Kura Oncology, Inc. 10-Q

ITEM 1. FINANCIAL STATEMENTS KURA ONCOLOGY, INC. Condensed Balance Sheets (In thousands, except par value data) June 30, 2021 December 31, 2020 (Unaudited) Assets Current assets: Cash and cash equivalents $ 38,974 $ 325,493 Short-term investments 528,520 307,827 Prepaid expenses and other current assets 6,138 3,972 Total current assets 573,632 637,292 Property and equipment, net 2,300 2,021 Restricted cash 210 210 Operating lease right-of-use assets 5,443 6,334 Other long-term assets 3,306 1,355 Total assets $ 584,891 $ 647,212 Liabilities and Stockholders' Equity Current liabilities: Accounts payable and accrued expenses $ 21,290 $ 23,024 Current portion of long-term debt — 3,000 Total current liabilities 21,290 26,024 Long-term debt — 4,250 Long-term operating lease liabilities 4,755 5,638 Other long-term liabilities 295 395 Total liabilities 26,340 36,307 Stockholders' equity: Preferred stock, $ 0.0001 par value; 10,000 shares authorized; no shares issued and outstanding — — Common stock, $ 0.0001 par value; 200,000 shares authorized; 66,296 and 66,194 shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively 7 7 Additional paid-in capital 925,796 913,354 Accumulated other comprehensive income (loss) ( 393 ) 46 Accumulated deficit ( 366,859 ) ( 302,502 ) Total stockholders' equity 558,551 610,905 Total liabilities and stockholders' equity $ 584,891 $ 647,212 See accompanying notes to unaudited condensed financial statements. 1 KURA ONCOLOGY, INC. Condensed Statements of Operations and Comprehensive Loss (In thousands, except per share data) (Unaudited) Three Months Ended Six Months Ended June 30, June 30, 2021 2020 2021 2020 Operating Expenses: Research and development (includes related party amounts of nil and $ 63 for the three months ended June 30, 2021 and 2020, respectively, and nil and $ 195 for the six months ended June 30, 2021 and 2020, respectively) $ 21,074 $ 13,697 $ 41,398 $ 26,272 General and administrative (includes related party amounts of nil and $ 76 for the three months ended June 30, 2021 and 2020, respectively, and nil and $ 187 for the six months ended June 30, 2021 and 2020, respectively) 12,573 7,476 23,145 15,101 Total operating expenses 33,647 21,173 64,543 41,373 Other Income (Expense): Interest and other income, net 290 830 600 1,964 Interest expense ( 306 ) ( 144 ) ( 414 ) ( 288 ) Total other income (expense) ( 16 ) 686 186 1,676 Net Loss $ ( 33,663 ) $ ( 20,487 ) $ ( 64,357 ) $ ( 39,697 ) Net loss per share, basic and diluted $ ( 0.51 ) $ ( 0.40 ) $ ( 0.97 ) $ ( 0.82 ) Weighted average number of shares used in computing net loss per share, basic and diluted 66,282 51,633 66,250 48,522 Comprehensive Loss: Net loss $ ( 33,663 ) $ ( 20,487 ) $ ( 64,357 ) $ ( 39,697 ) Other comprehensive income (loss): Unrealized gain (loss) on marketable securities and foreign currency ( 311 ) ( 4 ) ( 439 ) 226 Comprehensive Loss $ ( 33,974 ) $ ( 20,491 ) $ ( 64,796 ) $ ( 39,471 ) See accompanying notes to unaudited condensed financial statements. 2 KURA ONCOLOGY, INC. Condensed Statements of Stockholders’ Equity (In thousands) (Unaudited) Accumulated Additional Other Total Common Stock Paid-In Comprehensive Accumulated Stockholders' Shares Par Value Capital Income (Loss) Deficit Equity Balance at December 31, 2020 66,194 $ 7 $ 913,354 $ 46 $ ( 302,502 ) $ 610,905 Share-based compensation expense — — 11,068 — — 11,068 Issuance of common stock from exercises of options and employee stock purchase plan 102 — 1,374 — — 1,374 Other comprehensive loss — — — ( 439 ) — ( 439 ) Net loss — — — — ( 64,357 ) ( 64,357 ) Balance at June 30, 2021 66,296 $ 7 $ 925,796 $ ( 393 ) $ ( 366,859 ) $ 558,551 Accumulated Additional Other Total Common Stock Paid-In Comprehensive Accumulated Stockholders' Shares Par Value Capital Income (Loss) Deficit Equity Balance at March 31, 2021 66,263 $ 7 $ 919,258 $ ( 82 ) $ ( 333,196 ) $ 585,987 Share-based compensation expense — — 5,993 — — 5,993 Issuance of common stock from exercises of options and employee stock purchase plan 33 — 545 — — 545 Other comprehensive loss — — — ( 311 ) — ( 311 ) Net loss — — — — ( 33,663 ) ( 33,663 ) Balance at June 30, 2021 66,296 $ 7 $ 925,796 $ ( 393 ) $ ( 366,859 ) $ 558,551 See accompanying notes to unaudited condensed financial statements. 