Clinical Pharmacology for Xolair
Mechanism Of Action
Asthma, Chronic Rhinosinusitis With Nasal Polyps, And IgE-Mediated Food Allergy
Omalizumab inhibits the binding of IgE to the high-affinity IgE receptor (FcεRI) on the surface of mast cells, basophils, and dendritic cells, resulting in FcεRI down-regulation on these cells.
In allergic asthmatics, treatment with omalizumab inhibits IgE-mediated inflammation, as evidenced by reduced blood and tissue eosinophils and reduced inflammatory mediators, including IL-4, IL-5, and IL-13.
Chronic Spontaneous Urticaria
Omalizumab binds to IgE and lowers free IgE levels. Subsequently, IgE receptors (FcεRI) on cells down-regulate. The mechanism by which these effects of omalizumab result in an improvement of chronic spontaneous urticaria (CSU) symptoms is unknown.
Pharmacodynamics
Asthma
In clinical studies, serum free IgE levels were reduced in a dose-dependent manner within 1 hour following the first dose and maintained between doses. Mean serum free IgE decrease was greater than 96% using recommended doses. Serum total IgE levels (i.e., bound and unbound) increased after the first dose due to the formation of omalizumab:IgE complexes, which have a slower elimination rate compared with free IgE. At 16 weeks after the first dose, average serum total IgE levels were five-fold higher compared with pre-treatment when using standard assays. After discontinuation of XOLAIR dosing, the XOLAIR-induced increase in total IgE and decrease in free IgE were reversible, with no observed rebound in IgE levels after drug washout. Total IgE levels did not return to pre-treatment levels for up to one year after discontinuation of XOLAIR.
Chronic Rhinosinusitis With Nasal Polyps
In clinical studies in chronic rhinosinusitis with nasal polyps (CRSwNP) patients, omalizumab treatment led to a reduction in serum free IgE and an increase in serum total IgE levels, similar to the observations in asthma patients. The mean total IgE concentrations at baseline were 168 IU/mL and 218 IU/mL in CRSwNP Trial 1 and 2, respectively. After repeated dosing every 2 or 4 weeks, with dosage and frequency according to Table 3, the mean predose free IgE concentrations at Week 16 were 10.0 IU/mL in CRSwNP Trial 1 and 11.7 IU/mL in CRSwNP Trial 2 and remained stable at 24 weeks of treatment. Total IgE levels in serum increased due to the formation of omalizumab-IgE complexes, which have a slower elimination rate compared with free IgE. After repeated dosing every 2 or 4 weeks, with dosage and frequency according to Table 3, mean and median predose serum total IgE levels at Week 16 were 3- to 4- fold higher compared with pre-treatment levels, and remained stable between 16 and 24 weeks of treatment.
IgE-Mediated Food Allergy
In a clinical study in patients with IgE-mediated food allergy, omalizumab treatment led to a reduction in serum free IgE and an increase in serum total IgE levels, similar to the observations in asthma patients. The mean total IgE concentration at baseline was 810 IU/mL. After repeated dosing every 2 or 4 weeks, with dosage and frequency according to Table 4, the mean pre-dose free IgE concentration at Week 16 was 10.0 IU/mL. Mean total IgE levels in serum increased about 2.4-fold due to the formation of omalizumab-IgE complexes, which have a longer half-life compared with free IgE.
Chronic Spontaneous Urticaria
In clinical studies in chronic spontaneous urticaria (CSU) patients, XOLAIR treatment led to a dose-dependent reduction of serum free IgE and an increase of serum total IgE levels, similar to the observations in asthma patients. Maximum suppression of free IgE was observed 3 days following the first subcutaneous dose. After repeat dosing once every 4 weeks, predose serum free IgE levels remained stable between 12 and 24 weeks of treatment. Total IgE levels in serum increased after the first dose due to the formation of omalizumab- IgE complexes which have a slower elimination rate compared with free IgE. After repeat dosing once every 4 weeks at 75 mg up to 300 mg, average predose serum total IgE levels at Week 12 were two- to three-fold higher compared with pre-treatment levels, and remained stable between 12 and 24 weeks of treatment. After discontinuation of XOLAIR dosing, free
IgE levels increased and total IgE levels decreased towards pre-treatment levels over a 16- week follow-up period.
