Trial Outcomes & Findings for Efficacy of the Anti-Bet v 1 Monoclonal Antibodies (Given Subcutaneously) to Reduce Allergic Rhinitis and Conjunctivitis Symptoms and Skin Test Reactivity Upon Exposure to Birch Allergen in Adult Participants (NCT NCT05430919)

NCT ID: NCT05430919

Last Updated: 2024-11-19

Results Overview

TNSS ranges from 0 (none) to 12 (severe): sum of 4 nasal symptoms (nasal congestion, itching, \& runny nose, \& sneezing) graded on a Likert scale ranging from 0 (none) to 3 (severe); Higher score indicates worse outcome.

• Recruitment status: COMPLETED
• Study phase: PHASE2
• Target enrollment: 217 participants
• Primary outcome timeframe: Day 29 from randomization (Out-of-season)
• Results posted on: 2024-11-19

Participant Flow

847 participants were screened, of which 217 were randomized

Participant milestones

Measure	Placebo Matching placebo	REGN5715 300 mg 1-monoclonal antibody (mAb) REGN5715 300 mg plus placebo to replace REGN5713-5714	REGN5713-5715 600 mg 2-monoclonal antibody (mAb) cocktail REGN5713-5715 600 mg (300 mg per mAb) plus placebo to replace REGN5714	REGN5713-5714-5715 900 mg 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)
Overall Study STARTED	55	55	52	55
Overall Study COMPLETED	52	54	51	54
Overall Study NOT COMPLETED	3	1	1	1

Reasons for withdrawal

Measure	Placebo Matching placebo	REGN5715 300 mg 1-monoclonal antibody (mAb) REGN5715 300 mg plus placebo to replace REGN5713-5714	REGN5713-5715 600 mg 2-monoclonal antibody (mAb) cocktail REGN5713-5715 600 mg (300 mg per mAb) plus placebo to replace REGN5714	REGN5713-5714-5715 900 mg 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)
Overall Study Protocol Violation	0	0	1	0
Overall Study Lost to Follow-up	0	1	0	0
Overall Study Withdrawal by Subject	3	0	0	1

Baseline Characteristics

Efficacy of the Anti-Bet v 1 Monoclonal Antibodies (Given Subcutaneously) to Reduce Allergic Rhinitis and Conjunctivitis Symptoms and Skin Test Reactivity Upon Exposure to Birch Allergen in Adult Participants

Baseline characteristics by cohort

Measure	Placebo n=55 Participants Matching placebo	REGN5715 300 mg n=55 Participants 1-monoclonal antibody (mAb) REGN5715 300 mg plus placebo to replace REGN5713-5714	REGN5713-5715 600 mg n=52 Participants 2-monoclonal antibody (mAb) cocktail REGN5713-5715 600 mg (300 mg per mAb) plus placebo to replace REGN5714	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Total n=217 Participants Total of all reporting groups
Age, Continuous	43.8 Years STANDARD_DEVIATION 13.72 • n=5 Participants	40.1 Years STANDARD_DEVIATION 11.15 • n=7 Participants	40.3 Years STANDARD_DEVIATION 10.87 • n=5 Participants	42.6 Years STANDARD_DEVIATION 12.56 • n=4 Participants	41.7 Years STANDARD_DEVIATION 12.17 • n=21 Participants
Sex: Female, Male Female	30 Participants n=5 Participants	27 Participants n=7 Participants	22 Participants n=5 Participants	34 Participants n=4 Participants	113 Participants n=21 Participants
Sex: Female, Male Male	25 Participants n=5 Participants	28 Participants n=7 Participants	30 Participants n=5 Participants	21 Participants n=4 Participants	104 Participants n=21 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	5 Participants n=5 Participants	5 Participants n=7 Participants	6 Participants n=5 Participants	5 Participants n=4 Participants	21 Participants n=21 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	49 Participants n=5 Participants	47 Participants n=7 Participants	46 Participants n=5 Participants	49 Participants n=4 Participants	191 Participants n=21 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	1 Participants n=5 Participants	3 Participants n=7 Participants	0 Participants n=5 Participants	1 Participants n=4 Participants	5 Participants n=21 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants	1 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	1 Participants n=21 Participants
Race (NIH/OMB) Asian	7 Participants n=5 Participants	6 Participants n=7 Participants	8 Participants n=5 Participants	12 Participants n=4 Participants	33 Participants n=21 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants	0 Participants n=21 Participants
Race (NIH/OMB) Black or African American	6 Participants n=5 Participants	5 Participants n=7 Participants	5 Participants n=5 Participants	5 Participants n=4 Participants	21 Participants n=21 Participants
Race (NIH/OMB) White	39 Participants n=5 Participants	43 Participants n=7 Participants	37 Participants n=5 Participants	36 Participants n=4 Participants	155 Participants n=21 Participants
Race (NIH/OMB) More than one race	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants	0 Participants n=4 Participants	2 Participants n=21 Participants
Race (NIH/OMB) Unknown or Not Reported	2 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants	2 Participants n=4 Participants	5 Participants n=21 Participants
Birch allergen EEU Mean Total Nasal Symptom Score (TNSS) (0 - 12) (2-6 Hours)	7.36 Scores on a Scale STANDARD_DEVIATION 2.489 • n=5 Participants	7.84 Scores on a Scale STANDARD_DEVIATION 2.479 • n=7 Participants	7.29 Scores on a Scale STANDARD_DEVIATION 2.414 • n=5 Participants	7.71 Scores on a Scale STANDARD_DEVIATION 2.549 • n=4 Participants	7.55 Scores on a Scale STANDARD_DEVIATION 2.477 • n=21 Participants

PRIMARY outcome

Timeframe: Day 29 from randomization (Out-of-season)

Population: Randomized participants in only the REGN5713-5714-5715 and placebo arms were assessed for this endpoint. Missing values were imputed using multiple imputation (MI) method.

TNSS ranges from 0 (none) to 12 (severe): sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on a Likert scale ranging from 0 (none) to 3 (severe); Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=55 Participants Matching placebo	Placebo Matching placebo	Placebo Matching placebo
Mean Total Nasal Symptom Score (TNSS) (2 to 6 Hours) During Out-of-season Birch Allergen Environmental Exposure Unit (EEU) Challenge (REGN5713-5714-5715 vs. Placebo) at Day 29	4.40 Scores on a Scale Standard Error 0.377	6.71 Scores on a Scale Standard Error 0.380	—	—

SECONDARY outcome

Timeframe: Day 29 from randomization (Out-of-season)

Population: Randomized participants in only the REGN5713-5715, REGN5715 and placebo arms were assessed for this endpoint. Missing values were imputed using multiple imputation (MI) method.

TNSS ranges from 0 (none) to 12 (severe): sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on a Likert scale ranging from 0 (none) to 3 (severe); Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=52 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo Matching placebo
Mean TNSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge (Except for REGN5713-5714-5715) at Day 29	4.06 Scores on a Scale Standard Error 0.406	5.20 Scores on a Scale Standard Error 0.393	6.71 Scores on a Scale Standard Error 0.380	—

SECONDARY outcome

Timeframe: Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

TNSS ranges from 0 (none) to 12 (severe): sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on a Likert scale ranging from 0 (none) to 3 (severe); Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Mean TNSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Day 57 and Day 85 Day 85	4.61 Scores on a Scale Standard Error 0.511	4.48 Scores on a Scale Standard Error 0.506	5.38 Scores on a Scale Standard Error 0.499	6.14 Scores on a Scale Standard Error 0.466
Mean TNSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Day 57 and Day 85 Day 57	4.47 Scores on a Scale Standard Error 0.458	3.89 Scores on a Scale Standard Error 0.471	5.58 Scores on a Scale Standard Error 0.451	6.29 Scores on a Scale Standard Error 0.445

SECONDARY outcome

Timeframe: Day 29 from randomization (Out-of-season)

Population: All randomized participants. Missing values were imputed using multiple imputation (MI) method.

TOSS ranges from 0 (none) to 6 (severe): sum of 2 eye symptoms graded on a Likert scale each ranging from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering; Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Mean Total Ocular Symptom Score (TOSS) (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Day 29	1.81 Scores on a Scale Standard Error 0.202	1.69 Scores on a Scale Standard Error 0.217	2.01 Scores on a Scale Standard Error 0.207	2.48 Scores on a Scale Standard Error 0.202

SECONDARY outcome

Timeframe: Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

TOSS ranges from 0 (none) to 6 (severe): sum of 2 eye symptoms graded on a Likert scale each ranging from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering; Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Mean TOSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Day 57 and Day 85 Day 85	1.90 Scores on a Scale Standard Error 0.243	1.96 Scores on a Scale Standard Error 0.241	1.91 Scores on a Scale Standard Error 0.238	2.51 Scores on a Scale Standard Error 0.223
Mean TOSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Day 57 and Day 85 Day 57	1.63 Scores on a Scale Standard Error 0.231	1.66 Scores on a Scale Standard Error 0.237	2.04 Scores on a Scale Standard Error 0.227	2.57 Scores on a Scale Standard Error 0.225

SECONDARY outcome

Timeframe: Day 29 from randomization (Out-of-season)

Population: All randomized participants. Missing values were imputed using multiple imputation (MI) method.

