10.  Public Offering of Common Stock

On May 8, 2018, the Company entered into an underwriting agreement with Jefferies LLC and Leerink Partners LLC, as representatives of the several underwriters named therein (collectively, the “Underwriters”), pursuant to which the Company agreed to issue and sell 3,000,000 shares of the Company’s common stock in an underwritten registered public offering at an offering price of $41.00 per share (the “2018 Offering”).  The Company granted the Underwriters a 30-day option to purchase up to an aggregate of 450,000 additional shares of common stock, at the public offering price, less the underwriting discounts and commissions, which was exercised in full on May 9, 2018.

The 2018 Offering closed on May 11, 2018, and the Company received proceeds of approximately $132.7 million from the sale of the shares (including the sale of 450,000 additional shares issued upon exercise of the Underwriters’ overallotment option), after deducting the underwriting discounts and commissions and estimated offering expenses.