Income Taxes. For the six months ended December 31, 2021 and 2020, we did not recognize any income tax benefit due to our net losses, and our determination that a valuation allowance was required for all of our deferred tax assets.
Liquidity and Capital Resources
We have incurred cumulative net losses of $188.6 million since our inception, and as a clinical stage company we have not generated any revenue to date.
As discussed above under the caption Recent Developments, in October and November 2021 we completed the Underwritten Offering for net proceeds of $47.3 million and the Registered Direct Offering for proceeds of $5.0 million, resulting in total net proceeds of approximately $52.3 million. As of December 31, 2021, we had unrestricted cash and cash equivalents totaling approximately $77.4 million, and working capital was approximately $71.7 million.
In December 2020, we entered into the Equity Distribution Agreement (the “EDA”) with Oppenheimer & Co. Inc. as sales agent that provides for an “at the market offering” for the sale of up to $50.0 million in shares of the Company (“Placement Shares”). For the six months ended December 31, 2021, we sold 138,388 Placement Shares for which aggregate net proceeds of approximately $1.5 million were received. Accordingly, we may sell up to an additional $48.5 million under the EDA. For additional information about the EDA, please refer to Note 6 to the financial statements included in Part I, Item 1 of this Report.
In August 2021, we entered into a purchase agreement (the “Purchase Agreement”) with Lincoln Park Capital Fund, LLC (“LPC”), which provides that we may sell to LPC up to an aggregate of $20.0 million of shares of our common stock (the “Purchase Shares”). The aggregate number of shares that we can sell to LPC under the Purchase Agreement may not exceed 1,669,620 shares of common stock, subject to certain exceptions set forth in the Purchase Agreement. For the six months ended December 31, 2021, LPC purchased 115,708 Purchase Shares and we received net proceeds of $1.2 million. Subject to the terms and conditions of the Purchase Agreement, LPC is obligated to purchase up to a maximum of $18.8 million under the Purchase Agreement as of December 31, 2021. For additional information about the Purchase Agreement, please refer to Note 6 to the financial statements included in Part I, Item 1 of this Report.
In April 2021, we entered into a $30.0 million Loan and Security Agreement (the “Loan Agreement”) with SLR Investment Corp. and certain other lenders (the “Lenders”). The Lenders agreed to loan up to $30.0 million in three tranches consisting of (i) a $15.0 million term A loan that was funded on April 14, 2021, (ii) a $7.5 million term B loan to be funded upon request by us no later than January 25, 2022, and (iii) a $7.5 million term C loan to be funded upon request by us no later than September 25, 2022. Funding of the term B and term C loans was subject to our ability to obtain prescribed amounts of equity or subordinated debt financing and the achievement of certain clinical milestones related to RZ358 and RZ402. We did not achieve the initial clinical milestones to qualify for funding of the term B and term C loans. The term A loan has a maturity date of April 1, 2026.
Outstanding borrowings bear interest at a floating rate equal to (a) 8.75% per annum plus (b) the greater of (i) the rate per annum published by the Intercontinental Exchange Benchmark Administration Ltd. (“IEBA”) for a term of one month and (ii) 0.12% per annum. For the period from April 14, 2021 through December 31, 2021, the IEBA rate for a term of one month was approximately 0.12% per annum. Therefore, the contractual rate was 8.87% as of December 31, 2021 and June 30, 2021. We are permitted to make interest-only payments on the term A loan at least through May 1, 2023.
As a condition of the Loan Agreement, our cash and cash equivalents became subject to a blocked account control agreement (“BACA”) in favor of the Lenders whereby a cash balance of at least $5.0 million was required beginning on December 31, 2021. In the event of a default under the Loan Agreement, the BACA would enable the Lenders to prevent the release of funds from our cash accounts until the default is cured or waived. For additional information about the Loan Agreement, please refer to Note 5 to the financial statements included in Part I, Item 1 of this Report.
As discussed in Note 4 to the financial statements included in Part I, Item 1 of this Report, we are subject to license agreements that provide for future contractual payments upon achievement of various milestone events. Pursuant to the Xoma Agreement, the next milestone includes a $2.0 million payment upon dosing of the last patient in the Company’s ongoing Phase 2b clinical trial for RZ358. Dosing of the last patient in the Phase 2b study occurred in January 2022. Additionally, pursuant to the ActiveSite Agreement, the next milestone will consist of a $3.0 million payment upon dosing of the first patient in a Phase 2 clinical trial for RZ402.