTIVES

To evaluate the differences in patients' population and efficacy/effectiveness of biological disease-modifying antirheumatic drugs (bDMARDs) between randomized controlled trials (RCTs) and clinical practice in patients with rheumatoid arthritis.

METHODS

We reviewed inclusion criteria in Phase II or III RCTs of bDMARDs conducted in Japan. The Institute of Rheumatology, Rheumatoid Arthritis study participants during the period when each RCT was conducted (Cohort A) and new bDMARD users at our institute in 2016 (Cohort B) were assessed for the fulfilment of the inclusion criteria. The effectiveness of bDMARDs in our cohort and their efficacy in RCTs were compared using the inverse-variance method.

RESULTS

Nineteen RCTs were selected. The mean proportions of patients fulfilling all inclusion criteria of each RCT in Cohorts A and B were 2.3% and 7.6%, respectively. The pooled proportion ratios (95% confidence interval) for achieving the American College of Rheumatology 20 (ACR20), ACR50, ACR70, and disease activity score 28 remission in non-eligible cases for eight RCTs versus all corresponding RCTs were 0.38 (0.30-0.51), 0.41 (0.30-0.57), 0.54 (0.35-0.82), and 1.28 (1.10-1.56), respectively.

CONCLUSIONS

Few rheumatoid arthritis patients fulfilled the inclusion criteria of the RCTs in clinical settings. There was a difference in the efficacy/effectiveness of bDMARDs between RCTs and clinical practice.

Model-Based Selection and Recommendation for Subcutaneous Abatacept Dose in Patients With Polyarticular Juvenile Idiopathic Arthritis

The selective T‐cell costimulation modulator abatacept is approved for treatment of adult rheumatoid arthritis (RA) and polyarticular juvenile idiopathic arthritis (pJIA; 6‐17 years [intravenous] and 2‐17 years [subcutaneous]). An extrapolation approach was taken to determine subcutaneous weight‐tiered doses of abatacept to evaluate in patients with pJIA. Population pharmacokinetic (PPK) and exposure‐response (E‐R) analyses were conducted to determine whether the weight‐tiered subcutaneous regimen provides near‐maximal efficacy and is therapeutically comparable to the intravenous regimen in patients with pJIA aged 2‐17 years. Combined study data from intravenous or subcutaneous abatacept were used to assess clinically relevant exposure outcomes. The PPK model was developed with data from 13 phase 2/3 studies in RA and pJIA; the E‐R model for the American College of Rheumatology pediatric scores (JIA‐ACR 30/50/70/100 responses) in month 4 was developed with data from 2 phase 3 pJIA studies. Predefined covariates were investigated in both analyses. PPK model‐predicted exposures were steady‐state peak, trough (C_minss), and time‐averaged concentrations. Abatacept PK was characterized by a linear 2‐compartment model (zero‐order intravenous infusion, first‐order subcutaneous absorption, first‐order elimination); body weight was the only clinically relevant covariate. C_minss was the best exposure predictor for the JIA‐ACR response: log odds for response increased in proportion to log‐transformed C_minss; JIA‐ACR30 approached a plateau when C_minss ≥ 10 μg/mL. The PPK and E‐R analyses demonstrated that the weight‐tiered subcutaneous and intravenous abatacept dosing regimens provide near‐maximal efficacy and are clinically comparable across children with pJIA who are > 2 years old.

CTLA4-Ig (abatacept): a promising investigational drug for use in type 1 diabetes

Introduction: Type 1 diabetes (T1D) is an autoimmune disease that results from the destruction of insulin-producing beta cells in the pancreas; it leads to the under or nonproduction of insulin. T1D is associated with numerous life-threatening micro- and macro-vascular complications and early deaths, hence the development of preventative strategies is a priority for research.Areas covered: The authors outline the drawbacks of available treatments for T1D and assess the three key strategies for prevention, including immunomodulatory therapies which hold the most potential. This article examines CTLA4-Ig and its efficacy and safety profiles. Finally, the pharmacokinetic parameters and pharmacodynamic markers of abatacept are shown in vivo and in clinical trials, guiding dosage regimen recommendations for future investigational studies.Expert opinion: Immunomodulation is one of the promising strategies for decelerating the progression of beta-cell destruction after the onset of T1D. It holds the advantage of specific immune modulation without systemic general immunosuppression. Preclinical and clinical studies have yielded promising data on the use of CTLA4-Ig in T1D. Variations in response to CTLA4-Ig might be partially explained by the existence of multiple T1D subtypes with varying baseline innate inflammatory/regulatory bias and the rate of C-peptide decline.

