Researchers Report Positive Early Data for SB2 in Treating IBD

A growing body of data on the use of Celltrion’s CT-P13 (Inflectra, Remsima) has underscored the biosimilarity of the product with the reference infliximab, Remicade, including in extrapolated indications such as inflammatory bowel disease (IBD). However, another approved biosimilar infliximab, SB2, which is available to patients in the United States and in the European Union under the brand names Renflexis and Flixabi, respectively, has been the subject of less research in treating IBD.

A recent letter, published in Alimentary Pharmacology and Therapeutics, reported on early findings from an ongoing, 18-month, multicenter, observational prospective study conducted among the cohort of the Sicilian Network for Inflammatory Bowel Disease. According to the authors of the letter, these are the first data on SB2 in treating IBD.

All patients with IBD who started SB2 from the introduction of the drug in Sicily in March 2018 to September 2019 are, or will be, eligible for inclusion of the study. The primary end point of the study is the assessment of safety in terms of the rate of serious adverse events (AEs). Secondary end points include efficacy, measured in terms of the proportion of patients achieving steroid-free clinical remission and response at 8 weeks and at the end of follow-up.

As of September 2018, 77 patients with IBD were enrolled in the study. Of these patients, 50.6% had Crohn disease and 49.4% had ulcerative colitis. In total, 66 patients were infliximab naïve, 8 switched from the reference product, and 3 switched from CT-P13. The total number of infusions of SB2 was 215, and the mean follow‐up was 2.2 (± 1.7) months.

Serious AEs occurred in 7 of the patients (9.1%), with an incidence rate of 49.3 per 100 person-years. Three infusion reactions, 3 arthritic flares and/or arthralgia, and 1 case of flu-like sickness were reported; 6 of the serious AEs led to discontinuation.

The efficacy of the biosimilar was assessed in the 35 patients who had completed at least 8 weeks of follow-up, and in total, 17 patients (48.6%) had achieved steroid-free remission at 8 weeks, while 8 patients (22.8%) had achieved a partial response. Ten patients (28.6%) had no response. Among responders, at 12, 16, and 20 weeks, efficacy rates were 96.6%, 89.1%, and 72.8%, respectively.

Further data from the study will be reported in the future. “Even if our preliminary results seem reassuring about effectiveness and safety of SB2,” write the letter’s authors, “they need to be confirmed at the end of the study, when more patients and a longer follow‐up will be available.”

Reference

Macaluso FS, Cappello M, Giuffrida E, et al. Letter: SPOSIB SB2—a Sicilian prospective observational study of IBD patients treated with infliximab biosimilar SB2. Aliment Pharmacol Ther. 2019;49(2):234-236. doi: 10.1111/apt.15071.