E039 Association between ethnicity and initial response to TNF inhibitors in people with rheumatoid arthritis: Results from the British Society for Rheumatology Biologics Register for Rheumatoid Arthritis (BSRBR-RA)
Authors: Tsoi Man Fung , Andev Rajinder S , Kearsley-Fleet Lianne , Watson Kath , Dubey Shirish , Kumar Kanta , Moorthy Arumugam , Gupta Monica ,   BSRBR-RA, Adebajo Adewale O , Hyrich Kimme L 
Published: April 2023

Abstract

Background/Aims
Little is known about the association between ethnicity and response to TNF inhibitors (TNFi) in people with rheumatoid arthritis (RA). This study examines the association between self-reported ethnicity and DAS28 response after 6 months of treatment in patients starting their first TNFi using data from the British Society for Rheumatology Biologics Register for RA.

Methods
14133 RA patients with self-reported ethnicity starting their first TNFi were included. Due to a very low proportion of non-white patients, ethnicity was divided into white or non-white for analysis. Outcomes included the change in disease activity using DAS28, the proportion of patients who achieved DAS28 remission and EULAR response at month 6. Adjusted regression models appropriate to outcome were used to compare between the two groups. Multiple imputation was used to account for missing data.

Results
Of 14133 patients starting TNFi with recorded ethnicity, only 607 (4.3%) recorded themselves as non-white (389 Asian, 134 Black, 57 Mixed ethnicity and 27 other) (Table). At start of TNFi, non-white patients were younger (non-white vs. white: mean 51 vs. 57 years; p &lt; 0.001), with shorter disease duration (median 8 vs. 10 years; p &lt; 0.001), higher proportion of females (86% vs. 76%; p &lt; 0.001) and fewer current cigarette smokers (9% vs. 20%; p &lt; 0.001). Non-white patients had lesser improvement in DAS28 at month 6 (adjusted regression coefficient (95% confidence interval (95%CI)): 0.3 (0.04-0.5)). However, using the white patients as a reference, non-white patients were not associated with the achievement of DAS28 remission (adjusted odds ratio (95%CI): 0.7 (0.5-1.1)) or EULAR response (aOR (95%CI): 0.8 (0.7-1.0)) at month 6.

Conclusion
Recruitment to the BSRBR-RA of non-white patients was exceptionally low compared to expected population distribution - the reasons for this are not immediately evident. Among those recruited, there were no significant differences observed in initial treatment response although non-white patients were younger, more likely to be female, had shorter disease duration and less likely to be smokers. Further evaluation into ways to both increase representativeness in our national RA treatment register and influence of ethnic differences on longer term outcomes with biologic therapies is warranted.
Disclosure
M. Tsoi: None. R.S. Andev: Other; R.S.A. reports speaker fees from Novartis. L. Kearsley-Fleet: None. K. Watson: None. S. Dubey: Honoraria; S.D. reports honoraria from Boehringer Ingelheim. Other; S.D. reports speaker fees from Janssen. K. Kumar: None. A. Moorthy: Honoraria; A.M. reports honoraria from Eli-Lilly and UCB. Other; A.M. reports speaker fees from Novartis and Galapagos. M. Gupta: None. A.O. Adebajo: None. K.L. Hyrich: Honoraria; K.L.H. reports honoraria from Abbvie. Grants/research support; K.L.M reports grant income from Pfizer and BMS.