Challenges in Vaccine Production and Rapid Scale up to Meet Emerging Pandemic Threats

Transcription

1 Challenges in Vaccine Production and Rapid Scale up to Meet Emerging Pandemic Threats Susan Dana Jones, Ph.D. BioProcess Technology Consultants, Inc. BIO 2009 Process Zone Theater Atlanta, GE May 20, 2009

2 WHO Statement on Influenza Pandemic The objective of pandemic planning is to enable countries to be better prepared to recognize and manage an influenza pandemic. Planning may help to reduce transmission of the pandemic virus, to decrease cases, hospitalizations and deaths, to maintain essential services and to reduce the economic and social impact of an influenza pandemic. * *From WHO Checklist for Influenza Preparedness Planning (2005)

3 WHO Global Influenza Preparedness Plan (2005) VACCINES Develop a prioritized global research and development agenda for producing innovative and more efficient vaccines. Explore ways to shorten the time needed for vaccine prototype preparation by working with pharmaceutical companies, national authorities and research institutes. Explore ways to increase availability of pandemic vaccines during pandemic alert and pandemic periods.

4 US Seasonal Influenza Vaccine Manufacturing Flu vaccines are generally manufactured by propagation of attenuated viruses in their natural host, chicken eggs Over 95% of US flu vaccine is manufactured in eggs Feasible because host range of human flu includes birds Patients with egg allergies are not able to use egg produced product For seasonal flu,~50 million vaccine doses are produced annually WHO identifies the likely seasonal strains in early spring based on epidemiology and virology studies in Asia Manufacturing and distribution requires 6 8 months from identification of the likely infectious strains

5 Manufacturing to meet Pandemic Needs In a pandemic or emerging pandemic such as the current A/H1N1, an effective vaccine is not immediately available Virus can be isolated and sequenced rapidly Millions of doses must be produced and distributed quickly Manufacturing approach, process, and scale up strategy must be in place and ready to implement for new virus Requires rapid and scalable methods Previous regulatory approval for the methods useful to meet tight timelines Vaccine may be manufactured at risk, ie, without sufficient demonstration of efficacy, to meet timelines

6 Egg Based Vaccine Technology is Too Slow Current Egg based vaccine production Viral seed stocks are adapted from the wild type sequence to obtain higher productivity in eggs Procurement and quality control of vast quantity of eggs Need to increase the flock size to increase egg output which takes several months Flocks are maintained under controlled conditions (time consuming to replicate for larger flocks) The specially certified eggs for the annual flu vaccine have to be ordered with a lead time of up to one year. Typically takes 6 8 months to produce first doses of vaccine

7 Time Addresses Flu Vaccine Manufacturing Time May 18 th, 2009

8 Influenza Virus Types Influenza Type A Infects humans, birds, pigs, horses Most prevalent, occurs in several Sub Types Most likely to demonstrate Antigenic Drift Shift Major Antigenic Shift may lead to pandemic InfluenzaType B Infects humans, seals Less volatile, no sub types Antigenic drift, slower than Type A Influenza Type C Comparatively rare not included in standard vaccines

9 Diagram of Influenza Virus Hemagglutinin HA Neuraminidase NA

10 Influenza Strain Nomenclature A/Brisbane/10/2007(H3N2) Virus Type (A or B) Where Isolated Year Isolated Hemagglutinin Sub-Type Neuraminidase Sub-Type Sequential Number For A Strains

11 Likely Current Flu Strain Nomenclature A/Mexico/2009(H1N1) Virus Type (A or B) Where Isolated Year Isolated Hemagglutinin Sub-Type Neuraminidase Sub-Type

12 A Wide Variety of Influenza A Strains Exist H1N1 H1N2 H2N2 H3N1 H3N2 H3N8 H5N1 H5N2 H5N3 H5N8 H5N9 H7N1 H7N2 H7N3 H7N7 H9N2 H9N7 H1N1 is the type of the current Flu pre pandemic strain H1N1 was the 1918 Spanish Flu type: 20% world population died H2N2 caused the 1957 Asian Flu H3N2 caused the 1968 Hong Kong Flu H5N1 is the type associated with Avian Flu

13 Current US Influenza Vaccines Three types of products currently licensed in US are all produced in eggs Solvent extracted HA and NA antigens (injected) Inactivated whole virus (injected) Live, attenuated virus (FluMist, delivered by inhalation) For 2008/9, US injected flu vaccine contains three strains: A/Brisbane/59/2007 (H1N1) A/Brisbane/10/2007 (H3N2) B/Florida/4/2006 CDC and WHO have stated that the current seasonal vaccine is not protective against A/Mexico/2009 (H1N1) New vaccine must be produced quickly

14 Antigenic Shift Requires New Vaccine Time May 18 th, 2009

15 Traditional Influenza Vaccine Production Recombinant Seed Virus (New Isolate X Well-growing strain) Prepare Substrate Infect & Incubate Remove Cells, Purify Virus Inactivate Virus CURRENT Incubate Embryonated Eggs (1,000s needed) Inoculate Allantoic Sac Harvest Allantoic Fluid, (10-12ml/egg) Clarify, Ultra- Centrifuge Treat with formaldehyde, Future Scale up cell culture from WCB Infect or transfect in Bioreactor Centrifuge, TFF, Chromatography Sub-unit vaccines are then solvent-extracted VERO, MDCK, PER-C6, Avian, Sf-9

