Tanox was a
biopharmaceutical
A biopharmaceutical, also known as a biological medical product, or biologic, is any pharmaceutical drug product manufactured in, extracted from, or semisynthesized from biological sources. Different from totally synthesized pharmaceuticals, t ...
company based in
Houston, Texas. The company was founded by two biomedical research scientists,
Nancy T. Chang and
Tse Wen Chang in March 1986 with $250,000, which was a large part of their family savings at that time. Both Changs grew up and received college education in chemistry in
National Tsing Hua University
National Tsing Hua University (NTHU; ) is a public research university in Hsinchu City, Taiwan.
National Tsing Hua University was first founded in Beijing. After the Chinese Civil War, the then-president of the university, Mei Yiqi, and othe ...
in Taiwan and obtained Ph.D. degrees from
Harvard University
Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of high ...
. For postdoctoral training, Tse Wen shifted to immunology and did research with
Herman N. Eisen at the Center for Cancer Research,
M.I.T.
The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the m ...
The two Changs successively became research managers and worked with a range of
monoclonal antibody
A monoclonal antibody (mAb, more rarely called moAb) is an antibody produced from a cell Lineage made by cloning a unique white blood cell. All subsequent antibodies derived this way trace back to a unique parent cell.
Monoclonal antibodies ...
projects in
Centocor, Inc. based in
Malvern, Pennsylvania
Malvern is a borough in Chester County, Pennsylvania. It is west of Philadelphia. The population was 3,419 at the 2020 census. The borough is bordered by Paoli Pike on the south, Sugartown Road on the west, Willistown Township on the east, an ...
, from 1981 to 1985.
The Changs were recruited by
Baylor College of Medicine
Baylor College of Medicine (BCM) is a medical school and research center in Houston, Texas, within the Texas Medical Center, the world's largest medical center. BCM is composed of four academic components: the School of Medicine, the Graduate S ...
toward the end of 1985 and offered faculty positions in the Division of Molecular Virology. Soon after their arrival, they were encouraged by a high-ranking Baylor official and local business leaders to start a biotech venture in Houston. This was in a period of time when the economy of Houston was in slump as the result of the collapse of the oil industry.
The Changs rented a corner of about 2000 square feet in a large empty warehouse building on Stella Link Road, located four miles away from the
Texas Medical Center
The Texas Medical Center (TMC) is a medical district and neighborhood in south-central Houston, Texas, United States, immediately south of the Museum District and west of Texas State Highway 288. Over 60 medical institutions, largely concentrat ...
, and built laboratories. In 1987, Tanox obtained a $4 million cash infusion from the legendary biotech venture capitalist and investor, Moshe Alafi,
who was a founding investor of
Cetus
Cetus () is a constellation, sometimes called 'the whale' in English. The Cetus was a sea monster in Greek mythology which both Perseus and Heracles needed to slay. Cetus is in the region of the sky that contains other water-related constellat ...
,
Amgen
Amgen Inc. (formerly Applied Molecular Genetics Inc.) is an American multinational biopharmaceutical company headquartered in Thousand Oaks, California. One of the world's largest independent biotechnology companies, Amgen was established in T ...
,
Biogen
Biogen Inc. is an American multinational biotechnology company based in Cambridge, Massachusetts, specializing in the discovery, development, and delivery of therapies for the treatment of neurological diseases to patients worldwide.
History
...
, and a few other successful biotech companies. Nancy was the Chairman, President, and CEO of Tanox in its 21-year history, while Tse Wen was responsible for creating most of the company's proprietary technology and patents. Tanox's major technology was based on a series of inventions and a family of dominant patents, most notably those relating to the "anti-IgE therapy",
[The family of anti-IgE patents. http://www.google.com/patents/US5422258; http://www.google.com/patents/US5428133; http://www.google.com/patents/US5449760; http://www.google.com/patents/US5543144; http://www.google.com/patents/US5614611.] the "migis concept",
[The family of patents relating to the "migis" concept. http://www.google.com/patents/US5091313; http://www.google.com/patents/US5252467; http://www.google.com/patents/US5260416; http://www.google.com/patents/US5292867.] and the "anti-CεmX approach",
[The family of patents relating to the "anti-CεmX approach". http://www.google.com/patents/US5254671; http://www.google.com/patents/US5274075; http://www.google.com/patents/US5342924.] that pertained to the use of
humanized antibodies for targeting
immunoglobulin E
Immunoglobulin E (IgE) is a type of antibody (or immunoglobulin (Ig) " isotype") that has been found only in mammals. IgE is synthesised by plasma cells. Monomers of IgE consist of two heavy chains (ε chain) and two light chains, with the ...
