Viracta Therapeutics (VIRX) 10-K 16 Mar 22 2021 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Mar. 04, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Registrant Name	VIRACTA THERAPEUTICS, INC.
Entity Central Index Key	0001061027
Entity Current Reporting Status	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		37,485,823
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	false
Entity File Number	000-51531
Entity Tax Identification Number	94-3295878
Entity Address, Address Line One	2533 S. Coast Hwy. 101, Suite 210
Entity Address, City or Town	Cardiff
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92007
Entity Public Float			$ 312.6
City Area Code	858
Local Phone Number	400-8470
Document Annual Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	DE
Trading Symbol	VIRX
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Security Exchange Name	NASDAQ
Auditor Name	Ernst & Young LLP
Auditor Location	San Diego, California
Auditor Firm ID	42
Documents Incorporated by Reference	Certain information required by Part III of this Annual Report on Form 10-K is incorporated by reference from the registrant's definitive proxy statement for the registrant's 2022 annual meeting of stockholders, which will be filed with the Securities and Exchange Commission within 120 days after the close of the registrant's fiscal year ended December 31, 2021

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 103,554,000	$ 47,089,000
Prepaid expenses and other current assets	1,719,000	110,000
Total current assets	105,273,000	47,199,000
Property and equipment, net	242,000	44,000
Operating lease right-of-use asset	640,000	986,000
Other assets	2,397,000	76,000
Total assets	108,552,000	48,305,000
Current Liabilities:
Accounts payable	2,901,000	1,557,000
Accrued expenses	5,802,000	3,362,000
Operating lease liabilities	381,000	334,000
Current portion of long-term debt	0	1,031,000
Total current liabilities	9,084,000	6,284,000
Long-term debt, net	4,819,000	4,155,000
Operating lease liabilities, less current portion	278,000	658,000
Preferred stock warrant liability	0	106,000
Commitments and contingencies
Stockholders' equity (deficit):
Convertible preferred stock, $0.0001 par value; 10,000,000 shares authorized as of December 31, 2021; 10,248 shares issued and outstanding as of December 31, 2021	5,452,000	0
Common stock, $0.0001 par value; 400,000,000 shares authorized; 37,281,226 and 905,987 shares issued and outstanding at December 31, 2021 and December 31, 2020, respectively	4,000	1,000
Additional paid-in capital	254,592,000	4,714,000
Accumulated deficit	(165,677,000)	(50,915,000)
Total stockholders' equity (deficit)	94,371,000	(46,200,000)
Total liabilities and stockholders' equity (deficit)	108,552,000	48,305,000
Series A-1 Convertible Preferred Stock [Member]
Current Liabilities:
Convertible Preferred Stock	0	2,968,000
Stockholders' equity (deficit):
Total stockholders' equity (deficit)		2,968,000
Series B Convertible Preferred Stock [Member]
Current Liabilities:
Convertible Preferred Stock	0	15,484,000
Stockholders' equity (deficit):
Total stockholders' equity (deficit)		15,484,000
Series C Convertible Preferred Stock [Member]
Current Liabilities:
Convertible Preferred Stock	0	9,392,000
Stockholders' equity (deficit):
Total stockholders' equity (deficit)		9,392,000
Series D Convertible Preferred Stock [Member]
Current Liabilities:
Convertible Preferred Stock	0	16,589,000
Stockholders' equity (deficit):
Total stockholders' equity (deficit)		16,589,000
Series E Convertible Preferred Stock [Member]
Current Liabilities:
Convertible Preferred Stock	$ 0	38,869,000
Stockholders' equity (deficit):
Total stockholders' equity (deficit)		$ 38,869,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Preferred stock, par value	$ 0.0001
Preferred stock, shares authorized	10,000,000
Preferred stock, shares issued	10,248
Preferred stock, shares outstanding	10,248
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares issued	37,424,863	905,987
Common stock, shares outstanding	37,424,863	905,987
Series A-1 Convertible Preferred Stock [Member]
Convertible Preferred Shares, Par Value Per Share		$ 0.0001
Convertible Preferred Shares, Authorized		4,819,012
Convertible Preferred Shares, Issued		4,819,012
Convertible Preferred Shares, Outstanding		4,819,012
Convertible Preferred Shares, Redemption Value		$ 13,720,612
Series B Convertible Preferred Stock [Member]
Convertible Preferred Shares, Par Value Per Share		$ 0.0001
Convertible Preferred Shares, Authorized		2,788,249
Convertible Preferred Shares, Issued		2,788,249
Convertible Preferred Shares, Outstanding		2,788,249
Convertible Preferred Shares, Redemption Value		$ 16,811,782
Series C Convertible Preferred Stock [Member]
Convertible Preferred Shares, Par Value Per Share		$ 0.0001
Convertible Preferred Shares, Authorized		1,587,722
Convertible Preferred Shares, Issued		1,587,722
Convertible Preferred Shares, Outstanding		1,587,722
Convertible Preferred Shares, Redemption Value		$ 10,695,494
Series D Convertible Preferred Stock [Member]
Convertible Preferred Shares, Par Value Per Share		$ 0.0001
Convertible Preferred Shares, Authorized		2,240,916
Convertible Preferred Shares, Issued		2,224,329
Convertible Preferred Shares, Outstanding		2,224,329
Convertible Preferred Shares, Redemption Value		$ 16,774,988
Series E Convertible Preferred Stock [Member]
Convertible Preferred Shares, Par Value Per Share		$ 0.0001
Convertible Preferred Shares, Authorized		7,472,730
Convertible Preferred Shares, Issued		7,392,240
Convertible Preferred Shares, Outstanding		7,392,240
Convertible Preferred Shares, Redemption Value		$ 39,999,997

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating expenses:
Research and development	$ 23,861	$ 13,467
Purchased and acquired in-process research and development	88,478	0
General and administrative	15,437	5,348
Total operating expenses	127,776	18,815
Gain on Royalty Purchase Agreement	13,500	0
Loss from operations	(114,276)	(18,815)
Other income (expense)
Gain on forgiveness of PPP Loan	257	0
Interest income	38	48
Interest expense	(491)	(216)
Other expense	(290)	(34)
Total other expense	(486)	(202)
Net loss and comprehensive loss	$ (114,762)	$ (19,017)
Net loss per share of common stock, basic and diluted	$ (3.60)	$ (58.56)
Weighted-average shares used to compute basic and diluted net loss per share	31,870,067	324,728

