An Adverse Event (AE) is defined as any new untoward medical occurrence or worsening of a preexisting medical condition in a clinical investigation participant administered study treatment and that does not necessarily have a causal relationship with this treatment.

All treated participants

Serious Adverse Event (SAE) is defined as any untoward medical occurrence that, at any dose results in death, is life-threatening (defined as an event in which the participant was at risk of death at the time of the event; it does not refer to an event which hypothetically might have caused death if it were more severe), requires inpatient hospitalization or causes prolongation of existing hospitalization.

All treated participants

An Adverse Event (AE) is defined as any new untoward medical occurrence or worsening of a preexisting medical condition in a clinical investigation participant administered study treatment and that does not necessarily have a causal relationship with this treatment. Dose limiting toxicity (DLT) is defined based on the incidence, intensity, and duration of AEs for which no clear alternative cause is identified. The DLT period will be 28 days (4 weeks) in the Preliminary Safety Cohorts. Any toxicities that occur beyond the 4-week DLT period will also be considered in dose-level decisions. For the purpose of participant management, any AE that meets DLT criteria, regardless of the cycle in which it occurs, will lead to discontinuation of study treatment. AEs will be graded according to the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) v4.03.

All treated participants

An Adverse Event (AE) is defined as any new untoward medical occurrence or worsening of a preexisting medical condition in a clinical investigation participant administered study treatment and that does not necessarily have a causal relationship with this treatment.

All treated participants

An Adverse Event (AE) is defined as any new untoward medical occurrence or worsening of a preexisting medical condition in a clinical investigation participant administered study treatment and that does not necessarily have a causal relationship with this treatment.

All treated paricipants

The number of participants experiencing abnormal laboratory results of Grade 3 or higher. Laboratory values will be graded according to National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) v4.03 with Grade 3=severe and Grade 4=life threatening.

All treated participants

ORR is defined as the percentage of all treated participants whose best overall response (BOR) is either complete response (CR) or partial response (PR) as assessed by investigator per RECIST v1.1. CR is defined as the disappearance of all target and non-target lesions. Any pathological lymph nodes (whether target or non-target) must also have reduction in the short axis to < 10 mm. PR is defined as at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. BOR for a participant is defined as the best response designation recorded between the date of first dose (or date of randomization) and the date of first objectively documented progression per RECIST 1.1 or the date of subsequent therapy, whichever occurs first.

All treated participants

DOR for a participant with confirmed response is defined as the time from the date of first response CR or PR to the date of first objectively documented tumor progression as determined using RECIST v1.1 or death due to any cause, whichever occurs first. Participant who remain alive and have not progressed will be censored on the date of their last tumor assessment. Participants who started subsequent anticancer therapy without a prior reported progression will be censored at the last tumor assessment prior to initiation of the subsequent anticancer therapy. CR is defined as the disappearance of all target and non-target lesions. Any pathological lymph nodes (whether target or non-target) must also have reduction in the short axis to < 10 mm. PR is defined as at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters.

All treated participants with complete response (CR) or partial response (PR)

The PFSR is defined as the Kaplan Meier estimate of percentage of treated participants remaining progression free and surviving at the prespecified timepoint of 24 weeks since the first dosing date. Progressive Disease (PD) is defined as at least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. (Note: The appearance of 1 or more new lesions is also considered progression.)

All treated participants

ADA for BMS-986226 is defined as the number of participants found to have seroconverted or boosted their pre-existing ADA during the study period. Baseline ADA positive is defined as ADA is detected in the last sample before initiation of treatment. ADA positive is defined as 1) an ADA detected (positive seroconversion) sample in a participant for whom ADA is not detected at baseline, or (2) an ADA detected sample with ADA titer to be at least 4-fold or greater (≥) than baseline positive titer.

All treated participants with baseline and at lease one post-baseline assessment

Summary measures of changes in Median of Fluorescence of ICOS (MFI) from baseline to the last evaluable time point in cell surface Inducible Costimulator (ICOS) expression on T cells. Baseline = last non missing value prior or on to the first dosing. MFI is a unit for median fluorescence intensity. This unit allows for measurement of relative expression of cell surface markers by a flow cytometer. For the ICOS expression assay, whole blood samples collected from patients on study were incubated with fluorescently labeled antibodies that specifically bind to ICOS. Samples were then analyzed for changes in MFI by flow cytometry. An increase in MFI between patient samples corresponds to an increase in cell surface ICOS expression on target cell subsets.

Biomarker Evaluable Participants: All treated participants with available biomarker data

Summary measures of changes in Median of Fluorescence of ICOS (MFI) from baseline to the last evaluable time point in ICOS ligand+ B cells in the tumor and peripheral blood. Baseline = last non missing value prior or on to the first dosing. MFI is a unit for median fluorescence intensity. This unit allows for measurement of relative expression of cell surface markers by a flow cytometer. For the ICOS expression assay, whole blood samples collected from patients on study were incubated with fluorescently labeled antibodies that specifically bind to ICOS. Samples were then analyzed for changes in MFI by flow cytometry. An increase in MFI between patient samples corresponds to an increase in cell surface ICOS expression on target cell subsets.

Biomarker Evaluable Participants: All treated participants with available biomarker data

Cmax is the maximum serum concentration that a drug achieves after the drug has been administered and before the administration of a second dose.

Evaluable PK Population: All treated participants who have evaluable serum concentration-time data

Effective elimination half-life that explains the degree of accumulation observed

Evaluable PK Population: All treated participants who have evaluable serum concentration-time data

Trough observed serum concentrations (Ctrough) is defined as the concentration reached by a drug immediately before the next dose is administered

Evaluable PK Population: All treated participants who have evaluable serum concentration-time data

Tmax is defined as the amount of time that a drug is present at the maximum concentration in serum

Evaluable PK Population: All treated participants who have evaluable serum concentration-time data

AUC(0-t) (partial AUC) is defined as the area under the concentration-time curve from dosing (time 0) to time t. AUC(0-t) may be computed for one or more values of t, with specific values of t determined after observing the data.

Evaluable PK Population: All treated participants who have evaluable serum concentration-time data

AUC (TAU) is defined as the area under the plasma concentration-time curve from time zero to the end of the dosing interval

Evaluable PK Population: All treated participants who have evaluable serum concentration-time data

CLT is defined as the elimination of the drug from the body

Evaluable PK Population: All treated participants who have evaluable serum concentration-time data

Css-avg is defined as the average concentration over a dosing interval (AUC[TAU]/tau)

Note: Coefficient of variation is reported in lieu of geometric coefficient of variation

Evaluable PK Population: All treated participants who have evaluable serum concentration-time data

Accumulation Index is defined as the extent of drug accumulation and determined by the ratio of plasma concentration at plateau over plasma concentration after the first dose. The area under curve is defined as the area under the plot of plasma concentration of a drug versus time after dosage which reflects the extent of exposure to a drug and its clearance rate from the body.

Evaluable PK Population: All treated participants who have evaluable serum concentration-time data

Accumulation Index is defined as the extent of drug accumulation and determined by the ratio of plasma concentration at plateau over plasma concentration after the first dose. Cmax is the maximum serum concentration that a drug achieves after the drug has been administered and before the administration of a second dose.

Evaluable PK Population: All treated participants who have evaluable serum concentration-time data

Accumulation Index is defined as the extent of drug accumulation and determined by the ratio of plasma concentration at plateau over plasma concentration after the first dose.

Evaluable PK Population: All treated participants who have evaluable serum concentration-time data