Efficacy, Safety, and Pharmacokinetic Profiles of REGN3500 Administered to Adult Patients With Moderate-to-Severe Atopic Dermatitis

Percentage of Participants Who Achieved Eczema Area and Severity Index-50 (EASI-50) (Greater Than or Equal to [≥] 50 Percent [%] Improvement From Baseline) Based on Observed Values Set to Missing After Rescue Treatment at Week 16

The EASI score was used to measure the severity and extent of AD and measures erythema, infiltration, excoriation and lichenification on 4 anatomic regions of the body: head, trunk, upper and lower extremities. The total EASI score ranges from 0 (minimum) to 72 (maximum) points, with the higher scores reflecting the worse severity of AD. Percentage of participants who achieved EASI-50 (≥50% Improvement from baseline) at Week 16 were reported. Values after first rescue treatment were set to missing and participants with missing EASI score at Week 16 were counted as non-responders.

Time frame: Week 16

Percentage of Participants Who Achieved Eczema Area and Severity Index-50 (EASI-50) (Greater Than or Equal to [≥] 50% Improvement From Baseline) Based on All Observed Values Regardless of Rescue Treatment at Week 16

The EASI score was used to measure the severity and extent of AD and measures erythema, infiltration, excoriation and lichenification on 4 anatomic regions of the body: head, trunk, upper and lower extremities. The total EASI score ranges from 0 (minimum) to 72 (maximum) points, with the higher scores reflecting the worse severity of AD. Percentage of participants who achieved EASI-50 (≥50% Improvement from baseline) at Week 16 were based on all observed values regardless of rescue treatment were reported.

Time frame: Week 16

Percentage of Participants Who Achieved Eczema Area and Severity Index-75 (EASI-75) (≥75% Improvement From Baseline) Based on Observed Values Set to Missing After Rescue Treatment at Week 16

The EASI score was used to measure the severity and extent of AD and measures erythema, infiltration, excoriation and lichenification on 4 anatomic regions of the body: head, trunk, upper and lower extremities. The total EASI score ranges from 0 (minimum) to 72 (maximum) points, with the higher scores reflecting the worse severity of AD. Percentage of participants who achieved EASI-75 (≥75% Improvement from baseline) at Week 16 based on observed values set to missing after rescue treatment were reported. Values after first rescue treatment were set to missing and participants with missing EASI score at Week 16 were counted as non-responders.

Time frame: Week 16

Percentage of Participants Who Achieved Eczema Area and Severity Index-75 (EASI-75) (≥75% Improvement From Baseline) Based on All Observed Values Regardless of Rescue Treatment at Week 16

The EASI score was used to measure the severity and extent of AD and measures erythema, infiltration, excoriation and lichenification on 4 anatomic regions of the body: head, trunk, upper and lower extremities. The total EASI score ranges from 0 (minimum) to 72 (maximum) points, with the higher scores reflecting the worse severity of AD. Percentage of participants who achieved EASI-75 (≥75% Improvement from baseline) at Week 16 based on all observed values regardless of rescue treatment were reported.

Time frame: Week 16

Percentage of Participants Who Achieved Eczema Area and Severity Index-90 (EASI-90) (≥90% Improvement From Baseline) Based on Observed Values Set to Missing After Rescue Treatment at Week 16

The EASI score was used to measure the severity and extent of AD and measures erythema, infiltration, excoriation and lichenification on 4 anatomic regions of the body: head, trunk, upper and lower extremities. The total EASI score ranges from 0 (minimum) to 72 (maximum) points, with the higher scores reflecting the worse severity of AD. Percentage of participants who achieved EASI-90 (≥90% Improvement from baseline) at Week 16 based on observed values set to missing after rescue treatment were reported. Values after first rescue treatment were set to missing and participants with missing EASI score at Week 16 were counted as non-responders.