(IgE) and IgE-expressing
B lymphocyte
B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted or ...
s for the treatment of allergic diseases.
Tanox was able to recruit many talented scientists, bioengineers, and other professionals, many of whom from the Texas Medical Center. Tanox held an
initial public offering
An initial public offering (IPO) or stock launch is a public offering in which shares of a company are sold to institutional investors and usually also to retail (individual) investors. An IPO is typically underwritten by one or more investme ...
and was listed in the
NASDAQ in 2000. It eventually occupied the entire warehouse building and established additional R & D facilities in the adjacent land for carrying out various therapeutic antibody programs.
Many researchers grew to be top-level research managers in pharmaceutical and large biotech companies.
Tanox became the first major acquisition of
Genentech in an all-cash buyout deal (US$919 million)
[Genentech Announces Agreement to Acquire Tanox for $20 Per Share. ''Genentech News'' November 9, 2006. http://www.gene.com/media/press-releases/10167/2006-11-09/genentech-announces-agreement-to-acquire] in August 2007 (Genentech itself became wholly owned by
Roche
F. Hoffmann-La Roche AG, commonly known as Roche, is a Swiss multinational healthcare company that operates worldwide under two divisions: Pharmaceuticals and Diagnostics. Its holding company, Roche Holding AG, has shares listed on the SIX ...
in March 2009). The acquisition of Tanox has boosted Roche/Genentech's product pipeline substantially.
[Roche Investor Day 2012.
http://www.roche.com/investors/ir_agenda/ir_day-2012.htm.
] In addition to the enhancement of the anti-IgE franchise by the increased rights on
Xolair
Omalizumab, sold under the brand name Xolair, is a medication used to treat asthma, nasal polyps, and urticaria (hives).
Omalizumab is a recombinant DNA-derived humanized IgG1k monoclonal antibody that specifically binds to free human immunoglo ...
(
omalizumab
Omalizumab, sold under the brand name Xolair, is a medication used to treat asthma, nasal polyps, and urticaria (hives).
Omalizumab is a recombinant DNA-derived humanized IgG1k monoclonal antibody that specifically binds to free human immunoglo ...
) and by the potential utility of
TNX-901
Talizumab (TNX-901) is a humanized monoclonal antibody that was under development by Tanox in Houston, Texas as a new-concept therapeutic for allergic diseases. The unique anti-IgE antibody was designed to target immunoglobulin E ( IgE) and IgE-ex ...
(
Talizumab), the other pipeline products that have gained considerable prominence include
TNX-355 (
Ibalizumab
Ibalizumab, sold under the brand name Trogarzo, is a non-immunosuppressive humanised monoclonal antibody that binds CD4, the primary receptor for HIV, and inhibits HIV from entering cells. It is a post-attachment inhibitor, blocking HIV from bin ...
), a unique anti-CD4 antibody for treating
AIDS,
TNX-650 (
Lebrikizumab
Lebrikizumab ( INN) is a humanized monoclonal antibody and an experimental immunosuppressive drug for the treatment of asthma that cannot be adequately controlled with inhalable glucocorticoids. The drug was created by Tanox under the name ''TNX ...
), an anti-
interleukin-13 antibody for treating asthma, and TNX-224, an Fab fragment of a humanized antibody against Factor D of the human immune
complement system to be tested for treating geographic atrophy associated with dry age-related macular degeneration.
Based on Tanox's invention of the “anti-CεmX (also referred to anti-M1’) approach”, Genentech is developing
Quilizumab
Quilizumab (INN) is a humanized monoclonal antibody designed for the treatment of asthma
Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow o ...
, an antibody specifically targeting mIgE on B cells, for asthma and allergic diseases.
