A multicenter phase 3 trial has demonstrated that switching from ustekinumab to its biosimilar SB17 maintains long-term efficacy and safety in patients with moderate to severe plaque psoriasis, potentially expanding access to more affordable treatment options.
Clinical Efficacy and Safety Outcomes
The randomized, double-blind study involved 503 participants across 45 centers in eight countries, including the Czech Republic, Estonia, Hungary, and the Republic of Korea. Patients were required to have a Psoriasis Area and Severity Index (PASI) score of at least 12, a Physician's Global Assessment of 3 or higher, and body surface area involvement of 10% or more at screening.
At week 28, 481 patients were randomized into three groups: continuation of SB17 (n=237), switching from ustekinumab to SB17 (n=122), or continuation of ustekinumab (n=122). The study achieved a remarkable completion rate of 96.9% through week 52, with balanced dropout rates across all treatment arms.
Comparable Treatment Outcomes
The results showed nearly identical PASI improvements across all treatment groups by week 52:
- SB17 continuous group: 95.8% improvement
- Ustekinumab to SB17 switch group: 95.6% improvement
- Ustekinumab continuous group: 94.5% improvement
Secondary efficacy endpoints remained comparable across all three treatment groups from baseline through weeks 40 to 52.
Safety Profile and Adverse Events
The safety analysis revealed comparable profiles between SB17 and reference ustekinumab. Treatment-emergent adverse events (TEAEs) were observed in:
- 16.5% of patients continuing SB17
- 13.9% of patients switching to SB17
- 23.8% of patients remaining on ustekinumab
COVID-19 and nasopharyngitis were the most frequently reported adverse events. Importantly, no injection site reactions or systemic hypersensitivity were observed following treatment switches.
Economic Impact and Market Implications
The findings come at a significant time, as the FDA reports that generic and biosimilar medicines have generated over $3 trillion in savings for patients and healthcare systems over the past decade. Both U.S. and European regulatory authorities have approved SB17 for treating plaque psoriasis, psoriatic arthritis, and inflammatory bowel disease.
Study Limitations
While the ongoing conflict in Ukraine disrupted some study sites, researchers noted that these disruptions were evenly distributed across treatment groups, minimizing potential bias in the results. The study authors acknowledged that while nocebo effects may still occur in post-market settings, the demonstrated safety profile of switching from ustekinumab to SB17 should provide reassurance to healthcare providers and patients.
