Comparative real-world retention rate and safety of biosimilar IBI303 versus Humira in ankylosing spondylitis: A retrospective study

Biosimilars play an important role in reducing the economic burden on patients, but the effectiveness of biosimilars in real-world is also being challenged. This study aims to evaluate Humira and IBI303 for ankylosing spondylitis (AS) by retention rate and safety through real-world data. We extracted patient information from the hospital information system of Shenzhen Luohu People's Hospital, the time range is from May 1, 2020, to December 31, 2023, and conducted a retrospective study. The primary study outcome was the adalimumab retention rate at week 52 and it was estimated through survival analysis. We analyzed the data of 106 patients with AS. Among them, the retention rates of 38 patients using Humira at 12 weeks and 52 weeks were 0.87 (95% confidence interval [CI]: 0.81-0.92) and 0.44 (95% CI: 0.34-0.52), and in the IBI303 group were 0.90 (95% CI: 0.68-0.93) and 0.63 (95% CI: 0.57-0.69), respectively. Drug exposure every 4 weeks of first 52 weeks were 55.0 (44.2-66.7) and 55.6 (43.3-69.6) in Humira and IBI303 group, respectively. The incidence of adverse reactions was no statistically significant difference between the Humira and IBI303 groups (P > .05). However, the Humira group had significantly higher median costs in the first year than the IBI303 group (P = .004). In conclusion, in Chinese AS patients, there is no difference in retention rate and safety between generic and brand-name adalimumab in real-world use, but IBI303 is the more cost-effective choice.