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Preferred Stock [Member]	Series A-1 Convertible Preferred Stock [Member]	Series B Convertible Preferred Stock [Member]	Series C Convertible Preferred Stock [Member]	Series D Convertible Preferred Stock [Member]	Series E Convertible Preferred Stock [Member]
Beginning Balance at Dec. 31, 2019	$ (28,383)		$ 3,515	$ (31,898)		$ 2,968	$ 15,484	$ 9,392	$ 16,589
Beginning Balance, shares at Dec. 31, 2019		72,000				4,819,000	2,788,000	1,588,000	2,224,000
Exercise of warrants and stock options to purchase common stock	848	$ 1	847
Exercise of warrants and stock options to purchase common stock, shares		830,000
Vesting of early exercise of stock options, shares		4,000
Vesting of early exercise of stock options,Value	4		4
Issuance of convertible preferred stock net issuance cost, shares										7,392,000
Issuance of convertible preferred stock net issuance cost										$ 38,869
Share-based compensation	348		348
Net loss	(19,017)			(19,017)
Ending Balance at Dec. 31, 2020	(46,200)	$ 1	4,714	(50,915)		$ 2,968	$ 15,484	$ 9,392	$ 16,589	$ 38,869
Ending Balance, shares at Dec. 31, 2020		906,000				4,819,000	2,788,000	1,588,000	2,224,000	7,392,000
Exercise of warrants and stock options to purchase common stock	$ 339		339
Exercise of warrants and stock options to purchase common stock, shares	301,000	411,000
Vesting of restricted stock units, shares		107,000
Vesting of early exercise of stock options, shares		4,000
Vesting of early exercise of stock options,Value	$ 3		3
Issuance of common stock net of issuance costs	62,317	$ 1	62,316
Issuance of common stock net of issuance costs, shares		12,012,000
Issuance of common stock to fomer stockholders of Sunesis upon Merger	97,982		97,982
Issuance of common stock to fomer stockholders of Sunesis upon Merger, shares		5,173,000
Conversion of convertible preferred stock into common stock upon Merger	83,302	$ 2	83,300			$ (2,968)	$ (15,484)	$ (9,392)	$ (16,589)	$ (38,869)
Conversion of convertible preferred stock into common stock upon Merger, shares		18,812,000				(4,819,000)	(2,788,000)	(1,588,000)	(2,224,000)	(7,392,000)
Reclassification of preferred stock warrant liability to equity	396		396
Issuance of convertible preferred stock to former stockholders of Sunesis upon Merger	5,452				$ 5,452
Issuance of convertible preferred stock to former stockholders of Sunesis upon Merger, shares					10,000
Share-based compensation	5,542		5,542
Net loss	(114,762)			(114,762)
Ending Balance at Dec. 31, 2021	$ 94,371	$ 4	$ 254,592	$ (165,677)	$ 5,452
Ending Balance, shares at Dec. 31, 2021	0	37,425,000			10,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net loss	$ (114,762)	$ (19,017)
Adjustments to reconcile net loss to net cash used in operating activities:
Gain on forgiveness of PPP Loan	(257)	0
Acquired in-process research and development	84,478	0
Purchased in-process research and development	4,000	0
Share-based compensation expense	5,542	348
Depreciation and amortization	178	32
Change in fair value of preferred stock warrant liability	290	12
Change in operating assets and liabilities:
Prepaid expenses and other current assets	(1,045)	(28)
Other assets	884	(49)
Accounts payable	922	969
Accrued liabilities	907	1,674
Lease liabilities, net	12	5
Net cash used in operating activities	(18,851)	(16,054)
Investing activities
Purchase of property and equipment	(252)	(55)
Purchase of in-process research and development	(4,000)	0
Cash acquired in connection with the Merger	17,143	0
Net cash provided by (used in) investing activities	12,891	(55)
Financing activities
Proceeds from debt, net of issuance costs	(234)	5,260
Issuance of common stock, net of issuance costs	62,320	851
Issuance of preferred stock for cash, net of offering costs	0	38,869
Exercise of warrants and stock options to purchase common stock	339	0
Net cash provided by financing activities	62,425	44,980
Net increase in cash and cash equivalents	56,465	28,871
Cash and cash equivalents at beginning of period	47,089	18,218
Cash and cash equivalents at end of period	103,554	47,089
Supplemental disclosure of cash flow information
Interest paid	343	115
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	0	1,106
Noncash financing activities
Warrants issued in connection with debt	0	94
Warrant liability reclassification to equity	396	0
Issuance of convertible preferred stock upon merger	5,452	0
Conversion of convertible preferred stock into common stock upon Merger	83,302	0
Issuance of common stock upon Merger	$ 97,982	$ 0

