Trial Outcomes & Findings for Dose Ranging Study of Amlitelimab in Adult Participants With Moderate-to-severe Asthma (NCT NCT05421598)

The study was conducted at 112 centers in 14 countries. A total of 910 participants were screened from 30 June 2022 to 31 October 2023, of which 473 were screen failures. Screen failures were mainly due to not meeting the eligibility criteria.

A total of 437 participants were randomized in a ratio of 2:1:2:2 to one of the following groups: placebo, amlitelimab 62.5 milligrams (mg) with 125 mg loading dose, amlitelimab 125 mg with 250 mg loading dose, or amlitelimab 250 mg with 500 mg loading dose. Randomization was stratified by region, screening blood eosinophil count (\<300 cells per \[/\] microliter \[mcL\] and \>=300 cells/mcL), and number of severe asthma exacerbations in the previous 12 months (=1 or \>1 exacerbations).

Dose Ranging Study of Amlitelimab in Adult Participants With Moderate-to-severe Asthma

Severe asthma exacerbation event was defined as worsening of asthma requiring the use of systemic corticosteroids for \>=3 days or, in the case of a stable maintenance regimen of oral corticosteroids (OCS) for the treatment of asthma, a doubling of the dose for 3 or more days, or hospitalization or emergency room visit because of asthma requiring systemic corticosteroids. Annualized rate was the total number of severe asthma exacerbation events divided by the total observation duration and was estimated based on negative binomial regression.

The FEV1 was the volume of air exhaled from the lungs in the first second of a forced expiration as measured by spirometer. The pre-BD spirometry was performed after a wash out period of BDs according to their action duration. Baseline was defined as the last available value before the first dose of double-blind study treatment.

The ACQ was a questionnaire that measured the adequacy of asthma control and any changes in asthma control that occurred spontaneously or as a result of treatment. The ACQ-5 had five questions on the asthma symptoms and participants were asked to recall how their asthma had been during the previous week. Each item of the ACQ was measured on a 7-point response scale (0=no impairment, 6=maximum impairment). The ACQ score was the mean of the item responses and ranged from 0 (totally controlled) and 6 (severely uncontrolled). A high score indicated low asthma control. Baseline was defined as the last available value before the first dose of double-blind study treatment.

The AQLQ(S) was a self-administered participant reported outcome (PRO) to measure the functional impairments that were most troublesome to adolescents and adults \>=12 years of age as a result of their asthma over the past two weeks. The instrument comprised of 32 items, each rated on a 7-point Likert scales from 1 (severely impaired) to 7 (not impaired). The AQLQ(S) had 4 domains: symptoms (12 items), activity limitation (11 items, 5 of which were individualized), emotional function (5 items), and environmental exposure (4 items). The global score was the mean of response to each of the 32 questions and ranged from 1 (severe impairment) to 7 (no impairment). Higher scores indicated better quality of life. Baseline was defined as the last available value before the first dose of double-blind study treatment.

The FEV1 was the volume of air exhaled from the lungs in the first second of a forced expiration as measured by spirometer. The post-BD spirometry was performed within 30 minutes after administration of BD. Baseline was defined as the last available value before the first dose of double-blind study treatment.

The FEV1 was the volume of air exhaled from the lungs in the first second of a forced expiration as measured by spirometer. The pre-BD spirometry was performed after a wash out period of BDs according to their action duration. The post-BD spirometry was performed within 30 minutes after administration of BD. Baseline was defined as the last available value before the first dose of double-blind study treatment.

The ACQ was a questionnaire that measured the adequacy of asthma control and any changes in asthma control that occurred spontaneously or as a result of treatment. The ACQ-5 had five questions on the asthma symptoms and participants were asked to recall how their asthma had been during the previous week. Each item of the ACQ was measured on a 7-point response scale (0=no impairment, 6=maximum impairment). The ACQ score was the mean of the item responses and ranged from 0 (totally controlled) and 6 (severely uncontrolled). A high score indicated low asthma control. Baseline was defined as the last available value before the first dose of double-blind study treatment.

Time to first severe asthma exacerbation event was defined as the onset date of the first severe asthma exacerbation minus randomization date + 1. Severe asthma exacerbation event was defined as worsening of asthma requiring the use of systemic corticosteroids for \>=3 days or, in the case of a stable maintenance regimen of OCS for the treatment of asthma, a doubling of the dose for 3 or more days, or hospitalization or emergency room visit because of asthma requiring systemic corticosteroids.

