Acasti Pharma Inc. closed its underwritten public offering of 16.6 million common shares in the U.S. with gross proceeds of about US$19.1 million.

The Laval, Quebec-based pharmaceutical company said underwriters fully exercised their overallotment option to buy an additional 2,490,000 common shares.

Shares in the offering were priced at US$1 apiece.

Acasti Pharma will use the proceeds to fund its late-stage cardiovascular drug trial, named Trilogy, to advance partnering discussions and for working capital and general corporate purposes.

The phase 3 study is evaluating the safety and effectiveness of the experimental drug CaPre to treat severe hypertriglyceridemia, a chronic metabolic condition that heightens the risk of pancreatic and heart diseases.

Oppenheimer & Co. Inc. acted as sole book-running manager for the offering, with Aegis Capital Corp. as co-manager.

Acasti Pharma said its concurrent public offering in Canada of C$24 million of common shares at C$1.28 apiece is expected to close on Oct. 22. Underwriters will have an overallotment option to buy up to an additional 15% of the shares offered.