A Study to Evaluate the Efficacy and Safety of Dupilumab in Adult Patients With Bullous Pemphigoid

Total Cumulative Dose of Oral Corticosteroids (OCS) From Baseline to Week 36

All participants in both treatment groups were started on OCS at randomization (day 1) with taper beginning no later than week 6 with the objective to taper off by week 16. OCS could be used as rescue treatment for loss of disease control/ disease relapse during the study. Days after non-OCS systemic rescue treatment use were imputed by the worst observation carried forward (WOCF) method (i.e., the highest daily OCS dose prior to any non-OCS systemic rescue treatment use). Missing data after study discontinuation were imputed with the average daily OCS dose among week 36 completers in each treatment group.

Time frame: Week 36

Percent Change in Weekly Average of Daily Peak Pruritus Numerical Rating Scale (NRS) Score From Baseline to Week 36

Peak pruritus NRS was used by participants to rate the intensity of pruritus during the past 24 hours, with 0 indicating no itch and 10 indicating worst itch possible. Participants were required to have a baseline peak pruritus NRS maximum intensity average of ≥4 during the 7 days prior to randomization for eligibility. Values after first rescue treatment were set to missing and were imputed with the worst value from the closest visit on or prior to rescue medication use and afterwards up to and including week 36. Missing values caused by discontinuation from the study due to lack of efficacy, treatment-related AE, or death were imputed by the WOCF method. Missing values due to other reasons were imputed by multiple imputation.

Time frame: Baseline, Week 36

Percent of Participants With Improvement (Reduction) of Weekly Average of Daily Peak Pruritus NRS ≥4 From Baseline to Week 36

Peak pruritus NRS was used by participants to rate the intensity of pruritus during the past 24 hours, with 0 indicating no itch and 10 indicating worst itch possible. Participants were required to have a baseline peak pruritus NRS maximum intensity average of ≥4 during the 7 days prior to randomization for eligibility. Participants were considered non-responders after rescue treatment use. Participants with missing values caused by discontinuation from the study before week 36 due to lack of efficacy, treatment-related AE, or death were considered non-responders. Missing values due to other reasons were imputed using multiple imputation of the continuous data of the weekly average of daily peak pruritus NRS.

Time frame: Baseline, Week 36

Percent Change in Bullous Pemphigoid Disease Area Index (BPDAI) Activity Score From Baseline to Week 36

BPDAI activity score is the arithmetic sum of 3 subcomponents: cutaneous blisters/erosions, cutaneous urticaria/erythema, and mucosal blisters/erosions. Scores can range from 0 to 360 for BPDAI total activity (maximum 240 for total skin activity and 120 for mucosal activity), with higher scores indicating greater disease activity. Participants were required to have a BPDAI activity score of ≥24 at the screening and baseline visits for eligibility. Values after first rescue treatment were set to missing and were imputed with the worst value from the closest visit on or prior to rescue medication use and afterwards up to and including week 36. Missing values caused by discontinuation from the study due to lack of efficacy, treatment-related AE, or death were imputed by the WOCF method. Missing values due to other reasons were imputed by multiple imputation.

Time frame: Baseline, Week 36

Time to First Use of Rescue Medication Up to Week 36

Participants were considered to have used rescue treatment at the time of discontinuation from the study due to lack of efficacy, treatment-related AE, or death. Participants were censored at the time of discontinuation from the study due to other reasons. Restricted mean event time and corresponding standard error (SE) are based on the Kaplan-Meier method. The restricted mean event time was calculated up to study day 253 (i.e., week 36).

Time frame: Up to Week 36

Duration of Complete Remission While Not Requiring OCS Up to Week 36

Complete remission was defined as absence of new lesions and epithelialization of old lesions. Participants were considered as not achieving complete remission after rescue treatment use. Participants with missing assessment of complete remission caused by discontinuation from the study before week 36 due to lack of efficacy, treatment-related AE, or death were considered as not achieving complete remission. Participants with missing assessment of complete remission due to other reasons were imputed using multiple imputation.

Time frame: Up to Week 36

Percent of Participants Who Did Not Achieve Control of Disease Activity Before Week 36

Control of disease activity was defined as absence of new lesions and existing lesions beginning to heal. Participants who achieved initial control of disease activity after rescue treatment use were considered to not have achieved control of disease activity before week 36. Participants whose response status could not be determined due to missing data were considered to not have achieved control of disease activity before week 36.