Pharmacokinetics
After SC administration, omalizumab was absorbed with an average absolute bioavailability of 62%. Following a single SC dose in adult and adolescent patients with asthma, omalizumab was absorbed slowly, reaching peak serum concentrations after an average of 7– 8 days. In patients with CSU, the peak serum concentration was reached at a similar time after a single SC dose. The pharmacokinetics of omalizumab was linear at doses greater than 0.5 mg/kg. In patients with asthma, following multiple doses of XOLAIR, areas under the serum concentration-time curve from Day 0 to Day 14 at steady state were up to 6-fold of those after the first dose. In patients with CSU, omalizumab exhibited linear pharmacokinetics across the dose range of 75 mg to 600 mg given as single subcutaneous dose. Following repeat dosing from 75 to 300 mg every 4 weeks, trough serum concentrations of omalizumab increased proportionally with the dose levels.
In in vitro, omalizumab formed complexes of limited size with IgE. Precipitating complexes and complexes larger than 1 million daltons in molecular weight were not observed in in vitro or in vivo. Tissue distribution studies in Cynomolgus monkeys showed no specific uptake of 125I-omalizumab by any organ or tissue. The apparent volume of distribution of omalizumab in patients with asthma following SC administration was 78 ± 32 mL/kg. In patients with CSU, based on population pharmacokinetics, distribution of omalizumab was similar to that in patients with asthma.
Clearance of omalizumab involved IgG clearance processes as well as clearance via specific binding and complex formation with its target ligand, IgE. Liver elimination of IgG included degradation in the liver reticuloendothelial system (RES) and endothelial cells. Intact IgG was also excreted in bile. In studies with mice and monkeys, omalizumab:IgE complexes were eliminated by interactions with Fcγ receptors within the RES at rates that were generally faster than IgG clearance. In asthma patients omalizumab serum elimination half-life averaged 26 days, with apparent clearance averaging 2.4 ± 1.1 mL/kg/day.
Doubling body weight approximately doubled apparent clearance. In CSU patients, at steady state, based on population pharmacokinetics, omalizumab serum elimination half-life averaged 24 days and apparent clearance averaged 240 mL/day (corresponding to 3.0 mL/kg/day for an 80 kg patient).
Specific Populations
Asthma
The population pharmacokinetics of omalizumab was analyzed to evaluate the effects of demographic characteristics in patients with asthma. Analyses of these data suggested that no dose adjustments are necessary for age (6 to 76 years), race, ethnicity, or gender.
Chronic Rhinosinusitis With Nasal Polyps
The population pharmacokinetics analyses of omalizumab suggested that the pharmacokinetics of omalizumab in chronic rhinosinusitis with nasal polyps (CRSwNP) were consistent with that in asthma. Graphical covariate analyses were performed to evaluate the effects of demographic characteristics and other factors on omalizumab exposure and clinical responses. These analyses demonstrate that no dose adjustments are necessary for age (18 to 75 years) or gender. Race and ethnicity data are too limited in CRSwNP studies to inform dose adjustment.
IgE-Mediated Food Allergy
Population pharmacokinetic (PK) analyses of omalizumab suggested that the PK of omalizumab in patients with IgE-mediated food allergy were generally consistent with that in patients with asthma. Covariate analyses were performed to evaluate the effects of demographic characteristics and other factors on omalizumab exposure and clinical responses. These analyses demonstrate that no dose adjustments are necessary for age (1 year and older), race, ethnicity, or gender.
Chronic Spontaneous Urticaria
The population pharmacokinetics of omalizumab was analyzed to evaluate the effects of demographic characteristics and other factors on omalizumab exposure in patients with chronic spontaneous urticaria (CSU). Covariate effects were evaluated by analyzing the relationship between omalizumab concentrations and clinical responses. These analyses demonstrate that no dose adjustments are necessary for age (12 to 75 years), race/ethnicity, gender, body weight, body mass index, or baseline IgE level.
Immunogenicity
The observed incidence of anti-drug antibodies is highly dependent on the sensitivity and specificity of the assay. Differences in assay methods preclude meaningful comparisons of the incidence of anti-drug antibodies in the studies described below with the incidence of anti-drug antibodies in other studies, including those of XOLAIR or of other omalizumab products.
Antibodies to XOLAIR were detected in approximately 1/1723 (<0.1%) of patients treated with XOLAIR in the clinical studies evaluated for asthma in patients 12 years of age and older. In three pediatric studies, antibodies to XOLAIR were detected in one patient out of 581 patients 6 to <12 years of age treated with XOLAIR and evaluated for antibodies. There were no detectable antibodies in the patients treated in the CSU clinical trials, but due to levels of XOLAIR at the time of anti-therapeutic antibody sampling and missing samples for some patients, antibodies to XOLAIR could only have been determined in 88% of the 733 patients treated in these clinical studies. The data reflect the percentage of patients whose test results were considered positive for antibodies to XOLAIR in ELISA assays and are highly dependent on the sensitivity and specificity of the assays.
