E B—Anti-HBc Chart 1 10/2004 Anti-HBc Testing and Donor Reentry Results of a Pilot Study Susan L. Stramer, Ph.D. American Red Cross Blood Products Advisory Committee Meeting Nov 4, 2005 (update from Oct 21, 2004 meeting) In collaboration with: National Genetics Institute and Abbott Laboratories

E B—Anti-HBc Chart 2 10/2004 Anti-HBc Testing Background uHistorical/present RR rates range from 0.4%-1.6% –False positivity high 25-87% reported25-87% reported dependent on specificity of test useddependent on specificity of test used uNo confirmatory/supplemental tests –1X anti-HBc RR may donate again; impact of RR notification –2X anti-HBc RR deferred uHistorical number of deferred donors who lack other deferral codes –> 200,000 April 1991-Dec 2003 –> 500,000 nationwide since Feb 1987

E B—Anti-HBc Chart 3 10/2004 Anti-HBc Testing Background uCan an algorithm be validated to reenter deferred donors who are falsely anti-HBc reactive? uIf so, what would be the yield of reentry? uUnanimous support from BPAC (Oct 21, 2004) for validation of a reentry algorithm –Test a follow up sample by: Highly sensitive HBV DNA assay (<10 copies/mL)Highly sensitive HBV DNA assay (<10 copies/mL) “Alternate” anti-HBc assay having improved specificity“Alternate” anti-HBc assay having improved specificity (and HBsAg) (and HBsAg) Above tests must be negativeAbove tests must be negative

E B—Anti-HBc Chart 4 10/2004 Anti-HBc Testing Project Yield Based on Current 2X Reactive Algorithm u3.9 million donors (6.5 million donations) from 2000 studied –0.64% anti-HBc overall repeat reactive rate 1.37% from FT/0.24% from RPT donors1.37% from FT/0.24% from RPT donors u75% 1X anti-HBc reactive donors became 2X on next donation (plus another 13% over next 3 years) –88% FT and 38% RPT uAnti-HBc reentry algorithms projected to have higher yields if a “different” test is introduced; i.e., blood system converts to a different method

E B—Anti-HBc Chart 5 10/2004 Mean RR by NTL (FY2006) NTL Percent N NTL Percent N NTL Percent N Reactive Rates for Anti-HBc (Ortho) through July 2005 Mean RR = 0.39Total N = 1,142,470Mean IR = 0.54 DET ,547 CHA ,840PHL ,895 STL ,655POR ,533 Percent Month ( ) ’96 ’97 ’98 ’99 ’00 ’01 ’02 ’03 ’04 ’05

Anti-HBc Results from Hema-Quebec Ortho Abbott PRISM* *without reductant

E B—Anti-HBc Chart 7 10/2004 Anti-HBc RR Donation PCR Testing (NGI) Pilot Study u3000 anti-HBc RR unlinked donations selected in 2001 for further testing by NAT (HBV PCR at NGI) –Surplus NAT samples in PPTs (limit contamination) –Criterion for inclusion was nonreactive by all other test methods –No preselection of 1X versus 2X anti-HBc RRs 3000 chosen to allow a large enough sample size to include significant numbers of 2X RR donors3000 chosen to allow a large enough sample size to include significant numbers of 2X RR donors –23.6% of ARC donors over a comparable time were 2X anti-HBc RR –Approx 708 of 3000 were 2X anti-HBc RR

E B—Anti-HBc Chart 8 10/2004 Anti-HBc RR Donation PCR Testing (NGI) Pilot Study uSamples tested individually by HBV DNA –UltraQual 8-rxn, 0.2-mL input –Reactivity in any of 8 tests = Positive –Sensitivity 9 IU/mL Conversion 3.44 copies/IU = 31 copies/mLConversion 3.44 copies/IU = 31 copies/mL u19/3000 (0.63%) samples reactive –11 < 100 copies/mL Average of 1.7 per 8 reactions reactiveAverage of 1.7 per 8 reactions reactive –8 with viral loads of copies/mL; mean Average of 4.75 per 8 reactions reactiveAverage of 4.75 per 8 reactions reactive

E B—Anti-HBc Chart 9 10/2004 HBV DNA in “anti-HBc-only” units Sample dates No. tested 3953,000 3,956 No. DNA-pos Rate:Calc’tedDirect per HBc-pos 0.24%0.63% 0.35% per tx unit 1:49,0001:37,000 1:54,000 Viral Load (copies/mL) all < 10068% < % MP- NAT (-) ParameterREDSARCRoche

