BIOVEST INTERNATIONAL INC (BVTI) - Description of business
We also have developed an automated cell culture instrument, called AutovaxID, to reduce the manpower and production space requirements and costs associated with the production of our BiovaxID vaccine. We believe that this instrument will facilitate our commercial production of BiovaxID following approval. Further, we have formed a wholly-owned subsidiary, AutovaxID, Inc., and have leased space in St. Louis, Missouri to conduct the business which will commercially market this automated instrument.
We also manufacture instruments and disposables used in the hollow fiber production of cell culture products. Our hollow fiber cell culture products and instruments are used by biopharmaceutical and biotech companies, medical schools, universities, research facilities, hospitals and public and private laboratories. We also produce mammalian and insect cells, monoclonal antibodies, recombinant and secreted proteins and other cell culture products using our unique capability, expertise and proprietary advancements in the cell production process known as hollow fiber perfusion.
Our business consists of three primary business segments: development of our therapeutic anti-cancer vaccine, BiovaxID for follicular NHL; assembly and sale of instruments and consumables; and commercial production of cell culture products and services.
BiovaxID is an injectable patient-specific vaccine that we are developing to treat the follicular form of non-Hodgkin's lymphoma. BiovaxID is a customized immunotherapy that is derived from a patient's own cancer cells and is designed to utilize the power of each patient's immune system to recognize and destroy cancerous lymphoma cells while sparing normal cells. BiovaxID is currently undergoing a pivotal Phase 3 clinical trial with patients diagnosed with the indolent follicular form of B-cell NHL.
The Human Immune System
The immune system is the body's natural defense mechanism for recognizing and combating viruses, bacteria, cancer cells, and other disease-causing organisms. The primary disease fighting function of the immune system is carried out by white blood cells. In response to the presence of disease, white blood cells can mediate two types of immune responses, referred to as innate immunity and adaptive immunity. Innate immunity refers to a broad, first line of immune defense that occurs as a part of an individual's natural biological makeup. Adaptive immunity, on the other hand, is specifically generated by a person's immune system throughout the person's lifetime as he or she is exposed to particular pathogens, which are agents such as bacteria or other microorganisms that cause disease. In contrast to the broad but unspecific response of innate immunity, the adaptive immune response generates a highly specific, long-lasting, and powerful protection from repeated infection by the same pathogen. This adaptive immune response facilitates the use of preventative vaccines that protect against viral and bacterial infections such as measles, polio, diphtheria and tetanus.
Adaptive immunity is mediated by a subset of white blood cells called lymphocytes, which are divided into two types: B-cells and T-cells. In the bloodstream, B-cells and T-cells recognize molecules known as antigens, which are proteins or other substances that are capable of triggering a response in the immune system. Antigens include toxins, bacteria, foreign blood cells, and the cells of transplanted organs. When a B-cell recognizes a specific antigen, it secretes proteins, known as antibodies, which in turn bind to a target containing that antigen and tag it for destruction by other white blood cells. When a T-cell recognizes an antigen, it either promotes the activation of other white blood cells or initiates destruction of the target cells directly. A person's B-cells and T-cells can collectively recognize a wide variety of antigens, but each individual B-cell or T-cell will recognize only one specific antigen. Consequently, in each person's bloodstream, only a relatively few lymphocytes will recognize the same antigen.
In the case of cancer, cancer cells produce molecules known as tumor-associated antigens, which may or may not be present in normal cells but may be over-produced in cancer cells. T-cells and B-cells have receptors on their surfaces that enable them to recognize the tumor associated antigens. While cancer cells may naturally trigger a T-cell-based immune response during the initial appearance of the disease, the immune system response may not be sufficiently robust to eradicate the cancer. The human body has developed numerous immune suppression mechanisms to prevent the immune system from destroying the body's normal tissues, and because all cancer cells are originally normal tissue cells, they are often able to aberrantly exploit these mechanisms to suppress the body's immune response, which would normally destroy them. Even with an activated immune system, the number and size of tumors can overwhelm the immune system.
