SUMMARY OF KEY CHANGES FOR REVISED PROTOCOL 03 Section Number & Title Description of Change Brief Rationale Section 3 Introduction Section 3.2.1: Indication Background Table 5.1-1: Study Cohorts per Part Section 5.1.2.4: Combination Expansion Arms (Parts D and E) Section 6.1: Inclusion Criteria Appendix 1: Abbreviations and TrademarksNew tumor types were added and discussed: cervical cancer (CC), melanoma (MEL), renal cell carcinoma (RCC), and triple negative breast cancer (TNBC). Up to three courses of prior systemic therapy are permitted in HNSCC, NSCLC, PRC and UCC tumor types, which has been changed from two prior courses.Modifications were made to expand the study population to include additional disease types and patient cohorts that could potentially derive benefit from ICOS agonist therapy, based on recently published literature. Table 2.1: Screening Procedural Outline. Section 6.1 Inclusion CriteriaFresh Pretreatment Tumor Biopsy procedures were modified as follows: The requirement for central assessment of tumor content and ICOS expression prior to Day 1 of study treatment administration (Cycle 1 Day 1) was removed. A requirement for pretreatment biopsy collection and shipment for analysis has been added.Modification was made to expedite the time-between enrollment and first treatment, as well as to reduce the potential risk of re-biopsy for participants who had recently undergone the procedure for confirmation of disease progression. Revised Protocol No.: 04 Date: 31-May-2019 229 Approved 5.0 v Approved 1.0 v Clinical Protocol CA021002 BMS-986226 anti-ICOS SUMMARY OF KEY CHANGES FOR REVISED PROTOCOL 03 Section Number & Title Description of Change Brief Rationale Table 2.1: Screening Procedural Outline Section 5.1.1: ScreeningTiming for tetanus booster administration between Days -7 to -3, prior to dosing was added.The timing of tetanus booster administration was narrowed in order to synchronize the antigen specific immune response within each treatment cohort. Section 2.2: On-treatment Procedural OutlineChemistry and CBC with Differential and Platelets were added to list of laboratory tests performed on Cycle 2 Day 2 and Cycle 2 Day 8. Additionally, all laboratory tests were specified to be performed on Day 1 of each cycle.Modification was made to improve clinical monitoring of hematologic and metabolic effects of BMS-986226 therapy. Pharmacokinetic and Immunogenicity Tables 9.5-1 through Table 9.5-4Sampling time points were adjusted and/or tables removed The tables in this section were modified to support more robust assessment for PK and immunogenicity while aligning with clinical assessment. Table 2-4: Additional Treatment Procedural Outline (Former Table 2-4: Retreatment Day 0 Procedural Outline) Table 2-5: Additional Treatment Follow-up Procedural Outline (Former Table 2-5: Retreatment and Extended Treatment Procedural Outline) Former Table 2-6: Retreatment and Extended Treatment Follow- up Procedural Outline Section 5.1.5.1: Retreatment During Response Follow-upRetreatment was removed as an option for patients who have relapsed after experiencing CR/PR or SD after completing study treatment. All tables and text referring to retreatment were removed from the protocol.The option for retreatment of participants on the study was removed from the protocol as there is minimal evidence to support retreatment of participants who have progressed after completing a course of experimental therapy. Revised Protocol No.: 04 Date: 31-May-2019 230 Approved 5.0 v Approved 1.0 v Clinical Protocol CA021002 BMS-986226 anti-ICOS SUMMARY OF KEY CHANGES FOR REVISED PROTOCOL 03 Section Number & Title Description of Change Brief Rationale Appendix 3: Adverse Events and Serious Adverse Events: definitions and procedures for recording, evaluating, follow up and reportingThe previous version of Appendix 3 was replaced. The Appendix was replaced to align with latest BMS standards. Section 1 Synopsis Section 5.1 Section 10.1.1 Appendix 10 Clarifications made to the language describing the application of BLRM/BLRM-Copula. Reference to BLRM-RD removed from protocol.Language referencing the BLRM model was adjusted in order to clarify starting dose decision algorithms for the combination cohorts as well as more precisely defining the application of BLRM/BLRM- Copula in dose escalation assessments. Section 3.2.2.4: Clinical Pharmacology and Safety. Section 3.2.2.5: Pharmacokinetics of BMS-986226Sections were updated to describe results from dosing of 12 participants to date.Information was updated to provide latest data available on the safety of BMS-986226 in human subjects. AllMinor formatting and typographical corrections.Made corrections for clarity and consistency within the document. Overall Rationale for the Revised Protocol 02, 03-Apr-2018 This protocol has been revised to modify the combination escalation of BMS-986226 with either nivolumab (Part B) or ipilimumab (Part C) to include and prioritize a Q12W dosing schedule that will provide pharmacodynamic data to inform dose and schedule. To rapidly inform a combination dose and schedule, the protocol was modified to allow Parts B and C to accrue while Part A is still open. In addition, on-treatment biopsy co llections were changed to the 2W and 12W timepoints to more accurately capture pharmacodynamic activity and a tetanus booster w ill be administered to capture pharmacodynamic activity in an antigen-specific context. Finally, tr eatment duration of BMS-986226 in combination with nivolumab or ipilimumab will be 2 years, rather than 24 weeks, to align with published data on the efficacy of treatment with nivolumab monotherapy for 2 years. Sections in the synopsis have been updated to align with the protocol section changes listed below.