May 14, 2001
MEDIA CONTACT: Vanessa Wasta
University of Pittsburgh Medical Center
Researchers at Johns Hopkins and the University of Pittsburgh report promising results in tests of a new prostate cancer drug known as ABT-627 made by Abbott Laboratories (Abbott Park, IL). In a phase II multinational clinical trial, the drug delayed progression of advanced prostate cancer with few side effects in men no longer responding to hormone therapy. Results of the study are expected to be announced at the American Society of Clinical Oncology (ASCO) annual meeting in San Francisco on May 14, 2001. Results are published in abstract #694 in the ASCO Program/Proceedings.
"For patients who have failed hormone therapy, and whose prostate cancer is progressing and may have spread to other parts of the body, the options for treatment are limited right now," says Michael Carducci, M.D., assistant professor of oncology at the Johns Hopkins Oncology Center and director of the study. "This low-toxicity drug may delay the need for more aggressive, but non-curative treatments like chemotherapy or radiation in these patients."
In one group of 244 patients who received either oral ABT-627 or a placebo, results show that progression of disease was delayed 69 days more in those on ABT-627 than in those on placebo. Those taking the drug took twice as long for their prostate specific antigen (PSA) to rise by more than 50 percent, an indicator of disease progression. Relatively few patients experienced side effects, such as a stuffy nose, headache and swelling, according to Carducci.
Related studies of 419 patients (including the 244 patients in the first group) led by Joel Nelson, M.D., professor and chair of urology at the University of Pittsburgh School of Medicine, conclude that ABT-627 also stabilizes spread of prostate cancer (metastasis) to the bone. Often a painful effect of late-stage prostate cancer, bone metastasis signifies a poor prognosis in prostate cancer patients. In the study, patients who got a placebo experienced increases in biochemical markers indicating worsening bone metastasis, whereas levels of those markers remained stable in patients receiving ABT-627.
(Abstract # 12)
"These results are compelling," says Nelson. "Since prostate cancer so frequently spreads to the bone, treatments need to impact the disease at this stage. In men treated with ABT-627, there was little to no increase of markers indicating progression of the prostate cancer in the bone."
ABT-627 blocks endothelin, a protein best known as a potent blood vessel constrictor. Prostate cancer cells secrete excess amounts of endothelin, which may act as a growth enhancer and promote spread of the cancer to the bone.
"Standard treatment for these patients is to radiate when there is pain," says Carducci. "Some men may want more aggressive treatments, others are looking for alternatives that are less toxic." To fully delineate the drug’s role in prostate cancer treatment, larger clinical trials will be conducted to determine its potential and effectiveness in combination with or prior to hormonal therapy.
"Prostate cancer is a chronic disease requiring chronic therapy," says Nelson. "An oral, once-a-day medication, like the one we studied, is ideal."
Prostate cancer is diagnosed in approximately 180,400 men every year, and close to 32,000 die each year from the disease. Most prostate cancers are found in the early stages of the disease and are highly curable. Studies suggest that the average life expectancy of men with hormone-resistant, progressive and metastatic prostate cancer is 12 months.
In addition to Carducci and Nelson, other participants in this research are Robert J. Padley, Todd Janus, and Richard Hippensteel.
Support for the study discussed in this press release was provided by Abbott Pharmaceuticals. Carducci and Nelson are paid consultants to Abbott. The terms of this arrangement are being managed by the Johns Hopkins University and University of Pittsburgh School of Medicine in accordance with their conflict of interest policies.
American Society of Clinical Oncology (ASCO) Program/Proceedings, Abstract #694 and #12, Volume 20, 2001.
Related Web Sites:
Johns Hopkins Oncology Center: www.hopkinskimmelcancercenter.org
The Brady Urological Institute at the Johns Hopkins Medical Institutions: http://prostate.urol.jhu.edu/
University of Pittsburgh Cancer Institute: www.upci.upmc.edu
American Society of Clinical Oncology: www.asco.org