Janssen Vaccines & Prevention B.V.* Clinical Protocol Protocol Title A Randomized, Double-blind, Placebo-controlled Phase 3 Study to Assess the Efficacy and Safety of Ad26.COV2.S for the Prevention of SARS-CoV-2-mediated COVID-19 in Adults Aged 18 Years and Older ENSEMBLE Protocol VAC31518COV3001; Phase 3 AMENDMENT 3 VAC31518 (JNJ-78436735) * Janssen Vaccines & Prevention B.V. is a Janssen pharmaceutical company of Johnson & Johnson and is hereafter referred to as the sponsor of the study. The sponsor is identified on the Contact Information page that accompanies the protocol. United States (US) sites of this study will be conducted under US Food & Drug Administration Investigational New Drug (IND) regulations (21 CFR Part 312). Regulatory Agency Identifier Number: IND: 22657 Status: Approved Date: 14 December 2020 EDMS number: EDMS-RIM-50860, 6.0 GCP Compliance: This study will be conducted in compliance with Good Clinical Practice, and applicable regulatory requirements. 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CONFIDENTIAL – FOIA Exemptions Apply in U.S. 1 Status: Approved, Date: 14 December 2020 VAC31518 (JNJ-78436735) Clinical Protocol VAC31518COV3001 Amendment 3 PROTOCOL AMENDMENT SUMMARY OF CHANGES TABLE DOCUMENT HISTORY Document Date Amendment 3 This document Amendment 2 29 October 2020 Amendment 1 15 September 2020 Original Protocol 22 July 2020 Amendment 3 (This document) Overall Rationale for the Amendment: The main purpose of this amendment is to add first occurrence of molecularly confirmed, moderate to severe/critical COVID-19, with onset at least 28 days post-vaccination as a co-primary endpoint in addition to the current primary endpoint counting as of 14 days post-vaccination. The applicable secondary and exploratory endpoints were updated similarly to also include COVID-19 cases with onset at least 28 days post-vaccination. In addition, the total sample size was reduced from 60,000 to approximately 40,000 participants. The protocol is further amended to change the conditions for monitoring whether efficacy greater than 30% is achieved using the sequential monitoring algorithm: (1) The minimum number of COVID-19 cases meeting the primary case definition needed to start the efficacy monitoring was modified to at least 42 instead of 20, (2) The need for a follow-up of 8 weeks for 50% of the participants prior to an initial look at an efficacy signal if the other conditions are met was removed. These and other changes made to the clinical protocol of study VAC31518COV3001 are listed below, including the rationale of each change and a list of all applicable sections. Section Number Description of Change Brief Rationale and Name 1.1 Synopsis A co-primary endpoint was added This change will allow for formal 3 OBJECTIVES AND ENDPOINTS counting COVID-19 cases from testing and reporting of the 4.1 Overall Design 28 days post-vaccination (Day 29), primary endpoint counting cases 8.1.3.1 Case Definition for Moderate in addition to from 14 days post- from 28 days post-vaccination as to Severe/Critical COVID-19 vaccination (Day 15). an additional condition for 8.1.3.6 Clinical Severity success along with the 14 days The applicable secondary and Adjudication Committee post-vaccination endpoint results. exploratory endpoints were updated 9.1 Statistical Hypotheses Maintaining the original primary to also include COVID-19 cases 9.2.1 Efficacy (Total Sample Size) endpoint will preserve trial with onset at least 28 days post- 9.5.1 Primary Endpoints Evaluation integrity. This approach will vaccination, in addition to from 14 9.5.1.1 Study Monitoring allow to provide the most days post-vaccination. 9.5.2 Secondary Endpoints accurate description of the 9.8 Interim Analysis and Committees vaccine efficacy and to assess 10.3.6 Committees Structure vaccine efficacy as early as 14 days post-vaccination. 3 OBJECTIVES AND ENDPOINTS Deletion of the exploratory The Clinical Severity endpoint relating to evaluation of Adjudication Committee only the occurrence, severity and exists to determine severe/critical duration of COVID-19 episodes in cases of COVID-19. participants who received Ad26.COV2.S, as compared to placebo, by the Clinical Severity CONFIDENTIAL – FOIA Exemptions Apply in U.S. 2 Status: Approved, Date: 14 December 2020 VAC31518 (JNJ-78436735) Clinical Protocol VAC31518COV3001 Amendment 3 Section Number Description of Change Brief Rationale and Name Adjudication Committee, previously known as the Clinical Evaluation Committee. 9.2.1 Efficacy (Total Sample Size) The total sample size was reduced The incidence of moderate to 9.2.4 Safety (Safety Subset) from 60,000 to approximately severe COVID-19 seen in the US 40,000. and reported in other COVID-19 vaccine studies is significantly The paragraph on the operational higher than assumed at the time of futility was removed. protocol planning. Furthermore, based on that incidence and modeling, there is a high degree of probability that an efficacy signal meeting the prespecified criteria in this amendment will be reached at, or prior to, the time when 50% of participants will have been followed for 8 weeks from the time of vaccination. 