Time frame: Up to Week 36

Percent of Participants Who Relapsed After Achieving Control of Disease Activity Up to Week 36

Relapse was defined as the appearance of 3 or more new lesions a month (blisters, eczematous lesions, or urticarial plaques) or at least 1 large (\>10 centimeters \[cm\] diameter) eczematous lesion or urticarial plaque that does not heal within 1 week. Control of disease activity was defined as absence of new lesions and existing lesions beginning to heal. Participants who used rescue treatment were considered to have relapsed after achieving control of disease activity. Participants whose response status could not be determined due to missing data were considered to have relapsed after achieving control of disease activity.

Time frame: Up to Week 36

Percent of Participants Who Did Not Achieve Complete Remission Before Week 36

Complete remission was defined as absence of new lesions and epithelialization of old lesions. Participants who achieved initial complete remission after rescue treatment use were considered to not have achieved complete remission before week 36. Participants whose response status could not be determined due to missing data were considered to not have achieved complete remission before week 36.

Time frame: Up to Week 36

Percent of Participants Achieving a Reduction in BPDAI Activity Score of ≥50% From Baseline to Week 36

BPDAI activity score is the arithmetic sum of 3 subcomponents: cutaneous blisters/erosions, cutaneous urticaria/erythema, and mucosal blisters/erosions. Scores can range from 0 to 360 for BPDAI total activity (maximum 240 for total skin activity and 120 for mucosal activity), with higher scores indicating greater disease activity. Participants were required to have a BPDAI activity score of ≥24 at the screening and baseline visits for eligibility. Participants were considered non-responders after rescue treatment use. Participants with missing values caused by discontinuation from the study before week 36 due to lack of efficacy, treatment-related AE, or death were considered non-responders. Missing values due to other reasons were imputed using multiple imputation of the continuous data of the BPDAI activity score.

Time frame: Baseline, Week 36

Percent of Participants Achieving a Reduction in BPDAI Activity Score of ≥75% From Baseline to Week 36

BPDAI activity score is the arithmetic sum of 3 subcomponents: cutaneous blisters/erosions, cutaneous urticaria/erythema, and mucosal blisters/erosions. Scores can range from 0 to 360 for BPDAI total activity (maximum 240 for total skin activity and 120 for mucosal activity), with higher scores indicating greater disease activity. Participants were required to have a BPDAI activity score of ≥24 at the screening and baseline visits for eligibility. Participants were considered non-responders after rescue treatment use. Participants with missing values caused by discontinuation from the study before week 36 due to lack of efficacy, treatment-related AE, or death were considered non-responders. Missing values due to other reasons were imputed using multiple imputation of the continuous data of the BPDAI activity score.

Time frame: Baseline, Week 36

Percent of Participants Achieving a Reduction in BPDAI Activity Score of ≥90% From Baseline to Week 36

BPDAI activity score is the arithmetic sum of 3 subcomponents: cutaneous blisters/erosions, cutaneous urticaria/erythema, and mucosal blisters/erosions. Scores can range from 0 to 360 for BPDAI total activity (maximum 240 for total skin activity and 120 for mucosal activity), with higher scores indicating greater disease activity. Participants were required to have a BPDAI activity score of ≥24 at the screening and baseline visits for eligibility. Participants were considered non-responders after rescue treatment use. Participants with missing values caused by discontinuation from the study before week 36 due to lack of efficacy, treatment-related AE, or death were considered non-responders. Missing values due to other reasons were imputed using multiple imputation of the continuous data of the BPDAI activity score.

Time frame: Baseline, Week 36

Change in Autoimmune Bullous Disease Quality of Life (ABQOL) Score From Baseline to Week 36

ABQOL questionnaire consists of 17 items, which encompass physical burden of the disease, psychiatric effects, and effects on daily life functioning. Each question ranges from 0 to 3 points, with higher scores indicating poorer quality of life. The maximum ABQOL score is 51. Values after first rescue treatment were set to missing and were imputed with the worst value from the closest visit on or prior to rescue medication use and afterwards up to and including week 36. Missing values caused by discontinuation from the study due to lack of efficacy, treatment-related AE, or death were imputed by the WOCF method. Missing values due to other reasons were imputed by multiple imputation.

