Document And Entity Information
Document And Entity Information - USD ($) | 12 Months Ended | ||
Dec. 31, 2023 | Feb. 26, 2024 | Jun. 30, 2023 | |
Document Information [Line Items] | |||
Entity Central Index Key | 0001069530 | ||
Entity Registrant Name | CASSAVA SCIENCES INC | ||
Amendment Flag | false | ||
Current Fiscal Year End Date | --12-31 | ||
Document Fiscal Period Focus | FY | ||
Document Fiscal Year Focus | 2023 | ||
Document Type | 10-K | ||
Document Annual Report | true | ||
Document Period End Date | Dec. 31, 2023 | ||
Document Transition Report | false | ||
Entity File Number | 000-29959 | ||
Entity Incorporation, State or Country Code | DE | ||
Entity Tax Identification Number | 91-1911336 | ||
Entity Address, Address Line One | 6801 N. Capital of Texas Highway, Building 1; Suite 300 | ||
Entity Address, City or Town | Austin | ||
Entity Address, State or Province | TX | ||
Entity Address, Postal Zip Code | 78731 | ||
City Area Code | 512 | ||
Local Phone Number | 501-2444 | ||
Entity Well-known Seasoned Issuer | Yes | ||
Entity Voluntary Filers | No | ||
Entity Current Reporting Status | Yes | ||
Entity Interactive Data Current | Yes | ||
Entity Filer Category | Large Accelerated Filer | ||
Entity Small Business | false | ||
Entity Emerging Growth Company | false | ||
ICFR Auditor Attestation Flag | true | ||
Document Financial Statement Error Correction [Flag] | false | ||
Entity Shell Company | false | ||
Entity Public Float | $ 967,000,000 | ||
Entity Common Stock, Shares Outstanding | 43,225,211 | ||
Auditor Firm ID | 42 | ||
Auditor Name | Ernst & Young LLP | ||
Auditor Location | Austin, Texas | ||
Warrant [Member] | |||
Document Information [Line Items] | |||
Title of 12(b) Security | Warrants, exercisable for shares of Common Stock | ||
Trading Symbol | SAVAW | ||
Security Exchange Name | NASDAQ | ||
Common Stock [Member] | |||
Document Information [Line Items] | |||
Title of 12(b) Security | Common Stock, $0.001 par value | ||
Trading Symbol | SAVA | ||
Security Exchange Name | NASDAQ |
Consolidated Balance Sheets
Consolidated Balance Sheets - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Current assets: | ||
Cash and cash equivalents | $ 121,136 | $ 201,015 |
Prepaid expenses and other current assets | 8,497 | 10,211 |
Total current assets | 129,633 | 211,226 |
Operating lease right-of-use assets | 0 | 122 |
Property and equipment, net | 21,854 | 22,864 |
Intangible assets, net | 176 | 622 |
Total assets | 151,663 | 234,834 |
Current liabilities: | ||
Accounts payable and other accrued expenses | 10,573 | 4,017 |
Accrued development expense | 3,037 | 2,280 |
Accrued compensation and benefits | 200 | 170 |
Operating lease liabilities, current | 0 | 104 |
Other current liabilities | 385 | 492 |
Total current liabilities | 14,195 | 7,063 |
Operating lease liabilities, non-current | 0 | 35 |
Other non-current liabilities | 0 | 197 |
Total liabilities | 14,195 | 7,295 |
Commitments and contingencies (Notes 10, 11 and 12) | ||
Stockholders' equity: | ||
Preferred stock, $0.001 par value; 10,000,000 shares authorized, none issued and outstanding | 0 | 0 |
Common stock, $0.001 par value; 120,000,000 shares authorized; 42,236,919 and 41,735,557 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively | 42 | 42 |
Additional paid-in capital | 518,195 | 511,049 |
Retained Earnings (Accumulated Deficit) | (380,769) | (283,552) |
Total stockholders' equity | 137,468 | 227,539 |
Total liabilities and stockholders' equity | $ 151,663 | $ 234,834 |
Consolidated Balance Sheets (Pa
Consolidated Balance Sheets (Parentheticals) - $ / shares | Dec. 31, 2023 | Dec. 31, 2022 |
Preferred stock, par value (in dollars per share) | $ 0.001 | $ 0.001 |
Preferred stock, shares authorized (in shares) | 10,000,000 | 10,000,000 |
Preferred stock, shares issued (in shares) | 0 | 0 |
Preferred stock, shares outstanding (in shares) | 0 | 0 |
Common stock, par value (in dollars per share) | $ 0.001 | $ 0.001 |
Common stock, shares authorized (in shares) | 120,000,000 | 120,000,000 |
Common stock, shares issued (in shares) | 42,236,919 | 41,735,557 |
Common stock, shares outstanding (in shares) | 42,236,919 | 41,735,557 |
Consolidated Statements of Oper
Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Operating expenses: | |||
Research and development, net of grant reimbursement | $ 89,423 | $ 68,032 | $ 24,813 |
General and administrative | 16,534 | 11,988 | 8,055 |
Total operating expenses | 105,957 | 80,020 | 32,868 |
Operating loss | (105,957) | (80,020) | (32,868) |
Interest income | 7,833 | 2,777 | 49 |
Other income, net | 907 | 997 | 434 |
Net loss | $ (97,217) | $ (76,246) | $ (32,385) |
Net loss per share, basic and diluted (in dollars per share) | $ (2.32) | $ (1.9) | $ (0.82) |
Shares used in computing net loss per share, basic and diluted (in shares) | 41,932 | 40,202 | 39,405 |
Consolidated Statements of Stoc
Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands | Share-Based Payment Arrangement, Employee [Member] Common Stock [Member] | Share-Based Payment Arrangement, Employee [Member] Additional Paid-in Capital [Member] | Share-Based Payment Arrangement, Employee [Member] Retained Earnings [Member] | Share-Based Payment Arrangement, Employee [Member] | Share-Based Payment Arrangement, Nonemployee [Member] Common Stock [Member] | Share-Based Payment Arrangement, Nonemployee [Member] Additional Paid-in Capital [Member] | Share-Based Payment Arrangement, Nonemployee [Member] Retained Earnings [Member] | Share-Based Payment Arrangement, Nonemployee [Member] | Common Stock [Member] | Additional Paid-in Capital [Member] | Retained Earnings [Member] | Total |
Balance (in shares) at Dec. 31, 2020 | 35,237,987 | |||||||||||
Balance at Dec. 31, 2020 | $ 35 | $ 267,086 | $ (174,921) | $ 92,200 | ||||||||
Stock-based compensation for stock options | $ 0 | $ 1,706 | $ 0 | $ 1,706 | $ 0 | $ 53 | $ 0 | $ 53 | ||||
Issuance of common stock pursuant to exercise of stock options (in shares) | 143,153 | |||||||||||
Issuance of common stock pursuant to exercise of stock options | $ 0 | 1,824 | 0 | 1,824 | ||||||||
Issuance of common stock pursuant to exercise of warrants (in shares) | 554,019 | |||||||||||
Issuance of common stock pursuant to exercise of warrants | $ 1 | 691 | 0 | 692 | ||||||||
Common stock issued in conjunction with registered direct offering, net of issuance costs (in shares) | 4,081,633 | |||||||||||
Common stock issued in conjunction with registered direct offering, net of issuance costs | $ 4 | 189,821 | 0 | 189,825 | ||||||||
Net loss | $ 0 | 0 | (32,385) | (32,385) | ||||||||
Balance (in shares) at Dec. 31, 2021 | 40,016,792 | |||||||||||
Balance at Dec. 31, 2021 | $ 40 | 461,181 | (207,306) | 253,915 | ||||||||
Stock-based compensation for stock options | 0 | 1,972 | 0 | 1,972 | 0 | 94 | 0 | 94 | ||||
Issuance of common stock pursuant to exercise of stock options (in shares) | 109,241 | |||||||||||
Issuance of common stock pursuant to exercise of stock options | $ 0 | 475 | 0 | 475 | ||||||||
Common stock issued in conjunction with registered direct offering, net of issuance costs (in shares) | 1,666,667 | |||||||||||
Common stock issued in conjunction with registered direct offering, net of issuance costs | $ 2 | 47,327 | 0 | 47,329 | ||||||||
Net loss | $ 0 | 0 | (76,246) | (76,246) | ||||||||
Expiration of restricted stock Performance Awards (in shares) | (57,143) | |||||||||||
Expiration of restricted stock Performance Awards | $ 0 | 0 | 0 | 0 | ||||||||
Balance (in shares) at Dec. 31, 2022 | 41,735,557 | |||||||||||
Balance at Dec. 31, 2022 | $ 42 | 511,049 | (283,552) | $ 227,539 | ||||||||
Stock-based compensation for stock options | $ 0 | $ 4,493 | $ 0 | $ 4,493 | $ 0 | $ 93 | $ 0 | $ 93 | ||||
Issuance of common stock pursuant to exercise of stock options (in shares) | 501,362 | 602,420 | ||||||||||
Issuance of common stock pursuant to exercise of stock options | $ 0 | 2,560 | 0 | $ 2,560 | ||||||||
Net loss | $ 0 | 0 | (97,217) | (97,217) | ||||||||
Balance (in shares) at Dec. 31, 2023 | 42,236,919 | |||||||||||
Balance at Dec. 31, 2023 | $ 42 | $ 518,195 | $ (380,769) | $ 137,468 |
Consolidated Statements of Cash
Consolidated Statements of Cash Flows - USD ($) | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Cash flows from operating activities: | |||
Net loss | $ (97,217,000) | $ (76,246,000) | $ (32,385,000) |
Adjustments to reconcile net loss to net cash used in operating activities: | |||
Stock-based compensation | 4,586,000 | 2,066,000 | 1,759,000 |
Depreciation | 1,084,000 | 804,000 | 310,000 |