In the case of cancer and other diseases, immunotherapies are designed to utilize a person's immune system in an attempt to combat the disease. There are two forms of immunotherapy used to treat diseases: passive and active. Passive immunotherapy is exemplified by the intravenous infusion into a patient of antibodies specific to the particular antigen, and while passive immunotherapies have shown clinical benefits in some cancers, they require repeated infusions and can cause the destruction of normal cells in addition to cancer cells. An active immunotherapy, on the other hand, generates an adaptive immune response by introducing an antigen into a patient, often in combination with other components that can enhance an immune response to the antigen. Although active immunotherapeutics have been successful in preventing many infectious diseases, their ability to combat cancers of various types has been limited by a variety of factors, including the inability of tumor antigens to elicit an effective immune response, difficulty in identifying suitable target tumor antigens, inability to manufacture tumor antigens in sufficiently pure form, and inability to manufacture sufficient quantities of tumor antigens. Nevertheless, there are many active immunotherapeutics for cancer in the late stages of clinical trials, and some are demonstrating encouraging results.
There are two features of B-cell follicular NHL that make it a particularly attractive form of cancer for treatment with an active immunotherapeutic approach. First, the malignant B-cell lymphocytes in follicular NHL have a unique, identifiable tumor-specific antigen domain that is expressed on the surface of each and every cancerous B-cell in a particular patient and not expressed on any other cells. This is in contrast to other solid cancer tumors, such as prostate, pancreatic, or lung carcinomas, which have a heterogeneous expression of different kinds of antigens on their cell surfaces and for which identification and inclusion of all tumor-specific antigens is very challenging. Second, in cases of relapse after conventional treatment, the malignant B-cells in follicular NHL represent the original cancerous clone. Consequently, the cancer cells that survive treatment of NHL seem to always represent tumor cells with the same antigen idiotype as the original tumor. An idiotype consists of the characteristics of an antigen that make it unique. In follicular NHL patients, the idiotype antigen protein expressed on the tumor cell's surface is not functioning as an antigen because of its failure to elicit a sufficient immune response to the presence of the tumor cells, and the goal of our BiovaxID active immunotherapy is to trigger the body's immune system to recognize such protein as an antigen by introducing a purified version of the idiotype antigen, modified by conjugation to a foreign carrier protein, into the patient's system in conjunction with an immune system stimulant, as described more specifically below.
NHL is a cancer of the lymphatic system, which is a part of the immune system and serves as the body's primary blood filtering and disease fighting tissue. In NHL, specific cells in the lymphatic system become abnormal and multiply in an uncontrolled manner, outliving their normal programmed lifespan, and spreading through the body. NHL can occur in both B-cells and T-cells.
NHL is the sixth most common cancer and the sixth leading cause of death among cancers in the U.S. Approximately 85% of diagnosed cases of NHL are in the form of B-cell NHL, while 15% are T-cell NHL. There are approximately 55,000 new cases of NHL diagnosed each year in the U.S. with a comparable number estimated in Europe, and an estimated 12,500 of the U.S. cases each year are a type of B-cell NHL known as indolent follicular NHL. Our IND and Phase 3 clinical trial for BiovaxID are for indolent follicular NHL.
NHL is usually classified for clinical purposes as being either "indolent" or "aggressive," depending on how quickly the cancer cells are likely to grow and spread. The indolent, or slow-growing, form of NHL has a very slow growth rate and may need little or no treatment for months or possibly years. Aggressive, or fast-growing, NHL tends to grow and spread quickly and cause severe symptoms. Indolent and aggressive NHL each constitute approximately half of all newly diagnosed B-cell NHL, and roughly half of the indolent B-cell NHL is follicular NHL. Follicular NHL is a form of NHL that is derived from a type of cell known as a follicle center cell. Despite the slow progression of indolent B-cell NHL, the disease is almost invariably fatal. According to the American Cancer Society, the median survival time from diagnosis for patients with indolent B-cell NHL having stage III or IV follicular B-cell NHL is between seven and ten years. Unlike indolent B-cell NHL, approximately 30-60% of aggressive B-cell NHL cases are cured by standard chemotherapy.
