COVID-19 Study Assessing the Efficacy and Safety of Anti-Spike SARS CoV-2 Monoclonal Antibodies for Prevention of SARS CoV-2 Infection Asymptomatic in Healthy Adults and Adolescents Who Are Household Contacts to an Individual With a Positive SARS-CoV-2 RT-PCR Assay

Healthy Participants Clinical Trial

Official title:

A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study Assessing the Efficacy and Safety of Anti-Spike SARS-CoV-2 Monoclonal Antibodies in Preventing SARS-CoV-2 Infection in Household Contacts of Individuals Infected With SARS-CoV-2

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04452318
• Other study ID #: R10933-10987-COV-2069
• Secondary ID: 2020-003654-71
• Status: Completed
• Phase: Phase 3
• Start date: July 13, 2020
• Est. completion date: October 4, 2021

Study information

• Verified date: April 2023
• Source: Regeneron Pharmaceuticals
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Primary Objectives:

Cohort A:

• To evaluate the efficacy of REGN10933+REGN10987 compared to placebo in preventing symptomatic SARS-CoV-2 infection (broad-term) confirmed by RT-qPCR

Cohort A and Cohort A1:

• To evaluate the safety and tolerability of REGN10933+REGN10987 following subcutaneous (SC) administration compared to placebo

Cohort B • To evaluate the efficacy of REGN10933+REGN10987 compared to placebo in preventing COVID-19 symptoms (broad-term)

Cohort B and Cohort B1

• To evaluate the safety and tolerability of REGN10933+REGN10987 following SC administration compared to placebo

Description:

Cohort A: adult and adolescent subjects (≥12 years) who are SARS -CoV-2 RT-qPCR negative at baseline

Cohort A1: pediatric subjects (<12 years) who are SARS-CoV-2 RT--qPCR negative at baseline

Cohort B: adult and adolescent subjects (≥12 years) who are SARS -CoV-2 RT-qPCR positive at baseline

Cohort B1: pediatric subjects (<12 years) who are SARS-CoV-2 RT--qPCR positive at baseline

Recruitment information / eligibility

• Status: Completed
• Enrollment: 3303
• Est. completion date: October 4, 2021
• Est. primary completion date: October 4, 2021
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 1 Day and older

Eligibility

Key Inclusion Criteria:

1. Adult subjects 18 years of age (irrespective of weight) and above at the signing of informed consent or adolescent participants =12 to <18 years of age, or pediatric participants <12 years of age at the signing of the assent (parent/guardian sign the informed consent)

2. Asymptomatic household contact with exposure to an individual with a diagnosis of SARS-CoV-2 infection (index case). To be included in the study, participants must be randomized within 96 hours of collection of the index cases' positive SARS-COV-2 diagnostic test sample

3. Participant anticipates living in the same household with the index case until study day 29

4. Is judged by the investigator to be in good health based on medical history and physical examination at screening/baseline, including participants who are healthy or have a chronic, stable medical condition

5. Willing and able to comply with study visits and study-related procedures/assessments.

6. Provide informed consent signed by study participant or legally acceptable representative.

Key Exclusion Criteria:

1. History of prior positive SARS-CoV-2 RT-PCR test or positive SARS-CoV-2 serology test at any time before the screening

2. Participant has lived with individuals who have had previous SARS-CoV-2 infection or currently lives with individuals who have SARS-CoV-2 infection, with the exception of the index case(s), the first individual(s) known to be infected in the household

3. Active respiratory or non-respiratory symptoms consistent with COVID-19

4. History of respiratory illness with sign/symptoms of SARS-CoV-2 infection, in the opinion of the investigator, within the prior 6 months to screening

5. Nursing home resident

6. Any physical examination findings, and/or history of any illness, concomitant medications or recent live vaccines that, in the opinion of the study investigator, might confound the results of the study or pose an additional risk to the participant by their participation in the study

Note: Other protocol-defined Inclusion/ Exclusion criteria apply

Related Conditions & MeSH terms

• COVID-19
• Healthy Participants

Intervention

Drug:
• REGN10933 + REGN10987
Subcutaneous (SC) or Intramuscular (IM) injections
• Placebo
SC or IM injections

