CLINICAL PHARMACOLOGY
Mechanism Of Action
The presence of bactericidal anti-capsular meningococcal
antibodies has been associated with protection from invasive meningococcal
disease.6,7 Menactra vaccine induces the production of bactericidal
antibodies specific to the capsular polysaccharides of serogroups A, C, Y and
W-135.
Non-Clinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Menactra vaccine has not been evaluated for carcinogenic
or mutagenic potential, or for impairment of fertility.
Clinical Studies
Efficacy
The Serum Bactericidal Assay (SBA) used to test sera
contained an exogenous complement source that was either human (SBA-H) or baby
rabbit (SBA-BR).8
The response to vaccination following two doses of
vaccine administered to children 9 and 12 months of age and following one dose
of vaccine administered to children 2 through 10 years of age was evaluated by
the proportion of subjects having an SBA-H antibody titer of 1:8 or greater, for
each serogroup. In individuals 11 through 55 years of age, the response to
vaccination with a single dose of vaccine was evaluated by the proportion of subjects
with a 4-fold or greater increase in bactericidal antibody to each serogroup as
measured by SBA-BR. For individuals 2 through 55 years of age, vaccine efficacy
was inferred from the demonstration of immunologic equivalence to a US-licensed
meningococcal polysaccharide vaccine, Menomune - A/C/Y/W-135 vaccine as
assessed by Serum Bactericidal Assay (SBA).
Immunogenicity
Children 9 through 12 Months of Age
In a randomized, US, multi-center trial, children
received Menactra vaccine at 9 months and 12 months of age. The first Menactra
dose was administered alone, followed by a second Menactra vaccine dose given
alone (N=404), or with MMRV vaccine (N=302), or with PCV7 (N=422). For all
participants, sera were obtained approximately 30 days after last vaccination.
There were no substantive differences in demographic characteristics between
the vaccine groups. The median age range for administration of the first dose
of Menactra was 278-279 days of age.
Table 5: Bactericidal Antibody Responsesa 30 Days
Following a Second Dose of Menactra Vaccine Administered Alone or Concomitantly
Administered with MMRV or PCV7 Vaccines at 12 Months of Age
|
|
Vaccinations administered at 12 months of age following a dose of Menactra at 9 months of age |
|
|
Menactra vaccine |
Menactra + MMRV vaccines |
Menactra + PCV7 vaccines |
|
|
(N=272-277)b |
(N=177-180)b |
(N=264-267)b |
Serogroup |
|
|
(95% CI)c |
|
(95% CI)c |
|
(95% CI)c |
A |
% ≥ 1:8d GMT |
95.6 54.9 |
(92.4; 97.7) (46.8; 64.5) |
92.7 52.0 |
(87.8; 96.0) (41.8; 64.7) |
90.5 41.0 |
(86.3; 93.8) (34.6; 48.5) |
C |
% ≥ 1:8d GMT |
100.0 141.8 |
(98.7; 100.0) (123.5; 162.9) |
98.9 161.9 |
(96.0; 99.9) (136.3; 192.3) |
97.8 109.5 |
(95.2; 99.2) (94.1; 127.5) |
Y |
% ≥ 1:8d GMT |
96.4 52.4 |
(93.4; 98.2) (45.4; 60.6) |
96.6 60.2 |
(92.8; 98.8) (50.4; 71.7) |
95.1 39.9 |
(91.8; 97.4) (34.4; 46.2) |
W-135 |
% ≥ 1:8d GMT |
86.4 24.3 |
(81.8; 90.3) (20.8; 28.3) |
88.2 27.9 |
(82.5; 92.5) (22.7; 34.3) |
81.2 17.9 |
(76.0; 85.7) (15.2; 21.0) |
a Serum Bactericidal Assay with an exogenous
human complement (SBA-H) source.
b N=Number of participants with at least one valid serology result
from a blood sample obtained between Days 30 to44 post vaccination.
c 95% CIs for the proportions are calculated based on the
Clopper-Pearson Exact method and normal approximation for that of the GMTs.
d The proportion of participants achieving at
least an SBA-H titer of 1:8 thirty days after the second dose of Menactra. |
Administration of Menactra to children at 12 months and
15 months of age was evaluated in a US study. Prior to the first dose, 33.3%
[n=16/48] of participants had an hSBA titer ≥ 1:8 to Serogroup A, and 0-2%
[n=0-1 of 50-51] to Serogroups C, Y and W-135. After the second dose, percentages
of participants with an hSBA titer ≥ 1:8 were: 85.2%, Serogroup A
[n=46/54]; 100.0%, Serogroup C [n=54/54]; 96.3%, Serogroup Y [n=52/54]; 96.2%,
Serogroup W-135 [n=50/52].