3 KURA ONCOLOGY, INC. Condensed Statements of Stockholders’ Equity (In thousands) (Unaudited) Accumulated Additional Other Total Common Stock Paid-In Comprehensive Accumulated Stockholders' Shares Par Value Capital Income (Loss) Deficit Equity Balance at December 31, 2019 45,384 $ 5 $ 431,322 $ 331 $ ( 212,877 ) $ 218,781 Issuance of common stock, net of offering costs 10,465 1 134,923 — — 134,924 Share-based compensation expense — — 5,705 — — 5,705 Issuance of common stock from exercises of options and employee stock purchase plan 365 — 2,435 — — 2,435 Other comprehensive income — — — 226 — 226 Net loss — — — — ( 39,697 ) ( 39,697 ) Balance at June 30, 2020 56,214 $ 6 $ 574,385 $ 557 $ ( 252,574 ) $ 322,374 Accumulated Additional Other Total Common Stock Paid-In Comprehensive Accumulated Stockholders' Shares Par Value Capital Income (Loss) Deficit Equity Balance at March 31, 2020 45,430 $ 5 $ 434,722 $ 561 $ ( 232,087 ) $ 203,201 Issuance of common stock, net of offering costs 10,465 1 134,923 — — 134,924 Share-based compensation expense — — 2,552 — — 2,552 Issuance of common stock from exercises of options and employee stock purchase plan 319 — 2,188 — — 2,188 Other comprehensive loss — — — ( 4 ) — ( 4 ) Net loss — — — — ( 20,487 ) ( 20,487 ) Balance at June 30, 2020 56,214 $ 6 $ 574,385 $ 557 $ ( 252,574 ) $ 322,374 See accompanying notes to unaudited condensed financial statements. 4 KURA ONCOLOGY, INC. Condensed Statements of Cash Flows (In thousands) (Unaudited) Six Months Ended June 30, 2021 2020 Operating Activities Net loss $ ( 64,357 ) $ ( 39,697 ) Adjustments to reconcile net loss to net cash used in operating activities: Share-based compensation expense 11,068 5,705 Non-cash interest expense 399 — Loss on extinguishment of debt 212 — Depreciation expense 232 12 Amortization of premium and accretion of discounts on marketable securities, net 1,987 ( 134 ) Changes in operating assets and liabilities: Prepaid expenses and other current assets ( 2,166 ) ( 367 ) Other long-term assets ( 1,178 ) 533 Accounts payable and accrued expenses ( 2,688 ) ( 537 ) Other long-term liabilities ( 100 ) ( 71 ) Net cash used in operating activities ( 56,591 ) ( 34,556 ) Investing Activities Purchases of marketable securities ( 353,088 ) ( 96,818 ) Maturities of marketable securities 129,969 103,823 Purchases of property and equipment ( 322 ) ( 1,231 ) Net cash (used in) provided by investing activities ( 223,441 ) 5,774 Financing Activities Repayment of long-term debt ( 7,250 ) — Payment of fees related to extinguishment of debt ( 611 ) — Proceeds from exercises of stock options and purchases under employee stock purchase plan 1,374 2,435 Proceeds from issuance of common stock, net — 135,180 Net cash (used in) provided by financing activities ( 6,487 ) 137,615 Net (decrease) increase in cash, cash equivalents and restricted cash ( 286,519 ) 108,833 Cash, cash equivalents and restricted cash at beginning of period 325,703 26,135 Cash, cash equivalents and restricted cash at end of period $ 39,184 $ 134,968 See accompanying notes to unaudited condensed financial statements. 5 KURA ONCOLOGY, INC. Notes to Unaudited Condensed Financial Statements 1. Organization and Basis of Presentation The Company Kura Oncology, Inc. is a clinical-stage biopharmaceutical company committed to realizing the promise of precision medicines for the treatment of cancer. Our pipeline consists of small molecule product candidates that target cancer signaling pathways where there is a strong scientific and clinical rationale to improve outcomes, and we intend to pair them with molecular or cellular diagnostics to identify those patients most likely to respond to treatment. We plan to advance our product candidates through a combination of internal development and strategic partnerships while maintaining significant development and commercial rights. References in these Notes to Unaudited Condensed Financial Statements to the “Company,” “we,” “our” or “us,” refer to Kura Oncology, Inc. Basis of Presentation The accompanying unaudited condensed financial statements should be read in conjunction with the audited financial statements and notes thereto in our Annual Report on Form 10-K for the fiscal year ended December 31, 2020, as filed with the Securities and Exchange Commission on February 24, 2021, from which we derived our balance sheet as of December 31, 2020. The accompanying unaudited condensed financial statements have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP, for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, since they are interim statements, the accompanying unaudited condensed financial statements do not include all of the information and notes required by GAAP for complete financial statements. The accompanying unaudited condensed financial statements reflect all adjustments, consisting of normal recurring adjustments, that are, in the opinion of our management, necessary to a fair statement of the results for the interim periods presented. Interim results are not necessarily indicative of results for a full year. The preparation of the unaudited condensed financial statements in accordance with GAAP requires our management to make estimates and assumptions that affect the amounts reported