The FEV1 was the volume of air exhaled from the lungs in the first second of a forced expiration as measured by spirometer. The pre-BD spirometry was performed after a wash out period of BDs according to their action duration. The post-BD spirometry was performed within 30 minutes after administration of BD. Baseline was defined as the last available value before the first dose of double-blind study treatment.

The PEF was a participant's maximum speed of expiration as measured with a peak flow meter. The pre-BD spirometry was performed after a wash out period of BDs according to their action duration. The post-BD spirometry was performed within 30 minutes after administration of BD. Baseline was defined as the last available value before the first dose of double-blind study treatment.

The FVC was defined as the volume of air that can be forcibly blown out after full inspiration in the upright position as measured by spirometer. The pre-BD spirometry was performed after a wash out period of BDs according to their action duration. The post-BD spirometry was performed within 30 minutes after administration of BD. Baseline was defined as the last available value before the first dose of double-blind study treatment.

The FEF was the amount of air which can be forcibly exhaled from the lungs in the first second of a forced exhalation. The FEF 25-75% was defined as the FEF at 25% to 75% of FVC, where FVC was defined as the volume of air that can be forcibly blown out after full inspiration in the upright position. The pre-BD spirometry was performed after a wash out period of BDs according to their action duration. The post-BD spirometry was performed within 30 minutes after administration of BD. Baseline was defined as the last available value before the first dose of double-blind study treatment.

FeNO was a measure of nitric oxide in exhaled breath produced by epithelial cells in the lung and considered as a biomarker of Type-2 inflammation in asthma. FeNO levels were collected on site with a dedicated medical device. The FeNO test was completed prior to impulse oscillometry and spirometry. Baseline was defined as the last available value before the first dose of double-blind study treatment.

LOAC events were defined by one or several of the following criteria: a 30% or greater reduction from baseline in morning PEF on 2 consecutive days; \>=6 additional reliever puffs of short-acting beta 2-agonists (SABA) or \>=4 additional puffs of low-dose ICS/formoterol in a 24-hour period (compared to baseline) on 2 consecutive days; increase in ICS \>=4 times than the Visit 2 dose; worsening of asthma requiring the use of systemic corticosteroids for \>=3 days or, in the case of a stable maintenance regimen of OCS for the treatment of asthma, a doubling of the dose for 3 or more days; or hospitalization or emergency room visit because of asthma requiring systemic corticosteroids severe exacerbation event. Annualized rate was the total number of severe asthma exacerbation events divided by the total observation duration and was estimated based on negative binomial regression.

Time to first LOAC event was defined as the onset date of the first LOAC minus randomization date + 1. LOAC events were defined by one or several of the following criteria: a 30% or greater reduction from baseline in morning PEF on 2 consecutive days; \>=6 additional reliever puffs of SABA or \>=4 additional puffs of low-dose ICS/formoterol in a 24-hour period (compared to baseline) on 2 consecutive days; increase in ICS \>=4 times than the Visit 2 dose; worsening of asthma requiring the use of systemic corticosteroids for \>=3 days or, in the case of a stable maintenance regimen of OCS for the treatment of asthma, a doubling of the dose for 3 or more days; or hospitalization or emergency room visit because of asthma requiring systemic corticosteroids severe exacerbation event.

ADSD and ANSD were PRO measures designed to measure asthma symptoms in adult and adolescent (\>=12 years of age) participants diagnosed with mild-to-severe asthma. Both scales assessed asthma severity based on participant self-report of asthma core symptoms, i.e., difficulty of breathing; wheezing; shortness of breath; chest tightness; chest pain; and cough. Participants were asked to complete ADSD every night before they go to bed, thinking about their asthma symptoms today, from when they got up this morning until now; ANSD when getting up, thinking about their asthma symptoms last night from when they went to bed until now. Both scales consisted 6 items rated using an 11-point numerical rating scale that ranged from 0 (none) to 10 (as bad as you can imagine). Total score was an average of all 6 items for ADSD and ANSD each and therefore ranged from 0 to 10. Higher scores indicated worse outcomes. Baseline: last available value before first dose of double-blind study treatment.

Severe asthma exacerbation event was defined as worsening of asthma requiring the use of systemic corticosteroids for \>=3 days or, in the case of a stable maintenance regimen of OCS for the treatment of asthma, a doubling of the dose for 3 or more days, or hospitalization or emergency room visit because of asthma requiring systemic corticosteroids. Severe asthma exacerbation events requiring hospitalization or emergency room or urgent care visit during the 48-week treatment period were recorded. Annualized rate was the total number of severe asthma exacerbation events divided by the total observation duration and was estimated based on negative binomial regression.