Anti-drug antibodies were not measured in the CRSwNP or IgE-mediated food allergy trials.
Clinical Studies
Asthma
Adult and Adolescent Patients 12 Years of Age and Older
The safety and efficacy of XOLAIR were evaluated in three randomized, double-blind, placebo-controlled, multicenter trials.
The trials enrolled patients 12 to 76 years old, with moderate to severe persistent (NHLBI criteria) asthma for at least one year, and a positive skin test reaction to a perennial aeroallergen. In all trials, XOLAIR dosing was based on body weight and baseline serum total IgE concentration. All patients were required to have a baseline IgE between 30 and 700 IU/mL and body weight not more than 150 kg. Patients were treated according to a dosing table to administer at least 0.016 mg/kg/IU (IgE/mL) of XOLAIR or a matching volume of placebo over each 4-week period. The maximum XOLAIR dose per 4 weeks was 750 mg.
In all three trials an exacerbation was defined as a worsening of asthma that required treatment with systemic corticosteroids or a doubling of the baseline ICS dose. Most exacerbations were managed in the outpatient setting and the majority were treated with systemic steroids. Hospitalization rates were not significantly different between XOLAIR and placebo-treated patients; however, the overall hospitalization rate was small. Among those patients who experienced an exacerbation, the distribution of exacerbation severity was similar between treatment groups.
Asthma Trials 1 And 2
At screening, patients in Asthma Trials 1 and 2 had a forced expiratory volume in one second (FEV1) between 40% and 80% predicted. All patients had a FEV1 improvement of at least 12% following beta2-agonist administration. All patients were symptomatic and were being treated with inhaled corticosteroids (ICS) and short-acting beta2-agonists. Patients receiving other concomitant controller medications were excluded, and initiation of additional controller medications while on study was prohibited. Patients currently smoking were excluded.
Each trial was comprised of a run-in period to achieve a stable conversion to a common ICS (beclomethasone dipropionate), followed by randomization to XOLAIR or placebo. Patients received XOLAIR for 16 weeks with an unchanged corticosteroid dose unless an acute exacerbation necessitated an increase. Patients then entered an ICS reduction phase of 12 weeks during which ICS dose reduction was attempted in a step-wise manner.
The distribution of the number of asthma exacerbations per patient in each group during a study was analyzed separately for the stable steroid and steroid-reduction periods.
In both Asthma Trials 1 and 2 the number of exacerbations per patient was reduced in patients treated with XOLAIR compared with placebo (Table 11).
Measures of airflow (FEV1) and asthma symptoms were also evaluated in these trials. The clinical relevance of the treatment-associated differences is unknown. Results from the stable steroid phase Asthma Trial 1 are shown in Table 12. Results from the stable steroid phase of Asthma Trial 2 and the steroid reduction phases of both Asthma Trials 1 and 2 were similar to those presented in Table 12.
Table 11. Frequency of Asthma Exacerbations per Patient by Phase in Asthma Trials 1 and 2
|
Stable Steroid Phase (16 wks) |
|
Asthma Trial 1 |
Asthma Trial 2 |
| Exacerbations per patient |
XOLAIR
N=268 |
Placebo
N=257 |
XOLAIR
N=274 |
Placebo
N=272 |
| 0 |
85.8% |
76.7% |
87.6% |
69.9% |
| 1 |
11.9% |
16.7% |
11.3% |
25.0% |
| ≥2 |
2.2% |
6.6% |
1.1% |
5.1% |
| p-Value |
0.005 |
<0.001 |
| Mean number exacerbations/patient |
0.2 |
0.3 |
0.1 |
0.4 |
|
Steroid Reduction Phase (12 wks) |
Exacerbations per
patient |
XOLAIR
N=268 |
Placebo
N=257 |
XOLAIR
N=274 |
Placebo
N=272 |
| 0 |
78.7% |
67.7% |
83.9% |
70.2% |
| 1 |
19.0% |
28.4% |
14.2% |
26.1% |
| ≥2 |
2.2% |
3.9% |
1.8% |
3.7% |
| p-Value |
0.004 |
<0.001 |
| Mean number exacerbations/patient |
0.2 |
0.4 |
0.2 |
0.3 |
Table 12. Asthma Symptoms and Pulmonary Function During Stable Steroid Phase of Asthma Trial 1
| Endpoint |
XOLAIR
N=268* |
Placebo
N=257* |
| Mean Baseline |
Median Change (Baseline to Wk 16) |
Mean Baseline |
Median Change (Baseline to Wk 16) |
| Total asthma symptom score |
4.3 |
–1.5† |
4.2 |
–1.1† |
| Nocturnal asthma score |
1.2 |
–0.4† |
1.1 |
–0.2† |
| Daytime asthma score |
2.3 |
–0.9† |
2.3 |
–0.6† |
| FEV1 % predicted |
68 |
3† |
68 |
0† |
Asthma symptom scale: total score from 0 (least) to 9 (most); nocturnal and daytime scores from 0 (least) to 4 (most symptoms).
