Following each treatment cycle, the decision to treat a participant with additional cycles of study treatment (up to a maximum of 24 weeks), w ill be based on safety and tolerability and tumor a ssessments performed every 8 weeks ( ±1 week). •Part B1: Combination therapy will consist of BMS- 986226 administered every 12 weeks (Q12W) + nivolumab 480 mg administered in 4-week cycles for up to 2 years of treatment. Following each tr eatment cycle, the d ecision to tr eat a participant with additional cycles of study treatment, w ill be based on safety and tolerability and tumor assessments performed every 8 weeks ( ±1 week). •Part B2: Combination therapy will consist of BMS-986226 administered every 4 weeks (Q4W) + nivolumab 480 mg administered in 4-week cycles for up to 2 years of treatment. Following each treatment cycle, the d ecision to treat a participant with additional cycles of st udy treatment, w ill be based on safety, tolerability, and tumor assessments pe rformed every 8 weeks ( ±1 week). •Part C1: Combination therapy will consist of BMS-986226 administered every 12 weeks (Q12W) + ipilimumab 3 mg/kg Q4W for up to 2 years of treatment. Following each treatment cycle, the decision to treat a participant with additional cycles of study treatment, will be based on safety, tolerability, and tumor a ssessments performed every 8 weeks ( ±1 week). •Part C2: Combination therapy will consist of BMS-986226 administered every 4 weeks (Q4W) + ipilimumab 3 mg/kg Q4W for up to 2 years of treatment. Following each treatment cycle, the decision to treat a participant with additional cycles of study treatment, w ill be based on safety, tolerability, and tumor assessments performed every 8 weeks ( ±1 week). The treatment phase in the Preliminary Safety Cohor t and Part A consists of up to six 4-week treatment cycles (1 cycle = 28 days). In the Preliminary Safety Cohort and Part A, each treatment cycle will consist of BMS-986226 monotherapy for a total of 24 weeks. In Parts B1 and C1, 4 week cycles will be use d, such that BMS-986226 + nivolumab or ipilimumab will be admin istered starting on Cycle 1 Day 1. Nivolu mab and ipilimumab will be administered on Day 1 of each cycle. BMS-986226 will be administered Q12W , or on Day 1 of every third cycle Revised Protocol No.: 04 Date: 31-May-2019 16 Approved 5.0 v Approved 1.0 v Clinical Protocol CA021002 BMS-986226 anti-ICOS (Cycle 1 Day1, Cycle 4, Day1, Cycle 7 Day1, etc.). Participants on Parts B1 and C1 may continue treatment for up to a total of 2 years. The treatment phase in Parts B2 and C2 will consist of BMS-986226 + nivolumab or ipilimumab administered on Day 1 of each cycle for up to a total of 2 years. Participants in Parts B2 and C2 will be enrolled if additional safety, PK, or PD data is required to op timize dose and/or schedule selection. Follow-up: Safety follow-up will occur 30, 60, and 100 days ( ±7 days) after either the last dose or the date of discontinuation. All participants treated with monotherapy or combination therapy will enter the survival follow-up period after the last safety visit. All participants treated with monotherapy or combination therapy with ongoing stable disease (SD), partial response (PR), or complete response (CR) w ill enter the response follow-up period after the last safety visit. If the participant discontinues treatment for any reason other than PD, radiological follow-up will continue until the participant receives additional treatment. The duration of this phase is up to 2 years from the last dose of study tr eatment, although a longer follow-up period could be considered in selected cases if an efficacy signal is apparent. S urvival follow-up will cont inue approximately every 3 months (12 weeks) un til death, loss to follow-up or subsequent treatment, withdrawal of consent, or conclusion of the study, whichever comes first. Participants who have disease progression following the initial course of study treatment w ill not be evaluated for respons e beyond the end of treatment visit and will be allowed to receive other tumor-directed therapy as required. A study design schematic is provided in Figure 1-1. Figure 1-1: Study Design Schematic * Note: Arms B2 and C2 will enroll only if additional safety, PK, and PD data are required to inform dose expansion decisions. The dose levels assessed in B2 and C2 will not exceed those evaluated in Part A, B1, or C1. Abbreviations: CC = cervical cancer ; CRC = colorectal carcino ma; HNSCC = head and n eck squamous cell carcinoma; MEL = melanoma; NSCLC = non-small-cell lung cancer; RCC = r enal cell carcinoma; PRC = adenocarcinoma of the prostate; RD = receptor downregulated; TNBC = triple negative breast cancer; UCC = urothelial carcinoma. Revised Protocol No.: 04 Date: 31-May-2019 17 Approved 5.0 v Approved 1.0 v Clinical Protocol CA021002 BMS-986226 anti-ICOS Study treatment: Study Treatment for CA021002 Medication Potency IP/Non-IP BMS-986226-01 10 mg/mL IP Nivolumab 10 mg/mL IP Ipilimumab 5 mg/mL IP Tetanus vaccine Per locala IP aTetanus vaccine (Tdap preferred, Td or equivalent after discussion with the Study Director/Medical Monitor (or designee)) will be obtained as local co mmercial product in countries if allowed by local regulations or through investigating sites standard prescribing procedures.