Amortization of intangible assets | 446,000 | 497,000 | 224,000 |
Changes in operating assets and liabilities: | |||
Prepaid and other assets | 1,714,000 | 1,189,000 | (10,956,000) |
Operating lease right-of-use assets and liabilities | (17,000) | (9,000) | 28,000 |
Accounts payable and other accrued expenses | 6,896,000 | (3,449,000) | 6,215,000 |
Accrued development expense | 757,000 | (523,000) | 2,084,000 |
Accrued compensation and benefits | 30,000 | (1,707,000) | 1,794,000 |
Other liabilities | (304,000) | (136,000) | 731,000 |
Net cash used in operating activities | (82,025,000) | (77,514,000) | (30,196,000) |
Cash flows from investing activities: | |||
Purchase of property and equipment | (414,000) | (2,712,000) | (22,214,000) |
Net cash used in investing activities | (414,000) | (2,712,000) | (22,214,000) |
Cash flows from financing activities: | |||
Proceeds from issuance of common stock upon exercise of stock options | 2,560,000 | 475,000 | 1,824,000 |
Proceeds from issuance of common stock upon exercise of 2018 warrants | 0 | 0 | 692,000 |
Proceeds from common stock offering, net of issuance costs | 0 | 47,329,000 | 189,825,000 |
Net cash provided by financing activities | 2,560,000 | 47,804,000 | 192,341,000 |
Net (decrease) increase in cash and cash equivalents | (79,879,000) | (32,422,000) | 139,931,000 |
Cash and cash equivalents at beginning of period | 201,015,000 | 233,437,000 | 93,506,000 |
Cash and cash equivalents at end of period | 121,136,000 | 201,015,000 | 233,437,000 |
Non-cash investing activities | |||
Purchases of property and equipment included in accounts payable | $ 0 | $ 340,000 | $ 0 |
Note 1 - General, Liquidity and
Note 1 - General, Liquidity and Basis of Presentation | 12 Months Ended |
Dec. 31, 2023 | |
Notes to Financial Statements | |
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] | 1. General, Liquidity and Basis of Presentation Cassava Sciences, Inc. and its wholly-owned subsidiary (collectively referred to as the “Company”) discovers and develops proprietary pharmaceutical product candidates that may Basis of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary. All intercompany transactions have been eliminated in consolidation. Liquidity The Company has incurred significant net losses and negative cash flows since inception, and as a result has an accumulated deficit of $380.8 million at December 31, 2023. may no 12 |
Note 2 - Summary of Significant
Note 2 - Summary of Significant Accounting Policies | 12 Months Ended |
Dec. 31, 2023 | |
Notes to Financial Statements | |
Significant Accounting Policies [Text Block] | 2. Use of Estimates The Company makes estimates and assumptions in preparing its consolidated financial statements in conformity with accounting principles generally accepted in the United States. These estimates and assumptions affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amount of revenue earned and expenses incurred during the reporting period. The Company evaluates its estimates on an ongoing basis, including those estimates related to clinical trials and manufacturing agreements. Actual results could differ from these estimates and assumptions. Proceeds from Grants During 2023, no 2022, 2021, Cash and Cash Equivalents and Concentration of Credit Risk The Company invests in cash and cash equivalents. The Company considers highly-liquid financial instruments with original maturities of three one Fair Value Measurements The Company recognizes financial instruments in accordance with the authoritative guidance on fair value measurements and disclosures for financial assets and liabilities. This guidance defines fair value, establishes a framework for measuring fair value in accordance with GAAP, and expands disclosures about fair value measurements. The guidance also establishes a three ● Level 1 ● Level 2 third not 2 ● Level 3 no not 3 If a financial instrument uses inputs that fall in different levels of the hierarchy, the instrument will be categorized based upon the lowest level of input that is significant to the fair value calculation. The fair value of cash and cash equivalents was based on Level 1 December 31, 2023 2022. Business Segments The Company reports segment information based on how it internally evaluates the operating performance of its business units, or segments. The Company’s operations are confined to one business segment: the development of novel drugs and diagnostics. Stock-based Compensation The Company recognizes non-cash expense for the fair value of all stock options and other share-based awards. The Company uses the Black-Scholes option valuation model (“Black-Scholes”) to calculate the fair value of stock options, using the single-option award approach and straight-line attribution method. This model requires the input of subjective assumptions including expected stock price volatility, expected life and estimated forfeitures of each award. These assumptions consist of estimates of future market conditions, which are inherently uncertain, and therefore, are subject to management’s judgment. For all options granted, it recognizes the resulting fair value as expense on a straight-line basis over the vesting period of each respective stock option, generally three four The Company has granted share-based awards that vest upon achievement of certain performance criteria (“Performance Awards”). The Company multiplies the number of Performance Awards by the fair value of its common stock on the date of grant to calculate the fair value of each award. It estimates an implicit service period for achieving performance criteria for each award. The Company recognizes the resulting fair value as expense over the implicit service period when it concludes that achieving the performance criteria is probable. It periodically reviews and updates as appropriate its estimates of implicit service periods and conclusions on achieving the performance criteria. Performance Awards vest and common stock is issued upon achievement of the performance criteria. Net Loss per Share The Company computes basic net loss per share on the basis of the weighted-average number of common shares outstanding for the reporting period. Diluted net loss per share is computed on the basis of the weighted-average number of common shares outstanding plus potential dilutive common shares outstanding using the treasury-stock method. Potential dilutive common shares consist of outstanding common stock options and warrants. There is no Years ended December 31, 2023 2022 2021 Numerator: Net loss $ (97,217 ) $ (76,246 ) $ (32,385 ) Denominator: Shares used in computing net loss per share, basic and diluted 41,932 40,202 39,405 Net loss per share, basic and diluted $ (2.32 ) $ (1.90 ) $ (0.82 ) Dilutive common stock options excluded from net loss per share, diluted 2,123 2,055 2,211 The Company excluded common stock options and warrants outstanding, along with 57,143 restricted stock awards, from the calculation of net loss per share, diluted, because the effect of including outstanding options would have been anti-dilutive. The 57,143 restricted stock awards expired during the year ended December 31, 2022. Fair Value of Financial Instruments Financial instruments include accounts payable, accrued expenses and other liabilities. The estimated fair value of certain financial instruments may not may Research Contracts, Prepaids and Accruals The Company has entered into various research and development contracts with research institutions and other third not Incentive Bonus Plan In 2020, 2020 718 Stock-based Compensation 11 Leases The Company recognizes assets and liabilities that arise from leases. For operating leases, the Company is required to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments during the lease term, in the consolidated balance sheets. The Company elected the short-term lease recognition exemption for all leases that qualify. This means, for those leases that qualify, the Company does not not Property and equipment Property and equipment is recorded at cost, net of accumulated depreciation. Depreciation is recorded using the straight-line method over the estimated useful lives of the assets. Owned buildings and related improvements have estimated useful lives of 39 years and approximately 10 years, respectively. Tenant improvements related to leased space are amortized using the straight-line method over the useful lives of the improvements or the remaining term of the corresponding leases, whichever is shorter. The remaining