Critical Path: Overview of Selected Ongoing CBER Efforts and Future Opportunities

1. Critical Path:Overview of Selected Ongoing CBER Efforts and Future Opportunities Jesse L. Goodman, M.D., M.P.H Director Center for Biologics Evaluation and Research

2. Blood Derivatives Vaccines BloodComponents Allergenic Extracts Whole Blood Gene, Cell, TissueTherapy Blood Devices Tissues Xenotransplantation

3. FDA Critical Path Initiative • Facilitate product development through better tools and latest technologies for safety, efficacy and product manufacturingwww.fda.gov/oc/initiatives/criticalpath/whitepaper • Focus intramural and extramural science as resources permit • Includes identifying areas, especially new technologies, where needed standards, methods, assays, guidance can be helpful • e.g. gene therapy, tissue engineering, stem cells, new vaccine technologies, blood “substitutes”, pathogen inactivation & detection • Assure internal expertise, appropriate partnerships with industry, academic/scientific community and consumers • Identify “roadblocks”, scientific and regulatory, and develop appropriate solutions – e.g. VIG potency assay, rapid bacterial testing methods • Guidance, standards, outreach, creative approaches to product development, safety/efficacy assessment and review, consistent production

4. FDA Critical Path Initiative • Assures internal expertise, appropriate partnerships with industry, academic/scientific community and consumers • Benefits multiple sponsors; communication • Maintains staff “cutting edge” expertise needed for dealing with evolving biotechnologies • Scientific expertise and confidence foster objectivity • Reduces risks of reflexive over- or under-protectiveness • Make regulation more scientific, less “defensive”

5. Recent Public HealthAccomplishments With Critical Path Components • WNV Blood Donor Screening initiated in 8 months • Unprecedented collaboration with provision of samples, standards, methods, guidance • New HIV, Hep C tests • Intensive interactions with sponsors, expertise sharing • TRANSNET Supply Monitoring Pilot • Successful response to SARS, other EID events: including outreach on product development, needed laboratory studies and standards, vaccine strains • Risk Assessment/Guidances re: TSE, CT & blood safety – in house and collaborative expertise and modeling to address intervention strategies

6. Selected Regulatory Activities With Critical Path Contributions • New Technologies • Successful management of SCID/Gene Therapy adverse events • BRMACs re: Development of islet cell transplantation, cellular therapies for cardiac disease • Outreach/international activities in gene therapy/xenotransplantation • Cell Substrate Guidance • Standards and outreach: e.g. adenovirus, plasma derivatives (Factor VIII), thrombin

7. CBER Research Programs • Increasing orientation toward Critical Path issues • ~ 50% time/effort in regulatory review, inspection, lot release, regulatory policy development • ~ 50% time/effort in critical path/product related research • > 120 Biologics Licensing Applications & > 340 Investigational New Drug Applications directly supported by/related to Research Programs • Evaluated at Site Visits by Advisory Committees • Plan to extend evaluation to broad programmatic areas and include identifying unmet needs and opportunities

8. CBER Research Programs II • ~200 publications in FY03 • Collaborations with >120 outside institutions, including collaborative research and formal leveraging arrangements (~35%) • Other Government Agencies (CDC, NIH, NCI, DOD) • Academia, some focused CRADAs with industry

9. Critical Path Research: Recent Examples; Product Safety • Product Safety: 42% of Research Programs • Mechanisms of toxicity • Unexpected pulmonary uptake of adenovirus vectors in animals with chronic liver disease. Gene Ther 2004 11:431-8 • Comparison of effects of two hemoglobin-based O(2) carriers on intestinal integrity and microvascular leakage. Am J Physiol Heart Circ Physiol 2002 283:H1292-301 • Assay development and validation • Single-tube fluorescent product-enhanced reverse transcriptase assay with Ampliwax (STF-PERT) for retrovirus quantitation. J Virol Methods 2003 108:139-42

10. Adeno Vector-associated Lung Diseasein Setting of Pre-existing Liver Disease macrophage adenovirus Lung cell nucleus A 30 μm Adenovirus inside lung macrophages in rat with liver disease

11. Public Health Promise of Blood “Substitutes” • Donor derived blood products carry risks, e.g., infection & allergic responses, currently managed by product testing and donor evaluation • Most blood products have short shelf lives and must be refrigerated/frozen • Donors often in limited supply (especially in critical situations such as war or bioterrorism) • Effective blood “substitutes” could enhance supply and reduce risks associated with donors

