Clinical Pharmacology for Fasenra
Mechanism Of Action
Benralizumab is a humanized afucosylated, monoclonal antibody (IgG1, kappa) that directly binds to the alpha subunit of the human interleukin-5 receptor (IL-5Rα) with a dissociation constant of 11 pM. The IL-5 receptor is expressed on the surface of eosinophils and basophils. In an in vitro setting, the absence of fucose in the Fc domain of benralizumab facilitates binding (45.5 nM) to FcγRIII receptors on immune effector cells, such as natural killer (NK) cells, leading to apoptosis of eosinophils and basophils through antibody-dependent cell-mediated cytotoxicity (ADCC).
Inflammation is an important component in the pathogenesis of asthma and EGPA. Multiple cell types (e.g., mast cells, eosinophils, neutrophils, macrophages, lymphocytes) and mediators (e.g., histamine, eicosanoids, leukotrienes, cytokines) are involved in inflammation. Benralizumab, by binding to the IL-5Rα chain, reduces eosinophils through ADCC; however, the mechanism of benralizumab action in asthma and EGPA has not been definitively established.
Pharmacodynamics
In the 52-week Phase 2 dose-ranging trial, asthma patients received 1 of 3 doses of benralizumab [2 mg (n=81), 20 mg (n=81), or 100 mg (n=222)] or placebo (n=222). All doses were administered every 4 weeks for the first 3 doses, followed by every 8 weeks thereafter. Median blood eosinophil levels at baseline were 310, 280, 190 and 190 cells/μL in the 2, 20, and 100 mg benralizumab and placebo groups, respectively. Dose-dependent reductions in blood eosinophils were observed. At the time of the last dose (Week 40), median blood eosinophil counts were 100, 50, 40, 170 cells/μL in the 2, 20, and 100 mg benralizumab and placebo groups, respectively.
A reduction in blood eosinophil counts was observed 24 hours post dosing in an asthma Phase 2 trial.
In SIROCCO and CALIMA, following SC administration of benralizumab at the recommended dose blood eosinophils were reduced to a median absolute blood eosinophil count of 0 cells/μL [see Clinical Studies]. This magnitude of reduction was observed at the first time point, 4 weeks of treatment, and was maintained throughout the treatment period.
Treatment with benralizumab was also associated with reductions in blood basophils, which was consistently observed across all asthma clinical studies. In the Phase 2 dose-ranging asthma trial, blood basophil counts were measured by flow cytometry. Median blood basophil counts were 45, 52, 46, and 40 cells/μL in the 2 mg, 20 mg and 100 mg benralizumab and placebo groups, respectively. At 52 weeks (12 weeks after the last dose), median blood basophil counts were 42, 18, 17, and 46 cells/μL in the 2 mg, 20 mg and 100 mg benralizumab and placebo groups, respectively.
In TATE, a 48-week trial with patients aged 6 to 11 years who had severe asthma, and with an eosinophilic phenotype [see Use In Specific Populations], the magnitude of blood eosinophil reduction was similar to that observed in adults and adolescents. Median blood eosinophil levels at baseline were 400 and 340 cells/μL in patients weighing <35 kg and ≥35 kg, respectively. Across all post-dose time points, median eosinophil counts reduced to 10 to 20 cells/μL in patients weighing <35 kg, and to 20 to 30 cells/μL in patients weighing ≥35 kg. Blood eosinophil reduction was observed at the first time point, 4 weeks of treatment, and was maintained throughout the treatment period.
In patients with EGPA, reduction of blood eosinophils was consistent with the effect observed in asthma trials. Median absolute blood eosinophil levels in the benralizumab group at baseline were 240 cells/μL. Following SC administration of benralizumab at the recommended dosage in patients with EGPA, blood eosinophils were reduced to a median absolute blood eosinophil count of 20 to 30 cells/μL. Blood eosinophil reduction was seen at the first observed time point, 1 week of treatment, and was maintained throughout the 52-week treatment period.
Pharmacokinetics
The pharmacokinetic properties of benralizumab below are based on the population pharmacokinetic analyses from the asthma trials. Findings in EGPA were generally consistent with those in asthma although a lower clearance is predicted for patients with EGPA relative to patients with asthma [see Elimination].