term of the corresponding leases is approximately 0.4 years. Property and equipment are reviewed for impairment when events or changes in circumstances indicate the carrying amount of an asset may not Intangible assets Acquired intangible assets are recorded at fair value at the date of acquisition and primarily consist of lease-in-place agreements and leasing commissions. Intangible assets are amortized over the estimated life of the lease-in-place agreements, which approximates 0.3 years at December 31, 2023. Intangible assets are reviewed for impairment on an annual basis, and when there is reason to believe that their values have been diminished or impaired. If intangible assets are considered to be impaired, an impairment loss is recognized. Income Taxes The Company accounts for income taxes under the asset and liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax balances are adjusted to reflect tax rates based on currently enacted tax laws, which will be in effect in the years in which the temporary differences are expected to reverse. The Company has accumulated significant deferred tax assets that reflect the tax effects of net operating loss and tax credit carryovers and temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Realization of certain deferred tax assets is dependent upon future earnings. The Company is uncertain about the timing and amount of any future earnings. Accordingly, the Company offsets these deferred tax assets with a valuation allowance. The Company accounts for uncertain tax positions in accordance with ASC 740, not |
Note 3 - Prepaid and Other Curr
Note 3 - Prepaid and Other Current Assets | 12 Months Ended |
Dec. 31, 2023 | |
Notes to Financial Statements | |
Prepaid Expenses and Other Current Assets [Text Bock] | 3. Prepaid and other current assets at December 31, 2023 2022 December 31, 2023 2022 Prepaid insurance $ 759 $ 874 Contract research organization and other deposits 6,489 9,177 Interest receivable 962 — Other 287 160 Total prepaid expenses and other current assets $ 8,497 $ 10,211 Contract research organization and other deposits represent cash payments made to vendors in excess of expenses incurred. |
Note 4 - Real Property and Othe
Note 4 - Real Property and Other Income, Expense | 12 Months Ended |
Dec. 31, 2023 | |
Notes to Financial Statements | |
Real Estate Owned [Text Block] | 4. The Company owns a two December 31, 2023, third The Company records the net income from building operations and leases as other income, net, as leasing is not not Years ended December 31, 2023 2022 2021 Lease revenue $ 2,283 $ 2,459 $ 911 Property operating expenses (1,376 ) (1,462 ) (477 ) Other income, net $ 907 $ 997 $ 434 The Company had accrued property taxes related to the building totaling $338,000 and $433,000 at December 31, 2023 2022, |
Note 5 - Property and Equipment
Note 5 - Property and Equipment | 12 Months Ended |
Dec. 31, 2023 | |
Notes to Financial Statements | |
Property, Plant and Equipment Disclosure [Text Block] | 5. The components of property and equipment, net, as of December 31, 2023 2022 December 31, 2023 2022 Land $ 3,734 $ 3,734 Buildings 15,980 15,980 Site improvements 494 470 Tenant improvements 3,062 3,016 Furniture and equipment 868 851 Construction in progress — 13 Gross property and equipment $ 24,138 $ 24,064 Accumulated depreciation (2,284 ) (1,200 ) Property and equipment, net $ 21,854 $ 22,864 Depreciation expense for property and equipment was $1,084,000, $804,000 and $310,000 for the years ended December 31, 2023, 2022 2021, |
Note 6 - Intangible Assets
Note 6 - Intangible Assets | 12 Months Ended |
Dec. 31, 2023 | |
Notes to Financial Statements | |
Intangible Assets Disclosure [Text Block] | 6. The components of intangible assets, net, as of December 31, 2023 2022 December 31, 2023 2022 Lease-in-place agreements $ 1,053 $ 1,053 Leasing commissions and other 293 290 Gross intangible assets $ 1,346 $ 1,343 Accumulated amortization (1,170 ) (721 ) Intangible assets, net $ 176 $ 622 Amortization expense for intangible assets was $446,000, $497,000 and $224,000 for the years ended December 31, 2023, 2022 2021, Amortization expense for finite-lived intangible assets is expected to be as follows (in thousands): For the year ending December 31, 2024 172 2025 4 Total amortization $ 176 |
Note 7 - Stockholders' Equity a
Note 7 - Stockholders' Equity and Stock-based Compensation Expense | 12 Months Ended |
Dec. 31, 2023 | |
Notes to Financial Statements | |
Shareholders' Equity and Share-Based Payments [Text Block] | 7. Preferred Stock The Company’s Board of Directors (the “Board”) has the authority to issue preferred stock in one 2022 On November 22, 2022, 2021 On February 12, 2021, At the Market (ATM) Common Stock Issuance On May 1, 2023, May 1, 2023 not There were no common stock sales under the ATM during the year ended December 31, 2023. In March 2020, “2020 May 5, 2020. 2020 April 26, 2023, May 1, 2023. no 2020 2008 Under the Company’s 2008 2008 2008 December 2017. ten 2018 The Company’s Board or a designated Committee of the Board is responsible for administration of the Company’s 2018 2018 2018 2018 ten 2018 May 5, 2022, 2018 When stock options or performance awards are exercised net of the exercise price and taxes, the number of shares of stock issued is reduced by the number of shares equal to the amount of taxes owed by the award recipient and that number of shares are cancelled. The Company may Stock Options The following summarizes information about stock option activity during 2023: Weighted Average Weighted Average Number of Weighted Average Remaining Contractual Aggregate Intrinsic Value Options Exercise Price Term in Years in Millions Outstanding as of December 31, 2022 2,529,448 $ 12.13 3.94 $ 49.60 Options granted 1,162,000 18.91 Options exercised (602,420 ) 8.38 Options forfeited/canceled (49,999 ) 32.59 Outstanding as of December 31, 2023 3,039,029 — — $ — Vested and expected to vest at December 31, 2023 3,039,029 15.13 6.21 $ 30.28 Exercisable at December 31, 2023 1,836,174 $ 11.09 3.98 $ 26.18 Of the stock options exercised during the year ended December 31, 2023, no The following summarizes information about stock options at December 31, 2023 Options outstanding Options exercisable Weighted average Weighted Weighted Number of remaining average Number of average Range of exercise prices outstanding contractual exercise vested exercise From To options life (in years) price options price $ 0.95 $ 3.24 804,834 4.8 $ 2.17 804,834 $ 2.17 $ 4.09 $ 13.02 656,230 2.9 $ 8.33 647,167 $ 8.34 $ 14.21 $ 16.94 62,634 1.9 $ 16.00 62,634 $ 16.00 $ 17.54 $ 17.54 800,000 9.8 $ 17.54 44,442 $ 17.54 $ 21.11 $ 77.00 715,331 7.2 $ 33.20 277,097 $ 41.29 3,039,029 6.2 $ 15.13 1,836,174 $ 11.09 The Company uses Black-Scholes to estimate the fair value of options granted. Black-Scholes considers a number of factors, including the market price of the Company’s common stock. Factors utilized in Black-Scholes to value each stock option granted, and the weighted average fair value of options granted during the years ended December 31, 2023, 2022 2021 2023 2022 2021 Volatility 152% to 155% 151% to 154% 147% to 151% Risk-free interest rates 3.82% to 4.37% 1.98% to 3.69% 1.12% to 1.42% Expected life of option (in years) 7 7 7 Dividend yield zero zero zero Forfeiture rate zero zero zero Weighted average fair value of stock options granted $ 18.21 $ 35.16 $ 65.83 Volatility is based on reviews of the historical volatility of the Company’s common stock. Risk-free interest rates are based on yields of U.S. treasury notes in effect at the date of grant. Expected life of option is based on actual historical option exercises. Dividend yield is zero because the Company does not As of December 31, 2023, Performance Awards The following summarizes information about performance award activity during 2023: Number of Performance Awards Outstanding as of December 31, 2022 7,142 Granted — Vested — Forfeited/canceled — Outstanding as of December 31, 2023 7,142 During the year ended December 31, 2022, not 2008 December 2017, If and when outstanding Performance Awards vest, the Company would recognize $101,000 in stock-based compensation expense. These performance awards expire in 2026. Stock-Based Compensation Expense The following summarizes information about stock-based compensation expense, in thousands: Years ended December 31, 2023 2022 2021 Research and development $ 2,050 $ 1,631 $ 1,302 General and administrative 2,536 435 457 Total stock-based compensation expense $ 4,586 $ 2,066 $ 1,759 |
