CLINICAL PHARMACOLOGY
Clinical Study
Study Design
The safety and effectiveness of a single injection of
Gel-One® for the treatment of symptomatic osteoarthritis of the knee were
studied in a prospective, randomized and double-blind controlled study
conducted at 25 centers in the United States. The safety and effectiveness of a
single injection of Gel-One® was confirmed by protocol SI-6606/01.
A total of 379 patients were randomized at a 2:1 ratio of
Gel-One® (n=251) to PBS (n=128); both investigators and patients were blinded
to treatment allocation. Data collection included patientreported Western Ontario
and McMaster Universities Osteoarthritis (WOMAC) visual analog scale (VAS)
scores, Outcome Measures in Rheumatology Clinical Trials and Osteoarthritis Research
Society International responses (OMERACT-OARSI responses), physician and patient
global assessments and adverse events (AEs). The primary effectiveness analysis
was a comparison, at 13 weeks, between Gel-One® and PBS treatment groups of
change from baseline in WOMAC VAS Pain subscore, measured on a 100 mm scale.
Patient Population And Demographics
Of the 379 enrolled patients, 377 patients received either
Gel-One® or PBS injection, and 375 patients were analyzed for the Intent to
treat (ITT) population. Patients reported pain with symptomatic OA of the knee
defined by WOMAC VAS Pain subscore of > 40 mm in the study knee and < 20 mm
in the contralateral knee. Patients meeting the following criteria were
excluded at randomization; Kellgren-Lawrence Grade 4, severe inflammation or
joint effusion in either knee. The ITT population included all treated patients
who had any post-injection evaluations. Table 1 summarizes baseline and patient
demographic characteristics for the ITT population.
Treatment And Evaluation Schedule
Following an initial screening visit, eligible patients were
randomized to receive either a single injection of Gel-One® or a single
injection of PBS. Patients in both treatment groups received an intra-articular
injection in the identified knee joint at Week 0. Effectiveness and safety
measures were assessed by follow-up visits at Weeks 1, 3, 6, 9 and 13.
Patients, who used NSAIDs at stable doses over 4 weeks
prior to study injection, were allowed to continue with the same regimen.
Intermittent use of short-acting opiates was allowed during the study.
Acetaminophen was provided to patients as a rescue medication up to 4,000 mg
per day. All medication was prohibited within 24 hours prior to each evaluation
visit.
Adverse Events Summary
Among the Gel-One® treatment group (249 patients), 483
adverse events in 172 patients (69.1%) were reported. Among the PBS treatment group
(128 patients), 216 adverse events in 81 patients (63.3%) were reported. There
was no statistically significant difference in the incidence rates of adverse
events between Gel-One® and PBS treatment groups. Adverse events occurring in
more than 5% of patients in both treatment groups included joint swelling
(knee), joint effusion (knee), arthralgia (knee or hip) and upper respiratory
tract infections (Refer to Table 2).
The most common adverse events related to Gel-One®
injection reported in this study were joint swelling (14.1%), joint effusion
(11.2%), and arthralgia (7.6%).
Additional adverse events related to Gel-One® injection included
injection site pain (2.0%), joint stiffness (0.8%), muscular weakness (0.8%),
dizziness (0.8%), erythema (0.8%), effusion (0.4%), injection site bruising
(0.4%), injection site erythema (0.4%), swelling (0.4%), increased alanine aminotransferase
(0.4%), increased white blood cell count (0.4%), back pain (0.4%), muscle spasms
(0.4%), synovitis (0.4%), tension headache (0.4%), rash (0.4%), rash pruritic
(0.4%) and hypertension (0.4%) (Refer to Table 3).
There were neither serious adverse events nor pseudoseptic
reactions related to Gel-One® injection.
Clinical Effectiveness Results
The study primary endpoint, WOMAC Pain subscore at Week
13, demonstrated that Gel-One® was superior to PBS with a 6.39 mm advantage at
Week 13 in the ITT population (p=0.0374) (Refer to Table 4 and Figure 1).
Summary of secondary effectiveness results are shown in
Tables 5 and 6.
