Challenges in Vaccine Production and Rapid Scale up to Meet

Transcription

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
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)
From Clone to Commercial®
WHO Global Influenza Preparedness Plan (2005)
VACCINES
¾ Develop a prioritized global research and development agenda for producing innovative and more efficient vaccines.
¾ Explore ways to shorten the time needed for vaccine prototype preparation …by working with pharmaceutical companies, national authorities and research institutes.
¾ Explore ways to increase availability of pandemic vaccines during pandemic alert and pandemic periods.
US Seasonal Influenza Vaccine Manufacturing
¾ 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 ¾ 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
Manufacturing to meet Pandemic Needs
¾ 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
¾ 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
¾ Vaccine may be manufactured “at‐risk”, ie, without sufficient demonstration of efficacy, to meet timelines
Egg Based Vaccine Technology is Too Slow
¾ Current Egg based vaccine production
• Viral seed stocks are adapted from the wild‐type sequence to obtain higher productivity in eggs
¾ 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.
¾ Typically takes 6‐8 months to produce first doses of vaccine
Time Addresses Flu Vaccine Manufacturing
Time May 18th, 2009
Influenza Virus Types
¾ Influenza Type A
• Infects humans, birds, pigs, horses
• Most prevalent, occurs in several Sub‐Types
• Most likely to demonstrate Antigenic Drift Ö Shift
• Major Antigenic Shift may lead to pandemic
¾ InfluenzaType B
• Infects humans, seals
• Less volatile, no sub‐types
• Antigenic drift, slower than Type A
¾ Influenza Type C
• Comparatively rare – not included in standard vaccines
Diagram of Influenza Virus
Hemagglutinin
HA
Neuraminidase
NA
Influenza Strain Nomenclature
A/Brisbane/10/2007(H3N2)
Virus Type
(A or B)
Where
Isolated
Year
Isolated
Sequential
Number
Hemagglutinin
Sub-Type
Neuraminidase
Sub-Type
For A Strains
Likely Current Flu Strain Nomenclature
A/Mexico/2009(H1N1)
Virus Type
(A or B)
Where
Isolated
Year
Isolated
Hemagglutinin
Sub-Type
Neuraminidase
Sub-Type
A Wide Variety of Influenza A Strains Exist
H1N1
H1N2
H2N2
H3N1
H3N2
H3N8
H5N1
H5N2
H5N3
H7N1
H7N2
H7N3
H9N2
H5N8
H5N9
H7N7
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”
Current US Influenza Vaccines
¾ 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)
¾ For 2008/9, US injected flu vaccine contains three strains:
• A/Brisbane/59/2007 (H1N1)
• A/Brisbane/10/2007 (H3N2)
• B/Florida/4/2006
¾ CDC and WHO have stated that the current seasonal vaccine is not protective against A/Mexico/2009 (H1N1)
• New vaccine must be produced quickly
Antigenic Shift Requires New Vaccine
Time May 18th, 2009
‘Traditional’ Influenza Vaccine Production
Recombinant Seed Virus (New Isolate X Well-growing strain)
Prepare
Substrate
Infect &
Incubate
Remove Cells,
Purify Virus
Inoculate
Allantoic Sac
Harvest Allantoic
Fluid, (10-12ml/egg)
Clarify, UltraCentrifuge
Inactivate Virus
CURRENT…
Incubate
Embryonated Eggs
(1,000s needed)
Future…
Scale up cell
culture from
WCB
Infect or
transfect
in
Bioreactor
VERO, MDCK,
PER-C6, Avian,
Sf-9
Treat with formaldehyde,
Sub-unit vaccines are
then solvent-extracted
Centrifuge, TFF,
Chromatography
Propagation of Virus in Mammalian Cell Culture
¾ 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
¾ 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
¾ Production performed in a contained system
• Reduced risk of bacterial contamination
• Controlled and transferable process
Mammalian Cell Lines for Flu Vaccine Production
¾ 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
¾ Vero (African Green Monkey, established cell line)
• Baxter: Celvapan vaccine, approved in Europe, is produced in Vero cells
¾ PER.C6: Highly characterized and fully documented: Biologics Master File at FDA
Avian Cell Culture Technology
¾ 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
¾ ProBiogen: AGE1.CR, a proprietary duck cell line • Favorable glycosylation properties, scalable, serum free
• Free of retrovirus activity, superior titres
Plant based VLP or Antigen Production
¾ 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
¾ iBioPharma, Inc: iBioLaunch™ platform (hydroponically‐grown green plants), working on influenza vaccine
Baculovirus Expression of Influenza Antigens
¾ 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
¾ Novavax (Rockville, MD, USA) has produced virus‐like particles containing HA, NA, and M protein in baculovirus
• Initiated clinical development in mid‐2007
¾ 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
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
FluBlok®: Rapid Production of New Flu Vaccines
¾ Cloning, expression and manufacture of FluBlok® within 2 months
¾ Influenza rHA antigens are produced in insect cells – protein based vaccine with low endotoxin content
¾ rHA protein is highly purified and does not contain egg protein
¾ Adaptation of strains to produce at high levels not required
¾ Manufacturing of FluBlok® does not require biocontainment facilities
¾ Manufacture of rHA does not include formalin inactivation or organic extraction procedures
Baculovirus vs. Cell Culture Options
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
Veterinary
vaccines
Poliovirus
vaccines, rabies
vaccines
Other human
vaccines, MAbs,
gene therapy,
proteins
Established
protein
expression
system
High viral yield
Proven track
record, used for
other human
vaccines
High
susceptibility to
influenza virus
High yield, high
scalability, low
costs
Key
disadvantage
High tumorigenicity
Low influenza
virus yield
Less well
established cell
Immunogenicity
perceived as low
Companies
involved
Novartis Vaccines,
Solvay, GSK
Baxter
Crucell,
Sanofi-Pasteur
Protein Sciences,
Novavax
Origin
Other uses
Key advantage
Source: DataMonitor 2007
Recombinant Methods are Key to Rapid Production
¾ 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
¾ Baculovirus timeline (recombinant or VLP)
• Generation of baculovirus stock with new antigens
• Short production process, readily transferrable
• First product available in 3‐4 months
¾ Plant‐based production timeline
• Generation of recombinant plant virus with antigens
• Production initiated in 1‐2 months
Global Considerations in Pandemic
¾ 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
¾ Resource availability
• Multiple organizations must be prepared to produce the same vaccine with the same efficacy across the world
¾ Regulatory
• Harmonized regulatory process required to insure global supply can be achieved in timely manner
Acknowledgements
¾ BioProcess Technology Consultants
• Alex Kanarek, Ph.D. • Rick Stock, Ph.D.
• Howard Levine, Ph.D.
¾ Protein Sciences Corporation
• Manon Cox, Ph.D.
THANK YOU!
BioProcess Technology Consultants, Inc.
289 Great Road, Suite 303
Acton, MA 01720 USA
1‐978‐266‐9156 (phone)
1‐978‐266‐9152 (fax)
sjones@bioprocessconsultants.com
www.bioprocessconsultants.com