Note 8 - Employee 401(k) Benefi
Note 8 - Employee 401(k) Benefit Plan | 12 Months Ended |
Dec. 31, 2023 | |
Notes to Financial Statements | |
Compensation and Employee Benefit Plans [Text Block] | 8. 401 The Company has a defined-contribution savings plan under Section 401 first may 401 December 31, 2023, not 401 |
Note 9 - Income Taxes
Note 9 - Income Taxes | 12 Months Ended |
Dec. 31, 2023 | |
Notes to Financial Statements | |
Income Tax Disclosure [Text Block] | 9. The Company did not The reconciliation of the statutory federal income tax rate to the Company’s effective tax rate for periods presented was as follows: Year ended December 31, 2023 2022 2021 Tax at federal statutory rate 21 % 21 % 21 % State tax, net of federal benefit — — — Share-based compensation 0.2 (0.5 ) 1.2 Research and development credits 5.1 4.9 2.3 Section 162(m) limitation — (0.2 ) (0.5 ) Other (2.3 ) (1.8 ) (0.2 ) Change in valuation allowance (24.0 ) (23.4 ) (23.8 ) Effective income tax rate — % — % — % Deferred tax assets and valuation allowance Deferred tax assets reflect the tax effects of net operating loss and tax credit carryforwards and temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The Company’s deferred taxes assets at December 31, 2023 2022 December 31, 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 33,322 $ 28,017 Share-based compensation 2,561 2,706 Research and development credit carryforwards 12,557 9,681 Capitalized research and development expenses 27,538 12,690 Other 1,371 934 Total deferred tax assets 77,349 54,028 Valuation allowance (77,349 ) (54,002 ) Net deferred tax assets — 26 Deferred tax liabilities: Operating lease right-of-use assets — (26 ) Total deferred tax liabilities — (26 ) Net deferred tax asset (liability) $ — $ — The valuation allowance increased by $23.3 million and $17.8 million in 2023 2022, The Company’s net operating loss carryforwards of $158.7 million are federal, of which $74.1 million expires between 2029 2037 December 31, 2023, 2024 2043. Unrecognized tax benefits As of December 31, 2023, 2022 2021, December 31, 2023, no Year ended December 31, 2023 2022 2021 Beginning balance $ 6,496 $ 5,001 $ 4,500 Expired research and development tax credits $ (50 ) $ — $ — Additions based on tax positions related to the current year 1,967 1,495 501 Ending balance $ 8,413 $ 6,496 $ 5,001 As of December 31, 2023, no 12 The Company files U.S. and Texas income tax returns. In the United States, the statute of limitations with respect to the federal income tax returns for tax years after 2019 2020 not |
Note 10 - Leases and Commitment
Note 10 - Leases and Commitments | 12 Months Ended |
Dec. 31, 2023 | |
Notes to Financial Statements | |
Leases And Commitments Disclosure [Text Block] | 10. Right-of-use Asset and Liability The Company had an operating lease for approximately 6,000 square feet of office space in Austin, Texas expiring April 30, 2024. February 22, 2023 no Cash paid for operating lease liabilities totaled $24,000, $155,000 and $109,000 during the years ended December 31, 2023, 2022 2021, Other Commitments The Company conducts its product research and development programs through a combination of internal and collaborative programs that include, among others, arrangements with universities, contract research organizations and clinical research sites. It has contractual arrangements with these organizations that are generally cancelable. The Company’s obligations under these contracts are largely based on services performed. The Company is dependent on contract development and manufacturing organizations for the manufacture of all our materials for clinical studies. |
Note 11 - 2020 Cash Incentive B
Note 11 - 2020 Cash Incentive Bonus Plan | 12 Months Ended |
Dec. 31, 2023 | |
Notes to Financial Statements | |
Cash Incentive Bonus Plan [Text Block] | Note 11. 2020 In August 2020, not not 1 2 not December 31, 2023. Plan participants will be paid all earned cash bonuses in the event of a Merger Transaction. As of December 31, 2022, March 16, 2023, not not The Company’s market capitalization for purposes of the Plan is determined based on either ( 1 one 2 The Plan triggers a potential cash bonus each time the Company’s market capitalization increases significantly, up to a maximum $5 no not no If the Company were to exceed a $5 billion market capitalization for no 1 2 may no The Plan is accounted for as a liability award. The fair value of each Valuation Milestone award will be determined once a grant date occurs and will be remeasured each reporting period. Compensation expense associated with the Plan will be recognized over the expected achievement period for each of the 14 Valuation Milestones, when a Performance Condition is considered probable of being met. In October 2020, first 2020, March 2023 During the year ended December 31, 2021, March 2023 no no no No December 31, 2023 2022. No actual cash payments were authorized or made to participants under the Plan through December 31, 2023 10 |
Note 12 - Contingencies
Note 12 - Contingencies | 12 Months Ended |
Dec. 31, 2023 | |
Notes to Financial Statements | |
Contingencies Disclosure [Text Block] | 12. The Company is, and from time to time, the Company may may no Government Investigations On November 15, 2021, No No may Securities Class Actions and Shareholder Derivative Actions Between August 27, 2021 October 26, 2021, four On June 30, 2022, four one August 18, 2022 September 14, 2020 July 26, 2022. May 11, 2023, July 3, 2023. February 22, 2024, October 12, 2023. On November 4, 2021, not November 4, 2021 June 20, 2023, two one July 5, 2022, three November 9, 2023, On February 2, 2024, October 12, 2023 August 18, 2022 October 12, 2023. The Company believes the foregoing claims are without merit and intends to defend against these lawsuits vigorously. The Company is unable to estimate the possible loss or range of loss, if any, associated with these lawsuits. On August 19, 2022, 2020 August 2020. January 6, 2023, March 10, 2023, March 14, 2023. January 25, 2024, not no |
Note 13 - Subsequent Event - Wa
Note 13 - Subsequent Event - Warrant Dividend Distribution | 12 Months Ended |
Dec. 31, 2023 | |
Notes to Financial Statements | |
Subsequent Events [Text Block] | 13. On January 3, 2024, December 22, 2023 four 16.9 Each warrant entitles the holder to purchase, at the holder’s sole expense and exclusive election, at an exercise price of $33.00 per warrant, one A Bonus Share Fraction entitles a holder to receive an additional 0.5 of a share of common stock (rounded down for any fractional share) for each warrant exercised (the “Bonus Share Fraction”) without payment of any additional exercise price. The right to receive the Bonus Share Fraction will expire upon the earlier of (i) the first first 30 January 3, 2024) 20 not not 20 not 20 Unless earlier redeemed, the warrants will expire and cease to be exercisable on November 15, 2024 ( April 15, 2024. 20 1/10 may January 3, 2024 1 2 The number of shares of Common Stock issuable upon exercise is subject to certain anti-dilution adjustments, including for share dividends, splits, subdivisions, spin-offs, consolidations, reclassifications, combinations, non-cash distributions and cash dividends. Terms of the warrants prohibit ownership by warrant exercise of 9.9% The right to exercise warrants shall be automatically suspended in a circumstance while there is no May 1, 2023. may The Company may one not x The warrants are listed and traded separately from the Company's common stock on the Nasdaq Capital Market under the ticker “SAVAW”. From January 3, 2024 February 26, 2024, 659,000 February 26, 2024. first |
Insider Trading Arrangements
Insider Trading Arrangements | 12 Months Ended |
Dec. 31, 2023 | |
Insider Trading Arr Line Items | |
Material Terms of Trading Arrangement [Text Block] | 9B. Other Information During the quarter ended December 31, 2023, none 16a 1 10b5 1 10b5 1 408. |
Rule 10b5-1 Arrangement Adopted [Flag] | false |
Non-Rule 10b5-1 Arrangement Adopted [Flag] | false |
Rule 10b5-1 Arrangement Terminated [Flag] | false |
Non-Rule 10b5-1 Arrangement Terminated [Flag] | false |
Significant Accounting Policies
Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2023 | |
Accounting Policies [Abstract] | |