Table 1. Patient Baseline Characteristics - ITT
Population
Variable |
|
Gel-One®
(N=247) |
PBS
(N=128) |
Age (years) |
Mean (SD) |
60.9 (10.2) |
60.3 (10.0) |
Gender (n) |
Male |
100 (40.5%) |
51 (39.8%) |
Female |
147 (59.5%) |
77 (60.2%) |
K-L Score - Study Knee (n) |
1 |
21 (8.5%) |
18(14.1%) |
2 |
94(38.1%) |
47 (36.7%) |
3 |
132 (53.4%) |
63 (49.2%) |
Study Knee |
WOMAC Pain Subscore (mm) |
Mean (SD) |
70.7 (14.4) |
68.0 (13.1) |
Total WOMAC Score (mm) |
Mean (SD) |
69.5 (16.0) |
67.8 (14.7) |
WOMAC Physical Function (mm) |
Mean (SD) |
68.9 (17.4) |
67.6 (15.8) |
WOMAC Stiffness (mm) |
Mean (SD) |
71.6 (17.5) |
69.3 (17.3) |
Contralateral Knee |
WOMAC Pain Subscore (mm) |
Mean (SD) |
7.3 (5.5) |
7.6 (5.6) |
Table 2. Adverse Events Occurring in ≥ 5% of
Treated Patients
System Organ Class |
Preferred Term |
Gel-One®
(N=249) |
PBS
(N=128) |
Musculoskeletal and connective tissue disorders |
Joint swelling (knee) |
70 (28.1%) |
36 (28.1%) |
Joint effusion (knee) |
58 (23.3%) |
33 (25.8%) |
Arthralgia (knee/hip) |
44 (17.7%) |
15 (11.7%) |
Infections and infestations |
Upper respiratory tract infections |
16 (6.4%) |
6 (4.7%) |
Table 3. Adverse Events Related to Study Treatment
System Organ Class |
Preferred Term |
Gel-One®
(N=249) |
PBS
(N=128) |
Musculoskeletal and connective tissue disorders |
Joint swelling (knee) |
35 (14.1%) |
15 (11.7%) |
Joint effusion (knee) |
28 (11.2%) |
13 (10.2%) |
Arthralgia (knee/hlp) |
19 (7.6%) |
12 (9.4%) |
Joint stiffness (knee) |
2 (0.8%) |
1 (0.8%) |
Muscular weakness (knee) |
2 (0.8%) |
1 (0.8%) |
Back pain |
1 (0.4%) |
1 (0.8%) |
Joint warmth (knee) |
0 |
1 (0.8%) |
Muscle spasms (knee) |
1 (0.4%) |
0 |
Synovitis (knee) |
1 (0.4%) |
0 |
General disorders and administration site conditions |
Injection site pain |
5 (2.0%) |
1 (0.8%) |
Effusion |
1 (0.4%) |
1 (0.8%) |
Injection site erythema |
1 (0.4%) |
1 (0.8%) |
Injection site bruising |
1 (0.4%) |
0 |
Swelling |
1 (0.4%) |
0 |
Skin and subcutaneous tissue disorders |
Erythema |
2 (0.8%) |
0 |
Rash |
1 (0.4%) |
0 |
Rash pruritic |
1 (0.4%) |
0 |
Nervous system disorders |
Headache |
0 |
2 (1.6%) |
Dizziness |
2 (0.8%) |
0 |
Burning sensation |
0 |
1 (0.8%) |
Tension headache |
1 (0.4%) |
0 |
Investigations |
Increased alanine aminotransferase |
1 (0.4%) |
0 |
Increased white blood cell count |
1 (0.4%) |
0 |
Vascular disorders |
Hypertension |
1 (0.4%) |
0 |
Ear and labyrinth disorders |
Hearing impaired |
0 |
1 (0.8%) |
Infections and Infestations |
Cellulitis |
0 |
1 (0.8%) |
Injury, poisoning and procedural complications |
Contusion |
0 |
1 (0.8%) |
Figure 1: Improvement from Baseline in WOMAC VAS Pain
Subscore at Week 13 - ITT Population
Table 4. WOMACa VAS Pain Improvement from Baseline at
13 weeks ( ITT Population (N=375))b
Assessed Time-point |
Model-Estimated Advantage (Gel-One® - PBS) |
Two- sided Lower 95% Confidence Limit (mm) |
Two-sided P-value |
At Week 13 |
6.39 mm |
0.37 |
0.0374 |
a The Western Ontario and McMaster
Universities Osteoarthritis Index (WOMAC) is a set of standardized
questionnaires used by health rofessionals to evaluate the condition of
patients with osteoarthritis of the knee and hip. WOMAC Pain Scale is 100mm.
b The analysis is based on the quadratic spline model at knot of 6
weeks and at week 13 for the primary endpoint. |
Table 5: OMERACT-OARSI Responsesa - ITT Population
Odds Ratiob |
Two-sided Lower 95% Confidence Limit of Odds Ratioc |
Two-sided P-valued |
1.27 |
0.85 |
0.2418 |
a A subject was considered an OMERACT-OARSI
'responder1 if either of the following 2 criteria were met:
(1) his or her reported improvement from baseline in WOMAC VAS Pain subscore or
WOMAC VAS Physical Function subscore was at least 50% and the absolute change was at least 20 mm, or
(2) his or her reported improvement from baseline was at least 20% and the
absolute change was at least 10 mm for at least 2 of the following 3 measures:
(a) WOMACVAS Pain subscore,
(b) WOMAC VAS Physical Function subscore,
(c) Subject Global Evaluation.
b e (Log Odds Ratio)— 1 2 7 , based on GEE model
(Log Odds Ratio)=loge [probability(responder)/ probability
(non-responder)]Gei-one / [probability (responder)/
probability(non-responder)]pBs
c When odds ratio > 1, [probability(responder)/ probability
(non-responder)Gei-one] > [probability (responder)/ probability
(non-responder)pes] and thus in favor of Gel-One.
d Statistically not significant |
Table 6: Summary of Secondary Effectivenessa Endpoints
at Week 13 - ITT Population
Effectiveness Measuresb |
Model-Estimated Advantage (Gel-One® - PBS) |
Two-sided Lower 95% Confidence Limit (mm) |
Two-sided P-valuec |
Total WOMAC Score |
5.64 mm |
-0.20 |
0.0583 |
WOMAC Stiffness |
4.91 mm |
-1.31 |
0.1216 |
WOMAC Physical Function |
5.42 mm |
-0.47 |
0.0714 |
a Based on the quadratic spline model at week
13.
b WOMAC Scale is 100mm.
c P-value was not adjusted for multiplicity of secondary endpoints. |