the offering was 172,500 shares, resulting in net proceeds to us, after underwriting discounts and offering expenses, of $66.1 million. In connection with the filing of the 2018 Shelf Registration, we entered into a sales agreement with Jefferies, pursuant to which we could issue and sell, from time to time, up to an aggregate of $50.0 million of our common stock in an ATM Offering, through Jefferies, as sales agent. Through the first quarter of 2020, we issued an aggregate of 98,913 shares of our common stock under the ATM Offering, resulting in net proceeds to us of $25.6 million. On March 10, 2020, we suspended and terminated the prospectus related to the ATM Offering.
On March 11, 2020, we sold 320,000 shares of our common stock in an underwritten offering pursuant to the 2018 Shelf Registration at a public offering price of $394.50 per share, resulting in net proceeds of $118.2 million, after underwriting discounts, commissions, and offering expenses. In addition, the underwriters of the offering were granted the option for a period of 30 days to purchase up to an additional 48,000 shares of common stock offered in the public offering at the public offering price, less underwriting discounts, commissions and offering expenses. On April 3, 2020, the underwriters exercised their option and purchased an additional 19,588 shares of common stock at $394.50 per share, resulting in net proceeds to us of $7.2 million, after underwriting discounts, commissions, and offering expenses. The total number of shares sold by us in the offering was 339,588, resulting in total net proceeds to us, after underwriting discounts, commissions and offering expenses, of $125.4 million.
Under the 2018 Shelf Registration, which has now expired, we issued an aggregate of 611,000 shares of common stock, including under the ATM Offering, resulting in aggregate gross proceeds to us of $231.7 million.
On May 7, 2020, we filed our shelf registration statement on Form S-3 that was declared effective by the SEC on May 7, 2020, or the 2020 Shelf Registration, under which we may offer and sell up to $350.0 million of a variety of securities including common stock, preferred stock, warrants, depositary shares, debt securities or units during the three-year period that commenced upon the 2020 Shelf Registration becoming effective. In connection with the filing of the 2020 Shelf Registration, we entered into an amended and restated sales agreement with Jefferies, pursuant to which we may issue and sell, from time to time, up to an aggregate of $75.0 million of our common stock under our ATM Offering. Through December 31, 2021, we issued and sold an aggregate of 171,626 shares of our common stock under the ATM Offering, resulting in net proceeds of $61.8 million, which included 2,283 and 113,950 shares of common stock issued and sold during the three and nine months ended September 30, 2021, respectively, resulting in net proceeds of $6.0 million and $40.7 million, respectively. As of September 30, 2022, there was $11.3 million of shares of common stock remaining under the ATM Offering that we may issue and sell in the future and, excluding the shares of common stock that may be offered under our ATM Offering, there was $275.0 million of securities available to be issued under the 2020 Shelf Registration.
On May 4, 2021, we entered into the Loan Agreement with Oxford Finance, in its capacity as lender, or the Lender, and in its capacity as collateral agent, or Agent, pursuant to which a term loan of up to an aggregate principal amount of $125.0 million is available to us, consisting of (i) a tranche A term loan that was disbursed on the closing date of the Loan Agreement in the aggregate principal amount of $80.0 million; (ii) a contingent tranche B term loan in the aggregate principal amount of $20.0 million available to us through June 30, 2023 and within 90 days of our achieving trailing 6-month product revenue equal to or greater than $75.0 million, subject to certain other terms and conditions; and (iii) a contingent tranche C term loan in the aggregate principal amount of $25.0 million available to us through December 31, 2023 and within 90 days of our achieving trailing 6-month product revenue equal to or greater than $100 million, subject to certain other terms and conditions. The term loans bear interest at a floating rate equal to the greater of 30-day LIBOR and 0.11%, plus 7.89%. Certain of the customary negative covenants limit our and certain of our subsidiaries’ ability, among other things, to incur future debt, grant liens, make investments, make acquisitions, distribute dividends, make certain restricted payments and sell assets, subject in each case to certain exceptions. A delisting of our common stock from the Nasdaq Global Select Market after a specified cure period is also an event of default under our Loan Agreement. Under the Loan Amendment entered into in connection with our entry into the Asset Purchase Agreement with Alcon, the Lender and Agent consented to the entry by us into the Asset Purchase Agreement and the sale of the Commercial Business to Alcon and agreed to release its liens on the Commercial Business in consideration for the Prepayment by us at the closing of the Alcon Transaction of an aggregate amount of $40.0 million to the Lender and Agent. The Prepayment, which represented a partial prepayment of principal in the amount of $36.7 million of the $80.0 million principal amount outstanding under the term loan advanced by the Lender under the Loan Agreement, plus a prepayment fee of $0.7 million and a final payment fee of $2.6 million, was paid on July 8, 2022 in