Use of Estimates, Policy [Policy Text Block] | Use of Estimates The Company makes estimates and assumptions in preparing its consolidated financial statements in conformity with accounting principles generally accepted in the United States. These estimates and assumptions affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amount of revenue earned and expenses incurred during the reporting period. The Company evaluates its estimates on an ongoing basis, including those estimates related to clinical trials and manufacturing agreements. Actual results could differ from these estimates and assumptions. |
Government Assistance [Policy Text Block] | Proceeds from Grants During 2023, no 2022, 2021, |
Cash and Cash Equivalents, Policy [Policy Text Block] | Cash and Cash Equivalents and Concentration of Credit Risk The Company invests in cash and cash equivalents. The Company considers highly-liquid financial instruments with original maturities of three one |
Fair Value Measurement, Policy [Policy Text Block] | Fair Value Measurements The Company recognizes financial instruments in accordance with the authoritative guidance on fair value measurements and disclosures for financial assets and liabilities. This guidance defines fair value, establishes a framework for measuring fair value in accordance with GAAP, and expands disclosures about fair value measurements. The guidance also establishes a three ● Level 1 ● Level 2 third not 2 ● Level 3 no not 3 If a financial instrument uses inputs that fall in different levels of the hierarchy, the instrument will be categorized based upon the lowest level of input that is significant to the fair value calculation. The fair value of cash and cash equivalents was based on Level 1 December 31, 2023 2022. |
Segment Reporting, Policy [Policy Text Block] | Business Segments The Company reports segment information based on how it internally evaluates the operating performance of its business units, or segments. The Company’s operations are confined to one business segment: the development of novel drugs and diagnostics. |
Compensation Related Costs, Policy [Policy Text Block] | Stock-based Compensation The Company recognizes non-cash expense for the fair value of all stock options and other share-based awards. The Company uses the Black-Scholes option valuation model (“Black-Scholes”) to calculate the fair value of stock options, using the single-option award approach and straight-line attribution method. This model requires the input of subjective assumptions including expected stock price volatility, expected life and estimated forfeitures of each award. These assumptions consist of estimates of future market conditions, which are inherently uncertain, and therefore, are subject to management’s judgment. For all options granted, it recognizes the resulting fair value as expense on a straight-line basis over the vesting period of each respective stock option, generally three four The Company has granted share-based awards that vest upon achievement of certain performance criteria (“Performance Awards”). The Company multiplies the number of Performance Awards by the fair value of its common stock on the date of grant to calculate the fair value of each award. It estimates an implicit service period for achieving performance criteria for each award. The Company recognizes the resulting fair value as expense over the implicit service period when it concludes that achieving the performance criteria is probable. It periodically reviews and updates as appropriate its estimates of implicit service periods and conclusions on achieving the performance criteria. Performance Awards vest and common stock is issued upon achievement of the performance criteria. |
Earnings Per Share, Policy [Policy Text Block] | Net Loss per Share The Company computes basic net loss per share on the basis of the weighted-average number of common shares outstanding for the reporting period. Diluted net loss per share is computed on the basis of the weighted-average number of common shares outstanding plus potential dilutive common shares outstanding using the treasury-stock method. Potential dilutive common shares consist of outstanding common stock options and warrants. There is no Years ended December 31, 2023 2022 2021 Numerator: Net loss $ (97,217 ) $ (76,246 ) $ (32,385 ) Denominator: Shares used in computing net loss per share, basic and diluted 41,932 40,202 39,405 Net loss per share, basic and diluted $ (2.32 ) $ (1.90 ) $ (0.82 ) Dilutive common stock options excluded from net loss per share, diluted 2,123 2,055 2,211 The Company excluded common stock options and warrants outstanding, along with 57,143 restricted stock awards, from the calculation of net loss per share, diluted, because the effect of including outstanding options would have been anti-dilutive. The 57,143 restricted stock awards expired during the year ended December 31, 2022. |
Fair Value of Financial Instruments, Policy [Policy Text Block] | Fair Value of Financial Instruments Financial instruments include accounts payable, accrued expenses and other liabilities. The estimated fair value of certain financial instruments may not may |
Research and Development Expense, Policy [Policy Text Block] | Research Contracts, Prepaids and Accruals The Company has entered into various research and development contracts with research institutions and other third not |
Share-Based Payment Arrangement [Policy Text Block] | Incentive Bonus Plan In 2020, 2020 718 Stock-based Compensation 11 |
Lessee, Leases [Policy Text Block] | Leases The Company recognizes assets and liabilities that arise from leases. For operating leases, the Company is required to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments during the lease term, in the consolidated balance sheets. The Company elected the short-term lease recognition exemption for all leases that qualify. This means, for those leases that qualify, the Company does not not |
Property, Plant and Equipment, Policy [Policy Text Block] | Property and equipment Property and equipment is recorded at cost, net of accumulated depreciation. Depreciation is recorded using the straight-line method over the estimated useful lives of the assets. Owned buildings and related improvements have estimated useful lives of 39 years and approximately 10 years, respectively. Tenant improvements related to leased space are amortized using the straight-line method over the useful lives of the improvements or the remaining term of the corresponding leases, whichever is shorter. The remaining term of the corresponding leases is approximately 0.4 years. Property and equipment are reviewed for impairment when events or changes in circumstances indicate the carrying amount of an asset may not |
Intangible Assets, Finite-Lived, Policy [Policy Text Block] | Intangible assets Acquired intangible assets are recorded at fair value at the date of acquisition and primarily consist of lease-in-place agreements and leasing commissions. Intangible assets are amortized over the estimated life of the lease-in-place agreements, which approximates 0.3 years at December 31, 2023. Intangible assets are reviewed for impairment on an annual basis, and when there is reason to believe that their values have been diminished or impaired. If intangible assets are considered to be impaired, an impairment loss is recognized. |
Income Tax, Policy [Policy Text Block] | Income Taxes The Company accounts for income taxes under the asset and liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax balances are adjusted to reflect tax rates based on currently enacted tax laws, which will be in effect in the years in which the temporary differences are expected to reverse. The Company has accumulated significant deferred tax assets that reflect the tax effects of net operating loss and tax credit carryovers and temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Realization of certain deferred tax assets is dependent upon future earnings. The Company is uncertain about the timing and amount of any future earnings. Accordingly, the Company offsets these deferred tax assets with a valuation allowance. The Company accounts for uncertain tax positions in accordance with ASC 740, not |
Note 2 - Summary of Significa_2
Note 2 - Summary of Significant Accounting Policies (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Notes Tables | |
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] | Years ended December 31, 2023 2022 2021 Numerator: Net loss $ (97,217 ) $ (76,246 ) $ (32,385 ) Denominator: Shares used in computing net loss per share, basic and diluted 41,932 40,202 39,405 Net loss per share, basic and diluted $ (2.32 ) $ (1.90 ) $ (0.82 ) Dilutive common stock options excluded from net loss per share, diluted 2,123 2,055 2,211 |
