The LMK score is used to quantify the degree of opacification of each sinus on CT scan. The CT scan LMK staging system represents the most widely established method of sinus CT scoring. The LMK total score is based on assessment of the CT scan findings for each sinus area (maxillary, anterior ethmoid, posterior ethmoid, sphenoid, and frontal sinus plus the osteomeatal complex on each side). The extent of sinus opacification is rated on a 3-point scale ranging from 0 = normal to 2 = total opacification. In addition, the osteomeatal complex is graded as 0 = not occluded or 2 = occluded. The maximum score is 12 per side; total score ranges from 0 (normal) to 24 (more opacified) corresponding to the sum of all sinuses and the osteomeatal complexes bilaterally. Higher score indicate worse outcome; a negative change from baseline indicate improvement. Baseline was defined as the last available value before the first dose of study drug.

The intent-to-treat (ITT) population included all randomized participants.

The nasal symptom diary is designed to assess the severity of chronic rhinosinusitis (CRS) nasal symptoms on daily basis. Score range: 0 = no symptoms, 1 = mild symptoms (symptoms clearly present, but minimal awareness and easily tolerated), 2= moderate symptoms (definite awareness of symptoms that is bothersome but tolerable) and 3 = severe symptoms (symptoms that are hard to tolerate, cause interference with activities or daily living). Higher scores denote greater symptom severity; a negative change from baseline indicate improvement. Baseline was defined as the average of the scores in the 7 days prior to the first dose of study drug.

The ITT population included all randomized participants.

The bilateral endoscopy NPS is determined by the clinician who assesses nasal polyp formation. Polyps on each side of the nose are graded based on polyp size; scores: 0 = no polyps; 1 = small polyps in the middle meatus not reaching below the inferior border of the middle turbinate; 2 = polyps reaching below the lower border of the middle turbinate; 3 = large polyps reaching the lower border of the inferior turbinate or polyps medial to the middle turbinate and 4 = large polyps causing complete obstruction. The total score is the sum of the right and left nostrils, ranging from 0 (no obstruction) to 8 (complete obstruction); higher score indicating worse outcome; a negative change from baseline indicate improvement. Baseline was defined as the last available value before the first dose of study drug.

The ITT population included all randomized participants.

The LMK score is used to quantify the degree of opacification of each sinus on CT scan. The CT scan LMK staging system represents the most widely established method of sinus CT scoring. The LMK total score is based on assessment of the CT scan findings for each sinus area (maxillary, anterior ethmoid, posterior ethmoid, sphenoid, and frontal sinus plus the osteomeatal complex on each side). The extent of sinus opacification is rated on a 3-point scale ranging from 0 = normal to 2 = total opacification. In addition, the osteomeatal complex is graded as 0 = not occluded or 2 = occluded. The maximum score is 12 per side; total score ranges from 0 (normal) to 24 (more opacified) corresponding to the sum of all sinuses and the osteomeatal complexes bilaterally. Higher score indicate worse outcome; a negative change from baseline indicate improvement. Baseline was defined as the last available value before the first dose of study drug.

The ITT population included all randomized participants.

The nasal symptom diary is designed to assess the severity of CRS nasal symptoms on daily basis. The TSS is a composite score consisting of the sum of the following symptoms assessed daily in the morning: nasal congestion/obstruction, decreased/loss of sense of smell, rhinorrhea (average of anterior/posterior nasal discharge). Each of the individual items were scored from 0 = no symptoms to 3 = severe symptoms. TSS is the sum of individual items and ranges between 0 = no symptoms and 9 = severe symptoms. Higher scores on the TSS indicate greater symptom severity; a negative change from baseline indicate improvement. Baseline was defined as the average of the scores in the 7 days prior to the first dose of study drug.

The ITT population included all randomized participants.

The UPSIT (UPSIT 40 odorant test) is a rapid and easy-to-administer method to quantitatively assess human olfactory function. The test consists of 4 booklets, each containing 10 odorants with 1 odorant per page. Above each odorant strip is a multiple-choice question with 4 alternative words to describe the odor and the participant is asked to indicate which word best describes the odor. Each smell has a possible of 4 answers with one being correct, therefore the potential total scores can range from 0 (worst possible score) to 40 (best possible score), with 1 point being awarded for each correctly identified odor. Scores of <=18 were classified as anosmia, 19 to 25 as severe microsmia, 26 to 30 as moderate microsmia, 31 to 34 as mild microsmia, and 35 to 40 as normal smell appreciation. Higher scores indicated better olfactory function; i.e. better sense of smell. Baseline was defined as the last available value before the first dose of study drug.

The ITT population included all randomized participants.

