A recent study published in the Journal of Dermatological Treatment indicates that switching from ustekinumab to its biosimilar, SB17, maintains long-term efficacy and safety in patients with psoriasis. The findings alleviate concerns about potential adverse effects and support the broader adoption of more cost-effective treatment options.
The phase 3, randomized, double-blind, multicenter trial assessed the efficacy, safety, and immunogenicity of SB17 compared to reference ustekinumab following a switch. The study involved 503 participants with moderate to severe plaque psoriasis (PASI ≥ 12, Physician’s Global Assessment ≥ 3, and body surface area involvement ≥ 10%) across 45 centers in 8 countries from July 2021 to November 2022.
Study Design and Patient Outcomes
Participants were randomized at week 28 to either continue SB17 (SB17+SB17; n = 237), switch from ustekinumab to SB17 (UST+SB17; n = 122), or continue ustekinumab (UST+UST; n = 122). A high percentage of participants (96.9%) completed the study through 52 weeks, with balanced dropout rates across the groups (SB17+SB17, 1.7%; UST+SB17, 4.1%; UST+UST, 4.9%).
The Psoriasis Area and Severity Index (PASI) scores from baseline to week 52 were nearly identical and sustained across all treatment groups, with no signs of reduced efficacy. At week 52, the percent change of PASI was comparable among the groups (SB17+SB17, 95.8%; UST+SB17, 95.6%; UST+UST, 94.5%). Secondary efficacy endpoints from baseline to weeks 40 and 52 were also similar across all three treatment groups.
Safety Profile
The safety profiles of biosimilar SB17 and reference ustekinumab were comparable. Treatment-emergent adverse events (TEAEs) occurred in 16.5% of patients continuing SB17, 13.9% of those switching to SB17 from ustekinumab, and 23.8% of those remaining on ustekinumab. The most common TEAEs were COVID-19 and nasopharyngitis. Importantly, no injection site reactions or systemic hypersensitivity were observed after switching between medications.
Implications and Context
These findings are particularly relevant given the increasing emphasis on affordable treatment options in dermatology. The FDA has reported that generic and biosimilar medicines have generated over $3 trillion in savings for patients and the healthcare system over the past decade. While concerns have been raised about potential adverse outcomes when switching from originator biologics to biosimilars, this study provides evidence that switching from ustekinumab to SB17 does not lead to undesirable clinical outcomes.
According to the study authors, “the lack of safety issues with ustekinumab switching to SB17 should be reassuring.”
Study Limitations
The ongoing war in Ukraine disrupted some study sites; however, these disruptions were evenly distributed across treatment groups, minimizing potential bias in the results. Despite this, the authors acknowledge that their findings “may not prevent nocebo effects post-market, which may require additional efforts to mitigate.”
