Efficacy of Testosterone Suppression with Sustained-Release Triptorelin in Advanced Prostate Cancer

Area of Science:

• Oncology
• Endocrinology
• Pharmacology

Background:

• Androgen deprivation therapy (ADT) is a standard treatment for advanced prostate cancer (PC).
• Current ADT aims for testosterone suppression below 50 ng/dl, but lower levels may improve outcomes.
• Triptorelin, a gonadotropin-releasing hormone (GnRH) agonist, is used in ADT.

Purpose of the Study:

• To evaluate the efficacy of 1-, 3-, and 6-month sustained-release (SR) triptorelin formulations.
• To assess the ability of triptorelin SR to suppress serum testosterone concentrations below 20 ng/dl.
• To analyze success rates of testosterone suppression across different triptorelin SR formulations.

Main Methods:

• Pooled retrospective analysis of 920 male PC patients from 9 prospective studies.
• Patients received triptorelin SR formulations for 2-12 months.
• Primary endpoint: serum testosterone concentration, with a target threshold of <20 ng/dl.

Main Results:

• After 1, 3, 6, 9, and 12 months, 79%, 92%, 93%, 90%, and 91% of patients achieved testosterone <20 ng/dl.
• Success rates for 1-, 3-, and 6-month formulations ranged from 80-92%, 83-93%, and 65-97%, respectively.
• Median testosterone levels at study end were 2.9, 5.0, and 8.7 ng/dl for 1-, 3-, and 6-month formulations.

Conclusions:

• Triptorelin SR formulations effectively suppress serum testosterone to <20 ng/dl in most PC patients.
• Routine monitoring of testosterone levels in PC patients on ADT is recommended.
• Further research is needed to determine the clinical benefits of very low testosterone levels.