Sophiris Bio has concluded enrolling patients in a Phase llb study that will evaluate the safety and tolerability of targeted intraprostatic administration of topsalysin to treat men with clinically significant localised prostate cancer.
The multi-centre, open-label, clinical trial employs previously obtained MRI images of each patient’s prostate co-registered to real-time 3D ultrasound to deliver topsalysin directly into and around a pre-identified clinically significant tumour.
Biopsy data from all patients dosed with the first administration of topsalysin is expected to be available by the first half of next year.
Topsalysin (PRX302) is a new transmembrane pore-forming protein genetically updated to be activated only in the presence of enzymatically-activeprostate-specific antigen (PSA), which is found only within the prostate.
The Phase llb study investigator and Imperial College London & Imperial College Healthcare NHS Trust Urology chair Hashim Ahmed said: “Over the next few months, men in the trial will undergo follow-up biopsies of the prostate and, if necessary, may undergo repeat topsalysin dosing.”
The study also features an option to re-treat patients with a second dose of topsalysin, with an additional targeted biopsy to occur six months following the second dose.
For taking part in the second dose, the patient cannot have experienced a clinically significant adverse event attributable to topsalysin or the dosing procedure from the first dose.
The patient will also require to have had a clinical response from the first dose but still have the presence of a clinically significant lesion area, while the patients who have a complete response to the first dose will not receive a second dose.