TSS ranges from 0 (none) to 18 (severe): sum of TNSS & TOSS combined; Higher score indicates worse outcome

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Mean Total Symptom Score (TSS) (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Day 29	6.22 Scores on a Scale Standard Error 0.549	5.76 Scores on a Scale Standard Error 0.592	7.21 Scores on a Scale Standard Error 0.572	9.20 Scores on a Scale Standard Error 0.553

SECONDARY outcome

Timeframe: Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

TSS ranges from 0 (none) to 18 (severe): sum of TNSS & TOSS combined; Higher score indicates worse outcome

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Mean TSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Day 57 and at Day 85 Day 57	6.09 Scores on a Scale Standard Error 0.652	5.57 Scores on a Scale Standard Error 0.671	7.62 Scores on a Scale Standard Error 0.642	8.86 Scores on a Scale Standard Error 0.634
Mean TSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Day 57 and at Day 85 Day 85	6.49 Scores on a Scale Standard Error 0.710	6.44 Scores on a Scale Standard Error 0.703	7.30 Scores on a Scale Standard Error 0.693	8.63 Scores on a Scale Standard Error 0.648

SECONDARY outcome

Timeframe: Day 29, Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

TNSS ranges from 0 (none) to 12 (severe): sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on a Likert scale ranging from 0 (none) to 3 (severe); Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Change From Pre-treatment Baseline in TNSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 29	-3.14 Scores on a Scale Standard Error 0.371	-3.52 Scores on a Scale Standard Error 0.411	-2.27 Scores on a Scale Standard Error 0.373	-0.84 Scores on a Scale Standard Error 0.376
Change From Pre-treatment Baseline in TNSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 57	-3.14 Scores on a Scale Standard Error 0.458	-3.71 Scores on a Scale Standard Error 0.471	-2.03 Scores on a Scale Standard Error 0.451	-1.31 Scores on a Scale Standard Error 0.445
Change From Pre-treatment Baseline in TNSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 85	-3.04 Scores on a Scale Standard Error 0.511	-3.17 Scores on a Scale Standard Error 0.506	-2.27 Scores on a Scale Standard Error 0.499	-1.50 Scores on a Scale Standard Error 0.466

SECONDARY outcome

Timeframe: Day 29, Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

TOSS ranges from 0 (none) to 6 (severe): sum of 2 eye symptoms graded on a Likert scale each ranging from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering; Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Change From Pre-treatment Baseline in TOSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 29	-1.11 Scores on a Scale Standard Error 0.202	-1.26 Scores on a Scale Standard Error 0.222	-0.87 Scores on a Scale Standard Error 0.202	-0.44 Scores on a Scale Standard Error 0.204
Change From Pre-treatment Baseline in TOSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 57	-1.41 Scores on a Scale Standard Error 0.231	-1.37 Scores on a Scale Standard Error 0.237	-100 Scores on a Scale Standard Error 0.227	-0.47 Scores on a Scale Standard Error 0.225
Change From Pre-treatment Baseline in TOSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 85	-1.15 Scores on a Scale Standard Error 0.243	-1.09 Scores on a Scale Standard Error 0.241	-1.14 Scores on a Scale Standard Error 0.238	-0.54 Scores on a Scale Standard Error 0.223

SECONDARY outcome

Timeframe: Day 29, Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

TSS ranges from 0 (none) to 18 (severe): sum of TNSS & TOSS combined; Higher score indicates worse outcome

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Change From Pre-treatment Baseline in TSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 29	-4.24 Scores on a Scale Standard Error 0.543	-4.76 Scores on a Scale Standard Error 0.600	-3.14 Scores on a Scale Standard Error 0.545	-1.26 Scores on a Scale Standard Error 0.550
Change From Pre-treatment Baseline in TSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 57	-4.55 Scores on a Scale Standard Error 0.652	-5.08 Scores on a Scale Standard Error 0.671	-3.02 Scores on a Scale Standard Error 0.642	-1.78 Scores on a Scale Standard Error 0.634
Change From Pre-treatment Baseline in TSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 85	-4.20 Scores on a Scale Standard Error 0.710	-4.26 Scores on a Scale Standard Error 0.703	-3.39 Scores on a Scale Standard Error 0.693	-2.06 Scores on a Scale Standard Error 0.648

SECONDARY outcome

Timeframe: Day 29, Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

TNSS ranges from 0 (none) to 12 (severe): sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on a Likert scale ranging from 0 (none) to 3 (severe); Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Percent Change From Pre-treatment Baseline in TNSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 29	-44.35 Percentage of Change Standard Error 5.099	-46.86 Percentage of Change Standard Error 5.645	-27.88 Percentage of Change Standard Error 5.132	-4.10 Percentage of Change Standard Error 5.173
Percent Change From Pre-treatment Baseline in TNSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 57	-42.98 Percentage of Change Standard Error 6.508	-48.26 Percentage of Change Standard Error 6.689	-29.48 Percentage of Change Standard Error 6.407	-11.65 Percentage of Change Standard Error 6.318
Percent Change From Pre-treatment Baseline in TNSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 85	-41.94 Percentage of Change Standard Error 7.683	-39.22 Percentage of Change Standard Error 7.607	-28.94 Percentage of Change Standard Error 7.505	-13.99 Percentage of Change Standard Error 7.003

SECONDARY outcome

Timeframe: Day 29, Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

TOSS ranges from 0 (none) to 6 (severe): sum of 2 eye symptoms graded on a Likert scale each ranging from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering; Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Percent Change From Pre-treatment Baseline in TOSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 29	-44.15 Percentage of Change Standard Error 7.729	-40.40 Percentage of Change Standard Error 8.504	-29.90 Percentage of Change Standard Error 7.731	-8.40 Percentage of Change Standard Error 7.807
Percent Change From Pre-treatment Baseline in TOSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 57	-53.08 Percentage of Change Standard Error 7.932	-44.70 Percentage of Change Standard Error 8.147	-35.02 Percentage of Change Standard Error 7.795	-11.64 Percentage of Change Standard Error 7.725
Percent Change From Pre-treatment Baseline in TOSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and 85 Day 85	-46.38 Percentage of Change Standard Error 9.206	-32.54 Percentage of Change Standard Error 9.117	-39.16 Percentage of Change Standard Error 8.997	-12.17 Percentage of Change Standard Error 8.431

SECONDARY outcome

Timeframe: Day 29, Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

TSS ranges from 0 (none) to 18 (severe): sum of TNSS & TOSS combined; Higher score indicates worse outcome

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Percent Change From Pre-treatment Baseline in TSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and Day 85 Day 29	-44.33 Percentage of Change Standard Error 5.274	-44.97 Percentage of Change Standard Error 5.830	-27.50 Percentage of Change Standard Error 5.298	-4.18 Percentage of Change Standard Error 5.347
Percent Change From Pre-treatment Baseline in TSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and Day 85 Day 57	-45.49 Percentage of Change Standard Error 6.283	-46.81 Percentage of Change Standard Error 6.460	-30.21 Percentage of Change Standard Error 6.182	-10.55 Percentage of Change Standard Error 6.110
Percent Change From Pre-treatment Baseline in TSS (2 to 6 Hours) During Out-of-season Birch Allergen EEU Challenge at Days 29, 57 and Day 85 Day 85	42.74 Percentage of Change Standard Error 7.252	-37.11 Percentage of Change Standard Error 7.186	-31.64 Percentage of Change Standard Error 7.084	-13.55 Percentage of Change Standard Error 6.621

SECONDARY outcome

Timeframe: Day 29 from randomization (Out-of-season)

Population: All randomized participants

Titrated skin prick test (SPT) AUC= The skin prick test mean wheal diameters [mm] using serial dilutions of the allergen were used to calculate an AUC. AUC of titrated SPT mean wheal diameters were derived using the trapezoidal rule. For each participant, the AUC was calculated for the mean wheal diameter calculated over titrated concentrations of the allergen on a log scale and then normalized.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Change From Pre-treatment Baseline in the Birch Titrated Skin Prick Test (SPT) Mean Wheal Diameter Area Under the Curve (AUC) at Day 29	-5.396 millimeter (mm) Standard Error 0.2822	-4.743 millimeter (mm) Standard Error 0.3243	-3.266 millimeter (mm) Standard Error 0.2983	-0.507 millimeter (mm) Standard Error 0.2946

SECONDARY outcome

Timeframe: Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

Titrated skin prick test (SPT) AUC= The skin prick test mean wheal diameters [mm] using serial dilutions of the allergen were used to calculate an AUC. AUC of titrated SPT mean wheal diameters were derived using the trapezoidal rule. For each participant, the AUC was calculated for the mean wheal diameter calculated over titrated concentrations of the allergen on a log scale and then normalized.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Change From Pre-treatment Baseline in the Birch Titrated SPT Mean Wheal Diameter AUC at Day 57 and Day 85 Day 57	-5.110 millimeter (mm) Standard Error 0.2878	-4.693 millimeter (mm) Standard Error 0.2976	-3.052 millimeter (mm) Standard Error 0.2837	-0.054 millimeter (mm) Standard Error 0.2789
Change From Pre-treatment Baseline in the Birch Titrated SPT Mean Wheal Diameter AUC at Day 57 and Day 85 Day 85	-4.418 millimeter (mm) Standard Error 0.3218	-4.241 millimeter (mm) Standard Error 0.3199	-1.757 millimeter (mm) Standard Error 0.3166	0.016 millimeter (mm) Standard Error 0.2930

SECONDARY outcome

Timeframe: Day 127 from randomization

Population: Randomized participants with Day 127 visit (intended to be pre-season) at least 12 weeks post-randomization

Titrated skin prick test (SPT) AUC= The skin prick test mean wheal diameters [mm] using serial dilutions of the allergen were used to calculate an AUC. AUC of titrated SPT mean wheal diameters were derived using the trapezoidal rule. For each participant, the AUC was calculated for the mean wheal diameter calculated over titrated concentrations of the allergen on a log scale and then normalized.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=28 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=26 Participants Matching placebo	Placebo n=31 Participants Matching placebo	Placebo n=31 Participants Matching placebo
Change From Pre-treatment Baseline in the Birch Titrated SPT Mean Wheal Diameter AUC at Day 127	-3.980 millimeter (mm) Standard Error 0.3673	-3.590 millimeter (mm) Standard Error 0.3907	-2.485 millimeter (mm) Standard Error 0.3539	0.058 millimeter (mm) Standard Error 0.3481

SECONDARY outcome

Timeframe: Day 225 from randomization (end-of-season) and Day 253 from randomization (end of study)

Population: Among randomized participants that received a second dose of study drug, the number of participants analyzed is the number of participants with a baseline measurement and post-baseline measurement. The number analyzed for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

Titrated skin prick test (SPT) AUC= The skin prick test mean wheal diameters [mm] using serial dilutions of the allergen were used to calculate an AUC. AUC of titrated SPT mean wheal diameters were derived using the trapezoidal rule. For each participant, the AUC was calculated for the mean wheal diameter calculated over titrated concentrations of the allergen on a log scale and then normalized.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=38 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=33 Participants Matching placebo	Placebo n=39 Participants Matching placebo	Placebo n=39 Participants Matching placebo
Change From Pre-treatment Baseline in the Birch Titrated SPT Mean Wheal Diameter AUC at Day 225 and Day 253 Day 225	-5.435 millimeter (mm) Standard Error 0.3648	-4.587 millimeter (mm) Standard Error 0.4578	-3.263 millimeter (mm) Standard Error 0.3983	-0.715 millimeter (mm) Standard Error 0.3984
Change From Pre-treatment Baseline in the Birch Titrated SPT Mean Wheal Diameter AUC at Day 225 and Day 253 Day 253	-4.752 millimeter (mm) Standard Error 0.3184	-4.546 millimeter (mm) Standard Error 0.3329	-2.802 millimeter (mm) Standard Error 0.3113	-0.759 millimeter (mm) Standard Error 0.3007