The anti-IgE program
Tanox started the "anti-IgE therapy" program and developed a prototype antibody candidate in 1987, and subsequently converted the mouse antibody candidate into a chimeric form and obtained crucial set of data on the antibody in 1988–89. The Tanox' anti-IgE antibodies were designed to target free IgE in blood and IgE-expressing B lymphocytes for the purpose of intercepting the IgE-mediated pathway, without binding to IgE already bound by the
high affinity IgE receptors on
mast cells
A mast cell (also known as a mastocyte or a labrocyte) is a resident cell of connective tissue that contains many granules rich in histamine and heparin. Specifically, it is a type of granulocyte derived from the myeloid stem cell that is a ...
and
basophils
Basophils are a type of white blood cell. Basophils are the least common type of granulocyte, representing about 0.5% to 1% of circulating white blood cells. However, they are the largest type of granulocyte. They are responsible for inflammator ...
or bound by the low-affinity IgE receptors on many cell types. An ordinary anti-IgE antibody, if were injected into a patient, would cause a massive activation of mast cells and basophils and hence
anaphylactic
Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the follo ...
shocks.
By 1989, Tanox had collected data showing that their proposed therapeutic lead anti-IgE antibody could not induce the activation of basophils isolated from the blood of any of many extremely allergic individuals, even under the most permissive conditions.
In order to secure funding to develop the anti-IgE program, the Changs were busily engaged throughout 1989 in trying to find a corporate partner among about 25 pharmaceutical and biotech companies, who were willing to meet with them, to co-develop the anti-IgE therapeutic program.
In 1990, Tanox signed a corporate partnership with
Ciba-Geigy
Novartis AG is a Swiss-American multinational pharmaceutical corporation based in Basel, Switzerland and
Cambridge, Massachusetts, United States (global research).name="novartis.com">https://www.novartis.com/research-development/research-loca ...
(Ciba-Geigy merged with
Sandoz
Novartis AG is a Swiss-American multinational pharmaceutical corporation based in Basel, Switzerland and
Cambridge, Massachusetts, United States (global research).name="novartis.com">https://www.novartis.com/research-development/research-loca ...
to form
Novartis
Novartis AG is a Swiss-American multinational pharmaceutical corporation based in Basel, Switzerland and
Cambridge, Massachusetts, United States (global research).name="novartis.com">https://www.novartis.com/research-development/research-loc ...
in 1996) to jointly develop the anti-IgE program. The companies named the antibody candidate CGP51901 (CGP short for "Ciba-Geigy Product"), which humanized form was later created and named
TNX-901
Talizumab (TNX-901) is a humanized monoclonal antibody that was under development by Tanox in Houston, Texas as a new-concept therapeutic for allergic diseases. The unique anti-IgE antibody was designed to target immunoglobulin E ( IgE) and IgE-ex ...
or
talizumab. With the funding from Ciba-Geigy, Tanox established a 500-liter cGMP
bioreactor
A bioreactor refers to any manufactured device or system that supports a biologically active environment. In one case, a bioreactor is a vessel in which a chemical process is carried out which involves organisms or biochemically active substances ...
plant in a space adjacent to the research laboratories in the warehouse building and produced CGP51901 for phase I and II clinical trials.
The joint team from Tanox and Ciba-Geigy received "
investigational new drug" (IND) application approval, which is required for the first testing of a new substance in human subjects, for an anti-IgE antibody for the first time, from the U.S.
Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...
(FDA) in 1991. This was an important milestone in the development history of the anti-IgE program; Tanox scientists had anticipated major difficulty to receive IND approval for an anti-IgE antibody from the FDA, even though they had experimental data to show that CGP51901 would act differently from an ordinary anti-IgE antibody. Subsequently, Tanox/Ciba Geigy carried out a dose-escalating, double-blinded, placebo-controlled single-dose phase I clinical trial on 33 pollen-sensitive subjects with elevated serum IgE levels in
Southampton, England
Southampton () is a port city in the ceremonial county of Hampshire in southern England. It is located approximately south-west of London and west of Portsmouth. The city forms part of the South Hampshire built-up area, which also covers Por ...
.
