San Diego Business Journal

San Diego-based Mast Therapeutics Inc., a clinical-stage biopharmaceutical company, announced the pricing of its underwritten public offering that is expected to raise gross proceeds of approximately $21 million.

The company is offering 30,941,102 Series A units at a purchase price per unit of $0.48. Each Series A unit will consist of one share of common stock and one-half of a warrant. Each whole warrant will be exercisable for one share of common stock at an initial exercise price of $0.75 per share.

In lieu of Series A units that include common stock, the company is also offering 13,081,428 Series B units at a purchase price per unit of $0.47. Series B units are being offered only to those purchasers whose purchase of additional Series A units in the offering would otherwise result in the purchaser beneficially owning more than 4.99 percent of the company's outstanding common stock following the completion of the offering. Each Series B unit will consist of one pre-funded warrant to purchase one share of common stock at an initial exercise price of $0.01 per share and one-half of a warrant. Each whole warrant will be exercisable for one share of common stock at an initial exercise price of $0.75 per share.

The offering is expected to close on or about Nov. 12, subject to customary closing conditions. All of the securities in the offering are being sold by Mast Therapeutics.

Mast (NYSE MKT: MSTX) expects to receive net proceeds from the offering of approximately $20 million, after deducting underwriting discounts and commissions and estimated offering expenses. The company said it intends to use the net proceeds primarily to fund its clinical development programs, including Epic, the company's ongoing Phase 3 study of MST-188 in sickle cell disease, and for working capital and general corporate purposes.

Cowen and Co. LLC is acting as sole book-running manager. Canaccord Genuity Inc. is acting as lead manager and Laidlaw & Co. and Highline Research Advisers are acting as co-managers for the offering.