Business Decision

This is a study to understand if taking VTX958 is safe and effective in participants diagnosed with moderate to severe psoriasis (PsO). Approximately 200 patients will take VTX958 Dose A, VTX958 Dose B, VTX958 Dose C, VTX958 Dose D, or placebo.

The study consists of a 30-day Screening Period (to see if a participant qualifies for the study), a 16-week double-blind period (a participant receives active Dose A, Dose B, Dose C, Dose D, or placebo), a 16-week Long Term Extension (LTE) period, a 36-week Open Label Extension (OLE) period and a 4-week Follow-Up Period. The maximal duration of treatment will be approximately 16 months.

Inclusion Criteria:

• Male or female participant aged 18 years or older.
• History of primarily plaque psoriasis for at least 6 months prior to the screening visit.
• Has had stable psoriasis conditions for at least 3 months before screening.
• Has moderate to severe plaque psoriasis as defined by a PASI score of ≥ 12 and an sPGA score of ≥ 3 at screening and Day 1.
• Has plaque psoriasis covering ≥ 10% of the total BSA at screening and Day 1.
• Deemed by the investigator to be eligible for phototherapy or systemic therapy.
• Females of childbearing potential must agree to use a highly effective contraceptive method from at least 4 weeks prior to Day 1 until at least 4 weeks after the last dose of study product.

Exclusion Criteria:

• Female who is breastfeeding, pregnant, lactating, or who is planning to become pregnant during the study.
• Has evidence of erythrodermic, pustular, predominantly inverse or guttate psoriasis, or drug-induced psoriasis.
• History of skin disease or presence of skin condition that, in the opinion of the investigator, would interfere with the study assessments.
• Participant is known to have immune deficiency or is immunocompromised.
• Has immune-mediated conditions commonly associated with psoriasis, such as psoriatic arthritis, active uveitis, inflammatory bowel disease, that currently require systemic treatment (including corticosteroids, immunosuppressants, or biologics).

Note: Participants with immune-mediated conditions commonly associated with psoriasis that do not require systemic treatment may be included in the study.

• Has used any topical medication that could affect psoriasis (including corticosteroids, retinoids, vitamin D analogues [such as calcipotriol], Janus kinase [JAK] inhibitors, or tar) within 2 weeks prior to Day 1.
• Has used any systemic treatment that could affect psoriasis (including corticosteroids, oral retinoids, immunosuppressive medication, anakinra, methotrexate, cyclosporine, oral JAK inhibitors, or apremilast) within 4 weeks prior to Day 1.

Note: Intranasal corticosteroids and inhaled corticosteroids are allowed. Eye and ear drops containing corticosteroids are also allowed.

• Participant has received any ultraviolet B (UVB) phototherapy (including tanning beds) or excimer laser within 4 weeks prior to Day 1.
• Participant has had psoralen and ultraviolet A (PUVA) treatment within 4 weeks prior to Day 1.
• Participant has received treatment with an investigational or marketed TYK2 inhibitor.

The study will employ a double-blind design. Subjects, Investigators, study center staff, persons performing the assessments, and the Sponsor are to remain blinded to the identity of the study treatment from the time of randomization until the database lock for the study.