The safety and efficacy of RUCONEST for treatment of acute angioedema attacks in patients with HAE was established in Study 1, a double-blind, randomized, placebo-controlled trial (RCT) which included an open-label extension (OLE) phase; and supported by the results of 2 additional RCTs and 2 additional OLE studies.
Randomized, Controlled Trials
The safety and efficacy of RUCONEST in the treatment of acute attacks in patients with hereditary angioedema were demonstrated in a placebo-controlled, double-blind, randomized study (Study 1). Supportive evidence of effectiveness is provided by two double-blind, randomized, placebo-controlled studies (Studies 2 and 3). Evidence for the efficacy of repeat treatment of HAE attacks is provided from the open-label extensions (OLE) of each of the three randomized studies.
Study 1 was a randomized, double-blind, placebo-controlled trial that included an open-label extension (OLE) phase to assess the efficacy and safety of RUCONEST 50 U/kg in the treatment of acute attacks in patients with HAE. Seventy-five (75) adults and adolescent patients were randomized (3:2) to receive RUCONEST 50 U/kg (N = 44) or placebo (N = 31). Patients ranged in age from 17 to 69 years of age; 63% were female and 37% were male; 96% were Caucasian.
The primary efficacy endpoint was the time to beginning of relief of symptoms, assessed using patient-reported responses to two questions from a Treatment Effect Questionnaire (TEQ). The TEQ required patients to assess the severity of their attack symptoms at each affected anatomic location, using a seven-point scale (“much worse” to “much better” [TEQ Question 1]), and whether their symptoms had begun to decrease notably since receiving the study medication (“yes” or “no” [TEQ Question 2]). To achieve the primary endpoint, a patient had to have a positive response to both questions along with persistence of improvement at the next assessment time (i.e., the same or better response).
Rescue treatment with RUCONEST was available for patients who did not experience the beginning of relief at 4 hours after study drug administration, or earlier to patients who experienced life-threatening oropharyngeal-laryngeal angioedema symptoms. If a patient received a medication which could have impacted the efficacy evaluation or open-label RUCONEST as rescue medication, prior to achieving beginning of relief of symptoms, the time to beginning of relief of symptoms was censored at the last assessed time prior to medication use.
In the RCT phase, the median time to beginning of relief of symptoms was statistically significantly shorter in patients treated with RUCONEST 50 U/kg compared with patients treated with placebo as assessed by the TEQ; (
Table 6, Figure 1).
Table 6. Time to Beginning of Relief of Symptoms based on questionnaire based on TEQ (Study 1, RCT Phase)| Time to Beginning of Relief of Symptoms, minutes | RUCONEST 50 U/kg N=44 | Placebo N=31 |
|---|
| Values that are not estimable are displayed as ‘- ’. |
Median | 90 | 152 |
95% CI | (61, 150) | (93, -) |
Log-rank p-value | 0.031 |
Figure 1. Kaplan-Meier Plot of Time to Beginning of Relief of Symptoms (Study 1, RCT Phase)
Among several planned subgroup analyses, descriptive statistics showed that in US patients a median time to beginning of relief of symptoms with persistence at the primary attack location (based on TEQ) was 98 minutes [95% CI:(45, 240); n=22] for those receiving RUCONEST and 90 minutes [95% CI: (50, -); n=16] for those receiving placebo. The hazard ratio for time to the beginning of relief of symptoms in this subpopulation was 1.20 [95% CI: (0.48, 3.01)] for patients receiving RUCONEST as compared with patients receiving placebo. Non-US patients receiving RUCONEST had a median time to beginning of relief of 90 minutes [95% CI: (63, 120); n=22] and non-US patients receiving placebo had a median time to beginning of relief of 334 minutes [95% CI: (150, -); n=15]. The hazard ratio for the non-US subgroup was 4.82 [95% CI: (1.58, 14.72)] for patients receiving RUCONEST compared to placebo.
