The efficacy of ODACTRA for the treatment of HDM-induced allergic rhinitis was investigated in two double-blind, placebo-controlled, randomized clinical field efficacy studies (Studies 1 and 2) and one environmental exposure chamber (EEC) study.
Study 1 (North American Field Efficacy Study)
Study 1 was a double-blind, placebo-controlled, randomized field efficacy study conducted in the United States and Canada for a duration of up to 12 months, that compared the efficacy of ODACTRA (N=741) compared to placebo (N=741) in the treatment of HDM-induced allergic rhinitis. Subjects 12 through 85 years of age were enrolled if they had a history of symptomatic allergic rhinitis and were sensitized to D. farinae and/or D. pteronyssinus as determined by house dust mite specific IgE. Subjects were required to be symptomatic and were not taking symptom-relieving allergy medications at enrollment.
Subjects with mild to moderate asthma, defined as asthma of a severity that required, at most, a daily medium dose of an inhaled corticosteroid, were enrolled in the study.
In this study, 31% of subjects had asthma, 48% had conjunctivitis, and 76% were polysensitized to other allergens in addition to HDM, including trees, grasses, weed, animal danders and molds. The subject population was 76% White, 11% African American, 7% Asian, and 59% female. The mean age of subjects was 35 years.
The efficacy of ODACTRA in the treatment of HDM-induced allergic rhinitis was assessed through self-reporting of symptoms and medication use. Based on these self-assessments, the Total Combined Rhinitis Score (TCRS), daily symptom scores (DSS) and daily medication scores (DMS) for rhinoconjunctivitis were calculated. Daily symptoms included four nasal symptoms (runny nose, stuffy nose, sneezing, and itchy nose) and two ocular symptoms (gritty/itchy eyes and watery eyes). Each of these rhinoconjunctivitis symptoms was individually graded by subjects daily on a scale of 0 (none) to 3 (severe) and then summed. Subjects in active and placebo arms of this study were allowed to take symptom-relieving allergy medications (including oral and ocular antihistamines and nasal corticosteroids) during the study as needed. The DMS measured the use of these standard symptom-relieving allergy medications. Predefined daily maximum scores were assigned to each class of rhinitis and conjunctivitis medication as 0=none, 6=oral antihistamine, 6=ocular antihistamine, and 8=nasal corticosteroid.
The primary endpoint was the difference between the treatment and placebo groups in the average TCRS during approximately the last 8 weeks of treatment. The TCRS represents the sum of the daily rhinitis DSS and the rhinitis DMS. Other secondary endpoints in this study included the average rhinitis DSS, the average rhinitis DMS, and the Total Combined Score (TCS). The TCS represents the sum of the rhinoconjunctivitis DSS and the rhinoconjunctivitis DMS, which was then averaged during approximately the last 8 weeks of treatment.
Subjects in this study were required to stop taking symptom-relieving allergy medication during the baseline period. The mean rhinitis DSS at baseline was 7.94 out of 12 total points in both the treatment arm and in the placebo arm. The results of this study are shown in Table 2.
Table 2: Total Combined Rhinitis Score (TCRS), Rhinitis Daily Symptom Score (DSS), Rhinitis Daily Medication Score (DMS), and Total Combined Score (TCS) During the Last 8 Weeks of Treatment with ODACTRA in Subjects 12 Years of Age and Older (Study 1, Field Efficacy Study) (NCT: NCT01700192)
| Endpoint* | ODACTRA (n=566)† Score‡ | Placebo (n=620)† Score‡ | Treatment Difference (ODACTRA- Placebo) | Difference Relative to Placebo§ |
| | | | Estimate | (95% CI) |
| Primary Endpoint |
| TCRS¶ | 4.10 | 4.95 | -0.80 | -17.2% | (-25.0%, -9.7%) |
| Secondary Endpoints |
| Rhinitis DSS | 3.55 | 4.20 | -0.60 | -15.5% | (-24.4%, -7.3%) |
| Rhinitis DMS | 0.65 | 0.79 | -0.15 | -18.4% | (-41.0%, 4.3%) |
| TCS | 5.50 | 6.60 | -1.10 | -16.7% | (-24.6%, -4.0%) |
TCRS=Total Combined Rhinitis Score (Rhinitis DSS + Rhinitis DMS); TCS=Total Combined Score (Rhinoconjunctivitis DSS + Rhinoconjunctivitis DMS); CI=Confidence Interval
Analyses were based on the full analysis set (FAS), which included all randomized and treated subjects. Subjects were analyzed according to the treatment group to which they were randomized.
