Liproca Depot: A New Antiandrogen Treatment for Active Surveillance Patients

Abstract

Background: There is increasing interest in nonmorbid treatments for low- and intermediate-risk prostate cancer with fewer side effects than surgery or radiotherapy. Objective: To investigate the tolerability, safety, and antitumor effects of the intraprostatic NanoZolid depot formulation Liproca Depot (LIDDS AB, Uppsala, Sweden) with antiandrogen 2-hydroxyflutamide (2-HOF) in men with low- or intermediate-risk localized prostate cancer managed with active surveillance. Design, setting, and participants: This clinical phase 2b trial, LPC-004, involved 61 patients. The 2-HOF-containing formulation Liproca Depot was injected transrectally into the prostate under ultrasound guidance. A single dose of 35% or 45% of the prostate volume (study part 1) and a fixed dose of 16 or 20 ml (study part 2) of the formulation were evaluated. Outcome measurements and statistical analyses: The primary endpoints were tolerability and the reduction in serum prostate-specific antigen (PSA) 5 mo after injection. Antitumor effects were evaluated with magnetic resonance imaging (MRI) and prostate biopsies. Quality of life was assessed using a validated questionnaire (International Prostate Symptom Score). Results and limitations: All doses were safe and well tolerated, without hormonal side effects. In part 2 of the study, the PSA reduction was greatest for the group receiving 16 ml, with an average decrease of 14%, an