Time frame: Baseline, Week 36

Change in Percent Body Surface Area (BSA) of BP Involvement From Baseline to Week 36

Values after first rescue treatment were set to missing and were imputed with the worst value from the closest visit on or prior to rescue medication use and afterwards up to and including week 36. Missing values caused by discontinuation from the study due to lack of efficacy, treatment-related AE, or death were imputed by the WOCF method. Missing values due to other reasons were imputed by multiple imputation.

Time frame: Baseline, Week 36

Change in BP180 Immunoglobulin G (IgG) Autoantibody Titer From Baseline to Week 36

Values after first rescue treatment were set to missing and were imputed with the worst value from the closest visit on or prior to rescue medication use and afterwards up to and including week 36. Missing values caused by discontinuation from the study due to lack of efficacy, treatment-related AE, or death were imputed by the WOCF method. Missing values due to other reasons were imputed by multiple imputation.

Time frame: Baseline, Week 36

Change in BP230 IgG Autoantibody Titer From Baseline to Week 36

Values after first rescue treatment were set to missing and were imputed with the worst value from the closest visit on or prior to rescue medication use and afterwards up to and including week 36. Missing values caused by discontinuation from the study due to lack of efficacy, treatment-related AE, or death were imputed by the WOCF method. Missing values due to other reasons were imputed by multiple imputation.

Time frame: Baseline, Week 36

Percent of Participants Achieving Sustained Remission at Week 52

Sustained remission at week 52, defined as: (1) Complete remission (absence of new lesions \& epithelialization of old lesions) \& off OCS no later than week 16 \& (2) Absence of disease relapse (appearance of ≥3 new lesions a month \[blisters, eczematous lesions, or urticarial plaques\] or at least 1 large eczematous lesion or urticarial plaque that does not heal within 1 week) after completion of OCS taper, no later than week 16, to week 52 \& (3) Absence of need for rescue therapy during 52 weeks (rescue therapy includes increase of OCS dose during the taper, re-initiation of OCS after completion of the OCS taper, or initiation of any BP-directed therapy). Participants with missing sustained remission data at week 52 due to discontinuation due to lack of efficacy, treatment-related AE, or death were considered non-responders \& those with missing data due to other reasons were handled using multiple imputation.

Time frame: At Week 52

Total Cumulative Dose of OCS From Baseline to Week 52

All participants in both treatment groups were started on OCS at randomization (day 1) with taper beginning no later than week 6 with the objective to taper off by week 16. OCS could be used as rescue treatment for loss of disease control/ disease relapse during the study. Days after non-OCS systemic rescue treatment use were imputed by the WOCF method (i.e., the highest daily OCS dose prior to any non-OCS systemic rescue treatment use). Missing data after study discontinuation were imputed with the average daily OCS dose among week 52 completers in each treatment group.

Time frame: Week 52

Duration of Complete Remission While Not Requiring OCS Up to Week 52

Complete remission was defined as absence of new lesions and epithelialization of old lesions. Participants were considered as not achieving complete remission after rescue treatment use. Participants with missing assessment of complete remission caused by discontinuation from the study before week 52 due to lack of efficacy, treatment-related AE, or death were considered as not achieving complete remission. Participants with missing assessment of complete remission due to other reasons were imputed using multiple imputation.

Time frame: Up to Week 52

Percent of Participants Who Did Not Achieve Control of Disease Activity Before Week 52

Control of disease activity was defined as absence of new lesions and existing lesions beginning to heal. Participants who achieved initial control of disease activity after rescue treatment use were considered to not have achieved control of disease activity before week 52. Participants whose response status could not be determined due to missing data were considered to not have achieved control of disease activity before week 52.

Time frame: Up to Week 52

Percent of Participants Who Relapsed After Achieving Control of Disease Activity Up to Week 52

Relapse was defined as the appearance of 3 or more new lesions a month (blisters, eczematous lesions, or urticarial plaques) or at least 1 large (\>10 cm diameter) eczematous lesion or urticarial plaque that does not heal within 1 week. Control of disease activity was defined as absence of new lesions and existing lesions beginning to heal. Participants who used rescue treatment were considered to have relapsed after achieving control of disease activity. Participants whose response status could not be determined due to missing data were considered to have relapsed after achieving control of disease activity.

Time frame: Up to Week 52

Percent of Participants Who Did Not Achieve Complete Remission Before Week 52

Complete remission was defined as absence of new lesions and epithelialization of old lesions. Participants who achieved initial complete remission after rescue treatment use were considered to not have achieved complete remission before week 52. Participants whose response status could not be determined due to missing data were considered to not have achieved complete remission before week 52.