Chemotherapy is widely used as a first line of treatment for NHL. Although chemotherapy can substantially reduce the tumor mass and in most cases achieve a clinical remission, the remissions are generally short-lived. Indolent B-cell NHL patients generally relapse within a few months or years of initial treatment, and the cancer usually becomes increasingly resistant to further chemotherapy treatments. Eventually, the patient's response to therapy is so brief and weak that further chemotherapy would offer no clinical benefit.
A number of passive immunotherapies, such as Rituxan, Bexxar, and other monoclonal antibodies, are approved by the FDA for the treatment of indolent B-cell follicular lymphoma. These therapies have been used as primary treatment and also as part of combination treatment including chemotherapy. A monoclonal antibody is a type of antibody produced in large quantity that is specific to an antigen that is expressed by tumor cells but may also be expressed by at least some normal cells. These NHL antibody therapies target an antigen that all B cell lymphocytes, both normal and cancerous, have on their surface. As such, the effects of therapy include a temporary reduction in normal B-cell lymphocytes, which can predispose patients to the risk of infection. Generally, these therapies alone have failed to provide unlimited remissions for most patients, and their cost and side-effects are often significant. Moreover, as passively administered antibodies, they do not elicit a sustained immune response to tumor cells. Nevertheless, some recent studies suggest that sustained remissions might be possible with the use of these passive immunotherapies at or near the time of initial diagnosis, either alone or in combination with chemotherapy, and we do not believe that the use of passive and active immunotherapeutics are necessarily mutually exclusive. Rituxan is used in approximately 85% of all new cases of NHL per year, and U.S. sales of Rituxan exceeded $1.5 billion in 2004.
Development of Patient-Specific Vaccine for NHL
During the late 1980s, physicians at Stanford University began development of an active immunotherapy for the treatment of indolent B-cell NHL, and the work was thereafter continued by Dr. Larry Kwak and his colleagues at the NCI. In 1996, the NCI began a Phase 2 clinical trial and selected us to produce the vaccine for the trial. In 2001, we entered into a cooperative research and development agreement, or CRADA, with the NCI under which we jointly conducted the Phase 3 clinical trial. The NCI filed the Investigational New Drug application, or IND, for BiovaxID in 1994, and in April 2004, sponsorship of the IND was formally transferred from the NCI to us.
Studies have shown that treatment with an active immunotherapy should allow a patient's own immune system to produce both B-cells and T-cells that recognize numerous portions of the tumor antigen and generate clinically significant immune responses. These studies have been published in the October 22, 1992 issue of The New England Journal of Medicine, the May 1, 1997 issue of Blood, and the October 1999 issue of Nature Medicine. With respect to follicular NHL and other cancers, tumor cells remaining in the patient after completion of surgery, radiation, and chemotherapy are the cause of tumor relapse. These residual tumor cells cannot be detected by imaging, but their destruction may be feasible by active immunotherapy. With a patient-specific active vaccine, patients receive their own tumor idiotype, as the vaccine is customized for the tumor target of the individual patient. Repeated vaccination with such a tumor vaccine provides the patient's immune system with an additional opportunity to be effectively activated by the tumor cell itself.
Our research has focused on the indolent form of follicular NHL, which accounts for about 90% of newly diagnosed cases of follicular NHL. In about 40-70% of the indolent cases, there is transformation of the indolent form to a more aggressive lymphoma, such as large-cell follicular NHL. This transformation is typically an early event in the course of the disease, usually occurring before the sixth year after diagnosis, and it is mainly observed in patients with known adverse prognostic factors. It is the goal of BiovaxID to intervene in the transformation process by treating newly diagnosed patients in their first clinical remission with the hope of inducing indefinitely prolonged remission and thereby eliminating the possibility of transformation to a more aggressive form of the disease.
BiovaxID Treatment and Production Process
BiovaxID is designed to utilize the power of each patient's immune system and cause it to recognize and destroy cancerous lymphoma B-cells while sparing normal B-cells. Typically, all of a patient's cancerous B-cells are replicate clones of a single malignant B-cell, and, accordingly, all of a patient's cancerous B-cells express the same surface antigen idiotype which is absent from non-cancerous cells. BiovaxID is designed to use the patient's own antigen idiotype from the patient's tumor cells to direct the patient's immune system to mount a targeted immune response against the tumor cells. In general, the therapy seeks to accomplish this result through the extraction of tumor cells from the patient, the culturing and growing of a cell culture that secretes idiotype proteins found in the patient's tumor cells, the production and enhancement of a purified version of the cancer idiotype antigen, and the injection of the resulting vaccine into the patient. By introducing a highly-concentrated purified version of the cancer antigen into the patient's system, the vaccine is designed to trigger the immune system to mount a more robust response to the specific antigen, in contrast to the comparatively weak and insufficient pre-vaccination response. Because the antigen is specific to the cancerous B-cells and not found on normal B-cells, the immune response should target the cancerous B-cells for destruction and not cause harm to the normal cells.