SECONDARY outcome

Timeframe: Day 29 from randomization (Out-of-season)

Population: All randomized participants

Titrated skin prick test (SPT) AUC= The skin prick test mean wheal diameters [mm] using serial dilutions of the allergen were used to calculate an AUC. AUC of titrated SPT mean wheal diameters were derived using the trapezoidal rule. For each participant, the AUC was calculated for the mean wheal diameter calculated over titrated concentrations of the allergen on a log scale and then normalized.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Percent Change From Pre-treatment Baseline in the Birch Titrated SPT Mean Wheal Diameter AUC at Day 29	-66.50 Percentage of Change Standard Error 4.036	-59.32 Percentage of Change Standard Error 4.689	-38.14 Percentage of Change Standard Error 4.217	-3.31 Percentage of Change Standard Error 4.223

SECONDARY outcome

Timeframe: Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

Titrated skin prick test (SPT) AUC= The skin prick test mean wheal diameters [mm] using serial dilutions of the allergen were used to calculate an AUC. AUC of titrated SPT mean wheal diameters were derived using the trapezoidal rule. For each participant, the AUC was calculated for the mean wheal diameter calculated over titrated concentrations of the allergen on a log scale and then normalized.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Percent Change From Pre-treatment Baseline in the Birch Titrated SPT Mean Wheal Diameter AUC at Day 57 and Day 85 Day 57	-64.45 Percentage of Change Standard Error 4.917	-59.19 Percentage of Change Standard Error 5.084	-37.04 Percentage of Change Standard Error 4.847	8.07 Percentage of Change Standard Error 4.765
Percent Change From Pre-treatment Baseline in the Birch Titrated SPT Mean Wheal Diameter AUC at Day 57 and Day 85 Day 85	-54.36 Percentage of Change Standard Error 5.108	-54.43 Percentage of Change Standard Error 5.079	-18.38 Percentage of Change Standard Error 5.026	7.85 Percentage of Change Standard Error 4.651

SECONDARY outcome

Timeframe: Day 127 from randomization

Population: Randomized participants with Day 127 visit (intended to be pre-season) at least 12 weeks post-randomization

Titrated skin prick test (SPT) AUC= The skin prick test mean wheal diameters [mm] using serial dilutions of the allergen were used to calculate an AUC. AUC of titrated SPT mean wheal diameters were derived using the trapezoidal rule. For each participant, the AUC was calculated for the mean wheal diameter calculated over titrated concentrations of the allergen on a log scale and then normalized.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=28 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=26 Participants Matching placebo	Placebo n=31 Participants Matching placebo	Placebo n=31 Participants Matching placebo
Percent Change From Pre-treatment Baseline in the Birch Titrated SPT Mean Wheal Diameter AUC at Day 127	-49.10 Percentage of Change Standard Error 5.715	-44.38 Percentage of Change Standard Error 6.079	-29.13 Percentage of Change Standard Error 5.506	9.30 Percentage of Change Standard Error 5.416

SECONDARY outcome

Timeframe: Day 225 from randomization (end-of-season) and Day 253 from randomization (end of study)

Population: Among randomized participants that received a second dose of study drug, the number of participants analyzed is the number of participants with a baseline measurement and post-baseline measurement. The number analyzed for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

Titrated skin prick test (SPT) AUC= The skin prick test mean wheal diameters [mm] using serial dilutions of the allergen were used to calculate an AUC. AUC of titrated SPT mean wheal diameters were derived using the trapezoidal rule. For each participant, the AUC was calculated for the mean wheal diameter calculated over titrated concentrations of the allergen on a log scale and then normalized.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=38 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=33 Participants Matching placebo	Placebo n=39 Participants Matching placebo	Placebo n=39 Participants Matching placebo
Percent Change From Pre-treatment Baseline in the Birch Titrated SPT Mean Wheal Diameter AUC at Day 225 and Day 253 Day 225	-72.42 Percentage of Change Standard Error 5.621	-57.83 Percentage of Change Standard Error 7.054	-36.74 Percentage of Change Standard Error 6.136	-6.70 Percentage of Change Standard Error 6.138
Percent Change From Pre-treatment Baseline in the Birch Titrated SPT Mean Wheal Diameter AUC at Day 225 and Day 253 Day 253	-62.71 Percentage of Change Standard Error 5.010	-60.89 Percentage of Change Standard Error 5.238	-30.98 Percentage of Change Standard Error 4.898	-5.41 Percentage of Change Standard Error 4.732

SECONDARY outcome

Timeframe: Day 36 from randomization (Out-of-season)

Population: The "Number of Participants Analyzed" is the number of participants allergic to oak with a baseline measurement and post-baseline measurement in each treatment group. The "Number Analyzed" for each scale is the number of participants with available observed data for that scale.

TNSS ranges from 0 (none) to 12 (severe): sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on a Likert scale ranging from 0 (none) to 3 (severe); Higher score indicates worse outcome. TOSS ranges from 0 (none) to 6 (severe): sum of 2 eye symptoms graded on a Likert scale each ranging from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering; Higher score indicates worse outcome. TSS ranges from 0 (none) to 18 (severe): sum of TNSS & TOSS combined; Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=29 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=28 Participants Matching placebo	Placebo n=35 Participants Matching placebo	Placebo n=30 Participants Matching placebo
Mean TNSS, TOSS and TSS (2 to 6 Hours) During Out-of-season Oak Allergen EEU Challenge at Day 36 TNSS	4.79 Scores on a Scale Standard Error 0.561	4.53 Scores on a Scale Standard Error 0.570	5.04 Scores on a Scale Standard Error 0.516	5.59 Scores on a Scale Standard Error 0.538
Mean TNSS, TOSS and TSS (2 to 6 Hours) During Out-of-season Oak Allergen EEU Challenge at Day 36 TOSS	1.86 Scores on a Scale Standard Error 0.280	2.05 Scores on a Scale Standard Error 0.284	1.78 Scores on a Scale Standard Error 0.256	2.54 Scores on a Scale Standard Error 0.270
Mean TNSS, TOSS and TSS (2 to 6 Hours) During Out-of-season Oak Allergen EEU Challenge at Day 36 TSS	6.64 Scores on a Scale Standard Error 0.804	6.57 Scores on a Scale Standard Error 0.817	6.82 Scores on a Scale Standard Error 0.738	8.08 Scores on a Scale Standard Error 0.771

SECONDARY outcome

Timeframe: Day 36 from randomization (Out-of-season)

Population: The "Number of Participants Analyzed" is the number of participants allergic to oak with a baseline measurement and post-baseline measurement in each treatment group. The "Number Analyzed" for each scale is the number of participants with available observed data for that scale.

TNSS ranges from 0 (none) to 12 (severe): sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on a Likert scale ranging from 0 (none) to 3 (severe); Higher score indicates worse outcome. TOSS ranges from 0 (none) to 6 (severe): sum of 2 eye symptoms graded on a Likert scale each ranging from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering; Higher score indicates worse outcome. TSS ranges from 0 (none) to 18 (severe): sum of TNSS & TOSS combined; Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=29 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=28 Participants Matching placebo	Placebo n=35 Participants Matching placebo	Placebo n=30 Participants Matching placebo
Change From Pre-treatment Baseline in TNSS, TOSS and TSS (2 to 6 Hours) During Oak Allergen EEU Challenge at Day 36 TSS	-3.97 Scores on a Scale Standard Error 0.804	-4.04 Scores on a Scale Standard Error 0.817	-3.79 Scores on a Scale Standard Error 0.738	-2.53 Scores on a Scale Standard Error 0.771
Change From Pre-treatment Baseline in TNSS, TOSS and TSS (2 to 6 Hours) During Oak Allergen EEU Challenge at Day 36 TNSS	-2.63 Scores on a Scale Standard Error 0.561	-2.89 Scores on a Scale Standard Error 0.570	-2.38 Scores on a Scale Standard Error 0.516	-1.83 Scores on a Scale Standard Error 0.538
Change From Pre-treatment Baseline in TNSS, TOSS and TSS (2 to 6 Hours) During Oak Allergen EEU Challenge at Day 36 TOSS	-1.33 Scores on a Scale Standard Error 0.280	-1.14 Scores on a Scale Standard Error 0.284	-1.41 Scores on a Scale Standard Error 0.256	-0.65 Scores on a Scale Standard Error 0.270

SECONDARY outcome

Timeframe: Day 36 from randomization (Out-of-season)

Population: The "Number of Participants Analyzed" is the number of participants allergic to oak with a baseline measurement and post-baseline measurement in each treatment group. The "Number Analyzed" for each scale is the number of participants with available observed data for that scale.

