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Douglas C. Lee, PhDPlasma Protein Therapeutics Association

BPAC April 2011

Plasma Protein Therapies

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Plasma derived therapies;Manufacturing sites in USA

Plasma derived therapies andRecombinant therapies;Manufacturing sites in USA, Austria, Belgium, Switzerland, and Italy

Plasma derived therapies;Manufacturing site inGermany and in USA

Plasma derived therapies;Manufacturing sites in Italy

Plasma derived and Recombinant therapies;Manufacturing sites inUSA, Switzerland, and Germany

Plasma derived therapies;Manufacturing sites inSpain and USA

Plasma derived therapies;Canadian Based(North America Regional Member Only)

PPTA Members

Plasma Protein Therapies are special

• The starting material is human plasma• Individual product classes (Immunoglobulin, clotting

factors) are separated in a complex manufacturing process

• They are stable products with a defined shelf life of several years

• They are global, i.e. distributed throughout the world• Plasma protein therapies are distinct from the labile

blood components used for transfusion• They are among the most highly regulated medicinal

products

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Rel

ativ

e ris

k

From the donor public to the patient

Finished product

Virus inactivation / removal steps

NAT testing

Testing donations

Inventory Hold

Donor selection

Donor population

www.pptaglobal.org

Standards and Certification / Pathogen Safety Systems

Overview of Pathogen Safety Systems

Step 5:Virus InactivationVirus Removal

Step 7:Packaging Control

Step 1Donor Screening, serological test on individual donations

Step 2Donation Testing Nucleic Acid Technology (NAT), VMT

Step 3Inventory Hold and Lookback

Step 4Plasma Pool Testing

In-process control

Steps 6:Quality Assurance GMP

Step 8:Post-Marketing Surveillance

Steps 1 to 5: reduction of theoretical virus risk

Testing1.5

Reduction

> 9

Risk reduction (log10)S

election

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Pathogen Safety

The Safety Tripod

Virus inactivation/removal is themost effective safety measure and is designed to inactivate/remove a wide range of viruses

robustness model viruses

PPTA Member Companies Testing Strategies

Overview Pathogen Safety Testing Paradigm

Donation Testing Production Pool Testing•Quality Control point

Fra

ctio

nat

ion

Viral Marker Tests on individual donations

HBV surface antigenHIV-1 & HIV-2 antibodyHCV antibody

Viral Marker TestsHBV surface antigenHIV-1 & HIV-2 antibody

Nucleic Acid Testing HBVHIVHCV

NAT Minipool Testing

NAT HBVHIVHCV

Remove Positive Units

PPTA Member Companies Risk Reduction Strategies

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Virus Safety

Viral Inactivation and Removal: • Effective in eliminating HIV, HBV, HCV and other

blood-borne infectious agents

Validation:• Provide evidence that selected steps of the

manufacturing process effectively inactivate/remove viruses

• Provide indirect evidence that the manufacturing process will inactivate/ remove a wide range of viruses including (emerging) enveloped and non-enveloped viruses of diverse physico-chemical characteristics

Solvent/Detergent

Pasteurization

Dry heat

Low pH

Methods of Virus Inactivation and Removal

Caprylate

Precipitation

Chromatography

Nanofiltration

Risk Reduction Method Selection is Dependent on the Virus’ Physical and/or Chemical Nature and Should Not Impact Product Attributes. For HBV, both its size and susceptibility to inactivation agents are readily considered when assessing a removal step.

3. Measure total infectious virus in input and output fractions and calculate a log reduction value (LRV)

Virus Clearance Experiments

1. Add virus to Input Load

Input Fraction

Output Fraction

Scale-down model

2. Process spiked material using a bench scale model of the production step

Example:

Total Input = 105 viruses

Total Output = 101 viruses

Reduction = 105/101 = 104

LRV = Log10 104 = 4

Input virus (spiked into experiment)

Residual virus (leftover after process step)

Log Virus Reduction (LRV)

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The model virus concept, i.e. using a panel comprised of a wide range of physicochemically diverse viruses for the validation of virus reduction steps, with the goal to predict the behavior of a specific virus of interest, such as HBV.

For HBV, a practical, relevant (specific) model virus is not available.

