- Participants in the Monotherapy Expansion Cohort must have one of the following advanced or recurrent malignancies: cutaneous melanoma showing primary progression following treatment with an anti-programmed cell death (PD) or anti-PDL1 regimen; or anti-PD1 or anti-PD-L1 treatment-naïve colorectal or gastric cancer, including gastroesophageal junction cancer of Siewert Type II and Type III.