Time frame: Week 16

Percentage of Participants Who Achieved Eczema Area and Severity Index-90 (EASI-90) (≥90% Improvement From Baseline) Based on All Observed Values Regardless of Rescue Treatment at Week 16

The EASI score was used to measure the severity and extent of AD and measures erythema, infiltration, excoriation and lichenification on 4 anatomic regions of the body: head, trunk, upper and lower extremities. The total EASI score ranges from 0 (minimum) to 72 (maximum) points, with the higher scores reflecting the worse severity of AD. Percentage of participants who achieved EASI-90 (≥90% Improvement from baseline) at Week 16 based on all observed values regardless of rescue treatment were reported.

Time frame: Week 16

Absolute Change From Baseline in Eczema Area and Severity Index (EASI) Score Based on Observed Values Set to Missing After Rescue Treatment at Week 16

The EASI score was used to measure the severity and extent of AD and measures erythema, induration, excoriation and lichenification on 4 anatomic regions of the body: head, trunk, upper and lower extremities. The total EASI score ranges from 0 (minimum) to 72 (maximum) points, with the higher scores reflecting the worse severity of AD. Absolute change from baseline in EASI score at Week 16 based on observed values set to missing after rescue treatment was reported.

Time frame: Week 16

Absolute Change From Baseline in Eczema Area and Severity Index (EASI) Score Based on All Observed Values Regardless of Rescue Treatment at Week 16

The EASI score was used to measure the severity and extent of AD and measures erythema, induration, excoriation and lichenification on 4 anatomic regions of the body: head, trunk, upper and lower extremities. The total EASI score ranges from 0 (minimum) to 72 (maximum) points, with the higher scores reflecting the worse severity of AD. Absolute change from baseline in EASI score at Week 16 based on all observed values regardless of rescue treatment was reported.

Time frame: Week 16

Percentage of Participants With Both Investigator Global Assessment (IGA) Score 0 or 1 (on 0 to 5 IGA Scale) and a Reduction From Baseline of ≥2 Points Based on Observed Values Set to Missing After Rescue Treatment at Week 16

IGA was an assessment scale used to determine severity of AD and clinical response to treatment on a 5 point scale (0 = clear; 1 = almost clear; 2 = mild; 3 = moderate; 4 = severe) based on erythema and papulation/infiltration. Therapeutic response was an IGA score of 0 (clear) or 1 (almost clear). Participants with both IGA score of "0" or "1" and a reduction from baseline of ≥2 points at Week 16 based on observed values set to missing after rescue treatment were reported. Values after first rescue treatment were set to missing and participants with missing IGA score at Week 16 were counted as non-responders.

Time frame: Week 16

Percentage of Participants With Both IGA Score 0 or 1 (on the 0 to 5 IGA Scale) and a Reduction From Baseline of ≥2 Points Based on All Observed Values Regardless of Rescue Treatment at Week 16

IGA was an assessment scale used to determine severity of AD and clinical response to treatment on a 5 point scale (0 = clear; 1 = almost clear; 2 = mild; 3 = moderate; 4 = severe) based on erythema and papulation/infiltration. Therapeutic response was an IGA score of 0 (clear) or 1 (almost clear). Participants with both IGA score of "0" or "1" and a reduction from baseline of ≥2 points at Week 16 based on all observed values regardless of rescue treatment were reported.

Time frame: Week 16

Absolute Change From Baseline in Weekly Average of Daily Peak Pruritus Numerical Rating Scale (NRS) Score Based on Observed Values Set to Missing After Rescue Treatment at Week 16

Pruritus NRS was an assessment tool used to report the intensity of a participant's pruritus (itch), both maximum and average intensity, using an electronic questionnaire (e-diary). Participants were asked the following question: how would you rate your itch at the worst moment during the previous 24 hours (for maximum itch intensity on a scale of 0 - 10 \[0 = no itch; 10 = worst itch imaginable\]). Absolute change from baseline in weekly average of daily Peak Pruritus NRS score at Week 16 based on observed values set to missing after rescue treatment was reported.

