Friday, April 20, 2007

Human Technology Manufacturing Platforms Part IV. The Flu Vaccine.

In the first three installments, we covered a lot of ground. First, we looked at the "pediatric vaccination question"; specifically, those vaccines in the U.S. pediatric immunization series which are manufactured using cell lines derived from aborted babies. In the second installment, we looked at "levels of cooperation", and what the Vatican has to say about the matter. In the third installment, we were introduced to what is, to my mind, the most important and ominous component of this entire topic: the use of cell lines derived from aborted babies as human technology manufacturing platforms; that is, 'platforms' on which any number of drugs and vaccines can be developed. In this part, we will see how the use of human technology manufacturing platforms is expanding rapidly, and will quite soon come to affect us all. First, it will come via the flu vaccines.

"Seasonal flu" is the usual, well, seasonal, flu that people get, usually caused by a strain of Influenza A or Influenza B. It's the one they give the shots for. There's an Influenza C as well, but it's so mild nobody worries about it. Currently there are 2 types of A (H1N1 and H3N2) and 1 type of B which circulate worldwide and cause seasonal flu. "Pandemic flu" is an outbreak which spreads worldwide, and can be a public health disaster. Some Type A strains occur in swine, horses, and other animals; but wild birds can carry any strain, and the avian strains H5 and H7 are particularly virulent. Pandemics are caused only by strains of Influenza A, and some thirty pandemics have been recorded in the past several centuries (every ten to fifty years or so), with three having occurred in the 20th century: the 1918-1919 "Spanish flu", the 1957-1958 "Asian flu" and the 1968-1969 "Hong-Kong flu". There have also been a couple of false alarms: who remembers the "swine flu"? In the 20th century, the 1918 flu was the horrific one, causing more deaths worldwide in a few months than World War I did in four years. The "Asian" and "Hong-Kong" pandemics were far, far milder. There is some evidence to suggest that the 1918-1919 pandemic occurred when an avian flu strain became capable of infecting humans, which brings us to the current "avian flu." The avian Influenza A strain H5N1 first crossed into a human in southern China in1997, with an outbreak in Asian nations in 2003. Currently, about 177 persons have been infected worldwide with H5N1, with 98 fatalities.[1] It has been noted that, given the potential exposure of millions of people in southeast Asia to H5N1, clinical disease in humans remains at this time a rather rare event. The concern among public health officials is that the genes of H5N1 could "mix" - reassort - with a human strain of Influenza A, thus leading to increased infectivity and a pandemic. Please note: the potentiality of H5N1 to reassort and become the etiology of an Influenza A pandemic is just that, a potential. It is, apparently, a very real potential, so it is prudent for governments to be addressing the issue, but it is, nevertheless, a potential. At least one other avian flu strain - H7N1 - seems to exhibit similar potential.

Regarding the vaccines used for the "seasonal flu," all that are in current use are developed using viral strains grown in embryonated hen's eggs. Each year the most likely candidate A strains as well as the B strain are selected, viruses grown in the eggs, and 15 micrograms of viral antigen put in each dose. The process from strain selection to final product takes six to eight months, and, due to the nature of hen's eggs, is time and labour intensive: each egg must be individually inoculated. Currently there are multiple manufacturers for the seasonal flu vaccine. Cell culture techniques are generally acknowledged as superior to using hen's eggs, and please take note that cell cultures using Madin-Darby Canine Kidney (MDCK) or Vero (African green monkey kidney) are approved for human vaccine production, and have the same benefits as those listed for PER.C6: greater production capability, less risk of transmission of avian flu virus (after all, H5N1 is a disease of poultry) and decreased labour requirements.[2] In addition, there are numerous other strategies for developing a vaccine rapidly enough, and in sufficient quantities, to confront a pandemic. This is crucial to keep in mind as we move through the discussion which follows: PER.C6 or some other human cell line is not a requirement to address the threat of an influenza pandemic with H5, or any other strain. There are other ways. The U.S. Department of Health and Human Services plans to phase out use of the egg-based vaccine, and replace it with the cell culture- based vaccine[3]. It further appears to be the case that this would be true for both the "seasonal" flu vaccine, as well as a "pandemic flu vaccine stockpile." The reasons are those noted previously: increased flexibility, less cumbersome manufacture, and higher antigenicity. The question is, will it be a cell line derived from animals, or from aborted babies?