Individuals 2 through 55 Years of Age
Immunogenicity was evaluated in three comparative,
randomized, US, multi-center, active controlled clinical trials that enrolled
children (2 through 10 years of age), adolescents (11 through 18 years of age),
and adults (18 through 55 years of age). Participants received a single dose of
Menactra vaccine (N=2526) or Menomune - A/C/Y/W-135 vaccine (N=2317). For all
age groups studied, sera were obtained before and approximately 28 days after
vaccination. [Blinding procedures for safety assessments are described in Adverse
Reactions (6).]
In each of the trials, there were no substantive
differences in demographic characteristics between the vaccine groups, between
immunogenicity subsets or the overall study population. In the study of
children 2 through 10 years of age, the median age of participants was 3 years;
95% completed the study. In the adolescent trial, the median age for both
groups was 14 years; 99% completed the study. In the adult trial, the median
age for both groups was 24 years; 94% completed the study.
Immunogenicity in Children 2 through 10 Years of Age
Of 1408 enrolled children 2 through 10 years of age,
immune responses evaluated in a subset of Menactra vaccine participants (2
through 3 years of age, n=52; 4-10 years of age, n=84) and Menomune -
A/C/Y/W-135 vaccine participants (2 through 3 years of age, n=53; 4-10 years of
age, n=84) were comparable for all four serogroups (Table 6).
Table 6: Comparison of Bactericidal Antibody Responsesa
to Menactra Vaccine and Menomune - A/C/Y/W-135 Vaccine 28 Days after
Vaccination for a Subset of Participants 2 through 3 Years of Age and 4 through
10 Years of Age
|
|
Ages 2 through 3 Years |
Ages 4 through 10 Years |
Menactra vaccine |
Menomune -A/C/Y/W-135 vaccine |
Menactra vaccine |
Menomune -A/C/Y/W-135 vaccine |
|
|
Nb=48-52 |
Nb=50-53 |
Nb=84 |
Nb=84 |
Serogroup |
|
|
(95% CI)c |
|
(95% CI)c |
|
(95% CI)c |
|
(95% CI)c |
A |
% ≥ 1:8d |
73 |
(59,84) |
64 |
(50,77) |
81 |
(71,89) |
55 |
(44,66) |
GMT |
10 |
(8,13) |
10 |
(7,12) |
19 |
(14,26) |
7 |
(6,9) |
C |
% ≥ 1:8d |
63 |
(48,76) |
38 |
(25,53) |
79 |
(68,87) |
48 |
(37,59) |
GMT |
27 |
(14,52) |
11 |
(5,21) |
28 |
(19,41) |
12 |
(7,18) |
Y |
% ≥ 1:8d |
88 |
(75,95) |
73 |
(59,84) |
99 |
(94,100) |
92 |
(84,97) |
GMT |
51 |
(31,84) |
18 |
(11,27) |
99 |
(75,132) |
46 |
(33,66) |
W-135 |
% ≥ 1:8d |
63 |
(47,76) |
33 |
(20,47) |
85 |
(75,92) |
79 |
(68,87) |
GMT |
15 |
(9,25) |
5 |
(3,6) |
24 |
(18,33) |
20 |
(14,27) |
a Serum Bactericidal Assay with an exogenous
human complement (SBA-H) source.
b N=Number of subset participants with at least one valid serology
result at Day 0 and Day 28.
c The 95% CI for the Geometric Mean Titer (GMT) was calculated based
on an approximation to the normal distribution.
d The proportion of participants achieving at least an SBA-H titer
of 1:8 was assessed using a 10% non-inferiority margin and a one-sided Type 1
error rate of 0.025. |
In the subset of participants 2 through 3 years of age
with undetectable pre-vaccination titers (ie, < 1:4 at Day 0), seroconversion
rates (defined as ≥ 1:8 at Day 28) were similar between the Menactra
vaccine and Menomune - A/C/Y/W-135 vaccine recipients. Menactra vaccine participants
achieved seroconversion rates of: 57%, Serogroup A (n=12/21); 62%, Serogroup C (n=29/47);
84%, Serogroup Y (n=26/31); 53%, Serogroup W-135 (n=20/38). The seroconversion rates
for Menomune - A/C/Y/W-135 vaccine recipients were: 55%, Serogroup A (n=16/29);
30%, Serogroup C (n=13/43); 57%, Serogroup Y (n=17/30); 26%, Serogroup W-135
(n=11/43).