Multicenter, observational clinical study of abatacept in Japanese patients with rheumatoid arthritis

The aim of this study was to assess abatacept in rheumatoid arthritis (RA) patient. Patients (20 men, 89 women, aged 61.9 ± 10.4 y) who responded inadequately to conventional synthetic disease-modifying anti-rheumatic drug were treated with abatacept for 24-months. Disease activity score in 28 joints (DAS28-CRP) was evaluated. Of 109 patients, 82 (75.2%) were on methotrexate (MTX; mean dosage 9.0 ± 2.7 mg/week); 48 (44.0%) were naive to biologics and 61 (56.0%) had failed biologics. The 1- and 2-year retention rates were 77% and 53%, respectively. At 24-months, the DAS28-CRP remission rates were 54.5% in the biologic-naïve patients, and 28.2% in the biologic-failure patients (p < .01), while the structural remission rates were 83.9% and 73.1%, respectively (p = .461). Abatacept was equally effective in RA patients who were and were not on concomitant MTX. Biologic-naïve was associated with better clinical outcome. Abatacept was effective in patients who showed decreasing anti-CCP antibody titers or serum MMP-3 levels during treatment. Infection was the most frequent adverse effect of abatacept therapy. In conclusion, abatacept is more effective in biologic-naïve than in biologic-failure RA patients with or without concomitant use of MTX. Abatacept is more effective in RA patients with than without decreasing serum MMP-3 or anti-CCP antibody titers during treatment.

The in vitro effect of antirheumatic drugs on platelet function

Several antirheumatic drugs lower the cardiovascular risk among rheumatoid arthritis patients. It is, however, unknown whether inhibition of platelet function contributes to this risk reduction. Only few studies have investigated the potential role of platelets as a target of antirheumatic drugs. In this study, platelet function was tested in vitro in samples from 24 healthy individuals spiked with antirheumatic drugs in clinically relevant concentrations or vehicle. Platelet aggregation was tested with 96-well light transmission aggregometry (LTA), and when an effect ≥20% compared to vehicle was observed, flow cytometric platelet aggregation and activation were evaluated and closure time was measured by Platelet Function Analyzer (PFA-200). When evaluated by LTA, teriflunomide (the active metabolite of leflunomide), tocilizumab, and prednisolone reduced ADP- and collagen-induced platelet aggregation ≥20%, while adalimumab increased TRAP-induced platelet aggregation ≥20%. Using flow cytometry, agonist-induced platelet aggregation with teriflunomide or vehicle was mean ± standard deviation (SD); 30.7% ± 5.8 vs. 41.7% ± 6.5, p = 0.02 using ADP, and 34.7% ± 13.9 vs. 55.8% ± 3.9, p = 0.01 using collagen. Results indicate that teriflunomide, prednisolone, and tocilizumab inhibit, and adalimumab increases platelet aggregation. The study suggests that the majority of antirheumatic drugs mainly reduced cardiovascular risk through indirect effects (e.g., reducing inflammation).

Intravenous abatacept in Japanese patients with polyarticular-course juvenile idiopathic arthritis: results from a phase III open-label study

BACKGROUND

To investigate efficacy and safety of intravenous abatacept in Japanese patients with active polyarticular-course juvenile idiopathic arthritis (pJIA).

