General and Administrative Expenses. General and administrative expenses increased by
$1.2 million, or 4%, to $28.5 million for the year ended December 31, 2022 from $27.3 million for the year ended December 31, 2021. The increase in general and administrative expenses was primarily due to a $0.8 million
increase in expense related to our commercial capabilities and infrastructure and $0.4 million increase in expenses related to financing activities.
Liquidity and Capital Resources
Sources of
liquidity
We are a clinical-stage biotechnology company with a limited operating history, and due to our significant research and
development expenditures, we have generated operating losses since our inception and have not generated any revenue from the sale of any products. Since our inception and through December 31, 2022, we have funded our operations primarily by
raising an aggregate of $506.2 million of gross proceeds from the sale and issuance of convertible preferred and common equity securities, pre-funded stock warrants, the collection of grant proceeds, and
the licensing of our product rights for the commercialization of pegzilarginase in Europe and several countries in the Middle East.
In
March 2021, we entered into the Immedica Agreement, pursuant to which Immedica licensed the product rights for commercialization of pegzilarginase in the European Economic Area, United Kingdom, Switzerland, Andorra, Monaco, San Marino, Vatican City,
Turkey, Saudi Arabia, United Arab Emirates, Qatar, Kuwait, Bahrain, and Oman. In April 2021, we received an upfront payment of $21.5 million from Immedica. Under the terms of the Immedica Agreement, we are also eligible to receive additional
payments of up to approximately $120.8 million in regulatory and commercial milestone payments, assuming an exchange rate of $1.07 to 1.00. Additionally, we are entitled to receive royalties in the
mid-20 percent range on the net sales of the product in countries included in the Immedica Agreement. In July 2021, the Immedica Agreement was modified to include additional development services, up to
$3.0 million, to support the PEACE Phase 3 trial and BLA package performance obligation.
During the year ended December 31,
2020, we raised $163.3 million of gross proceeds through an underwritten public offering and an at-the-market offering program. We sold 617,692 shares of common
stock and pre-funded warrants to purchase up to 544,413 shares of common stock in an underwritten public offering, or the 2020 Public Offering, for gross proceeds of $138.0 million, resulting in net
proceeds of $129.0 million after deducting underwriting discounts, commissions, and offering costs. Additionally, we sold an aggregate of 129,803 shares of common stock under an
at-the-market offering program, or the 2020 ATM, for gross proceeds of $25.3 million, resulting in net proceeds of $24.6 million, after deducting underwriting
discounts, commissions, and offering costs.
The shares of common stock and pre-funded warrants
sold in the 2020 Public Offering were pursuant to a shelf registration statement on Form S-3, declared effective in February 2019 by the SEC for the potential offering, issuance and sale by us of up to
$200.0 million of our common stock, warrants to purchase common stock, and other security types and subscription rights. The shares of common stock sold under the 2020 ATM were pursuant to an April 2020 sales agreement with JonesTrading
Institutional Services LLC, as sales agent, to issue and sell shares of our common stock for an aggregate offering price of $60.0 million. In February 2022, the shelf registration statement the 2020 ATM was registered under expired and no sales
under this registration statement will occur going forward.
In July 2020, we filed a shelf registration statement on Form S-3, or the 2020 Registration Statement, that was declared effective by the SEC for the potential offering, issuance and sale by us of up to $400.0 million of our common stock, preferred stock, debt securities,
warrants to purchase common stock, preferred stock and debt securities, subscription rights to purchase common stock and units consisting of all or some of these securities.
In May 2022, we sold 430,107 shares of common stock and pre-funded warrants to purchase up to 694,892
shares of common stock in a registered direct offering, or the 2022 RDO, for gross proceeds of $45.0 million, resulting in net proceeds of $42.9 million after deducting placement agent fees and offering costs. The shares of common stock
and pre-funded warrants sold in the 2022 RDO were offered pursuant to the 2020 Registration Statement.
Also in May 2022, we entered into a sales agreement, or the 2022 Sales Agreement, with JonesTrading Institutional Services LLC, as sales
agent, to issue and sell shares of our common stock for an aggregate offering price of $60.0 million under an at-the-market offering program with JonesTrading
Institutional Services LLC, pursuant to the 2020 Registration Statement. As of the date of the filing of this report, $60.0 million of our common stock remained available for sale pursuant to the 2022 Sales Agreement. Any sales of common stock
to be sold under the 2022 Sales Agreement will be made pursuant to the 2020 Registration Statement.