* Number of patients available for analysis ranges 255-258 in the XOLAIR group and 238-239 in the placebo group.
† Comparison of XOLAIR versus placebo (p < 0.05). |
Asthma Trial 3
In Asthma Trial 3, there was no restriction on screening FEV1, and unlike Asthma Trials 1 and 2, long-acting beta2-agonists were allowed. Patients were receiving at least 1000 μg/day fluticasone propionate and a subset was also receiving oral corticosteroids. Patients receiving other concomitant controller medications were excluded, and initiation of additional controller medications while on study was prohibited. Patients currently smoking were excluded.
The trial was comprised of a run-in period to achieve a stable conversion to a common ICS (fluticasone propionate), followed by randomization to XOLAIR or placebo. Patients were stratified by use of ICS-only or ICS with concomitant use of oral steroids. Patients received XOLAIR for 16 weeks with an unchanged corticosteroid dose unless an acute exacerbation necessitated an increase. Patients then entered an ICS reduction phase of 16 weeks during which ICS or oral steroid dose reduction was attempted in a step-wise manner.
The number of exacerbations in patients treated with XOLAIR was similar to that in placebotreated patients (Table 13). The absence of an observed treatment effect may be related to differences in the patient population compared with Asthma Trials 1 and 2, study sample size, or other factors.
Table 13. Percentage of Patients with Asthma Exacerbations by Subgroup and Phase in Asthma Trial 3
|
Stable Steroid Phase (16 wks) |
| Inhaled Only |
Oral + Inhaled |
| XOLAIR N=126 |
Placebo N=120 |
XOLAIR N=50 |
Placebo N=45 |
| % Patients with ≥1 exacerbations |
15.9% |
15.0% |
32.0% |
22.2% |
Difference
(95% CI) |
0.9
(–9.7, 13.7) |
9.8
(–10.5, 31.4) |
|
Steroid Reduction Phase (16 wks) |
|
XOLAIR N=126 |
Placebo N=120 |
XOLAIR N=50 |
Placebo N=45 |
| % Patients with ≥1 exacerbations |
22.2% |
26.7% |
42.0% |
42.2% |
Difference
(95% CI) |
–4.4
(–17.6, 7.4) |
–0.2
(–22.4, 20.1) |
In all three of the trials, a reduction of asthma exacerbations was not observed in the XOLAIR-treated patients who had FEV1>80% at the time of randomization. Reductions in exacerbations were not seen in patients who required oral steroids as maintenance therapy.
Pediatric Patients 6 To <12 Years Of Age
The safety and efficacy of XOLAIR in pediatric patients 6 to <12 years of age with moderate to severe asthma is based on one randomized, double-blind, placebo controlled, multi-center trial (Asthma Trial 4 [NCT00079937]) and an additional supportive study (Asthma Trial 5).
Asthma Trial 4 was a 52-week study that evaluated the safety and efficacy of XOLAIR as add-on therapy in 628 pediatric patients ages 6 to <12 years with moderate to severe asthma inadequately controlled despite the use of inhaled corticosteroids (fluticasone propionate DPI ≥200 mcg/day or equivalent) with or without other controller asthma medications. Eligible patients were those with a diagnosis of asthma >1 year, a positive skin prick test to at least one perennial aeroallergen, and a history of clinical features such as daytime and/or nighttime symptoms and exacerbations within the year prior to study entry. During the first 24 weeks of treatment, steroid doses remained constant from baseline. This was followed by a 28-week period during which inhaled corticosteroid adjustment was allowed.
The primary efficacy variable was the rate of asthma exacerbations during the 24-week, fixed steroid treatment phase. An asthma exacerbation was defined as a worsening of asthma symptoms as judged clinically by the investigator, requiring doubling of the baseline inhaled corticosteroid dose for at least 3 days and/or treatment with rescue systemic (oral or IV) corticosteroids for at least 3 days. At 24 weeks, the XOLAIR group had a statistically significantly lower rate of asthma exacerbations (0.45 vs. 0.64) with an estimated rate ratio of 0.69 (95% CI: 0.53, 0.90).