Locations

Country	Name	City	State
Moldova, Republic of	Regeneron Study Site	Chisinau
Romania	Regeneron Study Site	Bucharest
United States	Regeneron Study Site	Ames	Iowa
United States	Regeneron Study Site	Atlanta	Georgia
United States	Regeneron Study Site	Atlanta	Georgia
United States	Regeneron Study Site	Aurora	Colorado
United States	Regeneron Study Site	Baltimore	Maryland
United States	Regeneron Study Site	Bellaire	Texas
United States	Regeneron Study Site	Boca Raton	Florida
United States	Regeneron Study Site	Boston	Massachusetts
United States	Regeneron Study Site	Boston	Massachusetts
United States	Regeneron Study Site	Boston	Massachusetts
United States	Regeneron Study Site	Boston	Massachusetts
United States	Regeneron Study Site	Boston	Massachusetts
United States	Regeneron Study Site	Bronx	New York
United States	Regeneron Study Site 1	Bronx	New York
United States	Regeneron Study Site 2	Bronx	New York
United States	Regeneron Study Site	Buffalo	New York
United States	Regeneron Study Site	Chapel Hill	North Carolina
United States	Regeneron Study Site	Charleston	South Carolina
United States	Regeneron Study Site	Charleston	South Carolina
United States	Regeneron Study Site	Charlotte	North Carolina
United States	Regeneron Study Site	Charlottesville	Virginia
United States	Regeneron Study Site	Chattanooga	Tennessee
United States	Regeneron Study Site	Chicago	Illinois
United States	Regeneron Study Site	Chicago	Illinois
United States	Regeneron Study Site 2	Chicago	Illinois
United States	Regeneron Study Site 3	Chicago	Illinois
United States	Regeneron Study Site	Cincinnati	Ohio
United States	Regeneron Study Site	Clearwater	Florida
United States	Regeneron Study Site	Clinton	South Carolina
United States	Regeneron Study Site	Colorado Springs	Colorado
United States	Regeneron Study Site	Columbus	Georgia
United States	Regeneron Study Site	Columbus	Ohio
United States	Regeneron Study Site	Columbus	Ohio
United States	Regeneron Study Site	Corpus Christi	Texas
United States	Regeneron Study Site	Dallas	Texas
United States	Regeneron Study Site	Danville	Pennsylvania
United States	Regeneron Study Site	Dayton	Ohio
United States	Regeneron Study Site	Decatur	Georgia
United States	Regeneron Study Site	DeLand	Florida
United States	Regeneron Study Site	Detroit	Michigan
United States	Regeneron Study Site 1	Downers Grove	Illinois
United States	Regeneron Study Site 2	Downers Grove	Illinois
United States	Regeneron Study Site	Eatonton	Georgia
United States	Regeneron Study Site	Everett	Washington
United States	Regeneron Study Site	Fayetteville	North Carolina
United States	Regeneron Study Site	Fort Pierce	Florida
United States	Regeneron Study Site	Gaffney	South Carolina
United States	Regeneron Study Site	Gulfport	Mississippi
United States	Regeneron Study Site	Hazelwood	Missouri
United States	Regeneron Study Site	Hialeah	Florida
United States	Regeneron Study Site	Houston	Texas
United States	Regeneron Study Site	Houston	Texas
United States	Regeneron Study Site	Houston	Texas
United States	Regeneron Study Site	Houston	Texas
United States	Regeneron Study Site	Houston	Texas
United States	Regeneron Study Site	Jackson	Mississippi
United States	Regeneron Study Site	Jacksonville	Florida
United States	Regeneron Study Site	Knoxville	Tennessee
United States	Regeneron Study Site	La Mesa	California
United States	Regeneron Study Site	La Palma	California
United States	Regeneron Study Site	Lake Charles	Louisiana
United States	Regeneron Study Site	Lakeland	Florida
United States	Regeneron Study Site	Las Vegas	Nevada
United States	Regeneron Study Site	Las Vegas	Nevada
United States	Regeneron Study Site	Long Beach	California