Organization and Basis of Prese

Organization and Basis of Presentation	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	1. Organization and Basis of Presentation Viracta Therapeutics, Inc. (“Viracta,” the “Company,” or the “combined company”), formerly known as Sunesis Pharmaceuticals, Inc., was incorporated in the state of Delaware in February 1998 and is based in San Diego, California. Viracta is a precision oncology company, focused on the development of new medicines targeting virus-associated malignancies. The Company is currently conducting three clinical trials for its combination product candidate as a potential therapy for the treatment of relapsed/refractory Epstein-Barr virus-positive lymphoma. Merger Transaction between Private Viracta Therapeutics, Inc. and Sunesis Pharmaceuticals, Inc. and Name Change On November 29, 2020, the Company, then operating as Sunesis Pharmaceuticals, Inc., entered into an agreement and plan of merger and reorganization (the “Merger Agreement”) with privately-held Viracta Therapeutics, Inc. (“Private Viracta”) and Sol Merger Sub, Inc., a wholly-owned subsidiary of the Company (“Merger Sub”). On February 24, 2021, transactions contemplated by the Merger Agreement were completed, and Merger Sub merged into Private Viracta, with Private Viracta as surviving the merger as a wholly owned subsidiary of the Company (the “Merger”). Sunesis changed its name to Viracta Therapeutics, Inc. On February 25, 2021, the combined company’s common stock began trading on The Nasdaq Global Select Market under the ticker symbol “VIRX”. Except as otherwise indicated, references herein to “Viracta,” the “Company,” or the “combined company”, refer to Viracta Therapeutics, Inc. on a post-Merger basis, and the term “Private Viracta” refers to the business of privately-held Viracta Therapeutics, Inc., prior to the completion of the Merger. References to “Sunesis” refer to Sunesis Pharmaceuticals, Inc. prior to completion of the Merger. Pursuant to the terms of the Merger Agreement, each outstanding share of Private Viracta common stock outstanding immediately prior to the closing of the Merger was converted into approximately 0.1119 shares of Company common stock (the “Exchange Ratio”), after taking into account the Reverse Stock Split, as defined below. Immediately prior to the closing of the Merger, all shares of Private Viracta preferred stock then outstanding were exchanged into shares of common stock of Private Viracta. In addition, all outstanding options exercisable for common stock of Private Viracta and warrants exercisable for capital stock of Private Viracta became options and warrants exercisable for the same number of shares of common stock of the Company multiplied by the Exchange Ratio at an exercise price equal to the pre-Merger price divided by the Exchange Ratio. Immediately following the Merger, stockholders of Private Viracta owned approximately 86 % of the outstanding common stock of the combined company. This transaction was accounted for as a reverse asset acquisition in accordance with generally accepted accounting principles in the United States of America (“GAAP”), as Viracta was considered to be acquiring Sunesis and the Merger was accounted for as an asset acquisition, even though Sunesis was the legal acquirer and the issuer of the common stock in the Merger. This determination was primarily based on the facts that, immediately following the Merger: (i) Private Viracta’s stockholders owned a substantial majority of the voting rights in the combined company, (ii) Private Viracta designated a majority of the members of the initial board of directors of the combined company, and (iii) Private Viracta’s senior management holds all key positions in the senior management of the combined company. As a result, as of the closing date of the Merger, the net assets of Sunesis were recorded at their acquisition-date relative fair values in the accompanying consolidated financial statements of the Company and the reported operating results prior to the Merger are those of Private Viracta. To determine the accounting for this transaction under GAAP, a company must assess whether an integrated set of assets and activities should be accounted for as an acquisition of a business or an asset acquisition. The guidance required an initial screen test to determine if substantially all of the fair value of the gross assets acquired was concentrated in a single asset or group of similar assets. The initial screen test was not met as there was no single asset or group of similar assets for Sunesis that represented a significant majority in this acquisition. However, at the time of the closing of the Merger, Sunesis did not have processes or an organized workforce that significantly contributed to its ability to create outputs, and substantially all of its fair value was concentrated in cash, working capital, and in-process research and development (“IPR&D”). As such, the acquisition was treated as an asset acquisition. Concurrent with the execution of the Merger Agreement, Private Viracta entered into an agreement for the sale of common stock in a private placement, which was completed immediately prior to the close of the Merger and resulted in gross proceeds of approximately $ 65.0 million. In connection with the closing of the Merger and the concurrent private placement of common stock, the holders of the Company’s preferred stock waived their right to exchange their shares into any class of the Company’s stock other than common stock. On February 24, 2021, in connection with, and prior to the completion of, the Merger, the Company effected a 3.5-for-one reverse stock split of its then outstanding common stock (the “Reverse Stock Split”). The par value and the authorized shares of the common stock were not adjusted as a result of the Reverse Stock Split. Unless otherwise noted herein, references to share and per-share amounts give retroactive effect to the Reverse Stock Split and the Exchange Ratio which was effectuated upon the Merger. Liquidity and Risks As of December 31, 2021, the Company has devoted substantially all of its efforts to product development and has not realized product sales revenues from its planned principal operations. The Company has a limited operating history, and the sales and income potential of the Company’s business and market are unproven. The Company has experienced net losses since its inception and, as of December 31, 2021, had an accumulated deficit of $ 165.7 million. The Company expects to continue to incur net losses for at least the next several years. A successful transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support the Company’s cost structure. If the Company is unable to generate revenues adequate to support its cost structure, the Company will need to raise additional equity through the issuance of its common stock, through other equity or debt financings or through collaborations or partnerships with other companies. As of December 31, 2021, the Company had cash and cash equivalents of approximately $ 103.6 million and working capital of $ 96.2 million. In February 2021, as disclosed above, Private Viracta completed the sale of common stock in a private placement resulting in gross proceeds of approximately $ 65.0 million. Additionally, the Company received approximately $ 17.1 million in cash and cash equivalents in the Merger previously discussed. Finally, in March 2021, the Company received $ 13.5 million in upfront proceeds related to the Royalty Purchase Agreement with XOMA (US) LLC (see Note 5). On November 4, 2021, the Company entered into a loan and security agreement with Silicon Valley Bank (“SVB”) and Oxford Finance LLC (“Oxford”) for up to $ 50.0 million, with $ 5.0 million refinanced at the time of entering into the agreement and $ 45.0 million available under certain circumstances. Based on the Company’s current financial position and business plan, management believes that its existing cash and cash equivalents, as well as its credit facility, will be sufficient to fund the Company’s planned operations for at least twelve months from the issuance date of these consolidated financial statements. The COVID-19 pandemic has caused significant business disruption around the globe. The extent of the impact of COVID-19 on the Company’s operational and financial performance will depend on certain developments, including the duration and spread of the pandemic and the impact on the Company’s clinical trials, employees, and vendors. At this point, the degree to which COVID-19 may impact the Company’s financial condition or results of operations is uncertain. A continued and prolonged pandemic could have a material and adverse impact on financial results and business operations of the Company, including the timing and ability of the Company to complete certain clinical trials and other efforts required to advance the development of its product candidates and raise additional capital.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries and have been prepared in accordance with GAAP. All intercompany balances and transactions have been eliminated upon consolidation. Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that 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 amounts of expenses during the reporting period. Actual results could differ materially from those estimates. Concentrations of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash and cash equivalents. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity from the date of purchase of three months or less to be cash equivalents. Property and Equipment Property and equipment, which consisted of office equipment, were stated at cost and depreciated over the estimated useful lives of the assets (three to five years) using the straight-line method. Leasehold improvements were amortized over the shorter of their estimated useful lives or the lease term. Leases The Company classifies leases as either operating or finance leases at inception and as necessary at modification. Leased assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. The Company does not obtain and control its right to use the identified asset until the lease commencement date. Operating leases are included in operating lease right-of-use (“ROU”) assets, and operating lease liabilities on the Company’s balance sheets. Operating lease ROU assets and liabilities are recognized at lease commencement date based on the present value of lease payments over the lease term. When readily determinable, the Company uses the rate implicit in the lease to discount lease payments; however, when the rate is not readily determinable, the Company uses the incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The incremental borrowing rate is the rate of interest that the Company would have to pay to borrow an amount equal to the lease payments on a collateralized basis over a similar term and in a similar economic environment. The operating lease ROU asset also includes any initial direct costs, lease payments made prior to lease commencement, and lease incentives received. Variable lease payments are expensed as incurred and are not included within the ROU asset and lease liability calculation. The Company’s lease terms are the noncancelable period and may include options to extend the lease when it is reasonably certain that it will exercise that option. Lease cost for lease payments is recognized on a straight-line basis over the lease term. The Company does not separate lease and non-lease components. The Company does not recognize ROU assets and lease liabilities for short-term leases, which have a lease term of twelve months or less and do not include an option to purchase the underlying asset that the Company is reasonably certain to exercise. Lease cost for short-term leases is recognized on a straight-line basis over the lease term. Revenue Recognition Revenue is recognized when control of the promised goods or services is transferred to the Company’s customers in an amount that reflects the consideration the Company expects to receive from its customers in exchange for those goods and services. This process involves identifying the contract with a customer, determining the performance obligations in the contract, determining the transaction price, allocating the contract price to the distinct performance obligations in the contract, and recognizing revenue when or as the Company satisfies the performance obligation(s). At contract inception, the Company assesses the goods and services promised within each contract and assesses whether each promised good or service is distinct and determines that those are performance obligations. A performance obligation is considered distinct from other obligations in a contract when it provides a benefit to the customer either on its own or together with other resources that are readily available to the customer and is separately identified in the contract. The Company considers factors such as the research, manufacturing and commercialization capabilities of the collaboration partner and the availability of the associated expertise in the general marketplace. The Company considers a performance obligation satisfied once the Company has transferred control of a good or service to the customer, meaning the customer has the ability to use and obtain the benefit of the good or service. The Company recognizes revenue for satisfied performance obligations only when the Company determines there are no uncertainties regarding payment terms or transfer of control. Collaborative Arrangements The Company evaluates collaboration arrangements to determine whether units of account within the collaboration arrangement exhibit the characteristics of a vendor and customer relationship. For arrangements and units of account where a customer relationship exists, the Company applies the revenue recognition guidance. The Company enters into collaborative arrangements with partners that may include payment to the Company of one or more of the following: (i) license fees; (ii) payments related to the achievement of developmental, regulatory, or commercial milestones; and (iii) royalties on net sales of licensed products. If a contract has multiple performance obligations, the Company allocates the transaction price to each distinct performance obligation in an amount that reflects the consideration the Company is entitled to receive in exchange for satisfying each distinct performance obligation. For each distinct performance obligation, revenue is recognized when (or as) the Company transfers control of the product or the service applicable to such performance obligation. The Company evaluates each performance obligation to determine if it can be satisfied at a point in time or over time. In addition, variable consideration must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price. License Fees If a license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from upfront fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. Milestone Payments At the inception of each arrangement that includes milestone payments (variable consideration), the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price. If it is probable that a milestone event would occur at the inception of the arrangement, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each reporting period, the Company evaluates the probability of achievement of such milestones and any related constraint(s), and if necessary, may adjust the Company’s estimate of the overall transaction price. To date, the Company has not recognized any milestone revenue resulting from its collaborative arrangements. Royalties For arrangements that include sales-based royalties, including milestone payments based on the level of sales, the Company recognizes revenue when the related sales occur. To date, the Company has not recognized any royalty revenue resulting from its collaborative arrangements. Clinical Trial and Contracts Accruals The Company accrues clinical trial costs based on work performed. In determining the amount to accrue, the Company relies on estimates of total costs incurred based on enrollment, the completion of clinical trials and other events. The Company follows this method because it is believed to be reasonably dependable estimates of the costs applicable to various stages of a clinical trial can be made. However, the actual costs and timing of clinical trials are highly uncertain, subject to risks and may change depending on a number of factors. Differences between the actual clinical trial costs and the estimated clinical trial costs that have been accrued in any prior period are recognized in the subsequent period in which the actual costs become known. Historically, estimated accrued expenses have approximated actual expenses incurred; however, material differences could occur in the future. Research and Development Expenses Research and development costs are expensed as incurred. These costs consist primarily of salaries and other personnel-related expenses, including share-based compensation; facility-related expenses; and services performed by clinical research organizations, research institutions, and other outside service providers. The Company makes estimates of its accrued expenses as of each balance sheet date in the consolidated financial statements based on facts and circumstances known to us at that time. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly. This process involves reviewing contract and purchase orders, reviewing the terms of vendor agreements, communicating with applicable personnel to identify services that have been performed on the Company's behalf and estimating the level of service performed and the associated cost incurred for the services when it has not yet been invoiced or otherwise notified of actual cost. The majority of the Company's service providers invoice monthly in arrears for services performed. Income Taxes Income taxes are accounted for under the asset and liability method. This approach requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of the differences between the tax basis of assets or liabilities and their carrying amounts in the consolidated financial statements using the enacted tax rates and laws that are anticipated to be in effect when the differences are expected to reverse. The Company provides a valuation allowance against net deferred tax assets if it is more likely than not that these items will either expire before the Company is able to realize their benefit or if future deductibility is uncertain. In accordance with the accounting standards for uncertain tax positions, the Company evaluates the recognition threshold and measurement attribute criteria for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by taxing authorities. Share-Based Compensation The Company accounts for share-based compensation expense related to stock options granted to employees, members of the board of directors, and outside consultants by estimating the fair value of each stock option on the date of grant using the Black-Scholes option pricing model. The Company accounts for restricted stock units (“RSUs”) by determining the fair value of each restricted stock unit based on the closing market price of the common stock on the date of grant. The Company recognizes share-based compensation on a straight-line basis over the requisite service period of the stock-based award, and forfeitures are recognized as they occur. The estimate of fair value for share-based compensation for stock options requires management to make estimates and judgments about, among other things, employee exercise behavior and volatility of the Company’s common stock. The judgments directly affect the amount of compensation expense that will be recognized. Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is used in making decisions regarding resource allocation and assessing performance. To date, the Company has viewed its operations and managed its business as one segment operating in the United States. All long-lived assets were located in the United States at December 31, 2021 and December 31, 2020. Fair Value Measurements The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or non-recurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market- based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets. Level 2: Inputs, other than the quoted prices in active markets that are observable either directly or indirectly. Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. The carrying amounts of the Company’s cash and cash equivalents, prepaid expenses, accounts payable and accrued liabilities approximate fair values for these financial instruments due to their short maturities. The money market funds, classified as cash equivalents, are Level 1 and had an amortized cost and estimated fair value of $ 14.9 million as of December 31, 2021. The Company had no money market funds prior to 2021. The preferred st ock warrant liability, a level 3 fair value measurement, was $ 0 a s of December 31, 2021 , due to the reclassification to equity, and $ 106,000 as of December 31, 2020. The Company had no liabilities measured at fair value on a recurring basis as of December 31, 2021 . The Company had no assets or liabilities measured at fair value on a recurring basis as of December 31, 2020, other than the preferred stock warrant liability. Preferred Stock Warrant Liability The assumptions used in the Black-Scholes option pricing model to determine the fair value of the preferred stock warrant liability were as follows: February 24, 2021 Expected volatility 90.2 % Risk-free interest rate 1.38 % Expected dividend yield 0 % Expected term 9.3 years Fair value per share of preferred stock $ 17.15 The following table provides a reconciliation of the preferred stock warrant liability measured at fair value using Level 3 significant unobservable inputs (in thousands): Preferred Stock Balance at December 31, 2020 $ 106 Change in fair value of preferred stock warrant liability 290 Reclassification to equity ( 396 ) Balance at December 31, 2021 $ — Net Loss Per Share Basic loss per common share is computed by dividing net loss by the weighted average number of common shares and warrants to purchase common stock for nominal consideration outstanding during the period. Diluted loss per common share is computed by dividing net loss by the weighted average number of common shares outstanding, plus the impact of common shares, if dilutive, resulting from the exercise of outstanding common stock equivalents. For all periods presented, there is no difference in the number of shares used to compute basic and diluted shares outstanding due to the Company's net loss position. The following securities are excluded from the calculation of weighted average dilutive common shares because their inclusion would have been anti-dilutive: December 31, 2021 2020 Shares issuable upon conversion of preferred stock 292,799 18,811,552 Common stock options and RSUs outstanding 4,797,240 1,127,842 Warrants to purchase preferred stock — 23,100 Warrants to purchase common stock 23,100 — Total excluded securities 5,113,139 19,962,494 Recently Adopted Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt – Debt with Conversion and Other options (Subtopic 470-20) and Derivative and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40) . The amendments in this ASU reduce the number of accounting models for convertible debt instruments and convertible preferred stock, as well as amend the guidance for the derivatives scope exception for contracts in an entity’s own equity to reduce form-over-substance-based accounting conclusions. In addition, this ASU improves and amends the related earnings per share guidance. The amendments in this ASU are effective for the Company on January 1, 2024, including interim periods within those fiscal years. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. Adoption is either a modified retrospective method or a fully retrospective method of transition. The Company early adopted ASU 2020-06 on January 1, 2021, electing the modified retrospective transition method that allows for a cumulative-effect adjustment in the period of adoption. The adoption of ASU 2020-06 did not have a material impact on the Company’s consolidated financial statements. In October 2021, the FASB issued ASU No. 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers. The amendment requires acquiring entities to apply Topic 606 to recognize and measure contract assets and contract liabilities in a business combination. The ASU will be effective for the Company for the annual periods beginning after December 15, 2022, with early adoption permitted. The Company early adopted ASU 2021-08 in the fourth quarter of 2021 with no material impact on its consolidated financial statements. Recently Issued Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board or other standard setting bodies that the Company will adopt as of the specified effective date. The Company has evaluated recently issued accounting pronouncements and as a result, based on the Company's preliminary assessment, do not believe any will have a material impact on the consolidated financial statements or related footnote disclosures.

