1. Blood Products Advisory Committee Meeting April 26, 2007 Ben Marchlewicz, Ph.D. PRISM R&D, Program Manager

2.  Abbott’s approach to Chagas Testing  PRISM Chagas  Description of the assay  Performance  Chagas Confirmatory  Description of the assay  Performance

3. Abbott’s Strategy in Blood Screening for Chagas Disease Develop a recombinant antigen based assay for antibodies to T. cruzi on the PRISM platform  Well-characterized antigens  Presenting multiple epitopes  Non-biohazardous Develop a recombinant antigen based Confirmatory assay for resolution of PRISM Repeat Reactive specimens.

4. PRISM Chagas Assay

5. PRISM Chagas Screening Assay Design Configuration Dual rAg Coated  P, Single mAb Conjugate, Two–Step Assay

6. Multi-epitope rAg Amino acidsMol. Wt. (Kda) TcF858.3 FP369376 FP6994110 FP1072278 Multi-epitope Recombinant Antigens used in PRISM Chagas Assay

7. Specificity StudyTotal Repeatedly Reactive Confirmed Positive Resolved Specificity In-House Feasibility Testing 7,75541 99.96% Field Study4,10083 99.88% Total11,855124 99.93% Random Donors

8. Specificity StudyTotal Specificity Leishmania visceral (sourced from India) 30100% Leishmania cutaneous (sourced from India) 11100% Malaria10100% Cross Reactivity with other Parasitic Infections

9. PRISM Chagas Assay Sensitivity Chagas Positive Specimens (confirmed by RIPA) RIPA Positive RIPA Negative PRISM Positive 419 0 PRISM Negative00 Sensitivity 100% Sensitivity

10. Chagas Confirmatory Assay

11. Design of Chagas Confirmatory Immunostrip Anti-hIgG (Sample Addition CTL) hIgG-H CTL hIgG-L CTL (Cut-off) 4 rAgs for anti-T. cruzi detection TcF FP3 FP6 FP10 ID# Test BandsOn-board CTL bands

13. Visual Reading of Test Bands IntensityScore Absent - Faint or < on-board hIgG-L CTL +/- = on-board hIgG-L CTL 1+ Between on-board hIgG-L CTL and hIgG-H CTL 2+ = on-board hIgG-H CTL 3+ > on-board hIgG-H CTL 4+

14. Sensitivity RIPA Positive RIPA Negative Immunoblot Chagas Confirmatory Positive 410*0 Immunoblot Chagas Confirmatory Negative 00 100% Sensitivity * Also reactive in PRISM Assay & 2 reference ELISA’s

15. Country of Origin# of Samples Argentina 41 Bolivia53 Brazil176 Chile5 Colombia1 Ecuador1 El Salvador12 Honduras4 Mexico33 Nicaragua17 Surinam1 USA4 Venezuela21 Unknown41 Chagas Specimens Panel n = 410 (All are confirmed RIPA positive)

16. Specificity RIPA Positive PRISM Chagas Assay Non-reactive Immunoblot Chagas Confirmatory Positive 1*0 Immunoblot Chagas Confirmatory Negative 0500 100% Resolved Specificity Unscreened Random Blood Donors * Also reactive in PRISM Assay & 2 reference ELISA’s

17. Specificity RIPA Positive PRISM Chagas Assay Non-reactive Immunoblot Chagas Confirmatory Positive 2*0 Immunoblot Chagas Confirmatory Negative 0316 100% Resolved Specificity Unrelated Medical Conditions * Also reactive in PRISM Assay & 2 reference ELISA’s

18. Specificity StudyTotal Specificity Leishmania visceral (sourced from India) 30100% Leishmania cutaneous (sourced from India) 11100% Malaria10100% Cross Reactivity with other Parasitic Infections

19. Summary A fully automated blood screening assay for antibodies to T. Cruzi, on the PRISM system, is under development; Along with an Immunoblot Confirmatory assay, that can be performed on site, to confirm Repeat Reactive specimens to aid in donor management.