The nasal symptom diary is designed to assess the severity of CRS nasal symptoms on daily basis. Decreased/loss of smell is scored as: 0 = no symptoms, 1 = mild symptoms (symptoms clearly present, but minimal awareness and easily tolerated), 2= moderate symptoms (definite awareness of symptoms that is bothersome but tolerable) and 3 = severe symptoms (symptoms that are hard to tolerate, cause interference with activities or daily living). Higher scores denote greater symptom severity; a negative change from baseline indicate improvement. Baseline was defined as the average of the scores in the 7 days prior to the first dose of study drug.

The ITT population included all randomized participants.

The bilateral endoscopy NPS is determined by the clinician who assesses nasal polyp formation. Polyps on each side of the nose are graded based on polyp size; scores: 0 = no polyps; 1 = small polyps in the middle meatus not reaching below the inferior border of the middle turbinate; 2 = polyps reaching below the lower border of the middle turbinate; 3 = large polyps reaching the lower border of the inferior turbinate or polyps medial to the middle turbinate and 4 = large polyps causing complete obstruction. The total score is the sum of the right and left nostrils, ranging from 0 (no obstruction) to 8 (complete obstruction); higher score indicating worse outcome; a negative change from baseline indicate improvement. Baseline was defined as the last available value before the first dose of study drug.

The ITT population included all randomized participants.

The nasal symptom diary is designed to assess the severity of CRS nasal symptoms on daily basis. Score range: 0 = no symptoms, 1 = mild symptoms (symptoms clearly present, but minimal awareness and easily tolerated), 2= moderate symptoms (definite awareness of symptoms that is bothersome but tolerable) and 3 = severe symptoms (symptoms that are hard to tolerate, cause interference with activities or daily living). Higher scores denote greater symptom severity; a negative change from baseline indicate improvement. Baseline was defined as the average of the scores in the 7 days prior to the first dose of study drug.

The ITT population included all randomized participants.

The SNOT-22 is a validated questionnaire designed to assess the impact of CRS on participants health-related quality of life (HRQoL) and has 22 items covering symptoms, social/emotional impact, productivity, and sleep consequences of CRS. The recall period is past 2 weeks. Each item is rated on a 6-point Likert scale; response options ranging from 0 = no problem to 5 = problem as bad as it can be. A global score ranging from 0 (no impact) to 110 (severe impact) is calculated by summing the responses to all items; higher score indicates greater rhinosinusitis-related health burden; a negative change from baseline indicate improvement. Baseline was defined as the last available value before the first dose of study drug.

The ITT population included all randomized participants. Only those participants with data collected at baseline and Week 52 are reported.

This method is used to calculate the percent occupied by disease. It is performed at locations including ethmoid sinus, frontal sinus, maxillary sinus, and sphenoid sinus. The total volume occupied by disease in all sinuses is reported here. For the analysis, central reading at baseline was used for comparison with Week 52 reading. It is graded on a scale of 0-100%; a higher score is worse and indicates greater volume occupied by disease. A negative change from baseline indicated improvement. Baseline was defined as the last available value before the first dose of study drug.

The ITT population included all randomized participants.

SCS use was defined as the use of SCS for rescue treatment of AFRS or for another reason and was captured by the Investigator (or designee) in electronic case report form (eCRF). Participants who underwent or planned to undergo surgery for AFRS were also recorded in eCRF.

The ITT population included all randomized participants.

The SNOT-22 is a validated questionnaire designed to assess the impact of CRS on participants HRQoL and has 22 items covering symptoms, social/emotional impact, productivity, and sleep consequences of CRS. The recall period is past 2 weeks. Each item is rated on a 6-point Likert scale; response options ranging from 0 = no problem to 5 = problem as bad as it can be. A global score ranging from 0 (no impact) to 110 (severe impact) is calculated by summing the responses to all items; higher score indicates greater rhinosinusitis-related health burden; a negative change from baseline indicate improvement. Baseline was defined as the last available value before the first dose of study drug.

The ITT population included all randomized participants. Only those participants with data collected at baseline and Week 24 are reported.

Blood samples were collected at specified timepoints for the assessment of IgE. Total IgE was measured with a quantitative method approved for diagnostic testing; a negative change from baseline indicate improvement. Baseline was defined as the last available value before the first dose of study drug.

The safety population included all randomized participants who took at least 1 dose of study drug, regardless of the amount of treatment administered.

