Abatacept May Increase Chance of Achieving ACR70 Response Among Patients With RA

Compared with tocilizumab (TCZ), abatacept (ABA) may increase the chance of achieving at least a 70% improvement in the number of painful and swollen joints among patients with rheumatoid arthritis (RA), according to study results published in Advances in Rheumatology.

Investigators compared the efficacy of biologic disease-modifying antirheumatic drugs (bDMARDs) for treatment of patients with rheumatoid arthritis (RA) nonresponsive to methotrexate (MTX) treatment or tumor necrosis factor (TNF) inhibitor agents.

The investigators conducted a systematic review and meta-analysis of phase 2 to 4 randomized controlled trials (RCTs) that included individuals with RA refractory to MTX or TNF inhibitor agents, and assessed the efficacy of treatment with rituximab (RTX), ABA, or TCZ for at least 24 weeks, compared with a control group

Achievement of at least 70% improvement in the number of painful and swollen joints and improvement in 3 out of 5 American College of Rheumatology (ACR) parameters (C-reactive protein or erythrocyte sedimentation rate, patient’s assessment of pain, Health Assessment Questionnaire [HAQ] score, patient’s global assessment of the disease, and physician’s global assessment of the disease) was the primary endpoint (defined as an ACR70 response).

A total of 19 RCTs (N=7835; mean study follow-up, 1.2 years) were included in meta-analysis. All studies had low risk of bias and no significant publication bias or small-study bias was present.

The investigators found a critical imbalance among the bDMARDs in terms of study duration, HAQ score, and frequency of TNF inhibitor treatment. The high heterogeneity was attenuated and multivariate meta-regression was adjusted to these 3 factors in order to determine the relative risk (RR) for an ACR70 response.

According to this model, compared with ABA, RTX did not modify the chance of achieving an ACR70 response (RR, 1.773; 95% CI, 0.113-10.21; P =.765).

Compared with TCZ, ABA was associated with achieving an ACR70 response (RR, 2.217; 95% CI, 1.554-3.161; P <.001). If similar conditions were present among RCTs, the investigators estimate the chance of achieving an ACR70 response with ABA could be increased by 2.2-fold compared with TCZ.

At 6 months, hazard ratios (HRs) for achieving an ACR70 response showed no difference between the bDMARD therapies.

Among studies including ABA therapy, 25.6% of patients in the intervention arm and 19.8% in the control arm achieved an ACR70 response at 6 months (HR, 1.35; 95% CI, 1.17-1.55; P =.013; I²=41%).

Among studies including RTX therapy, 23.5% of patients in the intervention arm and 12.0% in the control arm achieved an ACR70 response at 6 months (HR, 2.43; 95% CI, 1.99-2.96; P <.001; I²=64%).

Among studies including TCZ therapy, 18.5% of patients in the intervention arm and 11.0% in the control arm achieved an ACR70 response at 6 months (HR, 1.53; 95% CI, 1.24-1.89; P =.002; I²=76%).

This analysis was limited by the high degree of heterogeneity among included studies and systematic data collection bias.

“With the present results, it is advisable to evaluate the introduction ABA or RTX

before TCZ in refractory RA. However, novel head to-head clinical trials are still needed to confirm these findings,” the study authors concluded.

Disclosure: One or more study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.