Time frame: Week 16

Absolute Change From Baseline in Weekly Average of Daily Peak Pruritus NRS Score Based on All Observed Values Regardless of Rescue Treatment at Week 16

Pruritus NRS was an assessment tool used to report the intensity of a participant's pruritus (itch), both maximum and average intensity, using an electronic questionnaire (e-diary). Participants were asked the following question: how would you rate your itch at the worst moment during the previous 24 hours (for maximum itch intensity on a scale of 0 - 10 \[0 = no itch; 10 = worst itch imaginable\]). Absolute Change From Baseline in Weekly Average of Daily Peak Pruritus NRS Score Based on All Observed Values Regardless of Rescue Treatment at Week 16

Time frame: Week 16

Percent Change From Baseline in Weekly Average of Daily Peak Pruritus NRS Score Based on Observed Values Set to Missing After Rescue Treatment at Week 16

Pruritus NRS was an assessment tool used to report the intensity of a participant's pruritus (itch), both maximum and average intensity, using an electronic questionnaire (e-diary). Participants were asked the following question: how would you rate your itch at the worst moment during the previous 24 hours (for maximum itch intensity on a scale of 0 - 10 \[0 = no itch; 10 = worst itch imaginable\]). Percent change from baseline in weekly average of daily peak pruritus NRS score at Week 16 based on observed values set to missing after rescue treatment was reported. Values after first rescue treatment were set to missing and participants with missing NRS score at Week 16 were counted as non-responders.

Time frame: Week 16

Percent Change From Baseline in Weekly Average of Daily Peak Pruritus NRS Score Based on All Observed Values Regardless of Rescue Treatment at Week 16

Pruritus NRS was an assessment tool used to report the intensity of a participant's pruritus (itch), both maximum and average intensity, using an electronic questionnaire (e-diary). Participants were asked the following question: how would you rate your itch at the worst moment during the previous 24 hours (for maximum itch intensity on a scale of 0 - 10 \[0 = no itch; 10 = worst itch imaginable\]). Percent change from baseline in weekly average of daily peak pruritus NRS score at Week 16 based on all observed values regardless of rescue treatment was reported.

Time frame: Week 16

Percentage of Participants With Improvement (Reduction From Baseline) in Weekly Average of Peak Daily Pruritus NRS Score ≥4 Based on Observed Values Set to Missing After Rescue Treatment at Week 16

Pruritus NRS was an assessment tool used to report the intensity of a participant's pruritus (itch), both maximum and average intensity, using an electronic questionnaire (e-diary). Participants were asked the following question: how would you rate your itch at the worst moment during the previous 24 hours (for maximum itch intensity on a scale of 0 - 10 \[0 = no itch; 10 = worst itch imaginable\]). Percentage of participants with improvement of weekly average of daily peak pruritus NRS score ≥4 from baseline to Week 16 based on observed values set to missing after rescue treatment were reported. Values after first rescue treatment were set to missing and participants with missing NRS score at Week 16 were counted as non-responders.

Time frame: Week 16

Percentage of Participants With Improvement (Reduction From Baseline) in Weekly Average of Daily Peak Pruritus NRS Score ≥4 Based on All Observed Values Regardless of Rescue Treatment at Week 16

Pruritus NRS was an assessment tool used to report the intensity of a participant's pruritus (itch), both maximum and average intensity, using an electronic questionnaire (e-diary). Participants were asked the following question: how would you rate your itch at the worst moment during the previous 24 hours (for maximum itch intensity on a scale of 0 - 10 \[0 = no itch; 10 = worst itch imaginable\]). Percentage of participants with improvement of weekly average of daily peak pruritus NRS score ≥4 from baseline to Week 16 based on all observed values regardless of rescue treatment were reported.

Time frame: Week 16

Time to Onset of Effect on Pruritus (≥4-point Reduction of Weekly Average of Daily Peak Pruritus NRS From Baseline)

Peak Pruritus NRS is an assessment tool used by participants to report intensity of pruritus (itch) during a 24-hour recall period. Participants were asked the following question: For maximum itch intensity: "On a scale of 0 to 10, with 0 being 'no itch' and 10 being the 'worst itch imaginable,' how would you rate your itch at the worst moment during the previous 24 hours?"

