Randomized Head-To-Head Prospective Study Of Pharmacokinetic And Pharmacodynamic Properties Of Leuprolide Acetate Formulations: 7.5 Mg Single Depot Subcutaneous Vs 7.5 Mg Intramuscular Microsphere.

e16048 Background: Leuprolide acetate (LA), a LHRH agonist, is the standard of care and used to suppress serum testosterone (T) to castrate level. Currently 2 LA formulations are available: a viscous liquid that forms a solid, controlled release implant (ATRIGEL) injected subcutaneously (SQ) or a microsphere intramuscular (IM) injection. The objective was to compare head-to-head the pharmacokinetics (PK) and pharmacodynamics (PD) of SQ-LA to IM-LA. Methods: In this open label, randomized, single dose, head to head study, healthy, male subjects (ages 18-55) received 7.5 mg LA in either IM formulation or solid depot SQ formulation. Blood samples were taken at 0, 0.25, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 24, 36, 48 h post-dose, every other day until day 7, and once a week until day 56. LA concentration in serum was analyzed with HPLC. PK parameters AUC, Cmax, Tmax (time to Cmax), t1/2 and concentration-time data were evaluated and descriptive statistics determined LA concentration over time. Concentration-time cu...