Sophiris plummets on doubts its prostate drug can clear Phase III

Taking an early look at data from an ongoing study of Sophiris Bio's ($SPHS) lead drug, independent advisers say the prostate-shrinking therapy didn't meet its predefined threshold for efficacy, casting a shadow over the biotech's only clinical asset.

The drug, PRX302, is in the midst of a 52-week trial on 479 patients to determine how well it can treat lower urinary tract symptoms of benign prostatic hyperplasia, or enlarged prostate. In a scheduled look at results, the trial's data monitoring committee reported that PRX302 wasn't performing as planned at 12 weeks, charting its effects with the International Prostate Symptom Score (IPSS).

The study's primary endpoint is improving IPSS at 52 weeks, and, despite the committee's note, Sophiris plans to carry out the trial to its conclusion, expecting to report final data in the fourth quarter of 2015. In its analysis, the committee reported no safety concerns, Sophiris said, and there have been no sepsis incidents in the trial.

The news hammered Sophiris' stock price, sending it down more than 80% to below 60 cents a share on Monday morning. The biotech, a little more than a year removed from a $65 million IPO, is trading at just 14% of its debut price.

Sophiris, formerly known as Protox, had planned this interim analysis to inform its design of future clinical trials, and the biotech is holding off on any final decisions until it has final data in hand.

PRX302 is still on tap for a Phase II proof-of-concept study in prostate cancer, the company said, planning to start the trial in the first quarter of next year.

- read the statement

Suggested Articles

Fifteen of the 22 patients in a gene therapy trial no longer needed transfusions, while the remainder needed fewer transfusions.

Argos Therapeutics is ending its kidney cancer trial and mulling options, including a merger or sale, to stay alive.

CNS Pharma says berubicin is the first anthracycline drug to cross the blood-brain barrier and could transform treatment of the highly invasive brain tumor.