The XOLAIR group also had a lower rate of asthma exacerbations compared to placebo over the full 52-week double-blind treatment period (0.78 vs. 1.36; rate ratio: 0.57; 95% CI: 0.45, 0.72). Other efficacy variables such as nocturnal symptom scores, beta-agonist use, and measures of airflow (FEV1) were not significantly different in XOLAIR-treated patients compared to placebo.
Asthma Trial 5 was a 28-week randomized, double blind, placebo-controlled study that primarily evaluated safety in 334 pediatric patients, 298 of whom were 6 to <12 years of age, with moderate to severe asthma who were well-controlled with inhaled corticosteroids (beclomethasone dipropionate 168-420 mcg/day). A 16-week steroid treatment period was followed by a 12-week steroid dose reduction period. Patients treated with XOLAIR had fewer asthma exacerbations compared to placebo during both the 16-week fixed steroid treatment period (0.18 vs. 0.32; rate ratio: 0.58; 95% CI: 0.35, 0.96) and the 28-week treatment period (0.38 vs. 0.76; rate ratio: 0.50; 95% CI: 0.36, 0.71).
Chronic Rhinosinusitis With Nasal Polyps
Adult Patients 18 Years Of Age And Older
The safety and efficacy of XOLAIR was evaluated in two, randomized, multicenter, doubleblind, placebo-controlled clinical trials (CRSwNP Trial 1 [NCT03280550] and CRSwNP Trial 2 [NCT03280537]) that enrolled patients with chronic rhinosinusitis with nasal polyps (CRSwNP) with inadequate response to nasal corticosteroids (CRSwNP Trial 1, n=138; CRSwNP Trial 2, n=127). Patients received XOLAIR or placebo SC every 2 or 4 weeks, with XOLAIR dosage and frequency according to Table 3, for 24 weeks followed by a 4- week follow-up period. All patients received background nasal mometasone therapy during both the treatment period and during a 5-week run-in period. Prior to randomization, patients were required to have evidence of bilateral polyps as determined by a nasal polyp score (NPS) ≥ 5 with NPS ≥ 2 in each nostril, despite use of nasal mometasone during the run-in period. NPS was measured via endoscopy and scored (range 0-4 per nostril: 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; 4=large polyps causing complete obstruction of the inferior nasal cavity) for a total NPS (range 0-8). Patients were furthermore required to have a weekly average of nasal congestion score (NCS) > 1 prior to randomization, despite use of nasal mometasone. Nasal congestion was measured by a daily assessment on a 0 to 3 point severity scale (0=none, 1=mild, 2=moderate, 3=severe). Prior sino-nasal surgery or prior systemic corticosteroid usage were not required for inclusion in the trials and sinus CT scans were not performed to evaluate for sinus opacification. Demographics and baseline characteristics, including allergic comorbidities, are described in Table 14.
Table 14. Demographics and Baseline Characteristics of CRSwNP Trials 1 and 2
| Parameter |
CRSwNP Trial 1
(n=138) |
CRSwNP Trial 2
(n=127) |
| Mean age (years) (SD) |
51 (13) |
50 (12) |
| % Male |
64 |
65 |
| Patients with systemic corticosteroid use in the previous year (%) |
19 |
26 |
| Patients with prior surgery for nasal polyps (%) |
79 (57) |
79 (62) |
| Mean bilateral endoscopic NPS (SD), range 0-8 |
6.2 (1.0) |
6.3 (0.9) |
| Mean nasal congestion score (SD) range 0-3 |
2.4 (0.6) |
2.3 (0.7) |
| Mean sense of smell score (SD) range 0-3 |
2.7 (0.7) |
2.7 (0.7) |
| Mean post nasal drip score (SD) range 0-3 |
1.8 (0.9) |
1.7 (0.9) |
| Mean runny nose score (SD) range 0-3 |
2.0 (0.8) |
1.9 (0.9) |
| Mean blood eosinophils (cells/mcL) (SD) |
346 (284) |
335 (188) |
| Mean total IgE IU/mL (SD) |
161 (140) |
190 (201) |
| Asthma (%) |
54 |
61 |
| Aspirin exacerbated respiratory disease (%) |
20 |
35 |
| CRSwNP= chronic rhinosinusitis with nasal polyps; SD=standard deviation; NPS=nasal polyp score; IgE = Immunoglobulin E; IU=international units. For NPS, NCS, sense of smell, post nasal drip, and runny nose, higher scores indicate greater disease severity. |
The co-primary endpoints in CRSwNP Trials 1 and 2 were NPS and average daily NCS at Week 24. In both trials, patients who received XOLAIR had a statistically significant greater improvement from baseline at Week 24 in NPS and weekly average NCS, than patients who received placebo. Results from CRSwNP Trials 1 and 2 are shown in Table 15.
