Background	6 Months Ended
Jun. 30, 2017
Background
Background	1.Background AveXis, Inc. was formed on March 8, 2010 in the state of Delaware as Biolife Cell Bank, LLC. In January 2012, the Company converted from a limited liability company to a corporation, Biolife Cell Bank, Inc. In January 2014, the Company amended and restated its Certificate of Incorporation to change its name to AveXis, Inc. ("AveXis" or "the Company"). The Company is a clinical-stage gene therapy company dedicated to developing and commercializing gene therapy treatments for patients suffering from rare and life-threatening neurological genetic diseases. The Company's initial product candidate, AVXS-101, is a gene therapy product candidate currently in a Phase 1 clinical trial for the treatment of spinal muscular atrophy (“SMA”), Type 1, the leading genetic cause of infant mortality. Initial Public Offering On February 10, 2016, the Company completed an initial public offering (“IPO”), which resulted in the issuance and sale of 4,750,000 shares of its common stock at a public offering price of $20.00 per share, resulting in net proceeds of approximately $88.4 million after deducting underwriting discounts. Upon the closing of the IPO, the 3,278,938 shares of Class B-1 preferred stock, 326,557 shares of Class B-2 preferred stock, 2,365,020 shares of Class C preferred stock and 3,105,000 of Class D preferred stock were automatically converted into shares of the Company’s common stock. On March 3, 2016, the underwriters of the Company’s IPO exercised their over-allotment option to purchase an additional 527,941 shares of the Company’s common stock at the initial public offering price of $20.00 per share, less underwriting discounts and commissions, resulting in additional net proceeds of approximately $9.8 million. September 2016 Underwritten Public Offering On September 13, 2016, the Company completed an underwritten public offering of 4,887,500 shares of its common stock, 4,597,645 shares of which were issued and sold by the Company, including the exercise in full by the underwriters of their option to purchase 637,500 shares from the Company, and 289,855 shares of which were sold by PBM Capital Investments, LLC ("PBM"), an existing stockholder of the Company, each at a public offering price of $34.50 per share. After deducting the underwriting discounts and commissions, the net proceeds to the Company were approximately $149.1 million. The Company did not receive proceeds from the sale of the common stock by PBM.

1.Background

AveXis, Inc. was formed on March 8, 2010 in the state of Delaware as Biolife Cell Bank, LLC. In January 2012, the Company converted from a limited liability company to a corporation, Biolife Cell Bank, Inc. In January 2014, the Company amended and restated its Certificate of Incorporation to change its name to AveXis, Inc. ("AveXis" or "the Company").

The Company is a clinical-stage gene therapy company dedicated to developing and commercializing gene therapy treatments for patients suffering from rare and life-threatening neurological genetic diseases. The Company's initial product candidate, AVXS-101, is a gene therapy product candidate currently in a Phase 1 clinical trial for the treatment of spinal muscular atrophy (“SMA”), Type 1, the leading genetic cause of infant mortality.

Initial Public Offering

On February 10, 2016, the Company completed an initial public offering (“IPO”), which resulted in the issuance and sale of 4,750,000 shares of its common stock at a public offering price of $20.00 per share, resulting in net proceeds of approximately $88.4 million after deducting underwriting discounts. Upon the closing of the IPO, the 3,278,938 shares of Class B-1 preferred stock, 326,557 shares of Class B-2 preferred stock, 2,365,020 shares of Class C preferred stock and 3,105,000 of Class D preferred stock were automatically converted into shares of the Company’s common stock.

On March 3, 2016, the underwriters of the Company’s IPO exercised their over-allotment option to purchase an additional 527,941 shares of the Company’s common stock at the initial public offering price of $20.00 per share, less underwriting discounts and commissions, resulting in additional net proceeds of approximately $9.8 million.

September 2016 Underwritten Public Offering

On September 13, 2016, the Company completed an underwritten public offering of 4,887,500 shares of its common stock, 4,597,645 shares of which were issued and sold by the Company, including the exercise in full by the underwriters of their option to purchase 637,500 shares from the Company, and 289,855 shares of which were sold by PBM Capital Investments, LLC ("PBM"), an existing stockholder of the Company, each at a public offering price of $34.50 per share. After deducting the underwriting discounts and commissions, the net proceeds to the Company were approximately $149.1 million. The Company did not receive proceeds from the sale of the common stock by PBM.