METHODS

In this phase III, open-label, multicenter, single-arm study, patients with pJIA aged 4-17 years who failed ≥1 biologic or methotrexate received weight-tiered (< 75 kg: 10 mg/kg; 75-100 kg: 750 mg; > 100 kg: 1000 mg) intravenous abatacept at Weeks 0, 2, 4, and every 4 weeks thereafter. The study comprised a short-term period (16 weeks) and ongoing long-term period. Primary endpoint: Week 16 JIA-American College of Rheumatology criteria 30 (JIA-ACR30) response rate. Secondary endpoints/outcomes included Week 16 JIA-ACR50/70/90 response and inactive disease rates, Childhood Health Assessment Questionnaire-Disability Index (CHAQ-DI), pharmacokinetics, safety, and immunogenicity. Proportions of patients achieving Juvenile Arthritis Disease Activity Score in 27 joints using C-reactive protein (JADAS27-CRP) remission (score < 1) and minimal disease activity (MDA; score < 3.8), were among exploratory endpoints.

RESULTS

All 20 patients who received study medication completed the short-term period. During the long-term period, two patients discontinued due to insufficient efficacy or patient decision. Median age and disease duration at baseline were 10.5 and 0.75 years, respectively. Week 16 JIA-ACR30 response rate (primary endpoint) was 90.0% (18/20). JIA-ACR50/70/90 response and inactive disease rates at Week 16 were 75.0% (15/20), 70.0% (14/20), 35.0% (7/20), and 25.0% (5/20), respectively. At Week 52, JIA-ACR30/50/70/90 response and inactive disease rates were observed by 88.9% (16/18), 88.9% (16/18), 83.3% (15/18), 66.7% (12/18) and 44.4% (8/18), respectively. CHAQ-DI improved after Week 12. JADAS27-CRP remission and MDA were achieved by 15.0% (3/20) and 45.0% (9/20) of patients at Week 16, and by 50.0% (9/18) and 78.0% (14/18) of patients at Week 52, respectively. The mean abatacept pre-dose serum concentration was above the target therapeutic exposure (10 μg/ml) from Week 8 through Week 16. All adverse events were of mild/moderate intensity, except for one case of severe gastroenteritis. No deaths, malignancies, or autoimmune disorders were observed. No antidrug antibodies were detected through Week 16; one patient had a positive immunogenic response during the cumulative period.

CONCLUSION

Intravenous abatacept was efficacious and well tolerated in Japanese patients with active pJIA.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01835470 . Date of registration: April 19, 2013.

Abatacept in combination with methotrexate in Japanese biologic-naive patients with active rheumatoid arthritis: a randomised placebo-controlled phase IV study

Objectives

To evaluate efficacy and safety of abatacept+methotrexate (MTX) in biologic-naive, anticitrullinated protein antibody (ACPA)-positive Japanese patients with active rheumatoid arthritis (RA) and early erosion versus placebo+MTX.

Methods

In this phase IV, multicentre, double-blind study (NCT01758198), patients were randomised (1:1) to receive intravenous abatacept (~10 mg/kg) or placebo, plus MTX (≥6 mg/week). Primary efficacy objectives were to compare American College of Rheumatology 20 (ACR20) response rates at week 16 and mean change from baseline in van der Heijde-modified total Sharp score (vdH-mTSS) at week 24 between abatacept+MTX and placebo+MTX groups.

Results

Overall, 203 and 202 patients received abatacept+MTX and placebo+MTX, respectively. At week 16, ACR20 response rates were higher in the abatacept (75.4%) versus placebo group (27.7%; p<0.001). Mean change from baseline in vdH-mTSS at week 24 was 0.84 in the abatacept and 1.26 in the placebo group (p=0.017). Radiographic non-progression rates (change in vdH-mTSS≤smallest detectable change (1.9)) were 88.1% and 75.4% in abatacept and placebo groups, respectively. Adjusted mean change from baseline in Disease Activity Score 28 (C-reactive protein) (DAS28 (CRP)) at week 16 demonstrated a numerically greater reduction in the abatacept versus placebo group. Proportions of patients with DAS28 (CRP), Simplified Disease Activity Index and Clinical Disease Activity Index remission up to week 52 were higher in the abatacept versus placebo group. The abatacept safety profile was consistent with previous observations.