Participants were administered SABA or low-dose ICS/formoterol via oral inhalation as reliever medication as needed during the study and the number of inhalations/day were recorded. Baseline was defined as last available value before first dose of double-blind study treatment.

Blood samples were collected at the specified timepoints for measurement of serum concentrations of amlitelimab.

Serum samples were collected to evaluate antibodies to amlitelimab. Participants with treatment-emergent ADAs were participants with at least one treatment-induced/boosted ADA. Participants with treatment-induced ADAs were participants with ADAs that developed during the treatment-emergent (TE) period and without pre-existing ADA (including participants without pre-treatment samples). Participants with treatment-boosted ADAs were participants with pre-existing ADAs that were boosted during the TE period to a significant higher titer than the baseline. Number of participants with treatment-emergent ADAs are reported.

Adverse event (AE): any untoward medical occurrence in participant or clinical study participant, temporally associated with use of study treatment, whether or not considered related to study treatment. TEAEs: AEs that developed, worsened or became serious during TE period. Serious AE: any untoward medical occurrence that at any dose, met one or more of criteria: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was congenital anomaly/birth defect or was significant medical event that jeopardized the participant or required medical or surgical intervention to prevent one of above outcomes. AESI: AE (serious or non-serious) of scientific and medical concern specific to Sponsor's product or program, for which ongoing monitoring and immediate notification by Investigator to Sponsor was required. Percentages are rounded off to tenth decimal place.

The AQLQ(S) was a self-administered PRO to measure the functional impairments that were most troublesome to adolescents and adults \>=12 years of age as a result of their asthma over the past two weeks. The instrument comprised of 32 items, each rated on a 7-point Likert scales from 1 to (severely impaired) to 7 (not impaired). The AQLQ(S) had 4 domains: symptoms (12 items), activity limitation (11 items, 5 of which were individualized), emotional function (5 items), and environmental exposure (4 items). The global score was the mean of response to each of the 32 questions and ranged from 1 (severe impairment) to 7 (no impairment). Higher scores indicated better quality of life. Baseline was defined as the last available value before the first dose of double-blind study treatment.

SGRQ was 50-item questionnaire to measure and quantify health status in adult participants with chronic airflow limitation and consisted of three domains: symptoms (8 items \[covered symptomatology, frequency and severity of cough, sputum production, wheeze, breathlessness, duration and frequency of attacks of breathlessness/wheeze\]), activity (16 items \[covered disturbances to participants' daily physical activities\]), impacts (26 items \[covered effects that chest troubles had on participants' daily life and psycho-social functions\]). Global score was calculated by summing all positive responses in questionnaire and expressing result as percentage of total weight for questionnaire. Global and domain scores ranged from 0 to 100 with 100=worst possible health status and 0=best possible health status. Higher score=worse health status/heath related quality of life. Baseline: last available value before first dose of double-blind study treatment.

SGRQ was 50-item questionnaire to measure and quantify health status in adult participants with chronic airflow limitation and consisted of three domains: symptoms (8 items\[covered symptomatology, frequency and severity of cough, sputum production, wheeze, breathlessness, duration and frequency of attacks of breathlessness/wheeze\]), activity (16 items\[covered disturbances to participants' daily physical activities\]), impacts (26 items\[covered effects that chest troubles had on participants' daily life and psycho-social functions\]). Global score was calculated by summing all positive responses in questionnaire and expressing result as percentage of total weight for questionnaire. Global and domain scores ranged from 0 to 100; 100=worst possible health status and 0=best possible health status. Higher score=worse health status/heath related quality of life. Baseline:last available value before first dose of double-blind study treatment. Percentages are rounded off to tenth decimal place.

The ACQ was a questionnaire that measured the adequacy of asthma control and any changes in asthma control that occurred spontaneously or as a result of treatment. The ACQ-5 had five questions on the asthma symptoms and participants were asked to recall how their asthma had been during the previous week. The ACQ-6 included an additional item that scored the average number of daily puffs needed from a SABA BD during the past week and the ACQ-7 included this SABA item, plus a final clinic-assessed item scoring FEV1% predicted. Each item of the ACQ was measured on a 7-point response scale (0=no impairment, 6=maximum impairment). The ACQ-6 and ACQ-7 scores were the mean of the item responses in the respective scales and ranged from 0 (totally controlled) and 6 (severely uncontrolled). A high score indicated low asthma control. Baseline was defined as the last available value before the first dose of double-blind study treatment.