Abstract Background/Aims Adalimumab (ADA) is licensed and recommended by the BSR and NICE for patients with severe axial spondyloarthritis (axSpA) at a dose of 40mg alternate weeks. There is evidence from the gastroenterology literature showing enhanced efficacy with weekly dosing in Crohn’s disease. A proportion of axSpA patients treated with adalimumab demonstrate secondary non-response (SNR) which may be related to the development of drug antibodies or sub-therapeutic ADA levels. We have undertaken a service improvement project whereby patients with SNR to adalimumab who have sub-therapeutic ADA levels without adalimumab antibodies can now be escalated to weekly ADA dosing at our centre. Methods We approached consecutive patients with axSpA and axial PsA, who demonstrated SNR to adalimumab between March 1, 2023, and March 31, 2025. Patients with adalimumab antibodies and those with therapeutic ADA levels were excluded. The following data were recorded at baseline and 12 weeks post escalation; BASDAI, CRP and ADA levels. Results Twenty-five eligible patients were identified and offered weekly ADA (22 axSpA and 3 axial PsA). The mean age was 50.4 years and 52% were male. One patient declined and opted for JAK-I, two patients were lost to follow-up and one patient is awaiting a week 12 clinic review. For 88% (n = 22), ADA was their first advanced therapy, with three patients also treated with etanercept, golimumab and methotrexate. 19 out of 21 weekly ADA patients demonstrated improved efficacy; mean BASDAI reducing from 6.09 (SD 1.45) to 4.19 (SD 2.1) and mean CRP from 7.73 (SD 8.69) to 3.0 (SD 3.01) at week 12. Mean ADA levels increased to 7.21 (SD 6.39) from baseline 2.84 (SD 1.98). No new safety signals were identified. BASDAI data for individual patients are outlined in the attached figure. Conclusion These preliminary data suggest that there is a role for weekly ADA dosing in a cohort of axSpA and axial PsA patients demonstrating secondary non-response to standard ADA dosing and who have sub-therapeutic ADA levels. This approach has potential cost savings compared with switching to a different mode of action. This single centre pilot project has now been extended to include other UK centres. Disclosure W. Mushtaq: None. A. Onajole: None. H. Marrison: None. L. Hamilton: None. K. Gaffney: None.
Mushtaq et al. (2026) studied this question.