The pharmacokinetics of benralizumab was approximately dose-proportional in adult and adolescent patients with asthma following subcutaneous administration over a dose range of 20 to 200 mg.
Absorption
Following subcutaneous administration to patients with asthma, the absorption half-life was approximately 3.5 days. Based on population pharmacokinetic analysis, the estimated absolute bioavailability was approximately 59% and there was no clinically relevant difference in relative bioavailability in the administration to the abdomen, thigh, or arm.
Distribution
Based on population pharmacokinetic analysis, central and peripheral volume of distribution of benralizumab was 3.1 L and 2.5 L, respectively, for a 70 kg individual.
Elimination
From population pharmacokinetic analysis, benralizumab exhibited linear pharmacokinetics and no evidence of target receptor-mediated clearance pathway. The estimated typical systemic clearance (CL) for benralizumab was 0.29 L/d for an asthma patient weighing 70 kg. The estimated typical CL was 0.22 L/d for patients with EGPA. Following subcutaneous administration in patients with asthma, the elimination half-life was approximately 15.5 days.
Metabolism
Benralizumab is a humanized IgG1 monoclonal antibody that is degraded by proteolytic enzymes widely distributed in the body and not restricted to hepatic tissue.
Specific populations
Age
Based on population pharmacokinetic analysis, age did not affect benralizumab clearance.
Gender, Race
A population pharmacokinetics analysis indicated that there was no significant effect of gender and race on benralizumab clearance.
Patients With Renal impairment
No formal clinical studies have been conducted to investigate the effect of renal impairment on benralizumab. Based on population pharmacokinetic analysis, benralizumab clearance was comparable in subjects with creatinine clearance values between 30 and 80 mL/min and patients with normal renal function. There are limited data available in subjects with creatinine clearance values less than 30 mL/min; however, benralizumab is not cleared renally.
Patients With Hepatic impairment
No formal clinical studies have been conducted to investigate the effect of hepatic impairment on benralizumab. IgG monoclonal antibodies are not primarily cleared via hepatic pathway; change in hepatic function is not expected to influence benralizumab clearance. Based on population pharmacokinetic analysis, baseline hepatic function biomarkers (ALT, AST, and bilirubin) had no clinically relevant effect on benralizumab clearance.
Pediatric Patients
Benralizumab pharmacokinetics following subcutaneous administration of 10 mg or 30 mg in patients aged 6 to 11 years with severe asthma and with an eosinophilic phenotype asthma was investigated in the initial 16-week treatment phase of TATE, a 48-week open-label trial. Among patients aged 6 to 11 years weighing <35 kg who received 10 mg, the median trough concentration at Week 16 was similar to that of adults and adolescents who received 30 mg. Among patients aged 6 to 11 years weighing ≥35 kg who received 30 mg, the median trough concentration at Week 16 was 62% higher relative to adults and adolescents receiving the same dose, due to lower body weight in pediatric patients.
Drug Interaction Studies
No formal drug-drug interaction studies have been conducted.
Cytochrome P450 enzymes, efflux pumps and protein-binding mechanisms are not involved in the clearance of benralizumab. There is no evidence of IL-5Rα expression on hepatocytes and eosinophil depletion does not produce chronic systemic alterations of proinflammatory cytokines.
An effect of benralizumab on the pharmacokinetics of co-administered medications is not expected. Based on the population analysis, commonly co-administered medications had no effect on benralizumab clearance in patients with asthma.
Immunogenicity
The observed incidence of anti-drug antibodies (ADA) is highly dependent on the sensitivity and specificity of the assay. Differences in assay methods preclude meaningful comparisons of the incidence of ADA in the studies described below with the incidence of ADA in other studies, including those of benralizumab or of other benralizumab products.
In adult and adolescent patients with asthma, the incidence of ADA to benralizumab in patients treated with FASENRA at the recommended dosing regimen during the 48 to 56-week treatment period was 13%. A total of 12% of patients treated with FASENRA developed neutralizing antibodies.
