Stelara Biosimilar SYSA1902 Shows Clinical Equivalence for Plaque Psoriasis

In a phase 3 study, SYSA1902 (CSPC Pharmaceutical Group), a biosimilar of ustekinumab, was found to be clinically equivalent to its reference product, Stelara (Janssen Biotech), when treating moderate to severe plaque psoriasis. These positive findings can potentially lead to an FDA approval.¹

Ustekinumab is a monoclonal antibody used to manage and treat a variety of inflammatory conditions, such as psoriasis, psoriatic arthritis, and inflammatory bowel disease (IBD). The treatment is available for injection in prefilled syringes and vials, and is administered by either subcutaneous or intravenous infusions. The dosage and administration recommendations depend on the particular indication for treatment and the patient's weight.²

Ustekinumab mediates the body's T-cell response by acting as an antagonist against IL-12 and IL-23. The drug is FDA-approved for use in moderate to severe plaque psoriasis, particularly in those patients who are candidates for phototherapy or systemic therapy, aged 6 years or older. Patients with active psoriatic arthritis (PsA) may use ustekinumab as monotherapy or in combination with methotrexate. More recently, ustekinumab has been approved for moderate to severely active Crohn disease and ulcerative colitis.²

Although ustekinumab has not received FDA approval for other inflammatory-mediated diseases, it has been used off-label for the treatment of hidradenitis suppurativa, Takayasu arteritis, giant cell arteritis, Behçet disease, atopic dermatitis, and systemic lupus erythematosus, among others.²

The purpose of this study, which was published in Journal of the American Academy of Dermatology, was to evaluate the efficacy and safety of SYSA1902 compared with its reference product, Stelara, in the treatment of Chinese patients with moderate to severe plaque psoriasis. The eligible 446 patients were randomly assigned to receive either the biosimilar (n = 224) or its reference product (n = 222). Each patient received 45 mg of their assigned treatment subcutaneously at weeks 0, 4, 16, 28, 40, and the primary end point was percentage improvement from baseline in psoriasis area and severity index (PASI) at week 12.¹

The findings demonstrated that, at week 12, the mean percentage change from baseline in PASI was approximately 86.4% and 84.7% in the SYSA1902 and Stelara groups, respectively, with a difference of about 1.68% (95% CI –1.45 to 4.81). This fell within the equivalence margins, according to the investigators. Additionally, PASI 75 at week 12 was achieved by about 83.3% (n = 185) of patients receiving SYSA1902 compared with 79.3% (n = 172) of those treated with Stelara.¹

Overall treatment-emergent adverse events (TEAEs) rate was 89.3% and 85.6% in the SYSA1902 and Stelara groups. Most TEAEs observed were considered mild to moderate, with upper respiratory tract infection being the most common.¹

The limitation expressed by the authors is the lack of generalizability, as the data are limited to Chinese patients.¹ However, with these positive findings, SYSA1902 may be another biosimilar to Stelara to join the currently FDA-approved options, including Ustekinumab-stba (Steqeyma; Celltrion), ustekinumab-hmny injection (Starjemza; Bio-Thera Solutions, Hikma Pharmaceuticals), ustekinumab-stba (Steqeyma; Celltrion), and ustekinumab-kfce (Yesintek; Biocon Biologics), among others.

“Compared with [Stelara], SYSA1902 exhibited a generally lower immunogenicity profile, with the same difference observed in the other biosimilars. Given that the efficacy and safety were similar between SYSA1902 and [Stelara], it suggested that the immunogenicity might have not much effect on the efficacy and safety,” wrote the study authors. “In summary, SYSA1902 demonstrated clinical equivalence to [Stelara] in terms of efficacy, safety, pharmacokinetics, and immunogenicity in patients with moderate ot severe plaque psoriasis.”¹

REFERENCES

1. Xia L, Miao G, Yang X, et al. Efficacy and safety of SYSA1902 versus reference ustekinumab in moderate-to-severe plaque psoriasis: a multicenter, randomized, phase III study. J Am Acad Dermatol. 2025;93(1):115-123. doi:10.1016/j.jaad.2025.03.018

2. Colquhoun M, Kemp AK. Ustekinumab. Updated March 27, 2023. Accessed October 3, 2025. https://www.ncbi.nlm.nih.gov/books/NBK570645/