Samsung Bioepis and Organon recently announced positive topline results from a Phase IV clinical trial of SB5, a biosimilar to the reference tumor necrosis factor (TNF) blocker Humira (adalimumab), in patients with moderate-to-severe chronic plaque psoriasis (PsO). The study met its primary endpoint of comparable pharmacokinetic profiles between SB5 and Humira, and showed comparable efficacy, safety, and immunogenicity profiles. SB5 is set to become a leading biosimilar for this debilitating, chronic condition, with a global sales forecast of $832 million by 2029, according to GlobalData.
Mariam Shwea, Healthcare Analyst at GlobalData, comments, “SB5 is welcomed for its trailblazing nature, as the reported Phase IV interchangeability data are encouraging, suggesting that the biosimilar could be a valuable option for patients with PsO. SB5 is already approved in the US and Europe, and these positive results could help boost its adoption in other markets.”
The efficacy of SB5 was reinforced by a randomised, double-blind, parallel-group, multiple-dose, active comparator, multicenter Phase IV (NCT05510063) clinical trial, which evaluated pharmacokinetic similarity in patients with moderate-to-severe PsO switching between Humira and high-concentration SB5, compared to those consistently using Humira.
Post the 13-week period, patients who achieved at least a 50 per cent reduction in Psoriasis Area and Severity Index (PASI50) were randomized to switch between adalimumab and SB5 or continue with adalimumab, in a 1:1 ratio. The study achieved its primary endpoints, centered around pharmacokinetic measures (AUCtau and Cmax) during Weeks 23-25.
Additionally, both groups exhibited comparable efficacy, safety, and immunogenicity profiles. Comparing the multiple-switching group and the Humira-continued group for primary endpoints, the 90 per cent confidence intervals (CI) were entirely within pre-defined margins. The 90 per cent CI for the ratio of geometric least squares mean of AUCtau for Week 23-25 (0.8007, 1.1115) and for Cmax (0.8637, 1.1433) were both within the pre-defined margin of 0.8 and 1.25.
Shwea adds, “The potential availability of an interchangeable biosimilar to Humira will be good news for patients with this chronic disease, offering them a more affordable and convenient treatment option. SB5 is available in a prefilled syringe and prefilled autoinjector, which makes it easy to self-administer. However, indirect comparisons should be made with caution due to differences in clinical trial designs and patient populations and it is important to note that while the press release highlighted topline results from the interchangeability study, SB5 has not officially received interchangeability designation at this time. Moreover, SB5’s effectiveness is yet to be established in patients who have lost response to or were intolerant to TNF blockers.”
Humira’s 52-week study evaluated adalimumab’s efficacy and safety for moderate-to-severe psoriasis, exploring continuous against interrupted therapy based on a PASI 75 score improvement and in relation to a placebo group (NCT00237887). SB5’s Phase IV trial focused on the pharmacokinetics, efficacy, and safety of SB5 against Humira in the same moderate-to-severe population, using a switch protocol at Week 13 for those achieving PASI 50 reduction.
SB5 was generally well tolerated by the treatment groups. However, and as for all adalimumab products, patients are indeed at an increased risk of developing serious infections including active tuberculosis, invasive fungal infections, and bacterial, viral and other infections triggered by opportunistic pathogens.
Shwea concludes, “The prospect of SB5 achieving interchangeability with Humira represents a significant milestone in the development of biosimilars. It shows that biosimilars can be as safe and effective as their reference biologics. This opens the door to greater adoption of biosimilars, which can help to lower healthcare costs for patients with moderate-to-severe PsO, and improve patient access to effective treatments, setting a precedent for other biosimilars.”