I would like to call your attention to a misleading statement
that appeared in the Industry Watch section of the October, 1995,
issue of Oncology News International under the title "Casodex
Approved for Prostatic Cancer" (page 23).
The statement reads: "The company reports that after a median
follow-up of 95 weeks, Casodex [in combination with an LHRH agonist]
was similar to flutamide (Eulexin) in its effect on survival."
You should be aware that the Professional Information Brochure
for Casodex from Zeneca Pharmaceuticals actually states the following:
"At a median follow-up of 95 weeks, time to treatment failure
with Casodex-LHRH analog therapy was not dissimilar when compared
to Flutamide-LHRH analog therapy" (page 4).
Primary Endpoint
This clarification is quite important, as the pivotal trial that
compared Casodex (bicalutamide) to Eulexin and formed the basis
of Casodex's approval by the FDA did not, in fact, show improvement
in either time to disease progression or survival.
Rather, this study utilized as its primary endpoint, the unusual
endpoint of time to treatment failure. This is defined in the
study as "withdrawal from the study for any reason."
Time to treatment failure is generally not accepted by the medical
community as a primary efficacy endpoint.
In contrast, Schering-Plough's Eulexin (flutamide) has been shown
in several major studies to delay progression and extend survival
time for advanced prostate cancer patients. One pivotal study
conducted by the National Cancer Institute showed that, in patients
with minimal metastatic bone disease, Eulexin, when initiated
with an LHRH agonist, delayed progression by 29 months and increased
overall survival by 19 months.
Side Effects
In a follow-up item on the approval of Casodex that appeared in
the November, 1995, issue of Oncology News International (page
24), your reporter refers to findings from the Casodex study on
side effects.