Patients with rheumatoid arthritis (RA) who developed antibodies against adalimumab are not at increased risk of a thromboembolic event when compared to patients without these antibodies. These are the results from a study presented during the recent American College of Rheumatology Annual Meeting in San Francisco.
Rheumatoid arthritis (RA), the most common type of autoimmune arthritis, is triggered by a faulty immune system and affects the wrist and small joints of the hand, including the knuckles and the middle joints of the fingers. Treatments have improved greatly and help many of those affected. For most people with RA, early treatment can control joint pain and swelling, and lessen joint damage. Adalimumab (trade name Humira, AbbVie), is an anti-TNF drug targeting the TNF protein which is overproduced in the body of RA patients (and other inflammatory diseases), causing the inflammation and damage.
In their study, researchers performed a post-hoc analysis in a cohort of 3,995 patients with RA (identified from the Medical Dictionary for Regulatory Activities system organ class) who had received treatment with adalimumab, 367 of whom tested positive for adalimumab antibodies, representing 276.6 patient-years of exposure (a measurement of the length of exposure to treatment). Patients who tested negative for antibodies to adalimumab represented 2,255.7 patient-years. The analysis included such variables as cardiovascular accident, transient ischemic attack, myocardial infarction, and venous events. Venous events included deep vein thrombosis with or without pulmonary embolism, superficial vein thrombosis, and thrombosis.
The results revealed that 0.3% of patients with antibodies to adalimumab reported thromboembolic, treatment-emergent adverse events compared to 0.8% patients without these antibodies. Also, patients with antibodies to adalimumab had an incidence rate of 0.4 events per 100 patient-years versus 1.4 events per 100 patient-years in those without these antibodies. Importantly, the incidence of serious adverse events in patients with or without antibodies to adalimumab was of 0.4 and o.7 events per 100 patient-years, respectively.