Etanercept response in patients with rheumatoid arthritis after secondary loss of efficacy of infliximab

Phase III, multicentre, double-blind, randomised, parallel-group study to evaluate the similarities between LBEC0101 and etanercept reference product in terms of efficacy and safety in patients with active rheumatoid arthritis inadequately responding to methotrexate

OBJECTIVE

To evaluate the similarities between LBEC0101 (etanercept biosimilar) and the etanercept reference product (ETN-RP) in terms of efficacy and safety, including immunogenicity, in patients with active rheumatoid arthritis despite methotrexate treatment.

METHODS

This phase III, multicentre, randomised, double-blind, parallel-group, 54-week study was conducted in Japan and Korea. The primary efficacy endpoint was the change from baseline in the disease activity score in 28 joints based on erythrocyte sedimentation rate (DAS28-ESR) at week 24. American College of Rheumatology 20% (ACR20) response rate, adverse events (AEs), pharmacokinetics and development of antidrug antibodies (ADAs) were also evaluated.

RESULTS

In total, 374 patients were randomised to LBEC0101 (n=187) or ETN-RP (n=187). The least squares mean changes from baseline in DAS28-ESR at week 24 in the per-protocol set were -3.01 (95% CI -3.198 to -2.820) in the LBEC0101 group and -2.86 (95% CI -3.051 to -2.667) in the ETN-RP group. The estimated between-group difference was -0.15 and its 95% CI was -0.377 to 0.078, which was within the prespecified equivalence margin of -0.6 to 0.6. ACR20 response rates at week 24 were similar between the groups (LBEC0101 93.3% vs ETN-RP 86.7%). The incidence of AEs up to week 54 was comparable between the groups (LBEC0101 92.0% vs ETN-RP 92.5%), although fewer patients in the LBEC0101 group (1.6%) than the ETN-RP group (9.6%) developed ADAs.

CONCLUSION

The clinical efficacy of LBEC0101 was equivalent to that of ETN-RP. LBEC0101 was well tolerated and had a comparable safety profile to ETN-RP.

TRIAL REGISTRATION NUMBER

NCT02357069.

Which subgroup of rheumatoid arthritis patients benefits from switching to tocilizumab versus etanercept after previous infliximab failure? A retrospective study

A retrospective study of 39 rheumatoid arthritis (RA) patients with an inadequate response to infliximab was conducted. The responses of subjects switching from infliximab to tocilizumab (n = 23) were compared to those of subjects switching to etanercept (n = 16). Disease activity was assessed by the Disease Activity Score 28-CRP ([C-reactive protein] DAS28-CRP), the Simplified Disease Activity Index (SDAI), and the Clinical Disease Activity Index (CDAI). Twenty-two patients completed 48 weeks of tocilizumab treatment, and 15 patients completed 48 weeks of etanercept treatment. In both treatment groups, 1 patient each discontinued treatment because of lack of efficacy. No serious adverse events occurred during the study, and no patients in either group withdrew due to adverse events. At week 48, there was a significant reduction from baseline in DAS28-CRP, SDAI, and CDAI values after switching to either tocilizumab or etanercept, and there was no significant difference in efficacy, as measured by the DAS28-CRP, SDAI, and CDAI, between the two treatment groups (p = 0.12, 0.76, and 0.86, respectively). These results suggest that safety and tolerability were similar for both treatments. A switch from infliximab to either tocilizumab or etanercept in patients with RA who have not responded to infliximab is a feasible, well-tolerated treatment option.

Primary lack of efficacy of infliximab therapy for rheumatoid arthritis: pharmacokinetic characterization and assessment of switching to tocilizumab

To characterize primary failure to infliximab and determine the efficacy of switching to tocilizumab in patients with rheumatoid arthritis (RA), we examined 24 RA patients who had started on infliximab therapy (3 mg/kg) as their first biological agent. Nine of the 24 patients were found to be primary nonresponders, defined as patients who had never achieved a 20% clinical improvement according to the American College of Rheumatology criteria (ACR20) during induction therapy. The remaining 15 patients had achieved an ACR20 response to infliximab, without any relapses, for at least the first 14 weeks. A higher baseline health assessment questionnaire score was markedly associated with primary unresponsiveness to infliximab (p = 0.0005). Six of the 9 primary nonresponders showed rapid clearance of infliximab: their trough concentrations of infliximab were under 1 μg/ml. The other 3 were classified as exhibiting the residual type of unresponsiveness, which was defined as unresponsiveness in patients who maintained serum infliximab levels above 1 μg/ml. Human antichimeric antibody was not detected in the rapid-clearance nonresponders. Dose escalation (5 mg/kg) was insufficiently effective. Primary nonresponders to infliximab were started on tocilizumab therapy (8 mg/kg, every 4 weeks), and their responses were assessed after 24 weeks of this second attempt at therapy. All the nonresponders, except for a single rapid-clearance patient, had achieved an ACR20 clinical improvement at the time of assessment. In conclusion, primary nonresponders to infliximab can be classified into rapid-clearance and residual types, based on their trough concentrations of infliximab, but both types of nonresponders seem to benefit from an early decision to discontinue infliximab therapy and switch to tocilizumab.