TNSS ranges from 0 (none) to 12 (severe): sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on a Likert scale ranging from 0 (none) to 3 (severe); Higher score indicates worse outcome. TOSS ranges from 0 (none) to 6 (severe): sum of 2 eye symptoms graded on a Likert scale each ranging from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering; Higher score indicates worse outcome. TSS ranges from 0 (none) to 18 (severe): sum of TNSS & TOSS combined; Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=29 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=28 Participants Matching placebo	Placebo n=35 Participants Matching placebo	Placebo n=30 Participants Matching placebo
Percent Change From Pre-treatment Baseline in TNSS, TOSS and TSS (2 to 6 Hours) During Oak Allergen EEU Challenge at Day 36 TNSS	-35.18 Percentage of Change Standard Error 7.448	-34.95 Percentage of Change Standard Error 7.572	-30.36 Percentage of Change Standard Error 6.848	-20.46 Percentage of Change Standard Error 7.144
Percent Change From Pre-treatment Baseline in TNSS, TOSS and TSS (2 to 6 Hours) During Oak Allergen EEU Challenge at Day 36 TOSS	-52.74 Percentage of Change Standard Error 9.947	-32.95 Percentage of Change Standard Error 10.097	-49.39 Percentage of Change Standard Error 9.113	-15.45 Percentage of Change Standard Error 9.589
Percent Change From Pre-treatment Baseline in TNSS, TOSS and TSS (2 to 6 Hours) During Oak Allergen EEU Challenge at Day 36 TSS	-38.98 Percentage of Change Standard Error 7.471	-33.81 Percentage of Change Standard Error 7.590	-35.14 Percentage of Change Standard Error 6.858	-19.25 Percentage of Change Standard Error 7.167

SECONDARY outcome

Timeframe: Day 29, Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

TNSS ranges from 0 (none) to 12 (severe): sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on a Likert scale ranging from 0 (none) to 3 (severe); Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=55 Participants Matching placebo	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TNSS (2 to 6 Hours) Response Thresholds Day 29 Participants with a percent reduction of at least 75% or greater	2 Participants	1 Participants	11 Participants	9 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TNSS (2 to 6 Hours) Response Thresholds Day 29 Participants with a percent reduction of at least 50% or greater	7 Participants	13 Participants	23 Participants	23 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TNSS (2 to 6 Hours) Response Thresholds Day 29 Participants with a percent reduction of at least 25% or greater	13 Participants	31 Participants	31 Participants	40 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TNSS (2 to 6 Hours) Response Thresholds Day 57 Participants with a percent reduction of at least 75% or greater	3 Participants	6 Participants	13 Participants	6 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TNSS (2 to 6 Hours) Response Thresholds Day 57 Participants with a percent reduction of at least 50% or greater	7 Participants	14 Participants	21 Participants	17 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TNSS (2 to 6 Hours) Response Thresholds Day 57 Participants with a percent reduction of at least 25% or greater	15 Participants	27 Participants	30 Participants	31 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TNSS (2 to 6 Hours) Response Thresholds Day 85 Participants with a percent reduction of at least 75% or greater	4 Participants	7 Participants	10 Participants	7 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TNSS (2 to 6 Hours) Response Thresholds Day 85 Participants with a percent reduction of at least 50% or greater	9 Participants	15 Participants	18 Participants	15 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TNSS (2 to 6 Hours) Response Thresholds Day 85 Participants with a percent reduction of at least 25% or greater	17 Participants	26 Participants	26 Participants	30 Participants

SECONDARY outcome

Timeframe: Day 29, Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

TOSS ranges from 0 (none) to 6 (severe): sum of 2 eye symptoms graded on a Likert scale each ranging from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering; Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=55 Participants Matching placebo	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TOSS (2 to 6 Hours) Response Thresholds Day 29 Participants with a percent reduction of at least 75% or greater	8 Participants	6 Participants	12 Participants	16 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TOSS (2 to 6 Hours) Response Thresholds Day 29 Participants with a percent reduction of at least 50% or greater	10 Participants	18 Participants	20 Participants	28 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TOSS (2 to 6 Hours) Response Thresholds Day 29 Participants with a percent reduction of at least 25% or greater	22 Participants	34 Participants	29 Participants	38 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TOSS (2 to 6 Hours) Response Thresholds Day 57 Participants with a percent reduction of at least 75% or greater	7 Participants	10 Participants	20 Participants	20 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TOSS (2 to 6 Hours) Response Thresholds Day 57 Participants with a percent reduction of at least 50% or greater	9 Participants	22 Participants	25 Participants	27 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TOSS (2 to 6 Hours) Response Thresholds Day 57 Participants with a percent reduction of at least 25% or greater	17 Participants	26 Participants	26 Participants	31 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TOSS (2 to 6 Hours) Response Thresholds Day 85 Participants with a percent reduction of at least 75% or greater	5 Participants	10 Participants	14 Participants	11 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TOSS (2 to 6 Hours) Response Thresholds Day 85 Participants with a percent reduction of at least 50% or greater	13 Participants	21 Participants	19 Participants	20 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TOSS (2 to 6 Hours) Response Thresholds Day 85 Participants with a percent reduction of at least 25% or greater	18 Participants	30 Participants	24 Participants	30 Participants

SECONDARY outcome

Timeframe: Day 29, Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

TSS ranges from 0 (none) to 18 (severe): sum of TNSS & TOSS combined; Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=55 Participants Matching placebo	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TSS (2 to 6 Hours) Response Thresholds Day 29 Participants with a percent reduction of at least 75% or greater	3 Participants	2 Participants	11 Participants	11 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TSS (2 to 6 Hours) Response Thresholds Day 29 Participants with a percent reduction of at least 50% or greater	7 Participants	13 Participants	23 Participants	21 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TSS (2 to 6 Hours) Response Thresholds Day 29 Participants with a percent reduction of at least 25% or greater	13 Participants	30 Participants	29 Participants	40 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TSS (2 to 6 Hours) Response Thresholds Day 57 Participants with a percent reduction of at least 75% or greater	3 Participants	4 Participants	14 Participants	9 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TSS (2 to 6 Hours) Response Thresholds Day 57 Participants with a percent reduction of at least 50% or greater	7 Participants	15 Participants	23 Participants	22 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TSS (2 to 6 Hours) Response Thresholds Day 57 Participants with a percent reduction of at least 25% or greater	15 Participants	25 Participants	29 Participants	32 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TSS (2 to 6 Hours) Response Thresholds Day 85 Participants with a percent reduction of at least 75% or greater	4 Participants	7 Participants	8 Participants	8 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TSS (2 to 6 Hours) Response Thresholds Day 85 Participants with a percent reduction of at least 50% or greater	8 Participants	14 Participants	18 Participants	16 Participants
Number of Participants Achieving Different Degrees of Clinical Responses Compared Across TSS (2 to 6 Hours) Response Thresholds Day 85 Participants with a percent reduction of at least 25% or greater	18 Participants	29 Participants	25 Participants	32 Participants

SECONDARY outcome

Timeframe: Day 29, Day 57 and Day 85, from randomization (Out-of-season)

Population: The overall "Number of Participants Analyzed" is the total number of randomized participants in each treatment group. The "Number Analyzed" for each timepoint is the number of participants with available observed data that were analyzed at that timepoint.

Titrated skin prick test (SPT) AUC= The skin prick test mean wheal diameters [mm] using serial dilutions of the allergen were used to calculate an AUC. AUC of titrated SPT mean wheal diameters were derived using the trapezoidal rule. For each participant, the AUC was calculated for the mean wheal diameter calculated over titrated concentrations of the allergen on a log scale and then normalized.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=55 Participants Matching placebo	Placebo n=52 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Number of Participants Achieving Different Degrees of Responses in the Birch Titrated SPT Mean Wheal Diameter AUC Compared Across Different Response Thresholds Day 57 Participants with a percent reduction of at least 75% or greater	0 Participants	1 Participants	4 Participants	12 Participants
Number of Participants Achieving Different Degrees of Responses in the Birch Titrated SPT Mean Wheal Diameter AUC Compared Across Different Response Thresholds Day 29 Participants with a percent reduction of at least 75% or greater	1 Participants	1 Participants	8 Participants	19 Participants
Number of Participants Achieving Different Degrees of Responses in the Birch Titrated SPT Mean Wheal Diameter AUC Compared Across Different Response Thresholds Day 29 Participants with a percent reduction of at least 50% or greater	1 Participants	12 Participants	24 Participants	41 Participants
Number of Participants Achieving Different Degrees of Responses in the Birch Titrated SPT Mean Wheal Diameter AUC Compared Across Different Response Thresholds Day 29 Participants with a percent reduction of at least 25% or greater	11 Participants	34 Participants	35 Participants	50 Participants
Number of Participants Achieving Different Degrees of Responses in the Birch Titrated SPT Mean Wheal Diameter AUC Compared Across Different Response Thresholds Day 57 Participants with a percent reduction of at least 50% or greater	1 Participants	9 Participants	27 Participants	25 Participants
Number of Participants Achieving Different Degrees of Responses in the Birch Titrated SPT Mean Wheal Diameter AUC Compared Across Different Response Thresholds Day 57 Participants with a percent reduction of at least 25% or greater	5 Participants	29 Participants	34 Participants	40 Participants
Number of Participants Achieving Different Degrees of Responses in the Birch Titrated SPT Mean Wheal Diameter AUC Compared Across Different Response Thresholds Day 85 Participants with a percent reduction of at least 75% or greater	0 Participants	0 Participants	11 Participants	8 Participants
Number of Participants Achieving Different Degrees of Responses in the Birch Titrated SPT Mean Wheal Diameter AUC Compared Across Different Response Thresholds Day 85 Participants with a percent reduction of at least 50% or greater	1 Participants	2 Participants	21 Participants	25 Participants
Number of Participants Achieving Different Degrees of Responses in the Birch Titrated SPT Mean Wheal Diameter AUC Compared Across Different Response Thresholds Day 85 Participants with a percent reduction of at least 25% or greater	5 Participants	17 Participants	31 Participants	32 Participants

SECONDARY outcome

Timeframe: Day 190 from randomization (In-season); Timing may vary based on local season

Population: The "Number of Participants Analyzed" is the number of participants who received a second dose of the study drug. The "Number Analyzed" for each scale is the number of participants with available observed data for that scale.

Peak season EEU is an in-season challenge corresponding to approximate timing of the anticipated peak BPS; TNSS ranges from 0 (none) to 12 (severe): sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on a Likert scale ranging from 0 (none) to 3 (severe); Higher score indicates worse outcome. TOSS ranges from 0 (none) to 6 (severe): sum of 2 eye symptoms graded on a Likert scale each ranging from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering; Higher score indicates worse outcome. TSS ranges from 0 (none) to 18 (severe): sum of TNSS & TOSS combined; Higher score indicates worse outcome.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=38 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=33 Participants Matching placebo	Placebo n=37 Participants Matching placebo	Placebo n=38 Participants Matching placebo
Mean TNSS, TOSS and TSS (2 to 6 Hours) During Peak-season Birch Allergen EEU Challenge at Day 190 TNSS	4.49 Scores on a Scale Standard Error 0.497	4.41 Scores on a Scale Standard Error 0.520	5.07 Scores on a Scale Standard Error 0.497	6.69 Scores on a Scale Standard Error 0.469
Mean TNSS, TOSS and TSS (2 to 6 Hours) During Peak-season Birch Allergen EEU Challenge at Day 190 TOSS	1.90 Scores on a Scale Standard Error 0.246	1.85 Scores on a Scale Standard Error 0.257	1.83 Scores on a Scale Standard Error 0.245	2.68 Scores on a Scale Standard Error 0.232
Mean TNSS, TOSS and TSS (2 to 6 Hours) During Peak-season Birch Allergen EEU Challenge at Day 190 TSS	6.39 Scores on a Scale Standard Error 0.692	6.26 Scores on a Scale Standard Error 0.724	6.92 Scores on a Scale Standard Error 0.690	9.36 Scores on a Scale Standard Error 0.653

SECONDARY outcome

Timeframe: Up to 253 days from randomization (during BPS)

Population: The "Number of Participants Analyzed" is the number of participants who received a second dose of the study drug. The "Number Analyzed" for each scale is the number of participants with available observed data for that scale.