United States	Regeneron Study Site	Los Angeles	California
United States	Regeneron Study Site	Los Angeles	California
United States	Regeneron Study Site	Los Angeles	California
United States	Regeneron Study Site	Loxahatchee Groves	Florida
United States	Regeneron Study Site	Madison	Wisconsin
United States	Regeneron Study Site	Maitland	Florida
United States	Regeneron Study Site	Marietta	Georgia
United States	Regeneron Study Site	Marrero	Louisiana
United States	Regeneron Study Site	Memphis	Tennessee
United States	Regeneron Study Site	Mesa	Arizona
United States	Regeneron Study Site	Metairie	Louisiana
United States	Regeneron Study Site	Miami	Florida
United States	Regeneron Study Site	Miami	Florida
United States	Regeneron Study Site	Miami	Florida
United States	Regeneron Study Site	Miami	Florida
United States	Regeneron Study Site	Miami	Florida
United States	Regeneron Study Site	Miami	Florida
United States	Regeneron Study Site	Miami	Florida
United States	Regeneron Study Site	Minneapolis	Minnesota
United States	Regeneron Study Site	Montclair	California
United States	Regeneron Study Site	Morristown	New Jersey
United States	Regeneron Study Site	Nashville	Tennessee
United States	Regeneron Study Site	New Orleans	Louisiana
United States	Regeneron Study Site	New York	New York
United States	Regeneron Study Site	New York	New York
United States	Regeneron Study Site	New York	New York
United States	Regeneron Study Site	New York	New York
United States	Regeneron Study Site	New York	New York
United States	Regeneron Study Site	New York	New York
United States	Regeneron Study Site	Newark	New Jersey
United States	Regeneron Study Site	Northridge	California
United States	Regeneron Study Site	Orlando	Florida
United States	Regeneron Study Site	Oxnard	California
United States	Regeneron Study Site	Pearland	Texas
United States	Regeneron Study Site	Philadelphia	Pennsylvania
United States	Regeneron Study Site	Philadelphia	Pennsylvania
United States	Regeneron Study Site	Providence	Rhode Island
United States	Regeneron Study Site	Raleigh	North Carolina
United States	Regeneron Study Site	Red Oak	Texas
United States	Regeneron Study Site	Richmond	Virginia
United States	Regeneron Study Site	Royal Oak	Michigan
United States	Regeneron Study Site	Sacramento	California
United States	Regeneron Study Site	Sacramento	California
United States	Regeneron Study Site	Saint Louis	Missouri
United States	Regeneron Study Site	San Antonio	Texas
United States	Regeneron Study Site	San Diego	California
United States	Regeneron Study Site	San Francisco	California
United States	Regeneron Study Site	Sandy Springs	Georgia
United States	Regeneron Study Site	Sarasota	Florida
United States	Regeneron Study Site	Seattle	Washington
United States	Regeneron Study Site	Sioux Falls	South Dakota
United States	Regeneron Study Site	Stanford	California
United States	Regeneron Study Site	Summit	New Jersey
United States	Regeneron Study Site	Tampa	Florida
United States	Regeneron Study Site	Teaneck	New Jersey
United States	Regeneron Study Site	Torrance	California
United States	Regeneron Study Site	Torrance	California
United States	Regeneron Study Site	Tucson	Arizona
United States	Regeneron Study Site	Tucson	Arizona
United States	Regeneron Study Site	Tyler	Texas
United States	Regeneron Study Site	Washington	District of Columbia
United States	Regeneron Study Site	West Palm Beach	Florida
United States	Regeneron Study Site	Wilkes-Barre	Pennsylvania
United States	Regeneron Study Site	Wilmington	North Carolina
United States	Regeneron Study Site	Winston-Salem	North Carolina
United States	Regeneron Study Site	Winter Park	Florida
United States	Regeneron Study Site	Yakima	Washington