*Non-parametric analysis for TCRS, Rhinitis DSS, and TCS endpoints; Parametric analysis using zero-inflated log-normal model for Rhinitis DMS endpoint.
†Number of subjects in analyses.
‡For TCRS, Rhinitis DSS, and TCS endpoints, the estimated group medians are reported. Treatment difference and that relative to placebo is based on estimated group medians. For Rhinitis DMS, the estimated group means are reported. Treatment difference and that relative to placebo is based on estimated group means.
§Difference relative to placebo computed as: (ODACTRA – placebo)/placebo x 100.
¶The pre-specified criteria for demonstration of efficacy was defined as a TCRS difference relative to placebo less than or equal to -15 percent, and the upper bound of the 95 percent confidence interval (CI) of TCRS difference relative to placebo less than or equal to -10 percent.
Study 2 (European Field Efficacy Study)
This double-blind, placebo-controlled, randomized field efficacy study evaluated adult subjects 18 through 66 years of age comparing ODACTRA (N=318) and placebo (N=338) administered as a sublingual tablet daily for a duration of approximately 12 months. Subjects in this study had a history of symptomatic allergic rhinitis when exposed to house dust and were sensitized to D. farinae and/or D. pteronyssinus as determined by house dust mite specific IgE testing. At study entry, subjects were required to be symptomatic despite taking symptom-relieving allergy medications during the baseline period.
In this study, 46% of subjects had asthma, 97% had conjunctivitis and 67% were polysensitized to other allergens in addition to HDM, including trees, grass, weeds, animal danders and molds. The study population was 98% White, <1% African American, and <1% Asian; 50% of subjects were female. The mean age of subjects in this study was 32 years. The primary efficacy endpoint was the difference relative to placebo in the average TCRS during the last 8 weeks of treatment. The mean Rhinitis DSS at baseline was 7.95 out of 12 for the treatment arm and 8.00 out of 12 total points for the placebo arm. The results of this study are shown in Table 3.
Table 3: Total Combined Rhinitis Score (TCRS), Rhinitis Daily Symptom Score (DSS), Rhinitis Daily Medication Score (DMS), and Total Combined Score (TCS) During the Last 8 Weeks of Treatment with ODACTRA in Subjects 18 Years of Age and Older (Study 2, European Field Efficacy Study) (NCT01454544)
| Endpoint* | ODACTRA | Placebo | Treatment Difference (ODACTRA - Placebo) | Difference Relative to Placebo§ |
| n† | Score‡ | n† | Score‡ | | Estimate | (95% CI) |
| Primary Endpoint |
| TCRS¶ | 318 | 5.71 | 338 | 6.81 | -1.09 | -16.1% | (-25.8%, -5.7%) |
| Secondary Endpoints |
| Rhinitis DSS¶ | 318 | 2.84 | 338 | 3.31 | -0.47 | -14.1% | (-23.8%, -3.9%) |
| Rhinitis DMS¶ | 318 | 2.32 | 338 | 2.86 | -0.54 | -18.9% | (-34.7%, -1.3%) |
| TCS# | 241 | 7.91 | 257 | 9.12 | -1.21 | -13.2% | (-23.7%, -1.5%) |
TCRS=Total Combined Rhinitis Score (Rhinitis DSS + Rhinitis DMS); TCS=Total Combined Score (Rhinoconjunctivitis DSS + Rhinoconjunctivitis DMS); CI=Confidence Interval
*Parametric analysis using analysis of covariance model for all endpoints.
