CLINICAL PHARMACOLOGY
Mechanism Of Action
The risk of developing herpes zoster (HZ) increases with age and appears to be related to a decline in VZV-specific immunity. SHINGRIX was shown to boost VZV-specific immune response, which is thought to be the mechanism by which it protects against zoster disease [see Clinical Studies].
Clinical Studies
Efficacy In Subjects 50 Years And Older
Study 1 was a randomized, placebo-controlled, observer-blind clinical study conducted in 18 countries. Randomization was stratified (8:5:3:1) by age: 50 to 59 years, 60 to 69 years, 70 to 79 years, and ≥80 years. The study excluded, among others, subjects who were immunocompromised, had a history of previous HZ, were vaccinated against varicella or HZ, and patients whose survival was not expected to be at least 4 years or with conditions that might interfere with study evaluations. Subjects were followed for the development of HZ and postherpetic neuralgia (PHN) for a median of 3.1 years (range: 0 to 3.7 years). Suspected HZ cases were followed prospectively for the development of PHN, an HZ-related complication defined as HZ-associated pain (rated as 3 or greater on a 0- to 10-point scale by the study subject) occurring or persisting at least 90 days following the onset of rash in confirmed cases of HZ.
The primary efficacy analysis population (referred to as the modified Total Vaccinated Cohort [mTVC]) included 14,759 subjects aged 50 years and older who received 2 doses (0 and 2 months) of either SHINGRIX (n = 7,344) or placebo (n = 7,415) and did not develop a confirmed case of HZ within 1 month after the second dose. In the mTVC population, 61.2% were female; 72.3% were white, 18.9% were Asian, 1.7% were black, and 7.0% were of other racial/ethnic groups. The mean age of subjects was 62.3 years.
Confirmed HZ cases were determined by either Polymerase Chain Reaction (PCR) (89.4%) or by a Clinical Evaluation Committee (10.6%).
Efficacy Against Herpes Zoster
Compared with placebo, SHINGRIX significantly reduced the risk of developing HZ by 97.2% (95% CI: 93.7, 99.0) in subjects 50 years and older (Table 2).
Table 2. Efficacy of SHINGRIX on Incidence of Herpes Zoster Compared with Placebo in Study 1a (mTVCb)
Age Group
(Years) |
SHINGRIX |
Placebo |
% Efficacy (95% CI) |
N |
n |
Incidence Rate of HZ per 1,000 Person-Years |
N |
n |
Incidence Rate of HZ per 1,000 Person-Years |
Overall (≥50)c |
7,344 |
6 |
0.3 |
7,415 |
210 |
9.1 |
97.2
(93.7, 99.0) |
50 - 59 |
3,492 |
3 |
0.3 |
3,525 |
87 |
7.8 |
96.6
(89.6, 99.3) |
60 - 69 |
2,141 |
2 |
0.3 |
2,166 |
75 |
10.8 |
97.4
(90.1, 99.7) |
≥70 |
1,711 |
1 |
0.2 |
1,724 |
48 |
9.4 |
97.9
(87.9, 100.0) |
N = Number of subjects included in each group; n = Number of subjects having at least 1 confirmed HZ episode; HZ = Herpes zoster; CI = Confidence Interval.
a Study 1: NCT01165177.
b mTVC = Modified Total Vaccinated Cohort defined as subjects who received 2 doses (0 and 2 months) of either SHINGRIX or placebo and did not develop a confirmed case of HZ within 1 month after the second dose.
c Primary study endpoint was based on confirmed HZ cases in subjects aged 50 years and older. |
In a descriptive analysis, vaccine efficacy against HZ in subjects aged 50 years and older was 93.1% (95% CI: 81.3, 98.2) in the fourth year post-vaccination.
Occurrence Of PHN
Among all subjects aged 50 years or older in the mTVC, no cases of PHN were reported in the vaccine group compared with 18 cases reported in the placebo group.
