A new real-world study from China provides compelling evidence that the adalimumab biosimilar IBI303 delivers comparable clinical outcomes to Humira while offering significant cost advantages for patients with ankylosing spondylitis. The retrospective analysis, conducted at Shenzhen Luohu People's Hospital and published in Medicine (Baltimore), examined 106 patients treated between May 2020 and December 2023.
Superior Retention Rates with Lower Costs
The study revealed that IBI303 demonstrated higher retention rates compared to Humira at key time points. At 52 weeks, 63% of patients remained on IBI303 treatment versus 44% on Humira. Early retention at 24 weeks also favored the biosimilar, with 82% of IBI303 patients continuing treatment compared to 67% of Humira patients.
Cost analysis showed substantial savings with IBI303. Median treatment costs were significantly lower at 12 weeks ($762.20 vs $903.70; P = .042) and at 52 weeks ($2543.00 vs $2982.30; P = .004). These findings address a critical access barrier, as Humira's high cost of approximately $2,250 USD per month has limited patient access to this effective therapy in China.
Comparable Safety and Efficacy Profiles
Safety outcomes between the two treatments were nearly identical. Only 2 patients in each group experienced mild infusion-related reactions, with no statistically significant differences in adverse event incidences between groups (P > .05). Drug exposure every 4 weeks during the first 52 weeks was similar between groups: 55.0 weeks (95% CI 44.2–66.7) for Humira and 55.6 weeks (95% CI 43.3–69.6) for IBI303.
The retention rates at 12 weeks were 0.87 (95% CI 0.81–0.92) for Humira and 0.90 (95% CI 0.68–0.93) for IBI303, while at 52 weeks they were 0.44 (95% CI 0.34–0.52) and 0.63 (95% CI 0.57–0.69), respectively.
Clinical Context and Implications
Ankylosing spondylitis is a chronic inflammatory disease that causes axial arthritis and often results in inflammatory lower back pain early in the disease course. If left untreated, the inflammation can lead to severe impairment of spinal mobility due to structural changes and eventual spinal fusion. The condition affects an estimated 0.2% to 0.5% of the US population, with global occurrence ranging from 0.4 to 14 new cases per 100,000 people annually.
The study builds upon previous phase 3 trial data (NCT02893254) that established clinical equivalence between IBI303 and Humira. In that randomized, controlled, double-blind trial, approximately 75% of patients in the IBI303 group and 72% in the Humira group reached the primary outcome at 24 weeks, with similar safety and tolerability profiles.
Broader Healthcare Impact
The research provides valuable real-world evidence supporting biosimilar adoption beyond controlled clinical trial settings. The authors noted that their drug exposure results could provide data support for tapering of biological therapy, potentially offering additional cost savings through optimized dosing strategies.
"From a Chinese perspective, there is no difference in retention rate and safety between IBI303 and Humira in real-world use of patients with ankylosing spondylitis, but because IBI303 has a lower price, it will lighten patients' economic burden," the study authors concluded.
The findings have implications extending beyond China's healthcare system, as they demonstrate that biosimilars can serve as viable first-line treatment options rather than merely budget alternatives, potentially expanding access to effective adalimumab therapy while controlling healthcare costs.
