LAS VEGAS--A new, longer duration formulation of an LHRH (luteinizing hormone releasing hormone) analogue for advanced prostate cancer offers more convenient dosing and appears to be safe and effective.
Two randomized studies presented at the American Urological Association annual meeting compared the new formulation, a 10.8 mg depot of goserelin(Drug information on goserelin) acetate (Zoladex), with the 3.6 mg depot of the same agent.
At a poster session, Frans N.J. Debruyne, MD, University Hospital, Nijmegen, the Netherlands, said that while the 3.6 mg depot requires monthly visits to physician offices or clinics, the 10.8 mg depot is replaced at 3 months, an interval coinciding perfectly with the follow-up schedule of patients with metastatic prostate cancer.
In the two comparative studies presented by Dr. Debruyne, involving a total of 160 patients with advanced prostate cancer, patients received either a single 10.8 mg depot or three consecutive 3.6 mg depots over weeks 0 to 12. Subsequently, all patients received three consecutive 10.8 mg depots over weeks 12 to 48.
Evaluations of the testosterone profiles of patients receiving the different regimens revealed similar patterns. The expected testosterone level rise in the first week was followed by rapid declines to within the castrate range by day 21. Mean testosterone levels in both studies during weeks 4 to 12 were 0.64 nmol/L and 0.69 nmol/L for the 10.8 mg and 3.6 mg depot groups, respectively (P = .53).
Levels remained in the castrate range (0 to 2.50 nmol/L) throughout the 48-week study period, Dr. Debruyne told Oncology News International.
Adverse events (mostly hot flushes) for patients receiving the 10.8 mg depot were comparable to those seen in the 3.6 mg depot group. Also, the depot was well tolerated locally, with injection site reactions reported for only 0.3% (2) of 614 administrations.