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U.S. Department of Health and Human Services

Post-Approval Studies (PAS)

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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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PRODISC-L Long Term Study

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Application Number P050010 / PAS001
Current Plan Approved 08/14/2006
Study Name PRODISC-L 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 continuation of the IDE study, which was a multi-center, prospective, randomized, controlled clinical trial. The objective of PAS is to evaluate the long-term safety and effectiveness of Prodisc -L Total Disc Replacement to spinal fusion surgery in the treatment of discogenic pain associated with Degenerative Disc Disease in the lumbosacral spine.
Study Population Description Study population is as per device indication. The study population consists of all patients from IDE study who were enrolled and treated without major protocol violation. This device is indicated for spinal arthroplasty in skeletally mature patients with degenerative disc disease (DDD) at one levelfrom L3-Sl. DDD is defined as discogenic back pain with degeneration of the disc confirmed by patient history and radiographic studies. These DDD patients should have no more than Grade I spondylolisthesis at the involved level. Patients receiving the PRODISC -L Total Disc Replacement should have failed at least six months of conservative treatment prior to implantation of the PRODISC Total Disc Replacement.
Sample Size A total of 286 patients (161 randomized investigational subjects, 75 randomized control subjects, and 50 non-randomized investigational subjects) enrolled in the PAS
Data Collection The outcome measures in the PAS include patient self-assessment on Oswestry score, SF-36, Pain and satisfaction; physical & neurological examination and radiographic evaluation of the implanted level and adjacent segments. The composite overall success is defined as: - Oswestry score improves by at least 15% over baseline value;- SF-36 score will be improved; - Maintained or improved neurological parameters, i.e., motor, sensory, reflexes and straight leg raise tests; - No re-operations were required to modify or remove the implant (Prodisc -L group); no re-operations were required to modify the fusion site or correct a complication with an implant (Fusion group). - Radiological success as assessed by independent radiographic review.
Follow-up Visits and Length of Follow-up The subjects were followed at 6 weeks, 3 months, 6 months, 12 months, 18 months and 24 months post-operation in the PMA study. They will be followed annually after 24 month, up to 60 month post-operation in PAS.
Final Study Results
Interim Safety Information As of the database cut-off date, all patients in the PAS had passed the 48-month post-operation visit time point. For the Randomized ProDisc -L group, the follow-up rate dropped from 96.8% at 24-month to 62.7% (94 actual visits / 150 expected visits) at the 48-month post-operative visit. There were 2 deaths and 10 failures. The situation is similar for the Fusion group and the Non-randomized ProDisc -L group. In the Fusion group, the follow-up rate dropped from 92% at 24-month visit to 46% (32/70) at the 48-month and 57% at the 60-month post-operative visit. At the 48-month visit there were 1 death and 9 failures. For the non-randomized ProDisc -L group, the follow-up rate also dropped from 96% at the 24-month visit to 67.3% (33/49) and 75% at the 48-month and 60-month follow-up visit, respectively. At the 48-month visit there were no deaths and 1 failure.
Number of Patients 161 randomized investigational subjects, 50 training investigational subjects, and 75 control subjects. Overall 286 patients continued participation from the IDE study.
Number of Sites 17 sites were enrolled for the Post-Approval Study.
Follow-up Rate 60.2%, 60.1% and 82.5% were the overall follow up rates at 36, 48, and 60 months, respectively.
Safety Findings During the 3 years of the PAS, there were several AEs with higher occurrence in the ProDisc randomized group compared to the fusion randomized group: infection/other non wound (4 vs. 1); back pain (18 vs. 4), pain ¿ back and lower extremities (10 vs. 5), surgery other (16 vs. 7).

All AEs involving pain considered together look definitely higher in the ProDisc randomized group.

Effect Findings At month 60 non-inferiority was demonstrated for Overall Success (p=0.0099) and Overall Success (Secondary Analyses) (p=0.0101).
Strengths & Weaknesses The main strength of the study is the randomized design. The main weakness of the study is the relatively low follow up rate, especially during follow up visits before the final visit; this may partially hamper the validity of the randomized comparison, since loss to follow up may not be independent of randomization group as well as patients outcomes.
Label Changes Yes.

PRODISC-L Long Term Study Schedule

Report Schedule
Date Due
FDA Receipt
Applicant's Reporting Status
1 year report 12/24/2007 12/21/2007 On Time
2 year report 06/09/2009 06/10/2009 Overdue/Received
Final Report 09/27/2010 09/20/2010 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

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