Nevertheless, for some virus inactivation/removal steps Herpesviruses (PRV and others) have been used as unspecific model viruses since they share some structural characteristics (enveloped, DNA viruses)

The Model Virus Concept

HBV: Physical and Chemical Characteristics

Polymerase protein

Core proteins --HBcAg and HBeAg Lipid envelope

HBV DNA

Envelope glycoprotein(HBsAg)

• Family Hepadnaviridae• Lipid enveloped virus• Spherical, 40 to 48 nm diameter• Relaxed circular, partially ds DNA genome, 3.0 to

3.3 kb • Genome associated with the polymerase protein

and an electron-dense nucleocapsid composed of the core antigens, HBcAg and HBeAg

• Low resistance to physicochemical agents• solvent/detergent mixtures (TNBP/polysorbate 80)

• non-ionic detergents (Triton X-100)• caprylate• heat treatment

Example of a Panel of Model Viruses

No simple in vitro assay system exists to directly model HBV inactivation/removal in scaledown studies, therefore a panel of model viruses is used that have physical and chemical attributes similar to HBV.

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Examples for Overall HBV Reduction Factor (log10)

Factor VIII concentrates

Company

VirusA B C D E

HSV-1 > 15.2 > 9.3

PRV > 11.3 > 9.3

BHV > 19.00

HIV-1 > 13.1 > 9.4

BVDV > 9.4 > 10.3

VSV > 10.9

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Factor IX concentrates

Company

VirusA B C D E

PRV > 15.5 > 7.3 NA NA

HIV > 11.7 > 12.2

BVDV > 15.5

Examples for Overall HBV Reduction Factor (log10)

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Intravenous Immunoglobulin

Company

Virus

A B C D E

PRV > 17.7 > 22.9*

> 20.8*

> 23.2 > 12.2 > 9.3*

> 16.7*

HIV > 20.3 > 14.0

BVDV > 16.6 > 16.9

WNV > 13.8 > 9.9

*Overall HBV reduction factor for different formulations

Examples for Overall HBV Reduction Factor (log10)

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AlbuminCompany

Virus

A B C D E

PRV > 12.00*> 14.00*> 14.1*> 12.2*

> 11.4 > 16.3 > 12.9

HIV-1 > 10.5 > 17.8BVDV > 11.2 > 16.3

*Overall HBV reduction factor for different formulations

Examples for Overall HBV Reduction Factor (log10)

Examples: Kinetics of Virus Inactivation

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Inactivation by Caprylic acid in IGIV Inactivation by Dry Heat in F VIII

Inactivation by S/D in F VIII

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References for Kinetics of Virus Inactivation

Dichtelmüller et al. Contribution to safety of immunoglobulin and albumin from virus partitioning and inactivation by cold ethanol fractionation: a data collection from Plasma Protein Therapeutics Association member companies: Transfusion 2011, in press

Dichtelmüller et al. Robustness of solvent/detergent treatment of plasma derivatives: a data collection from Plasma Protein Therapeutics Association member companies. Transfusion 2009, 49:1931-1943

Other Plasma Derived Therapies

Data for these products were not presented but pathogen safety related data can be found on the FDA website or the websites of the manufacurers:

•Factor XIII•Subcutaneous/intramuscular immunoglobulins•Specific immunoglobulins•Antithrombin III•Alpha1-Proteinase Inhibitor•C1 Esterase Inhibitor•Fibrinogen•S/D plasma

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Summary

• HBV is a lipid enveloped virus with a low resistance to physicochemical agents that are commonly used in the manufacturing process of plasma protein therapies

• Current pathogen testing paradigms for source plasma incorporate orthogonal approaches that includes redundant assay methods (NAT, VMT) and test points within the process (donation, production pool)

• The virus removal/inactivation capacity for HBV in today‘s manufacturing process is in the order of 9 log10 or greater

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Conclusions

• Pathogen safety measures introduced by regulatory agencies and PPTA member companies have significantly improved the safety of plasma derived products relative to pathogens causing chronic diseases, such as HBV.

• Since 1988 no transmission of HBV by a plasma derived medicinal product has been reported.

• Regulatory requirements applied to plasma protein therapies are among the most stringent for any medicinal product.

• PPTA member companies have also introduced additional industry standards for donor selection/screening and testing requirements in the manufacturing process.

Today, plasma protein therapies have a excellent safety record with regards to known and emerging pathogens

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Back up slides