Efficacy In Subjects 70 Years And Older
Study 2 was a randomized, placebo-controlled, observer-blind clinical study conducted in 18 countries. Randomization was stratified (3:1) by age: 70 to 79 years and ≥80 years. With the exception of age, the study exclusion criteria were the same as for Study 1. Subjects were followed for the development of HZ and PHN for a median of 3.9 years (range: 0 to 4.5 years). Suspected HZ cases were followed prospectively for the development of PHN as for Study 1.
The primary efficacy analysis population (mTVC) included 13,163 subjects aged 70 years and older who received 2 doses (0 and 2 months) of either SHINGRIX (n = 6,541) or placebo (n = 6,622) and did not develop a confirmed case of HZ within 1 month after the second dose. In the mTVC population, 54.7% were female; 77.6% were white, 17.1% were Asian, 1.0% were black, and 4.2% were of other racial/ethnic groups. The mean age of subjects was 75.5 years.
Confirmed HZ cases were determined by either PCR (92.3%) or by a Clinical Evaluation
Committee (7.7%).
Efficacy Against Herpes Zoster
Vaccine efficacy results against HZ in subjects 70 years and older are shown in Table 3.
Table 3. Efficacy of SHINGRIX on Incidence of Herpes Zoster Compared with Placebo in Study 2a (mTVCb)
Age Group
(Years) |
SHINGRIX |
Placebo |
% Efficacy (95% CI) |
N |
N |
Incidence Rate of HZ per 1,000 Person-Years |
N |
N |
Incidence Rate of HZ per 1,000 Person-Years |
Overall (≥70)c |
6,541 |
23 |
0.9 |
6,622 |
223 |
9.2 |
89.8
(84.3, 93.7) |
70 - 79 |
5,114 |
17 |
0.9 |
5,189 |
169 |
8.8 |
90.0
(83.5, 94.3) |
≥80 |
1,427 |
6 |
1.2 |
1,433 |
54 |
11.0 |
89.1
(74.7, 96.2) |
N = Number of subjects included in each group; n = Number of subjects having at least 1 confirmed HZ episode; HZ = Herpes zoster; CI = Confidence Interval.
a Study 2: NCT01165229.
b mTVC = Modified Total Vaccinated Cohort defined as subjects who received 2 doses (0 and 2 months) of either SHINGRIX or placebo and did not develop a confirmed case of HZ within 1 month after the second dose.
c Primary study endpoint was based on confirmed HZ cases in subjects aged 70 years and older. |
In a descriptive analysis, vaccine efficacy against HZ in subjects 70 years and older was 85.1% (95% CI: 64.5, 94.8) in the fourth year after vaccination.
Efficacy Against PHN
Among all subjects aged 70 years or older in the mTVC, 4 cases of PHN were reported in the vaccine group compared with 28 cases reported in the placebo group. Vaccine efficacy against PHN was 85.5% (95% CI: [58.5; 96.3]). The benefit of SHINGRIX in the prevention of PHN can be attributed to the effect of the vaccine on the prevention of HZ.
Reduction Of Use Of Pain Medication
Among subjects with confirmed HZ, the use of HZ-associated pain medications was reported for 10 of 23 subjects (43.5%) who received SHINGRIX and for 160 of 223 subjects (71.7%) who received placebo.
Pooled Efficacy Analyses Across Studies 1 And 2
The efficacy of SHINGRIX to prevent HZ and PHN in subjects 70 years and older was evaluated by combining the results from Studies 1 and 2 through a pre-specified pooled analysis in the mTVC. A total of 8,250 and 8,346 subjects who received SHINGRIX and placebo, respectively, were included in the pooled mTVC analysis.
Efficacy Against Herpes Zoster
Compared with placebo, SHINGRIX significantly reduced the risk of developing HZ by 91.3% (95% CI: 86.9, 94.5) in subjects 70 years and older (Table 4).