The nasal symptom diary is designed to assess the severity of CRS nasal symptoms on daily basis. Score range: 0 = no symptoms, 1 = mild symptoms (symptoms clearly present, but minimal awareness and easily tolerated), 2= moderate symptoms (definite awareness of symptoms that is bothersome but tolerable) and 3 = severe symptoms (symptoms that are hard to tolerate, cause interference with activities or daily living). Higher scores denote greater symptom severity; a negative change from baseline indicate improvement. Severity of rhinorrhea (average of anterior [runny nose]/posterior nasal discharge [post-nasal drip]) is presented here. Baseline was defined as the average of the scores in the 7 days prior to the first dose of study drug.

The ITT population included all randomized participants.

The nasal symptom diary is designed to assess the severity of CRS nasal symptoms on daily basis. The TSS is a composite score consisting of the sum of the following symptoms assessed daily in the morning: nasal congestion/obstruction, decreased/loss of sense of smell, rhinorrhea (average of anterior/posterior nasal discharge). Each of the individual items were scored from 0 = no symptoms to 3 = severe symptoms. TSS is the sum of individual items and ranges between 0 = no symptoms and 9 = severe symptoms. Higher scores on the TSS indicate greater symptom severity; a negative change from baseline indicate improvement. Baseline was defined as the average of the scores in the 7 days prior to the first dose of study drug.

The ITT population included all randomized participants.

The rhinosinusitis VAS is used to evaluate the overall severity of the rhinosinusitis. It is a recommended scale to determine the participant's disease severity and to guide the treatment for CRS. The participant is asked to answer the following question: "How troublesome are your symptoms of your rhinosinusitis" on a 10-centimeter VAS from 0 = not troublesome to 10 = worst thinkable troublesome. Based on their score on the VAS, the severity of rhinosinusitis is divided into 3 categories as follows: mild = VAS 0 to 3, moderate = VAS >3 to 7 and severe = VAS >7 to 10; higher score indicating worse outcome; a negative change from baseline indicate improvement. Baseline was defined as the last available value before the first dose of study drug.

The ITT population included all randomized participants. Only those participants with data collected at specified timepoints are reported.

The UPSIT (UPSIT 40 odorant test) is a rapid and easy-to-administer method to quantitatively assess human olfactory function. The test consists of 4 booklets, each containing 10 odorants with 1 odorant per page. Above each odorant strip is a multiple-choice question with 4 alternative words to describe the odor and the participant is asked to indicate which word best describes the odor. Each smell has a possible of 4 answers with one being correct, therefore the potential total scores can range from 0 (worst possible score) to 40 (best possible score), with 1 point being awarded for each correctly identified odor. Scores of <=18 were classified as anosmia, 19 to 25 as severe microsmia, 26 to 30 as moderate microsmia, 31 to 34 as mild microsmia, and 35 to 40 as normal smell appreciation. Higher scores indicated better olfactory function, i.e. better sense of smell. Baseline was defined as the last available value before the first dose of study drug.

The ITT population included all randomized participants.

The nasal symptom diary is designed to assess the severity of CRS nasal symptoms on daily basis. Decreased/loss of smell is scored as: 0 = no symptoms, 1 = mild symptoms (symptoms clearly present, but minimal awareness and easily tolerated), 2= moderate symptoms (definite awareness of symptoms that is bothersome but tolerable) and 3 = severe symptoms (symptoms that are hard to tolerate, cause interference with activities or daily living). Higher scores denote greater symptom severity; a negative change from baseline indicate improvement. Baseline was defined as the average of the scores in the 7 days prior to the first dose of study drug.

The ITT population included all randomized participants.

An AE was any untoward medical occurrence in a participant or clinical study participant, temporally associated with the use of study drug, whether or not considered related to the study drug. A SAE was defined as any untoward medical occurrence that, at any dose: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent disability/incapacity, was a congenital anomaly/birth defect or was a medically important event. TEAEs were AEs that developed, worsened or became serious during the treatment-emergent period.

The safety population included all randomized participants who took at least 1 dose of study drug, regardless of the amount of treatment administered.

Blood samples were collected at the specified timepoints to obtain serum concentration of dupilumab.

The pharmacokinetic (PK) population included all participants in the safety population with at least 1 post-baseline PK result. Only those participants with data collected at specified timepoints are reported.

Blood samples were collected at specified timepoints for the assessment of fungal-specific IgE which was measured with a quantitative method approved for diagnostic testing; a negative change from baseline indicated improvement. Baseline was defined as the last available value before the first dose of study drug.

The safety population included all randomized participants who took at least 1 dose of study intervention, regardless of the amount of treatment administered. Only those participants with data collected at Baseline and Week 52 are reported.

Plasma samples were collected to evaluate antibodies to dupilumab. Treatment-emergent ADA responses were defined as a positive response in the ADA assay post first dose, when baseline results were negative or missing.

The ADA population included all participants from the safety population with at least 1 post-baseline ADA result (positive, negative or inconclusive).