• Primary non-metastatic UM, except iris melanoma, after definitive treatment either by surgery or radiotherapy

• Time from primary treatment smaller than 11 weeks (note that the maximum time between primary treatment and randomization is 12 weeks )

• High-risk according to either 1) clinical criteria: TNM (AJCC8) stage III or 2) genetic criteria: monosomy 3 or GEP class 2. Prior to enrolment of the first patient, each site will declare which of the two genetic criteria it uses. Patients with stage I and stage II are only eligible if they meet the genetic criterion declared by the site.

• ECOG performance status of 0 or 1

• 18 years or older

• HLA-A\*02:01 positivity by local assessment

• No evidence of UM recurrence, as evidenced by the required baseline imaging performed within 4 weeks prior to randomization

• Adequate organ function

• Time-interval between the end of primary treatment and the randomization less than or equal to 12 weeks

• Evidence of post-menopausal status or negative urinary or serum pregnancy test for women of childbearing potential (WOCBP) within 3 days prior to randomization.

• For patients of childbearing / reproductive potential, agreement to use adequate birth control measures during the study treatment period and for at least 6 months after the last dose of treatment. A highly effective method of birth control is defined as a method which results in a low failure rate (i.e., less than 1% per year) when used consistently and correctly.

• For female subjects who are breast feeding, agreement to discontinue nursing prior to the first dose of study treatment and until 6 months after the last study treatment.

• Written informed consent according to ICH/GCP and local regulations