Table 4. Efficacy of SHINGRIX on Incidence of Herpes Zoster Compared with Placebo in Studies 1 and 2 (Pooled Dataa) (mTVCb)
Age Group
(Years) |
SHINGRIX |
Placebo |
% Efficacy (95% CI) |
N |
n |
Incidence Rate of HZ per 1,000 Person-Years |
N |
n |
Incidence Rate of HZ per 1,000 Person-Years |
Overall (≥70)c |
8,250 |
25 |
0.8 |
8,346 |
284 |
9.3 |
91.3
(86.9, 94.5) |
70 - 79 |
6,468 |
19 |
0.8 |
6,554 |
216 |
8.9 |
91.3
(86.0, 94.9) |
≥80 |
1,782 |
6 |
1.0 |
1,792 |
68 |
11.1 |
91.4
(80.2, 96.9) |
N = Number of subjects included in each group; n = Number of subjects having at least 1 confirmed HZ episode; HZ = Herpes zoster; CI = Confidence Interval.
a Pooled data from Study 1: NCT01165177 (subjects ≥50 years) and Study 2: NCT01165229 (subjects ≥70 years).
b mTVC = Modified Total Vaccinated Cohort defined as subjects who received 2 doses (0 and 2 months) of either SHINGRIX or placebo and did not develop a confirmed case of HZ within 1 month after the second dose.
c Primary endpoint of pooled analysis was based on confirmed HZ cases in subjects 70 years and older. |
Efficacy Against PHN
Table 5 compares the overall rates of PHN in the vaccine and placebo groups across both studies.
Table 5. Efficacy of SHINGRIX on Overall Incidence of Postherpetic Neuralgia Compared with Placebo in Studies 1 and 2 (Pooled Dataa) (mTVCb)
Age Group
(Years) |
SHINGRIX |
Placebo |
% Efficacy (95% CI) |
N |
n |
Incidence Rate of PHNc per 1,000 Person-Years |
N |
n |
Incidence Rate of PHN per 1,000 Person-Years |
Overall (≥70) |
8,250 |
4 |
0.1 |
8,346 |
36 |
1.2 |
88.8
(68.7, 97.1) |
70 - 79 |
6,468 |
2 |
0.1 |
6,554 |
29 |
1.2 |
93.0
(72.5, 99.2) |
≥80 |
1,782 |
2 |
0.3 |
1,792 |
7 |
1.1 |
71.2
(-51.5, 97.1) |
N = Number of subjects included in each group; n = Number of subjects having at least 1 PHN; CI = Confidence Interval.
a Pooled data from Study 1: NCT01165177 (subjects ≥50 years) and Study 2: NCT01165229 (subjects ≥70 years).
b mTVC = Modified Total Vaccinated Cohort defined as subjects who received 2 doses (0 and 2 months) of either SHINGRIX or placebo and did not develop a confirmed case of HZ within 1 month after the second dose.
c PHN = Postherpetic neuralgia defined as HZ-associated pain rated as 3 or greater (on a 0- to 10-point scale) occurring or persisting at least 90 days following the onset of rash using Zoster Brief Pain Inventory questionnaire. |
The benefit of SHINGRIX in the prevention of PHN can be attributed to the effect of the vaccine on the prevention of HZ. The efficacy of SHINGRIX in the prevention of PHN in subjects with confirmed HZ could not be demonstrated.
Immunological Evaluation To Support Dosing Schedule
A measure of the immune response that confers protection against HZ is unknown. Anti-gE antibody levels were measured by anti-gE enzyme-linked immunosorbent assay (gE ELISA) and were used to support the dosing schedule.
In an open-label clinical study, 238 subjects 50 years and older received SHINGRIX on either a 0- and 2-month or 0- and 6-month schedule. Non-inferiority of the 0- and 6-month schedule compared with the 0- and 2-month schedule based on anti-gE ELISA GMCs 1 month after the second dose was demonstrated.
Concomitant Administration With Influenza Vaccine
In an open-label clinical study, subjects 50 years and older received 1 dose each of SHINGRIX and FLUARIX QUADRIVALENT (QIV) at Month 0 and 1 dose of SHINGRIX at Month 2 (n =
14413), or 1 dose of QIV at Month 0 and 1 dose of SHINGRIX at Months 2 and 4 (n = 415). There was no evidence for interference in the immune response to any of the antigens contained in SHINGRIX or the coadministered vaccine.
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