The BiovaxID production and treatment process begins when a sample of the patient's tumor is extracted by a biopsy performed by the treating physician at the time of diagnosis, and the sample is shipped refrigerated to our manufacturing facility in Worcester, Massachusetts. At our manufacturing facility, we identify the antigen idiotype that is expressed on the surface of the patient's tumor cells through laboratory analysis. The patient's tumor cells are then fused with an exclusively licensed laboratory cell line from Stanford University to create a hybridoma. A hybridoma is a hybrid cell resulting from the fusion of a patient tumor cell and a murine/human heterohybridoma myeloma cell, which is an antibody-secreting cell created from a fused mouse and human cell. The purpose of creating a hybridoma is to create a cell that secretes antibody proteins bearing the same idiotype or antigen as the patient's tumor cells. The hybridoma cell can be used to produce the vaccine because the tumor-specific antigen expressed on the surface of the patient's tumor cells is itself an antibody.
After the creation of the hybridoma, we determine which hybridoma cells display the same antigen idiotype as the patient's tumor cells, and those cells are selected to produce the vaccine. The selected hybridoma cells are then seeded into our hollow fiber bioreactors, where they are cultured and where they secrete an antibody bearing the same idiotype antigen as the patient's tumor cells. The secreted antigens are then collected from the cells growing on the hollow fibers. After a sufficient amount of antigen is collected for the production of an appropriate amount of the vaccine, the patient's antigen idiotype is purified using an affinity chromatography column. Affinity chromatography is a technique used to separate and purify a biological molecule from a mixture by passing the mixture through a column containing a substance to which the biological molecule binds.
The resulting purified idiotype antigen is then conjugated, or joined together, with keyhole limpet hemocyanin, or KLH, to create the vaccine. KLH is a foreign carrier protein that is used to improve the immunogenicity, or ability to evoke an immune response, of the tumor-specific antigen. The vaccine is then frozen and shipped to the treating physician. At the treating physician's office, the vaccine is thawed and injected into the patient as an antigen.
We expect that the initial vaccination will typically commence six months after the patient enters clinical remission following chemotherapy. The vaccine is administered in conjunction with GM-CSF, a natural immune system growth factor that is administered with an antigen to stimulate the immune system and increase the response to the antigen. The patient is administered five monthly injections of the vaccine in the amount of .5 milligram of vaccine per injection, with the injections being given over a six-month period of time in which the fifth month is skipped. Through this process, the patient-specific antigens are used to stimulate the patient's immune system into targeting and destroying B-cells bearing the same antigen idiotype.
To our knowledge, BiovaxID is the only NHL vaccine currently in development under an IND that is produced through a hybridoma process. The hybridoma process is different from the recombinant processes being used by other companies that are currently developing an active idiotype immunotherapeutic for NHL. In the recombinant process, the patient's own tumor cells are not fused with lymphocytes, but instead the vaccine is produced by introducing genetic material bearing certain portions (known as the variable light and variable heavy chains) of the tumor-derived idiotype protein into mammalian or insect cells. In contrast, hybridoma method will produce high-fidelity copies of the antigen that, through clonal reproduction, exactly replicates the original gene sequences of the tumor specific idiotype of the parent tumor cell, the recombinant method gives rise to protein products that have combinations of gene sequences different from those of the patient's tumor. We use a method known as "hollow-fiber perfusion" to produce the cell cultures used in the manufacture of BiovaxID. Hollow-fiber perfusion, as compared to other cell culture methods, seeks to grow cells to higher densities more closely approaching the density of cells naturally occurring in body tissue. The hollow-fiber perfusion method involves using hair-like plastic fibers with hollow centers which are intended to simulate human capillaries. Thousands of these fibers are inserted in a cartridge, which we refer to as a bioreactor. The cells are grown on the outside of the hollow fibers while nutrient media used to support cell growth is delivered through the hollow centers of the fibers. The fiber walls have small pores, allowing nutrients to pass from the hollow center to the cells. The fibers act as filters and yield concentrated secreted products. Because the cells are immobilized in the bioreactor, the concentrated product can be harvested during the ongoing cell growth process. We believe that hollow-fiber technology permits the harvests of cell culture products with generally higher purities than stirred-tank fermentation, a common alternative cell culture method, thereby reducing the cost of purification as compared to stirred tank fermentation. Additionally, the technology associated with the hollow-fiber process generally minimizes the amount of costly nutrient media required for cell growth as opposed to other cell culturing techniques.