Time frame: Up to Week 52

Percent Change in Weekly Average of Daily Peak Pruritus NRS From Baseline to Week 52

Peak pruritus NRS was used by participants to rate the intensity of pruritus during the past 24 hours, with 0 indicating no itch and 10 indicating worst itch possible. Participants were required to have a baseline peak pruritus NRS maximum intensity average of ≥4 during the 7 days prior to randomization for eligibility. Values after first rescue treatment were set to missing and were imputed with the worst value from the closest visit on or prior to rescue medication use and afterwards up to and including week 52. Missing values caused by discontinuation from the study due to lack of efficacy, treatment-related AE, or death were imputed by the WOCF method. Missing values due to other reasons were imputed by multiple imputation.

Time frame: Baseline, Week 52

Percent of Participants With Improvement (Reduction) of Weekly Average of Daily Peak Pruritus NRS ≥4 From Baseline to Week 52

Peak pruritus NRS was used by participants to rate the intensity of pruritus during the past 24 hours, with 0 indicating no itch and 10 indicating worst itch possible. Participants were required to have a baseline peak pruritus NRS maximum intensity average of ≥4 during the 7 days prior to randomization for eligibility. Participants were considered non-responders after rescue treatment use. Participants with missing values caused by discontinuation from the study before week 52 due to lack of efficacy, treatment-related AE, or death were considered non-responders. Missing values due to other reasons were imputed using multiple imputation of the continuous data of the weekly average of daily peak pruritus NRS.

Time frame: Baseline, Week 52

Percent Change in BPDAI Activity Score From Baseline to Week 52

BPDAI activity score is the arithmetic sum of 3 subcomponents: cutaneous blisters/erosions, cutaneous urticaria/erythema, and mucosal blisters/erosions. Scores can range from 0 to 360 for BPDAI total activity (maximum 240 for total skin activity and 120 for mucosal activity), with higher scores indicating greater disease activity. Participants were required to have a BPDAI activity score of ≥24 at the screening and baseline visits for eligibility. Values after first rescue treatment were set to missing and were imputed with the worst value from the closest visit on or prior to rescue medication use and afterwards up to and including week 52. Missing values caused by discontinuation from the study due to lack of efficacy, treatment-related AE, or death were imputed by the WOCF method. Missing values due to other reasons were imputed by multiple imputation.

Time frame: Baseline, Week 52

Percent of Participants Achieving a Reduction in BPDAI Activity Score of ≥50% From Baseline to Week 52

BPDAI activity score is the arithmetic sum of 3 subcomponents: cutaneous blisters/erosions, cutaneous urticaria/erythema, and mucosal blisters/erosions. Scores can range from 0 to 360 for BPDAI total activity (maximum 240 for total skin activity and 120 for mucosal activity), with higher scores indicating greater disease activity. Participants were required to have a BPDAI activity score of ≥24 at the screening and baseline visits for eligibility. Participants were considered non-responders after rescue treatment use. Participants with missing values caused by discontinuation from the study before week 52 due to lack of efficacy, treatment-related AE, or death were considered non-responders. Missing values due to other reasons were imputed using multiple imputation of the continuous data of the BPDAI activity score.

Time frame: Baseline, Week 52

Percent of Participants Achieving a Reduction in BPDAI Activity Score of ≥75% From Baseline to Week 52

BPDAI activity score is the arithmetic sum of 3 subcomponents: cutaneous blisters/erosions, cutaneous urticaria/erythema, and mucosal blisters/erosions. Scores can range from 0 to 360 for BPDAI total activity (maximum 240 for total skin activity and 120 for mucosal activity), with higher scores indicating greater disease activity. Participants were required to have a BPDAI activity score of ≥24 at the screening and baseline visits for eligibility. Participants were considered non-responders after rescue treatment use. Participants with missing values caused by discontinuation from the study before week 52 due to lack of efficacy, treatment-related AE, or death were considered non-responders. Missing values due to other reasons were imputed using multiple imputation of the continuous data of the BPDAI activity score.

