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OTHER ITA SITES:
Stimulating The Body�s Defenses To Fight Cancer
Comediennes such as Gilda Radner and Madeline Kahn, Oscar-winning actresses like Loretta Young and Sandy Dennis, singers Laura Nyro and Dinah Shore, actor Pierce Brosnan�s wife Cassandra Harris, actress Jessica Tandy, former Connecticut governor Ella Grasso, and Martin Luther King�s wife Coretta Scott King all died of ovarian cancer. It�s not just celebrities, politicians or movie stars, who are stricken with ovarian cancer. One in every 55 U.S. women is at risk for ovarian cancer. The American Cancer Society estimates about 22,000 new cases of ovarian cancer will be diagnosed. More than 16,000 women will die because the symptoms are often subtle, and her doctor did not recognize the symptoms soon enough. It is the leading cause of death from gynecologic malignancies, and the fifth leading cause of cancer deaths among women.
Less than one-half the women diagnosed with ovarian cancer will live five years. About 10 to 14 percent live beyond five years after their diagnosis. Their choices have been limited, mainly reserved to variations of chemotherapy drugs or a new way to delivery the drug. The general public is often unaware of the side effects ovarian cancer patients suffer during chemotherapy. In mid March, the U.S. Food and Drug Administration criticized the safety profile of Eli Lilly�s Gemzar for ovarian cancer patients, saying the 2.8 months increased survival seen in studies of patients taking the drug wasn�t enough to offset the treatment�s increased toxicity which included anemia, neutropenia (a blood disorder) and thrombocytopenia (reduced platelets in the blood). Presently used first-line treatments for ovarian cancer patients include Cisplatin, with associated side effects such as nerve, kidney and/or ear damage, Carboplatin (side effects: nerve damage in the arms and/or legs, joint pain, and/or thrombocytopenia), Paclitaxel (neurotoxicity), or Melphalan, with side effects which include irreversible bone marrow failure, bone marrow suppression).
The unsolved problem of chemotherapy is the reduction in the �quality of life.� While some life extension has been proven, the patient�s life deteriorates. Many patients struggle with balancing the loss in quality of life with the rigors of the therapy. Researchers are actively pursuing new directions that may some day provide new hope for the ovarian cancer patient. A University of Minnesota research study has suggested the use of thalidomide, which would be used in conjunction with chemotherapy, as a prospective means of increasing the likelihood of remission. Minnesota cancer researcher Dr. Levi Downs explained, �It prevents the tumor from making new blood vessels. Without new blood vessels, the tumor can�t sufficiently feed new cells, so the cancer can�t grow.� His randomized trial was small with only 65 patients (only 28 took thalidomide), and more testing will certainly be required.
New Hope for Ovarian Cancer Patients?
One promising technology that has been developed over the past decade is OvaRex� MAb. It was developed by ViRexx Medical Corp., an Edmonton-based company, which trades on the American Stock Exchange (ticker symbol: REX) and on the Toronto Stock Exchange (ticker symbol: VIR). Now licensed to Unither Pharmaceuticals, a wholly owned subsidiary of United Therapeutics (NASDAQ: UTHR), OvaRex� MAb is currently undergoing two identical Phase III trials at about 64 research centers across the United States. One trial has completed enrollment, according to a mid December news release issued by ViRexx Medical Corp.
We spoke with ViRexx Medical Corp�s Chief Executive Officer, Dr. Tyrrell who was the Dean of the Faculty of Medicine and Dentistry at the University of Alberta and the Director of the Glaxo Heritage Research Institute. �OvaRex� MAb is our lead candidate for the treatment of ovarian cancer, and is an intravenous infusion of a monoclonal antibody,� he said. Monoclonal antibodies are a new breed of biotech drugs that are extremely specific; that is, each antibody binds to only one particular antigen. In the case of OvaRex� MAb, it is a monoclonal antibody that binds specifically to the CA-125 antigen. Dr. Tyrrell added, �The treatment doesn�t take long, and is given every 4 weeks for the first 3 injections, and then once every 3 months until the patient relapses�.
What makes OvaRex� MAb different from other immunotherapeutic treatments is, instead of attacking the body�s cancerous cells directly, the monoclonal antibody targets the cancerous antigen in circulation. Some believe it helps retrain the body�s immune system to fight the ovarian cancer cells. The mechanism that reportedly has made OvaRex� MAb effective is how it alerts the body to recognize and fight the CA-125.
As with many pioneering scientific breakthroughs, serendipity is what lies behind the OvaRex� MAb story. As one technology was being developed, another � the murine monoclonal antibody treatment for ovarian cancer � came about by accident. We talked to its inventor, Dr. Antoine Noujaim, about the biotech drug�s roots. �It came out of the imaging technology,� the Professor Emeritus of the University of Alberta explained. In the early 1980s, biotech companies, such as Immunomedics and Cytomedics were researching tumors and using antibodies to image the tumors so they could be evaluated in a cancer patient�s body. �I worked with Dr. Mike Longenecker and we established a company called Biomira (Toronto: BRA) in 1984,� Dr. Noujaim recalled. �We had a number of targets and then needed to make specific antibodies.� Part of his effort was to target certain cancers, such as prostate, breast and ovarian cancer.
At this point of his recollections, Noujaim got excited, �Through sheer serendipity, we were using murine antibodies, not humanized antibodies. We were using foreign antibodies, a small amount of foreign antibodies.� How in the world did Noujaim know to use murine (mouse) antibodies? �Because that was the easiest way to do the imaging at the time,� he replied. �Before you make a chimeric (something derived from two different animal species) antibody, you start with a murine one. If that one works, you humanize the antibody.� From this research, Noujaim founded a company called AltaRex, which was taken public in 1995. �We raised about $30 million and expanded the program.�
While the company has licensed, under a royalty agreement, the OvaRex� MAb technology to United Therapeutics, through that company�s subsidiary, Unither Pharmaceuticals, ViRexx has retained rights to most member nations of the European Union and certain other countries. Key ones include France, the United Kingdom and the Benelux countries. ViRexx has also established strategic relationships with Domp� Farmaceutici, Medison Pharma, Ltd. and Genesis Pharma S.A. for certain European and Middle-East Countries.
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