• Decrease font size
  • Return font size to normal
  • Increase font size
U.S. Department of Health and Human Services

Post-Approval Studies (PAS)

  • Print
  • Share
  • E-mail

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.

Learn more...


Long-Term Study

Suggest Enhancement / Report Issue | export reports to excelExport to Excel
Study Status Completed
Application Number P060018 / PAS001
Date Current Protocol Accepted 07/16/2007
Study Name Long-Term Study
General Study Protocol Parameters
Study Design Randomized Clinical Trial
Data Source New Data Collection
Comparison Group Concurrent Control
Analysis Type Analytical
Study Population Transit. Adolescent B (as adults) : 18-21 yrs, Adult: >21
Detailed Study Protocol Parameters
Study Design Description This is a prospective cohort to continue follow-up of the subjects who participated in (1) the IDE premarket study and (2) the continued access arm and metal ion study.
Study Population Description The study include IDE, CAS and metal ion study subjects. This device is indicated in skeletally mature patients for reconstruction of the disc from C3-C7 following single-level discectomy for intractable radiculopathy and/or myelopathy. Intractable radiculopathy and/or myelopathy should present with at least one of the following items producing symptomatic nerve root and/or spinal cord compression which is documented by patient history (e.g., pain [neck and/or arm pain], functional deficit, and/or neurological deficit), and radiographic studies (e.g., CT, MRI, x-rays, etc.): 1) herniated disc, and/or 2) osteophyte formation. The PRESTIGE 9 device is implanted via an open anterior approach.
Sample Size A minimum of 200 patients (minimum of 100 patients each from control and PRESTIGE groups) at 7-year follow-up
Data Collection A patient will be considered an overall success if all of the following conditions are met:

1. Postoperative Neck Disability Index score improvement of at least a 15-point increase from preoperative;

2. Maintenance or improvement in neurological status from preoperative;

3. Functional spinal unit height success;

4. No serious adverse event classified as implant associated or implant/surgical procedure associated; and

5. No additional surgical procedure classified as a "failure".

Follow-up Visits and Length of Follow-up Postoperative data will be collected at 3, 5, and 7 years
Interim or Final Data Summary
Interim Safety Information Between initial surgery and the 60 months visit, there were 1098 adverse events (AEs) reported in 249 investigational patients (90.2%) and 932 AEs reported in 227 control patients (85.7%). Among SAEs (serious adverse events) in the investigational group there were a total of 256 SAEs reported in 127 patients (46.0%) and there were a total of 185 SAEs in 110 control patients (41.5%).
Actual Number of Patients Enrolled 600 (100%)
Actual Number of Sites Enrolled 31 (100%)
Patient Follow-up Rate The sponsor was expected to follow a minimum of 200 patients (minimum of 100 patients each from control and PRESTIGE groups) through 7-year follow-up, at 31 study sites. The sponsor has followed-up

228 (84.8%) investigational and 199 (80.9%) control patients through year 7. However, the follow-up is lower, when availability of data on Functional Spinal Unit (FSU) if taken into account, n=168 (62.5%) and n=135 (54.9%) for the investigational and control patients, respectively.

Final Safety Findings In terms of cumulative adverse events n=259 (97.7%) of investigational patients had an adverse event

during the study as compared to n= 232 (94.5%) of control patients (pWilcoxon=0.722). For neck the time-to-event analysis, the cumulative rate is 70.2% and 64.7% for the investigational and control groups, respectively, with pWilcoxon = 0.070.

Further, no adverse local tissue reactions (ALTR) were observed in 6 explanted investigational devices. However, four (n=4) explanted devices showed greater than anticipated wear rate (derived from bench studies).

In the metal ion group of the investigational device patients (n=34), the Chromium levels were higher than pre-operative levels, but about 41 fold less than undesired level (7 ng/ml)

Final Effect Findings The primary end-point for the study was overall success-a composite of safety and effectiveness. Hundred twenty two (n=122) out of 168 or 72.6% of investigational patients have reached overall success. In comparison, 81 (60%) out of 135 control patients have reached overall success, p (non- inferiority)<0.001. Please refer to the table below for additional information.
Study Strengths & Weaknesses This study provided much needed information on the Prestige long term (7-years) performance. However, the findings and interpretation of this study are limited due to the observed high loss to the follow-up. A total of 108 study subjects in the investigational group and 130 in the control group have missing data on the overall success with FSU at 84 months. Additionally, 64 study subjects in the investigational group and 83 in the control group have missing data for overall success without FSU at

84-month. Furthermore, 48 study subjects in the investigational group and 66 in the control group have no 84-month data. The high proportion of loss to follow-up can introduce bias in the rate estimates, possibly due to differences in loss to follow-up between patients with different overall success at 24- months. For example, study subjects who completed the PAS in Prestige group were more likely to have achieved overall success at 24-month; whereas, study subjects in the control group who did not achieve overall success at 24-month were more likely to complete the PAS. This suggests differential loss to the follow-up between treatment groups, which limits the interpretation of the study results. Trends for several of the other study outcomes were similar.

Recommendations for Labeling Changes Yes: Long term data on the device safety and effectiveness is available and the labeling should include additional information on the long term device performance; (2) Higher than predicted wear during bench testing was observed in the explanted devices after long-term use.

Long-Term Study Schedule

Report Schedule
Date Due
FDA Receipt
Applicant's Reporting Status
6 month report 01/14/2008 01/14/2008 On Time
1 year report (Long-Term Study) 07/31/2008 07/31/2008 On Time
18 month report (Long-Term Study) 01/13/2009 01/12/2009 On Time
2 year report (Long-Term Study) 08/15/2009 08/14/2009 On Time
3 year report (Long-Term Study) 07/15/2010 07/15/2010 On Time
4 year report (Long-Term Study) 07/15/2011 08/15/2011 On Time
5 year report (Long-Term Study) 07/14/2012 07/13/2012 On Time
6 year report (Long-Term Study)-FINAL 07/14/2013 07/17/2013 Overdue/Received
final report 11/14/2013 11/14/2013 On Time
response to R32 A5-final report 08/12/2015 08/12/2015 On Time

Contact Us

Julie Unger
Project Manager, Post-Approval Studies Program
Food and Drug Administration
10903 New Hampshire Ave
WO66-4206v Silver Spring, MD

Phone: (301) 796-6134
Fax: (301) 847-8140

Related Links