A Study of Multiple Doses of RO7247669 in Participants With Previously Untreated Unresectable or Metastatic Melanoma

Inclusion Criteria:

• Histologically confirmed unresectable or metastatic melanoma, per the American JointCommittee on Cancer (AJCC) staging system (unresectable Stage III or Stage IV)

• Radiologically measurable disease according to Response Evaluation Criteria in SolidTumors (RECIST) v1.1

• Eastern Cooperative Oncology Group (ECOG) Performance Status 0-1

• Known v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) V600 mutation status

• Adequate cardiovascular, hematological, hepatic and renal function

• Willingness to abide by contraceptive measures for the duration of the study

• Participants must have known PD-L1 status

Exclusion Criteria:

• Pregnancy, lactation, or breastfeeding

• Known hypersensitivity to any of the components of RO7247669

• Participants must not have ocular melanoma

• Symptomatic central nervous system (CNS) metastases

• Significant cardiovascular/cerebrovascular disease within 6 months prior torandomization

• Known active or uncontrolled bacterial, viral, fungal, mycobacterial, parasitic, orother infection or any major episode of infection requiring treatment withintravenous (IV) antibiotics or hospitalization within 28 days prior torandomization

• Major surgical procedure or significant traumatic injury (excluding biopsies) within 28 days prior to randomization, or anticipation of the need for major surgery duringthe course of the study

• Active or history of autoimmune disease or immune deficiency with some exceptions

• Prior systemic anticancer therapy for unresectable or metastatic melanoma

• Prior anticancer therapy with any-immunomodulatory agents including CPIs (such asanti-programmed death-ligand 1[PD-L1]/PD-1 and anti-cytotoxic Tlymphocyte-associated antigen [CTLA-4]) with some exceptions if used as prioradjuvant or neoadjuvant melanoma therapies

• Prior treatment with anti-LAG3 therapy