Note 3 - Prepaid and Other Cu_2
Note 3 - Prepaid and Other Current Assets (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Notes Tables | |
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block] | December 31, 2023 2022 Prepaid insurance $ 759 $ 874 Contract research organization and other deposits 6,489 9,177 Interest receivable 962 — Other 287 160 Total prepaid expenses and other current assets $ 8,497 $ 10,211 |
Note 4 - Real Property and Ot_2
Note 4 - Real Property and Other Income, Expense (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Notes Tables | |
Schedule of Other Nonoperating Income (Expense) [Table Text Block] | Years ended December 31, 2023 2022 2021 Lease revenue $ 2,283 $ 2,459 $ 911 Property operating expenses (1,376 ) (1,462 ) (477 ) Other income, net $ 907 $ 997 $ 434 |
Note 5 - Property and Equipme_2
Note 5 - Property and Equipment (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Notes Tables | |
Property, Plant and Equipment [Table Text Block] | December 31, 2023 2022 Land $ 3,734 $ 3,734 Buildings 15,980 15,980 Site improvements 494 470 Tenant improvements 3,062 3,016 Furniture and equipment 868 851 Construction in progress — 13 Gross property and equipment $ 24,138 $ 24,064 Accumulated depreciation (2,284 ) (1,200 ) Property and equipment, net $ 21,854 $ 22,864 |
Note 6 - Intangible Assets (Tab
Note 6 - Intangible Assets (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Notes Tables | |
Schedule of Finite-Lived Intangible Assets [Table Text Block] | December 31, 2023 2022 Lease-in-place agreements $ 1,053 $ 1,053 Leasing commissions and other 293 290 Gross intangible assets $ 1,346 $ 1,343 Accumulated amortization (1,170 ) (721 ) Intangible assets, net $ 176 $ 622 |
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] | For the year ending December 31, 2024 172 2025 4 Total amortization $ 176 |
Note 7 - Stockholders' Equity_2
Note 7 - Stockholders' Equity and Stock-based Compensation Expense (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Notes Tables | |
Share-Based Payment Arrangement, Option, Activity [Table Text Block] | Weighted Average Weighted Average Number of Weighted Average Remaining Contractual Aggregate Intrinsic Value Options Exercise Price Term in Years in Millions Outstanding as of December 31, 2022 2,529,448 $ 12.13 3.94 $ 49.60 Options granted 1,162,000 18.91 Options exercised (602,420 ) 8.38 Options forfeited/canceled (49,999 ) 32.59 Outstanding as of December 31, 2023 3,039,029 — — $ — Vested and expected to vest at December 31, 2023 3,039,029 15.13 6.21 $ 30.28 Exercisable at December 31, 2023 1,836,174 $ 11.09 3.98 $ 26.18 |
Share-Based Payment Arrangement, Option, Exercise Price Range [Table Text Block] | Options outstanding Options exercisable Weighted average Weighted Weighted Number of remaining average Number of average Range of exercise prices outstanding contractual exercise vested exercise From To options life (in years) price options price $ 0.95 $ 3.24 804,834 4.8 $ 2.17 804,834 $ 2.17 $ 4.09 $ 13.02 656,230 2.9 $ 8.33 647,167 $ 8.34 $ 14.21 $ 16.94 62,634 1.9 $ 16.00 62,634 $ 16.00 $ 17.54 $ 17.54 800,000 9.8 $ 17.54 44,442 $ 17.54 $ 21.11 $ 77.00 715,331 7.2 $ 33.20 277,097 $ 41.29 3,039,029 6.2 $ 15.13 1,836,174 $ 11.09 |
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] | 2023 2022 2021 Volatility 152% to 155% 151% to 154% 147% to 151% Risk-free interest rates 3.82% to 4.37% 1.98% to 3.69% 1.12% to 1.42% Expected life of option (in years) 7 7 7 Dividend yield zero zero zero Forfeiture rate zero zero zero Weighted average fair value of stock options granted $ 18.21 $ 35.16 $ 65.83 |
Share-Based Payment Arrangement, Activity [Table Text Block] | Number of Performance Awards Outstanding as of December 31, 2022 7,142 Granted — Vested — Forfeited/canceled — Outstanding as of December 31, 2023 7,142 |
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] | Years ended December 31, 2023 2022 2021 Research and development $ 2,050 $ 1,631 $ 1,302 General and administrative 2,536 435 457 Total stock-based compensation expense $ 4,586 $ 2,066 $ 1,759 |
Note 9 - Income Taxes (Tables)
Note 9 - Income Taxes (Tables) | 12 Months Ended |
Dec. 31, 2023 | |
Notes Tables | |
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] | Year ended December 31, 2023 2022 2021 Tax at federal statutory rate 21 % 21 % 21 % State tax, net of federal benefit — — — Share-based compensation 0.2 (0.5 ) 1.2 Research and development credits 5.1 4.9 2.3 Section 162(m) limitation — (0.2 ) (0.5 ) Other (2.3 ) (1.8 ) (0.2 ) Change in valuation allowance (24.0 ) (23.4 ) (23.8 ) Effective income tax rate — % — % — % |
Schedule of Deferred Tax Assets and Liabilities [Table Text Block] | December 31, 2023 2022 Deferred tax assets: Net operating loss carryforwards $ 33,322 $ 28,017 Share-based compensation 2,561 2,706 Research and development credit carryforwards 12,557 9,681 Capitalized research and development expenses 27,538 12,690 Other 1,371 934 Total deferred tax assets 77,349 54,028 Valuation allowance (77,349 ) (54,002 ) Net deferred tax assets — 26 Deferred tax liabilities: Operating lease right-of-use assets — (26 ) Total deferred tax liabilities — (26 ) Net deferred tax asset (liability) $ — $ — |
Summary of Income Tax Contingencies [Table Text Block] | Year ended December 31, 2023 2022 2021 Beginning balance $ 6,496 $ 5,001 $ 4,500 Expired research and development tax credits $ (50 ) $ — $ — Additions based on tax positions related to the current year 1,967 1,495 501 Ending balance $ 8,413 $ 6,496 $ 5,001 |
Note 1 - General, Liquidity a_2
Note 1 - General, Liquidity and Basis of Presentation (Details Textual) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Retained Earnings (Accumulated Deficit) | $ (380,769) | $ (283,552) |
Note 2 - Summary of Significa_3
Note 2 - Summary of Significant Accounting Policies (Details Textual) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 USD ($) shares | Dec. 31, 2022 USD ($) shares | Dec. 31, 2021 USD ($) | |
Proceeds from Insurance Settlement, Operating Activities | $ 0 | ||
Government Assistance, Amount | $ 900 | $ 3,900 | |
Number of Operating Segments | 1 | ||
Operating Lease, Weighted Average Remaining Lease Term (Year) | 4 months 24 days | ||
Leases, Acquired-in-Place [Member] | |||
Finite-Lived Intangible Asset, Useful Life (Year) | 3 months 18 days | ||
Building [Member] | |||
Property, Plant and Equipment, Useful Life (Year) | 39 years | ||
Building Improvements [Member] | |||
Property, Plant and Equipment, Useful Life (Year) | 10 years | ||
Share-Based Payment Arrangement, Option [Member] | Minimum [Member] | |||
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) | 3 years | ||
Share-Based Payment Arrangement, Option [Member] | Maximum [Member] | |||
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) | 4 years | ||
Restricted Stock [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) | shares | 57,143 | 57,143 |
Note 2 - Summary of Significa_4
Note 2 - Summary of Significant Accounting Policies - Calculation of Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Net loss | $ (97,217) | $ (76,246) | $ (32,385) |
Shares used in computing net loss per share, basic and diluted (in shares) | 41,932 | 40,202 | 39,405 |
Net loss per share, basic and diluted (in dollars per share) | $ (2.32) | $ (1.9) | $ (0.82) |
Share-Based Payment Arrangement, Option [Member] | |||
Dilutive securities excluded from net loss per share, diluted (in shares) | 2,123 | 2,055 | 2,211 |
Note 3 - Prepaid Expenses and O
Note 3 - Prepaid Expenses and Other Current Assets - Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Prepaid insurance | $ 759 | $ 874 |
Contract research organization and other deposits | 6,489 | 9,177 |
Interest receivable | 962 | 0 |
Other | 287 | 160 |
Total prepaid expenses and other current assets | $ 8,497 | $ 10,211 |
Note 4 - Real Property and Ot_3
Note 4 - Real Property and Other Income, Expense (Details Textual) - Office Building [Member] - TEXAS | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Aug. 04, 2021 ft² |
Net Rentable Area (Square Foot) | ft² | 90,000 | ||
Percentage of Occupancy | 25% | ||
Accrual for Taxes Other than Income Taxes, Current | $ | $ 338,000 | $ 433,000 |
Note 4 - Real Property Acquisit
Note 4 - Real Property Acquisitions - Components of Other Income, Net (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Lease revenue | $ 2,283 | $ 2,459 | $ 911 |
Property operating expenses | (1,376) | (1,462) | (477) |
Other income, net | $ 907 | $ 997 | $ 434 |
Note 5 - Property and Equipme_3