Sponsors (1)

Lead Sponsor	Collaborator
Regeneron Pharmaceuticals

Countries where clinical trial is conducted

United States,  Moldova, Republic of,  Romania, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Cohort A: Percentage of Participants Who Have a Symptomatic RT-qPCR Confirmed SARS-CoV-2 Infection (Broad-term) During the EAP	Symptomatic SARS-CoV-2 infection (broad-term) is defined as a positive central lab SARS-CoV-2 RT-qPCR result (either NP, nasal or saliva) associated with signs and symptoms with the onset date occurring within 14 days of a positive RT-qPCR during the EAP. Percentage estimated by Logistic Regression.	Up to 1 month
Primary	Cohort B: Percentage of Participants Who Subsequently Develop Signs and Symptoms (Broad-Term) Within 14 Days of a Positive RT-qPCR at Baseline or During the EAP	The percentage of participants was estimated by using the logistic regression model with fixed categorical effects of treatment group, age group (age in years:>=12 to=50), and region (US vs ex-US).	Up to 14 Days
Primary	Cohort A and Cohort B: Number of Participants With at Least One Treatment-emergent Adverse Event (TEAEs) and Severity of TEAEs		Up to 8 months
Secondary	Cohort A and Cohort B: Percentage of Participants With High Viral Load in Nasopharyngeal (NP) Swab Samples During the EAP	High viral load (> 4 log 10 copies/ml)	Up to 1 month
Secondary	Cohort A: Number of Weeks of Symptomatic RT-qPCR Confirmed SARS-CoV-2 Infection (Broad Term) During the EAP		Up to 1 month
Secondary	Cohort A and Cohort B: Number of Weeks of High Viral Load in NP Swab Samples During the EAP	High viral load (> 4 log 10 copies/ml)	Up to 1 month
Secondary	Cohort A: Number of Weeks of RT-qPCR Confirmed SARS-CoV-2 Infection (Regardless of Symptoms) During the EAP		Up to 1 month
Secondary	Cohort A: Percentage of Participants Who Have a RT-qPCR Confirmed SARS-CoV-2 Infection (Regardless of Symptoms) During the EAP	The percentage of participants was estimated by using the logistic regression model with fixed categorical effects of treatment group, age group (age in years:>=12 to=50), and region (US vs ex-US)	Up to 1 month
Secondary	Cohort A: Percentage of Participants in Placebo Group With a RT-qPCR Confirmed SARS-CoV-2 Infection During the EAP With an Index Case Participating in Study R10933-10987-COV-2067 (NCT04425629)		Up to 1 month
Secondary	Cohort A: Percentage of Participants With a Symptomatic RT-qPCR Confirmed SARS-CoV-2 Infection (CDC Definition) During the EAP	Symptomatic SARS-CoV-2 infection (CDC definition) is defined as a positive central lab SARS-CoV-2 RT-qPCR result (either NP, nasal or saliva) associated with signs and symptoms with the onset date occurring within 14 days of a positive RT-qPCR during the EAP. Percentage estimated by Logistic Regression.	Up to 1 month
Secondary	Cohort A: Number of Weeks of Symptomatic RT-qPCR-confirmed SARS-CoV-2 Infection (CDC Definition) During the EAP		Up to 1 month
Secondary	Cohort A: Percentage of Participants Who Have a Symptomatic RT-qPCR Confirmed SARS-CoV-2 Infection (Strict-term) During the EAP	The percentage of participants was estimated by using the logistic regression model with fixed categorical effects of treatment group, age group (age in years:>=12 to=50), and region (US vs ex-US)	Up to 1 month
Secondary	Cohort A: Number of Weeks of Symptomatic RT-qPCR Confirmed SARS-CoV-2 Infection (Strict-term) During the EAP		Up to 1 month
Secondary	Cohort A: Percentage of Participants Who Have a RT-qPCR Confirmed SARS-CoV-2 Infections at Each Week in the EAP		Week 1, Week 2, Week 3, Week 4
Secondary	Cohort A: Percentage of Participants Who Have a Symptomatic RT-qPCR Confirmed SARS-CoV-2 Infection (Broad-term) at Each Week in the EAP	The percentage of participants was estimated by using the logistic regression model with fixed categorical effects of treatment group, age group (age in years:>=12 to=50), and region (US vs ex-US)	Week 1, Week 2, Week 3, Week 4
