Safety, Efficacy and Treatment Regimen Study of ST266 in Subjects With Moderate to Severe Periodontitis

Study Overview
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Brief Summary
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The purpose of this study is to determine whether ST266 will reduce pocket depth (PD) as an adjunctive to scaling and root planing (SRP) in subjects with moderate to severe periodontal disease.

Detailed Description
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The study is a 9-month, randomized, double-blind, parallel-design study of subjects with existing moderate to severe periodontal disease randomly assigned to one of three groups. The primary endpoint of PD change will be evaluated following 9 months of treatment. Subjects will be followed for 9 months for safety and radiographic evaluations. Subjects who meet inclusion criteria will be randomized to one of three treatment groups. Randomization will be stratified by site and smoker status (never smoked or quit smoking more than two years ago vs. has smoked within the last two years). Randomization will be blocked such that assignment to treatment groups both within sites and within smoker status will be approximately even (1:1:1). Treatment will be initiated after SRP. All subjects will be evaluated at baseline and Days 1, 15, 30, 60, 90, 180, and 270.

Official Title
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A Randomized, Double-blind, Placebo-controlled Study to Evaluate the Safety, Efficacy, and Treatment Regimen of ST266 in Subjects With Moderate to Severe Periodontitis

Conditions
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Periodontal Disease

Intervention / Treatment
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* Biological: ST266
* Drug: Saline (0.9% NaCl)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Provision of signed, written informed consent prior to participation in any study-related procedures. Good general health as evidenced by medical history. Between 18 and 85 years of age at time of informed consent signature. Male or female. Minimum of 18 teeth, excluding third molars. Having moderate to severe periodontal disease according to AAP definition (at least 6 teeth ≥6 mm PD and ≥3 mm CAL at baseline). Having >30 percent bleeding sites upon probing. Willing to abstain from chewing gums and other mouth rinses for the study duration. Ability and willingness to attend all study visits and comply with all study visits and comply with all study procedures and requirements. Willingness to abstain from routine dental care. For women with reproductive potential, willingness to use highly effective contraception (e.g. licensed hormonal contraception, intrauterine device, abstinence, or vasectomy in partner). Exclusion Criteria: Presence of orthodontic appliances. A soft or hard tissue tumor of the oral cavity. Any dental condition that requires immediate treatment, such as carious lesions. Participation in any other clinical study within 30 days of screening or during the study. Pregnancy or lactation. If a subject meets this criterion, she may be rescreened for study participation when she no longer meets this criterion. Antibiotic therapy within the last 30 days. Chronic use (≥3 times/week) of anti-inflammatory medications (e.g., non-steroidal anti inflammatory drugs, steroids). Low-dose aspirin (less than 325 mg daily) is allowed. Immunocompromised subjects. Subjects with cancer or a history of cancer within the last 5 years of screening. Any medical history or any concomitant medication that might affect the assessment of the study treatment or periodontal tissues, such as diabetes, nifedipine, phenytoin (Dilantin), or anticoagulant medications (e.g., warfarin [Coumadin] etc.). Involvement in the planning or conduct of the study. History of any clinically significant disease or disorder which, in the opinion of the investigator, may either put the subject at risk because of participation in the study, or interfere with interpretation of the subject's study results. Previous randomization for treatment in the present study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Group 1<br>Group 1 received ST266 treatment daily on Days 1 through 5, 8 through 12, 22, and 30, and then monthly for 7 months (Days 60, 90, 120, 150, 180, 210, and 240). | Biological: ST266<br>* 1X ST266 applied in a dose of 20 microliters per tooth. Total daily dose will be less than 1 milliliter. ST266 will be applied directly to the marginal gingiva around each tooth (buccal and lingual).<br>|
| Active Comparator: Group 2<br>Group 2 received ST266 treatment 2x/week (with at least 1 day between treatments) for the first 3 months, and then monthly for 5 months (Days 120, 150, 180, 210, and 240). | Biological: ST266<br>* 1X ST266 applied in a dose of 20 microliters per tooth. Total daily dose will be less than 1 milliliter. ST266 will be applied directly to the marginal gingiva around each tooth (buccal and lingual).<br>|
| Placebo Comparator: Group 3<br>Group 3 received commercially available sterile saline (0.9% sodium chloride) according to the same schedule as Group 1. | Drug: Saline (0.9% NaCl)<br>* Saline applied in a dose of 20 microliters per tooth. Total daily dose will be less than 1 milliliter. Saline will be applied directly to the marginal gingiva around each tooth (buccal and lingual).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Pocket Depth (PD) for Those Pockets ≥ 6 mm at Baseline | The primary efficacy endpoint of this study is the change from baseline in the PD at 9 months (Day 270) for those pockets ≥6 mm at baseline. | Baseline; 9 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Clinical Attachment Level (CAL) | Change in Clinical Attachment Level (CAL) (the measurement of the position of the soft tissue in relation to the cemento-enamel junction (CEJ) that is a fixed point, using probing depth and the distance from the gingival margin to the CEJ.) from baseline in CAL at 9 months (Day 270) in tooth sites with baseline PD ≥ 6mm. | Baseline, 9 months | 
| Bleeding on Probing (BOP) | A secondary efficacy endpoint of this study is change from baseline in BOP at 9 months (Day 270) with BOP for each subject calculated as the percentage of tooth sites in the whole mouth with BOP. | Baseline and 9 months |