CLINICAL PHARMACOLOGY
Mechanism Of Action
The mechanism of action of
ARESTIN as an adjunct to scaling and root planing procedures for reduction of
pocket depth in patients with adult periodontitis is unknown.
Microbiology
Minocycline, a member of the
tetracycline class of antibiotics, has a broad spectrum of activity. It is bacteriostatic
and exerts its antimicrobial activity by inhibiting protein synthesis. In vitro
susceptibility testing has shown that the organisms Porphyromonas
gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Eikenella
corrodens, and Actinobacillus actinomycetemcomitans, which
are associated with periodontal disease, are susceptible to minocycline at
concentrations of ≤ 8 mcg/mL; qualitative and quantitative changes in
plaque microorganisms have not been demonstrated in subjects with
periodontitis, using this product.
The emergence of minocycline-resistant bacteria in single-site
plaque samples was studied in subjects before and after treatment with ARESTIN
at 2 centers. There was a slight increase in the numbers of minocycline-resistant bacteria at the end of the 9-month study period;
however, the number of subjects studied was small and the clinical significance
of these findings is unknown.
The emergence of minocycline-resistant bacteria and changes in the presence of Candida
albicans and Staphylococcus aureus in the gastrointestinal tract were studied
in subjects treated with ARESTIN in one phase 3 study. No changes in the
presence of minocycline-resistant bacteria or Candida
albicans or Staphylococcus aureus were seen at the end of the 56-day study period.
Pharmacokinetics
In a pharmacokinetic study, 18
subjects (10 men and 8 women) with moderate to advanced chronic periodontitis
were treated with a mean dose of 46.2 mg (25 to 112 unit doses) of ARESTIN.
After fasting for at least 10 hours, subjects received subgingival application
of ARESTIN (1 mg per treatment site) following scaling and root planing at a
minimum of 30 sites on at least 8 teeth. Investigational drug was administered
to all eligible sites ≥ 5 mm in probing depth. Mean dose normalized saliva
AUC and Cmax were found to be approximately 125 and 1000 times higher than
those of serum parameters, respectively.
Clinical Studies
In 2 well-controlled, multicenter, investigator-blind, vehicle-controlled, parallel-design studies (3 arms), 748 subjects (study OPI-103A = 368, study OPI-103B = 380) with
generalized moderate to advanced adult periodontitis characterized by a mean
probing depth of 5.90 and 5.81 mm, respectively, were enrolled. Subjects
received 1 of 3 treatments: (1) scaling and root planing (SRP), (2) SRP +
vehicle (bioresorbable polymer, PGLA), and (3) SRP + ARESTIN. To qualify for
the study, subjects were required to have 4 teeth with periodontal pockets of 6
to 9 mm that bled on probing. However, treatment was administered to all sites
with mean probing depths of 5 mm or greater. Subjects studied were in good
general health. Subjects with poor glycemic control or active infectious
diseases were excluded from the studies. Retreatment occurred at 3 and 6 months
after initial treatment, and any new site with pocket depth ≥ 5 mm also
received treatment. Subjects treated with ARESTIN were found to have
statistically significantly reduced probing pocket depth compared with those
treated with SRP alone or SRP + vehicle at 9 months after initial treatment, as
shown in Table 1.
Table 1: Probing Pocket
Depth at Baseline and Change in Pocket Depth at 9 Months from 2 Multicenter US
Clinical Trials
Time |
Study OPI-103A
N=368 |
Study OPI-103B
N=380 |
SRP Alone
n=124 |
SRP+ Vehicle
n=123 |
SRP+ ARESTIN
n=121 |
SRP Alone
n=126 |
SRP+ Vehicle
n=126 |
SRP+ ARESTIN
n=128 |
PD (mm) at Baseline [Mean ± SE] |
5.88 ± 0.04 |
5.91 ± 0.04 |
5.88 ± 0.04 |
5.79 ± 0.03 |
5.82 ± 0.04 |
5.81 ± 0.04 |
PD (mm) Change From Baseline at 9 Months [Mean ± SE] |
-1.04 ± 0.07 |
-0.90 ± 0.54 |
-1.20*†† ± 0.07 |
-1.32 ± 0.07 |
-1.30 ± 0.07 |
-1.63**†† ± 0.07 |
SE = standard error; SRP = scaling and root planing; PD =
pocket depth.
Significantly different from SRP: *(P ≤ 0.05); **(P ≤ 0.001).
