SYSA1902 Biosimilar Proves Equivalent to Reference Ustekinumab in Plaque Psoriasis

A new biosimilar may offer a treatment option for patients with moderate-to-severe plaque psoriasis. SYSA1902, a biosimilar of ustekinumab, was found to be clinically equivalent to its reference product, Stelara (Janssen), in a phase 3 study.¹ The findings were detailed in a multicenter, randomized study that provides information on the biosimilar's efficacy and safety profile.

Psoriasis. | Image Credit: Daniel Beckemeier - stock.adobe.com .jpeg

In the US, there are 8 FDA-approved ustekinumab biosimilars, most of which launched on the market in 2025.² Although the market is still new worldwide, ustekinumab biosimilars provide patients with new options at steep discounts, expanding access to rheumatology and immunology medications.

The study's purpose was to compare the efficacy and safety of SYSA1902 with reference ustekinumab in patients with moderate to severe plaque psoriasis.¹ The primary endpoint was the percentage improvement from baseline in the Psoriasis Area and Severity Index (PASI) at week 12. Equivalence was established if the 95% confidence interval of the difference in PASI improvement was within 15%.

A total of 446 patients were enrolled at 42 sites in China. Patients were randomized to receive either SYSA1902 (n = 224) or ustekinumab (n = 222). Patients received a 45 mg subcutaneous injection at weeks 0, 4, 16, 28, and 40. The study's authors noted a limitation that the data were specific to Chinese patients.

The study's findings showed that the 2 treatments were comparable in efficacy and safety. At week 12, the mean percentage change from baseline in PASI was 86.4% in the SYSA1902 group and 84.7% in the ustekinumab group. The difference was 1.68%, with a 95% confidence interval of –1.45% to 4.81%, which was within the equivalence margins. Additionally, 83.3% of patients receiving SYSA1902 achieved a PASI 75 score at week 12, compared to 79.3% of those in the ustekinumab group. Secondary efficacy endpoints also indicated a similarity between the treatments.

The safety analysis indicated similar rates of adverse events. The overall rate of treatment-emergent adverse events was 89.3% in the SYSA1902 group and 85.6% in the ustekinumab group. Most of these events were mild to moderate, and upper respiratory tract infection was the most common. Pharmacokinetic profiles and anti-drug antibody positivity were also similar between the 2 groups.

According to the authors of the study, "Our findings indicated that the efficacy of SYSA1902 and ustekinumab were similar in the PASI 75 response rate, and other second efficacy endpoints, which resulted in a significantly improved symptoms and quality of life in patients with moderate-to-severe psoriasis.". The authors stated that additional studies would be conducted to evaluate the efficacy and safety of SYSA1902 in a more diverse patient population.

The results of this phase 3 trial add to the data on biosimilars for the treatment of plaque psoriasis. As biosimilar products continue to become available, they may offer additional treatment options for patients.

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. Jeremias S. FDA approves Steqeyma for children with plaque psoriasis, psoriatic arthritis. The Center for Biosimilars^®. May 27, 2025. Accessed September 4, 2025. https://www.centerforbiosimilars.com/view/fda-approves-starjemza-as-new-stelara-biosimilar