A 12-month clinical study of LA-2585 (45.0 mg): a new 6-month subcutaneous delivery system for leuprolide acetate for the treatment of prostate cancer.
OBJECTIVE
The safety, efficacy and pharmacokinetics of LA-2585, a new 6-month subcutaneous depot of leuprolide acetate (Atrix Laboratories, Fort Collins, Colorado) were investigated in patients with prostate cancer.


METHODS
In this 12-month, open label, multicenter study 111 patients with adenocarcinoma of the prostate were administered 45.0 mg LA-2585 subcutaneously once every 6 months. The primary efficacy parameter was serum testosterone 50 ng/dl or less. Leuprolide acetate pharmacokinetics were analyzed in a subset of 28 patients.


RESULTS
Of the 111 enrolled patients 103 (93%) completed the 12-month study. Eight patients withdrew due to nonmedical reasons in 1, disease progression in 5 and cardiovascular disease in 2. By day 28, 108 of the 109 remaining patients (99%) achieved testosterone suppression, while 1 who never attained suppression was withdrawn at day 85. Mean time to castrate suppression was 21.2 days (median 21). At study completion 102 of 103 patients (99%) were below medical castrate testosterone levels of 50 ng/dl (mean +/- SE 12.3 +/- 2.1 ng/dl) with 91 of 103 (88%) at less than 20 ng/dl. Mean luteinizing hormone decreased from 6.98 +/- 0.48 mIU/ml at baseline to 0.23 +/- 0.14 mIU/ml at month 12. Luteinizing hormone was consistently below 1 mIU/ml. Mean prostate specific antigen decreased 97% from 39.8 +/- 21.5 ng/ml at baseline to 1.2 +/- 0.3 ng/ml at 12 months. No clinically significant flare reactions were observed. The most common treatment related adverse event was mild to moderate hot flashes.


CONCLUSIONS
LA-2585 (45.0 mg depot) consistently produced and maintained safe and effective serum testosterone suppression with total serum testosterone well below the medical castrate level of less than 50 ng/dl.
Crawford
E David
ED
Section of Urologic Oncology, University of Colorado Health Sciences Center, Aurora, Colorado 80045, USA. david.crawford@uchsc.edu
Sartor
Oliver
O
Chu
Franklin
F
Perez
Ramon
R
Karlin
Gary
G
Garrett
J Steve
JS
D000230:Adenocarcinoma / Q000188:drug therapy*; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage* / Q000493:pharmacokinetics; D016503:Drug Delivery Systems; D006801:Humans; D016729:Leuprolide / Q000008:administration & dosage* / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000188:drug therapy*; D040521:Subcutaneous Tissue; D013997:Time Factors
D018931:Antineoplastic Agents, Hormonal; D016729:Leuprolide