on our unaudited condensed financial statements and accompanying notes. The amounts reported could differ under different estimates and assumptions. On an ongoing basis, we evaluate our estimates and judgments, which are based on historical and anticipated results and trends and on various other assumptions that management believes to be reasonable under the circumstances. Though the impact of the COVID-19 pandemic to our business and operating results presents additional uncertainty, we continue to use the best information available to inform our critical accounting estimates. By their nature, estimates are subject to an inherent degree of uncertainty and, as such, actual results may differ from management’s estimates. The extent to which the COVID-19 pandemic has impacted and may continue to impact our business will depend on future developments, which are highly uncertain and cannot be predicted with any confidence, such as the duration and severity of the COVID-19 pandemic, steps required or mandated by governments to mitigate the impact of COVID-19 or the effectiveness of actions to prevent, contain and treat COVID-19, particularly in the geographies where we, our third party manufacturers, contract research organizations or current and planned clinical trial sites operate. We cannot presently predict the scope and severity of any potential business disruptions, interruptions or shutdowns. If we or any of the third parties with whom we engage, however, were to experience shutdowns or other business disruptions, our ability to conduct our business in the manner and on the timelines presently planned could be materially and negatively affected, which could have a material adverse impact on our business and our results of operations and financial condition. 6 2. Summary of Significant Accounting Policies Reclassifications Certain prior period balances have been reclassified to conform to the current period presentation. Restricted Cash Under the terms of an office lease entered into in March 2020, we are required to maintain a standby letter of credit during the term of the lease. As of June 30, 2021, restricted cash of $ 0.2 million was pledged as collateral for the letter of credit. The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the unaudited condensed balance sheets that sum to the total of the amounts shown in the unaudited condensed statements of cash flows, in thousands: June 30, 2021 December 31, 2020 June 30, 2020 December 31, 2019 Cash and cash equivalents $ 38,974 $ 325,493 $ 134,758 $ 26,135 Restricted cash 210 210 210 — Total $ 39,184 $ 325,703 $ 134,968 $ 26,135 Allowance for Credit Losses For available-for-sale debt securities in an unrealized loss position, we first assess whether we intend to sell, or it is more likely than not that we will be required to sell, the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through earnings. For available-for-sale debt securities that do not meet the aforementioned criteria, we evaluate whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, we consider the severity of the impairment, any changes in interest rates, changes to the underlying credit ratings and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded in interest income through an allowance account. Any impairment that has not been recorded through an allowance for credit losses is included in other comprehensive income (loss) on the unaudited condensed statements of operations and comprehensive loss. Concentration of Credit Risk Financial instruments that potentially subject us to significant concentrations of credit risk consist primarily of cash, cash equivalents and short-term investments. We maintain deposits in federally insured financial institutions in excess of federally insured limits. We have established guidelines to limit our exposure to credit risk by placing investments with high credit quality financial institutions, diversifying our investment portfolio and placing investments with maturities that maintain safety and liquidity. We periodically review and modify these guidelines to maximize trends in yields and interest rates without compromising safety and liquidity. Net Loss per Share Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share is calculated by dividing the net loss by the weighted-average number of common shares and common stock equivalents outstanding for the period determined using the treasury-stock method. Common stock equivalents outstanding are comprised of stock options, restricted stock units, a warrant and employee stock purchase plan rights and are only included in the calculation of diluted earnings per common share when net income is reported and their effect is dilutive. Because of our net loss for the three and six months ended June 30, 2021 and 2020 , common stock equivalents outstanding at June 30, 2021 and 2020 totaling approximately 7,002,000 and 5,141,000 , respectively, were excluded from the calculation of diluted net loss per common share because their effect was anti-dilutive. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board or other standard setting bodies that we adopt as of the specified effective date. We have evaluated recently issued accounting pronouncements and, based on our preliminary assessment, we do not believe any will have a material impact on our unaudited condensed financial statements or related footnote disclosures. 7 3. Investments We invest in available-for-sale securities consisting of money market funds, corporate debt securities, U.S. Treasury securities, commercial paper, non-U.S. government debt securities, supranational debt securities and U.S. Agency bonds. Available-for-sale securities are classified as part of either cash and cash equivalents or short-term investments on our unaudited condensed balance sheets. The following tables summarize, by major security type, our short-term investments that are measured at fair value on a recurring basis, in thousands: June 30, 2021 Maturities (years) Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents: Money market funds 1 or less $ 37,471 $ — $ — $ 37,471 Short-term investments: Corporate debt securities 3 or less 202,294 33 ( 153 ) 202,174 U.S. Treasury securities 3 or less 160,877 18 ( 112 ) 160,783 Commercial paper 1 or less 133,427 — — 133,427 Non-U.S. government and supranational debt securities 3 or less 23,180 — ( 21 ) 23,159 U.S. Agency bonds 2 or less 8,992 — ( 15 ) 8,977 Total short-term investments 528,770 51 ( 301 ) 528,520 Total $ 566,241 $ 51 $ ( 301 ) $ 565,991 December 31, 2020 Maturities (years) Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash equivalents: Money market funds 1 or less $ 311,239 $ — $ — $ 311,239 Commercial paper 1 or less 5,998 — — 5,998 Total cash equivalents 317,237 — — 317,237 Short-term investments: Corporate debt securities 2 or less 113,020 36 ( 36 ) 113,020 U.S. Treasury securities 1 or less 88,409 50 ( 2 ) 88,457 Commercial paper 1 or less 106,350 — — 106,350 Total short-term investments 307,779 86 ( 38 ) 307,827 Total $ 625,016 $ 86 $ ( 38 ) $ 625,064 Short-term investments are classified as current assets, even though the stated maturity date may be one year or more beyond the current balance sheet date, which reflects management’s intention to use the proceeds from sales of these securities to fund our operations, as necessary. As of June 30, 2021 and December 31, 2020, short-term investments of $ 282.5 million and $ 242.6 million, respectively, had maturities less than one year, and short-term investments of $ 246.0 million and $ 65.2 million, respectively, had maturities between one to three years. We had no realized gains or losses for the three and six months ended June 30, 2021. As of June 30, 2021, 20 available-for-sale debt securities with a fair market value of $ 200.3 million were in gross unrealized loss positions, none of which were in such position for greater than 12 months. We do not intend to sell these available-for-sale debt securities, and it is not more likely than not that we will be required to sell these securities prior to recovery of their amortized cost basis. Based on our review of these available-for-sale debt securities, no ne of the unrealized losses is the result of a credit loss. As such, we have no allowance for credit losses as of June 30, 2021 and December 31, 2020. Unrealized gains and losses that are not credit-related are included in accumulated other comprehensive income (loss). 8 4. Fair Value Measurements As of June 30, 2021 and December 31, 2020, we had cash equivalents and short-term investments measured at fair value on a recurring basis. Available-for-sale marketable securities consisted of U.S. Treasury securities, which are measured at fair value using Level 1 inputs, and corporate debt securities, commercial paper, non-U.S. government debt securities, supranational debt securities and U.S. Agency bonds, which are measured at fair value using Level 2 inputs. We determine the fair value of Level 2 related securities with the aid of valuations provided by third parties using proprietary valuation models and analytical tools. These valuation models and analytical tools use market pricing or prices for similar instruments that are both objective and publicly available, including matrix pricing or reported trades, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids and/or offers. We validate the fair values of Level 2 financial instruments by comparing these fair values to a third-party pricing source. The following tables summarize, by major security