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U.S. Department of Health and Human Services

Post-Approval Studies (PAS) Database

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The FDA has the authority to require sponsors to perform a post-approval study (or studies) at the time of approval of a premarket approval (PMA), humanitarian device exemption (HDE), or product development protocol (PDP) application. Post-approval studies can provide patients, health care professionals, the device industry, the FDA and other stakeholders information on the continued safety and effectiveness (or continued probable benefit, in the case of an HDE) of approved medical devices. This database allows you to search Post-Approval Study information by applicant or device information.

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LIBERATE Extension Study

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Study Status Progress Adequate
Application Number /
Requirement Number
P180002 / PAS001
Date Original Protocol Accepted 09/25/2018
Date Current Protocol Accepted 01/28/2019
Study Name LIBERATE Extension Study
Device Name Zephyr Endobronchial Valve System
General Study Protocol Parameters
Study Design Prospective Cohort Study
Data Source New Data Collection
Comparison Group Device Subjects Serve as Own Control
Analysis Type Descriptive
Detailed Study Protocol Parameters
Study Objectives This is a multi-center, prospective, single-arm cohort study to evaluate long-term safety and long-term effectiveness in the continued follow-up of the premarket cohort for the LIBERATE Pivotal Trial.
Study Population Subjects who were previously implanted with the Zephyr Endobronchial Valve System and participated in the LIBERATE Pivotal Trial i.e. initial cohort and crossover subjects.
Sample Size Approximately 142 subjects are available for extended follow-up
Key Study Endpoints Effectiveness Endpoint: FEV1
Safety Endpoint: Evaluation of adverse events, summarized by seriousness, severity, and relatedness.
Follow-up Visits and Length of Follow-up Follow-up is planned for five years from the date of implant procedure
Interim or Final Data Summary
Interim Results The improvement in lung function as assessed by FEV 1 that was observed at 3-year post-procedure after treatment with the Zephyr EBV is maintained at 4 -years. The change from Baseline to 4-years post-procedure in FEV1 is an increase of 17.67% with 36.4% of the subjects achieving an improvement of equal to or greater than 15%. Improvement in FEV1 is maintained in subjects at 5-year post-procedure with an increase of 19.93% from baseline with 30% of subjects achieving an improvement of equal to or greater than
Actual Number of Patients Enrolled 190
Actual Number of Sites Enrolled 24
Patient Follow-up Rate 89% (172/190 excluding deaths and withdrawals
Study Strengths & Weaknesses This study met the primary endpoint of improvement in FEV 1. High pneumothorax

LIBERATE Extension Study Reporting Schedule

Reporting Schedule
Date Due
FDA Receipt
Applicant's Reporting Status
6 month report 12/28/2018 12/21/2018 On Time
1 year report 06/29/2019 06/28/2019 On Time
2 year report 06/28/2020 06/25/2020 On Time
3 year report 06/28/2021 06/28/2021 On Time
4 year report 06/28/2022 06/28/2022 On Time
5 year report 06/28/2023    

Contact Us

Mandated Studies Program
Food and Drug Administration
10903 New Hampshire Ave.
Silver Spring, MD 20993-0002
Email: MandatedStudiesPrograms@fda.hhs.gov

Additional Resources