Sophiris Bio Inc. (NASDAQ: SPHS) shares absolutely skyrocketed in Friday’s session following positive results from its mid-stage trial. The company announced the biopsy results from all 18 patients enrolled in the Phase 2a proof of concept study of topsalysin in localized prostate cancer.
The primary objective of the study was to evaluate the safety and tolerability, and the key efficacy variable was the change in the treated lesion on targeted biopsy after six months.
The one-time administration of topsalysin was well tolerated with no serious adverse events and no new safety signals being reported. Topsalysin demonstrated an ability to ablate tumor cells in 50% of patients (9/18 patients) six months after treatment in a patient population with pre-identified, clinically significant prostate cancer. The results support advancing topsalysin into a Phase 2 study to confirm dose and optimize delivery.
All patients enrolled completed the study. The biopsy data at six months detailed:
- Two men experienced complete ablation of their targeted tumor with no evidence of any tumor remaining at 6 months.
- Seven men experienced a partial response, defined as either a reduction in the maximum cancer core length or a reduction in Gleason pattern.
- Nine patients had no response to treatment.
Dr. Hashim Ahmed, principal investigator for the study, Division of Surgery and Interventional Sciences, University College London, commented:
It was impressive to observe complete tumor ablations in this proof of concept study. We have demonstrated that topsalysin can safely ablate prostate tumor cells, so these responses increase our confidence that topsalysin could obviate or prolong the time to the need for radical therapy in this patient population. With the experience from this study, we believe we can further improve responses by optimizing dosing topsalysin based on the size of the tumor and not the prostate and optimizing the delivery of topsalysin, which we will confirm in a larger Phase 2 study.
Shares of Sophiris were trading up over 80% at $2.12 on Friday, with a consensus analyst price target of $4.50 and a 52-week trading range of $0.67 to $3.85.