Rheumatoid Arthritis Treatment Response Cannot be Predicted from Synovial Tissue Biopsy, Researchers Find
A new study published in the November 2023 issue of The Lancet Rheumatology has revealed disappointing results. According to the study’s principal investigator, Dr. Costantino Pitzalis from the Center for Experimental Medicine and Rheumatology at Queen Mary University of London, there is still no reliable way to predict how rheumatoid arthritis patients may respond to certain drugs.
The study, named the STRAP trials, combined data from two clinical studies conducted in the UK and Europe, involving 223 biologic-naïve adult patients. This is the largest study to date based on biopsies, targeting synovial tissue to inform research decisions for treating rheumatoid arthritis.
Dr. Annette H. van der Helm-van Mil, a professor of Rheumatology at Leiden University Medical Center in the Netherlands, commented on the study’s results in an editorial accompanying the publication. Most research on predicting treatment response has been based on clinical characteristics and blood biomarkers, but neither approach is reliable.
The results also indicate that a dichotomous classification of sparse versus abundant synovial B cells does not predict treatment response in patients treated with rituximab compared with etanercept or tocilizumab. The conclusions drawn from these results are similar to those found in a study conducted by the same researchers in 2021. However, the classification of scarce B cells by RNA sequencing did make a difference in the study from 2021.
The results of the studies highlight the importance of conducting advanced molecular analyses of synovial tissue and the need for a larger, more detailed study to develop predictive models for the treatment of rheumatoid arthritis.
Dr. Harris R. Perlman, chief of rheumatology at Northwestern University Feinberg School of Medicine, emphasized the importance of understanding tissue on a single-cell basis using gene expression to get an idea of what is happening in the tissue.
Further research incorporating multiple sources of patient information, from gene expression to clinical symptoms, is necessary to advance the field of precision treatment for rheumatoid arthritis. Precision medicine for rheumatoid arthritis is close, but understanding the details is crucial.
The STRAP and STRAP-EU trials were jointly funded by the UK Medical Research Council and Versus Arthritis, with study drugs donated by Pfizer and Roche. Many authors have financial relationships with pharmaceutical companies, while some have disclosed no relevant financial relationships.