Sophiris Bio, Inc. announced that the first patients have been dosed in a Phase 2a proof of concept trial of PRX302 as a treatment for localized low to intermediate risk prostate cancer. The Phase 2a proof of concept study is a single-center, open-label study that will enroll approximately 20 patients. Previously obtained multi-parametric magnetic resonance imaging (mpMRI) of tumor lesions in each patient's prostate, mapped to real-time three-dimensional transrectal ultrasound (TRUS), will be used in the study to guide the injection of PRX302 to treat a single, histological-proven, clinically significant lesion area in each patient's prostate.

Although the primary objective of the study is safety and tolerability, the key efficacy variable is the change in the treated clinically significant lesion on biopsy after six months. PRX302 has the potential to provide a focal targeted therapy for the ablation of localized prostate cancer while potentially avoiding many of the complications and side effects associated with whole gland radical treatments. The increasing use of multi-parametric magnetic resonance imaging (mpMRI) and advances in mapping previously obtained mpMRI images with live 3D ultrasound images enable the physician to more accurately locate tumors within the prostate when taking biopsies.

This increases the accuracy with which men with clinically significant lesions are identified. It also enables the injection of PRX302 directly into previously identified clinically significant tumors located within the prostate. The targeted focal treatment of prostate cancer is in line with current treatments for solid tumors, such as breast or liver, where the goal is to remove the tumor and preserve as much of the organ as possible.