In pediatric patients 6 to 11 years with severe asthma and with an eosinophilic phenotype, the incidence of ADA to benralizumab during an open-label 48-week treatment period was comparable to adult and adolescent patients.
In patients with EGPA, the incidence of ADA to benralizumab during the active-controlled 52-week treatment period was 9% (6 out of 67 patients). Neutralizing antibody activity was detected in one of the ADA positive patients.
Anti-Drug Antibody Effects On Pharmacokinetics And Pharmacodynamics
Anti-benralizumab antibodies were associated with increased clearance of benralizumab and increased blood eosinophil levels in asthma patients with high ADA titers compared to antibody negative patients. Reduced benralizumab trough concentrations were observed in one EGPA patient with high ADA titers.
In the asthma trials with adult and adolescent patients and in the EGPA trial, no evidence of an association of ADA with efficacy or safety was observed.
Clinical Studies
Clinical Studies In Patients With Asthma
The efficacy of FASENRA for the add-on maintenance treatment of severe asthma, and with an eosinophilic phenotype was evaluated in two randomized, double-blind, parallel-group, placebo-controlled, exacerbation trials, SIROCCO (NCT01928771) and CALIMA (NCT01914757), for 48 and 56 weeks in duration, respectively. Furthermore, the effects of FASENRA in the reduction of oral corticosteroid use and effect on lung function were evaluated in clinical trials, ZONDA (NCT02075255) and a 12-week lung function trial (NCT02322775), respectively.
SIROCCO and CALIMA were randomized, double-blind, parallel-group, placebo-controlled, exacerbation trials in patients 12 years of age and older and 48 and 56 weeks in duration, respectively. The trials randomized a total of 2,510 patients. Patients were required to have a history of 2 or more asthma exacerbations requiring oral or systemic corticosteroid treatment in the past 12 months, ACQ-6 score of 1.5 or more at screening, and reduced lung function at baseline [pre-bronchodilator FEV1 below 80% in adults, and below 90% in adolescents] despite regular treatment with high dose ICS (SIROCCO) or with medium or high dose ICS (CALIMA) plus a long-acting beta agonist (LABA) with or without oral corticosteroids (OCS) and additional asthma controller medications. Patients were stratified by geography, age, and blood eosinophils count (≥300 cells/μL or <300 cells/μL). FASENRA administered once every 4 weeks for the first 3 doses, and then every 4 or 8 weeks thereafter as add-on to background treatment was evaluated compared to placebo.
All subjects continued their background asthma therapy throughout the duration of the trials.
ZONDA was a randomized, double-blind, parallel-group, OCS reduction trial in 220 adult patients with asthma. Patients were required treatment with daily OCS (7.5 to 40 mg per day) in addition to regular use of high-dose ICS and LABA with or without additional controller(s). The trial included an 8-week run-in period during which the OCS was titrated to the minimum effective dose without losing asthma control. For the purposes of the OCS dose titration, asthma control was assessed by the investigator based on a patient’s FEV1, peak expiratory flow, nighttime awakenings, short-acting bronchodilator rescue medication use or any other symptoms that would require an increase in OCS dose. Baseline median OCS dose was similar across all treatment groups. Patients were required to have blood eosinophil counts greater than or equal to 150 cells/μL and a history of at least one exacerbation in the past 12 months. The baseline median OCS dose was 10 mg (range: 8 to 40 mg) for all 3 treatment groups (placebo, FASENRA every 4 weeks, and FASENRA every 4 weeks for the first 3 doses, and then once every 8 weeks).
While 2 dosing regimens were studied in SIROCCO, CALIMA, and ZONDA, the recommended dosing regimen is 30 mg FASENRA administered every 4 weeks for the first 3 doses, then every 8 weeks thereafter [see DOSAGE AND ADMINISTRATION].
