February 24, 2016 | 1 Paul Strengers MD, FFPM Sanquin Blood Supply Amsterdam The Netherlands Risk assessment schemes: Impact of regulation requirements on the viral safety of plasma derived products

February 24, 2016 | 2 Viral safety Donor selection Exclusion of high-risk groups Individual donation screening Serological and NAT testing on donations and plasma pools Virus reducing and/or inactivation processes Inventory hold Pharmacovigilance

February 24, 2016 | 3 Selection of donors and screening for markers of infection of known viruses Exclusion criteria Donations screened for pathogens using serology (ELISA) and/or PCR technologies Over the years: Increasing sensitivity of serological test kits Use of nucleic acid amplification technology (NAT) Results: Reduction of window period for HIV, HCV, HBV. Risks for the finished end products have decreased significantly

February 24, 2016 | 4 Production process General principle of EU Guideline : For obtaining a safe product, the virus inactivation and/or removal capacity should exceed the potential amount of virus that could enter the production process, thereby leading to an adequate safety margin of the finished product. However: no such safety margin has been defined ! Requirements : - For envelop viruses at least two effective steps for virus reduction with a different mode of action; for non-enveloped viruses at least one effective step. - Multiple virus reduction steps are incorporated : solvent-detergent treatment, pasteurization, virus filtration, low pH treatment, vapor heating, protein precipitation steps, hydrophobic gel chromatography.

February 24, 2016 | 5 Reporting and assessment of epidemiological data of the donor population with respect to infection risk of HIV, HCV and HBV Infectious donations below the detection limit of the test can still enter the plasma pool. Subsequently the risk of a plasma pool be contaminated can be derived from: Viral incidence rate in the donor population Local epidemiology (eg. viral genotypes) Sensitivity of the assay Not knowing the risks and limitations of the assay Window period of the specific virus Quarantine periods Plasma pool size

February 24, 2016 | 6 European Medicines Agency (EMA) Guideline on epidemiological data on blood transmissible infections. Purpose of collecting epidemiological data is to characterize the donor population with respect to : infection risk, allow trend analysis to be undertaken over periods of time allow comparison of risks between donor populations of individual collection centers. The estimated risk of infectious donations entering the plasma supply should be presented. Marketing authorization holders are now challenged to determine their own acceptable ranges for epidemiological data.

February 24, 2016 | 7 Requirements laid down in European directives for blood transfusion systems. To collect data on incidence of infectious markers of transfusion transmissible viruses in donors Aim : to ensure safe transfusion of (cellular) blood components, which depends directly on critical donor selection because of absent or limited virus removal and/or inactivation For transfusion of (cellular) blood components, the collection and assessment of epidemiological data is critical

February 24, 2016 | 8 Differences with plasma products: For plasma-derived medicinal products, the relation between a safe medicinal product and donor epidemiology is less straightforward as a result of the very effective virus removing and/or inactivating capacity of the production process.

February 24, 2016 | 9 Residual risk of virus transmission by plasma-derived medicinal products I An assessment of the (residual) risk of virus transmission by plasma-derived medicinal products requires a systematic analysis of all production steps Starts with the incidence of the infectious disease cases considered in the donor population which is the rate at which new infections occur per unit time The observed incidence rate is directly related to the likelihood that recent infections are detected by screening tests. The probability of an undetected infected donor is used to determine the risk of contaminating a production pool From the virus removal and/or inactivation capacity of various processing steps, the composition of production pools, and the number of product vials manufactured, the risk of contamination of a vial of finished product can be calculated.

February 24, 2016 | 10 Residual risk of virus transmission by plasma-derived medicinal products II In summary, the risk of viral contamination of a finished plasma-derived medicinal product depends both on the baseline risk of the plasma – and thus on the virus incidence rate in the donor population – and the ability of the production process to remove or inactivate the viruses that are present in the source plasma

