STEBA decided to develop WST11 that is soluble in aqueous solutions. The property of WST 11 make it safer and better candidate for therapeutic applications.

The aim of this clinical trial is to evaluate the efficacy and safety of the WST09-mediated vascular-targeted photodynamic therapy (VTP) in patients with localized prostate cancer recurrent after external radiation therapy or temporary (High Dose Rate, or HDR) brachytherapy.

This is a multicentre, open labelled, phase II/III, 6-month clinical trial with an additional follow-up at Month 12, aiming to determine the efficacy and tolerability of the WST09-mediated VTP treatment. This treatment consists of an I.V. infusion of WST09 (2 mg/kg), in combination with per-cutaneous interstitial illumination using laser light (wavelength at 763nm) delivered through optical fibres positioned through the perineum in the prostatic lobes.

Patients who are eligible to participate in the study must have a clinically diagnosed positive biopsy of the prostate (up to stage T2b-N0-M0) diagnosed after external radiotherapy or temporary brachytherapy (no seeds), and present with increasing PSA levels on three consecutive occasions (at least 3 months apart) post-radiation treatment.

Inclusion Criteria:

Histologically proven localized prostate cancer after receiving external radiation therapy;

Exclusion Criteria:

Patients unwilling or unable to give informed consent; Patients who received or are receiving chemotherapy; Patients previously treated with HIFU, cryotherapy, other salvage treatments, or with a trans-urethral resection of the prostate (TURP); Patients whose previous radiation therapy caused extensive cystitis and/or proctitis.

Patients suspected of Disseminated Intravascular Coagulation (DIC). Patients with prior history of coronary artery disease, angina pectoris, myocardial infarction, coronary angioplasty or coronary artery bypass graft, severe valvulopathy, cardiac failure, artrial fibrillation and / or sustained arrhythmia.

Patients whose cardiac status does not allow general anesthesia. Patients with history of thromboses or thrombo-embolisms. Patients with history of stroke or transient ischemic attack.