A Multicenter, Randomized, Double-Blind Placebo-Controlled Phase 3 Study to Evaluate the Efficacy, Safety and Pharmacokinetics of Deucravacitinib in Adolescent Subjects (12 years to less than 18 years) with Moderate to Severe Plaque Psoriasis

The primary objective of this study is to evaluate the efficacy of deucravacitinib compared to placebo in participants aged 12 to less than 18 years with moderate to severe plaque psoriasis. Efficacy assessment is based on two co-primary endpoints: achievement of PASI 75 (Psoriasis Area and Severity Index 75% improvement) and sPGA 0/1 (static Physician's Global Assessment score of 0 or 1). These endpoints represent clinically meaningful measures of disease clearance and overall disease severity reduction in adolescent patients with significant psoriatic disease burden.

The secondary objectives include:

• Assessment of deucravacitinib efficacy versus placebo using additional endpoints in the adolescent population with moderate to severe plaque psoriasis

• Evaluation of improvement in patient-reported outcomes for deucravacitinib compared to placebo

• Evaluation of the safety and tolerability of deucravacitinib in participants aged 12 to less than 18 years with moderate to severe plaque psoriasis

This clinical trial enrolled a total of **221 participants** aged **12 to less than 18 years** diagnosed with **moderate to severe plaque psoriasis**. Both **male** and **female** subjects were included in the study population. The trial specifically recruited adolescents who had experienced stable **plaque psoriasis** for at least 6 months prior to enrollment. Participants were required to be candidates for **systemic therapy** or **phototherapy**, indicating that their condition warranted treatment beyond topical interventions alone. The study population was classified as a **vulnerable population** due to the pediatric age range of the enrolled subjects.

This is a multicenter, **randomized**, **double-blind**, **placebo-controlled** **Phase 3** clinical trial designed to evaluate the efficacy, safety, and **pharmacokinetics** of **deucravacitinib** in adolescent participants aged 12 years to less than 18 years with **moderate to severe plaque psoriasis**. The investigational medicinal product, deucravacitinib, is administered as **film-coated tablets** via the **oral route**. Matching **placebo** formulations are used as comparators to ensure blinding. The trial includes both a short-term evaluation period and a long-term extension phase. The maximum treatment period is 68 weeks. The overall trial duration extends from the estimated recruitment start date in September 2025 to the estimated end date in September 2034.

The primary objective is to evaluate the efficacy of deucravacitinib versus placebo based on two **co-primary endpoints** assessed at Week 16. These endpoints are the proportion of participants achieving at least 75% improvement in **Psoriasis Area and Severity Index** (**PASI 75**) and the proportion achieving a **static Physician's Global Assessment** (**sPGA**) score of 0 (clear) or 1 (almost clear) with at least a 2-point reduction from baseline. Secondary efficacy endpoints include the proportion of participants achieving at least 90% improvement in PASI (**PASI 90**) at Week 16, change from baseline in PASI at Week 16, and change from baseline in **body surface area** (**BSA**) involvement at Week 16. Long-term extension efficacy endpoints assess PASI 75 and sPGA 0/1 responses over time through study completion.

Safety is evaluated through monitoring of **adverse events** (**AEs**) and **serious adverse events** (**SAEs**), laboratory parameters, physical examination, and vital signs throughout the study. Specific safety assessments include evaluation of participants with protective titers of antibodies to measles, tetanus, and pertussis at Week 16. Growth monitoring, including body weight and height, as well as sexual maturation, is conducted through study completion in both the initial treatment period and the long-term extension.

Eligible participants are adolescents aged 12 to less than 18 years with moderate to severe stable plaque psoriasis for at least 6 months who are candidates for systemic therapy or phototherapy. The study involves a series of scheduled visits including screening, baseline, treatment visits, and follow-up assessments. The primary efficacy and safety evaluations occur at Week 16, with continued monitoring throughout the long-term extension phase. Participant involvement extends up to the maximum treatment period of 68 weeks, with the possibility of early termination based on predefined study discontinuation criteria, safety concerns, or withdrawal of consent.

The experimental medication utilized in this clinical trial is **deucravacitinib**, identified by the sponsor product code BMS-986165. Deucravacitinib is supplied as **film-coated tablets** for **oral** administration. The active substance is deucravacitinib, a chemical entity. The maximum treatment period for deucravacitinib administration is 68 weeks. The medicinal product is manufactured by Bristol-Myers Squibb International Corporation.

Two **placebo** formulations are employed in this study to match the experimental medication and maintain blinding integrity. The first placebo formulation is designed to match deucravacitinib 2mg minitablets and is provided in sachet form for oral use. The second placebo formulation is designed to match deucravacitinib 6mg tablets and is supplied in bottle form for oral use. Both placebo formulations are administered via the **oral route** and are utilized for a maximum treatment period of 68 weeks, corresponding to the duration of active treatment.

The study employs a **double-blind**, **placebo-controlled** design to evaluate the efficacy and safety of deucravacitinib compared to placebo in adolescent participants aged 12 years to less than 18 years with moderate to severe **plaque psoriasis**. The randomized treatment allocation ensures comparable groups for assessment of the primary efficacy endpoints, including PASI 75 response and sPGA score of 0 or 1.

Efficacy will be assessed using two co-primary endpoints measured at Week 16. The first co-primary endpoint is the proportion of participants achieving at least 75% improvement in Psoriasis Area and Severity Index (PASI 75) at Week 16. The second co-primary endpoint is the proportion of participants achieving a static Physician's Global Assessment (sPGA) score of 0 (clear) or 1 (almost clear) with at least a 2-point reduction from baseline at Week 16.

Secondary efficacy endpoints include the proportion of participants achieving at least 90% improvement in PASI (PASI 90) at Week 16, change from baseline in PASI at Week 16, and change from baseline in body surface area involvement at Week 16. During the long-term extension phase, efficacy will be evaluated by assessing the proportion of participants achieving PASI 75 over time through study completion and the proportion of participants achieving an sPGA score of 0 (clear) or 1 (almost clear) with at least a 2-point reduction from baseline over time through study completion.