16 Propagation of Virus in Mammalian Cell Culture Speed, flexibility, independent of chicken eggs Half the time of traditional methods Manufacturing does not require weakened forms of the virus, resulting in vaccine availability after approximately 12 weeks Can be used to produce virus that would kill chicken egg Product can be used in patients with egg allergy In days to weeks, the required cell amount can be produced Biopharmaceutical industry advances in cell culture applicable to production of vaccines in mammalian cells Production performed in a contained system Reduced risk of bacterial contamination Controlled and transferable process

17 Mammalian Cell Lines for Flu Vaccine Production MDCK (canine kidney, very established cell line) Optimized for the production of flu vaccine and tested with numerous virus variants Novartis Optaflu product, approved in Europe, is manufactured using whole virus propagation in MDCK cells Vero (African Green Monkey, established cell line) Baxter: Celvapan vaccine, approved in Europe, is produced in Vero cells PER.C6: Highly characterized and fully documented: Biologics Master File at FDA

18 Avian Cell Culture Technology Vivalis: EB66 non genetically modified duck embryonic stem cells Genetic stability, Diploid karyotype No adventitious agents (ALV, avian viruses), No RT activity High cell densities as suspension cells Indefinite cell proliferation Animal serum free culture conditions ProBiogen: AGE1.CR, a proprietary duck cell line Favorable glycosylation properties, scalable, serum free Free of retrovirus activity, superior titres

19 Plant based VLP or Antigen Production Medicago s Proficia VLP Vaccine Technology Uses a transient system which expresses recombinant vaccine antigens in plants (Nicotiana benthamiana) Requires the genetic sequence of the virus, limiting delays that may happen with traditional systems Antigen to the influenza A (H1N1) strain was expressed within 14 days of receiving the DNA sequence Could deliver a vaccine for testing in about a month after the identification and reception of genetic sequences ibiopharma, Inc: ibiolaunch platform (hydroponically grown green plants), working on influenza vaccine

20 Baculovirus Expression of Influenza Antigens Influenza antigens can be expressed by cloning into Baculoviruses and growing in insect cell culture No replication in or infection of mammalian cells Rapid scale up and production of new vaccine strains possible Novavax (Rockville, MD, USA) has produced virus like particles containing HA, NA, and M protein in baculovirus Initiated clinical development in mid 2007 Protein Sciences (Meriden, CT, USA) has developed FluBlok using their proprietary baculovirus expression system Contains three recombinantly produced HA antigens Over 50,000 doses delivered with minimal adverse events Filed BLA in April 2008

21 Protein Sciences FluBlok Expression Baculovirus Expression Vector System (BEVS) Engineer baculovirus with the gene of interest (e.g. Hemagglutinin) Baculoviruses highly specific to insect cells Powerful promoter generates high yield of protein of interest Culture expression of insect cells in a fermenter Infect cells with engineered virus Incubate infection for ~48-72 hours Protein forms rosettes Purify protein to > 90% into final product Formulate with PBS into vaccine

22 FluBlok : Rapid Production of New Flu Vaccines Cloning, expression and manufacture of FluBlok within 2 months Influenza rha antigens are produced in insect cells protein based vaccine with low endotoxin content rha protein is highly purified and does not contain egg protein Adaptation of strains to produce at high levels not required Manufacturing of FluBlok does not require biocontainment facilities Manufacture of rha does not include formalin inactivation or organic extraction procedures

23 Baculovirus vs. Cell Culture Options Origin MDCK Vero Per.C6 Sf9 Madin Darby Canine Kidney African green monkey kidney Human embryonic retina Spodoptera frugiperda Relative yield High Low Moderate Very high Tumorigenicity High Not demonstrated Weak None Other uses Veterinary vaccines Poliovirus vaccines, rabies vaccines Key advantage High viral yield Proven track record, used for other human vaccines Key disadvantage Companies involved High tumorigenicity Novartis Vaccines, Solvay, GSK Low influenza virus yield Baxter Other human vaccines, MAbs, gene therapy, proteins High susceptibility to influenza virus Less well established cell Crucell, Sanofi-Pasteur Established protein expression system High yield, high scalability, low costs Immunogenicity perceived as low Protein Sciences, Novavax Source: DataMonitor 2007

24 Recombinant Methods are Key to Rapid Production Cell culture timeline (virus propagation) Identification of new virus sufficient to begin production Rapid growth of required cell biomass and virus replication Product available quickly Baculovirus timeline (recombinant or VLP) Generation of baculovirus stock with new antigens Short production process, readily transferrable First product available in 3 4 months Plant based production timeline Generation of recombinant plant virus with antigens Production initiated in 1 2 months

25 Global Considerations in Pandemic Technology Cell based technologies for flu vaccines are scalable; well established for biopharmaceuticals Baculovirus can be designed to produce flu antigens or VLP rapidly, based on sequence data Plant based systems can rapidly deliver doses of new vaccine Resource availability Multiple organizations must be prepared to produce the same vaccine with the same efficacy across the world Regulatory Harmonized regulatory process required to insure global supply can be achieved in timely manner

26 Acknowledgements BioProcess Technology Consultants Alex Kanarek, Ph.D. Rick Stock, Ph.D. Howard Levine, Ph.D. Protein Sciences Corporation Manon Cox, Ph.D.

27 THANK YOU! BioProcess Technology Consultants, Inc. 289 Great Road, Suite 303 Acton, MA USA (phone) (fax) sjones@bioprocessconsultants.com