Note 5 - Property and Equipment (Details Textual) - USD ($) | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Depreciation | $ 1,084,000 | $ 804,000 | $ 310,000 |
Note 5 - Property and Equipme_4
Note 5 - Property and Equipment - Components of Property and Equipment (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Gross property and equipment | $ 24,138 | $ 24,064 |
Accumulated depreciation | (2,284) | (1,200) |
Property and equipment, net | 21,854 | 22,864 |
Land [Member] | ||
Gross property and equipment | 3,734 | 3,734 |
Building [Member] | ||
Gross property and equipment | 15,980 | 15,980 |
Building Improvements [Member] | ||
Gross property and equipment | 494 | 470 |
Leasehold Improvements [Member] | ||
Gross property and equipment | 3,062 | 3,016 |
Furniture and Fixtures [Member] | ||
Gross property and equipment | 868 | 851 |
Construction in Progress [Member] | ||
Gross property and equipment | $ 0 | $ 13 |
Note 6 - Intangible Assets (Det
Note 6 - Intangible Assets (Details Textual) - USD ($) | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Amortization of Intangible Assets | $ 446,000 | $ 497,000 | $ 224,000 |
Note 6 - Intangible Assets - Co
Note 6 - Intangible Assets - Components of Intangible Assets (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Gross intangible assets | $ 1,346 | $ 1,343 |
Accumulated amortization | (1,170) | (721) |
Total amortization | 176 | 622 |
Leases, Acquired-in-Place [Member] | ||
Gross intangible assets | 1,053 | 1,053 |
Leasing Commissions and Other [Member] | ||
Gross intangible assets | $ 293 | $ 290 |
Note 6 - Intangible Assets - Am
Note 6 - Intangible Assets - Amortization Expense for Finite-lived Intangible Assets (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
2024 | $ 172 | |
2025 | 4 | |
Total amortization | $ 176 | $ 622 |
Note 7 - Stockholders' Equity_3
Note 7 - Stockholders' Equity and Stock-based Compensation Expense (Details Textual) - USD ($) | 12 Months Ended | |||||||
Nov. 22, 2022 | May 05, 2022 | Feb. 12, 2021 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | May 01, 2023 | Mar. 31, 2020 | |
Proceeds from Issuance of Common Stock | $ 0 | $ 47,329,000 | $ 189,825,000 | |||||
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ 0.001 | $ 0.001 | ||||||
Stock Options Exercised Net Settled Satisfaction Of Exercise Price (in shares) | 101,058 | |||||||
Share-Based Payment Arrangement, Option [Member] | ||||||||
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate | 0% | 0% | 0% | |||||
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | $ 24,200,000 | |||||||
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) | 2 years 9 months 18 days | |||||||
Performance Shares [Member] | ||||||||
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | $ 101,000 | |||||||
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Expirations (in shares) | 57,143 | |||||||
The 2018 Equity Incentive Plan [Member] | ||||||||
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period (Year) | 10 years | |||||||
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares) | 5,000,000 | |||||||
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ 0.001 | |||||||
The 2022 Registered Direct Offering [Member] | ||||||||
Stock Issued During Period, Shares, New Issues (in shares) | 1,666,667 | |||||||
Shares Issued, Price Per Share (in dollars per share) | $ 30 | |||||||
Proceeds from Issuance of Common Stock | $ 47,300,000 | |||||||
The 2021 Registered Direct Offering [Member] | ||||||||
Stock Issued During Period, Shares, New Issues (in shares) | 4,081,633 | |||||||
Shares Issued, Price Per Share (in dollars per share) | $ 49 | |||||||
Proceeds from Issuance of Common Stock | $ 189,800,000 | |||||||
At-the-market Common Stock Offering [Member] | ||||||||
Stock Issued During Period, Shares, New Issues (in shares) | 0 | |||||||
Equity Offering, Maximum Amount | $ 200,000,000 | $ 100,000,000 | ||||||
Equity Offering, Percentage of Commission | 3% |
Note 7 - Stockholders' Equity_4
Note 7 - Stockholders' Equity and Stock-based Compensation Expense - Stock Option Activity (Details) $ / shares in Units, $ in Thousands | 12 Months Ended |
Dec. 31, 2023 USD ($) $ / shares shares | |
Outstanding, options (in shares) | shares | 2,529,448 |
Outstanding, options, weighted average exercise price (in dollars per share) | $ / shares | $ 12.13 |
Outstanding as of December 31, 2022, weighted average contractual term (Year) | 3 years 11 months 8 days |
Outstanding as of December 31, 2022, aggregate intrinsic value | $ | $ 49,600 |
Options granted (in shares) | shares | 1,162,000 |
Options granted, weighted average exercise price (in dollars per share) | $ / shares | $ 18.91 |
Options exercised (in shares) | shares | (602,420) |
Options exercised, weighted average exercise price (in dollars per share) | $ / shares | $ 8.38 |
Options forfeited/canceled (in shares) | shares | (49,999) |
Options forfeited/canceled, weighted average exercise price (in dollars per share) | $ / shares | $ 32.59 |
Outstanding, options (in shares) | shares | 3,039,029 |
Outstanding, options, weighted average exercise price (in dollars per share) | $ / shares | $ 0 |
Vested and expected to vest at December 31, 2023 (in shares) | shares | 3,039,029 |
Vested and expected to vest at December 31, 2022, weighted average exercise price (in dollars per share) | $ / shares | $ 15.13 |
Vested and expected to vest at December 31, 2022, weighted average contractual term (Year) | 6 years 2 months 15 days |
Vested and expected to vest at December 31, 2022, aggregate intrinsic value | $ | $ 30,280 |
Exercisable at December 31, 2023 (in shares) | shares | 1,836,174 |
Exercisable at December 31, 2022, weighted average exercise price (in dollars per share) | $ / shares | $ 11.09 |
Exercisable at December 31, 2022, weighted average contractual term (Year) | 3 years 11 months 23 days |
Exercisable at December 31, 2022, aggregate intrinsic value | $ | $ 26,180 |
Note 7 - Stockholders' Equity_5
Note 7 - Stockholders' Equity and Stock-based Compensation Expense - Schedule of Stock Options by Exercise Price (Details) | 12 Months Ended |
Dec. 31, 2023 $ / shares shares | |
Options outstanding (in shares) | shares | 3,039,029 |
Options outstanding, weighted average contractual life (Year) | 6 years 2 months 12 days |
Options outstanding, weighted average exercise price (in dollars per share) | $ 15.13 |
Options exercisable (in shares) | shares | 1,836,174 |
Options exercisable, weighted average exercise price (in dollars per share) | $ 11.09 |
Range One [Member] | |
Options, exercise price, lower limit (in dollars per share) | 0.95 |
Options, exercise price, upper limit (in dollars per share) | $ 3.24 |
Options outstanding (in shares) | shares | 804,834 |
Options outstanding, weighted average contractual life (Year) | 4 years 9 months 18 days |
Options outstanding, weighted average exercise price (in dollars per share) | $ 2.17 |
Options exercisable (in shares) | shares | 804,834 |
Options exercisable, weighted average exercise price (in dollars per share) | $ 2.17 |
Range Two [Member] | |
Options, exercise price, lower limit (in dollars per share) | 4.09 |
Options, exercise price, upper limit (in dollars per share) | $ 13.02 |
Options outstanding (in shares) | shares | 656,230 |
Options outstanding, weighted average contractual life (Year) | 2 years 10 months 24 days |
Options outstanding, weighted average exercise price (in dollars per share) | $ 8.33 |
Options exercisable (in shares) | shares | 647,167 |
Options exercisable, weighted average exercise price (in dollars per share) | $ 8.34 |
Range Three [Member] | |
Options, exercise price, lower limit (in dollars per share) | 14.21 |
Options, exercise price, upper limit (in dollars per share) | $ 16.94 |
Options outstanding (in shares) | shares | 62,634 |
Options outstanding, weighted average contractual life (Year) | 1 year 10 months 24 days |
Options outstanding, weighted average exercise price (in dollars per share) | $ 16 |
Options exercisable (in shares) | shares | 62,634 |
Options exercisable, weighted average exercise price (in dollars per share) | $ 16 |
Range Four [Member] | |
Options, exercise price, lower limit (in dollars per share) | 17.54 |
Options, exercise price, upper limit (in dollars per share) | $ 17.54 |
Options outstanding (in shares) | shares | 800,000 |
Options outstanding, weighted average contractual life (Year) | 9 years 9 months 18 days |
Options outstanding, weighted average exercise price (in dollars per share) | $ 17.54 |