Sanofi-Pasteur is the vaccine division of the French conglomerate Sanofi-Aventis Group, based in Lyons, France. The U.S. corporate headquarters are in Swiftwater, PA. In May, 2004, the National Institute of Allergy and Infectious Disease (NIAID, a branch of the National Institutes of Health, which in turn is under the auspices of the U.S. Department of Health and Human Services) awarded Sanofi a contract to develop 8000 doses of investigational H5N1 vaccines. These were presumably egg-based doses. In November, 2004, HHS announced that it had awarded Sanofi another $10 million to develop egg production facilities to ensure a continuous supply of eggs in the event of a pandemic or vaccine shortage.[4] This represented the third agreement between HHS and Sanofi to develop a pandemic influenza vaccine response; this third agreement, in addition to the up front $10 million, had options giving a total potential value of $41 million.[5] So far, so good; this all appears to be appropriate groundwork for egg based H5N1 vaccines in the event of a pandemic. However, on 1 April 2005, Sanofi Aventis Group announced that it had been awarded a $97 million contract by the United States Health and Human Services Department "...to speed production process for new cell culture influenza vaccines in the US..."[6] The contract is to both develop the PER.C6 vaccine, and design and develop a new U.S. PER.C6 cell culture manufacturing facility to be located in Swiftwater, PA. The same press release repeated the two main advantages of human cell culture over the usual conventional influenza viral culture medium of chicken eggs already cited in the literature: (1) the cell culture technique decreases the start up time for a new viral culture from four weeks to three, and (2) it eliminates the need for all those eggs. In September, 2005, Sanofi was awarded another $150 million to manufacture vaccine in bulk form at the Swiftwater location. Although unspecified in the press release, this is presumably the egg based vaccine.[7] Finally, at the same time as the initial May, 2004 contract, another vaccine manufacturer, Chiron (Emeryville, CA and Marburg, Germany) was also awarded a contract by DHHS for production and clinical testing of an H5N1 vaccine.[8] Now, this is important: the Chiron investigational vaccine is based on a cell line, the Madin Darby Canine Kidney (MDCK) cell line mentioned above. The Chiron vaccine is in U.S. Phase I/II study, and has completed a second Phase III European study.[9] So, like Sanofi, Chiron is rapidly developing a cell culture based vaccine. But, Chiron is using an animal line, MDCK. Sanofi is using PER.C6. Sanfoni-Pasteur's avian influenza (H5N1) is lagging behind the Chiron MDCK vaccine; Sanofi's will enter clinical trials in Norway in the Spring of 2006.[10] Perhaps the extra boost from U.S. DHHS dollars will help them out.

Another biotechnology company, Vaxin, based in Birmingham, Alabama, announced a license agreement with Crucell on 13 September, 2004, to use the PER.C6 cell line to develop vaccines against influenza, anthrax, respiratory syncytial virus (RSV), and other unspecified diseases.[11] The influenza vaccine is especially interesting; unlike the Sanofi product discussed above, the Vaxin product is to be an inhaled flu vaccine developed on the PER.C6 line.[12] The vaccine is already in Phase I clinical trials, and full FDA approval is anticipated in 2009. To date, Vaxin has been awarded $10 million in Federal funds to develop this product.[13]

In addition to the influenza vaccines, I offer a short and far from complete miscellany of companies and vaccines here. The Aeras Global TB Vaccine Foundation of Bethesda, Maryland, contracted with Crucell $2.9 million to develop a new tuberculosis vaccine using PER.C6 to replace the old BCG TB vaccine (not used in the United States).[14]

The PER.C6 cell line is being used in the development of Merck's HIV-1 vaccine; this licensing agreement was actually the first for the cell line between Crucell and a major vaccine manufacturer, in 2001.[15] The research moved into Phase I clinical trials in 2002,[16] and it was recently announced that the candidate vaccines will move into "the next phase of clinical trials in the near future."[17]
Crucell and the Walter Reed Army Institute of Research have signed an agreement to evaluate PER.C6 for the development of vaccines against Japanese encephalitis, dengue fever, and West Nile fever viruses.[18]

