1. Pooled Source Plasma NAT for HIV-1 An Update from the Bayer HIV-1 IND Study Barbara Masecar Bayer Corporation Raleigh, NC Blood Products Advisory Committee Meeting 67th Meeting September 14, 2000

2. Bayer HIV-1 IND Study: Background IND filed with FDA August, 1999 Shared filing with Roche Molecular Systems Roche Ampliscreen TM microwell plate method Testing initiated October 1999 96-sample minipools Nucleic acid extraction from minipools shared with HCV NAT screening 2

3. Bayer HIV-1 IND Study: Assay Performance Assay sensitivity: 95% positivity at 91 IU per mL Calculated detection limit at the unit level: 8,736 IU per mL in minipools of 96 donations 3

4. Bayer HIV-1 IND Study: IND Study Design Study-eligible HIV-1 NAT-reactive donors are categorized at the time of index donation: 4

5. Bayer HIV-1 IND Study: IND Study Design Donors positive for HIV-1 p24 antigen ONLY: Investigation of donors with possible false positive/false negative results is included in IND investigational plan No known donors in the category However, amending IND to ensure identification and further testing for these donors 5

6. Bayer HIV-1 IND Study: Update Since October, 1999: 2.1 million donations screened –11 Category A donors identified (NAT pos, ag/ab neg) –3 Category B donors identified (NAT/ag pos, ab neg) –10 Category C donors identified (NAT/ab pos, ag neg) 6

7. Bayer HIV-1 IND Study: Update Follow-up study results for Category A donors (NAT pos, ag/ab neg): Subsequent sample information available on 9 of 11 identified donors 7

8. Category A donors 8

9. Conclusions Reduction in Window Period: HIV-1 NAT relative to p24: 3-7 days HIV-1 NAT relative to HIV-1/2 antibody: 10.7 days No False Positive HIV-1 NAT results seen to date (all corroborated by some other HIV-1 test result) 9