1.1 Synopsis The conditions for monitoring (1) The minimum number of 9.5.1 Primary Endpoints Evaluation whether efficacy greater than 30% COVID-19 cases was increased to is achieved using the sequential have a more robust signal at the monitoring algorithm were time of the efficacy declaration. changed: (2) This change was made to (1) The minimum number of expedite submissions to ensure COVID-19 cases with onset at least the vaccine is made available to 28 days after vaccination meeting the public as soon as possible. the primary case definition needed Following 50% of participants for to start the efficacy monitoring was 8 weeks from the day of modified to at least 42 instead of vaccination meets the sponsor’s 20. understanding of the requirement (2) The need for a follow-up of for 8 weeks median follow-up for 8 weeks for 50% of participants a 40,000-participant study. prior to an initial look at an efficacy signal if the other conditions are met, was removed. In addition, text was added to clarify the timing of primary and interim analyses. 1.1 Synopsis A secondary objective and endpoint With the increased incidence of 3 OBJECTIVES AND ENDPOINTS were added assessing the efficacy disease that is being observed, the 9.5.2 Secondary Endpoints of the vaccine in the prevention of likelihood of having enough molecularly confirmed, severe cases of COVID-19 to severe/critical COVID-19 with examine vaccine efficacy against onset at least 14 days this endpoint has increased. post-vaccination and 28 days post- Vaccine efficacy against severe vaccination. disease is considered an important endpoint for a 1-dose vaccine. CONFIDENTIAL – FOIA Exemptions Apply in U.S. 3 Status: Approved, Date: 14 December 2020 VAC31518 (JNJ-78436735) Clinical Protocol VAC31518COV3001 Amendment 3 Section Number Description of Change Brief Rationale and Name 1.1 Synopsis An exploratory objective and This change allows the evaluation 1.3.1 All Participants endpoint were added assessing the of the effect of the vaccine on 3 OBJECTIVES AND ENDPOINTS effect of the vaccine on confirmed asymptomatic infections up to 8.1.3 Efficacy Assessments asymptomatic or undetected Day 29, in line with other efficacy 8.1.3.5 SARS-CoV-2 Seroconversion infections by testing serologic endpoints. Assessment conversion between baseline and 28 8.1.4 Immunogenicity Assessments days post-vaccination. 10.2 Appendix 2: Clinical Laboratory Tests 3 OBJECTIVES AND ENDPOINTS An exploratory objective and The vaccine will be especially endpoint to examine the degree of useful in the elderly population frailty were added. with co-morbidities. The frailty index has been utilized as a tool to summarize the degree of frailty that a participant has. 1.1 Synopsis The Clinical Evaluation Committee The standard case definition of 2.3.1 Risks Related to Study was replaced by the Clinical severe/critical disease may not Participation Severity Adjudication Committee. cover all situations where clinical 3 OBJECTIVES AND ENDPOINTS judgement would disagree with 8.1.3 Efficacy Assessments the classification on clinical 8.1.3.6 Clinical Severity grounds. Adjudication Committee 10.3.6 Committees Structure 1.1 Synopsis Addition of text defining the Clarification of the definitive role 8.1.3.1 Case Definition for Moderate definitive role of the Clinical of the Clinical Severity to Severe/Critical COVID-19 Severity Adjudication Committee Adjudication Committee in in determining whether cases are defining the severity of cases of severe/critical cases of COVID-19. COVID-19. 1.1 Synopsis Addition of the utilization of Participant medical data 1.3.1 All Participants tokenization and matching (electronic health records, claims, 3 OBJECTIVES AND ENDPOINTS procedures to obtain medical data laboratory data from other care 4.1 Overall Design 5 years prior to enrollment of the settings) prior to, during and 4.2 Scientific Rationale for Study participant until 5 years after the following participation in the Design participant completed the study study (real-world data) is 4.2.1 Study-Specific Ethical Design from consenting participants in the important to obtain in order to Considerations United States (US). better understand the impact of 8.8 Participant Medical Information prior medical history on the Prior to, During and After the Study response to immunization and the (Real-world Data) impact of immunization on 9.5.4 Other Analyses efficacy and duration of efficacy 10.1 Appendix 1: Abbreviations as well as adverse events that may 11 REFERENCES occur during and after completion of the study.