Options exercisable (in shares) | shares | 44,442 |
Options exercisable, weighted average exercise price (in dollars per share) | $ 17.54 |
Range Five [Member] | |
Options, exercise price, lower limit (in dollars per share) | 21.11 |
Options, exercise price, upper limit (in dollars per share) | $ 77 |
Options outstanding (in shares) | shares | 715,331 |
Options outstanding, weighted average contractual life (Year) | 7 years 2 months 12 days |
Options outstanding, weighted average exercise price (in dollars per share) | $ 33.2 |
Options exercisable (in shares) | shares | 277,097 |
Options exercisable, weighted average exercise price (in dollars per share) | $ 41.29 |
Note 7 - Stockholders' Equity_6
Note 7 - Stockholders' Equity and Stock-based Compensation Expense - Stock Option Valuation Assumptions (Details) - Share-Based Payment Arrangement, Option [Member] - $ / shares | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Expected life of option (in years) (Year) | 7 years | 7 years | 7 years |
Dividend yield | 0% | 0% | 0% |
Forfeiture rate | 0% | 0% | 0% |
Weighted average fair value of stock options granted (in dollars per share) | $ 18.21 | $ 35.16 | $ 65.83 |
Minimum [Member] | |||
Volatility | 152% | 151% | 147% |
Risk-free interest rates | 3.82% | 1.98% | 1.12% |
Maximum [Member] | |||
Volatility | 155% | 154% | 151% |
Risk-free interest rates | 4.37% | 3.69% | 1.42% |
Note 7 - Stockholders' Equity_7
Note 7 - Stockholders' Equity and Stock-based Compensation Expense - Stock Option and Performance Award Activity (Details) - Performance Shares [Member] | 12 Months Ended |
Dec. 31, 2023 shares | |
Outstanding, awards (in shares) | 7,142 |
Granted, awards (in shares) | 0 |
Vested, awards (in shares) | 0 |
Forfeited/canceled, awards (in shares) | 0 |
Outstanding, awards (in shares) | 7,142 |
Note 7 - Stockholders' Equity_8
Note 7 - Stockholders' Equity and Stock-based Compensation Expense - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Total stock-based compensation expense | $ 4,586 | $ 2,066 | $ 1,759 |
Research and Development Expense [Member] | |||
Total stock-based compensation expense | 2,050 | 1,631 | 1,302 |
General and Administrative Expense [Member] | |||
Total stock-based compensation expense | $ 2,536 | $ 435 | $ 457 |
Note 9 - Income Taxes (Details
Note 9 - Income Taxes (Details Textual) - USD ($) | 12 Months Ended | |||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | |
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent | 21% | 21% | 21% | |
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount | $ 23,300 | $ 17,800 | ||
Unrecognized Tax Benefits | 8,413,000 | $ 6,496,000 | $ 5,001,000 | $ 4,500,000 |
Unrecognized Tax Benefits that Would Impact Effective Tax Rate | 0 | |||
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued | $ 0 | |||
Open Tax Year | 2019 2020 2021 2022 | |||
Domestic Tax Authority [Member] | ||||
Operating Loss Carryforwards | $ 158,700,000 | |||
Domestic Tax Authority [Member] | Research Tax Credit Carryforward [Member] | ||||
Tax Credit Carryforward, Amount | 21,100,000 | |||
Domestic Tax Authority [Member] | Carryforward Subject to Expiration [Member] | ||||
Operating Loss Carryforwards | 74,100,000 | |||
Domestic Tax Authority [Member] | Indefinite Life Carryforwards [Member] | ||||
Operating Loss Carryforwards | $ 84,600,000 |
Note 9 - Income Taxes - Schedul
Note 9 - Income Taxes - Schedule of Effective Income Tax Reconciliation (Details) | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Tax at federal statutory rate | 21% | 21% | 21% |
State tax, net of federal benefit | 0% | 0% | 0% |
Share-based compensation | 0.20% | (0.50%) | 1.20% |
Research and development credits | 5.10% | 4.90% | 2.30% |
Section 162(m) limitation | 0% | (0.20%) | (0.50%) |
Other | (2.30%) | (1.80%) | (0.20%) |
Change in valuation allowance | (24.00%) | (23.40%) | (23.80%) |
Effective income tax rate | 0% | 0% | 0% |
Note 9 - Income Taxes - Sched_2
Note 9 - Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 |
Net operating loss carryforwards | $ 33,322 | $ 28,017 |
Share-based compensation | 2,561 | 2,706 |
Research and development credit carryforwards | 12,557 | 9,681 |
Capitalized research and development expenses | 27,538 | 12,690 |
Other | 1,371 | 934 |
Total deferred tax assets | 77,349 | 54,028 |
Valuation allowance | (77,349) | (54,002) |
Net deferred tax assets | 0 | 26 |
Operating lease right-of-use assets | 0 | (26) |
Total deferred tax liabilities | 0 | (26) |
Net deferred tax asset (liability) | $ 0 | $ 0 |
Note 9 - Income Taxes - Sched_3
Note 9 - Income Taxes - Schedule of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
Beginning balance | $ 6,496 | $ 5,001 | $ 4,500 |
Expired research and development tax credits | (50) | 0 | 0 |
Additions based on tax positions related to the current year | 1,967 | 1,495 | 501 |
Ending balance | $ 8,413 | $ 6,496 | $ 5,001 |
Note 10 - Leases and Commitme_2
Note 10 - Leases and Commitments (Details Textual) | 12 Months Ended | ||
Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) ft² | Dec. 31, 2021 USD ($) | |
Operating Lease, Payments | $ | $ 24,000 | $ 155,000 | $ 109,000 |
Lease for Office Space in Austin, Texas [Member] | |||
Area of Real Estate Property (Square Foot) | ft² | 6,000 |
Note 11 - 2020 Cash Incentive_2
Note 11 - 2020 Cash Incentive Bonus Plan (Details Textual) - Cash Incentive Bonus Plan [Member] $ in Thousands | 12 Months Ended | ||
Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Oct. 31, 2020 USD ($) | |
Cash Bonus Incentive, Incremental Amounts | 14 | 11 | |
Performance Plan, Minimum Number of Days Valuation Milestone Must be Achieved and Maintained (Day) | 20 days | ||
Percentage Valuation Milestone Cash Bonus Award Subject to Approval and Adjustment | 67% | ||
Cash Incentive Bonus Award | $ 6,500 | ||
Share-Based Payment Arrangement, Expense, after Tax | $ 0 | ||
Payments for Cash Incentive Bonus | 0 | ||
Minimum [Member] | |||
Performance Plan, Valuation Milestone Amount | $ 200,000 | 74,900 | |
Cash Incentive Bonus Award, Exceeds Maximum | 111,400 | ||
Maximum [Member] | |||
Performance Plan, Valuation Milestone Amount | 5,000,000 | $ 202,300 | |
Cash Incentive Bonus Award, Exceeds Maximum | $ 289,700 |
Note 12 - Contingencies (Detail
Note 12 - Contingencies (Details Textual) | 2 Months Ended | 20 Months Ended | |||
Jul. 05, 2022 | Jun. 30, 2022 | Oct. 26, 2021 | Jun. 20, 2023 | Jun. 20, 2023 | |
Violations of Federal Securities Laws [Member] | |||||
Loss Contingency, New Claims Filed, Number | 1 | 4 | |||
Shareholder Derivative Actions, Texas Court [Member] | |||||
Loss Contingency, New Claims Filed, Number | 4 | 2 | |||
Shareholder Derivative Actions, Texas State Court Member | |||||
Loss Contingency, New Claims Filed, Number | 1 | ||||
Shareholder Derivative Actions, Delaware Court [Member] | |||||
Loss Contingency, New Claims Filed, Number | 1 | ||||
Shareholder Derivative Actions [Member] | |||||
Loss Contingency, New Claims Filed, Number | 3 |
Note 13 - Subsequent Event - _2
Note 13 - Subsequent Event - Warrant Dividend Distribution (Details Textual) - USD ($) $ / shares in Units, $ in Thousands | 2 Months Ended | 12 Months Ended | |||||
Jan. 03, 2024 | Dec. 22, 2023 | Feb. 26, 2024 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Nov. 15, 2024 | |
Volume Weighted Average Price (in dollars per share) | $ 26.4 | ||||||
Proceeds from Warrant Exercises | $ 0 | $ 0 | $ 692 | ||||
Subsequent Event [Member] | |||||||
Redemption Percentage of Warrants | 0.10% | ||||||
Warrant Redemption Price (in dollars per share) | $ 0.01 | ||||||
Class of Warrant or Right, Exercised During Period (in shares) | 659,000 | ||||||
Proceeds from Warrant Exercises | $ 21,800 | ||||||
Stock Issued During Period, Shares, Warrant Exercises (in shares) | 989,000 | ||||||
Proceeds From Warrants Exercised That Obligated to Pay Commission | $ 20,000 | ||||||
Commission Percentage of Gross Proceeds | 2.50% | ||||||
Warrants to Purchase Common Stock [Member] | |||||||
Class Of Warrant Or Right Issued During Period (in shares) | 4 | ||||||
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | 10 | ||||||
Warrants to Purchase Common Stock [Member] | Subsequent Event [Member] | |||||||
Class Of Warrant Or Right Issued During Period (in shares) | 16,900,000 | ||||||
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ 33 | ||||||
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares) | 1 | ||||||
Bonus Share Fraction [Member] | Subsequent Event [Member] | |||||||
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares) | 0.5 |