Table 3: Demographics and Baseline Characteristics of Asthma Trials
|
Total Population |
SIROCCO
(N=1204) |
CALIMA
(N=1306) |
ZONDA
(N=220) |
| Mean age (yr) |
49 |
49 |
51 |
| Female (%) |
66 |
62 |
61 |
| White (%) |
73 |
84 |
93 |
| Duration of asthma, median (yr) |
15 |
16 |
12 |
| Never smoked (%) |
80 |
78 |
79 |
| Mean baseline FEV1 pre-bronchodilator (L) |
1.67 |
1.76 |
1.85 |
| Mean baseline % predicted FEVi |
57 |
58 |
60 |
| Mean post-SABA FEVi/FVC (%) |
66 |
65 |
62 |
| Mean baseline eosinophil count (cells/μL) |
472 |
472 |
575 |
| Mean number of exacerbations in previous year |
3 |
3 |
3 |
Exacerbations
The primary endpoint for SIROCCO and CALIMA was the rate of asthma exacerbations in patients with baseline blood eosinophil counts of greater than or equal to 300 cells/μL who were taking high-dose ICS and LABA. Asthma exacerbation was defined as a worsening of asthma requiring use of oral/systemic corticosteroids for at least 3 days, and/or emergency department visits requiring use of oral/systemic corticosteroids and/or hospitalization. For patients on maintenance oral corticosteroids, an asthma exacerbation requiring oral corticosteroids was defined as a temporary increase in stable oral/systemic corticosteroids for at least 3 days or a single depo-injectable dose of corticosteroids. In SIROCCO, 35% of patients receiving FASENRA experienced an asthma exacerbation compared to 51% on placebo. In CALIMA, 40% of patients receiving FASENRA experienced an asthma exacerbation compared to 51% on placebo (Table 4).
Table 4: Rate of Exacerbations, SIROCCO and CALIMA (ITT Population)*
| Trial |
Treatment |
Exacerbations per year |
| Rate |
Difference |
Rate Ratio (95% CI) |
| All exacerbations |
| SIROCCO |
FASENRA†
(n=267) |
0.74 |
-0.78 |
0.49
(0.37, 0.64) |
|
Placebo (n=267) |
1.52 |
-- |
-- |
| CALIMA |
FASENRA† (n=239) |
0.73 |
-0.29 |
0.72
(0.54, 0.95) |
|
Placebo (n=248) |
1.01 |
-- |
-- |
| Exacerbations requiring hospitalization/emergency room visit |
| SIROCCO |
FASENRA† (n=267) |
0.09 |
-0.16 |
0.37
(0.20, 0.67) |
|
Placebo (n=267) |
0.25 |
-- |
-- |
| CALIMA |
FASENRA† (n=239) |
0.12 |
0.02 |
1.23
(0.64, 2.35) |
|
Placebo (n=248) |
0.10 |
-- |
-- |
| Exacerbations requiring hospitalization |
| SIROCCO |
FASENRA† (n=267) |
0.07 |
-0.07 |
0.48
(0.22, 1.03) |
|
Placebo (n=267) |
0.14 |
-- |
-- |
| CALIMA |
FASENRA†
(n=239) |
0.07 |
0.02 |
1.48
(0.65, 3.37) |
|
Placebo (n=248) |
0.05 |
-- |
-- |
* Baseline blood eosinophil counts of greater than or equal to 300 cells/μL and taking high-dose ICS
† FASENRA 30 mg administered every 4 weeks for the first 3 doses, and every 8 weeks thereafter |
The time to first exacerbation was longer for the patients receiving FASENRA compared with placebo in SIROCCO (Figure 2). Similar findings were seen in CALIMA.
Figure 2: Kaplan-Meier Cumulative Incidence Curves for Time to First Exacerbation, SIROCCO
Subgroup analyses from SIROCCO and CALIMA identified patients with a higher prior exacerbation history and baseline blood eosinophil count as potential predictors of improved treatment response. Reductions in exacerbation rates were observed irrespective of baseline peripheral eosinophil counts; however, patients with a baseline blood eosinophil count ≥300 cells/μL showed a numerically greater response than those with counts <300 cells/μL. In both trials patients with a history of 3 or more exacerbations within the 12 months prior to FASENRA randomization showed a numerically greater exacerbation response than those with fewer prior exacerbations.
