A retrospective review of the adverse effects of biological therapy and reasons for its discontinuation in a resource-limited setting.

Abstract

Biological disease-modifying antirheumatic drug therapies have become the gold standard of treatment for refractory rheumatic conditions in well-resourced countries. There is a significant risk of infection and reactivation of latent infections, in particular tuberculosis, with the use of biological therapies. Their safety and reasons for discontinuation in a resource-limited environment are still unclear. The primary objective was to describe the nature and frequency of adverse events as well as the main reason for discontinuation of biological treatment. We conducted a retrospective, descriptive folder review of all patients started on biological therapy for rheumatic conditions from November 2011 to December 2016. A total of 31 patients were included. The rheumatic diseases included in the study were ankylosing spondylitis (AS) (35%), rheumatoid arthritis (RA) (19%), systemic lupus erythematosus (16%), juvenile idiopathic arthritis (13%), vasculitides (10%) and psoriatic arthritis (7%). Adverse events occurred in 26 patients (84%). Serious adverse events occurred in 14 patients (45%) with recurrent uveitis being the most common, occurring in 5 patients (16%). One patient developed pulmonary tuberculosis (PTB). Discontinuation or switching of biological therapy occurred in 13 patients (42%), with the main reasons being serious adverse events in 7 patients (23%) and treatment failure in 6 (19%). The median (interquartile range (IQR)) Bath Ankylosing Spondylitis Disease Activity Index score improved from 6.4 (5 - 7.4) to 2.8 (0.9 - 5.0), a statistically significant difference of -3.5 (p=0.001) (95% confidence interval (CI) -5.3 - -1.7) over a median (IQR) of 20 (9 - 30) months in the AS group. The median (IQR) Clinical Disease Activity Index score improved from 39 (34.5 - 43) to 21 (18.7 - 25.5), a statistically significant difference of -17.4 (p=0.044) (95% CI -34.1 - -0.7) over a median (IQR) of 39 (21 - 50) months in the RA group. Recurrent uveitis occurred in almost half of the patients with AS and was also the main reason for discontinuation of biological therapy. We did not document an increased risk of PTB. Disease activity scores showed significant improvement. The study is limited by the small number of patients on biological therapy, a reflection of the impact of severe resource constraints.