We believe that our vaccine's anti-tumor effect could exceed that of non-targeted traditional therapy, such as chemotherapy, as our therapy arises from the immune system's defense cells' innate ability to selectively target tumor antigen while not attacking the normal healthy B-cells. The immune response triggered by our vaccine against the cancerous tissue is a natural disease-fighting mechanism without causing the side-effects associated with chemotherapy and radiation used to traditionally treat NHL. We also believe that our vaccine's effectiveness could exceed that of passive immunotherapies, such as Rituxan, Bexar, and other monoclonal antibodies. Unlike BiovaxID, these therapies do not target the unique antigen idiotype that is found on the surface of the patient's tumor cells. Instead, they target an antigen that is common to all B-cells, known as the CD-20 antigen, which results in the undesirable destruction of normal B-cells.
Manufacture of BiovaxID
For our Phase 3 clinical trials, we manufactured BiovaxID at our manufacturing facility in Worcester, Massachusetts, operated by Biovax, Inc., our wholly owned subsidiary. If we receive FDA approval of the vaccine, we may continue to manufacture the vaccine at our existing facility in Worcester, although we will likely need to develop additional facilities or utilize third-party contract manufacturers to fully support commercial production for the U.S. markets. To penetrate markets outside of the U.S., we may enter into agreements such as collaborations with well-established companies that have the capabilities to produce the product, licenses, joint ventures or other arrangements to produce and/or market the product in such countries. To facilitate commercial production of the vaccine, we are developing proprietary manufacturing equipment, for which we have filed "AutovaxID" as a trademark. AutovaxID integrates and automates various stages of vaccine production. We believe that the AutovaxID system will reduce the space and staff currently required for production of the vaccine. In May 2006, we were informed by the FDA that AutovaxID requires no further review by the FDA, allowing us to commence commercialization of the device. On August 7, 2006, we formed a new wholly-owned subsidiary corporation called AutovaxID, Inc., to conduct business of assembling and commercially distributing our AutovaxID instruments from its leased facility in St. Louis, Missouri.
Because we use KLH in the BiovaxID manufacturing process, we have entered into a supply agreement with BioSyn Arzneimittel GmbH, or BioSyn, to supply us with KLH. Under this agreement, BioSyn is obligated to use commercially reasonable efforts to fulfill all of our orders of KLH, subject to certain annual minimum orders by us. However, BioSyn does not have a specific obligation to supply us with the amounts of KLH currently being supplied and necessary for our current clinical trial purposes or for commercialization. The supply agreement specifies a purchase price for the KLH and also provides for a one-time licensing fee payable by us in installments. In light of the regulatory strategy to pursue conditional approval, which has resulted in the current data lock implemented in our Phase 3 clinical trial and the resulting temporary freeze on the enrollment or treatment of new patients, we have entered into an agreement with BioSyn to suspend our minimum order requirements and the minimum royalty payments called for in the supply agreement. The agreement expires in December 2007 but will automatically renew for unlimited successive terms of five years each unless we provide notice of termination to BioSyn at least 6 months before the expiration of any term. No such termination notice has been provided. The agreement can be terminated prior to expiration by either party upon the winding-up or receivership of the other party or upon a default that remains uncured for 60 days. Also, the agreement can be terminated by BioSyn if we cease to develop BiovaxID.