Collaboration and License Agree

Collaboration and License Agreements	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaboration and License Agreements	3. Collaboration and License Agreements Shenzhen Salubris Pharmaceuticals Co. Ltd. License Agreement On November 30, 2018, the Company entered into a License Agreement (the “Salubris Agreement”) with Shenzhen Salubris Pharmaceutical Co. Ltd., (“Salubris”), pursuant to which the Company granted an exclusive, royalty-bearing license, with the right to grant sublicenses to Salubris to research, develop, use, make, have made, sell, offer for sale, have sold, import, and otherwise commercialize nanatinostat in combination with an antiviral drug such as valganciclovir in the Republic of China, excluding Hong Kong, Macau, and Taiwan. On August 19, 2021, the Company, through its wholly-owned subsidiary, Viracta Subsidiary, Inc., entered into a Mutual Termination Agreement with Salubris, effective August 20, 2021 (the “Termination Agreement”), pursuant to which the parties agreed to terminate the Salubris Agreement. Under the terms of the Termination Agreement, the Company paid Salubris a payment in the amount of $ 4.0 million on the effective date of the Termination Agreement, and all licenses granted by the Company to Salubris automatically terminated. The Company recorded the $ 4.0 million payment as purchased and acquired in-process research and development in the statement of operations and comprehensive loss for the year ended December 31, 2021. ImmunityBio License Agreement On May 1, 2017, the Company entered into a License Agreement (the “NK Agreement”) with ImmunityBio, Inc., formerly NantKwest, Inc. (“ImmunityBio”) whereby the Company granted an exclusive worldwide license to ImmunityBio and its affiliates to develop and commercialize nanatinostat for use in combination with NK cell immunotherapies. ImmunityBio will be responsible for conducting all necessary studies, including safety studies and clinical trials necessary in connection with seeking regulatory approvals to market the product in any territory. If ImmunityBio requires nanatinostat, the Company has the right to manufacture nanatinostat to be sold as part of a therapeutic product utilizing nanatinostat at a transfer price related to Viracta’s cost to ImmunityBio. In accordance with the NK Agreement, the Company is also eligible to receive up to a total of $ 100.0 million in milestone payments, with respect to the licensed products. The Company is eligible to earn tiered royalties on net sales of licensed products by ImmunityBio, its affiliates or sublicensees, ranging from the low to mid-single digits. The Company has recognized no revenue from milestones (variable consideration), which are fully constrained, or royalties to date. Unless earlier terminated, the NK Agreement will continue until the expiration of all applicable royalty terms on a product-by-product and country-by-country basis. There are no performance, cancellation, termination, or refund provisions in the arrangement that contain material financial consequences to the Company.

Financial Statement Details

Financial Statement Details	12 Months Ended
	Dec. 31, 2021
Financial Statement Details [Abstract]
Financial Statement Details	4. Financial Statement Details Accrued expenses consist of the following (in thousands): December 31, 2021 2020 Accrued payroll and benefits $ 1,695 $ 1,501 Accrued clinical trial and contract expenses 3,380 1,095 Accrued professional services and expenses 180 716 Other accrued expenses 547 50 Total accrued expenses $ 5,802 $ 3,362

XOMA Transaction

XOMA Transaction	12 Months Ended
	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
XOMA Transaction	5. XOMA Transaction On March 22, 2021, the Company entered into a Royalty Purchase Agreement with XOMA (US) LLC (“XOMA”), in which XOMA purchased the potential future milestones and royalties associated with existing licenses relating to two clinical-stage product candidates, DAY101 and vosaroxin, which were obtained in the Merger (the “XOMA Transaction”). The Company received an upfront payment of $ 13.5 million and may receive up to $ 20.0 million in a pre-commercialization, event-based milestone. The upfront payment is nonrefundable, there are no clawback provisions, and the Company has no significant involvement or obligations going forward related to potential future milestones and royalties. The Company has recognized no income from the pre-commercialization, event-based milestone to date. In December 2019, Sunesis entered into a license agreement with DOT Therapeutics-1, LLC (“DOT-1”) to grant DOT-1 a worldwide, exclusive license of DAY101. The DOT-1 license agreement includes up to $ 57.0 million in potential pre-commercialization, event-based milestone payments and royalty payments on future sales of DAY101, when and if approved and commercialized, $ 3.0 million of which was received by Sunesis prior to the XOMA Transaction. Also in December 2019, Sunesis entered into an agreement to license vosaroxin to Denovo Biopharma LLC, which includes up to $ 57.0 million in potential regulatory and commercial milestones, and double-digit royalties on future sales of vosaroxin, when and if approved and commercialized. The potential milestone and royalty payments related to DAY101 and vosaroxin were sold in the XOMA Transaction.

