FDA approves twice-yearly GnRH formulation for advanced prostate Ca

March 25, 2010

The FDA has approved triptorelin pamoate (Trelstar) 22.5 mg, a new twice-yearly formulation for the palliative treatment of advanced prostate cancer.

The FDA has approved triptorelin pamoate (Trelstar) 22.5 mg, a new twice-yearly formulation for the palliative treatment of advanced prostate cancer.

The drug releases triptorelin pamoate, a GnRH agonist, over a prolonged period and, in turn, suppresses testosterone production for 6 months. It is administered via the Mixject delivery system, which uses a 21-gauge needle, and thereby offers easy administration with low incidence of injection-site pain, according to Watson Pharmaceuticals, which manufactures both the drug and the delivery system.

The approval is based on a 12-month phase III study in which triptorelin produced a mean testosterone serum level of 12.8 ng/dL from month 2 through month 12. By day 29, 97.5% of patients achieved castrate level, and median PSA was reduced by 96.4% by the end of the study.

In related news, FDA has accepted for review Abbott Laboratories’ supplemental new drug application of a new 6-month, 45-mg formulation of leuprolide acetate for depot suspension (Lupron Depot) for the palliative treatment of advanced prostate cancer.

Abbott’s submission is supported by new data from a 48-week study involving 300 patients with prostate cancer. Patients received a total of two injections, 24 weeks apart, and were followed for nearly 1 year to evaluate efficacy and safety. Overall, testosterone suppression with this new 45-mg, 6-month depot formulation was sustained in patients throughout the treatment period.