After resolving a few unexpected clinical findings, mainly the accumulating IgE and anti-IgE immune complexes, from the phase I trial, Ciba-Geigy and Tanox ran a successful phase II trial in 153 patients with severe seasonal
allergic rhinitis
Allergic rhinitis, of which the seasonal type is called hay fever, is a type of inflammation in the nose that occurs when the immune system overreacts to allergens in the air. Signs and symptoms include a runny or stuffy nose, sneezing, red, i ...
toward mountain cedar pollens in three medical centers in Texas in 1994–1995.
The positive clinical trial results, which showed increasing efficacy of CGP51901 over three different dosages (15, 30, or 60 mg in six bi-weekly doses) in improving nasal and ocular symptom scores, impressed the researchers and clinical investigators working on a similar anti-IgE program in Genentech.
In 1996, after a 3-year long lawsuit between Tanox and Genentech was settled out-of-court, Genentech made its first payment of $16 million to Tanox, and Tanox, Novartis, and Genentech formed a tripartite partnership to develop the anti-IgE program.
A humanized anti-IgE antibody from Genentech,
omalizumab
Omalizumab, sold under the brand name Xolair, is a medication used to treat asthma, nasal polyps, and urticaria (hives).
Omalizumab is a recombinant DNA-derived humanized IgG1k monoclonal antibody that specifically binds to free human immunoglo ...
, with identical key binding characteristics as CGP51901, was chosen by a joint program steering committee for further development, because it had a better developed manufacturing process.
Omalizumab, with the trade name
Xolair
Omalizumab, sold under the brand name Xolair, is a medication used to treat asthma, nasal polyps, and urticaria (hives).
Omalizumab is a recombinant DNA-derived humanized IgG1k monoclonal antibody that specifically binds to free human immunoglo ...
, was approved by the U.S. Food and Drug Administration in 2003 for use in patients 12 years and older with moderate-to-severe allergic
asthma
Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, co ...
. It was subsequently approved in the
European Union
The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been de ...
and many other countries for patients 12 years and older with severe, persistent allergic asthma.
Antibody therapeutics
Among the
humanized antibody drugs Tanox developed by itself or with corporate partners:
*
Omalizumab
Omalizumab, sold under the brand name Xolair, is a medication used to treat asthma, nasal polyps, and urticaria (hives).
Omalizumab is a recombinant DNA-derived humanized IgG1k monoclonal antibody that specifically binds to free human immunoglo ...
, trade name
Xolair
Omalizumab, sold under the brand name Xolair, is a medication used to treat asthma, nasal polyps, and urticaria (hives).
Omalizumab is a recombinant DNA-derived humanized IgG1k monoclonal antibody that specifically binds to free human immunoglo ...
*
TNX-901
Talizumab (TNX-901) is a humanized monoclonal antibody that was under development by Tanox in Houston, Texas as a new-concept therapeutic for allergic diseases. The unique anti-IgE antibody was designed to target immunoglobulin E ( IgE) and IgE-ex ...
, also referred to as
talizumab. Two leading allergy researchers, Donald Leung and Hugh Sampson, led a team of clinical investigators and performed a double-blinded, randomized, dose-ranging, multi-center trial of TNX-901 in 84 patients with a history of immediate hypersensitivity to peanut and found that a 450-mg dose of TNX-901 significantly and substantially increased the threshold of sensitivity to peanut on oral food challenge from a level equal to approximately half a peanut (178 mg) to one equal to almost nine peanuts (2805 mg). The team concluded that this result is very significant, because it represents an effect that should translate into protection against most unintended ingestions of peanuts.
The study has been widely regarded as an important milestone in the search for an effective treatment for the often frightening peanut allergy that affects many families with young children with extreme sensitivity to peanut.
* The "anti-CεmX (or anti-M1’) approach". In 1990, Tse Wen Chang invented the “migis concept” for developing therapeutic approaches that target membrane-bound
immunoglobulin (mIg), which is part of the
B-cell receptor
The B cell receptor (BCR) is a transmembrane protein on the surface of a B cell. A B cell receptor is composed of a membrane-bound immunoglobulin molecule and a signal transduction moiety. The former forms a type 1 transmembrane receptor protein, ...
(BCR) on B cells, in an isotype-specific fashion.