TNSS ranges from 0 (none) to 12 (severe): Sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on a Likert scale from 0 (none) to 3 (severe); Higher score indicates worse outcome. TOSS ranges from 0 (none) to 6 (severe): Sum of 2 eye symptoms graded on Likert scale each from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering; Higher score indicates worse outcome. TSS ranges from 0 (none) to 18 (severe): Sum of TNSS & TOSS; Higher score indicates worse outcome. DMS ranges from 0 to 20 (max points): Sum for each pre-specified medication taken as oral antihistamine 6 points/dose (max daily score 6), ocular antihistamine 1.5 points/drop (max daily score 6), intranasal corticosteroid 2.0 points/spray (max daily score 8). CSMS ranges from 0 to 38 (max): Sum of DMS & TSS higher score indicates worse outcome). Daily TNSS, TOSS, TSS, DMS & CSMS each averaged over duration of birch pollen season presented.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=38 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=33 Participants Matching placebo	Placebo n=39 Participants Matching placebo	Placebo n=39 Participants Matching placebo
Daily Averaged TNSS, TOSS, TSS, Daily Medication Score (DMS) and Combined Symptom and Medication Score (CSMS) During Birch Pollen Season (BPS) TNSS	3.38 Scores on a Scale Standard Error 0.422	3.44 Scores on a Scale Standard Error 0.443	3.57 Scores on a Scale Standard Error 0.413	4.05 Scores on a Scale Standard Error 0.399
Daily Averaged TNSS, TOSS, TSS, Daily Medication Score (DMS) and Combined Symptom and Medication Score (CSMS) During Birch Pollen Season (BPS) TOSS	1.09 Scores on a Scale Standard Error 0.199	1.15 Scores on a Scale Standard Error 0.210	1.16 Scores on a Scale Standard Error 0.195	1.62 Scores on a Scale Standard Error 0.188
Daily Averaged TNSS, TOSS, TSS, Daily Medication Score (DMS) and Combined Symptom and Medication Score (CSMS) During Birch Pollen Season (BPS) TSS	4.48 Scores on a Scale Standard Error 0.595	4.59 Scores on a Scale Standard Error 0.625	4.73 Scores on a Scale Standard Error 0.582	5.65 Scores on a Scale Standard Error 0.563
Daily Averaged TNSS, TOSS, TSS, Daily Medication Score (DMS) and Combined Symptom and Medication Score (CSMS) During Birch Pollen Season (BPS) DMS	0.84 Scores on a Scale Standard Error 0.439	0.89 Scores on a Scale Standard Error 0.457	1.05 Scores on a Scale Standard Error 0.426	1.74 Scores on a Scale Standard Error 0.408
Daily Averaged TNSS, TOSS, TSS, Daily Medication Score (DMS) and Combined Symptom and Medication Score (CSMS) During Birch Pollen Season (BPS) CSMS	5.350 Scores on a Scale Standard Error 0.8912	5.509 Scores on a Scale Standard Error 0.9352	5.776 Scores on a Scale Standard Error 0.8710	7.392 Scores on a Scale Standard Error 0.8433

SECONDARY outcome

Timeframe: Up to 253 days from randomization (during peak BPS)

Population: The "Number of Participants Analyzed" is the number of participants who received a second dose of the study drug. The "Number Analyzed" for each scale is the number of participants with available observed data for that scale.

TNSS ranges from 0 (none) to 12 (severe): Sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on a Likert scale from 0 (none) to 3 (severe); Higher score indicates worse outcome. TOSS ranges from 0 (none) to 6 (severe): Sum of 2 eye symptoms graded on Likert scale each from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering; Higher score indicates worse outcome. TSS ranges from 0 (none) to 18 (severe): Sum of TNSS & TOSS; Higher score indicates worse outcome. DMS ranges from 0 to 20 (max points): Sum for each pre-specified medication taken as oral antihistamine 6 points/dose (max daily score 6), ocular antihistamine 1.5 points/drop (max daily score 6), intranasal corticosteroid 2.0 points/spray (max daily score 8). CSMS ranges from 0 to 38 (max): Sum of DMS & TSS higher score indicates worse outcome). Daily TNSS, TOSS, TSS, DMS & CSMS each averaged over duration of peak birch pollen season presented.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=37 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=33 Participants Matching placebo	Placebo n=39 Participants Matching placebo	Placebo n=39 Participants Matching placebo
Daily Averaged TNSS, TOSS, TSS, DMS and CSMS During Peak BPS TNNS	3.79 Scores on a Scale Standard Error 0.483	3.87 Scores on a Scale Standard Error 0.502	3.71 Scores on a Scale Standard Error 0.469	4.67 Scores on a Scale Standard Error 0.452
Daily Averaged TNSS, TOSS, TSS, DMS and CSMS During Peak BPS TOSS	1.24 Scores on a Scale Standard Error 0.230	1.32 Scores on a Scale Standard Error 0.238	1.25 Scores on a Scale Standard Error 0.223	1.87 Scores on a Scale Standard Error 0.214
Daily Averaged TNSS, TOSS, TSS, DMS and CSMS During Peak BPS TSS	5.03 Scores on a Scale Standard Error 0.679	5.18 Scores on a Scale Standard Error 0.705	4.96 Scores on a Scale Standard Error 0.659	6.53 Scores on a Scale Standard Error 0.635
Daily Averaged TNSS, TOSS, TSS, DMS and CSMS During Peak BPS DMS	0.94 Scores on a Scale Standard Error 0.504	1.18 Scores on a Scale Standard Error 0.517	1.11 Scores on a Scale Standard Error 0.485	1.99 Scores on a Scale Standard Error 0.463
Daily Averaged TNSS, TOSS, TSS, DMS and CSMS During Peak BPS CSMS	5.997 Scores on a Scale Standard Error 1.0154	6.357 Scores on a Scale Standard Error 1.0525	6.055 Scores on a Scale Standard Error 0.9842	8.501 Scores on a Scale Standard Error 0.9500

SECONDARY outcome

Timeframe: Up to 253 days from randomization (during BPS)

Population: The "Number of Participants Analyzed" is the number of participants who received a second dose of the study drug. The "Number Analyzed" for each scale is the number of participants with available observed data for that scale.

TNSS ranges from 0 (none) to 12 (severe): Sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on a Likert scale from 0 (none) to 3 (severe); Higher score indicates worse outcome. TOSS ranges from 0 (none) to 6 (severe): Sum of 2 eye symptoms graded on Likert scale each from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering; Higher score indicates worse outcome. TSS ranges from 0 (none) to 18 (severe): Sum of TNSS & TOSS; Higher score indicates worse outcome. DMS ranges from 0 to 20 (max points): Sum for pre-specified medication taken as oral antihistamine 6 points/dose (max daily score 6), ocular antihistamine 1.5 points/drop (max daily score 6), intranasal corticosteroid 2.0 points/spray (max daily score 8). CSMS ranges from 0 to 38 (max): Sum of DMS & TSS; Higher score indicates worse outcome. Change from pre-treatment baseline in TNSS, TOSS, TSS, DMS & CSMS each averaged over duration of birch pollen season presented.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=38 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=33 Participants Matching placebo	Placebo n=39 Participants Matching placebo	Placebo n=39 Participants Matching placebo
Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During BPS TNSS	1.38 Scores on a Scale Standard Error 0.422	1.44 Scores on a Scale Standard Error 0.443	1.57 Scores on a Scale Standard Error 0.413	2.05 Scores on a Scale Standard Error 0.399
Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During BPS TOSS	0.54 Scores on a Scale Standard Error 0.199	0.60 Scores on a Scale Standard Error 0.210	0.61 Scores on a Scale Standard Error 0.195	1.06 Scores on a Scale Standard Error 0.188
Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During BPS TSS	1.93 Scores on a Scale Standard Error 0.595	2.03 Scores on a Scale Standard Error 0.625	2.18 Scores on a Scale Standard Error 0.582	3.10 Scores on a Scale Standard Error 0.563
Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During BPS DMS	0.78 Scores on a Scale Standard Error 0.439	0.83 Scores on a Scale Standard Error 0.457	0.98 Scores on a Scale Standard Error 0.426	1.68 Scores on a Scale Standard Error 0.408
Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During BPS CSMS	2.733 Scores on a Scale Standard Error 0.8912	2.891 Scores on a Scale Standard Error 0.9352	3.158 Scores on a Scale Standard Error 0.8710	4.775 Scores on a Scale Standard Error 0.8433

SECONDARY outcome

Timeframe: Up to 253 days from randomization (during peak BPS)

Population: The "Number of Participants Analyzed" is the number of participants who received a second dose of the study drug. The "Number Analyzed" for each scale is the number of participants with available observed data for that scale.