type, our cash equivalents and short-term investments that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy, in thousands: June 30, 2021 Total Level 1 Level 2 Cash equivalents: Money market funds $ 37,471 $ 37,471 $ — Short-term investments: Corporate debt securities 202,174 — 202,174 U.S. Treasury securities 160,783 160,783 — Commercial paper 133,427 — 133,427 Non-U.S. government and supranational debt securities 23,159 — 23,159 U.S. Agency bonds 8,977 — 8,977 Total short-term investments 528,520 160,783 367,737 Total $ 565,991 $ 198,254 $ 367,737 December 31, 2020 Total Level 1 Level 2 Cash equivalents: Money market funds $ 311,239 $ 311,239 $ — Commercial paper 5,998 — 5,998 Total cash equivalents 317,237 311,239 5,998 Short-term investments: Corporate debt securities 113,020 — 113,020 U.S. Treasury securities 88,457 88,457 — Commercial paper 106,350 — 106,350 Total short-term investments 307,827 88,457 219,370 Total $ 625,064 $ 399,696 $ 225,368 9 5. Balance Sheet Detail Property and equipment consisted of the following, in thousands: June 30, 2021 December 31, 2020 Leasehold improvements $ 1,278 $ 1,169 Furniture and fixtures 987 862 Computer software and equipment and laboratory equipment 553 276 Property and equipment, gross 2,818 2,307 Less: accumulated depreciation ( 518 ) ( 286 ) Property and equipment, net $ 2,300 $ 2,021 Accounts payable and accrued expenses consisted of the following, in thousands: June 30, 2021 December 31, 2020 Accounts payable $ 2,404 $ 2,753 Accrued clinical trial research and development expenses 3,397 4,080 Accrued other research and development expenses 6,545 5,581 Accrued compensation and benefits 5,303 7,016 Operating lease liability, current portion 1,981 2,089 Other accrued expenses 1,660 1,505 Total accounts payable and accrued expenses $ 21,290 $ 23,024 6. Long-Term Debt In November 2018, we entered into a loan and security agreement with Silicon Valley Bank, or the SVB Loan Agreement, providing for up to $ 20.0 million in a series of term loans. Upon entering into the SVB Loan Agreement, we borrowed $ 7.5 million, or the Term Loan. The Term Loan had a scheduled maturity date of May 1, 2023 . In May 2021, we paid $ 6.6 million to repay all amounts owed under the Term Loan, which included a final payment of $ 0.6 million, representing 7.75 % of the Term Loan which was being accrued through interest expense using the effective interest method, and a prepayment fee of $ 30,000 . In accordance with ASC 470-50, Debt Modifications and Extinguishments , we accounted for the transaction as an extinguishment of debt. Accordingly, we recorded a loss of approximately $ 0.2 million for each of the three and six months ended June 30, 2021, which is included in interest expense on the unaudited condensed statements of operations and comprehensive loss. 7. Leases In January 2020, we entered into an office lease agreement for our corporate offices in San Diego, California. This agreement was originally scheduled to commence in May 2020 but was subsequently amended with an amended commencement date of August 1, 2020 and an extended lease expiration date of November 30, 2025 . We refer to such office lease agreement, as amended, as the San Diego Lease. The San Diego Lease provides for a one -time option to extend for a period of five additional years. The monthly base rent was approximately $ 58,000 for the first year, with such amount increasing by 3.0 % per year over the initial term. In addition, the San Diego Lease is subject to charges for common area maintenance and other costs. The San Diego Lease provided a four-month rent abatement period during the first year and approximately $ 1.0 million in reimbursements for allowable tenant improvements, which effectively reduced the total lease payments owed for the San Diego Lease. For accounting purposes, the lease commencement date was determined to be March 2020 when we had control of the office space. We recorded an operating lease right-of-use, or ROU, asset and operating lease liability of approximately $ 2.2 million on our unaudited condensed balance sheet on the lease commencement date during the quarter ended March 31, 2020. In March 2020, we entered into a lease agreement for office space in Boston, Massachusetts, or the Boston Lease, which commenced on April 1, 2020 and expires on July 31, 2024 . The Boston Lease provides for a one -time option to extend the Boston Lease for a period of five additional years after the expiration of the initial lease term . Under the terms of the Boston Lease, monthly base rent was approximately $ 105,500 for the first year, subject to an annual fixed percentage increase of 2.0 % 10 on April 1 st of each year . In addition, we are obligated to pay for common area maintenance and other