Scientists studying brain-wasting diseases linked to mad cow have warned that a new class of cancer drugs have the potential to set off similar brain deterioration.
The new cancer-treatment compounds, known as proteasome inhibitors, block cell machinery used to digest unwanted proteins. But the researchers, led by Susan Lindquist, a professor at the Massachusetts Institute of Technology, said using such compounds in mice helped produce brain-wasting symptoms.
Drugs in the class include Velcade, which is being tested in patients by Millennium Pharmaceuticals, Cambridge, Mass., and the National Cancer Institute. David Schenkein, vice president for clinical oncology at Millennium Pharmaceuticals, said the findings weren't viewed as cause for concern because the drug isn't able to cross into the brain.
Millennium's is the only proteasome-inhibitor cancer drug to enter human tests, said John Wright, a senior clinical investigator at the National Cancer Institute. The federal cancer institute said it had 28 studies with the drug ongoing in different types of cancer.
After learning of the possible risk, the NCI held several meetings during the summer with experts in prion disease and from the Food and Drug Administration, said Louise Grochow, a senior manager at the National Cancer Institute. Dr. Grochow said the risk was deemed small, and that no significant changes would be made to the design of the studies. However, she added that the NCI would require more thorough neurological evaluation of patients. "So far, there is no evidence that the risk is being played out," said Dr. Grochow.
Proteasome inhibitors aren't the same as protease inhibitors, drugs that are used widely to treat HIV infection and AIDS.
Dr. Lindquist and co-workers found the proteasome effect while studying the molecular basis of prion diseases, which include mad cow and variants that affect humans and deer.
The diseases have been linked to misshapen prion proteins, which accumulate around nerve cells killed off by the condition. However, Dr. Lindquist reports Friday in the journal Science that normal prion proteins were able to cause nerve degeneration when they were present inside a cell's liquidy interior, or cytoplasm.
The proteins were able to accumulate after the scientists applied proteasome-blocking chemicals to the cells. The proteasome is the cellular machinery that normally digests proteins.
The cause of the brain disease has been a major scientific question, and Dr. Lindquist said her paper suggested a possible explanation, though conclusive proof was lacking. Jiyan Ma of Ohio State University, who carried out much of the work, said it could be that one form of the prion protein causes the symptoms, while another form lets it pass between animals. "We think the transmission and the toxicity are separate," said Dr. Ma.
- Unique mechanism of action – inhibition of the proteasome – represents potential new hope for patients with multiple myeloma -
Cambridge, MA, June 11, 2002 – Millennium Pharmaceuticals, Inc. (Nasdaq: MLNM) today announced the initiation of a pivotal phase III clinical trial of VELCADE (formerly known as MLN341, LDP-341 and PS-341) in patients with multiple myeloma, the second most common hematologic cancer. The company also announced they have filed the trade name VELCADE, for trademark registration, and will use VELCADE as the naming convention for MLN341. The trade name will be subject to approval by the FDA and other regulatory authorities during the NDA/MAA submission and approval process. The randomized open-label, multi-center, international phase III trial will compare VELCADE with high-dose dexamethasone, a commonly used therapy, to assess the efficacy and safety of VELCADE in patients with multiple myeloma whose disease has progressed after one to three prior therapeutic regimens.
"The initiation of this pivotal phase III trial not only represents an important milestone in the development of the lead compound of our oncology franchise, but an important company goal as well," said John Maraganore, Ph.D., senior vice president, strategic product development at Millennium Pharmaceuticals. "The recent fast track designation of VELCADE coupled with the start of this trial further validates our commitment to developing breakthrough therapeutic products."
The phase III trial is being planned for over 60 sites in the United States, Canada and Europe in approximately 600 patients with multiple myeloma whose disease has progressed despite one to three previous therapies. Patients will be randomly assigned to receive either VELCADE™ (bortezomib) for Injection or high-dose dexamethasone. The primary endpoint of the study is time-to-disease progression with secondary endpoints including measurements of clinical benefit, quality of life, survival and response rates. The safety of the two drugs also will be compared. Patients in the phase III trial receiving high-dose dexamethasone whose disease continues to progress will be able to receive VELCADE in a companion single-arm clinical trial of VELCADE.
VELCADE is designed to specifically block proteasomes, which are enzyme complexes in the cell responsible for breaking down a variety of proteins, including many that regulate cell division. Laboratory studies have suggested that by inhibiting the proteasome, VELCADE in cancer cells disrupted regulating proteins and ultimately induced apoptosis (programmed cell death).
"The preliminary phase II study results in patients with multiple myeloma have encouraged us to move forward with this pivotal phase III study. With its new and unique mechanism of action, inhibiting the proteasome, VELCADE represents a possible new approach in the fight against multiple myeloma," said principal study investigator Kenneth Anderson, M.D., from Dana-Farber Cancer Institute in Boston, MA. "Patients battling multiple myeloma, a disease with an average patient survival time of three to five years, need new treatment options."