Oral Corticosteroid Reduction
ZONDA evaluated the effect of FASENRA on reducing the use of maintenance oral corticosteroids in adult patients with asthma. The primary endpoint was percent reduction from baseline of the final OCS dose during Weeks 24 to 28, while maintaining asthma control (see definition of asthma control in trial description). Compared to placebo, patients receiving FASENRA achieved greater reductions in daily maintenance oral corticosteroid dose, while maintaining asthma control. The median percent reduction in daily OCS dose from baseline was 75% in patients receiving FASENRA (95% CI: 60, 88) compared to 25% in patients receiving placebo (95% CI: 0, 33). Reductions of 50% or higher in the OCS dose were observed in 48 (66%) patients receiving FASENRA compared to those receiving placebo 28 (37%). The proportion of patients with a mean final dose less than or equal to 5 mg at Weeks 24 to 28 was 59% for FASENRA and 33% for placebo (odds ratio 2.74, 95% CI: 1.41, 5.31). Only patients with an optimized baseline OCS dose of 12.5 mg or less were eligible to achieve a 100% reduction in OCS dose during the study. Of those patients, 52% (22 of 42) receiving FASENRA and 19% (8 of 42) on placebo achieved a 100% reduction in OCS dose. Exacerbations resulting in hospitalization and/or ER visit were also assessed as a secondary endpoint. In this 28-week trial, patients receiving FASENRA had 1 event while those on placebo had 14 events (annualized rate 0.02 and 0.32, respectively; rate ratio of 0.07, 95% CI: 0.01, 0.63).
Lung Function
Change from baseline in mean FEV1 was assessed in SIROCCO, CALIMA, and ZONDA as a secondary endpoint. Compared with placebo, FASENRA provided consistent improvements over time in the mean change from baseline in FEV1 (Figure 3 and Table 5).
Figure 3: Mean Change from Baseline in Pre-Bronchodilator FEV1 (L), CALIMA
Table 5: Change from Baseline in Mean Pre-Bronchodilator FEV1 (L) at End of Trial*
| Trial |
Difference from Placebo in Mean Change from Pre-Bronchodilator Baseline FEV1 (L) (95% CI) |
| SIROCCO |
0.159 (0.068, 0.249) |
| CALIMA |
0.116 (0.028, 0.204) |
| ZONDA |
0.112 (-0.033, 0.258) |
| *Week 48 in SIROCCO, Week 56 in CALIMA, Week 28 in ZONDA. |
Subgroup analyses also showed greater improvements in FEV1 in patients with higher baseline blood eosinophil counts and more frequent prior exacerbation history.
The clinical program for FASENRA also included a 12-week, randomized, double-blind, placebo-controlled lung function trial conducted in 211 adult patients with mild to moderate asthma. Patients were treated with placebo or benralizumab 30 mg SC every 4 weeks for 3 doses. Lung function, as measured by the change from baseline in FEV1 at Week 12 was improved in the benralizumab treatment group compared to placebo.
Patient Reported Outcomes
The Asthma Control Questionnaire-6 (ACQ-6) and Standardized Asthma Quality of Life Questionnaire for 12 Years and Older (AQLQ(S)+12) were assessed in SIROCCO, CALIMA, and ZONDA. The responder rate for both measures was defined as improvement in score of 0.5 or more as threshold at the end of SIROCCO, CALIMA, and ZONDA (48, 56, and 28 weeks, respectively). In SIROCCO, the ACQ-6 responder rate for FASENRA was 60% vs 50% placebo (odds ratio 1.55; 95% CI: 1.09, 2.19). In CALIMA, the ACQ-6 responder rate for FASENRA was 63% vs 59% placebo (odds ratio 1.16; 95% CI: 0.80, 1.68). In SIROCCO, the responder rate for AQLQ(S)+12 for FASENRA was 57% vs 49% placebo (odds ratio 1.42; 95% CI: 0.99, 2.02), and in CALIMA, 60% FASENRA vs 59% placebo (odds ratio of 1.03; 95% CI: 0.70,1.51). Similar results were seen in ZONDA.
