Efficacy and Safety of SSGJ-608 in Moderate-to-Severe Plaque Psoriasis: A Pivotal Multicenter, Double-Blind, Placebo-Controlled, Randomized, Phase III Clinical Trial

SSGJ-608 is a recombinant, humanized, immunoglobulin G1 monoclonal antibody that targets human interleukin-17A with high specificity and high affinity. We aimed to evaluate the efficacy and safety of SSGJ-608 in patients with moderate-to-severe psoriasis in China. Adult patients aged 18 years or older with moderate-to-severe plaque psoriasis were randomly assigned (2:2:1) to receive subcutaneous injections of placebo (placebo group), 80 mg of SSGJ-608 every 2 weeks after a starting dose of 160 mg at week 0 (608A group), or 160 mg of SSGJ-608 every 4 weeks (608B group). At week 12, patients in the 608A group received SSGJ-608 80 mg every 4 weeks, patients in the 608B group received SSGJ-608 160 mg every 8 weeks, and patients in the placebo group were re-allocated (1:1) to either the 608A or 608B group to receive 608 80 mg every 4 weeks (with an additional 160-mg loading dose of SSGJ-608 at week 12) or 160 mg every 8 weeks. All patients received treatment until week 48. The primary endpoints were a ≥75% improvement from baseline in the Psoriasis Area and Severity Index score (PASI75) and a static Physicians Global Assessment score of 0/1 (sPGA 0/1) at week 12. A total of 458 patients were randomly assigned to either the 608A group (n = 184), the 608B group (n = 183), or the placebo group (n = 91). At week 12, compared with those in the placebo group, a greater proportion of patients in the 608A group and in the 608B group achieved the primary endpoints of PASI75 (95.1% vs 93.4% vs 8.8%) and sPGA of 0 or 1 (76.1% vs 67.2% vs 1.1%). At week 52, PASI75 was maintained by 93.7% in the 608A group and 93.6% in the 608B group, sPGA of 0 or 1 was maintained by 89.3% in the 608A group and 89.4% in the 608B group, PASI90 was maintained by 92.6% in the 608A group and 92.5% in the 608B group, respectively. Both treatment groups demonstrated a favorable safety profile, with no increase in risk observed with longer drug exposure. SSGJ-608 showed rapid and robust clinical response at week 12 and through week 52, and was well tolerated in Chinese patients with moderate-to-severe plaque psoriasis. ClinicalTrials.gov Identifiers: NCT05536726. Psoriasis is a chronic immune-mediated skin disease affecting the global population, with plaque psoriasis being the most common variant. The primary symptoms of psoriasis include itching, dryness, irritation, and pain, which substantially diminish patients’ quality of life. SSGJ-608 is a biologic medicine developed to treat moderate-to-severe plaque psoriasis by reducing inflammation. We report final results of a phase III clinical trial evaluating the efficacy and safety of SSGJ-608 for treating plaque psoriasis. This study included 458 patients with moderate-to-severe plaque psoriasis in China and took place between 2023 and 2024. Overall, SSGJ-608 was significantly more effective than placebo at reducing psoriasis symptoms. At week 52, over 93% of patients who had achieved at least a 75% improvement in the Psoriasis Area and Severity Index score (PASI75) in their psoriasis symptoms after the first 12 weeks continued to maintain this level of improvement, whether they received treatment every 4 weeks or every 8 weeks. For the outcomes of complete skin clearance (PASI100) and near-complete skin clearance (PASI90), SSGJ-608 showed statistically greater improvements compared with placebo. Additionally, SSGJ-608 was well tolerated, with low rates of treatment discontinuation and an acceptable safety profile.

Efficacy and Safety of SSGJ-608 in Moderate-to-Severe Plaque Psoriasis: A Pivotal Multicenter, Double-Blind, Placebo-Controlled, Randomized, Phase III Clinical Trial

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