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(Drug information on 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).
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.
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.