The greater improvements in NPS and NCS in the XOLAIR group compared to the placebo group were observed as early as the first assessment at Week 4 in both studies, as seen in Figure 1.
Table 15. Change from Baseline at Week 24 in Nasal Polyp Score and 7-day Average of Daily Nasal Congestion Score in CRSwNP Trials 1 and 2
|
Trial 1 |
Trial 2 |
| Placebo |
XOLAIR |
Placebo |
XOLAIR |
| Number of patients |
65 |
72 |
65 |
62 |
| Nasal Polyp Score |
| Mean Baseline Score |
6.3 |
6.2 |
6.1 |
6.4 |
| LS Mean Change From Baseline at Week 24 |
0.1 |
-1.1 |
-0.3 |
-0.9 |
| Difference in LS means vs. placebo |
-1.1 |
-0.6 |
95% CI for difference
p-value |
-1.6, -0.7
<0.0001 |
-1.1, -0.1
0.0140 |
| 7-day Average of Daily Nasal Congestion Score |
| Mean Baseline Score |
2.5 |
2.4 |
2.3 |
2.3 |
| LS Mean Change From Baseline at Week 24 |
-0.4 |
-0.9 |
-0.2 |
-0.7 |
| Difference in LS means vs. placebo |
-0.6 |
-0.5 |
95% CI for difference
p-value |
-0.8, -0.3
0.0004 |
-0.8, -0.2
0.0017 |
| CRSwNP= chronic rhinosinusitis with nasal polyps; LS=least-square. Change from baseline was analyzed using a mixed-effect model of repeated measures (MMRM) model with baseline score, baseline score/timepoint (week) interaction as covariates, and the following factors: geographic region, asthma/aspirin sensitivity comorbidity status, timepoint, treatment group, treatment/timepoint interaction. |
The mean NPS and NCS at each study week by treatment group is shown in Figure 1.
Figure 1. Mean Change from Baseline in Nasal Congestion Score and Mean Change from Baseline in Nasal Polyp Score by Treatment Group in CRSwNP Trials 1 and 2
XOLAIR had statistically significant improvements on sense of smell score compared to placebo. Sense of smell was measured by a daily assessment on a 0 to 3 point severity scale (0=no symptoms, 1=mild symptoms, 2=moderate symptoms, 3=severe symptoms). The LS mean difference for change from baseline at Week 24 in sense of smell score in XOLAIR compared to placebo was -0.3 (95% CI: -0.6, -0.1) in CRSwNP Trial 1 and -0.5 (95% CI: - 0.7, -0.2) in CRSwNP Trial 2.
XOLAIR had statistically significant improvements on post-nasal drip compared to placebo. The LS mean difference for change from baseline at Week 24 in post-nasal drip score in XOLAIR compared to placebo was -0.6 (95% CI: -0.8, -0.3) in CRSwNP Trial 1 and -0.5 (95% CI: -0.8, -0.3) in CRSwNP Trial 2.
XOLAIR had statistically significant improvements on runny nose compared to placebo.
The LS mean difference for change from baseline at Week 24 in runny nose score in XOLAIR compared to placebo was -0.4 (95% CI: -0.7, -0.2) in CRSwNP Trial 1 and -0.6 (95% CI: -0.9, -0.4) in CRSwNP Trial 2.
In a pre-specified pooled analysis of systemic corticosteroid use during the 24-week treatment period, there was no significant reduction in systemic corticosteroid use between the treatment arms. The proportion of patients taking systemic corticosteroid in XOLAIR was 2.3% compared to 6.2% in placebo. The odds-ratio of systemic corticosteroid use with XOLAIR compared to placebo was 0.4 (95% CI: 0.1, 1.5).
There were no sino-nasal surgeries reported, in either placebo or XOLAIR arms, in either Trial.