13. CBER Collaborative Safety Research on Blood Oxygen Carriers • Early blood “substitutes” associated with toxicities such as hypertension, inflammation, tissue damage • Evaluate strategies to prevent hemoglobin toxicity, providing knowledge and pathway for manufacturing of second generation products • Identified the link between the “oxidative chemistry” of a given hemoglobin and its toxicity • Developed Endothelial Cell-based Model System to promote understanding of blood substitute toxicity and allow more accurate product testing during development

14. Cell Substrates for Biologics Manufacturing: Safety Studies • Adventitious Agents • Stability of the prion protein-encoding (PRNP) gene in HeLa cells. Biologicals 2003 31:83-6 • Early detection of endogenous retroviruses in chemically induced mouse cells. Virus Res 2001 79:39-45 • Porcine Endogenous Retrovirus Infects but Does Not Replicate in Nonhuman Primate Primary Cells and Cell Lines. J Virol 2002 76:11312-11320

15. Critical Path Research: Recent Examples in Product Characterization • Product Characterization 26% • Development of assays, standards and use of novel technology in regulatory setting • PRODUCT IDENTITY:Genetic and phenotypic analysis of reassortants of high growth and low growth strains of influenza B virus. Vaccine 2003 21:3867-3874 • Detection and Genotyping of Human Group A Rotaviruses by Oligonucleotide Microarray Hybridization. J Clin Microbiol 2002 40:2398-2407

16. Product Characterization • Product Identity, cont’d • Molecular Cloning and Characterization of Genes for Shigella sonnei Form I O Polysaccharide: Proposed Biosynthetic Pathway and Stable Expression in a Live Salmonella Vaccine Vector. Infect Immun 2002 70:4414-4423 • Application of NMR, molecular simulation, and hydrodynamics to conformational analysis of trisaccharides. Biopolymers 2003 69:448-60 • Gene Expression in Human Embryonic Stem Cell Lines: Unique Molecular Signature. Blood 2003 Dec 30

18. Characterization of Stem Cells to Assure Safety & Effectiveness • Normal stem cells can form a variety of tissues and cell types, including blood, brain, bone, muscle etc. • Safety concerns exist that include: • Risk of unregulated growth after inoculation (cancer) • Contamination with infectious agents • Characterization of the stem cells is important in regulating their use as a medical therapy • Inoculated in or expanded from one form, change to another state • Need novel technological methods for accurate characterization

19. Quality Assessment of Stem Cells by Gene Expression Profile Microarray CBER scientists have developed a method to identify and characterize 86 common “stemness” genes in 6 stem cell lines CD24 GTCM-1

20. Product Characterization • Purity • Detection and discrimination of orthopoxviruses using microarrays of immobilized oligonucleotides. J Virol Methods 2003 112:67-78 • Endotoxin content of standardized allergen vaccines. J Allergy Clin Immunol 2003 111:777-83 • Characterization and comparison of commercially available German and American cockroach allergen extracts. Clin Exp Allergy 2002 32:721-7

21. Product Characterization • Potency • Development of a novel vaccinia-neutralization assay based on reporter-gene expression. J Infect Dis 2003 188:440-8 • Enabled both smallpox vaccine production and VIG testing by multiple manufacturers • Methods Development • Use of Coefficient of Variation in Assessing Variability of Quantitative Assays. Clin Diagn Lab Immunol 2002 9:1235-1239 • Lot consistency as an equivalence problem. Control Clin Trials 2003 24: 88 Suppl.

22. Critical Path Research:Efficacy • Product Efficacy 20% • Surrogate measures of efficacy • Sensitivity and reproducibility of HCV quantitation in chimpanzee sera using TaqMan real-time PCR assay. J Virol Methods 2002 105:253 • Comparative Immune Response to PE and PE_PGRS Antigens of Mycobacterium tuberculosis. Infect Immun 2001 69:5606-11 • Innate and adaptive immune responses to an intracellular bacterium, Francisella tularensis live vaccine strain. Microbes Infect 2003 5:135-42

