Data Confirm Biosimilar Bmab 1200 Performance in Psoriasis Through 1 Year

Demonstrating treatment consistency over a full year, the latest clinical data confirmed that the ustekinumab biosimilar Bmab 1200 was equivalent to the reference product in treating moderate to severe plaque psoriasis.

The phase 3 STELLAR-2 trial (NCT05484024) successfully demonstrated that Bmab 1200, a biosimilar candidate referencing ustekinumab, showed equivalent efficacy, comparable safety, and a similar immunogenicity profile to the reference product over 52 weeks in adults with moderate to severe chronic plaque psoriasis. The data package supported the use of Bmab 1200 as an alternative treatment option, including for people who transitioned from the reference ustekinumab.

Rationale and Study Design

The primary objective of the STELLAR-2 trial was to meet regulatory requirements by establishing the equivalent efficacy of Bmab 1200 and the reference ustekinumab (Stelara). This randomized, double-blind, active-controlled study was essential for confirming biosimilarity following extensive analytical and pharmacokinetic comparisons.

The study included a crucial re-randomization step at week 16. After an initial treatment period (TP1) where people received either Bmab 1200 or reference ustekinumab, responders in the reference ustekinumab arm were re-randomized to either continue the reference product or switch to Bmab 1200 for the remainder of the study (TP2), allowing for an evaluation of safety and efficacy after transition.

Key Efficacy and Safety Outcomes

The study tracked 384 adult patients. The primary efficacy endpoint was the percentage change from baseline in the Psoriasis Area and Severity Index (PASI) score at week 12. Bmab 1200 met the predefined equivalence margin, confirming initial therapeutic similarity.

52-week Data on Efficacy: The 52-week findings confirmed consistent treatment responses across all cohorts. The mean percentage reduction in PASI scores from baseline was highly consistent at the final assessment:

• Bmab 1200 (maintenance): –95.5%
• Reference Ustekinumab (continued): –96.6%
• Switched-to-Bmab 1200 (at week 16): –94.7%

These results affirmed that the efficacy was maintained through one year, even following the switch from the reference drug to the biosimilar. Secondary efficacy endpoints, including the Physician’s Global Assessment and Dermatology Life Quality Index scores, also showed comparable improvements.

Safety and Immunogenicity: The safety profile of Bmab 1200 was consistent with the known profile of the reference product. The incidence of treatment-emergent adverse events (TEAEs) and their severity were similar across treatment groups. Crucially, the immunogenicity profile, indicated by the incidence of anti-drug antibodies (ADAs), was also comparable after the switch.

The authors noted the clinical relevance of the comprehensive data package, stating, "The study reinforces the confidence we can have in the biosimilar regulatory pathways and the principles they are built on. Specifically, for Bmab 1200, the study shows that it offers an effective, safe, and comparable alternative to reference ustekinumab."

Patient Population and Study Limitations

The STELLAR-2 trial enrolled 384 adult participants diagnosed with moderate to severe chronic plaque psoriasis. The inclusion criteria required people to be 18 years of age or older with defined disease severity metrics (eg, specific PASI score and affected body surface area). The study was conducted as a multinational, multicenter trial.

Standard limitations applicable to this phase 3 trial included:

1. Limited Long-Term Follow-Up: The study duration was 52 weeks. Further long-term data would be beneficial for chronic conditions requiring indefinite treatment.
2. Specific Patient Population: The trial was limited to people with moderate to severe plaque psoriasis, and the results require extrapolation to cover the other ustekinumab indications (eg, Crohn disease or psoriatic arthritis).
3. Controlled Setting: As a clinical trial, the results represented a controlled patient environment and may vary slightly in broader real-world populations with more diverse comorbidities.

In summary, the STELLAR-2 trial successfully confirmed that Bmab 1200 was highly similar to reference ustekinumab in terms of efficacy, safety, and immunogenicity over 52 weeks, supporting its clinical use across all tested cohorts, including those who transitioned treatment.

Reference

Szepietowski JC, Reich A, Feldman SR, et al. Comparative efficacy and safety of biosimilar Bmab 1200 versus reference ustekinumab in moderate-to-severe plaque psoriasis: 52-week findings from the phase 3 STELLAR-2 trial. Expert Opin Biol Ther. Published online October 21, 2025. doi:10.1080/14712598.2025.2576506