IgE-Mediated Food Allergy
The safety and efficacy of XOLAIR was evaluated in a multi-center, randomized, doubleblind, placebo-controlled Food Allergy (FA) trial [NCT03881696] in 168 adult patients and pediatric patients 1 year of age to less than 56 years who were allergic to peanut and at least two other foods, including milk, egg, wheat, cashew, hazelnut, or walnut (i.e., studied foods). The FA trial enrolled patients who experienced dose-limiting symptoms (e.g., moderate to severe skin, respiratory or gastrointestinal symptoms) to a single dose of ≤100 mg of peanut protein and ≤300 mg protein for each of the other two foods (milk, egg, wheat, cashew, hazelnut, or walnut) during the screening double-blind placebo-controlled food challenge (DBPCFC). Patients with a history of severe anaphylaxis (defined as neurological compromise or requiring intubation) were excluded from the study. Patients were randomized 2:1 to receive a subcutaneous dosage of XOLAIR or placebo based on serum total IgE level (IU/mL), measured before the start of treatment, and by body weight according to Table 4 [see DOSAGE AND ADMINISTRATION] for 16 to 20 weeks. After 16 to 20 weeks of treatment, each patient completed a DBPCFC consisting of placebo and each of their 3 studied foods. Following the DBPCFC, the first 60 patients that included 59 pediatric patients and one adult patient who completed the double-blind, placebo-controlled phase of the study could continue to receive XOLAIR in a 24 to 28 week open-label extension.
Efficacy of XOLAIR is based on 165 pediatric patients who were included in the efficacy analyses provided below. The mean age of the pediatric patients was 8 years (age range: 1 to 17 years); 37% were less than 6 years of age, 38% were 6 to less than 12 years of age, and 25% were 12 to less than 18 years of age. Patient population were 56% male, 63% White, 13% Asian, 7% Black, 16% Other, and 55% of patients had a history of asthma.
The primary efficacy endpoint was the percentage of patients who were able to consume a single dose of ≥600 mg of peanut protein without dose-limiting symptoms (e.g., moderate to severe skin, respiratory or gastrointestinal symptoms) during DBPCFC. Table 16 shows XOLAIR treatment led to a statistically higher response rate (68%) than placebo (5%).
The secondary efficacy endpoints were the percentage of patients who were able to consume a single dose of ≥1000 mg of cashew, milk, or egg protein without dose-limiting symptoms during DBPCFC. The study met the secondary endpoints and demonstrated that XOLAIR treatment led to statistically higher response rates than placebo for all three foods. See Table 16 for details.
Table 16. DBPCFC Response Rates in Pediatric Patients for Single Dose of Peanut, Cashew, Milk or Egg Protein in FA Trial
| Food, Challenge Dose |
Response Ratea (%) (n/N) |
Treatment Difference (%) (XOLAIR-Placebo) (95% CI) |
| XOLAIR |
Placebo |
| Peanut, ≥600 mg |
68%
(75/110) |
5%
(3/55) |
63%
(50%, 73%) |
| Peanut, ≥1000 mgb |
65%
(72/110) |
0%
(0/55) |
65%
(56%, 74%) |
| Cashew, ≥1000 mg |
42%
(27/64) |
3%
(1/30) |
39%
(20%, 53%) |
| Milk, ≥1000 mg |
66%
(25/38) |
11%
(2/19) |
55%
(29%, 73%) |
| Egg, ≥1000 mg |
67%
(31/46) |
0%
(0/19) |
67%
(49%, 80%) |
CI = Confidence interval; DBPCFC = Double-blind placebo-controlled food challenge; n = Number of responders; N = Total number of patients receiving food, challenge dose.
a Response defined as consumption of a single dose of the specified amount of food without dose-limiting symptoms.
b Consumption of a single dose of ≥1000 mg of peanut protein was an additional secondary endpoint. The key secondary efficacy endpoints were the percentage of patients who were able to consume a single dose of ≥1000 mg of cashew, milk, or egg protein.
Notes: Subjects without an exit DBPCFC or evaluable exit DBPCFC were counted as non-responders; P-values from two-sided Fisher’s exact tests were <0.0001 for all the food challenge doses. |
Seventeen percent of XOLAIR treated patients were not able to consume >100 mg of peanut protein without moderate to severe dose-limiting symptoms. Eighteen, 22, and 41 percent of XOLAIR-treated patients were not able to consume >300 mg of milk, egg, or cashew protein, respectively, without moderate to severe dose-limiting symptoms.
Additional secondary analyses included the percentage of patients who were able to consume at least two or all three foods during DBPCFC. For two foods, 71% of XOLAIR treated patients were able to consume a single dose of ≥600 mg versus 5% in the placebo group and 67% were able to consume a single dose of ≥1000 mg versus 4% in the placebo group. For a single dose of ≥600 mg of three foods, the response rates were 48% in the XOLAIR group versus 4% in the placebo group and for a single dose of ≥1000 mg of three foods, the response rate in the XOLAIR group was 39% while none of the placebo patients were able to consume the challenge dose without symptoms.
The effectiveness of XOLAIR in adults is supported by the adequate and well-controlled trial of XOLAIR in pediatric patients, disease similarity in pediatric and adult patients, and pharmacokinetic (PK) similarity [see CLINICAL PHARMACOLOGY].