Time frame: Week 16

Percent Change From Baseline in SCORing Atopic Dermatitis (SCORAD) at Week 16

The SCORAD index is a clinical tool for assessing the severity of atopic dermatitis (AD). Extent and intensity of eczema as well as subjective signs (insomnia, etc.) are assessed and scored. Total score ranges from 0 (absent disease) to 103 (severe disease).

Time frame: Week 16

Absolute Change From Baseline in Percent Body Surface Area (BSA) of Atopic Dermatitis (AD) Involvement at Week 16

BSA affected by AD will be assessed for each section of the body using the rule of nines (the possible highest score for each region is: head and neck \[9%\], anterior trunk \[18%\], back \[18%\], upper limbs \[18%\], lower limbs \[36%\], and genitals \[1%\]) and will be reported as a percentage of all major body sections combined. The proportion assigned to different body regions is different in younger children as compared to older children (head and neck area is assigned a higher proportion in younger children as compared to older children).

Time frame: Week 16

Number of Participants With Treatment-Emergent Adverse Events (TEAEs), Serious TEAEs and Adverse Events of Special Interest (AESIs) up to Week 16

Adverse Event (AE): any untoward medical occurrence in a participant administered a study drug which may/may not have a causal relationship with study drug. Serious AE (SAE): any untoward medical occurrence that resulted in any of following outcomes: death, life-threatening, required initial/prolonged in-participant hospitalization, persistent/significant disability/incapacity, congenital anomaly/birth defect/considered as medically important event. TEAE: AEs starting/worsening after first intake of study drug. TEAEs included: serious TEAEs and Non-serious TEAEs. AESI included: Anaphylactic or acute allergic reactions; Severe injection site reactions; Mycosis fungoides/other forms of cutaneous T-cell lymphoma; severe infections; any clinical endoparasitosis; Conjunctivitis, keratitis, or blepharitis; significant Alanine aminotransferase (ALT) elevation. Number of participants with TEAEs, Serious TEAES and AESIs from baseline up to Week 16 were reported.

Time frame: Up to week 16

Number of Participants With Treatment-Emergent Adverse Events (TEAEs), Serious TEAEs and Adverse Events of Special Interest (AESIs) up to Week 36

AE: any untoward medical occurrence in a participant administered a study drug which may/may not have a causal relationship with study drug. SAE: any untoward medical occurrence that resulted in any of following outcomes: death, life-threatening, required initial/prolonged in-participant hospitalization, persistent/significant disability/incapacity, congenital anomaly/birth defect/considered as medically important event. TEAE: AEs starting/worsening after first intake of study drug. TEAEs included both Serious TEAEs and Non-serious TEAEs. AESI included: Anaphylactic or acute allergic reactions; Severe injection site reactions; Mycosis fungoides/other forms of cutaneous T-cell lymphoma; severe infections; any clinical endoparasitosis; Conjunctivitis, keratitis, or blepharitis; significant Alanine aminotransferase (ALT) elevation. Number of participants with TEAEs, Serious TEAES and AESIs from baseline up to Week 36 were reported.

Time frame: Up to week 36

Serum Concentration of Functional REGN3500

Serum Concentration of Functional REGN3500 was reported.

Time frame: Baseline (Week 0), Weeks 2, 4, 8, 12, 16, 20, 24, 28, 32 and 36

Number of Participants With Positive Treatment-Emergent Anti-REGN3500 Antibodies (ADA)

Treatment-Emergent (TE) ADA was defined as any positive post baseline assay response when baseline results were negative or missing. Treatment-Emergent ADA responses were further classified as: - persistent (treatment-emergent positive ADA response detected in at least 2 consecutive post baseline samples separated by at least a 16-week post baseline period \[based on nominal sampling time\], with no ADA-negative samples in-between, regardless of any missing samples or a positive response at the last ADA sampling time point),- indeterminate (a positive assay response at the last collection time point only, regardless of any missing samples), - transient (not persistent/indeterminate, regardless of any missing samples). Number of participants with positive treatment-emergent anti-REGN3500 antibodies (ADA) were reported. Here, "Number of Participants Analyzed" signifies those participants who were evaluable for this endpoint.

Time frame: Up to week 36