CLINICAL PHARMACOLOGY
Clinical Study
The use of Hyalgan®
as a treatment for pain in OA of the knee was investigated in a multicenter
clinical trial conducted in the United States.
Study Design
This study was a double-masked, placebo and
naproxen-controlled, multicenter prospective clinical trial with three
treatment arms, as summarized in Table 2. A total of 495 subjects with moderate
to severe pain was randomized (at baseline evaluation) into three treatment
groups in a ratio of 1:1:1 Hyalgan®,
placebo, or naproxen.
TABLE 2 STUDY DESIGN
Routes of Administration |
Hyalgan® |
Placebo |
Naproxen |
S.C. i.a.* p.o./b.i.d. p.o./p.r.n. (not to exceed 4 grams/day) |
Lidocaine (1%) Hyalgan® (20 mg/2 mL) Placebo for naproxen capsules Acetaminophen |
Lidocaine (1%) Phosphate-Buffered Saline (2 mL) Placebo for naproxen capsules Acetaminophen |
Lidocaine (1%) none Naproxen capsules (500 mg) Acetaminophen |
Legend: s.c. = subcutaneous; i.a. = intra-articular; p.o.
= by mouth; b.i.d. = twice a day; p.r.n. = as needed
* Synovial fluid was aspirated (when present) in the Hyalgan® and placebo groups. |
Patient Population And Demographics
The demographics of trial participants were comparable
across treatment groups with regard to age, sex, race, height, weight, history
of osteoarthritis, prior use of NSAIDs, prior physical therapy, and use of
assistive devices (refer to Table 3).
Evaluation Schedule
After meeting initial screening requirements NSAID
therapy was discontinued. After 2 weeks, all subjects returned for baseline
evaluations. The baseline evaluation included assessment of three primary
effectiveness criteria; measurement of pain during a 50-foot walk test using a
100 mm Visual Analog Scale (VAS), a categorical assessment (0 = none to 5 =
disabled) of pain, as assessed by a masked evaluator, during the 48 hours preceding
the visit, and a categorical assessment (0 = none to 5 = disabled) of pain, as
assessed by the subject, during the 48 hours preceding the visit.
All subjects who completed the NSAID washout period and
met all entry requirements received their first injection after randomization.
All subjects received subcutaneous lidocaine injections.
Intra-articular injections (Hyalgan®, placebo) were administered weekly for a
total of 5 injections (Weeks 0-^4). The naproxen group received 500 mg of
naproxen to be taken b.i.d. for 26 weeks.
Subsequent visits and evaluations took place at Weeks 5,
9, 1 2 ,1 6 , 21, and 26. Safety and effectiveness criteria were assessed and
recorded at these time periods.
Clinical Results
For this trial, overall success for effectiveness was
defined as meeting all four of the success criteria listed in Table 4 using
scores from week 26. The criteria were met (refer to Tables 4 through 8).
Additional Analyses
- An analysis of study completers was performed as
follows: Success was defined as 1) achieving a 20 mm decrease in the VAS
for the 50-foot walk test by Week 5, and 2) maintaining this improvement
through Week 26. In this analysis greater proportions of Hyalgan®-treated subjects (59/105, 56%) than either
placebo (47/115, 41%) or naproxen-treated subjects (51/113, 45%) were successful
under this definition. The Hyalgan®-placebo
comparison was statistically significant (p=0.031, Fisher's Exact Test). Since
patients were not followed beyond Week 26, it is unknown how long pain relief
continued. There are reports in the literature of some patients experiencing
benefit beyond 26 weeks.
- Categorical Assessment of Pain - Subjects: A
longitudinal analysis of categorical assessment of pain by the subject, which
analyzed the percentage of subjects who attained success revealed that a
significantly higher percentage of Hyalgan*-treated subjects as compared to the
placebo-treated subjects (55/105, 52% vs 43/115, 37%, p = 0.030, Fisher's Exact
Test) achieved success (an improvement of greater than or equal to one point on
the five-point scale) and maintained this success from Week 5 until Week 26.
Supplementary Clinical Information
Three randomized, controlled clinical investigations were
performed that provide information about a three-injection treatment course of Hyalgan®. In all of the studies the patients were
followed for 60 days.
Two studies provided a comparison to placebo. One of the
placebo-controlled studies evaluated two treatment doses of Hyalgan®, 20 mg/2 ml and 40 mg/2 ml. The 20 mg/2 ml
treatment arm included 19 knees, the 40 mg/2 ml included 20 knees, and the
placebo arm included 18 knees.
The other placebo study included 20 knees in the
treatment group and 18 knees in the placebo-treatment group. The third study
provided a comparison between patients treated with three weekly injections of
Hyalgan® followed by 2 weekly
treatments with arthrocentesis with patients treated with arthrocentesis for
five weeks, and arthrocentesis and placebo injections for five weeks.
Additional arms of this study assessed additional treatment regimens.