Debt

Debt	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Debt	6. Debt Loan Agreement On July 30, 2020, Private Viracta and Silicon Valley Bank (the “Lender”) entered into a loan and security agreement (the “SVB Loan Agreement”), providing for up to $ 15.0 million in four tranches. Upon entering into the SVB Loan Agreement, Private Viracta borrowed $ 5.0 million. The loan was due on the scheduled maturity date of July 1, 2024 and had an interest only period through January 31, 2022, followed by 30 equal monthly payments of principal plus accrued interest commencing on February 1, 2022. The per annum interest rate for any outstanding loan was the lesser of (i) 10 %, or (ii) the greater of (A) 3.5 % above the prime rate or (B) 6.75 %. The interest rate as of December 31, 2020 was 6.75 % per annum. In addition, a final payment of 7.0 % of the amount of the loan drawn was due on the earlier of the Maturity Date, acceleration of the loan, or prepayment of the loan. The final payment was accrued through interest expense using the effective interest method. The debt issuance costs and warrants issued (Note 8) were accounted for as a debt discount. The debt discount was being amortized as interest expense over the term of the loan using the effective interest method. If the Company elected to prepay the loan, a prepayment fee equal to 1 % or 2 % of the then outstanding principal balance was also due, depending upon when the prepayment occurs. No prepayment fee is charged if the credit is replaced with a new facility from the same bank. On November 4, 2021, the Company entered into a new loan and security agreement with SVB and Oxford (the “Loan Agreement”) for up to $ 50.0 million. In connection with entering the new $ 50.0 million credit facility, the Company and SVB agreed to terminate the Company’s prior $ 15.0 million loan and security agreement with SVB. The existing $ 5.0 million debt balance from the Company’s previous credit facility with SVB was relieved under this new $ 50.0 million credit facility. The Loan Agreement was accounted for as a modification based on the effect of changes in terms from the original SVB Loan Agreement. Under the terms of the $ 50.0 million credit facility, the remaining $ 45.0 million is available in two additional tranches of $ 20.0 million and $ 25.0 million under certain circumstances, and the Company is under no obligation to draw funds in the future. The loan will be due on the scheduled maturity date of November 1, 2026 (the “Maturity Date”). In accordance with the original terms of the Loan Agreement, repayment of the loan is interest only through December 31, 2023, and, upon completion of the certain milestones, the interest only period would be extended through December 31, 2024. This period of interest only will be followed by 35 equal monthly payments of principal plus accrued interest commencing on January 1, 2024, or if the milestone is achieved, the period of interest only will be followed by 23 equal monthly payments of principal plus accrued interest commencing on January 1, 2025. The per annum interest rate for any outstanding loan is equal to the greater of (i) 8.15 % and (ii) the sum of (a) the Prime Rate, as reported in The Wall Street Journal on the last business day of the month that immediately precedes the month in which the interest will accrue, plus (b) 4.90 %. In addition, a final payment of 5.0 % of the amount of the loan drawn will be due on the earlier of the Maturity Date, acceleration of the loan, or prepayment of the loan. The final payment is being accrued through interest expense using the effective interest method. If the Company elects to prepay the loan, a prepayment fee equal to 1 % or 2 % of the then outstanding principal balance will also be due, depending upon when the prepayment occurs. If the Company elects to not draw certain portions of the loan, the Company will incur a 3 % fee of the undrawn portion. The Company is subject to customary affirmative and restrictive covenants under the Loan Agreement. The Company’s obligations under the Loan Agreement are secured by a first priority security interest in substantially all of its current and future assets, other than the Company's intellectual property. The Company has also agreed not to encumber its intellectual property assets, except as permitted by the Loan Agreement. The Loan Agreement also contains customary indemnification obligations and customary events of default, including, among other things, the Company’s failure to fulfill certain obligations under the Loan Agreement and the occurrence of a material adverse change in the Company’s business, operations, or condition (financial or otherwise), a material impairment of the prospect of repayment of any portion of the loan, or a material impairment in the perfection or priority of Lender’s lien in the collateral or in the value of such collateral. In the event of default by the Company under the Loan Agreement, the Lender would be entitled to exercise their remedies thereunder, including the right to accelerate the debt, upon which the Company may be required to repay all amounts then outstanding under the Loan Agreement. As of December 31, 2021, the Company was in compliance with all financial covenants under the Loan Agreement and there had been no material adverse change. The debt issuance costs are being accounted for as a debt discount. The debt discount is being amortized as interest expense over the term of the loan using the effective interest method. The carrying value of the debt approximates the fair value (Level 2) as of December 31, 2021. The following table summarizes future principal payments (in thousands) under the terms of the Loan Agreement: Year Ending December 31, 2022 $ — 2023 — 2024 1,714 2025 1,714 Thereafter 1,572 Total future principal payments 5,000 Unamortized discount ( 181 ) Total, net $ 4,819 Paycheck Protection Program Loan On April 24, 2020, Viracta received loan proceeds of $ 0.3 million from First Republic Bank, as lender, pursuant to the Payment Protection Program (“PPP”) of the CARES Act (the “PPP Loan”). The maturity date of the PPP Loan was April 23, 2022 , with a per annum interest rate of 1.0 %. The PPP Loan was evidenced by a promissory note dated April 23, 2020, which contained customary events of default relating to, among other things, payment defaults and breaches of representations and warranties. The PPP Loan could have been prepaid by the Company at any time prior to maturity with no prepayment penalties. All or a portion of the PPP Loan was potentially eligible for forgiveness by the U.S. Small Business Administration (“SBA”) upon the Company’s application and upon documentation of expenditures in accordance with the SBA requirements. Under the CARES Act and PPP Flexibility Act, loan forgiveness was available for the sum of documented payroll costs, covered mortgage interest, covered rent payments and covered utilities during the 24-week period beginning on the date of loan disbursement. In the event the PPP Loan, or any portion thereof, was forgiven pursuant to the PPP, the amount forgiven would be applied to outstanding principal and would include accrued interest. The Company used all proceeds from the PPP Loan to retain employees, maintain payroll and make lease and utility payments, and sought forgiveness in accordance with the program in late 2020. In June 2021, the Company received notification from the SBA that the Company's Forgiveness Application of the PPP Loan and accrued interest, totaling $ 0.3 million, was approved in full and the Company had no further obligations related to the PPP Loan. Accordingly, the Company recorded a gain on the forgiveness of the PPP Loan for the year ended December 31, 2021.