In the subset of participants 4 through 10 years of age
with undetectable pre-vaccination titers (ie, < 1:4 at Day 0), seroconversion
rates (defined as ≥ 1:8 at Day 28) were similar between the Menactra
vaccine and Menomune - A/C/Y/W-135 vaccine recipients. Menactra vaccine participants
achieved seroconversion rates of: 69%, Serogroup A (n=11/16); 81%, Serogroup C (n=50/62);
98%, Serogroup Y (n=45/46); 69%, Serogroup W-135 (n=27/39). The seroconversion rates
for Menomune - A/C/Y/W-135 vaccine recipients were: 48%, Serogroup A (n=10/21);
38%, Serogroup C (n=19/50); 84%, Serogroup Y (n=38/45); 68%, Serogroup W-135
(n=26/38).
Immunogenicity in Adolescents 11 through 18 Years of Age
Results from the comparative clinical trial conducted in
881 adolescents aged 11 through 18 years showed that the immune responses to
Menactra vaccine and Menomune - A/C/Y/W-135 vaccine were similar for all four
serogroups (Table 7).
In participants with undetectable pre-vaccination titers
(ie, less than 1:8 at Day 0), seroconversion rates (defined as a ≥ 4-fold
rise in Day 28 SBA-BR titers) were similar between the Menactra vaccine and
Menomune - A/C/Y/W-135 vaccine recipients. Menactra vaccine participants achieved
seroconversion rates of: 100%, Serogroup A (n=81/81); 99%, Serogroup C
(n=153/155); 98%, Serogroup Y (n=60/61); 99%, Serogroup W-135 (n=161/164). The
seroconversion rates for Menomune - A/C/Y/W-135 vaccine recipients were: 100%,
Serogroup A (n=93/93); 99%, Serogroup C (n=151/152); 100%, Serogroup Y
(n=47/47); 99%, Serogroup W-135 (n=138/139).
Immunogenicity in Adults 18 through 55 Years of Age
Results from the comparative clinical trial conducted in
2554 adults aged 18 through 55 years showed that the immune responses to
Menactra vaccine and Menomune - A/C/Y/W-135 vaccine were similar for all four
serogroups (Table 7).
Table 7: Comparison of Bactericidal Antibody Responsesa
to Menactra Vaccine and Menomune - A/C/Y/W-135 Vaccine 28 Days after
Vaccination for Participants 11 through 18 Years of Age and 18 through 55 Years
of Age
|
|
Ages 11 through 18 Years |
Ages 18 through 55 Years |
|
|
Menactra vaccine |
Menomune -A/C/Y/W-135 vaccine |
Menactra vaccine |
Menomune -A/C/Y/W-135 vaccine |
|
|
Nb=423 |
Nb=423 |
Nb=1280 |
Nb=1098 |
Serogroup |
|
|
(95% CI)c |
|
(95% CI)c |
|
(95% CI)c |
|
(95% CI)c |
A |
% ≥ 4-fold rised GMT |
92.7 5483 |
(89.8, 95.0) (4920, 6111) |
92.4 3246 |
(89.5, 94.8) (2910, 3620) |
80.5 3897 |
(78.2, 82.6) (3647, 4164) |
84.6 4114 |
(82.3, 86.7) (3832, 4417) |
C |
% ≥ 4-fold rised GMT |
91.7 1924 |
(88.7, 94.2) (1662, 2228) |
88.7 1639 |
(85.2, 91.5) (1406, 1911) |
88.5 3231 |
(86.6, 90.2) (2955, 3533) |
89.7 3469 |
(87.8, 91.4) (3148, 3823) |
Y |
% ≥ 4-fold rised GMT |
81.8 1322 |
(77.8, 85.4) (1162, 1505) |
80.1 1228 |
(76.0, 83.8) (1088, 1386) |
73.5 1750 |
(71.0, 75.9) (1597, 1918) |
79.4 2449 |
(76.9, 81.8) (2237, 2680) |
W-135 |
% ≥ 4-fold rised GMT |
96.7 1407 |
(94.5, 98.2) (1232, 1607) |
95.3 1545 |
(92.8, 97.1) (1384, 1725) |
89.4 1271 |
(87.6, 91.0) (1172, 1378) |
94.4 1871 |
(92.8, 95.6) (1723, 2032) |
a Serum Bactericidal Assay with baby rabbit
complement (SBA-BR).