Significantly different from SRP + vehicle: †† (P ≤ 0.001). |
In these 2 studies, an average
of 29.5 (5-114), 31.7 (4-137), and 31 (5-108) sites were treated at baseline in the SRP alone, SRP +
vehicle, and SRP + ARESTIN groups, respectively. When these studies are
combined, the mean pocket depth change at 9 months was -1.18 mm, -1.10 mm, and -1.42 mm for SRP alone, SRP + vehicle, and SRP + ARESTIN,
respectively.
Table 2: Numbers
(Percentage) of Pockets Showing a Change of Pocket Depth ≥ 2 mm at 9 Months from 2 Multicenter US Clinical
Trials
|
Study OPI-103A |
Study OPI-103B |
SRP Alone |
SRP+ Vehicle |
SRP+ ARESTIN |
SRP Alone |
SRP+ Vehicle |
SRP+ ARESTIN |
Pockets ≥ 2 mm (% of total) |
1046 (31.1%) |
927 (25.7%) |
1326 (36.5%) |
1692 (42.2%) |
1710 (40.0%) |
2082 (51.0%) |
Pockets ≥ 3 mm (% of total) |
417 (12.4%) |
315 (8.7%) |
548 (15.1%) |
553 (13.8%) |
524 (12.3%) |
704 (17.3%) |
SRP + ARESTIN resulted in a
greater percentage of pockets showing a change of PD ≥ 2 mm and ≥ 3
mm compared to SRP alone at 9 months, as shown in Table 2. |
Table 3: Mean Pocket Depth Changes (SE) in Subpopulations, Studies 103A and 103B Combined
|
SRP Alone |
SRP+ Vehicle |
SRP+ ARESTIN |
Smokers |
n = 91
-0.96 (± 0.09) mm |
n = 90
-0.98 (± 0.07) mm |
n = 90
-1.24 (± 0.09) mm ** |
Nonsmokers |
n = 159
-1.31 (± 0.06) mm |
n = 159
-1.17 (± 0.07) mm |
n = 159
-1.53 (± 0.06) mm ** |
Subjects > 50 YOA |
n = 21
-1.07 (± 0.09) mm |
n = 81
-0.92 (± 0.08) mm |
n = 107
-1.42 (± 0.08) mm ** |
Subjects ≤ 50 YOA |
n = 167
-1.24 (± 0.06) mm |
n = 168
-1.19 (± 0.06) mm |
n = 142
-1.43 (± 0.07) mm * |
Subjects with CV Disease |
n = 36
-0.99 (± 0.13) mm |
n = 29
-1.06 (± 0.14) mm |
n = 36
-1.56 (± 0.14) mm** |
Subjects without CV Disease |
n = 214
-1.22 (± 0.06) mm |
n = 220
-1.11 (± 0.05) mm |
n = 213
-1.40 (± 0.06) mm** |
SRP = scaling and root planing;
YOA = years of age; CV = cardiovascular
*SRP vs SRP + ARESTIN P ≤ 0.05; **SRP vs SRP + ARESTIN P ≤ 0.001 |
In both studies, the following patient subgroups were prospectively analyzed: smokers, subjects over and under
50 years of age, and subjects with a previous history of cardiovascular
disease. The results of the combined studies are presented in Table 3.
In smokers, the mean reduction
in pocket depth at 9 months was less in all treatment groups than in
nonsmokers, but the reduction in mean pocket depth at 9 months with SRP +
ARESTIN was significantly greater than with SRP + vehicle or SRP alone.
Table 4: Mean Pocket Depth
Change in Subjects with Mean Baseline PD ≥ 5
mm, ≥ 6 mm, and ≥ 7 mm at 9 Months from 2 Multicenter US Clinical
Trials
Mean Baseline Pocket Depth |
Study OPI-103A |
Study OPI-103B |
SRP Alone |
SRP+ Vehicle |
SRP+ ARESTIN |
SRP Alone |
SRP+ Vehicle |
SRP+ ARESTIN |
≥ 5 mm(n) |
-1.04 mm (124) |
-0.90 mm (123) |
-1.20 mm* (121) |
-1.32 mm (126) |
-1.30 mm (126) |
-1.63 mm* (128) |
≥ 6 mm(n) |
-0.91 mm (34) |
-0.77 mm (46) |
-1.40 mm* (45) |
-1.33 mm (37) |
-1.46 mm (40) |
-1.69 mm* (25) |
≥ 7 mm(n) |
-1.10 mm (4) |
-0.46 mm (5) |
-1.91 mm (3) |
-1.72 mm (3) |
-1.11 mm (3) |
-2.84 mm (2) |
*Statistically significant
comparison between SRP + ARESTIN and SRP alone |
The combined data from these 2 studies also show that for pockets 5 mm to 7 mm at baseline, greater reductions
in pocket depth occurred in pockets that were deeper at baseline.