February 24, 2016 | 11 Parameters used for calculating the risk of infectious disease transmission for various scenarios Process Value Plasma production pool10,000 liter Number of donations30,000 (100% recovered plasma, 330 ml) 15,000 (100% apheresis plasma, 650 ml) Product yield2,500 vials * Process reduction of HBV † 8 log 10 (minimum requirement) 12 log 10 (conservative estimate in a realistic setting) Process reduction of HAV † 4 log 10 (minimum requirement) 7 log 10 (conservative estimate in a realistic setting) VirusesHBVHAV Prevalence in general population ‡1 : 5001 : 10,000 Prevalence in new donors after selection § Incidence in repeat-tested donors 1 : 2,000 (NL: 2,300) 1 : 50,000 (NL: 69,000) 1 : 20,000 1 : 500,000 Max. virus titer w/o screening test ║10 9 IU/ml10 6 IU/ml Max. virus titer after screening test ¶25 IU/ml720 IU/ml Duration of viremia in infected donor **Continuous95 days Window period in case of NAT testing **23 days17 days

February 24, 2016 | 12 Hypothetical example: six safety scenarios that are applied to one single hypothetical production process Scenario A: no donor selection, no donation screening and no virus reduction during the production process; Scenario B1: only donor selection is in place; Scenario B2: donation screening added to donor selection; Scenario C: only virus reduction during the process; Scenario D: all safety measures (donor selection, donation screening and virus reduction during the production process) are in place; Scenario D*: as scenario D, but assuming a much higher infection incidence than occurs in reality.

February 24, 2016 | 13 HBVScenario AScenario B 1 Scenario B 2 Scenario CScenario DScenario D 0 Virus safety measureNone Donor selection only Donor selection and donation screening only Viral reduction by process only Donor selection, donation screening and process virus reduction As D, but with viral incidence of 1:100 Number of positive donations in pool 60 *15 † ‡ 1.0 § 60 * ‡ 1.0 § 19 ║ Viral contamination in production pool ¶ 2.0 x IU5 x IU 3.1 x 10 2 IU 8.3 x 10 3 IU § 2.0 x IU 3.1 x 10 2 IU 8.3 x 10 3 IU § 1.6 x 10 5 IU Viral contamination in finished product vial ** 8.0 x 10 9 IU2.0 x 10 9 IU 0.12 IU 3.3 IU § 80 IU (min) 8.0 x IU (realistic) 1.2 x IU (min) 3.3 x IU (min) § 1.2 x IU (realistic) 3.3 x IU (realistic) § 6.2 x IU (min) 6.2 x IU (realistic)

February 24, 2016 | 14 Conclusion Donor selection only (scenario B1) has only a limited effect on the residual viral risk associated with a vial of finished product, whereas addition of donation screening is more effective (scenario B2). Virus reduction during the production process has the largest impact on viral safety. Process virus reduction by itself is not sufficient to achieve a virus-safe product, with a relative high risk of transmission of HBV and HAV remaining (scenario C). If 1 IU of virus is presumed to be sufficient for disease transmission, only the combination of donor selection, donation screening and process virus reduction results in a finished product that can be considered safe with respect to virus transmission, yielding maximal viral contaminations of 3.3 x IU for HBV in a realistic production process Even in case of a high incidence rate (scenario D0), the maximal viral contamination is still acceptable, both or HBV

February 24, 2016 | 15 Discussion It is the combination of measures that define the safety of the finished product Unfortunately, there is no reference of what is an acceptable risk level of virus transmission by plasma-derived medicinal products Unless an acceptable risk level is set, discussions on the necessity of further measures to reduce this risk will continue even if the actual level is near negligible. Only if the combination of the three types of safety measures to prevent virus transmission – donor selection, donation screening, and virus removal and/or inactivation in the production process – are considered in conjunction, a proper interpretation of the safety of the finished products can be given.

February 24, 2016 | 16 In summary Virus-removing and/or inactivation procedures in the production process should sufficiently outweigh the risk of infectious diseases occurring in the donor population in order to obtain an acceptable level of risk of infectious disease transmission. The interaction between the three measures taken to prevent transmission of viruses – donor selection, donation screening, and virus removal and/or inactivation during production – need to be considered conjointly. Only then can the adequacy of measures taken to achieve an acceptable risk level for infectious disease transmission by plasma-derived medicinal products be properly assessed.

February 24, 2016 | 17 Thanks to : Sanquin :Karin Velthove Jan Over KAPQS:Kristiena Abbink UMCU, Julius Center for Health Sciences and Primary Care:Mart Jansen