b N=Number of subset participants with at least one valid serology
result at Day 0 and Day 28.
c The 95% CI for the Geometric Mean Titer (GMT) was calculated based
on an approximation to the normal distribution.
d Menactra vaccine was non-inferior to Menomune - A/C/Y/W-135
vaccine. Non-inferiority was assessed by the proportion of participants with a
4-fold or greater rise in SBA-BR titer for N meningitidis serogroups A,
C, Y and W-135 using a 10% non-inferiority margin and a one-sided Type I error
rate of 0.05. |
In participants with undetectable pre-vaccination titers
(ie, less than 1:8 at Day 0), seroconversion rates (defined as a ≥ 4-fold
rise in Day 28 SBA-BR titers) were similar between the Menactra vaccine and
Menomune - A/C/Y/W-135 vaccine recipients. Menactra vaccine participants achieved
seroconversion rates of: 100%, Serogroup A (n=156/156); 99%, Serogroup C (n=343/345);
91%, Serogroup Y (n=253/279); 97%, Serogroup W-135 (n=360/373). The seroconversion
rates for Menomune - A/C/Y/W-135 vaccine recipients were: 99%, Serogroup A (n=143/144);
98%, Serogroup C (n=297/304); 97%, Serogroup Y (n=221/228); 99%, Serogroup W-135
(n=325/328).
Concomitant Vaccine Administration
MMR V (or MMR + V) or PCV7
In a US, active-controlled trial, 1179 children received
Menactra vaccine at 9 months and 12 months of age. At 12 months of age these
children received Menactra concomitantly with MMRV (N=616), or MMR + V (N=48),
or PCV7 (N=250). Another group of 12-month old children received MMRV + PCV7
(N=485). Sera were obtained approximately 30 days after the last vaccinations.
Measles, mumps, rubella and varicella antibody responses among children who received
Menactra vaccine and MMRV (or MMR and V) were comparable to corresponding antibody
responses among children who received MMRV and PCV7.
When Menactra was given concomitantly with PCV7, the
non-inferiority criteria for comparisons of pneumococcal IgG GMCs (upper limit
of the two-sided 95% CI of the GMC ratio ≤ 2) were not met for 3 of 7
serotypes (4, 6B, 18C). In a subset of subjects with available sera,
pneumococcal opsonophagocytic assay GMT data were consistent with IgG GMC data.
Td
In a double-blind, randomized, controlled trial, 1021
participants aged 11 through 17 years received Td and Menactra vaccines
concomitantly (N=509), or Td followed one month later by Menactra vaccine
(N=512). Sera were obtained approximately 28 days after each respective vaccination.
The proportion of participants with a 4-fold or greater increase in SBA-BR
titer to meningococcal Serogroups C, Y and W-135 was higher when Menactra
vaccine was given concomitantly with Td (86-96%) than when Menactra vaccine was
given one month following Td (65-91%). Anti-tetanus and anti-diphtheria
antibody responses were similar in both study groups.
Typhim Vi
In a double-blind, randomized, controlled trial, 945
participants aged 18 through 55 years received Typhim Vi and Menactra vaccines
concomitantly (N=469), or Typhim Vi vaccine followed one month later by
Menactra vaccine (N=476). Sera were obtained approximately 28 days after each
respective vaccination. The antibody responses to Menactra vaccine and to Typhim
Vi vaccine components were similar in both study groups.
REFERENCES
6 Makela PH, et al. Evolution of conjugate vaccines.
Expert Rev Vaccines 2002;1(3):399- 410.
7 Goldschneider I, et al. Human immunity to the
meningococcus. I. The Role of Humoral Antibodies. J Exp Med 1969;129:1307-1326.
8 Maslanka SE, et al. Standardization and a
Multilaboratory Comparison of Neisseria meningitidis Serogroup A and C Serum
Bactericidal Assays. Clin and Diag Lab Immunol 1997;156-167.