Merger

Merger	12 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Merger	7. Merger The Merger, which closed on February 24, 2021, was accounted for as a reverse asset acquisition pursuant to Topic 805, Business Combinations , as substantially all of its fair value was concentrated in cash, working capital, and IPR&D. As the IPR&D assets had no alternative future use, the fair value attributable to these assets was recorded as acquired IPR&D in the Company’s consolidated statements of operations for the year ended December 31, 2021. The estimated fair value of total consideration given was $ 103.4 million based on 5,173,772 shares of Sunesis common stock and 10,248 shares of Sunesis convertible preferred stock (or 292,799 Sunesis common shares on an as-converted basis) outstanding immediately prior to the merger date. The number of outstanding common stock and preferred stock on an as-converted basis was multiplied by the Sunesis closing common stock price of $ 18.62 on the date of the merger, plus transaction costs of approximately $ 1.6 million, to determine the estimated fair value of total consideration. The allocation of the purchase price is as follows (in thousands): Net assets acquired (1) $ 18,956 Acquired IPR&D (2) 84,478 Purchase price $ 103,434 (1) Net assets acquired (in thousands): Cash and cash equivalents $ 17,143 Prepaid expenses and other assets 3,768 Accounts payable and accrued liabilities ( 1,955 ) Net assets acquired $ 18,956 (2) Represents the research and development projects of Sunesis which were in-process, but not yet completed. Current accounting standards require that the fair value of IPR&D projects acquired in an asset acquisition with no alternative future use be allocated a portion of the consideration transferred and charged to expense on the acquisition date. The acquired IPR&D assets did not have outputs or employees.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2021
Stockholders' Equity Note [Abstract]
Stockholders' Equity	8. Stockholders’ Equity Common Stock The total number of shares of common stock of Viracta outstanding as of December 31, 2021 and December 31, 2020 was 37,424,863 and 905,987 , respectively. Concurrent Financing On February 24, 2021, immediately prior to the closing of the Merger, the Company completed the February 2021 private placement offering of an aggregate of 12,012,369 shares of common stock for gross proceeds of $ 65.0 million and incurred fees and other offering costs of approximately $ 2.7 million. Sales Agreement On May 28, 2021, the Company entered into an Open Market Sale Agreement SM (the “Sale Agreement”) with Jefferies LLC (the “Sales Agent”), under which the Company may offer and sell up to $ 50.0 million shares (the “Shares”) of its common stock, par value $ 0.0001 per share (“Common Stock”), from time to time through the Sales Agent. The sales and issuances, if any, of the Shares by the Company under the Sale Agreement will be pursuant to the Company’s registration statement on Form S-3 (the “Registration Statement”), filed with the SEC on May 28, 2021 and declared effective by the SEC on June 4, 2021. Sales, if any, of the Shares pursuant to the Sale Agreement may be made in negotiated transactions or transactions that are deemed to be “at the market offerings” as defined in Rule 415(a)(4) promulgated under the Securities Act of 1933, as amended, including sales made directly on The Nasdaq Stock Market, or sales made into any other existing trading market for the Common Stock. The Sales Agent is not required to sell any specific amount of securities, but will act as the Company’s sales agent using commercially reasonable efforts to sell the Shares from time to time, consistent with its normal trading and sales practices, applicable state and federal laws, rules and regulations and the rules of The Nasdaq Stock Market, based upon instructions from the Company (including any price, time or size limits or other customary parameters or conditions the Company may impose). As of December 31, 2021 , the Company has incurred legal and accounting costs of $ 0.1 million related to the Sales Agreement. As of December 31, 2021 , no shares had been issued pursuant to the Sales Agreement. Convertible Preferred Stock On November 25, 2020, the Company completed a Series E Preferred Stock equity financing, issuing 7,392,240 shares at a price per share of $ 5.41 , which yielded gross proceeds of approximately $ 40.0 million. The Series E Preferred Stock was convertible into common stock at any time prior to the Merger. The number of shares of common stock that will be issued upon such conversion is determined by dividing its original issuance price by the applicable conversion price. Liquidation Preference The outstanding shares would have been entitled to certain liquidation preferences according to their agreements, in the event of any liquidation, dissolution, or winding up of the Company, either voluntary or involuntary. Series E Preferred Stock held liquidation preference priority over Series D Preferred Stock, Series C Preferred Stock, Series B Preferred Stock and Series A-1 Preferred Stock. Series D Preferred Stock held liquidation preference priority over Series C Preferred Stock, Series B Preferred Stock and Series A-1 Preferred Stock. Series C Preferred Stock held liquidation preference priority over both Series B Preferred Stock and Series A-1 Preferred Stock. Series B Preferred Stock held priority over Series A-1 Preferred Stock. If, upon the occurrence of such event, the proceeds distributed among the holders of the Series E Preferred Stock, the Series D Preferred Stock, the Series C Preferred Stock, the Series B Preferred Stock, and the Series A-1 Preferred Stock would have been insufficient to permit the full payment of the aforementioned preferential amounts to each holder of convertible preferred stock, then the entire proceeds legally available for distribution to the convertible preferred stock would have been distributed ratably among the holders of the Series E Preferred Stock, Series D Preferred Stock, Series C Preferred Stock, the Series B Preferred Stock, and the Series A-1 Preferred Stock in proportion to the full preferential amount that each such holder of convertible preferred stock was otherwise entitled to receive. Upon completion of the distributions required by the above-mentioned liquidation preferences, any remaining proceeds would have been distributed among the holders of Series E Preferred Stock, Series D Preferred Stock, Series C Preferred Stock, Series B Preferred Stock, Series A-1 Preferred Stock and common stock pro rata based on the number of shares of common stock held by each, assuming full conversion of the Series E Preferred Stock, Series D Preferred Stock, Series C Preferred Stock, the Series B Preferred Stock, and the Series A-1 Preferred Stock, to common stock at the then-effective conversion price for such shares. Dividends The holders of shares of Series E Preferred Stock, Series D Preferred Stock, Series C Preferred Stock, Series B Preferred Stock, and Series Preferred Stock would have been entitled to receive dividends, out of any assets legally available, prior and in preference to any declaration or payment of any dividend on the common stock, in an amount at least equal to 8 % per annum of the Series E original issue price, Series D original issue price, Series C original issue price, the Series B original issue price and the Series A-1 original issue price, respectively, all subject to adjustment from time to time for recapitalizations, payable when and if declared by the Company’s board of directors. The Company did no t declared any dividends on its convertible preferred stock. Voting The holder of each share of Series E Preferred Stock, Series D Preferred Stock, Series C Preferred Stock, Series B Preferred Stock and Series A-1 Preferred Stock would have been entitled to one vote for each share of common stock into which such preferred stock could then be converted and, with respect to such vote, such holder had full voting rights and powers equal to the voting rights and powers of the holders of common stock and would have been entitled to notice of any stockholders’ meeting in accordance with the Company’s bylaws. The Company was a party to a voting agreement with certain holders of its capital stock. The parties to the voting agreement had agreed, subject to certain conditions, to vote the shares of the Company’s capital stock held by them so as to elect the following individuals as directors: (1) two individuals designated by the holders of a majority of the outstanding shares of Series A-1 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock and Series D Preferred Stock, (2) one individual who is an industry expert designated by the holders of a majority of the outstanding shares of Series A-1 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock and Series D Preferred Stock, voting together as a single class and on an as-converted to Common Stock basis, (3) one individual designated by certain Series E holder, so long as that holder owns any shares of Series E Preferred Stock, (4) one individual designated by the holders of a majority of the outstanding shares of Series E Preferred Stock, (5) one individual who is an industry expert designated by the holders of a majority the outstanding shares of Series E Preferred Stock, and (6) the Company’s Chief Executive Officer. Upon the consummation of the merger with Sunesis Pharmaceuticals, Inc., the obligations of the parties to the voting agreement to vote its shares so as to elect these nominees, as well as the other rights and obligations under this agreement, terminated and none of the Company’s stockholders have any special rights regarding the nomination, election or designation of members of the combined company’s board of directors. Redemption The Company’s convertible preferred stock were not explicitly redeemable or at a specified date in the future. The convertible preferred stock were presented outside of stockholders’ equity because in the event of certain deemed liquidation events considered not solely within the Company’s control, such as a merger, acquisition and sale of all or substantially all of the Company’s assets, the convertible preferred stock were redeemable at the option of the holders. As these deemed liquidation events were not probable of occurring, the Company did not adjust the carrying values of the convertible preferred stock. Automatic Conversion - Merger Upon the closing of a sale of shares of common stock in a public offering, all outstanding shares of Series A-1 Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock were automatically converted into shares of common stock at the then effective conversion price, given