Statistical evaluation of the data was performed at day 60. In this study, only
patients considered to be success were followed beyond day 60. These patients
were followed for 180 days, however, due to the number of dropouts, statistical
evaluation was not performed on data gathered at time points beyond day 60. The
results of these investigations reported that the three-injection Hyalgan® treated patients experienced pain relief
beginning at day 21 and continuing throughout the remaining 60-day observation
period.
Safety
In order for the product to be considered safe, the
incidence of severe swelling and pain consequent to intra-articular injection
should be less than 5%. This criterion was met as indicated in Table 1. See the
Adverse Events Section.
TABLE 1: Incidence1 of Adverse Events Occurring in
More than 5% of All Subjects
Adverse Event |
Hyalgan®
N = 164 |
Placebo
N = 168 |
Gastrointestinal Complaints2 |
48 (29%) |
59 (36%) |
Injection site pain3 |
38 (23%)4 |
22(13%) |
Headache |
30(18%) |
29(17%) |
Local skin5 |
23 (14%) |
17(10%) |
Local joint pain and swelling6 |
21 (13%) |
22(13%) |
Pruritus (local) |
12(7%) |
7(4%) |
Notes: 1Numberand %of subjects
2vere in 4 Hyalgan' -treated subjects and 4 placebo-treated subjects
3Severe in 5 Hyalgan'-treated subjects and 2 placebo-treated subjects
4Statistically significant (p=0.02)
5includes ecchymosis and rash
6Severe in 2 Hyalgan”-treated subjects (1.2%) and 1 placebo-treated
subject |
TABLE 3: Demographic Characteristics of all
randomized subjects
DEMOGRAPHIC VARIABLE |
TREATMENT |
TOTAL
N =495 |
Hyalgan®
N = 164 |
Placebo
N = 168 |
Naproxen
N = 163 |
AGE (years): |
Mean |
63.5 |
643 |
63.2 |
63.7 |
SD |
10.1 |
10.0 |
92 |
9.8 |
Range |
41-90 |
44-85 |
40-80 |
40-90 |
Gender [N (96)]: |
Female |
99 (603) |
91 (54.1) |
99(60.7) |
289 (58.4) |
Male |
65(39.6) |
77 (45.8) |
64 (39.3) |
206(41.6) |
Race [N (%)]: |
Caucasian |
137(83.6) |
135 (80.4) |
133(81.6) |
405(81.8) |
Black |
23 (14.0) |
32(19.0) |
25(15.3) |
80 (16.2) |
Other |
4(4.2) |
1 (1.0) |
5(3.1) |
10(2.0) |
Height (cm): |
Mean |
167.8 |
168.6 |
167.6 |
168.0 |
SD |
8.8 |
10.7 |
11.9 |
10.5 |
Range |
145-190 |
142-193 |
102-198 |
102-198 |
Weight (kg): |
Mean |
88.4 |
88.1 |
89.7 |
88.7 |
SD |
18.0 |
18.2 |
18.4 |
18.2 |
Range |
46-139 |
49-170 |
45-150 |
45-170 |
NSAIDs Use |
107(65.2) |
117(69.6) |
113(69.3) |
337 (68.1) |
(N,W) |
Use of Assistive |
35(213) |
34 (20.2) |
32(19.6) |
101 (20.4) |
Devices (N, %) |
Physical Therapy (N, 34) |
20 (12.2) |
17 (10.1) |
25(153) |
62 (12.5) |
Legend: cm = centimeters; kg = kilograms; SD = standard
deviation |
TABLE 4: Clinical Results
Evaluation |
Success Criteria |
Results |
100 mm VAS for pain during 50 foot walk. |
A statistically significant (alpha = 0.05) reduction on mean VAS for Hyalgan® when compared to placebo at Week 26. This difference was also to exceed one fourth of the Standard Deviation of the mean change from baseline. |
At Week 26, the difference between the Hyalgan*-treated group and the placebo-treated group adjusted means was 8.85 mm (p = 0.0043), which is a difference of approximately one-third of a standard deviation (Table 5). |
Masked Evaluator Categorical Assessment of subject pain (0=none to 5=disabled) during the 48 hours preceding visits. |
The number of Hyal^n®-treated subjects showing improvement at Week 26 was to be concordant with the VAS results, however, not required to be independently statistically significant |
At Week 26 the masked evaluator's categorical assessment of pain indicated that the Hyalgan®-treated subjects experienced less pain than the placebo-treated subjects (Table 6). |
Subjects' Categorical Assessment of pain (0=none to 5=disabled) during the 48 hours preceding visits. |