Recent Clinical Data Preliminary data presented at the recent American Society of Clinical Oncology (ASCO) meeting from the first cohort of a phase II trial of VELCADE in patients with multiple myeloma whose disease has relapsed and was progressing following multiple prior therapies, included the following results:
Overall, 77 percent of patients (54 of 70 evaluable patients) in the study experienced stabilization of the disease or a reduction in their (M) protein levels, a substance in the blood that physicians use to evaluate multiple myeloma tumor burden, after receiving VELCADE for up to 24 weeks; Specifically, 20 percent (14 out of 70 evaluable patients) had a greater than 90 percent reduction in their (M) protein levels; and 47 percent of patients (33 out of 70 evaluable patients) had at least a 25 percent reduction; Overall, for the population in this study, the median time to progressive disease (TTP) was greater than 6.2 months, with the majority of patients still not experiencing progressive disease. Side effects were manageable and predictable and included fatigue, diarrhea, reduced platelets and peripheral neuropathy.
In addition, in preliminary data from two ongoing phase I studies of VELCADE™ (bortezomib) for Injection in patients with advanced solid tumors, VELCADE in combination with the common chemotherapies Gemzar® (gemcitabine) and Camptosar® (irinotecan hydrochloride injection) was well-tolerated, with patients experiencing manageable and predictable side effects including reduced platelets, diarrhea and neutropenia. Certain patients in these trials with pancreatic, lung and colorectal cancers also experienced early signs of potential anti-tumor activity. VELCADE is also being combined with Taxotere® (docetaxel) in three phase I/II studies in patients with prostate, lung and breast cancer.
For more information about VELCADE clinical trials, patients and physicians can contact Millennium’s Medical Information Center at (800) 589-9005.
About Multiple Myeloma Multiple myeloma is a cancer of the blood in which white blood cells called plasma cells, normally responsible for the production of antibodies (proteins that fight infection and disease), are overproduced in the bone marrow – the tissue inside the bone that manufactures all blood cells. The proliferation of these abnormal plasma cells, known as myeloma cells, causes decreased production of normal red and white blood cells, and of normal disease-fighting antibodies, as well as destruction of bone leading to numerous fractures. The malignant plasma cells produce a paraprotein, (M) protein, that is responsible for many of the complications of the disease, including kidney failure.
Multiple myeloma is the second most common cancer of the blood and although the disease is predominantly a cancer of the elderly (the peak age of onset is 65 to 70 years of age), recent statistics indicate both increasing incidence and younger age of onset. About 11,200 people in the United States (5,800 men and 5,400 women) are expected to die of multiple myeloma this year. The disease is about twice as common in males as females. Among African Americans, multiple myeloma is one of the top 10 leading causes of cancer death.
Millennium's Oncology Franchise Millennium is committed to pursuing oncology as a core franchise area, dedicating significant resources and capabilities in the areas of technology, scientific expertise and strategic business development. To this end, Millennium has already produced a deep oncology pipeline that ranges from multiple novel targets to commercialized therapeutic and diagnostic products. VELCADE™ (bortezomib) for Injection, a first-in-its-class small molecule, designed to inhibit the proteasome, has received fast track designation from the FDA and is currently in phase III clinical trials for multiple myeloma and phase I trials for solid tumors. Among the most advanced clinical compounds in addition to VELCADE are MLN591, an anti-PSMA antibody currently in phase I clinical trials for advanced prostate cancer and MLN576 (XR11576), a small molecule with DNA-targeting activity in phase I trials for solid tumors. In addition, MLN518, a first-in-class RTK inhibitor has received fast track designation from the FDA and recently entered phase I trials for acute myeloid leukemia. The Campath® (alemtuzumab) monoclonal antibody, a therapeutic developed from a former joint venture of Millennium and ILEX Oncology, Inc., is commercially available in both the United States and a number of European countries. A Millennium alliance partner and licensee is in the process of developing and commercializing Melastatin®, a melastatin detection product for melanoma developed through our predictive medicine efforts.
About Millennium Millennium Pharmaceuticals, Inc., a leading biopharmaceutical company, applies its comprehensive and integrated science and technology platform for the discovery and development of breakthrough therapeutic and predictive medicine products with a goal of delivering personalized medicine. Millennium is primarily focusing its research, development and commercialization activities in four key areas: cardiovascular, oncology, inflammation and metabolic diseases. Through the industrialization of its gene-to-patient platform, Millennium is striving to accelerate the process of drug discovery and development. Headquartered in Cambridge, Mass., Millennium currently employs more than 2,000 people.
This press release contains "forward-looking statements," including statements about our growth and future operating results, discovery and development of products, potential acquisitions, strategic alliances and intellectual property. Various risks may cause Millennium's actual results to differ materially, including: adverse results in our drug discovery and clinical development processes; failure to obtain patent protection for our discoveries; commercial limitations imposed by patents owned or controlled by third parties; our dependence upon strategic alliance partners to develop and commercialize products and services based on our work; difficulties or delays in obtaining regulatory approvals to market products and services resulting from our development efforts; and the requirement for substantial funding to conduct research and development and to expand commercialization activities. For a further list and description of the risks and uncertainties we face, see the reports we have filed with the Securities and Exchange Commission. We disclaim any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.
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Gemzar® is registered trademark of Eli Lilly and Company. Camptosar® is a registered trademark of Pharmacia Corporation. Taxotere® is a registered trademark of Aventis Pharmaceuticals, Inc. Campath®is a registered trademark of ILEX Pharmaceuticals, L.P.
source; http://www.mlnm.com/news/2002/06-11--0.html 18oct02
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