that (a) the offering results in gross proceeds to the Company of at least $ 40.0 million before underwriting discount and commissions, and (b) the shares of common stock were listed for trading on the NASDAQ Global Market. In connection with the closing of the merger and the concurrent private placement of common stock, the holders of the Company’s preferred stock waived their right to exchange their shares into any class of stock other than common and converted to common stock immediately prior to the closing of the concurrent private placement of common stock. In connection with the Merger, all of the outstanding shares of Private Viracta’s convertible preferred stock were converted into 18,811,552 shares of the Company’s common stock. As of December 31, 2020, Private Viracta’s convertible preferred stock was classified as temporary equity on the accompanying consolidated balance sheets in accordance with authoritative guidance for the classification and measurement of potentially redeemable securities whose redemption is based upon certain change in control events outside of Private Viracta’s control, including liquidations, sale or transfer of control of Private Viracta. Private Viracta did not adjust the carrying values of the convertible preferred stock to the liquidation preferences of such shares because the occurrence of any such change of control event was not deemed probable. With the Merger, the Company obtained 10,000,000 shares of authorized preferred stock available for future issuance in one or more series. Upon issuance, the Company can determine the rights, preferences, privileges and restrictions thereof. These rights, preference and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number of shares constituting any series or the designation of such series, any or all of which may be greater than the rights of common stock. There were 10,248 shares of this preferred stock outstanding as of December 31, 2021 , of which 1,915 shares were Series E Stock and 8,333 shares were Series F Stock. The Series E Stock and Series F Stock are non-voting Series E and Series F Convertible Preferred Stock at a stated price of $ 500 and $ 600 per share, respectively. Each share of non-voting Series E Stock and Series F Stock is convertible at a conversion ratio equal to the stated price divided by the conversion price, which is $ 17.50 per share and $ 21.00 per share, respectively, provided that conversion will be prohibited if, as a result, the holder and its affiliates would own more than 9.98 % of the total number of shares of common stock then outstanding. In the event of the Company’s liquidation, dissolution, or winding up, holders of Series E and Series F Stock will receive a payment before any proceeds are distributed to the holders of Common Stock. Shares of Series E and Series F Stock will generally have no voting rights, except as required by law and except that the consent of holders of a majority of this outstanding Series E Stock will be required to amend the terms of the Series E and Series F Stock. Shares of the Series E and Series F Stock will not be entitled to receive any dividends, unless and until specifically declared by the Company’s board of directors, and will rank: • senior to all of the Company’s Common Stock; • senior to any class or series of the Company’s capital stock hereafter created specifically ranking by its terms junior to the Series E and Series F Stock; • on parity with any class or series of the Company’s capital stock hereafter created specifically ranking by its terms on parity with the Series E and Series F Stock; and • junior to any class or series of the Company’s capital stock hereafter created specifically ranking by its terms senior to the Series E and Series F Stock; in each case, as to distributions of assets upon the Company’s liquidation, dissolution or winding up whether voluntarily or involuntarily. Warrants Concurrent with the issuance of convertible promissory notes in 2018, the Company issued to the note investors warrants to purchase 250,323 shares of Viracta Common Stock (the “Common Warrants”). The Common Warrants’ exercise price was $ 0.09 per share. Unless previously exercised, the Common Warrants will expire on the seven-year anniversary of the date of issuance. As of December 31, 2021, Common Warrants to purchase 86,209 shares of Viracta Common Stock remain unexercised. These shares have been included in the weighted average shares outstanding for both basic and diluted earnings per share for the years ended December 31, 2021 and 2020 as their exercise price is for nominal consideration. In July 2020, the Company issued warrants exercisable for 206,440 pre-merger shares of Series E preferred stock, at a pre-merger exercise price of $ 0.6055 per share, to Silicon Valley Bank in conjunction with the Company’s entry into the SVB Loan Agreement (the “Lender Warrants”). Upon completion of the Merger, the Lender Warrants became exercisable for 23,100 shares of common stock at an exercise price of $ 5.42 per share. The Lender Warrants will expire on July 30, 2030. Common Stock Reserved for Future Issuance Common stock reserved for future issuance are as follows in common equivalent shares: December 31, 2021 2020 Conversion of preferred stock 292,799 18,811,552 Common stock warrants 109,309 193,266 Preferred stock warrants — 23,100 Stock options issued and outstanding for all plans 4,051,572 1,127,842 RSUs outstanding 745,668 — Authorized for future option grants 1,169,523 1,108,809 Common stock authorized for the ESPP 60,948 — Total 6,429,819 21,264,569 Equity Incentive Plans In January 2017, the Company adopted the Viracta Therapeutics, Inc. 2016 Equity Incentive Plan (the “2016 Plan”), which permitted stock option and restricted stock unit grants to employees, members of the board of directors, and outside consultants. The Plan allowed for grants of incentive stock options with exercise prices of at least 100 % of the fair market value of Viracta’s common stock, nonqualified options with exercise prices of at least 85 % of the fair market value of the Company’s common stock, restricted stock, and restricted stock units. All stock options granted under the 2016 Plan have a ten-year life and generally vest over zero to four years . In connection with the closing of the Merger, no further awards will be made under the 2016 Plan but the 2016 Plan will continue to govern the terms and conditions of the outstanding awards previously granted under the 2016 Plan. At the time of the close of the Merger, the Company adopted the Viracta Therapeutics, Inc. 2021 Equity Incentive Plan (the “2021 Plan”), which also permits stock options and restricted stock unit grants to employees, members of the board of directors, and outside consultants. The maximum number of shares of the Company’s common stock available for issuance under the 2021 Plan equals the sum of (a) 2,628,571 shares; (b) any shares of common stock of the Company which are subject to awards under the Sunesis 2011 Equity Incentive Plan (the “Sunesis 2011 Plan”) or the 2016 Plan as of the effective date of the 2021 Plan which become available for issuance under the 2021 Plan after such date in accordance with its terms; and (c) an annual increase on the first day of each calendar year beginning with January 1 of the calendar year following the effectiveness of the 2021 Plan and ending with the last January 1 during the initial ten year term of the 2021 Plan. This annual increase would be equal to the lesser of (i) 3,771,428 shares, (ii) five percent of the number of shares of the Company’s common stock outstanding (on an as-converted basis) on the final day of the immediately preceding calendar year, and (iii) such number of shares of the Company’s common stock as determined by the Company’s board of directors. The 2021 Plan allows for grants of incentive stock options with exercise prices of at least 100 % of the fair market value of Viracta’s common stock, nonqualified options with exercise prices of at least 100 % of the fair market value of the Company’s common stock, restricted stock, and restricted stock units. All stock options granted to date have a ten-year life and generally vest over zero to four years . Additionally, in connection with the closing of the Merger, no further awards will be made under the Sunesis 2011 Plan. As of December 31, 2021, 88,019 fully vested options remain outstanding under the Sunesis 2011 Plan with a weighted average exercise price of $ 27.65 per share. The share-based compensation recorded in the accompanying consolidated statements of operations for the years ending December 31, 2021 and 2020 is presented below (in thousands): Year Ended December 31, 2021 2020 Research and development $ 2,122 $ 158 General and administrative 3,420 190 Total $ 5,542 $ 348 On June 30, 2021, the Company adopted the 2021 Inducement Equity Incentive Plan (the “2021 Inducement Plan”) and reserved 1,000,000 shares for future grant under the 2021 Inducement Plan. As of December 31, 2021 , there were 715,000 shares available for issuance under the 2021 Inducement Plan. Stock Options The Company recorded share-based compensation related to stock options of $ 4.8 million and $ 0.3 million for the year ended December 31, 2021 and 2020, respectively. Fair value is determined on the date of grant for options. Compensation expense is recognized over the vesting period based on the fair value of the options. The fair value of stock options is estimated using the Black-Scholes model with the assumptions disclosed in the following table: Year Ended December 31, 2021 2020 Risk free interest rate 0.66 % - 1.33 % 0.46 % - 0.87 % Expected option term 5.8 - 6.3 years 5.5 - 6.3 years Expected volatility of common stock 84.15 % - 90.20 % 72.13 % - 90.20 % Expected dividend yield 0 % 0 % The expected term of stock options is based on the simplified method, which is an average of the contractual term of the option and its vesting period. The expected volatility of stock options is based upon the historical volatility of a number of publicly traded companies in similar stages of clinical development. The risk-free interest rate is based on the average yield of U.S. Treasury Bills appropriate for the expected term of the stock option grants. The Company has not historically paid cash dividends and does not anticipate declaring dividends in the future. As of December 31, 2021 , unrecognized compensation expense related to unvested options granted totaled $ 17.3 million. The expense is expected to be recognized over a weighted-average period of 3.0 years. A summary of the stock option activity under the 2016 Plan and the 2021 Plan during the period ended December 31, 2021 is presented below (in thousands except for per share and