While efficacy cannot be established from uncontrolled, open-label studies, for 38 pediatric patients who continued XOLAIR for 24-28 weeks in an open-label extension, the percentage of patients who were able to consume ≥600 mg of peanut protein and ≥1000 mg of egg, milk, and/or cashew protein without moderate to severe dose-limiting symptoms was maintained.
Chronic Spontaneous Urticaria
Adult And Adolescent Patients 12 Years Of Age And Older
The safety and efficacy of XOLAIR for the treatment of chronic spontaneous urticaria (CSU), previously referred to as chronic idiopathic urticaria (CIU) was assessed in two placebo-controlled, multiple-dose clinical trials of 24 weeks’ duration (CSU Trial 1; n= 319, [NCT01287117]) and 12 weeks’ duration (CSU Trial 2; n=322, [NCT01292473]). Patients received XOLAIR 75 mg, 150 mg, or 300 mg or placebo by SC injection every 4 weeks in addition to their baseline level of H1 antihistamine therapy for 24 or 12 weeks, followed by a 16-week washout observation period. A total of 640 patients (165 males, 475 females) were included for the efficacy analyses. Most patients were white (84%) and the median age was 42 years (range 12–72).
Disease severity was measured by a weekly urticaria activity score (UAS7, range 0–42), which is a composite of the weekly itch severity score (range 0–21) and the weekly hive count score (range 0–21). All patients were required to have a UAS7 of ≥16, and a weekly itch severity score of ≥8 for the 7 days prior to randomization, despite having used an H1 antihistamine for at least 2 weeks.
The mean weekly itch severity scores at baseline were fairly balanced across treatment groups and ranged between 13.7 and 14.5 despite use of an H1 antihistamine at an approved dose. The reported median durations of CSU at enrollment across treatment groups were between 2.5 and 3.9 years (with an overall subject-level range of 0.5 to 66.4 years).
In both CSU Trials 1 and 2, patients who received XOLAIR 150 mg or 300 mg had greater decreases from baseline in weekly itch severity scores and weekly hive count scores than placebo at Week 12. Representative results from CSU Trial 1 are shown (Table 17); similar results were observed in CSU Trial 2. The 75-mg dose did not demonstrate consistent evidence of efficacy and is not approved for use.
Table 17. Change from Baseline to Week 12 in Weekly Itch Severity Score and Weekly Hive Count Score in CSU Trial 1*
|
XOLAIR
75mg |
XOLAIR
150mg |
XOLAIR
300mg |
Placebo |
| n |
77 |
80 |
81 |
80 |
| Weekly Itch Severity Score |
| Mean Baseline Score (SD) |
14.5 (3.6) |
14.1 (3.8) |
14.2 (3.3) |
14.4 (3.5) |
| Mean Change Week 12 (SD) |
−6.46 (6.14) |
−6.66 (6.28) |
−9.40 (5.73) |
−3.63 (5.22) |
| Difference in LS means vs. placebo |
−2.96 |
−2.95 |
−5.80 |
- |
| 95% CI for difference |
−4.71, −1.21 |
−4.72, −1.18 |
−7.49, −4.10 |
- |
| Weekly Hive Count Score † |
| Mean Baseline Score (SD) |
17.2 (4.2) |
16.2 (4.6) |
17.1 (3.8) |
16.7 (4.4) |
| Mean Change Week 12 (SD) |
−7.36 (7.52) |
−7.78 (7.08) |
−11.35 (7.25) |
−4.37 (6.60) |
| Difference in LS means vs. placebo |
−2.75 |
−3.44 |
−6.93 |
- |
| 95% CI for difference |
−4.95, −0.54 |
−5.57, −1.32 |
−9.10, −4.76 |
- |
* Modified intent-to-treat (mITT) population: all patients who were randomized and received at least one
dose of study medication.
† Score measured on a range of 0–21 |
The mean weekly itch severity score at each study week by treatment groups is shown in Figure 2. Representative results from CSU Trial 1 are shown; similar results were observed in CSU Trial 2. The appropriate duration of therapy for CSU with XOLAIR has not been determined.
Figure 2. Mean Weekly Itch Severity Score by Treatment Group Modified Intent to Treat Patients in CSU Trial 1
In CSU Trial 1, a larger proportion of patients treated with XOLAIR 300 mg (36%) reported no itch and no hives (UAS7=0) at Week 12 compared to patients treated with XOLAIR 150 mg (15%), XOLAIR 75 mg (12%), and placebo group (9%). Similar results were observed in CSU Trial 2.