This is a first-in-human, randomized, double- blind, placebo-controlled, dose escalation study to investigate how different doses of CAN10 are tolerated, taken up by the body and how long CAN10 stays in the body. In the first part of the study, the single ascending dose (SAD) cohorts, CAN10 will be given as a single intravenous dose to healthy subjects. In the second part of the study, the multiple ascending dose (MAD) cohorts, CAN10 will be given as repeated subcutaneous doses to participants with mild to moderate plaque psoriasis.

Inclusion Criteria:

• Male or female, aged 18 to 50 years of age (inclusive) at the time of signing informed consent.
• Body mass index (BMI) 18 to 30 kg/m2 (inclusive) and a weight between 50 to 100 kg (inclusive) at the time of screening
• Considered by the investigator to be in good general health as determined by medical history, clinical laboratory test results, vital sign measurements, 12-lead ECG results, and physical examination findings at screening.
• Female subjects of childbearing potential must use a highly effective method of birth control and have a negative pregnancy test at screening and before the first dose of study drug. Male subjects with female partners must agree to use a condom, and their female partners are recommended to use a highly effective method of birth control.

Additionally for subjects with plaque psoriasis only:

• A diagnosis of plaque psoriasis with Psoriasis Area Severity Index (PASI) score ≥3 to ≤15 and Physician Global Assessment (PGA) score ≥2 (mild) to <4 (moderate).
• No disease manifestation requiring systemic immunosuppressive therapy.

Exclusion Criteria:

• History or presence of:

  1. Severe allergy/hypersensitivity (subjects with mild pollen allergy can be included).
  2. Significant kidney, liver, or urologic disease.
  3. Clinically significant psychiatric disorders
  4. Tuberculosis (TB) infection or positive QuantiFERON TB Gold test
  5. Any other clinically significant disease or disorder which, in the opinion of the investigator, may either put the subject at risk because of participation in the study, or influence the results or the subject's ability to participate in the study.

• Clinically significant illness, medical/surgical procedure, or trauma within 4 weeks before the first dose of study drug.

• Ongoing opportunistic or systemic infections

• A positive test result for hepatitis B surface antigen, hepatitis C virus antibody, or human immunodeficiency virus antigen or antibodies at screening.

Additionally for subjects with plaque psoriasis only:

• Psoriasis other than a plaque variant.

• Any sign of infection of any of the psoriatic lesions.

• Use of any of the following treatments within the indicated washout period before the first dose of study drug:

  1. 12 weeks or 5 half-lives (whichever is longer) for biologic agents known or expected to impact the course of psoriasis or its assessments.
  2. 12 weeks for oral retinoids
  3. 8 weeks for cyclosporin, interferon, methotrexate, other systemic immunosuppressive or immunomodulating agents, or psoralen plus ultraviolet A (UVA)
  4. 2 weeks for immunizations or drugs known to possibly worsen psoriasis, unless on a stable dose for >12 weeks
  5. 1 week for topical treatments: corticosteroids, immunomodulators, anthralin (dithranol), Vitamin D derivatives, retinoids, or coal tar (used on the body)