costs. Under the terms of the Boston Lease , we are required to maintain a standby letter of credit of approximately $ 0.2 million during the term of the lease. We recorded an operating lease ROU asset and operating lease liability of approximately $ 5.1 million on our unaudited condensed balance sheet on the lease commencement date during the quarter ended June 30, 2020 . In May 2020, we entered into a two-year sublease agreement, or the Sublease, for certain designated lab space in San Diego, California. The Sublease commenced on June 9, 2020 . In May 2021, the Sublease was amended to modify the lease expiration date to August 9, 2021 , with the monthly base rent increased from approximately $ 12,500 to approximately $ 16,000 effective June 2021. We are not obligated to pay for common area maintenance and other costs. We recorded an operating lease ROU asset and operating lease liability of approximately $ 0.3 million on our unaudited condensed balance sheet on the lease commencement date during the quarter ended June 30, 2020. In May 2021, we entered into an operating lease agreement for lab and office space in San Diego, California, or the Morehouse Lease, which is anticipated to commence on August 10, 2021 and expires on August 31, 2025 . Under the terms of the Morehouse Lease, the monthly base rent is approximately $ 24,000 for the first year, subject to an annual fixed percentage increase of 3 % each year. The Morehouse Lease provides approximately $ 106,000 in reimbursements for allowable tenant improvements, which effectively reduce the total lease payments owed for the Morehouse Lease. The property is undergoing renovations for tenant improvements to install certain lab and office space upgrades. We are obligated to pay for common area maintenance and other costs associated with the Morehouse Lease. For accounting purposes, the lease commencement date is estimated to be July 2021 when we expect to have control of the lab and office space. Maturities of lease liabilities as of June 30, 2021 are as follows, in thousands: Year Ending December 31, 2021 (remaining) $ 1,022 2022 2,032 2023 2,080 2024 1,558 2025 722 Total lease payments 7,414 Less: imputed interest ( 678 ) Total operating lease liabilities $ 6,736 As of June 30, 2021 and December 31, 2020, total operating lease ROU assets were $ 5.4 million and $ 6.3 million, respectively. As of June 30, 2021, total operating lease liabilities were $ 6.7 million, of which $ 4.8 million were recorded as long-term lease liabilities. As of December 31, 2020, total operating lease liabilities were $ 7.7 million, of which $ 5.6 million were recorded as long-term lease liabilities. As of June 30, 2021 and December 31, 2020, the weighted-average discount rate was 5.5 %, and the weighted-average remaining lease term was 3.7 years and 4.1 years, respectively. Total cash paid for amounts included in the measurement of operating lease liabilities was $ 1.1 million for the six months ended June 30, 2021 and $ 0.1 million, net of tenant improvement reimbursements, for the six months ended June 30, 2020. There were no ROU assets obtained in exchange for operating lease liabilities for the six months ended June 30, 2021. ROU assets obtained in exchange for operating lease liabilities were $ 7.5 million for the six months ended June 30, 2020. Total operating lease expense was approximately $ 0.5 million and $ 0.6 million for the three months ended June 30, 2021 and 2020, respectively. Total operating lease expense was approximately $ 1.0 million and $ 0.7 million for the six months ended June 30, 2021 and 2020, respectively. We have also entered into short-term operating leases which expired in 2020 that are not recorded on the unaudited condensed balance sheets . Total rent expense for the three months ended June 30, 2021 and 2020 was approximately $ 0.5 million and $ 0.6 million, respectively. 11 Total rent expense for the six months ended June 30, 2021 and 2020 was approximately $ 1.0 million and $ 0.9 million, respectively . 8. Share-Based Compensation The following table summarizes share-based compensation expense for all share-based compensation arrangements, in thousands: Three Months Ended Six Months Ended June 30, June 30, 2021 2020 2021 2020 Research and development $ 1,847 $ 445 $ 3,218 $ 1,615 General and administrative 4,146 2,107 7,850 4,090 Total share-based compensation expense $ 5,993 $ 2,552 $ 11,068 $ 5,705 During 2021, we began issuing restricted stock units, or RSUs. As of June 30, 2021, unrecognized estimated compensation expense related to stock options and RSUs was approximately $ 58.5 million and $ 5.3 million, respectively, which is expected to be recognized over a weighted average period of approximately 2.8 years and 3.6 years, respectively. 12