Clinical Studies In Patients With Eosinophilic Granulomatosis With Polyangiitis
The efficacy of FASENRA for eosinophilic granulomatosis with polyangiitis (EGPA) was evaluated in a randomized, double-blind, active-controlled, noninferiority clinical trial (MANDARA [NCT04157348]) of 52-weeks duration. The trial enrolled a total of 140 adults aged 18 years and older with EGPA. Patients were required to have asthma, eosinophilia (1,000 cells/uL or >10% of leukocytes) and a history of relapsing or refractory disease treated with background prednisolone/prednisone with or without immunosuppressive therapy. Patients were randomized to receive FASENRA 30 mg administered subcutaneously every 4 weeks or mepolizumab 300 mg administered subcutaneously every 4 weeks in addition to continued background therapy. Starting at Week 4, the oral corticosteroid (OCS) dose was tapered at the discretion of the investigator. The MANDARA trial was a non-inferiority trial and was not designed to assess whether FASENRA was superior to mepolizumab. The pre-specified noninferiority (NI) margin was a treatment difference of -25%. The secondary endpoints (accrued duration of remission, relapse, OCS reduction and the asthma control questionnaire-6) were not included in the pre-specified multiple testing procedure for statistical significance.
The demographics and baseline characteristics of patients in MANDARA are provided in Table 6.
Table 6: Demographics and Baseline Characteristics of Patients with EGPA in the MANDARA Trial
|
MANDARA
(N=140) |
| Mean age (years) |
52 |
| Female (%) |
60 |
| White (%) |
79 |
| Asian (%) |
12 |
| Other (%) |
4 |
| Hispanic or Latino (%) |
3 |
| Time since diagnosis of EGPA, years, mean (SD) |
5.2 (5.6) |
| History of ≥1 confirmed relapse in past 2 years (%) |
79 |
| Refractory disease (%) |
60 |
| Baseline oral corticosteroid* daily dose, mg, median (range) |
10 (5 - 40) |
| Baseline BVAS, median (range) |
0 (0 - 18) |
| BVAS=0 (%) |
52 |
| Receiving immunosuppressive therapy† (%) |
36 |
| ANCA positive‡ (%) |
29 |
| Biopsy Evidence of Eosinophilic Vasculitis/Inflammation (%) |
38 |
SD=standard deviation; BVAS=Birmingham vasculitis activity score.
* Prednisone or prednisolone equivalent.
† Azathioprine, methotrexate, mycophenolic acid.
‡ Anti-neutrophil cytoplasmic antibody (ANCA) positive historically or at screening. |
Remission
The primary endpoint in MANDARA was the proportion of patients in remission, defined as Birmingham Vasculitis Activity Score (BVAS)=0 (no active vasculitis) plus prednisolone/prednisone dose ≤4 mg/day, at both Week 36 and Week 48. The BVAS is a clinician-completed tool, that is divided into 9 organ-based systems, to assess clinically active vasculitis that would likely require treatment, after exclusion of other causes. As shown in Table 7, FASENRA demonstrated noninferiority to mepolizumab for the primary endpoint of remission and the components of remission.
Table 7: Remission and Components of Remission in Patients with EGPA in MANDARA Trial
|
Remission (OCS≤4 mg/day + BVAS=0) |
OCS≤4 mg/day |
BVAS=0 |
FASENRA*
N=70 |
Mepo†
N=70 |
FASENRA*
N=70 |
Mepo†
N=70 |
FASENRA*
N=70 |
Mepo†
N=70 |
| Patients in remission at both Weeks 36 and 48 |
| Patients, n (%)‡ |
41 (59) |
40 (57) |
43 (62) |
41 (58) |
58 (83) |
59 (84) |
| Differences in remission rate (%)‡(95% CI) |
2.7
(-13, 18)§ |
---- |
4.1
(-11, 19) |
---- |
-1.2
(-13, 11) |
---- |
N=number of patients in analysis.
* FASENRA 30 mg administered subcutaneously every 4 weeks.
† Mepolizumab (Mepo) 300 mg administered subcutaneously every 4 weeks.
‡ Model adjusted percentages.