†Number of subjects in analyses.
‡The estimated group least squares means are reported. Treatment difference and that relative to placebo is based on estimated group least squares means.
§Difference relative to placebo computed as: (ODACTRA – placebo)/placebo x 100.
¶Analysis based on FAS-MI: full analysis set with multiple imputations. The analysis treats subjects who discontinued the study before the efficacy assessment period as placebo subjects. For the primary analysis (FAS-MI) only the absolute difference was pre-specified. Additional analyses describing the corresponding pre-specified relative differences to placebo for the full analysis set (FAS): TCRS: -18.1% (-27.6%, -7.7%); rhinitis DSS: -16.2% (-25.7%, -5.8%); and rhinitis DMS: -21.4% (-36.6%, -3.2%).
#Subjects from Serbia and Croatia were excluded from the analysis of TCS because the preferred formulations of antihistamine eyedrops were not available in these countries at the time the study was conducted. The TCS analysis is based on the full analysis set (FAS). All available data used to its full extent, i.e. subjects who provided data during the efficacy assessment period.
Study 3 (Environmental Exposure Chamber Study)
This double-blind, placebo-controlled, randomized EEC study evaluated adult subjects 18 through 58 years of age comparing ODACTRA (N=42) and placebo (N=41) administered as a sublingual tablet daily for approximately 24 weeks. Subjects had a history of symptomatic allergic rhinitis and were sensitized to D. farinae and/or D. pteronyssinus as determined by HDM specific IgE. In this study, 23% of subjects had asthma, 87% had conjunctivitis, and 84% were polysensitized to other allergens in addition to HDM, including tree, grass, weed, animal danders and molds. The subject population was 90% White, <1% African American, 8% Asian, and 43% female. The mean age of subjects was 27 years.
The primary endpoint was the difference relative to placebo in the average TNSS at Week 24. The Total Nasal Symptom Score (TNSS) represents the sum of 4 nasal symptoms (runny nose, stuffy nose, sneezing, and itchy nose). Secondary endpoints were the differences relative to placebo in the average TNSS at Weeks 8 and 16 and average Total Symptom Score (TSS) at Week 24, which represents the sum of TNSS plus 2 ocular symptoms (gritty/itchy eyes and watery eyes). Baseline TNSS following house dust mite EEC challenge prior to treatment was 7.74 out of 12 total points for ODACTRA and 7.32 out of 12 total points for placebo. The results of this study are shown in Table 4.
Table 4: Total Nasal Symptom Score (TNSS) and Total Symptom Score (TSS) During HDM-Allergen Challenge (Study 3, Environmental Exposure Chamber Study) (NCT01644617)
| Endpoint* | ODACTRA (n)† Score‡ | Placebo (n)† Score‡ | Treatment Difference (ODACTRA - Placebo) | Difference Relative to Placebo§ |
| | | | Estimate | (95% CI) |
| Primary Endpoint |
TNSS – Week 24 | (36) 3.83 | (34) 7.45 | -3.62 | -48.6% | (-60.2%, -35.3%) |
| Secondary Endpoints |
TNSS – Week 8 | (40) 5.34 | (39) 6.71 | -1.37 | -20.4% | (-33.3%, -6.8%) |
TNSS – Week 16 | (39) 4.82 | (38) 6.90 | -2.08 | -30.1% | (-42.3%, -16.8%) |
TSS – Week 24 | (36) 4.43 | (34) 9.27 | -4.84 | -52.2% | (-65.0%, -37.0%) |
TNSS=Total Nasal Symptom Score; TSS=Total Symptom Score (TNSS + total ocular symptom score); CI=Confidence Interval
*Parametric analysis using analysis of covariance for all endpoints.
†Number of subjects in analyses.
‡The estimated group least squares means are reported. Treatment difference and that relative to placebo is based on estimated group least squares means.
§Difference relative to placebo computed as: (ODACTRA – placebo)/placebo x 100.