Pharmacodynamic equivalence of a decapeptyl 3-month SR formulation with the 28-day SR formulation in patients with advanced prostate cancer.
OBJECTIVE
The objective of the study was to assess the pharmacodynamic equivalence of LHRH analogue triptorelin 3-month and 28-day SR formulations.


METHODS
Patients with documented locally advanced or metastatic prostate cancer were randomized to receive one injection of the 3-month formulation (n = 63) or three injections at 28-day intervals of the 28-day formulation (n = 68). Group-chemical castration rates defined as the percentage of patients reaching a testosterone plasma level </=0.5 ng/ml were compared at D84 (i.e., 3 x 28 days). Testosterone, LH and triptorelin plasma profiles, and change from baseline in plasma PSA were assessed over 3 months (from baseline to D91).


RESULTS
Chemical castration rates were 98 and 96% in the 3-month and 28-day formulation groups, respectively, with confidence interval (two-sided 94.2% CI) of [-8.1%; 9.6%]. Median times to reach chemical castration were 18.8 and 18.5 days (p = 0.86, log rank), respectively. Ratios for mean peak plasma levels and AUC(91) of the two formulations for both testosterone and LH fell within the [0.80; 1.25] equivalence interval. Mean PSA decreases from baseline at D91 were 91.0 and 91.7%, respectively (p = 0.73).


CONCLUSIONS
Treatments with the two triptorelin formulations over 3 months are pharmacologically equivalent.
Teillac
Pierre
P
Centre Hospitalier Universitaire Saint Louis, Paris, France. pierre.teillac@sls.ap-hop-paris.fr
Heyns
Christiaan F
CF
Kaisary
Amir V
AV
Bouchot
Olivier
O
Blumberg
Joëlle
J
D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D003692:Delayed-Action Preparations; D004334:Drug Administration Schedule; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008875:Middle Aged; D009376:Neoplasms, Hormone-Dependent / Q000097:blood / Q000188:drug therapy*; D009919:Orchiectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy*; D013739:Testosterone / Q000097:blood; D013810:Therapeutic Equivalency; D017329:Triptorelin Pamoate / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*
D018931:Antineoplastic Agents, Hormonal; D003692:Delayed-Action Preparations; D017329:Triptorelin Pamoate; D013739:Testosterone; D007986:Luteinizing Hormone