At this point, a pause for a brief summary is in order. Currently, the following human cell lines derived from aborted babies are in use: WI-38, MRC-5, and PER.C2. The following vaccines use them: rubella (WI-38, as well as the viral strain originally grown out of RA27/3), varicella (WI-38, MRC-5), hepatitis A (MRC-5), rabies (MRC-5), and polio (MRC-5). Rabies and polio have alternative vaccines currently available. Rubella once had alternatives; in fact prior to the introduction of Merck’s WI-38/RA 27/3 based vaccine, there were no fewer than three rubella vaccines licensed and in use in the U.S. market. One was based on a duck embryo cell culture, one on a dog kidney culture, and one on a rabbit kidney culture.[19] They were withdrawn from the U.S. market after the introduction of MERUVAX, although at least two remain licensed by the FDA and could be “brought back on the market tomorrow.”[20] Vaccines utilizing human cell cultures which are currently under development, or entering clinical trials include smallpox (MRC-5), influenza A (PER.C6), influenza B (PER.C6), "avian flu" vaccines (PER.C6), tuberculosis (PER.C6), respiratory syncytial virus (PER.C6), HIV-1 (PER.C6), anthrax (PER.C6) and various encephalopathic viruses (PER.C6). This list is not inclusive, and discusses only vaccines.

As is appropriate for a versatile manufacturing platform, in 2002 the PER.C6 line was "launched (into) commercial production of fully human monoclonal antibodies,"[21] something totally divorced from vaccine production. This "launch" consisted of a formal collaboration between Crucell and the Dutch biotechnology company DSM Biologics, which develops biopharmaceutical products. The biopharmaceutical product market segment is currently EURO 30 billion and is growing about 20% annually;[22] in 15 to 20 years it is projected to reach USD $200 billion. "PER.C6 has the potential to become the technology of choice for an attractive part of that market."[23] "Biopharmaceuticals" is roughly synonymous with another biotech buzzword, "monoclonal antibody (Mab) therapeutics." Mab's are becoming increasingly used in cancer therapies, as they are antibodies directed at specific antigens found on the malignant cells. They attach to the antigens, and activate compliment-mediated and cell-mediated cytotoxicity, resulting in death or arrest of the malignant cells.[24] They are, in effect, "magic bullets" targeted at specific malignant cells, and thus have high specificity with minimal side effect profiles. Currently there are over a dozen monoclonal antibody therapies in clinical use, against certain forms of breast cancer and certain stomach cancers, certain leukemias, and certain lymphomas. I have observed the effects of a couple of these therapies; they are, truly, remarkable. In addition, there is what has been described as a "bulging pipeline" of new Mab's against an even broader array of cancers as well as chronic autoimmune inflammatory diseases with high morbidity such as rheumatoid arthritis and ulcerative colitis. As far as I can tell, none of the existing Mab's were developed using human cell lines, but Crucell as well as numerous other biotech companies are aggressively pursuing Mab development using human lines such as PER.C6.[25] Interestingly, it is not just anticancer therapies where Mab's have potentialities; they may prove useful in infectious diseases as well. Research is underway looking at Mab therapies for severe acute respiratory syndrome (SARS, caused by a coronavirus)[26] and rabies,[27] among others. All of the Mab therapies are amenable to development on human cell lines, though human cell lines such as PER.C6 are not required. Animal lines such as Vero or MDCK work as well (and are generally the ones which are used in the research papers). Finally, PER.C6 is being actively developed as a platform for various gene therapies. Like Mab's, this is a field which will be simply exploding in the very near future.

Next week: What happens now?