Secondary	Cohort A: Time-weighted Average of Viral Load From the First Positive SARS CoV-2 RT-qPCR in NP Swab Samples (That Has an Onset During the EAP) Until the Third Weekly Visit After the First Positive Test During the EAP		Up to 1 month
Secondary	Cohort A: Time-weighted Average of Viral Load From the First Positive SARS-CoV-2 RT-qPCR in NP Swab Samples (That Has an Onset During the EAP) Until the Second Weekly Visit After the First Positive Test During the EAP		Up to 1 month
Secondary	Cohort A: Maximum SARS-CoV-2 RT-qPCR Viral Load in NP Swab Samples Among Individuals With =1 RT-qPCR Positive That Has an Onset During the EAP		Up to 1 month
Secondary	Cohort A: SARS-CoV-2 RT-qPCR Viral Load in NP Swab Samples Corresponding to the Onset of First Positive RT-qPCR During the EAP		Up to 1 month
Secondary	Cohort A: Area Under the Curve (AUC) in Viral Load From the First Positive SARS-CoV-2 RT-qPCR NP Swab Samples Detected During the EAP Until the First Confirmed Negative Test		Up to 1 month
Secondary	Cohort A: Total Number of Medically Attended Visits in Emergency Rooms or Urgent Care Centers Related to a RT-qPCR Confirmed SARS-CoV-2 Infection That Has an Onset During the EAP	Medically attended visits referred to hospitalizations, Emergency Room visits, or visits at an Urgent Care center.	Up to 1 month
Secondary	Cohort A: Percentage of Participants With at Least 1 COVID-19-related Hospitalization or Emergency Room Visit Associated With a Positive RT-qPCR During the EAP or All-cause Death		Up to 1 month
Secondary	Cohort A: Percentage of Participants Requiring Medically Attended Visits in Emergency Rooms or Urgent Care Centers Related to a RT-qPCR Confirmed SARS CoV-2 Infection That Has an Onset During the EAP		Up to 1 month
Secondary	Cohort A: Proportion of Participants Hospitalized Related to a RT-qPCR Confirmed SARS-CoV-2 Infection That Has an Onset During the EAP	The proportion of participants hospitalized related to a RT-qPCR confirmed SARS-CoV-2 infection that has an onset during the EAP	Up to 14 Days
Secondary	Cohort A: Number of Days of Hospital and Intensive Care Unit (ICU) Stay in Participants Hospitalized for a RT-qPCR Confirmed SARS-CoV-2 Infection That Has an Onset During the EAP		Up to Day 29
Secondary	Cohort A: Number of Days Missed for Daily Responsibilities Due to a RT-qPCR Confirmed SARS-CoV-2 Infection That Has an Onset During the EAP	Daily responsibilities including work (employed adults) or school (students), daycare or family obligations/responsibilities (childcare or eldercare)	Up to 1 month
Secondary	Cohort A: Proportion of Baseline Seropositive Participants (Based on Central Lab Test) With TEAEs and Severity of TEAEs		Up to 8 months
Secondary	Cohort A and Cohort B: Incidence and Severity of Symptomatic SARS-CoV-2 Infections During the EAP		Up to Day 29
Secondary	Cohort A and Cohort B: Incidence and Severity of Symptomatic SARS-CoV-2 Infections During the Follow-Up Period		Day 30 Up to Day 225 (Approximately 8 months)
Secondary	Cohort A and Cohort B: Incidence and Severity of Symptomatic SARS-CoV-2 Infections in Seronegative Subjects During the EAP		Up to Day 29
Secondary	Cohort A and Cohort B: Incidence and Severity of Symptomatic SARS-CoV-2 Infections in Seronegative Subjects During the Follow-Up Period		Day 30 Up to Day 225 (Approximately 8 months)
Secondary	Cohort A and Cohort B: Incidence and Severity of Symptomatic SARS-CoV-2 Infections in Seropositive Subjects During the EAP		Up to Day 29
Secondary	Cohort A and Cohort B: Incidence and Severity of Symptomatic SARS-CoV-2 Infections in Seropositive Subjects During the Follow-Up Period		Day 30 Up to Day 225 (Approximately 8 months)
Secondary	Cohort B: Number of Weeks of Symptomatic SARS-CoV-2 Infection (Broad-term) Within 14 Days of a Positive RT-qPCR at Baseline or During the EAP		Up to 14 Days
