[Updated 5/25/16 2:35 pm with analyst comments. See below.] After advancing its experimental prostate drug to late-stage clinical trials, San Diego-based Sophiris Bio (NASDAQ: [[ticker:SPHS]]) has been assessing its strategic options before choosing the best way to continue the clinical trials and seek FDA approval.
In the past few weeks, Sophiris has raised additional capital to extend its operations for at least one more year. It also has hired an investment banking firm to help evaluate its strategic alternatives, and has cut its workforce in half to reduce its operating expenses.
[Updates with analyst comments here and below.] Sophiris is most likely seeking a big pharmaceutical partner to help underwrite additional clinical studies needed before the company can seek FDA approval for its sole drug candidate, according to Jason McCarthy, a biotech analyst for Maxim Group, a New York investment banking firm.
Sophiris moved to San Diego from Vancouver, BC, five years ago, after completing pre-clinical studies and related testing of PRX302, an experimental drug for treating men diagnosed with an enlarged prostate, formally known as benign prostatic hyperplasia (BPH).
Since then, Sophiris CEO Randy Woods says the company has advanced the drug, now known as topsalysin, through an initial Phase 3 clinical trial that demonstrated a statistically significant improvement in treating BPH symptoms. Men with BPH usually experience difficulty urinating, and get up frequently at night to urinate. The symptoms vary; their urinary stream may be weak or intermittent. In some cases, BPH can lead to infection, bladder stones, and reduced kidney function.
The current standard of care often begins with prescription drugs such as tamsulosin (Flomax), finasteride (Proscar), and tadalafil (Cialis), and moves to various surgical options, or laser, ultrasound, or microwave therapies. Potential side effects range from nausea and decreased sex drive from the drugs to urinary incontinence, sexual dysfunction, and infertility from more invasive procedures.
The company estimates that roughly 3 million men are prescribed BPH drugs each year in the U.S., but many experience side effects like sexual dysfunction that diminishes their quality of life.
According to Sophiris, topsalysin could provide long-term relief of BPH symptoms with no quality-of-life impairments. In addition, Sophiris says the drug shows promise as a potential treatment for low-grade, localized prostate cancer, based on a preliminary review of biopsy data from the first seven patients in an early Phase 2 proof-of-concept study.
Topsalysin is a recombinant form of proaerolysin, a biologic that converts to the toxin aerolysin. Sophiris genetically modified proaerolysin so the toxin can be activated by only one enzyme—the prostate-specific antigen (PSA), which is found only on the surface of prostate cells and nowhere else in the body. The drug is injected into the prostate near the urethra, where PSA activates the toxin, causing nearby prostate cells to rupture and disintegrate—thus alleviating the symptoms of BPH.
“We are not aware of any other drugs in development that use the same mechanism of action,” Woods says.
In the clinical study, which involved 479 patients in the United States and five other countries, patients who got a
