If re-enrolled, the participant must be re-consented. 5) Age and Reproductive Status a) Males and females, ages ≥18 years at the time of informed consent. b) Women of childbearing potential (WOCBP) must have a negative serum or urine pregnancy test (minimum sensitivity of 25 IU/L or equivalent units of human chorionic gonadotropin) within 24 hours prior to the start of study treatment. c) Women must not be breastfeeding. d) WOCBP must agree to follow instructions for method(s) of contraception for the duration of study treatment with nivolumab or ipilimumab and 5 months after the last dose of study treatment (ie, 30 days [duration of ovulat ory cycle] plus the time required for the investigational drug to undergo approximately 5 half-lives). e) Males who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the durati on of study treatment with nivolumab or ipilimumab and 7 months after the last dose of study treatment (ie, 90 days [duration of sperm turnover] plus the time required for the investigational drug to undergo approximately five half-lives). In addition, male participants must be willing to refrain from sperm donati on during this time. f) Due to potential presence of study drugs in seminal fluid, azoospermic males who are sexually active must use co ndoms for all sexual activity during study treatment. Additionally, condoms must continue to be used for 4 months after the participants’ final treatment. WOCBP who are continuously no t heterosexually active are also exempt from contraceptive requirements, and st ill must undergo pregnancy testing as described in this section. Investigators shall counsel WOCBP and male participants who are sexually active with WOCBP on the importance of pregnancy prevention an d the implications of an unexpected pregnancy. Investigators shall advi se on the use of highly effective methods of contraception (seeAppendix 4 ), which have a failure rate of < 1% when used consistently and correctly. Revised Protocol No.: 04 Date: 31-May-2019 77 Approved 5.0 v Approved 1.0 v Clinical Protocol CA021002 BMS-986226 anti-ICOS 6.2 Exclusion Criteria 1) Target Disease Exceptions a) Participants with active central nervous system (CNS) metastases, untreated CNS metastases, or with the CNS as the only site of disease are excluded. However, participants with controlled brain metastases will be allowed to enroll. Controlled brain metastases are defined as no radiographic progression for at least 4 weeks following radiation and/or surgical tr eatment (or 4 weeks of observation if no intervention is clinically indicated), off steroids for at least 2 weeks, and no new or progressive neurological signs and symptoms. b) Participants with carcinomatous meningitis. 2) Prohibited Treatments a) Cytotoxic agents, unless at least 4 weeks have elapsed from last dose of prior anti- cancer therapy and initiation of study treatment. b) Non-cytotoxic agents, unless at least 4 weeks or 5 half-lives (whichever is shorter) have elapsed from the last dose of prior anti-cancer therapy and the initiation of study treatment. If 5 half-lives is shorter th an 4 weeks, agreement with the Sponsor/Medical Monitor/Study Director (or designee) is mandatory. c) Prior immunotherapy treatments, unless at leas t 4 weeks or 5 half-lives (whichever is shorter) have elapsed from the last dose of immune therapy and initiation of st udy treatment. d) Prior therapy with any agent specifically targeting T- cell co-stimulation pathways, such as anti-OX40 antibody, anti-CD137, anti-GITR antibody, and anti-CD27. e) Prior therapy with anti-ICOS antibody. f) No prior adverse reaction to tetanus toxoid-containing vaccines. g) Participants with known allergies to egg products, neomycin, or tetanus toxoid are also considered ineligible 3) Medical History and Concurrent Diseases a) Prior malignancy active within the previous 2 years except for locally curable cancers that have been apparently cured, such as basal or squamous cell skin cancer, superficial bladder cancer, or carcinoma in situ of the prostate, cervix, or breast. b) Prior organ allograft.