After the participant has compl eted all screening procedures, IRT will be used for treatment assignment or disc ontinuing the participant. Subsequent visits will need to be registered into t he IRT system for drug supply. Inclusion/Exclusion Criteria X Medical History XIncludes history of any toxicities or allergy relate d to previous treatments, irAEs, cardiac signs/symptoms/disease, and imm unization (eg, influenza vaccine). Prior Systemic Therapies X Tobacco History/Status X Document participant’s history and current status of tobacco use. Archived Tumor Tissue SampleXAdditional archival tumor tissue samples, if avail able, may be provided for participants in all parts as 1 paraffin block or 15-2 0 FFPE unstained slides. Samples must be shipped to central laboratory. Fresh Pretreatment Tumor BiopsyXAll participants require a mandatory pretreat ment biopsyaduring screening. Archival specimens may not be substituted for this baseline specimen (See Section 6.1 for exceptions) but can be submitte d to help understand the evolution of the tumor (ie, ICOS expression ch anges over time). Tumor tissue to be sent for assessment of tumor c ontent and ICOS expression. Revised Protocol No.: 04 Date: 31-May-2019 19 Approved 5.0 v Approved 1.0 v Clinical Protocol CA021002 BMS-986226 anti-ICOS Table 2-1: Screening Procedural Outline (CA021002) ProcedureScreening Visit (Day -28 to -1)Day -7 to -3 VisitDay -3 to -1 VisitNotes and C4D1- pre-dose. The biopsy after dose escala tion will be optional in participants in the Preliminary Safety Cohorts wh o intra-dose escalate up to 8 and/or 25 mg Safety Assessments Full Physical Exam (PE) XIf the screening physical examination is performe d within 24 hours prior to dosing on Cycle 1 Day 1, then a single examinati on may count as both the screening and pre-dose evaluation. Physical Measurements X Includes height and weight.