Highlights from the American Society of Clinical Oncology (ASCO) 2007
Meeting
Satraplatin, an oral chemo-therapy, is a beneficial second-line
medication for metastatic prostate cancer, according to a randomized
phase III trial. Background: Chemotherapy (usually Taxotere) is
administered for metastatic androgen-independent prostate cancer. Once
first-line chemotherapy loses its effect, there are no standard back-
up agents. Sternberg et al randomized 660 men, whose cancer
progressed after first-line chemotherapy, to receive either
Satraplatin or placebo. Results: Men receiving Satraplatin benefited
from a 42% improvement in progression-free survival. Also,
Satraplatin was superior in terms of prolonged time to pain
progression, improved pain response, likelihood of tumor shrinkage,
and PSA response rate. Only 2.5% of pts stopped treatment due to side
effects.
Comment: If approved, oral Satraplatin will provide much needed
benefit for pts with advanced disease. Sternberg, C, PASCO, #5019.
Abiraterone, an oral inhibitor of adrenal androgen synthesis,
successfully treats androgen independent disease (AIPC), according to
researchers at UCSF. Background: Once prostate cancer becomes
resistant to androgen deprivation therapy, other than chemotherapy,
there are no FDA-approved drugs. Ryan et al have enrolled 24 men to
their Phase I/II trial to date, 16 of which had been previously
treated and had become resistant to ketoconazole, a second-line
hormone agent. Results: 24 of 25 men had a PSA decline, 12 had PSA
declines of more than 50%. Three had a 90% drop. Of the men with
prior ketoconazole exposure, 7 of the 16 responded.
Comment: This non-chemotherapy agent would fit nicely into the
treatment scheme for pts with AIPC who want to avoid chemotherapy.
Ryan, C, PASCO, #5064.
Antiangiogenesis agents, such as Avastin AND Thalidomide, greatly
enhance the effectiveness of Taxotere chemotherapy, according to a
study by the NCI. Background: Taxotere is an effective FDA-approved
drug for metastatic prostate cancer, but it does not help everyone and
it's duration of benefit tends to be limited. Ning and colleagues
treated 39 men with Taxotere in combination with Avastin and
thalidomide. Results: 34 of 39 men had a >50% decline in PSA, and 26
pts (67%) had a >80% PSA decline. The duration of benefit was also
>50% longer than what has been noted for single-agent Taxotere. Side
effects, including blood clots, fever,bleeding, and fainting occurred
in a small percentage of men.
Comment: Avastin, used in conjunction with chemotherapy, is currently
the standard of care for colon, lung and breast cancer. Dr. Ning has
reported the most promising results to date, utilizing the combination
of Avastin, Thalidomide, and Taxotere. We await the results of large
phase III studies that are already underway.
Ning, Y, PASCO, # 5114.
