The findings of a new study suggest it may be possible to determine long-term responses to anti-tumor necrosis factor (TNF) treatment in patients with rheumatoid arthritis (RA) before six months.
The study, published in Rheumatology, analysed data from the British Society for Rheumatology Biologics Register for RA (BSRBR-RA) for 14,436 patients with RA starting their first anti-TNF drug between 2001 and 2013. Six monthly DAS28-ESR scores were used to identify trajectories of disease activity. Data were included for six follow-ups after registration (approximately three years). Subgroup analysis examined changes in disease activity profiles over time.
The mean number of DAS28-ESR scores was 3.5/patient (standard deviation [SD], 2.1), with a mean of 184.9 days (SD, 69.9) between scores.
The DAS28-ESR nadir was achieved within 250 days of commencing anti-TNF, although apparent trajectory divergence emerged by the first six-month follow-up. Response could be seen before the six-month follow-up.
Most patients fit into the category of 'modest' (55.3%) or 'substantial' (32.4%) response trajectories. Of the remainder, 8.7 per cent and 3.6 per cent fitted into 'maximal' and 'minimal' response trajectory categories, respectively.
There was a significant (P<.01) increase in proportion achieving 'maximal' response between 2001-2008 and 2010-2013.
The authors concluded that different trajectories of response identified at six months are indicative of future outcomes with anti-TNF treatment in RA. However, they say, based on the findings of early divergence of trajectories, assessment of anti-TNF efficacy may be possible before the currently recommended six-month review, which would enable patients with suboptimal response to switch treatments earlier, improving outcomes and minimising cost of inefficacious treatments.
