A depot formulation containing a bioresorbable, controlled-release, calcium sulphate-based paste of the nonsteroidal antiandrogen 2-hydroxyflutamide (2-HOF) with potential antineoplastic activity. Upon injection into the tumor site in the prostate, 2-hydroxyflutamide depot slowly releases 2-HOF, which competitively binds to androgen receptors (ARs), blocking the binding of dihydrotestosterone (DHT). This may inhibit androgen-dependent DNA and protein synthesis, resulting in tumor cell growth arrest and decreased cellular proliferation. In addition, 2-HOF inhibits nuclear uptake of androgen in androgen-responsive tissues.