Endnotes.
[1] This synopsis on the flu developed from www.answers.com and the on-line encyclopedia Wikipedia, www.wikipedia.com. In addition, the Kamps et. al. Influenza Report 2006 is an outstanding reference, available as a free PDF download at www.influenzareport.com
[2] Influenza Report 2006 Chapter 6, "Vaccines," see section entitled "Vaccines and technology and development." The author of the chapter, Dr. Korsman, does not list PER.C6 in his chapter, but only the animal cell lines.
[3] Fauci, A. "Race against time." Nature Vol. 435:423-424, 26 May 2005.
[4] "Secretary Thompson Announces Contract To Secure Future Egg Supply For Flu Vaccines." HHS Press Office, 9 Nov 2004, www.dhhs.gov/news/press/2004pres/20041109a.html
[5] "Aventis and U.S. Department of Health and Human Services Enter into Third Pandemic Influenza Vaccine Agreement." Aventis Press Release, 9 November 2004, Sanofi-Aventis
[6] "Sanfoni pasteur awarded $97 million HHS contract to accelerate cell-culture pandemic influenza vaccine development." Sanfoni Aventis "Press Room" Year 2005, www.en.sanfoni-aventis.com
[7] "Sanofi Pasteur Delivers More H5N1 Vaccine For U.S. Government Pandemic Initiatives." Sanofi-Aventis Press Release, 6 February 2006 See also the press release of 15 September 2005.
[8] "Questions and Answers, H5N1 Avian Flu Vaccine Trials, Question 3.: What vaccines are being tested?" National Institute of Allergy and Infectious Diseases, National Institutes of Health March 2006, at www3.niaid.nih.gov/news/newsreleases/2005/H5N1QandA.htm
[9] "Chiron Initiates U.S. Phase I/II Study of Influenza Cell Culture Vaccine." Chiron News, 25 October 2005
[10] "High-volume avian influenza vaccine a step closer." in-PharmaTechnologist.com, 14 October 2005.
[11] "Crucell and Vaxin Announce PER.C6 Licensing Agreement." 13 Sep 2004, Birmingham. www.vaxin.com
[12] "Revolutionary Flu Vaccine in Development by Vaxin, Inc.: Vaxin Technology Utilizes Cell Culture for Manufacturing." Press release, 11 October 2004, www.vaxin.com
[13] "Federal funding is key to vaccine producer Vaxin." Birmingham Business Journal, Vol. 21, No. 43, 22 Oct 2004
[14] "Aeras partners with Crucell to develop TB vaccine." Press Release, 24 March 2004, Leiden, The Netherlands. www.aeras.org News and Events.
[15] United Business Media, op cit.
[16] "Crucell: preliminary Phase I data of PER.C6-derived HIV vaccine encouraging." Press release, Bionews,/Medicine/Immunotechnology 05 March 2002, Biotechnology Investment Today, Ltd. www.investinbiotech.com/pressroom
[17] "PER.C6-produced HIV vaccine to advance to next phase of clinical trials." NewsRx, "AIDS Weekly" section, 20 September 2004, www.newsrx.com/newsletters/AIDS-Weekly
[18] "Crucell and WRAIR sign CRADA to evaluate PER.C6(R) Technology for Development of Flavivirus Vaccines." Market Wire News, 22 December 2005, www.marketwire.com
[19] Maxcy-Rosenau-Last Public Health, pg. 95.
[20] Aborted Fetal Cell Lines, footnotes 24 & 25.
[21] ibid, Crucell, "Corporate History"
[22] "Biotech Alliance of DSM Biologics & Crucell - for faster preparation of new medicines at lower cost." Biotech Industry General Issues press release, 19 December 2002, www.investinbiotech.com
[23] Quote from Leendert Staal, president of DSM, found in "Crucell/DSM push PER.C6 technology forward." in-Pharmatechnoligist.com on line pharmaceutical news, 23 December 2005, www.in-pharmatechnologist.com/news
[24] Fishelson, Z. "Obstacles to cancer immunotherapy: expression of membrane complement regulatory proteins (mCRPs) in tumors." Molecular Immunology 40(2-4):109-123, Sep. 2003.
[25] "First milestone achieved in Centocor-Crucell Agreement for CD46 human antibodies against cancer." Medicine/Biotherapeutics 1 February 2002, www.investinbiotech.com/pressroom
[26] ter Meulen, J. et al. "Human monoclonal antibody as prophylaxis for SARS coronavirus infection in ferrets." Lancet 363(9427):2139-41, 26 Jun 2004. See also van den Brink, E. et al. "Molecular and Biological Characterization of Human Monoclonal Antibodies Binding to the Spike and Nucleocapsid Proteins os Severe Acute Respiratory Syndrome Coronavirus>" Journal of Virology 79(3):1635-1644, Feb. 2005.
[27] Goudsmit, J. et al. "Comparison of an anti-rabies human monoclonal antibody combination with human polyclonal anti-rabies immune globulin." Journal of Infectious Diseases 193(6):796-801, 15 Mar 2006.

1 comment:

Aaron said...

Wow, a lot of information here. Really fascinating stuff. I hope it works out.