Samsung Bioepis Co Ltd (Samsung Bioepis) and Organon & Co (Organon) announced on August 1 their latest clinical trial results evaluating SB5, a biosimilar of the reference tumour necrosis factor (TNF) blocker Humira (adalimumab), approved by the FDA under the brand name Hadlima (adalimumab-bwwd), in terms of interchangeability. The Phase IV clinical trial focused on patients with moderate-to-severe chronic plaque psoriasis (PsO), and based on the disclosed topline findings, SB5 met primary objectives and secondary benchmarks, indicating comparable pharmacokinetic profiles for patients switching between SB5 and AbbVie’s Humira. The study also established comparable efficacy, safety, and immunogenicity profiles between the two treatment groups, suggesting SB5’s potential to offer a valuable alternative in the treatment landscape for PsO (Organon, press release, August 1, 2023).

According to an article by Damiani and colleagues in Frontiers in Medicine, PsO is a systemic immune-mediated dermatological condition, which affects 2%–3% of the world’s population and is linked to physical effects and debilitated quality of life. Just as Humira revolutionised treatment, Samsung Bioepis and Organon’s SB5 offers promise in the realm of biosimilars.

The efficacy of SB5 was reinforced by a randomized, double-blind, parallel-group, multiple-dose, active-comparator, multicenter Phase IV (NCT05510063) clinical trial spanning 33 sites across Bulgaria, Czechia, Lithuania, and Poland, which evaluated pharmacokinetic similarity between patients with moderate-to-severe PsO switching between Humira and high-concentration SB5, compared to those consistently using Humira. All 371 participants were new to Humira and were administered the drug during a 13-week introductory period. After the 13-week period, patients who achieved at least a 50% reduction in Psoriasis Area and Severity Index (PASI 50) were randomized to switch between adalimumab and SB5 or continue with adalimumab, in a 1:1 ratio. The study achieved its primary endpoints, centred 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 (AUCtau, 23–25 week, and Cmax, 23–25 week), the 90% confidence intervals (CI) were entirely within pre-defined margins. The 90% 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.

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, it is important to note that while the press release highlighted topline results from the interchangeability study, it is crucial to clarify that SB5 has not officially received interchangeability designation at this time. Nonetheless, 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 and improve patient access to effective treatments.

According to GlobalData’s Pharma Intelligence Center Drugs Database, with an analyst consensus global sales forecast of $832 million by 2029, SB5’s interchangeable status with Humira offers it the opportunity to differentiate itself from other biosimilars. Preliminary data suggests that it may have a similar efficacy and safety profile to AbbVie’s drug. However, indirect comparisons should be made with caution due to differences in trial design and patient populations. 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 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. Overall, GlobalData understands that the positive clinical trial results highlight SB5’s potential to become a transformative therapy for moderate-to-severe PsO, setting a precedent for other biosimilars.