§ NI margin -25% with 2.5% 1 sided significance level. Since the lower bound of the 95% CI for the treatment difference was >-25%, effectiveness of FASENRA was demonstrated to be noninferior to the effectiveness of mepolizumab. |
Using an alternative remission definition of BVAS=0 plus prednisolone/ prednisone ≤7.5 mg/day, consistent efficacy between groups for these endpoints was observed.
Accrued Duration of Remission
Total accrued duration of remission was similar in FASENRA compared to mepolizumab (odds ratio 1.4, 95% CI: 0.75, 2.5). Results for accrued duration of remission are shown in Table 8. The proportion of patients achieving remission within the first 24 weeks of treatment and remaining in remission through Week 52 was 42% for FASENRA and 37% for mepolizumab (difference in responder rate 5.5%, 95% CI: -9.3, 20). This result was not statistically significant as there was no pre-specified multiple testing procedure.
Table 8: Accrued Duration of Remission in Patients with EGPA in the MANDARA Trial
|
Remission (OCS≤4 mg/day + BVAS=0) |
OCS≤4 mg/day |
BVAS=0 |
FASENRA*
N=70 |
Mepo†
N=70 |
FASENRA*
N=70 |
Mepo†
N=70 |
FASENRA*
N=70 |
Mepo†
N=70 |
| Accrued duration over 52 weeks‡, n (%) |
| 0 weeks§ |
9 (13) |
15 (21) |
9 (13) |
12 (17) |
0 |
0 |
| >0 to <12 weeks |
12 (17) |
10 (14) |
10 (14) |
12 (17) |
0 |
2 (3) |
| 12 to <24 weeks |
8 (11) |
8 (11) |
9 (13) |
8 (11) |
2 (3) |
2 (3) |
| 24 to <36 weeks |
21 (30) |
19 (27) |
19 (27) |
18 (26) |
6 (9) |
7 (10) |
| ≥36 weeks |
20 (29) |
18(26) |
23 (33) |
20 (29) |
62 (89) |
59 (84) |
| Odds ratio¶ (95% CI) |
1.4(0.75, 2.5) |
---- |
1.4(0.74, 2.5) |
---- |
1.5(0.54, 4.2) |
---- |
* FASENRA 30 mg administered subcutaneously every 4 weeks.
† Mepolizumab (Mepo) 300 mg administered subcutaneously every 4 weeks.
‡ Not included in the pre-specified multiple testing procedure for statistical significance.
§ Did not achieve remission at any point.
¶ An odds ratio >1 favors FASENRA. This result was not statistically significant as there was no pre-specified multiple testing procedure. |
Relapse
The hazard ratio for time to first relapse (defined as worsening related to vasculitis, asthma, or sino-nasal symptoms requiring an increase in dose of corticosteroids or immunosuppressive therapy or hospitalization) was 0.98 (95% CI: 0.53, 1.8). Relapse was observed in 30% of patients on FASENRA and 30% of patients on mepolizumab.
The annualized relapse rate was 0.50 for patients receiving FASENRA versus 0.49 for patients receiving mepolizumab (rate ratio 1.0, 95% CI: 0.56, 1.9). The types of relapse were consistent for patients receiving FASENRA or mepolizumab.
Oral Corticosteroid Reduction
During Weeks 48 to 52, a 100% reduction in the OCS dose was observed in 41% of patients receiving FASENRA compared to 26% of those receiving mepolizumab (difference 16%, 95% CI: 0.67, 31). During Weeks 48 to 52, reductions of 50% or higher were observed in 86% of patients receiving FASENRA compared to 74% of those receiving mepolizumab (difference 12%, 95% CI: -0.57, 25). These results were not statistically significant as there was no pre-specified multiple testing procedure.
Asthma Control Questionnaire-6 (ACQ-6)
ACQ-6 is a 6-item questionnaire that is completed by the patient to measure the adequacy of asthma control and change in asthma control. The ACQ-6 responder rate during Weeks 48 to 52 (defined as a decrease in score of 0.5 or more compared with baseline) was 42% for FASENRA and 48% for mepolizumab (difference -6.2%, 95% CI: -19, 6.2).