This migis approach ("migis" is an acronym for "mIg isotype-specific") was supported by the subsequent findings that the extracellular peptide segments, which are referred to as “migis peptides”, of the transmembrane anchor peptides at the C-termini of the five isotypes of heavy chains of the five classes of mIg's vary from 13 to 32 amino acid residues in length and are each unique and substantially different among the five isotypes in amino acid sequences. In the process of characterizing the gene segment and mRNA encoding the C-terminal peptide of human membrane-bound ε chain (mε), Tanox's scientists unexpectedly discovered that an isoform of mε exists as the predominant isoform, arising from a previously unknown alternative splicing of the mε RNA transcript. This “long” isoform of mε contains a discrete domain of 52 amino acid residues located between the CH4 domain and the migis peptide segment of mε.
The domain was referred as “CεmX” to denote that it is part of the constant region of the membrane-bound ε chain of unknown function. The first patent applications with claims covering CεmX sequence and antibodies against CεmX were filed in 1990, and the discovery of CεmX was presented by Tanox's scientists in the annual meeting of the
American Association of Immunologists
The American Association of Immunologists (AAI) is an international scientific society dedicated to furthering the study of immunology. AAI provides its members with a variety of platforms in which to exchange ideas and present the latest immunolo ...
in April 1991. Several other groups were able to repeat the findings and to confirm the amino acid sequence of CεmX as disclosed by the Tanox group. Terms, such as “M1’ (M1 prime)” and “me.1”, were also used by other groups to refer to the CεmX domain. Not much further research on the CεmX domain had been done until Chang's team at the
National Tsing Hua University
National Tsing Hua University (NTHU; ) is a public research university in Hsinchu City, Taiwan.
National Tsing Hua University was first founded in Beijing. After the Chinese Civil War, the then-president of the university, Mei Yiqi, and othe ...
in Taiwan made the first
monoclonal antibodies against CεmX in 2001.
Since Genentech acquired Tanox in 2007, the anti-M1’ program has been carried out in a fast pace
and favorable results have been obtained from two Phase I and one Phase IIa clinical trials on a humanized antibody, 47H4 (also referred to as MEMP1972A, or
quilizumab
Quilizumab (INN) is a humanized monoclonal antibody designed for the treatment of asthma
Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow o ...
). These clinical trial results have shown that the anti-M1’ antibody is safe and can block the synthesis of allergen-specific IgE and associated allergic response upon the challenge of the allergens. Quilizumab is now being studied in a Phase IIb trial.
*
TNX-355, also referred to as TMB-355 or
Ibalizumab
Ibalizumab, sold under the brand name Trogarzo, is a non-immunosuppressive humanised monoclonal antibody that binds CD4, the primary receptor for HIV, and inhibits HIV from entering cells. It is a post-attachment inhibitor, blocking HIV from bin ...
, a humanized monoclonal antibody that binds to the cell surface molecule,
CD4, the receptor for the
AIDS-causing
human immunodeficiency virus
The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immun ...
(
HIV
The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune ...
). TNX-355 inhibits HIV entry into host target cells without interfering with T cell function. The antibody, which was licensed from
Biogen
Biogen Inc. is an American multinational biotechnology company based in Cambridge, Massachusetts, specializing in the discovery, development, and delivery of therapies for the treatment of neurological diseases to patients worldwide.
History
...
in 1997, is a new-concept drug and the first in its class.
After Tanox was acquired by Genentech in 2007, the TNX-355 technology and its development right were licensed to a Taiwanese company, TaiMed Biologics. TNX-355 is now in expanded phase II trials in many countries.
*
TNX-650, also referred to as "MILR1444A" or"
Lebrikizumab
Lebrikizumab ( INN) is a humanized monoclonal antibody and an experimental immunosuppressive drug for the treatment of asthma that cannot be adequately controlled with inhalable glucocorticoids. The drug was created by Tanox under the name ''TNX ...
", a humanized antibody that blocks
interleukin 13
Interleukin 13 (IL-13) is a protein that in humans is encoded by the ''IL13'' gene. IL-13 was first cloned in 1993 and is located on chromosome 5q31 with a length of 1.4kb. It has a mass of 13 kDa and folds into 4 alpha helical bundles. The second ...
(IL-13). When Genentech acquired Tanox in 2007, a satisfactory Phase I trial had been performed. Subsequently, Genentech accomplished several Phase II trials on patients with asthma.