Conclusions

Compared with MTX alone, abatacept+MTX improved clinical symptoms and inhibited structural damage progression in ACPA-positive, Japanese patients with RA, early erosion and inadequate response to MTX.

Population Pharmacokinetics and Exposure-Response Relationship of Intravenous and Subcutaneous Abatacept in Patients With Rheumatoid Arthritis

Abatacept population pharmacokinetics (PK) and exposure-response (E-R) models for selective efficacy end points were developed using phase 2 and 3 study data in patients with rheumatoid arthritis treated with abatacept (intravenous [IV] or subcutaneous [SC]), followed by simulations. Two efficacy end points were assessed in the E-R analyses: Disease Activity Score in 28 joints (DAS28) and American College of Rheumatology response criteria for 20/50/70% improvement (ACR20/50/70). The analyses were performed with data from 11 clinical studies for the population PK analysis and from 3 clinical studies for the E-R analyses (DAS28 and ACR20/50/70). The PK of abatacept were time invariant and can be described by a linear 2-compartment model with first-order elimination and with zero-order IV infusion or first-order absorption for SC abatacept. Baseline body weight was the only clinically meaningful covariate; that is, abatacept clearance and volume of central compartment increased with increasing baseline body weight. Steady-state trough concentration (C_minss ) of abatacept was identified as the best exposure predictor of DAS28 response compared with other exposure measures. In addition, the E-R relationship was the same for IV and SC abatacept. Similar results were confirmed in the ACR20/50/70 E-R analyses. Efficacy responses increased with increasing C_minss and a near-maximal response was associated with C_minss ≥10 μg/mL. The model-based analyses confirmed that the weight-tiered ∼10 mg/kg IV and fixed 125 mg SC abatacept dosing regimens are comparable and achieved plateau responses, by delivering C_minss ≥10 μg/mL in RA patients across all body weights.

Subcutaneous Abatacept in Patients With Polyarticular-Course Juvenile Idiopathic Arthritis: Results From a Phase III Open-Label Study

Objective

To investigate the pharmacokinetics, effectiveness, and safety of subcutaneous (SC) abatacept treatment over 24 months in patients with polyarticular‐course juvenile idiopathic arthritis (JIA).

Methods

In this phase III, open‐label, international, multicenter, single‐arm study, patients with polyarticular JIA (cohort 1, ages 6–17 years and cohort 2, ages 2–5 years) in whom treatment with ≥1 disease‐modifying antirheumatic drug was unsuccessful received weight‐tiered SC abatacept weekly: 10 to <25 kg (50 mg), 25 to <50 kg (87.5 mg), ≥50 kg (125 mg). Patients who had met the JIA–American College of Rheumatology 30% improvement criteria (achieved a JIA‐ACR 30 response) at month 4 were given the option to continue SC abatacept to month 24. The primary end point was the abatacept steady‐state serum trough concentration (C_minss) in cohort 1 at month 4. Other outcome measures included JIA‐ACR 30, 50, 70, 90, 100, and inactive disease status, the median Juvenile Arthritis Disease Activity Score in 71 joints using the C‐reactive protein level (JADAS‐71–CRP) over time, safety, and immunogenicity.

Results

The median abatacept C_minss at month 4 (primary end point) and at month 24 was above the target therapeutic exposure (10 μg/ml) in both cohorts. The percentage of patients who had achieved JIA‐ACR 30, 50, 70, 90, or 100 responses or had inactive disease responses at month 4 (intent‐to‐treat population) was 83.2%, 72.8%, 52.6%, 28.3%, 14.5%, and 30.1%, respectively, in cohort 1 (n = 173) and 89.1%, 84.8%, 73.9%, 58.7%, 41.3%, and 50.0%, respectively, in cohort 2 (n = 46); the responses were maintained to month 24. The median (interquartile range) JADAS‐71–CRP improved from baseline to month 4: cohort 1, from 21.0 (13.5, 30.3) to 4.6 (2.1, 9.4); cohort 2, from 18.1 (14.0, 23.1) to 2.1 (0.3, 4.4). Improvements were sustained to month 24, at which time 27 of 173 patients (cohort 1) and 11 of 22 patients (cohort 2) had achieved JADAS‐71–CRP remission. No unexpected adverse events were reported; 4 of 172 patients (2.3%) in cohort 1 and 4 of 46 (8.7%) in cohort 2 developed anti‐abatacept antibodies, with no clinical effects.