Secondary	Cohort B: Percentage of Participants With Asymptomatic Infection Who Develop Signs and Symptoms (CDC Definition) Within 14 Days of a Positive RT-qPCR at Baseline or During the EAP	The percentage of participants was estimated by using the logistic regression model with fixed categorical effects of treatment group, age group (age in years:>=12 to=50), and region (US vs ex-US)	Up to 1 month
Secondary	Cohort B: Percentage of Participants Who Subsequently Develop Signs and Symptoms (Strict-term) Within 14 Days of a Positive RT-qPCR at Baseline or During the EAP	The percentage of participants was estimated by using the logistic regression model with fixed categorical effects of treatment group, age group (age in years:>=12 to=50), and region (US vs ex-US)	Up to 14 Days
Secondary	Cohort B: Number of Weeks of Symptomatic SARS-CoV-2 Infection (CDC Definition) Within 14 Days of a Positive RT-qPCR at Baseline or During the EAP		Up to 14 Days
Secondary	Cohort B: Number of Weeks of Symptomatic SARS-CoV-2 Infection (Strict-term Definition) Within 14 Days of a Positive RT-qPCR at Baseline or During the EAP		Up to 14 Days
Secondary	Cohort B: Change in Viral Load From Baseline to Day 8 Visit in NP Swab Samples		Up to day 8 visit
Secondary	Cohort B: Change in Viral Load From Baseline to Day 15 Visit in NP Swab Samples		Up to day 15 visit
Secondary	Cohort B: Time-weighted Average Change From Baseline in Viral Load (log10 Copies/mL) in NP Swab Samples Until the Day 22 Visit		Day 22
Secondary	Cohort B: AUC in Viral Load From the First Positive SARS-CoV-2 RT-qPCR NP Swab Samples Detected During the EAP to the First Confirmed Negative Test		Up to 14 Days
Secondary	Cohort B: Maximum SARS-CoV-2 RT-qPCR Viral Load in NP Swab Samples in Participants With 1 or More Positive Test That Has an Onset During the EAP		Up to 1 month
Secondary	Cohort B: Number of Medically Attended Visits in Emergency Rooms or Urgent Care Centers Related to RT-qPCR Confirmed SARS-CoV-2 Infection That Has an Onset at Baseline or During the EAP		Up to 1 month
Secondary	Cohort B: Percentage of Participants Requiring Medically Attended Visits in Emergency Rooms or Urgent Care Centers Related to a RT-qPCR Confirmed SARS CoV-2 Infection That Has an Onset at Baseline or During the EAP		Up to 1 month
Secondary	Cohort B: Percentage of Participants Hospitalized Related to a RT-qPCR Confirmed SARS-CoV-2 Infection That Has an Onset at Baseline or During the EAP		Up to 14 Days
Secondary	Cohort B: Number of Days Missed for Daily Responsibilities (Where Applicable) Due to a RT-qPCR Confirmed SARS-CoV-2 Infection That Has an Onset at Baseline or During the EAP		Up to 1 month
Secondary	Cohort B: Number of Days of Hospital and Intensive Care Unit (ICU) Stay in Participants Hospitalized for a RT-qPCR Confirmed SARS-CoV-2 Infection That Has an Onset at Baseline or During the EAP		Up to 1 month
Secondary	Concentrations of REGN10987 in Serum Over Time (Cohort A)		0 Days Post-Dose, 28 Days Post-Dose, 56 Days Post-Dose, 112 Days Post-Dose
Secondary	Concentrations of REGN10987 in Serum Over Time (Cohort B)		0 Days Post-Dose, 28 Days Post-Dose, 56 Days Post-Dose, 112 Days Post-Dose
Secondary	Concentrations of REGN10933 in Serum Over Time (Cohort A)		0 Days Post-Dose, 28 Days Post-Dose, 56 Days Post-Dose, 112 Days Post-Dose
Secondary	Concentrations of REGN10933 in Serum Over Time (Cohort B)		0 Days Post-Dose, 28 Days Post-Dose, 56 Days Post-Dose, 112 Days Post-Dose
Secondary	Immunogenicity as Measured by Anti-drug Antibodies (ADAs) to REGN10933		Up to 8 months
Secondary	Immunogenicity as Measured by Anti-drug Antibodies (ADAs) to REGN10987		Up to 8 months
Secondary	Immunogenicity as Measured by Neutralizing Anti-drug Antibody (NAb) to REGN10933	(TE&TB+;NAb+) = TE = Treatment-Emergent; TB = Treatment-boosted; NAb+ = Positive in NAb assay	Up to 8 months
Secondary	Immunogenicity as Measured by Neutralizing Anti-drug Antibody (NAb) to REGN10987	(TE&TB+;NAb+) = TE = Treatment-emergent; TB = Treatment-boosted; NAb+ = Positive in NAb assay	Up to 8 Months