Fewer patients in the real-world vs clinical trials may achieve a satisfactory response to tumor necrosis factor inhibitor (TNFi) treatment in axial spondyloarthritis (axSpA), according to study results published in Annals of the Rheumatic Diseases.
To determine and compare treatment response to TNFis among patients in the real-world and clinical trials, the researchers included 816 participants starting TNFis who were recruited by the British Society for Rheumatology Biologics Register for Ankylosing Spondylitis (BSRBR-AS); patients continuing to receive conventional therapy were included in the nonbiologic cohort.
Researchers indicated a shorter symptom duration and more severe disease among patients starting TNFi treatment vs those continuing conventional therapy. Patients were also younger in the BSRBR-AS biologic vs the nonbiologic cohort (mean age, 44.3 vs 50.1 years). Data from 14 randomized trials were identified and analyzed to determine the differences between the 2 groups. Researchers noted several differences between the 2 groups, including 67% vs 71% of patients in the treatment vs control group, respectively, were men; in addition, patients starting TNFis were about 6 years older than trial participants.
Of the 816 participants in the BSRBR-AS cohort, 333 (41%) would have met the criteria for clinical trial participation; however, 52% of patients who would not have been eligible showed a positive treatment response as part of the BSRBR-AS treatment cohort. There were no major differences in disease activity between participants in both groups. Overall, treatment response was significantly lower than that reported by clinical trials.
Based on these findings, the researchers concluded that clinical trial participants were not representative of real-world patients who may benefit from TNFi treatment. They hypothesized that this was because patients who are selected for trials may be of a higher socioeconomic status, better educated, and have better health overall. These factors could account for clinical trial participants being more likely to have a positive treatment outcome vs the patient population they are meant to represent.
“The rheumatologist needs to consider that the [percentage] of patients who achieve a satisfactory treatment response to TNF inhibition will be lower than might be expected from clinical trials. This has implications for cost-effectiveness of therapy and perhaps, therefore, choice of agent,” the researchers noted.
Jones GT, Dean LE, Pathan E, Hollick RJ, Macfarlane GJ. Real-world evidence of TNF inhibition in axial spondyloarthritis: can we generalise the results from clinical trials? [published April 23, 2020]. Ann Rheum Dis. doi:10.1136/annrheumdis-2019-216841