Time frame: Baseline, Week 52

Percent of Participants Achieving a Reduction in BPDAI Activity Score of ≥90% From Baseline to Week 52

BPDAI activity score is the arithmetic sum of 3 subcomponents: cutaneous blisters/erosions, cutaneous urticaria/erythema, and mucosal blisters/erosions. Scores can range from 0 to 360 for BPDAI total activity (maximum 240 for total skin activity and 120 for mucosal activity), with higher scores indicating greater disease activity. Participants were required to have a BPDAI activity score of ≥24 at the screening and baseline visits for eligibility. Participants were considered non-responders after rescue treatment use. Participants with missing values caused by discontinuation from the study before week 52 due to lack of efficacy, treatment-related AE, or death were considered non-responders. Missing values due to other reasons were imputed using multiple imputation of the continuous data of the BPDAI activity score.

Time frame: Baseline, Week 52

Change in ABQOL Score From Baseline to Week 52

ABQOL questionnaire consists of 17 items, which encompass physical burden of the disease, psychiatric effects, and effects on daily life functioning. Each question ranges from 0 to 3 points, with higher scores indicating poorer quality of life. The maximum ABQOL score is 51. Values after first rescue treatment were set to missing and were imputed with the worst value from the closest visit on or prior to rescue medication use and afterwards up to and including week 52. Missing values caused by discontinuation from the study due to lack of efficacy, treatment-related AE, or death were imputed by the WOCF method. Missing values due to other reasons were imputed by multiple imputation.

Time frame: Baseline, Week 52

Change in Percent BSA of BP Involvement From Baseline to Week 52

Values after first rescue treatment were set to missing and were imputed with the worst value from the closest visit on or prior to rescue medication use and afterwards up to and including week 52. Missing values caused by discontinuation from the study due to lack of efficacy, treatment-related AE, or death were imputed by the WOCF method. Missing values due to other reasons were imputed by multiple imputation.

Time frame: Baseline, Week 52

Change in BP180 IgG Autoantibody Titer From Baseline to Week 52

Values after first rescue treatment were set to missing and were imputed with the worst value from the closest visit on or prior to rescue medication use and afterwards up to and including week 52. Missing values caused by discontinuation from the study due to lack of efficacy, treatment-related AE, or death were imputed by the WOCF method. Missing values due to other reasons were imputed by multiple imputation.

Time frame: Baseline, Week 52

Change in BP230 IgG Autoantibody Titer From Baseline to Week 52

Values after first rescue treatment were set to missing and were imputed with the worst value from the closest visit on or prior to rescue medication use and afterwards up to and including week 52. Missing values caused by discontinuation from the study due to lack of efficacy, treatment-related AE, or death were imputed by the WOCF method. Missing values due to other reasons were imputed by multiple imputation.

Time frame: Baseline, Week 52

Percent of Participants in Complete Remission and Off OCS No Later Than Week 16

Complete remission was defined as absence of new lesions and epithelialization of old lesions. Participants were considered non-responders after rescue treatment use. Participants with missing assessment of complete remission caused by discontinuation from the study before week 16 due to lack of efficacy, treatment-related AE, or death were considered non-responders. Participants with missing assessment of complete remission before week 16 due to other reasons were imputed using multiple imputation.

Time frame: Up to Week 16

Percent Change in BPDAI Activity Score From Baseline to Week 16

BPDAI activity score is the arithmetic sum of 3 subcomponents: cutaneous blisters/erosions, cutaneous urticaria/erythema, and mucosal blisters/erosions. Scores can range from 0 to 360 for BPDAI total activity (maximum 240 for total skin activity and 120 for mucosal activity), with higher scores indicating greater disease activity. Participants were required to have a BPDAI activity score of ≥24 at the screening and baseline visits for eligibility. Values after first rescue treatment were set to missing and were imputed with the worst value from the closest visit on or prior to rescue medication use and afterwards up to and including week 36. Missing values caused by discontinuation from the study due to lack of efficacy, treatment-related AE, or death were imputed by the WOCF method. Missing values due to other reasons were imputed by multiple imputation.

Time frame: Baseline, Week 16

Percent of Participants Achieving a Reduction in BPDAI Activity Score of ≥50% From Baseline to Week 16

BPDAI activity score is the arithmetic sum of 3 subcomponents: cutaneous blisters/erosions, cutaneous urticaria/erythema, and mucosal blisters/erosions. Scores can range from 0 to 360 for BPDAI total activity (maximum 240 for total skin activity and 120 for mucosal activity), with higher scores indicating greater disease activity. Participants were required to have a BPDAI activity score of ≥24 at the screening and baseline visits for eligibility. Participants were considered non-responders after rescue treatment use. Participants with missing values caused by discontinuation from the study before week 16 due to lack of efficacy, treatment-related AE, or death were considered non-responders. Missing values due to other reasons were imputed using multiple imputation of the continuous data of the BPDAI activity score.