TNSS ranges from 0 (none) to 12 (severe): Sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on Likert scale from 0 (none) to 3 (severe); Higher score indicates worse outcome. TOSS ranges from 0 (none) to 6 (severe): Sum of 2 eye symptoms graded on Likert scale each from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering; Higher score indicates worse outcome. TSS ranges from 0 (none) to 18 (severe): Sum of TNSS & TOSS; Higher score indicates worse outcome. DMS ranges from 0 to 20 (max points): Sum for pre-specified medication taken as oral antihistamine 6 points/dose (max daily score 6), ocular antihistamine 1.5 points/drop (max daily score 6), intranasal corticosteroid 2.0 points/spray (max daily score 8). CSMS ranges from 0 to 38 (max): Sum of DMS & TSS; Higher score indicates worse outcome. Change from pre-treatment baseline in TNSS, TOSS, TSS, DMS & CSMS each averaged over duration of peak birch pollen season presented.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=37 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=33 Participants Matching placebo	Placebo n=39 Participants Matching placebo	Placebo n=39 Participants Matching placebo
Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During Peak BPS TNSS	1.79 Scores on a Scale Standard Error 0.483	1.86 Scores on a Scale Standard Error 0.502	1.71 Scores on a Scale Standard Error 0.469	2.66 Scores on a Scale Standard Error 0.452
Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During Peak BPS TOSS	0.69 Scores on a Scale Standard Error 0.230	0.77 Scores on a Scale Standard Error 0.238	0.70 Scores on a Scale Standard Error 0.223	1.32 Scores on a Scale Standard Error 0.214
Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During Peak BPS TSS	2.48 Scores on a Scale Standard Error 0.679	2.62 Scores on a Scale Standard Error 0.705	2.40 Scores on a Scale Standard Error 0.659	3.97 Scores on a Scale Standard Error 0.635
Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During Peak BPS DMS	0.88 Scores on a Scale Standard Error 0.504	1.11 Scores on a Scale Standard Error 0.517	1.04 Scores on a Scale Standard Error 0.485	1.93 Scores on a Scale Standard Error 0.463
Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During Peak BPS CSMS	3.376 Scores on a Scale Standard Error 1.0154	3.736 Scores on a Scale Standard Error 1.0525	3.434 Scores on a Scale Standard Error 0.9842	5.880 Scores on a Scale Standard Error 0.9500

SECONDARY outcome

Timeframe: Up to 253 days from randomization (during BPS)

Population: The "Number of Participants Analyzed" is the number of participants who received a second dose of the study drug. The "Number Analyzed" for each scale is the number of participants with available observed data for that scale.

TNSS range from 0 (none) to 12 (severe): Sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on Likert scale from 0 (none) to 3 (severe); Higher score indicates worse outcome. TOSS range from 0 (none) to 6 (severe): Sum of 2 eye symptoms graded on Likert scale each from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering; Higher score indicates worse outcome. TSS range from 0 (none) to 18 (severe): Sum of TNSS & TOSS; Higher score indicates worse outcome. DMS range from 0 to 20 (max points): Sum for pre-specified medication taken as oral antihistamine 6 points/dose (max daily score 6), ocular antihistamine 1.5 points/drop (max daily score 6), intranasal corticosteroid 2.0 points/spray (max daily score 8). CSMS range from 0 to 38 (max): Sum of DMS & TSS; Higher score indicates worse outcome. Percent change from pre-treatment baseline in TNSS, TOSS, TSS, DMS & CSMS each averaged over duration of birch pollen season presented.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=38 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=33 Participants Matching placebo	Placebo n=39 Participants Matching placebo	Placebo n=39 Participants Matching placebo
Percent Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During BPS TNSS	86.55 Percentage of Change Standard Error 32.120	81.60 Percentage of Change Standard Error 33.741	112.71 Percentage of Change Standard Error 31.414	120.74 Percentage of Change Standard Error 30.384
Percent Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During BPS TOSS	-2.85 Percentage of Change Standard Error 18.480	-0.66 Percentage of Change Standard Error 19.426	2.78 Percentage of Change Standard Error 18.078	44.16 Percentage of Change Standard Error 17.452
Percent Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During BPS TSS	126.46 Percentage of Change Standard Error 42.830	128.85 Percentage of Change Standard Error 45.018	147.59 Percentage of Change Standard Error 41.886	177.04 Percentage of Change Standard Error 40.526
Percent Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During BPS DMS	-17.06 Percentage of Change Standard Error 43.686	-15.13 Percentage of Change Standard Error 45.431	2.66 Percentage of Change Standard Error 42.367	70.85 Percentage of Change Standard Error 40.614
Percent Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During BPS CSMS	147.47 Percentage of Change Standard Error 65.846	187.32 Percentage of Change Standard Error 69.092	219.64 Percentage of Change Standard Error 64.352	263.58 Percentage of Change Standard Error 62.302

SECONDARY outcome

Timeframe: Up to 253 days from randomization (during peak BPS)

Population: The "Number of Participants Analyzed" is the number of participants who received a second dose of the study drug. The "Number Analyzed" for each scale is the number of participants with available observed data for that scale.

TNSS range from 0 (none) to 12 (severe): Sum of 4 nasal symptoms (nasal congestion, itching, & runny nose, & sneezing) graded on Likert scale from 0 (none) to 3 (severe);Higher score indicates worse outcome. TOSS range from 0 (none) to 6 (severe): Sum of 2 eye symptoms graded on Likert scale each from 0 (none) to 3 (severe) for itching/redness/gritty feeling & tearing/watering;Higher score indicates worse outcome. TSS range from 0 (none) to 18 (severe): Sum of TNSS & TOSS;Higher score indicates worse outcome. DMS range from 0 to 20 (max points): Sum for pre-specified medication taken as oral antihistamine 6 points/dose (max daily score 6), ocular antihistamine 1.5 points/drop (max daily score 6), intranasal corticosteroid 2.0 points/spray (max daily score 8). CSMS range from 0 to 38 (max): Sum of DMS & TSS;Higher score indicates worse outcome. Percent change from pre-treatment baseline in TNSS, TOSS, TSS, DMS & CSMS each averaged over duration of peak birch pollen season presented.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=37 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=33 Participants Matching placebo	Placebo n=39 Participants Matching placebo	Placebo n=39 Participants Matching placebo
Percent Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During Peak BPS TNSS	103.41 Percentage of Change Standard Error 36.254	110.33 Percentage of Change Standard Error 37.612	121.50 Percentage of Change Standard Error 35.160	166.54 Percentage of Change Standard Error 33.905
Percent Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During Peak BPS TOSS	9.74 Percentage of Change Standard Error 21.416	14.03 Percentage of Change Standard Error 22.233	10.21 Percentage of Change Standard Error 20.773	68.18 Percentage of Change Standard Error 19.993
Percent Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During Peak BPS TSS	143.52 Percentage of Change Standard Error 48.745	165.35 Percentage of Change Standard Error 50.606	157.81 Percentage of Change Standard Error 47.273	234.84 Percentage of Change Standard Error 45.601
Percent Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During Peak BPS DMS	-7.34 Percentage of Change Standard Error 50.188	13.02 Percentage of Change Standard Error 51.510	8.63 Percentage of Change Standard Error 48.254	95.84 Percentage of Change Standard Error 46.109
Percent Change From Pre-treatment Baseline in TNSS, TOSS, TSS, DMS and CSMS Averaged During Peak BPS CSMS	164.04 Percentage of Change Standard Error 76.371	246.04 Percentage of Change Standard Error 79.156	227.73 Percentage of Change Standard Error 74.021	340.82 Percentage of Change Standard Error 71.451

SECONDARY outcome

Timeframe: Up to 253 days from randomization (during BPS)

Population: Randomized participants who received a second dose of the study drug

The RQLQ(S) is a self-administered questionnaire to measure health-related quality of life in those 12 years of age and above, as a result of perennial or seasonal allergic rhinitis. There are 28 items in 7 domains: activity limitation, sleep problems, nasal symptoms, eye symptoms, non-nasal/eye symptoms, practical problems, and emotional function with responses based on a 7-point Likert scale ranging from 0 (not troubled) to 6 (extremely troubled). Overall RQLQ(S) score is the mean of all 28 responses and the individual domain scores are the means of the items in those domains. Higher scores indicate more health-related quality of life impairment (lower scores are better). Overall RQLQ(S) score averaged over duration of birch pollen season presented.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=38 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=33 Participants Matching placebo	Placebo n=39 Participants Matching placebo	Placebo n=39 Participants Matching placebo
Standardized Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ[S]) Score Averaged During BPS	0.98 Scores on a Scale Standard Error 0.205	0.98 Scores on a Scale Standard Error 0.215	1.11 Scores on a Scale Standard Error 0.197	1.29 Scores on a Scale Standard Error 0.189

SECONDARY outcome

Timeframe: Up to 253 days from randomization (during peak BPS)

Population: Randomized participants who received a second dose of the study drug

The RQLQ(S) is a self-administered questionnaire to measure health-related quality of life in those 12 years of age and above, as a result of perennial or seasonal allergic rhinitis. There are 28 items in 7 domains: activity limitation, sleep problems, nasal symptoms, eye symptoms, non-nasal/eye symptoms, practical problems, and emotional function with responses based on a 7-point Likert scale ranging from 0 (not troubled) to 6 (extremely troubled). Overall RQLQ(S) score is the mean of all 28 responses and the individual domain scores are the means of the items in those domains. Higher scores indicate more health-related quality of life impairment (lower scores are better). Overall RQLQ(S) score averaged over duration of peak birch pollen season presented.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=38 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=33 Participants Matching placebo	Placebo n=39 Participants Matching placebo	Placebo n=39 Participants Matching placebo
Standardized RQLQ(S) Score Averaged During Peak BPS	1.04 Scores on a Scale Standard Error 0.229	1.14 Scores on a Scale Standard Error 0.239	1.25 Scores on a Scale Standard Error 0.220	1.62 Scores on a Scale Standard Error 0.215

SECONDARY outcome

Timeframe: Up to 253 days from randomization (during BPS)

Population: Randomized participants who received a second dose of the study drug

The RQLQ(S) is a self-administered questionnaire to measure health-related quality of life in those 12 years of age and above, as a result of perennial or seasonal allergic rhinitis. There are 28 items in 7 domains: activity limitation, sleep problems, nasal symptoms, eye symptoms, non-nasal/eye symptoms, practical problems, and emotional function with responses based on a 7-point Likert scale ranging from 0 (not troubled) to 6 (extremely troubled). Overall RQLQ(S) score is the mean of all 28 responses and the individual domain scores are the means of the items in those domains. Higher scores indicate more health-related quality of life impairment (lower scores are better). Change from pre-treatment baseline averaged over duration of birch pollen season presented.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=37 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=32 Participants Matching placebo	Placebo n=39 Participants Matching placebo	Placebo n=39 Participants Matching placebo
Change From Pre-treatment Baseline in the Average RQLQ(S) Score During BPS	-0.11 Scores on a Scale Standard Error 0.205	-0.11 Scores on a Scale Standard Error 0.215	0.02 Scores on a Scale Standard Error 0.197	0.20 Scores on a Scale Standard Error 0.189

SECONDARY outcome

Timeframe: Up to 253 days from randomization (during peak BPS)

