7.    Subsequent Events

In August 2019, we entered into a Securities Purchase Agreement (the “Purchase Agreement”) with a single accredited institutional investor (the “Purchaser”) pursuant to which we issued 1,480,000 shares of our common stock and pre-funded warrants to purchase 1,372,314 shares of our common stock with an exercise price of $0.01 per share (the “Pre-funded Warrants") in a registered direct offering and warrants to purchase 2,852,314 shares of our common stock with an exercise price of $1.07 per share (the “Placement Warrants") in a concurrent private placement. The Pre-Funded Warrants were issued in lieu of common stock in order to ensure the Purchaser did not exceed certain beneficial ownership limitations. The Placement Warrants will be exercisable commencing six months from the date of issuance and will expire five years following the initial exercise date.

The terms of the Purchase Agreement include certain restrictions on our future stock offerings and granted to the Purchaser a participation right in future financings. We received net proceeds of approximately $1.8 million, after deduction of underwriting fees and other offering expenses.