Tocilizumab a valuable therapeutic option in RA patients with poor response to bDMARDs
Tocilizumab (TCZ) monotherapy or combined with conventional synthetic (cs) disease-modifying antirheumatic drugs (DMARDs) represents a valuable option in the treatment of rheumatoid arthritis (RA) patients with inadequate response to biologic (b)DMARDS, according to a recent study.
Specifically, treatment with TCZ alone or in combination with csDMARDs has demonstrated comparable efficacy but longer retention relative to tumour necrosis factor inhibitors (TNFIs).
The study included adult RA patients who had previously received at least one bDMARD and subsequently underwent treatment courses with TCZ monotherapy (n=771), TCZ combo (n=1,773), TNFI monotherapy (n=1,404) or TNFI combo (n=4,660). Generally, TCZ patients were slightly older, had longer disease duration and received more previous bDMARDs.
Median retention was higher in treatment groups containing TCZ (2.31 years with monotherapy; 1.39 years with combo) than in those containing TNFI (1.37 years with combo; 1.31 years with mono). [Ann Rheum Dis 2018;doi:10.1136/ annrheumdis-2017-212845]
In multivariable Cox models, the risk of treatment discontinuation was significantly lower with TCZ mono and combo vs TNFI combo (hazard ratios [HRs], 0.78 and 0.70, respectively; p<0.001 for both) or TNFI mono (HR, 0.65 for both; p<0.001). There was no marked difference observed between TCZ mono and TCZ combo (HR], 0.96; p=0.53).
Meaningful reductions in Clinical Disease Activity Index (CDAI) score occurred over time, but without significant between-group differences. The average adjusted CDAI change at 1 year was −3.54 with TNFi mono, −3.34 with TNFi combo, −3.68 with TCZ combo and −3.58 with TCZ mono.
Finally, CDAI remission and low disease activity rates were comparable across the four treatment groups.
Although drug retention was higher in TCZ-treated patients than in TNFI-treated ones, the effectiveness of the two treatments remained similar. According to the investigators, such discrepancy indicates that either CDAI does not allow a comprehensive assessment of drug efficacy or that retention probably captures something that is not evaluated by CDAI, such as patient or physician preference.
“It is also possible that TCZ treatment, being used after several bDMARDs failure, is maintained even if not achieving the ideal target due to the lack of treatment alternatives,” they added.
The investigators concluded that it is reasonable to use TCZ monotherapy or in combination with csDMARDs for treating patients with inadequate response to at least one bDMARD.
“Consistent with the findings, the current European League Against Rheumatism recommendations for the management of RA mention that interleukin-6 inhibitors [such as TCZ] … may have some advantage over other bDMARDs, if patients cannot use csDMARD.” [Ann Rheum Dis 2017;76:960-977]
The study had several limitations. Among those cited by the investigators were the observational nature of the data and inclusion of only patients who previously used at least one bDMARD.