Less injections by androgen scrutinisation

Chemical or surgical castration is a key strategy in patients with locally advanced or metastatic prostate cancer. The goal is to eliminate gonadal testosterone production, so called castration. Currently, both chemical and surgical castration are considered equal modalities to achieve castration. Chemical castration is achieved by administering Luteinizing Hormone Releasing Hormone (LHRH) agonists on a regular basis. However, after prescribing LHRH agonists, physicians do not monitor the testosterone levels routinely. Moreover, current dosing regimens are manufacturer recommended. Several studies have shown that serum testosterone levels remain longer at or below castrate levels when 3monthly depot injections of LHRH agonists are administered. This opens opportunities for a personalized way of dosing LHRH agonists depending on the testosterone level. However, in the performed testosterone based dosing studies only the LHRH agonist leuprorelin has been investigated. The current study will be initiated to evaluate a testosterone based dosing regimen with depot injections of goserelin 10.8 mg for all eligible patients as well as subgroups of patients. Based on the performed testosterone based dosing studies with leuprorelin we expect that the dosing interval of depot injections of goserelin 10.8 mg can be prolonged to 5 or 6 months. An effective personalized treatment regimen will probably lower the treatment burden (for patients) and treatment costs (for society) while treatment goals are still achieved.

The primary objective of this study is to determine the possibility to extend the dosing interval of goserelin 10.8 mg with a testosterone-based dosing regimen compared to regular treatment with 3-monthly based goserelin 10.8 mg injections during 24 months follow-up.

Control group: once every 3 months

Intervention group: dependent on the testosterone levels in the patients

Extending the dosing interval of goserelin 10.8 mg injections