Belimumab 10 years later: how drug positioning has changed.

We analysed the change in the positioning of belimumab (BLM) in systemic lupus erythematosus (SLE) treatment in the first decade of real-life use, by providing data about patients treated by this biological drug in the Sapienza Lupus Cohort. We evaluated SLE patients treated by BLM according to the current clinical practice. Data of each patient were collected, focusing on previous and concomitant treatments. Finally, the drug retention rate was assessed. Since August 2013, 138 SLE patients started BLM (M/F 7/131; median age 49 years, IQR 13.25; median disease duration 214 months, IQR 180). To evaluate the change in BLM positioning, we divided patients according to the date of starting treatment as below: patients treated from 2013 to 2018 (period 1) and those treated since 2019 to date (period 2). Indeed, the median number of previous immunosuppressant drugs was significantly higher in patients treated in period 1 [3 (IQR 1.25) versus 1 (IQR 1.75), p = 0.0002]. Furthermore, 15.9% of patients treated in period 2 were not previously treated by immunosuppressant drugs, compared with 5.2% in period 1 (p = 0.01). Finally, the 24-month drug survival was significantly higher in patients previously treated with ≤ 1 immunosuppressant drug in comparison with those treated with ≥ 2 drugs (69.1% versus 43.4%, p = 0.0097, HR 0.49; 95% CI 0.27-0.88). Our data clearly described the progressive anticipation of BLM prescription in the first 10 years of clinical practice, underlining as choosing earlier biological agents could positively influence the drug retention rate.