The number of Hyalgan®-treated subjects showing improvement at Week 26 was to be concordant with the VAS results; however, not required to be independently statistically significant |
At Week 26 the subjects’ categorical assessment of pain indicated that the Hyalgan®-treated subjects experienced less pain than the placebo-treated subjects (Table 7). |
Magnitude of the observed effect for Hyalgan® versus placebo on both the VAS and the categorical pain assessments. |
At Week 26 the magnitude of the observed effect for Hyalgan® versus placebo on both the VAS and the categorical pain assessments were to beat least 50% of those observed for the naproxen group. |
The improvement in pain on the VAS exhibited by the Hyalgan“-treated group relative to the placebo-treated group were at least 5096 of the benefits exhibited by the naproxen-treated group relative to the placebo-treated group. The results of the categorical assessments by the masked evaluator and the subject indicated that improvement of the Hyalgan*-treated group relative to the placebo-treated group was at least 50% of the benefits exhibited by the naproxen-treated group relative to the placebo-treated group (Table 8). |
TABLE 5: ANCOVA of 50-Foot Walk Test (mm) VAS by Week
for all Completed Subjects
|
Week |
3 |
4 |
5 |
9 |
12 |
16 |
21 |
26 |
Adjusted Means Hyalgan® |
27.23 |
21.54 |
19.29 |
20.04 |
20.26 |
20.83 |
18.44 |
17.88 |
Placebo |
32.35 |
28.57 |
25.67 |
24.28 |
26.66 |
25.44 |
24.77 |
26.73 |
Hyalgan® versus Placebo |
5.13 |
7.03 |
6.39 |
4.24 |
6.40 |
4.61 |
6.33 |
8.846 |
p-value |
0.06 |
0.01 |
0.01 |
0.1 |
0.03 |
0.1 |
0.02 |
0.004 |
TABLE 6: Masked Evaluators' Categorical Assessments of
Pain for Completed Subjects in Prior 48 Hours: Level of Pain by Treatment Group
at Baseline and Week 26
|
NUMBER (%) OF SUBJECTS IN CATEGORY |
Hyalgan® |
Placebo |
Naproxen |
Baseline |
Week 26 |
Baseline |
Week 26 |
Baseline |
Week 26 |
None (0) |
0(0.0) |
27(25.7) |
0 (0.0) |
15(13.0) |
0 (0.0) |
17(15.0) |
Slight (1) |
1 (1.0) |
23(21.9) |
0 (0.0) |
27(23.5) |
0(0.0) |
32 (28.3) |
Mild (2) |
2(1.9) |
24 (22.9) |
2(1.7) |
29 (25.2) |
2(1.8) |
27(23.9) |
Moderate 3) |
69(65.7) |
26 (24.8) |
85(73.9) |
34 (29.6) |
79(70.5) |
28 (24.8) |
Marked (4) |
33(31.4) |
5(4.8) |
28 (24.3) |
10(8.7) |
31 (27.7) |
9 (8.0) |
TOTAL |
105(100) |
105(100) |
115(100) |
115(100) |
112* (100) |
113(100) |
*One Naproxen treated subject was missing a Baseline
assessment |
TABLE 7: Subjects' Categorical Assessments of Pain for
Completed Subjects in Prior 48 Hours: Level of Pain by Treatment Group at
Baseline and Week 26
|
NUMBER (%) OF SUBJECTS IN CATEGORY |
Hyalgan® |
Placebo |
Naproxen |
Baseline |
Week26 |
Baseline |
Week26 |
Baseline |
Week26 |
None (0) |
1 (1.0) |
23(21.9) |
0 (0.0) |
14 (12.2) |
0 (0.0) |
13(11.5) |
Slight (1) |
2(1.9) |
27(25.7) |
0 (0.0) |
24 (20.9) |
1 (0.9) |
31 (27.4) |
Mild (2) |
6(5.7) |
19(18.1) |
8(7.0) |
24 (20.9) |
7(6.2) |
26 (23.0) |
Moderate (3) |
62 (59.0) |
26 (24.8) |
78 (67.8) |
40 (34.8) |
72 (63.7) |
31 (27.4) |
Marked (4) |
34 (32.4) |
10(9.5) |
29(25.2) |
13(11.3) |
33 (29.2) |
12(10.6) |
TOTAL |
105(100) |
105(100) |
115(100) |
115(100) |
113 (100) |
113 (100) |
TABLE 8: Hyalgan* Effect as a Percentage of the
Naproxen-Placebo Difference
Assessment |
Hyalgan® (HYL) |
Placebo (PLA) |
Naproxen (NAP) |
HYL-PLA |
NAP-HYL |
NAP-PLA |
(HYL-PLA) %of (NAP-PLA) |
VAS for 50 foot Walk Baseline Adjusted Mean Effect Sizes From ANCOVA |
|
|
|
-8.85 mm on a 100 mm VAS |
4,12 mm on a 100 mm VAS |
-4.73* mm on a 100 mm VAS |
187% |
% of Subjects Improved by Masked Evaluators |
78.1 |
69.6 |
73.2 |
8.5 |
-4.9 |
3.6 |
236% |
% of Subjects Improved by Subjects |
733 |
62.6 |
67.3 |
10.7 |
-6.0 |
4.7 |
228% |
*Imputed as (NAP-HYL)+(HYL-PLA).
Note that Effectiveness Success Criterion D is satisfied since ((HYL-PLA) % of
(NAP-PLA)) > 50% for all three of the above pain assessments. |