MM-1 FDA Advisory Committee April 26, 2001 KETEK ™ (telithromycin)
FDA Advisory Committee Meeting
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Transcript of FDA Advisory Committee Meeting
FDA Advisory Committee MeetingTransmissible Spongiform EncephalopathiesOctober 14, 2004
Steve Figard, Ph.D.Senior Scientist
Abbott Diagnostics
And a Host of Others…
Performance of the Enfer TSE Test with
Front End Automation
Overview
Brief Overview of the Enfer TSE AssayAutomation of “Front End”Brief Data Review – External Evaluation
– Specificity– Sensitivity– Autolyzed Samples
Enfer Assay Overview
Sample Preparation
Cut tissue
Homogenize
Clarify in centrifuge plate
Immune Reactions
Primary anti-PrP rabbit polyclonal
Secondary goat anti-rabbit IgG-HRP
Sample Treatment
Transfer to test platePK digestion of PrPc
nonspecific adsorption of PrPSc
NaCl wash
GuHCl/NaOH incubation
Signal Generation
Add substrate
Read signal
Front End Automation
USDA-APPROVED ENFER TESTAutomation of “Front End”
Safer Sample Cutting
– new plastic tool
Faster Sample Homogenization
– new automated instrument
Easier Sample Handling
– new tube replaces bag
Streamlined Sample Processing
– minimized transfer
Same High Performance
SAFER SAMPLE CUTTING
Plastic PunchBladereplaced by
• No sharps• Standard cuts
• Easy disposal• Rapid
• Inexpensive
TubeBagreplaced by
EASIER SAMPLE HANDLING
Time To Process 8 Samples:
2 Stomachers – 240 seconds (4 minutes) 1 ETDS – 10 seconds
ETDS VIIIStomacherreplaced by
FASTER SAMPLE HOMOGENIZATION
STREAMLINED SAMPLE PROCESSINGSame Tube Moves Through Process
Final component ofnew automation
Streamlined Sample Processing withTecan Genesis RSP
Automated sample pipetting– ETDS tube to centrifuge plate– centrifuge plate to test plate
Automated addition of EB2 (PK) to test plateApproximately 5 min for one plate (44 samples)ETDS VIII racks fit directly into TecanOther “standard” features of automation
– disposable tips – no cross contamination
– liquid detection system for tips– bar code reader (POSID)
HIGH PERFORMANCESpecificity Testing - LGC
HIGH PERFORMANCESensitivity/Autolyzed Samples
200 positive samples from OTM population– collected and frozen at least a year and in good condition– confirmed by BioRad/Prionics WB
200 negative samples from fallen stock– in state of “severe autolysis” – worst case sample type– confirmed by BioRad/Prionics WB
Autolyzed samples can have high levels of protease inhibitors which can affect Proteinase K digestion and possibly result in a false positiveAll samples were supplied as homogenates, not tissueTesting done at Veterinary Laboratories Agency, Newcastle, UK
HIGH PERFORMANCESensitivity/Autolyzed Samples
Positive vs. Negative (Autolyzed) Sampleswith Enfer Front End Automation
(n = 200 for each population)
Bins - S/CO's
0.0 1.020
0.040
0.060
0.080
0.010
00.0
1200
.0
Freq
uenc
y
012345
20
40
60
80
100
120
140
160
180
Neg (Autolyzed) Positives Cu
toff
Negative (Autolyzed) Positive
Mean 0.026 327Median 0.013 287
SD 0.073 -Range -0.114 - 0.899 12.3 - 1217
SD from Mean to Cutoff 13.3 -
100 % Sensitivity100% Specificity
in this samplepopulation
Questions?