Late-stage clinical biopharmaceutical company Sophiris Bio has received positive feedback from the European Medicines Agency (EMA) for the Phase III localised prostate cancer clinical trial design.

The trial will evaluate the potential of topsalysin (PRX302), a first-in-class, pore-forming protein, as a targeted focal therapy for the treatment of patients with intermediate-risk localised prostate cancer.

Sophiris Bio president and CEO Randall Woods said: “Based on the safety profile of topsalysin in 451 patients in our clinical development programme, along with the efficacy seen in our Phase II studies in localised prostate cancer, we approached the EMA with our proposed study design for a single Phase III trial to support registration in Europe, and we are pleased to have now obtained formal feedback from the agency.

“We believe that data from a single Phase III trial, if successful, will be sufficient to support market approval in Europe.”

For the agreed Phase III study design, patients with a confirmed diagnosis of intermediate risk disease will be enrolled.

As part of the study, about 700 men who meet the eligibility criteria will be equally randomised to receive a single administration of either topsalysin or placebo.

The trial’s primary endpoint will be the proportion of patients at 12 months who have failed treatment.

Topsalysin is a first-in-class transmembrane pore-forming protein and was genetically modified to be activated only by enzymatically-active PSA produced in bulk quantities in men with prostate cancer.

Prostate cancer is the second most common form of cancer in men in the US and an estimated 175,000 new cases were reported this year.