Abstract
To date, belimumab is the only biological drug approved for the treatment of patients with active refractory SLE. We compared and critically analyzed the results of 11 observational clinical-practice-based studies, conducted in SLE referral centers. Despite the differences in endpoints and follow-up duration, all studies remarked that belimumab provides additional benefits when used as an add-on to existing treatment, allowing a higher rate of patients to reach remission and to taper or discontinue corticosteroids. In the OBSErve studies, 2-9.6% of patients discontinued corticosteroids and 72-88.4% achieved a ≥ 20% improvement by physician's judgment at 6 months. In Hui-Yuen's study, 51% of patients attained response by simplified SRI at month 6. In Sthoeger's study, 72.3% of patients discontinued corticosteroids and 69.4% achieved clinical remission by PGA after a median follow-up of 2.3 years. In the multicentric Italian study, 77 and 68.7% of patients reached SRI-4 response at months 6 and 12, respectively. In all the studies, disease activity indices decreased over time. Retention rates at 6, 9, and 12 months were 82-94.1, 61.2-83.3, and 56.7-79.2%, respectively. The main limitations of these studies include the lack of a control group, the short period of observation (6-24 months) and the lack of precise restrictions regarding concomitant medication management. This notwithstanding, these experiences provide a more realistic picture of real-life effectiveness of the drug compared with the randomized controlled clinical trials, where stringent inclusion/exclusion criteria and changes in background therapy could limit the inference of data to the routine clinical care.