Adalimumab, IBI303 biosimilar demonstrate comparable safety, efficacy in AS
IBI303, a biosimilar to adalimumab developed by Chinese biopharmaceutical company Innovent Biologics, is comparable in safety and efficacy to the originator drug among patients with ankylosing spondylitis, according to data published in The Lancet Rheumatology.
“China approved adalimumab for the treatment of rheumatoid arthritis in 2010 and ankylosing spondylitis in 2013,” Huji Xu, MD, of Shanghai Changzheng Hospital and the Second Military Medical University, in Shanghai, and colleague wrote. “However, the cost of the standard dose regimen exceeds ¥15,000 (around U.S. $2,250) per month, which is well beyond the affordability of most Chinese patients, considering the cost is not covered by health insurance in China. Thus, the development of biosimilars as an alternative strategy to the high cost of adalimumab will make treatment more widely available to patients.”
“IBI303 is highly similar to adalimumab in spatial structure; pharmacodynamic and toxicokinetic studies have shown similar results for both drugs,” they added. “The in vitro inhibitory effects of IBI303 on inflammation and angiogenesis have been shown in WEHI 164 cells.”
To determine the clinical equivalence of IBI303 to adalimumab (Humira, AbbVie) among patients with ankylosing spondylitis, Xu and colleagues conducted a phase 3, double-blind, parallel, randomized controlled trial across 20 centers in China. A total of 438 patients aged 18 to 65 years who fulfilled the 1984 Modified New York Criteria for ankylosing spondylitis, with two or more indicators of disease activity, and who demonstrated inadequate response to, or were intolerant of, treatment with NSAIDs for 4 or more weeks, were recruited.
Participants were randomly assigned into one of two treatment groups, with 220 patients receiving 40 mg of IBI303 and 218 treated with 40 mg of adalimumab. Both treatments were administered through subcutaneous injection every 2 weeks until week 22. The primary outcome was the proportion of participants who met the Assessment of Spondyloarthritis International Society response criteria for a 20% improvement (ASAS20) at week 24 following treatment.
The researchers established that equivalence would be achieved if the 95% confidence interval of the differences in responses between the groups was between –15% and 15%. Safety analyses were performed in all assigned participants treated with at least one drug dose.
According to the researchers, 75% of participants in the biosimilar group (95% CI, 68.7-80.6) and 72% of those who received the originator drug (95% CI, 66-78.3) achieved the primary outcome. The difference between the two treatment groups was 2.3% with a 95% CI of –5.9 to 10.6, meeting the researchers’ definition of equivalence.
Meanwhile, in the per-protocol population, 80% of 203 patients in the biosimilar group achieved the primary endpoint (95% CI, 74.1-85.5), compared with 80% of 188 patients who received adalimumab (95% CI, 73.3-85.3). The difference between the groups in this population was 0.6%, with a 95% CI of –7.4 to 8.6, also within the pre-specified parameters for equivalence.
Safety and tolerability profiles were similar between the both groups, with 79% of the full IBI303 population and 82% of the full adalimumab group, demonstrating treatment-emergent adverse events.
“Development of biosimilars like IBI303 provides a tremendous benefit to the large patient population in China with autoimmune and rheumatic diseases, whose medical needs are hindered by the high prices of originator drugs like adalimumab and infliximab (which cost approximately U.S. $9,000 to $16,500 per year),” Xu and colleagues wrote.
“In light of the giant gap between the medical need and affordability of drugs that treat conditions like ankylosing spondylitis, the National Medical Products Administration of China have issued technical guidelines for the regulation of biosimilars in 2015, a key step to foster and facilitate China’s domestic development of biosimilars,” they added. “We anticipate incoming approval for biosimilars like IBI303 in China, which will substantially improve patient access to treatments for autoimmune and rheumatic diseases.” – by Jason Laday
Disclosure: Xu reports funding for this study from Innovent Biologics. Other researchers report employment with Innovent Biologics.