Population: Randomized participants who received a second dose of the study drug

The RQLQ(S) is a self-administered questionnaire to measure health-related quality of life in those 12 years of age and above, as a result of perennial or seasonal allergic rhinitis. There are 28 items in 7 domains: activity limitation, sleep problems, nasal symptoms, eye symptoms, non-nasal/eye symptoms, practical problems, and emotional function with responses based on a 7-point Likert scale ranging from 0 (not troubled) to 6 (extremely troubled). Overall RQLQ(S) score is the mean of all 28 responses and the individual domain scores are the means of the items in those domains. Higher scores indicate more health-related quality of life impairment (lower scores are better). Change from pre-treatment baseline averaged over duration of peak birch pollen season presented.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=36 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=32 Participants Matching placebo	Placebo n=39 Participants Matching placebo	Placebo n=38 Participants Matching placebo
Change From Pre-treatment Baseline in the Average RQLQ(S) Score During Peak BPS	-0.04 Scores on a Scale Standard Error 0.229	0.05 Scores on a Scale Standard Error 0.239	0.16 Scores on a Scale Standard Error 0.220	0.54 Scores on a Scale Standard Error 0.215

SECONDARY outcome

Timeframe: Up to 253 days from randomization (during BPS)

Population: Randomized participants who received a second dose of the study drug

The RQLQ(S) is a self-administered questionnaire to measure health-related quality of life in those 12 years of age and above, as a result of perennial or seasonal allergic rhinitis. There are 28 items in 7 domains: activity limitation, sleep problems, nasal symptoms, eye symptoms, non-nasal/eye symptoms, practical problems, and emotional function with responses based on a 7-point Likert scale ranging from 0 (not troubled) to 6 (extremely troubled). Overall RQLQ(S) score is the mean of all 28 responses and the individual domain scores are the means of the items in those domains. Higher scores indicate more health-related quality of life impairment (lower scores are better). Percent change from pre-treatment baseline averaged over duration of birch pollen season presented.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=37 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=32 Participants Matching placebo	Placebo n=39 Participants Matching placebo	Placebo n=39 Participants Matching placebo
Percent Change From Pre-treatment Baseline in the Average RQLQ(S) Score During BPS	-32.68 Percentage of Change Standard Error 16.904	-22.84 Percentage of Change Standard Error 17.780	-12.70 Percentage of Change Standard Error 16.298	2.06 Percentage of Change Standard Error 15.598

SECONDARY outcome

Timeframe: Up to 253 days from randomization (during peak BPS)

Population: Randomized participants who received a second dose of the study drug

The RQLQ(S) is a self-administered questionnaire to measure health-related quality of life in those 12 years of age and above, as a result of perennial or seasonal allergic rhinitis. There are 28 items in 7 domains: activity limitation, sleep problems, nasal symptoms, eye symptoms, non-nasal/eye symptoms, practical problems, and emotional function with responses based on a 7-point Likert scale ranging from 0 (not troubled) to 6 (extremely troubled). Overall RQLQ(S) score is the mean of all 28 responses and the individual domain scores are the means of the items in those domains. Higher scores indicate more health-related quality of life impairment (lower scores are better). Percent change from pre-treatment baseline averaged over duration of peak birch pollen season presented.

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=36 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=32 Participants Matching placebo	Placebo n=39 Participants Matching placebo	Placebo n=38 Participants Matching placebo
Percent Change From Pre-treatment Baseline in the Average RQLQ(S) Score During Peak BPS	-27.67 Percentage of Change Standard Error 19.220	-9.90 Percentage of Change Standard Error 20.000	-1.67 Percentage of Change Standard Error 18.446	29.24 Percentage of Change Standard Error 17.972

SECONDARY outcome

Timeframe: Up to 253 Days

Population: Randomized participants who receive any study drug, regardless of the amount of treatment administered

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=55 Participants Matching placebo	Placebo n=51 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Number of Participants With Any Treatment-Emergent Adverse Event (TEAE) Over the Study Duration	26 Participants	23 Participants	23 Participants	25 Participants

SECONDARY outcome

Timeframe: Up to 253 Days

Population: Randomized participants who receive any study drug, regardless of the amount of treatment administered

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=55 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=55 Participants Matching placebo	Placebo n=51 Participants Matching placebo	Placebo n=55 Participants Matching placebo
Number of Participants With Any Treatment-Emergent Serious AE (TESAE) Over the Study Duration	0 Participants	0 Participants	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Up to Week 36

Population: Randomized and treated participants who received REGN5713 and contributed to each timepoint

Outcome measures

Measure	REGN5713-5714-5715 900 mg 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=45 Participants Matching placebo	Placebo n=54 Participants Matching placebo	Placebo Matching placebo
Serum Concentration of REGN5713 Over the Study Duration Baseline	—	0 mg/L Standard Deviation 0	0 mg/L Standard Deviation 0	—
Serum Concentration of REGN5713 Over the Study Duration Week 4	—	15.2 mg/L Standard Deviation 4.72	16.2 mg/L Standard Deviation 5.23	—
Serum Concentration of REGN5713 Over the Study Duration Week 8	—	7.10 mg/L Standard Deviation 2.69	8.12 mg/L Standard Deviation 3.59	—
Serum Concentration of REGN5713 Over the Study Duration Week 12	—	4.72 mg/L Standard Deviation 2.37	5.25 mg/L Standard Deviation 3.09	—
Serum Concentration of REGN5713 Over the Study Duration Week 18	—	2.18 mg/L Standard Deviation 1.80	2.84 mg/L Standard Deviation 2.60	—
Serum Concentration of REGN5713 Over the Study Duration Week 22	—	1.42 mg/L Standard Deviation 1.27	2.04 mg/L Standard Deviation 2.36	—
Serum Concentration of REGN5713 Over the Study Duration Week 27	—	16.9 mg/L Standard Deviation 5.54	20.8 mg/L Standard Deviation 8.40	—
Serum Concentration of REGN5713 Over the Study Duration Week 32	—	6.11 mg/L Standard Deviation 3.10	6.52 mg/L Standard Deviation 3.56	—
Serum Concentration of REGN5713 Over the Study Duration Week 36	—	2.88 mg/L Standard Deviation 1.47	4.18 mg/L Standard Deviation 3.02	—

SECONDARY outcome

Timeframe: Up to Week 36

Population: Randomized and treated participants who received REGN5714 and contributed to each timepoint

Outcome measures

Measure	REGN5713-5714-5715 900 mg 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo Matching placebo	Placebo n=54 Participants Matching placebo	Placebo Matching placebo
Serum Concentration of REGN5714 Over the Study Duration Baseline	—	—	0 mg/L Standard Deviation 0	—
Serum Concentration of REGN5714 Over the Study Duration Week 4	—	—	22.3 mg/L Standard Deviation 5.96	—
Serum Concentration of REGN5714 Over the Study Duration Week 8	—	—	13.1 mg/L Standard Deviation 4.36	—
Serum Concentration of REGN5714 Over the Study Duration Week 12	—	—	9.01 mg/L Standard Deviation 3.70	—
Serum Concentration of REGN5714 Over the Study Duration Week 18	—	—	5.34 mg/L Standard Deviation 3.69	—
Serum Concentration of REGN5714 Over the Study Duration Week 22	—	—	3.95 mg/L Standard Deviation 3.45	—
Serum Concentration of REGN5714 Over the Study Duration Week 27	—	—	29.0 mg/L Standard Deviation 9.51	—
Serum Concentration of REGN5714 Over the Study Duration Week 32	—	—	11.9 mg/L Standard Deviation 4.92	—
Serum Concentration of REGN5714 Over the Study Duration Week 36	—	—	7.90 mg/L Standard Deviation 4.10	—

SECONDARY outcome

Timeframe: Up to Week 36

Population: Randomized and treated participants who received REGN5715 and contributed to each timepoint

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=50 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=45 Participants Matching placebo	Placebo n=54 Participants Matching placebo	Placebo Matching placebo
Serum Concentration of REGN5715 Over the Study Duration Baseline	0 mg/L Standard Deviation 0	0 mg/L Standard Deviation 0	0 mg/L Standard Deviation 0	—
Serum Concentration of REGN5715 Over the Study Duration Week 4	20.6 mg/L Standard Deviation 5.94	21.5 mg/L Standard Deviation 5.54	26.7 mg/L Standard Deviation 9.37	—
Serum Concentration of REGN5715 Over the Study Duration Week 8	11.1 mg/L Standard Deviation 3.35	12.3 mg/L Standard Deviation 3.63	14.8 mg/L Standard Deviation 4.96	—
Serum Concentration of REGN5715 Over the Study Duration Week 12	8.30 mg/L Standard Deviation 3.42	8.73 mg/L Standard Deviation 3.38	10.4 mg/L Standard Deviation 4.28	—
Serum Concentration of REGN5715 Over the Study Duration Week 18	4.75 mg/L Standard Deviation 3.27	4.51 mg/L Standard Deviation 2.86	5.92 mg/L Standard Deviation 4.17	—
Serum Concentration of REGN5715 Over the Study Duration Week 22	3.02 mg/L Standard Deviation 2.20	3.12 mg/L Standard Deviation 2.16	4.29 mg/L Standard Deviation 3.77	—
Serum Concentration of REGN5715 Over the Study Duration Week 27	22.7 mg/L Standard Deviation 8.40	24.4 mg/L Standard Deviation 6.95	29.3 mg/L Standard Deviation 9.29	—
Serum Concentration of REGN5715 Over the Study Duration Week 32	9.60 mg/L Standard Deviation 4.09	10.7 mg/L Standard Deviation 4.26	12.2 mg/L Standard Deviation 4.93	—
Serum Concentration of REGN5715 Over the Study Duration Week 36	5.83 mg/L Standard Deviation 2.42	6.16 mg/L Standard Deviation 2.10	8.21 mg/L Standard Deviation 4.21	—

SECONDARY outcome

Timeframe: Up to Week 36

Population: Randomized and treated participants who received REGN5713 during the study

Outcome measures

Measure	REGN5713-5714-5715 900 mg 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=51 Participants Matching placebo	Placebo n=54 Participants Matching placebo	Placebo Matching placebo
Number of Participants With Anti-drug Antibodies (ADA) to REGN5713 Over Time Negative	—	51 Participants	54 Participants	—
Number of Participants With Anti-drug Antibodies (ADA) to REGN5713 Over Time Low Titer (<1000) Treatment Emergent Response	—	0 Participants	0 Participants	—
Number of Participants With Anti-drug Antibodies (ADA) to REGN5713 Over Time Moderate Titer (1000 to 10000) Treatment Emergent Response	—	0 Participants	0 Participants	—
Number of Participants With Anti-drug Antibodies (ADA) to REGN5713 Over Time High Titer (>10000) Treatment Emergent Response	—	0 Participants	0 Participants	—

