Leuprolide Acetate for Prostate Cancer: Achieving Effective Testosterone Suppression
Posted: Tuesday, June 8, 2021
Androgen-deprivation therapy is the standard of care for prostate cancer. However, the dosing schedules used to suppress testosterone to delay disease progression and improve survival are essential, emphasizing the duration of action. A recent report based on an analysis of U.S. clinical data, conducted by E. David Crawford, MD, and colleagues from the University of California San Diego, La Jolla, was published in The Journal of Urology.
“Adherence to dosing schedules to maintain testosterone suppression and regular monitoring of prostate-specific antigen/testosterone are important to avoid treatment failure, which may lead to decreased survival and increased costs due to greater health-care utilization,” noted the authors.
A retrospective observational analysis focused on data from 10,398 patients who received two or more injections of leuprolide acetate for injectable suspension (Gel-LA) delivered subcutaneously (2,038 patients) or leuprolide acetate for depot suspension (Msphere-LA) delivered intramuscularly (8,360 patients). Dosing was defined using either a 28-day month calendar (28, 84, 112, or 168 days for 1-, 3-, 4-, and 6-month formulations, respectively). Late dosing was defined as 4 days after the expected dose (day 32, 97, 128, or 194, respectively).
The study results indicated that 80% of Gel-LA and 86% of Msphere-LA injections were late for a 28-day month. For the extended month, 27% were late for both. The authors reported that 14% and 25% of Msphere-LA testosterone tests versus 10% and 18% of Gel-LA testosterone tests were above 50 ng/dL (odds ratio [OR] = 1.5). Therefore, for both the 28-day month and the extended month, Msphere-LA injections were 1.5 times more likely to have values higher than 50 ng/dL and 20 ng/dL. For the 28-day month, Msphere-LA injections resulted in testosterone levels higher than 50 ng/dL 13% versus 6% for Gel-LA (mean value, 46 ng/dL and 34 ng/dL, P = .002; OR = 2.4). For the extended month, Msphere-LA injections resulted in testosterone levels higher than 50 ng/dL in 20% versus 10% for Gel-LA (mean value = 76 ng/dL and 48 ng/dL, P = .0003; OR = 2.1).
Disclosure: For full disclosures of the study authors, visit auajournals.org.