The Bayer Corporation announced recently that Viadur
(leuprolide acetate implant), a once-yearly implant for the palliative treatment
of advanced prostate cancer, is now available in the United States. The new
product offers patients 12 months of continuous testosterone suppressionan
alternative to the 1-, 3-, or 4-month injections currently in use.
The Viadur implant is inserted under the skin of the patient’s
upper arm during an office procedure. It provides steady serum concentrations of
leuprolide throughout the 12-month dosing period. Leuprolide is the primary drug
used for testosterone-suppression therapy of advanced prostate cancer.
"Viadur was effective in suppressing testosterone below the
castrate threshold. It also was generally well tolerated in open-label clinical
trials, in which 90% of patients chose to continue Viadur therapy for a second
12-month period," said James Gottesman, md, of the University of Washington
In two open-label, multicenter studies, 131 patients with
advanced prostate cancer were treated with the 12-month leuprolide implant and
evaluated for up to 2 years. Following the initial surgical insertion of the
implant, mean serum testosterone concentrations decreased to therapeutically
desirable levels by week 4 in 99% of the patients in the studies. Once serum
testosterone suppression was achieved, testosterone levels remained suppressed
for the duration of the 12-month treatment phase.
The most common side effects associated with the use of
once-yearly leuprolide were hot flashes (67.9%), asthenia (7.6%), gynecomastia
(6.9%), depression (5.3%), and sweating (5.3%). The most common local side
effects were bruising (34.6%) and burning (5.6%).