A new study has determined modifiable and nonmodifiable factors that can help identify patients with axial spondyloarthritis who are both likely and unlikely to respond to anti–tumor necrosis factor (TNF)–alpha therapy.
“[This study] emphasizes that examination of predictors of nonresponse to pharmacologic therapy in inflammatory arthritis must consider the importance of socioeconomic factors,” wrote Gary J. Macfarlane, MBChB, PhD, of the University of Aberdeen (Scotland) and coauthors. The study was published in Rheumatology.
To identify common factors related to anti–TNF-alpha therapy response, the researchers launched a prospective cohort study of 335 patients with axial spondyloarthritis from the British Society for Rheumatology Biologics Register in Axial Spondyloarthritis (BSRBR-AS) who were naive to biologic therapy. Responses to therapy were assessed through various means, including meeting Assessment of Spondyloarthritis International Society (ASAS) improvement criteria, exhibiting clinically important improvement (1.1 points or more) in Ankylosing Spondylitis Disease Activity Score (ASDAS), or going from a high or very high ASDAS disease state (score of 2.1 or higher) to a moderate or inactive state (score less than 2.1).
All patients also filled out questionnaires at each follow-up on socioeconomic factors, lifestyle factors, and quality of life. Of the 335 participants, 69% were male. They had a median age of 47 years, and about half were employed full time.
At first follow-up – which occurred at a median of 14 weeks – 175 participants (52%) met ASAS20 response criteria and 111 (33%) met ASAS40 response criteria. Of the 261 participants eligible for ASDAS evaluation, 122 (47%) met the criteria for a clinically important ASDAS reduction. Of the 249 participants who had a high or very high disease state at baseline, 87 (35%) were classified as having moderate or inactive disease at follow-up.
Factors that predicted a lack of response across measures included adverse socioeconomic factors, fewer years of education, and not working full time. Clinical and patient-reported factors also associated with a lack of response included comorbidities and poor mental health. The ASDAS models proved best at predicting those unlikely to meet response criteria, with a negative predictive value of 77%.
The study was supported by the British Society for Rheumatology, which receives funding for the BSRBR-AS from Pfizer, AbbVie, and UCB. The authors reported having no conflicts of interest.
SOURCE: Macfarlane GJ et al. Rheumatology. 2020 Jan 28. doi: 10.1093/rheumatology/kez657.