Examination of gender subgroups suggested a larger treatment effect in men than women. For women receiving RUCONEST, the median time to beginning of relief was 113 minutes [95% CI: (63, 151); n=28], and for women receiving placebo, the median time to beginning of relief was 105 minutes [95% CI: (60, 334); n=19]. The hazard ratio for women receiving RUCONEST versus placebo was 1.22 [95% CI: (0.60, 2.48)]. For men receiving RUCONEST, the median time to beginning of relief was 75 minutes [95% CI: (45, 210); n=16], and for men receiving placebo, the median time to beginning of relief was 480 minutes [95% CI: (150, -) n=12]. The hazard ratio for men receiving RUCONEST versus placebo was 3.94 [95% CI: (1.23, 12.68)].
No plausible biological explanations for the regional or gender subgroup effects were found. One possible explanation is a larger-than-expected placebo response among US women. None of the subgroup confidence intervals were adjusted for multiplicity.
Because almost all of the patients were Caucasian and were between 18 and 65 years of age, race and age subgroup analyses were not considered meaningful.
Among patients who achieved relief within 4 hours, there were 4 (27%) patients in the placebo group who had a relapse of their symptoms within 24 hours as compared with 1 (3%) in the RUCONEST group. The proportion of patients who received RUCONEST as rescue medication was greater in patients randomized to placebo (13 of 31 patients; 42%) than in patients randomized to RUCONEST (5 of 44 patients; 11%).
The efficacy of RUCONEST 50 U/kg for different anatomical locations of HAE attacks is summarized in
Table 7.
Table 7. Proportion of patients who achieved relief within 4 hours, by attack type| *Life-threatening laryngeal attacks were excluded from the randomized-controlled phase of Study 1
|
Attack Type
* | RUCONEST 50 U/kg n/N (%) | Placebo n/N (%) |
Abdominal | 14/16 (88%) | 7/12 (58%) |
Facial | 3/6 (50%) | 0/2 (0%) |
Peripheral (extremities) | 17/20 (85%) | 7/14 (50%) |
In the OLE phase of Study 1, patients were treated with open-label RUCONEST 50 U/kg for repeated attacks of HAE. Forty-four patients who completed the RCT phase were enrolled into the OLE phase where they were treated for a total of 170 attacks. In this phase, the median time to beginning of relief of symptoms was 75 minutes [95% CI: (64, 90)], consistent with the results of the RCT phase of the study (
Table 6). Results were also comparable across attacks, suggesting that the efficacy of RUCONEST 50 U/kg was maintained over repeated attacks of HAE. In the OLE phase of Study 1, 5/170 (3%) attacks received a second dose of RUCONEST 50 U/kg.
In Study 2 (North American RCT), patients were randomized to receive a single administration of either RUCONEST 50 U/kg (N=12), RUCONEST 100 U/kg (N=13) or placebo (N=13). Patients ranged in age from 17 to 66 years of age; 74% were female and 26% were male; and 92% were Caucasian.
In Study 3 (European RCT), patients were randomized to receive a single administration of either RUCONEST 100 U/kg (N=16) or placebo (N=16). Patients ranged in age from 17 to 71 years of age: 53% were female and 47% were male; and 100% were Caucasian.
Patients scored their symptoms using a visual analog scale (VAS) ranging from 0-100 mm. A VAS decrease of
> 20 mm compared with baseline with persistence of the improvement at two consecutive time points was considered the onset of relief in Studies 2 and 3.
In both Study 2 and 3, the efficacy of RUCONEST in the treatment of acute angioedema attacks was demonstrated by significantly shorter times to beginning of relief of symptoms based on the VAS (Figure 2).
Figure 2. Mean VAS scores over time with 95% Confidence Intervals (Study 2 and 3, RCT Phase)
In open-label extension studies of Study 2 and 3, 119 patients were treated with RUCONEST for a total of 362 acute angioedema attacks. As observed in Study 1, the efficacy of RUCONEST was maintained for repeat attacks.