E B—Anti-HBc Chart 10 10/2004 Anti-HBc RR Donation PCR Testing (NGI) Pilot Study u3000 samples tested by Abbott PRISM anti-HBcore using licensed lots –Study initiated following qualification of PPTs on the PRISM and availability of “licensed” lots –Assumption is that 19 HBV DNA positives would be PRISM anti-HBc reactive –Anti-HBc nonreactive/DNA negative samples would represent “eligible donors” for reentry Testing completedTesting completed –Anti-HBc reactives investigated for anti-HBc IgM anti-HBs as samples volume allows Study ongoingStudy ongoing

ReactiveNon- Reactive Total Positive 19*019 Negative ** 2335 (79%) 638 (21%) 2973 Total * Mean S/CO = 0.14 (range ); S/CO < 1.00 = Reactive ** 7 Samples PCR Negative; PRISM HBcore QNS PRISM HBcore NGI HBV UltraQual 1000

PCR (NGI) PRISM HBcore (S/CO < 1.00=Reactive Qual SuperQuant (copies/mL)Pos Rx (out of 8)S/CO 1S/CO 2S/CO 3 ARCHBV-SL093Positive ARCHBV-SL057Positive ARCHBV-DT628Positive < ARCHBV-S2089Positive ARCHBV-D2017Positive < ARCHBV-S2061Positive ARCHBV-SD783Positive ARCHBV-SL333Positive < ARCHBV-DT312Positive ARCHBV-DT664Positive < ARCHBV-DT178Positive < E (QNS) ARCHBV-SD687Positive < ARCHBV-SL169Positive ARCHBV-SL297Positive < ARCHBV-DT483Positive < ARCHBV-DT142Positive < ARCHBV-SL244Positive < ARCHBV-DT588Positive ARCHBV-SD784Positive <

E B—Anti-HBc Chart 13 10/2004 Summary and Conclusions uPreliminary data indicate feasibility of anti-HBc reentry algorithm –All 19 HBV DNA-positive samples detected as reactive by Abbott PRISM anti-HBcore ChLIA –All 19 strongly anti-HBc reactive Mean S/CO = 0.14 (range )Mean S/CO = 0.14 (range ) uYield of reentry dependent on prior assay –25% for Ortho => Ortho (1X=>2X) –21% for Ortho => PRISM (pilot study) –40% for Ortho => PRISM (Hema-Quebec) –?? for Corzyme (prior Abbott) => PRISM

E B—Anti-HBc Chart 14 10/2004 Subsequent Studies uApprox 5000 deferred donors (2X, with anti-HBc as only deferral criterion and HBV DNA negative) from Oct 04-Sept 05 invited to provide follow-up sample under NGI’s HBV IND –Testing: HBV DNA (NGI; 5 copy/mL sens), HBsAg, anti-HBc (Ortho; PRISM pending), anti-HBs Study will convert to Roche’s IND using FDA proposed anti-HBc reentry algorithmStudy will convert to Roche’s IND using FDA proposed anti-HBc reentry algorithm –Licensed PRISM anti-HBcore and HBsAg; nonreactives tested by investigational Roche HBV DNA protocol –10% eligible donors have provided a follow up sample 66% “past” HBV infection; leaves 44% for reentry66% “past” HBV infection; leaves 44% for reentry Yield dependent on PRISM anti-HBcore reactivity, but due to low participation rate, maximum is 4.4%Yield dependent on PRISM anti-HBcore reactivity, but due to low participation rate, maximum is 4.4%

E B—Anti-HBc Chart 15 10/2004

Reactive = 2994 (79%) Nonreactive = 782 (21%)  HBV DNA Positives

N% of 3776% of Rx Reactive % Repeat Reactives % Initial Reactive Only (rpt QNS)50.13%0.17% S/CO Min (1 st retest)0.99 S/CO Max0.01 S/CO Mean0.23 N% of 3776% of NRx Non-Reactive % Non-Reactive % Initial Reactive (rpt nonreactive)110.29%1.41% S/CO Min1.89 S/CO Max1.01 S/CO Mean1.47

Anti-HBc RR Units Tested by HBV PCR (NGI) anti-HBc RR donations tested by HBV PCR (N = 31,914) HBV PCR Pos N = 2,669 (8.4%) 1,002 (38%) HBsAg Confirmed Pos 1,667 (62% or 5.2% total) HBsAg NR