Time frame: Baseline, Week 16

Percent of Participants Achieving a Reduction in BPDAI Activity Score of ≥75% From Baseline to Week 16

BPDAI activity score is the arithmetic sum of 3 subcomponents: cutaneous blisters/erosions, cutaneous urticaria/erythema, and mucosal blisters/erosions. Scores can range from 0 to 360 for BPDAI total activity (maximum 240 for total skin activity and 120 for mucosal activity), with higher scores indicating greater disease activity. Participants were required to have a BPDAI activity score of ≥24 at the screening and baseline visits for eligibility. Participants were considered non-responders after rescue treatment use. Participants with missing values caused by discontinuation from the study before week 16 due to lack of efficacy, treatment-related AE, or death were considered non-responders. Missing values due to other reasons were imputed using multiple imputation of the continuous data of the BPDAI activity score.

Time frame: Baseline, Week 16

Percent of Participants Achieving a Reduction in BPDAI Activity Score of ≥90% From Baseline to Week 16

BPDAI activity score is the arithmetic sum of 3 subcomponents: cutaneous blisters/erosions, cutaneous urticaria/erythema, and mucosal blisters/erosions. Scores can range from 0 to 360 for BPDAI total activity (maximum 240 for total skin activity and 120 for mucosal activity), with higher scores indicating greater disease activity. Participants were required to have a BPDAI activity score of ≥24 at the screening and baseline visits for eligibility. Participants were considered non-responders after rescue treatment use. Participants with missing values caused by discontinuation from the study before week 16 due to lack of efficacy, treatment-related AE, or death were considered non-responders. Missing values due to other reasons were imputed using multiple imputation of the continuous data of the BPDAI activity score.

Time frame: Baseline, Week 16

Percent Change in Weekly Average of Daily Peak Pruritus NRS From Baseline to Week 16

Peak pruritus NRS was used by participants to rate the intensity of pruritus during the past 24 hours, with 0 indicating no itch and 10 indicating worst itch possible. Participants were required to have a baseline peak pruritus NRS maximum intensity average of ≥4 during the 7 days prior to randomization for eligibility. Values after first rescue treatment were set to missing and were imputed with the worst value from the closest visit on or prior to rescue medication use and afterwards up to and including week 36. Missing values caused by discontinuation from the study due to lack of efficacy, treatment-related AE, or death were imputed by the WOCF method. Missing values due to other reasons were imputed by multiple imputation.

Time frame: Baseline, Week 16

Percent of Participants With Improvement (Reduction) of Weekly Average of Daily Peak Pruritus NRS ≥4 From Baseline to Week 16

Peak pruritus NRS was used by participants to rate the intensity of pruritus during the past 24 hours, with 0 indicating no itch and 10 indicating worst itch possible. Participants were required to have a baseline peak pruritus NRS maximum intensity average of ≥4 during the 7 days prior to randomization for eligibility. Participants were considered non-responders after rescue treatment use. Participants with missing values caused by discontinuation from the study before week 16 due to lack of efficacy, treatment-related AE, or death were considered non-responders. Missing values due to other reasons were imputed using multiple imputation of the continuous data of the weekly average of daily peak pruritus NRS.

Time frame: Baseline, Week 16

Number of Participants With At Least One Treatment-emergent Adverse Event (TEAE) Through Week 52

Time frame: Through Week 52

Number of Participants With At Least One Serious TEAE Through Week 52

Time frame: Through Week 52

Number of Participants With At Least One TE Adverse Event of Special Interest (AESI) Through Week 52

Time frame: Through Week 52

Number of Participants With At Least One TEAE Through Week 64

Time frame: Week 52 through Week 64

Number of Participants With At Least One Serious TEAE Through Week 64

Time frame: Week 52 through Week 64

Number of Participants With At Least One TE AESI Through Week 64

Time frame: Week 52 through Week 64

Concentrations of Functional Dupilumab in Serum

Time frame: Baseline to Week 64

Number of Participants With TE Anti-drug Antibody (ADA) Response Per Maximum Titer Category

Time frame: Baseline to Week 64