Tocilizumab, rituximab outperform other biologicals for RA
medwireNews: Findings from two registry-based studies suggest that tocilizumab and rituximab may be associated with better treatment outcomes than abatacept and tumour necrosis factor (TNF) inhibitors among patients with rheumatoid arthritis (RA).
In the first study, an analysis of 3162 patients from three French registries who were treated with non-TNF inhibitor biologicals between 2005 and 2013, the researchers found that patients treated with tocilizumab or rituximab were more likely to remain on treatment without failure at the 2-year follow-up than those given abatacept, at rates of 63.4% and 68.6% versus 39.3%, respectively, after inverse probability weighting.
Jacques-Eric Gottenberg (Strasbourg University Hospital, France) and co-investigators report in The BMJ that the average duration of treatment without failure – as estimated by restricted mean survival times – was 19.1 months in the tocilizumab group, 19.8 months in the rituximab group and 15.6 months for patients treated with abatacept.
Treatment failure was defined as all-cause mortality, discontinuation, initiation of a new agent or an increase in corticosteroid dose of more than 10 mg/day from baseline at two successive visits, and propensity scoring was used to account for differences between the groups.
The researchers say that serious adverse event profiles did not differ among patients treated with the three biologicals. Patients in the tocilizumab, rituximab and abatacept groups were treated for an average of 22.3 months, 22.1 months and 21.8 months, respectively, without experiencing serious adverse events.
“Therefore, the observed higher drug retention rate of rituximab and tocilizumab compared with abatacept is related to greater effectiveness rather than a better safety profile”, they write.
Gottenberg and team note that the patients in their study had longstanding disease (median duration = 10–12 years in the weighted cohort) and a prior inadequate response to TNF inhibitors, and thus their findings may not be applicable to “biologic agent naïve patients with shorter disease duration.”
The second study investigated treatment response among patients from the Swedish Rheumatology Register who initiated treatment with tocilizumab, rituximab, abatacept or a TNF inhibitor between 2010 and 2016, either as their first biological DMARD or after switching from a TNF inhibitor as their first biological.
As reported in Rheumatology, the ARTIS Study Group found that patients who started non-TNF inhibitors as their first biological were more likely to remain on and respond to treatment than their counterparts commencing TNF inhibitors.
Specifically, 76.2% of 317 patients starting tocilizumab treatment as their first biological, 88.3% of 938 initiating rituximab and 75.9% of 376 given abatacept remained on treatment after 1 year, compared with 69.4% of 7702 individuals initiating TNF inhibitors. The proportion of patients who achieved a EULAR good response was 50.9%, 28.6% and 31.9% compared with 24.9%, respectively.
And for patients who switched from a first-line TNF inhibitor, the study authors say that the 457 patients switching to tocilizumab and the 528 switching to rituximab, but not the 408 who switched to abatacept, had better treatment outcomes than the 2548 patients switching to another TNF inhibitor. For example, EULAR good response rates at 1 year were 34.1%, 24.8%, 13.1% and 11.6%, respectively, and a corresponding 31.3%, 20.4%, 9.7% and 14.6% achieved a disease activity score at 28 joints of less than 2.6 points.
These findings “are in line with a superior effectiveness of non-TNF [inhibitor biological] DMARDs, in particular tocilizumab and rituximab, compared with TNF [inhibitors]”, conclude Thomas Frisell (Karolinska University Hospital, Stockholm, Sweden) and colleagues.
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