Conclusion

Weight‐stratified SC abatacept yielded target therapeutic exposures across age and weight groups, was well tolerated, and improved polyarticular JIA symptoms over 24 months.

Body mass index and clinical response to intravenous or subcutaneous abatacept in patients with rheumatoid arthritis

This post hoc analysis of ACQUIRE (NCT00559585) explored the effect of baseline body mass index (BMI) on the pharmacokinetics of and clinical response to subcutaneous (SC) or intravenous (IV) abatacept in patients with rheumatoid arthritis (RA). ACQUIRE was a phase 3b, 6-month, double-blind, double-dummy study in which patients with RA were randomized (1:1) to SC (fixed - dose; 125 mg/week) or IV (weight-tiered; ~ 10 mg/kg/month) abatacept plus methotrexate. In this analysis, minimum abatacept plasma concentration (Cmin) was measured at 3 and 6 months, and clinical remission over 6 months was assessed by Disease Activity Score 28 (C-reactive protein; DAS28 [CRP], < 2.6), Simplified Disease Activity Index (SDAI, ≤ 3.3), and Clinical Disease Activity Index (CDAI, ≤ 2.8). Data were stratified by baseline BMI (underweight/normal, < 25 kg/m2; overweight, 25 to < 30 kg/m2; obese, ≥ 30 kg/m2) and administration route. Of the 1456/1457 patients for whom baseline BMIs were available, 526 (36%; SC 265, IV 261) patients were underweight/normal, 497 (34%; SC 249, IV 248) were overweight, and 433 (30%; SC 221, IV 212) were obese. Median Cmin abatacept concentration was ≥ 10 μg/mL (efficacy threshold) at 3 and 6 months in > 90% of patients across BMI groups with both administration routes. DAS28 (CRP), SDAI, and CDAI remission rates at 6 months were similar across BMI groups and 95% confidence intervals overlapped at all time points in both separate and pooled SC/IV analyses. Therapeutic concentrations of abatacept and clinical remission rates using stringent criteria were similar across patient BMIs and administration routes.

Long-term safety and efficacy of treatment with subcutaneous abatacept in Japanese patients with rheumatoid arthritis who are methotrexate inadequate responders

OBJECTIVE

To assess the long-term safety, immunogenicity, and efficacy of subcutaneous (SC) abatacept in combination with methotrexate (MTX) in Japanese patients with rheumatoid arthritis who were MTX inadequate responders, in a long-term extension (LTE) to a double-dummy, double-blind study (NCT01001832).

METHODS

Patients, who had previously received SC or intravenous (IV) abatacept with MTX (6-8 mg/week) for 24 weeks, received SC abatacept (125 mg/week) with MTX for an additional 52 weeks. Safety, immunogenicity, and efficacy were assessed.

RESULTS

The LTE included 112 patients. SC abatacept was generally well tolerated in the LTE, with no new safety signals. American College of Rheumatology 20, 50, and 70 response rates, disease activity score 28 (C-reactive protein) remission rates (< 2.6), and Health Assessment Questionnaire-Disability Index response rates (≥ 0.3 improvement from baseline) achieved at the end of the double-blind period were maintained over the LTE and were comparable in patients who received SC or IV abatacept in the double-blind period. Seropositivity for immunogenicity occurred in 4 (3.6%) patients. Self-injection of SC abatacept was well controlled and not associated with additional safety events.

CONCLUSIONS

SC abatacept had acceptable safety and was well tolerated and effective over the LTE (76 weeks in total), with low rates of immunogenicity in Japanese patients.