23. Efficacy • Surrogate measures of efficacy, cont’d • Correlates of immunity for pneumococcal conjugate vaccines. Vaccine 2003 21:2199-205 • Immunoglobulin G3 from Polyclonal Human Immunodeficiency Virus (HIV) Immune Globulin Is More Potent than Other Subclasses in Neutralizing HIV Type 1. J Virol 2001 75:6558-65 • Animal models • Vaccination with DNA encoding internal proteins of influenza virus does not require CD8(+) cytotoxic T lymphocytes: either CD4(+) or CD8(+) T cells can promote survival and recovery after challenge. Int Immunol 2000 12:91-101 • DNA vaccine expressing conserved influenza virus proteins protective against H5N1 challenge infection in mice Emerg Infect Dis 2002 8: 796-801

24. Efficacy • Statistical and Epidemiological Analysis • Biomarkers and surrogate endpoints in renal transplantation: present status and considerations for clinical trial design. Am J Transplant 2004 Apr;4(4):451-7 • Proper metrics for clinical trials: transformations and other procedures to remove non-normality effects. Stat Med 2003 22:3823-42 • “Other” 7% • Anticipated products, e.g., SARS

25. Examples of Major Critical Path Investment Opportunities • New vaccine delivery systems, rapid use vectors • Develop/make available well characterized cell banks (and related methods to assay for safety/adventitious agents) useful for vaccine and other biologics production – and update guidance for use • Characterization of cell therapies & links to standardized outcomes (e.g. HPSCs) • Methods & validation of pathogen inactivation for blood, plasma, tissues and other products • Multipathogen and rapid detection methodologies for biologics including blood and tissue products • Improving longevity/storage of blood and tissues

26. New Delivery Methods for Vaccines and Gene Therapies • DNA vaccines & vectors: distribution, integration • Safety testing: Tumorigenicity • New vaccine platforms: Plug and play-ability to generalize and predict immunogenicity and safety • Transgenic plant vaccines • Adjuvants & immune stimulants • CpG, lipid nanotech particles, mucosal/transdermal patch delivery, maternal vaccination • Tumor vaccines • Parasite vaccines

27. Characterize Cellular Products and Link to Outcomes • Develop well characterized standard and innovative biomarkers predictive of product toxicity and efficacy (e.g. genomic and proteomic profiles) • In vitro expanded, selected and genetically modified cell lines • Identify meaningful changes in cell specifications or environmental “stress” on cells • Link molecular and immunologic data to standardized and measurable clinical outcomes across similar studies and products • Types and gene expression patterns of stem cells that will predictably and reproducibly perform well as medical therapy

28. Develop and Facilitate Availability of Cell Substrates for Biologics Products • Vaccines, gene therapies, and recombinant proteins increasingly cell derived • Cell based vaccines may offer enhanced flexibility and capacity for urgent production (e.g. influenza) • Increased number diversity of screened, well characterized cell banks needed to be “on the shelf” for biologics manufacture • Capable of needed performance (e.g. diverse virus types) • Tested for relevant transmissible infectious agents • Tested by well characterized and predictive tumorigenicity assays • Can reduce/eliminate use of animal products in biologics manufacture

29. Detection & Inactivation of Emerging Pathogens in Blood, cell/tissue & Vaccine Products • Multipathogen testing • Need to engage new, rapidly adaptable platforms • Nanotechnology and “flow through” assays • Bacterial contamination • TSE rapid screening • Blood and plasma products – methods to inactivate • In process determination of clearance of viruses& prions • New approaches to TSE’s • Nanofiltration to reduce viral contamination • Chemical treatments • Mechanisms for testing and decontamination of human tissues that preserve integrity

30. Better, Longer Lasting Blood, Cellular and Tissue Products • Improved cryopreservation and thawing methods: development and validation (e.g. for RBC stockpiles, other cellular products) • Improved hemopoeitic stem cell production, quality, and preservation • Enhanced platelet preservation and quality • Blood “substitutes” for field/urgent use

31. Improved Methods of Clinical Data Quality and Analysis • Combined clinical trial data analysis • Development of standardized outcomes measures among product classes • Data mining • New statistical approaches, e.g., pediatric dosing • Large, simple trials to obtain key data and reduce costs, pre- and post-marketing • Develop consensus on handling of “missing data”

32. Thanks! • We believe that FDA can help to identify opportunities and develop better tools to improve the safety, efficacy and predictability of product development along the “critical path” to patients • We look forward to continuing engagement with colleagues and stakeholders in academia, industry, and the public both to further identify and target areas for scientific investment • Together we can enhance successful product development that promotes public health CBER: INNOVATIVE TECHNOLOGY ADVANCING PUBLIC HEALTH