Lebrikizumab is now in two Phase III trials on patients with asthma uncontrolled with corticosteroids and an additional medication.
* TNX-224, an anti-Factor D Fab, the antigen-binding fragment of a humanized monoclonal antibody targeting Factor D of the human complement system. The product candidate is also referred to as "FCFD4514S" or "RG7417". The drug is designed to inhibit complement activation and chronic inflammation in tissues. Complement Factor D is a member of the trypsin family of peptidases and is a component of the alternative complement pathway. When Genentech acquired Tanox in 2007, Tanox scientists had already demonstrated the efficacy of the candidate drug in blocking complement and leukocyte activation in baboon model of cardiopulmonary bypass. Genentech is evaluating anti-Factor D for geographic atrophy associated with dry age-related macular degeneration in a Phase II clinical trial.
Other major technologies
Other than the therapeutic antibodies, which target the IgE allergic pathway, immune factors, and CD4, Tanox also possessed several other major patented technologies. Among those, two sets of patents represent landmark inventions in their respectively related fields. Largely because these patents were awarded too far ahead the maturation of the peripheral technologies, they did not bring material financial impact on Tanox. Nonetheless, the creation of these technologies helped germinate the two important fields and enhanced Tanox as a pioneer in the antibody field.
* “
Antibody matrix
An antibody microarray (also known as antibody array) is a specific form of protein microarray. In this technology, a collection of captured antibodies are spotted and fixed on a solid surface such as glass, plastic, membrane, or silicon chip, and ...
” methodology and applications,
which focused on
antibody microarray
An antibody microarray (also known as antibody array) is a specific form of protein microarray. In this technology, a collection of captured antibodies are spotted and fixed on a solid surface such as glass, plastic, membrane, or silicon chip, and ...
s and laid out the
microarray concept generally. While working in Centocor, Tse Wen Chang invented this technology in 1983. When the Changs were setting up Tanox in 1986, they bought the rights on these antibody matrix patents from Centocor to help formulate their first business plan. Tanox made efforts to develop “immunosorbent cytometry” methodology
to determine the immunocyte profile, such as the concentrations and proportions of
CD3+,
CD4+, and
CD8
CD8 (cluster of differentiation 8) is a transmembrane glycoprotein that serves as a co-receptor for the T-cell receptor (TCR). Along with the TCR, the CD8 co-receptor plays a role in T cell signaling and aiding with cytotoxic T cell-antigen int ...
+ T cells in blood, for monitoring the immune status of individuals infected with the
AIDS virus,
human immunodeficiency virus
The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immun ...
(
HIV
The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune ...
), which was causing expanding epidemic in the 1980s and 1990s. However, the anti-IgE program and other therapeutic antibody programs eventually absorbed all resources Tanox had, and the antibody matrix program was not pursued further.
* The concept and methodology of “selecting low-frequency antigen-specific single
B lymphocyte
B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted or ...
s for performing
PCR for making antibodies”,
[Patents relating to making monoclonal antibodies by performing PCR on single antigen-specific B cells to obtain VH and VL. http://www.google.com/patents/US5213960; http://www.google.com/patents/US5256542; http://www.google.com/patents/US5326696.] which was invented by Tse Wen Chang in 1992. The set of patents pertain to the generation of monoclonal antibodies, especially human monoclonal antibodies, by identifying and sorting out low-frequency B lymphocytes, which express antibodies specific for certain desired antigens, and then performing
polymerase chain reaction
The polymerase chain reaction (PCR) is a method widely used to rapidly make millions to billions of copies (complete or partial) of a specific DNA sample, allowing scientists to take a very small sample of DNA and amplify it (or a part of it) ...
on those single B cells to obtain V
H and V
L sequences. In the past few years, an increasing number of research groups in academia and industry have employed similar methodologies to generate human monoclonal antibodies.
References
External links
www.tanox.com
{{Pharmaceutical companies of the United States
Genentech
Defunct pharmaceutical companies of the United States
Companies based in Houston
1986 establishments in Texas
2007 disestablishments in Texas
Pharmaceutical companies established in 1986
Pharmaceutical companies disestablished in 2007
Defunct companies based in Texas