Methotrexate monotherapy and methotrexate combination therapy with traditional and biologic disease modifying anti-rheumatic drugs for rheumatoid arthritis: A network meta-analysis

BACKGROUND

Methotrexate is considered the preferred disease-modifying anti-rheumatic drug (DMARD) for the treatment of rheumatoid arthritis, but controversy exists on the additional benefits and harms of combining methotrexate with other DMARDs.

OBJECTIVES

To compare methotrexate and methotrexate-based DMARD combinations for rheumatoid arthritis in patients naïve to or with an inadequate response (IR) to methotrexate.

METHODS

We systematically identified all randomised controlled trials with methotrexate monotherapy or in combination with any currently used conventional synthetic DMARD , biologic DMARDs, or tofacitinib. Three major outcomes (ACR50 response, radiographic progression and withdrawals due to adverse events) and multiple minor outcomes were evaluated. Treatment effects were summarized using Bayesian random-effects network meta-analyses, separately for methotrexate-naïve and methotrexate-IR trials. Heterogeneity was explored through meta-regression and subgroup analyses. The risk of bias of each trial was assessed using the Cochrane risk of bias tool, and trials at high risk of bias were excluded from the main analysis. The quality of evidence was evaluated using the GRADE approach. A comparison between two treatments was considered statistically significant if its credible interval excluded the null effect, indicating >97.5% probability that one treatment was superior.

MAIN RESULTS

158 trials with over 37,000 patients were included. Methotrexate-naïve: Several treatment combinations with methotrexate were statistically superior to oral methotrexate for ACR50 response: methotrexate + sulfasalazine + hydroxychloroquine ("triple therapy"), methotrexate + several biologics (abatacept, adalimumab, etanercept, infliximab, rituximab, tocilizumab), and tofacitinib. The estimated probability of ACR50 response was similar between these treatments (range 56-67%, moderate to high quality evidence), compared with 41% for methotrexate. Methotrexate combined with adalimumab, etanercept, certolizumab, or infliximab was statistically superior to oral methotrexate for inhibiting radiographic progression (moderate to high quality evidence) but the estimated mean change over one year with all treatments was less than the minimal clinically important difference of five units on the Sharp-van der Heijde scale. Methotrexate + azathioprine had statistically more withdrawals due to adverse events than oral methotrexate, and triple therapy had statistically fewer withdrawals due to adverse events than methotrexate + infliximab (rate ratio 0.26, 95% credible interval: 0.06 to 0.91). Methotrexate-inadequate response: In patients with an inadequate response to methotrexate, several treatments were statistically significantly superior to oral methotrexate for ACR50 response: triple therapy (moderate quality evidence), methotrexate + hydroxychloroquine (low quality evidence), methotrexate + leflunomide (moderate quality evidence), methotrexate + intramuscular gold (very low quality evidence), methotrexate + most biologics (moderate to high quality evidence), and methotrexate + tofacitinib (high quality evidence). There was a 61% probability of an ACR50 response with triple therapy, compared to a range of 27% to 64% for the combinations of methotrexate + biologic DMARDs that were statistically significantly superior to oral methotrexate. No treatment was statistically significantly superior to oral methotrexate for inhibiting radiographic progression. Methotrexate + cyclosporine and methotrexate + tocilizumab (8 mg/kg) had a statistically higher rate of withdrawals due to adverse events than oral methotrexate and methotrexate + abatacept had a statistically lower rate of withdrawals due to adverse events than several treatments.

AUTHORS' CONCLUSIONS

We found moderate to high quality evidence that combination therapy with methotrexate + sulfasalazine+ hydroxychloroquine (triple therapy) or methotrexate + most biologic DMARDs or tofacitinib were similarly effective in controlling disease activity and generally well tolerated in methotrexate-naïve patients or after an inadequate response to methotrexate. Methotrexate + some biologic DMARDs were superior to methotrexate in preventing joint damage in methotrexate-naïve patients, but the magnitude of these effects was small over one year.