La Jolla-based Sophiris Bio Inc. has closed its initial U.S. public offering. The company issued 13 million shares at $5 apiece for gross proceeds of $65 million.

Sophiris (Nasdaq: SPHS), which is developing a treatment for prostate enlargement, began trading on the Nasdaq on August 16. It closed at $4.15 — about 17 percent lower than the IPO price. On August 23, shares closed at $4.62.

About $28.5 million of the U.S. initial public offering will fund the phase 3 clinical trials for its enlarged prostate treatment drug, and $10.5 million will pay for further clinical development for the drug, according to regulatory filings.

— Meghana Keshavan