SECONDARY outcome

Timeframe: Up to Week 36

Population: Randomized and treated participants who received REGN5714 during the study

Outcome measures

Measure	REGN5713-5714-5715 900 mg 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo Matching placebo	Placebo n=54 Participants Matching placebo	Placebo Matching placebo
Number of Participants With ADA to REGN5714 Over Time Negative	—	—	53 Participants	—
Number of Participants With ADA to REGN5714 Over Time Low Titer (<1000) Treatment Emergent Response	—	—	1 Participants	—
Number of Participants With ADA to REGN5714 Over Time Moderate Titer (1000 to 10000) Treatment Emergent Response	—	—	0 Participants	—
Number of Participants With ADA to REGN5714 Over Time High Titer (>10000) Treatment Emergent Response	—	—	0 Participants	—

SECONDARY outcome

Timeframe: Up to Week 36

Population: Randomized and treated participants who received REGN5715 during the study

Outcome measures

Measure	REGN5713-5714-5715 900 mg n=54 Participants 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)	Placebo n=51 Participants Matching placebo	Placebo n=54 Participants Matching placebo	Placebo Matching placebo
Number of Participants With ADA to REGN5715 Over Time Negative	53 Participants	50 Participants	53 Participants	—
Number of Participants With ADA to REGN5715 Over Time Low Titer (<1000) Treatment Emergent Response	1 Participants	1 Participants	1 Participants	—
Number of Participants With ADA to REGN5715 Over Time Moderate Titer (1000 to 10000) Treatment Emergent Response	0 Participants	0 Participants	0 Participants	—
Number of Participants With ADA to REGN5715 Over Time High Titer (>10000) Treatment Emergent Response	0 Participants	0 Participants	0 Participants	—

Adverse Events

Placebo

Serious events: 0 serious events

Other events: 23 other events

Deaths: 0 deaths

REGN5715 300 mg

Serious events: 0 serious events

Other events: 19 other events

Deaths: 0 deaths

REGN5713-5715 600 mg

Serious events: 0 serious events

Other events: 20 other events

Deaths: 0 deaths

REGN5713-5714-5715 900 mg

Serious events: 0 serious events

Other events: 19 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Measure	Placebo n=55 participants at risk Matching placebo	REGN5715 300 mg n=55 participants at risk 1-monoclonal antibody (mAb) REGN5715 300 mg plus placebo to replace REGN5713-5714	REGN5713-5715 600 mg n=51 participants at risk 2-monoclonal antibody (mAb) cocktail REGN5713-5715 600 mg (300 mg per mAb) plus placebo to replace REGN5714	REGN5713-5714-5715 900 mg n=55 participants at risk 3-monoclonal antibody (mAb) cocktail REGN5713-5714-5715 900 mg (300 mg per mAb)
Infections and infestations Upper respiratory tract infection	5.5% 3/55 • Number of events 3 • From the time of signing the informed consent form (ICF) up to Day 260	14.5% 8/55 • Number of events 8 • From the time of signing the informed consent form (ICF) up to Day 260	9.8% 5/51 • Number of events 7 • From the time of signing the informed consent form (ICF) up to Day 260	5.5% 3/55 • Number of events 5 • From the time of signing the informed consent form (ICF) up to Day 260
Infections and infestations COVID-19	7.3% 4/55 • Number of events 4 • From the time of signing the informed consent form (ICF) up to Day 260	5.5% 3/55 • Number of events 3 • From the time of signing the informed consent form (ICF) up to Day 260	9.8% 5/51 • Number of events 5 • From the time of signing the informed consent form (ICF) up to Day 260	3.6% 2/55 • Number of events 2 • From the time of signing the informed consent form (ICF) up to Day 260
Nervous system disorders Headache	14.5% 8/55 • Number of events 16 • From the time of signing the informed consent form (ICF) up to Day 260	7.3% 4/55 • Number of events 7 • From the time of signing the informed consent form (ICF) up to Day 260	19.6% 10/51 • Number of events 17 • From the time of signing the informed consent form (ICF) up to Day 260	12.7% 7/55 • Number of events 8 • From the time of signing the informed consent form (ICF) up to Day 260
Nervous system disorders Presyncope	5.5% 3/55 • Number of events 3 • From the time of signing the informed consent form (ICF) up to Day 260	5.5% 3/55 • Number of events 3 • From the time of signing the informed consent form (ICF) up to Day 260	3.9% 2/51 • Number of events 2 • From the time of signing the informed consent form (ICF) up to Day 260	3.6% 2/55 • Number of events 3 • From the time of signing the informed consent form (ICF) up to Day 260
Injury, poisoning and procedural complications Injection related reaction	0.00% 0/55 • From the time of signing the informed consent form (ICF) up to Day 260	7.3% 4/55 • Number of events 4 • From the time of signing the informed consent form (ICF) up to Day 260	2.0% 1/51 • Number of events 2 • From the time of signing the informed consent form (ICF) up to Day 260	0.00% 0/55 • From the time of signing the informed consent form (ICF) up to Day 260
Injury, poisoning and procedural complications Immunisation reaction	0.00% 0/55 • From the time of signing the informed consent form (ICF) up to Day 260	5.5% 3/55 • Number of events 3 • From the time of signing the informed consent form (ICF) up to Day 260	0.00% 0/51 • From the time of signing the informed consent form (ICF) up to Day 260	0.00% 0/55 • From the time of signing the informed consent form (ICF) up to Day 260
Musculoskeletal and connective tissue disorders Arthralgia	0.00% 0/55 • From the time of signing the informed consent form (ICF) up to Day 260	3.6% 2/55 • Number of events 2 • From the time of signing the informed consent form (ICF) up to Day 260	2.0% 1/51 • Number of events 1 • From the time of signing the informed consent form (ICF) up to Day 260	5.5% 3/55 • Number of events 4 • From the time of signing the informed consent form (ICF) up to Day 260
Musculoskeletal and connective tissue disorders Back pain	5.5% 3/55 • Number of events 4 • From the time of signing the informed consent form (ICF) up to Day 260	1.8% 1/55 • Number of events 1 • From the time of signing the informed consent form (ICF) up to Day 260	2.0% 1/51 • Number of events 1 • From the time of signing the informed consent form (ICF) up to Day 260	7.3% 4/55 • Number of events 7 • From the time of signing the informed consent form (ICF) up to Day 260
Respiratory, thoracic and mediastinal disorders Oropharyngeal pain	9.1% 5/55 • Number of events 6 • From the time of signing the informed consent form (ICF) up to Day 260	3.6% 2/55 • Number of events 2 • From the time of signing the informed consent form (ICF) up to Day 260	3.9% 2/51 • Number of events 2 • From the time of signing the informed consent form (ICF) up to Day 260	0.00% 0/55 • From the time of signing the informed consent form (ICF) up to Day 260
Respiratory, thoracic and mediastinal disorders Nasal congestion	3.6% 2/55 • Number of events 2 • From the time of signing the informed consent form (ICF) up to Day 260	0.00% 0/55 • From the time of signing the informed consent form (ICF) up to Day 260	0.00% 0/51 • From the time of signing the informed consent form (ICF) up to Day 260	5.5% 3/55 • Number of events 6 • From the time of signing the informed consent form (ICF) up to Day 260
Gastrointestinal disorders Nausea	7.3% 4/55 • Number of events 4 • From the time of signing the informed consent form (ICF) up to Day 260	1.8% 1/55 • Number of events 1 • From the time of signing the informed consent form (ICF) up to Day 260	0.00% 0/51 • From the time of signing the informed consent form (ICF) up to Day 260	1.8% 1/55 • Number of events 2 • From the time of signing the informed consent form (ICF) up to Day 260
General disorders Injection site erythema	3.6% 2/55 • Number of events 7 • From the time of signing the informed consent form (ICF) up to Day 260	1.8% 1/55 • Number of events 1 • From the time of signing the informed consent form (ICF) up to Day 260	7.8% 4/51 • Number of events 6 • From the time of signing the informed consent form (ICF) up to Day 260	3.6% 2/55 • Number of events 3 • From the time of signing the informed consent form (ICF) up to Day 260
General disorders Injection site pain	1.8% 1/55 • Number of events 1 • From the time of signing the informed consent form (ICF) up to Day 260	0.00% 0/55 • From the time of signing the informed consent form (ICF) up to Day 260	0.00% 0/51 • From the time of signing the informed consent form (ICF) up to Day 260	5.5% 3/55 • Number of events 4 • From the time of signing the informed consent form (ICF) up to Day 260
General disorders Injection site pruritus	5.5% 3/55 • Number of events 8 • From the time of signing the informed consent form (ICF) up to Day 260	0.00% 0/55 • From the time of signing the informed consent form (ICF) up to Day 260	5.9% 3/51 • Number of events 3 • From the time of signing the informed consent form (ICF) up to Day 260	1.8% 1/55 • Number of events 1 • From the time of signing the informed consent form (ICF) up to Day 260
Investigations Hepatic enzyme increased	5.5% 3/55 • Number of events 3 • From the time of signing the informed consent form (ICF) up to Day 260	0.00% 0/55 • From the time of signing the informed consent form (ICF) up to Day 260	2.0% 1/51 • Number of events 1 • From the time of signing the informed consent form (ICF) up to Day 260	1.8% 1/55 • Number of events 1 • From the time of signing the informed consent form (ICF) up to Day 260

Additional Information

Clinical Trials Administrator

Regeneron Pharmaceuticals, Inc.

Phone: 844-734-6643

Email: clinicaltrials@regeneron.com

Results disclosure agreements

• Principal investigator is a sponsor employee The investigator has the right to independently publish study results from the investigator's site after a multi-center publication, or a defined period after the completion of the study by all sites. The investigator must provide the Sponsor a copy of any such publication derived from the study for review and comment in advance of any submission, and delay publication, if requested, to allow the Sponsor to preserve its proprietary rights.
• Publication restrictions are in place

Restriction type: OTHER