[A phase II pharmacological study of leuprolide acetate 6-month depot, TAP-144-SR (6M), in treatment-Nazve patients with prostatic cancer who received a single subcutaneous or intramuscular injection].

The aim of this phase II study was to evaluate the pharmacokinetics, pharmacodynamics, efficacy, and safety of a 6- month depot formulation of a luteinizing hormone-releasing hormone (LH-RH) agonist, TAP-144-SR (6M), in Japanese treatment-naÏve patients with prostatic cancer. Each subject received a single subcutaneous or intramuscular injection of TAP- 144-SR (6M) and was monitored for 24 weeks. The primary endpoint was the change in serum testosterone levels. The serum testosterone level in six subjects who received 22.5 mg of TAP-144 (SR) subcutaneously decreased below the castrate level after 4 weeks and remained suppressed during the 24 weeks of follow-up. With regard to safety, TAP-144-SR (6M)was not associated with any additional concerns compared to those reported for the approved 1-month and 3-month depot formulations of TAP-144-SR. In addition, 30 mg of TAP-144-SR (6M) was administered subcutaneously to six subjects, and, on the basis of the results, the optimal clinical dosage of TAP-144-SR (6M) in Japan was considered to be 22.5 mg. Outcomes with 22.5mg TAP-144-SR (6M) administered intramuscularly were similar to those with TAP-144-SR (6M) administered subcutaneously.