weighted average term): Number of Weighted Weighted Aggregate Intrinsic Value Outstanding at December 31, 2020 1,128 $ 1.08 8.5 $ 2,827 Granted 3,223 $ 8.82 Exercised ( 301 ) $ 0.98 $ 8 Cancelled ( 86 ) $ 3.23 $ 154 Outstanding at December 31, 2021 3,964 $ 7.33 8.9 $ 1,973 Outstanding at December 31, 2021 (Sunesis 2011 Plan) 88 $ 27.65 3.4 $ — Vested and exercisable at December 31, 2021 852 $ 7.39 7.8 $ 829 The intrinsic values of the above represent the aggregate value of the total pre-tax intrinsic value based upon a common stock price of $ 3.65 and $3 .58 at December 31, 2021 and 2020, respectively, and the contractual exercise price. The weighted average grant date fair value per share of employee stock options granted during the years ended December 31, 2021 and 2020 was $ 6.25 and $ 1.64 , respectively. Restricted Stock Units The Company recorded share-based compens ation related to RSUs of $ 0.7 million for the year ended December 31, 2021. There were no RSUs granted prior to 2021. For RSU equity awards, grant date fair value is estimated using the closing stock price on the date of grant. Compensation expense is recognized over the vesting period based on the fair value of the RSUs. A summary of the restricted stock unit activity under the plans during the period ended December 31, 2021 is presented below (in thousands except for per share and weighted average term): RSUs Weighted Weighted Outstanding at December 31, 2020 — $ — — Granted 852 4.22 Vested ( 107 ) 4.22 Cancelled — — Outstanding at December 31, 2021 745 $ 4.22 3.4 As of December 31, 2021 , unrecognized compensation expense related to unvested RSUs totaled $ 2.7 million. The expense is expected to be recognized over a weighted-average period of 3.4 years. Employee Stock Purchase Plan The Company adopted the 2011 Employee Stock Purchase Plan (the “2011 ESPP”) as part of the Merger. The 2011 ESPP permits eligible employees to purchase common stock at a discount through payroll deductions during defined offering periods. Eligible employees can purchase shares of the Company’s common stock at 85 % of the lower of the fair market value of the common stock at (i) the beginning of a 12-month offering period, or (ii) at the end of one of the two related 6-month purchase periods. No participant in the 2011 ESPP may be issued or transferred shares of common stock value at more than $ 25,000 per calendar year. As of December 31, 2021 , there were 60,948 shares available for future issuance under the 2011 ESPP.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases In 2018, the Company negotiated a one-year lease for its office (“Lease”). The effective date of the Lease was September 1, 2018. Under the terms of the Lease the rental rate was $ 14,132 per month. In June 2019, the Company amended the term of the Lease to extend the termination date to August 31, 2020 . Under the terms of the Lease amendment, the rental rate was $ 14,980 per month. Upon the Lease amendment, the Company no longer met the short-term lease exemption and recorded an operating lease right-of-use (“ROU”) asset and corresponding lease liability for $ 225,000 . In June 2020, the Company amended the Lease and another existing office lease to enter into a noncancelable operating lease to extend the lease term through August 2023 with a renewal option for an additional year (“Amended Lease”). The Amended Lease monthly base rent will increase approximately 4 % annually from $ 20,019 to $ 21,444 over the life of the lease, including utilities and other operating costs. Upon the execution of the Amended Lease, the Company recorded an operating lease ROU asset and corresponding lease liability for $ 667,000 . In August 2020, the Company entered into an additional noncancelable operating lease agreement for certain office space with a lease term from August 2020 through August 2023 with a renewal option for an additional year (“New Lease”). The New Lease also includes a buyout option to terminate the lease prior to its expiration with at least one month’s prior written notice and a one-time payment equal to four months’ rent. The New Lease monthly base rent will increase approximately 4 % to 9 % from $ 12,462 to $ 14,033 over the life of the lease, including utilities and other operating costs. In connection with the execution of the New Lease, the Company recorded an operating lease ROU asset and corresponding lease liability for $ 439,000 . The following table summarizes future minimum payments under the term loan facility as of December 31, 2021 (in thousands): Year Ending December 31, 2022 $ 416 2023 284 2024 — 2025 — Thereafter — Total lease payments 700 Less: imputed interest ( 41 ) Total operating lease liabilities $ 659 Total lease expense for the years ended December 31, 2021 and 2020 was $ 608,000 and $ 297,000 , respectively. At December 31, 2021, the Company had remaining lease liabilities of approximately $ 659,000 of which $ 278,000 was recorded as noncurrent lease liability as of December 31, 2021, and operating lease ROU assets of $ 640,000 . Total cash paid for amounts included in the measurement of operating lease liabilities was $ 546,000 and $ 343,000 for the years ended December 31, 2021 and 2020, respectively. As of December 31, 2021 and 2020, the weighted average discount rate for the operating leases was 8.0 % for both periods, and the weighted average remaining lease term was 1.6 years as of December 31, 2021 . There were no new or amended lease arrangements executed in 2021. Indemnifications As permitted under Delaware law, the Company indemnifies its officers, directors, and employees for certain events and occurrences while the officer, or director is, or was, serving at the Company’s request in such capacity.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes As a result of the Company’s significant operating loss carryforwards and the corresponding valuation allowance, no income tax provision/benefit has been recorded as of December 31, 2021 and 2020. Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2021 and 2020 are detailed below (in thousands). Years Ended December 31, 2021 2020 Deferred tax assets: Federal and state net operating loss carryforwards $ 37,319 $ 18,617 Federal and California research and development credit carryforwards 6,674 3,899 Share-based compensation expense 701 76 Capitalized 59(e) Expenses and Amortization 4,804 2,276 Other, net 107 218 Total deferred tax assets 49,605 25,086 ROU asset ( 134 ) ( 207 ) Total deferred tax liabilities ( 134 ) ( 207 ) Net deferred tax asset 49,471 24,879 Valuation allowance ( 49,471 ) ( 24,879 ) Net deferred tax liability $ — $ — The Company’s effective income tax rate differs from the statutory federal rate of 21 % for the years ended December 31, 2021 and 2020 due to the following: Years Ended December 31, 2021 2020 % % Federal statutory rate 21 21 State tax benefit, net of federal benefit 7 — Valuation allowance ( 9 ) ( 20 ) General business credits 3 11 Acquired IPR&D ( 21 ) — State rate true up — ( 5 ) Other ( 1 ) ( 7 ) Effective income tax rate — — At December 31, 2021, the Company had federal and state net operating loss carryforwards of $ 147.5 million and $ 105.3 million, respectively. The federal loss carryforwards begin to expire in 2027 , unless previously utilized, and the state carryforwards begin to expire in 2030 . The Company has federal loss carryforwards of $ 107.2 million that are not subject to expiration. The Company also has federal and state research credit carryforwards of $ 1.5 million and $ 1.8 million, respectively. Additionally the Company has Orphan Drug Credit carryforwards of $ 7.3 million. The federal research credit carryforwards will begin expiring in 2027 , unless previously utilized. The state research credit will carry forward indefinitely. The change in the valuation allowance is an increase of $ 24.6 million and $ 3.8 million for the years ended December 31, 2021 and December 31, 2020, respectively. Pursuant to Internal Revenue Code (“IRC”) Sections 382 and 383, annual use of the Company’s net operating loss and research and development credit carryforwards may be limited in the event a cumulative change in ownership of more than 50% occurs within a three-year period. The Company has not completed an IRC Section 382/383 analysis regarding the limitation of net operating loss and research and development credit carryforwards and these financial statements do not contain any adjustment relating to such potential limitations. Due to the existence of the valuation allowance, future changes in the Company’s net operating loss and research and development credit carryforwards will not impact the Company’s effective tax rate. In accordance with authoritative guidance, the impact of an uncertain income tax position is recognized at the largest amount that is “more likely than not” to be sustained upon audit by the relevant taxing authority. An uncertain tax position will not be recognized if it has less than a 50% likelihood of being sustained. The following table summarizes the activity related to the Company’s unrecognized tax benefits (in thousands): Years Ended December 31, 2021 2020 Gross unrecognized tax benefits at the beginning of the year $ 3,971 $ 1,952 Additions based on tax positions related to the current year 991 709 Additions for tax positions of prior years — 1,310 Gross unrecognized tax benefits at the end of the year $ 4,962 $ 3,971 The amount of the unrecognized tax benefits that would impact the effective tax rate, absent the valuation allowance, would be $ 4.5 million. Due to the full valuation allowance, the future changes in unrecognized tax benefits will not impact the Company’s effective tax rate. At December 31, 2021, the Company has no t accrued any interest or penalties related to uncertain tax positions. The Company does no t anticipate that there will be a significant change in the amount of unrecognized tax benefits over the next twelve months. The Company recognizes interest and penalties related to uncertain tax positions in income tax expense. The Company is subject to taxation in the U.S. and California. Due to the existence of net operating loss carryforwards, all tax periods from inception of the Company are open for examination by taxing authorities for all jurisdictions. The Company is not currently under examination by any tax authority.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	11. Subsequent Events For the purposes of the consolidated financial statements as of December 31, 2021 and for the year ended, the Company has evaluated subsequent events through the date the audited annual consolidated financial statements were issued. The Company has concluded that no subsequent event has occurred that required disclosure in the consolidated financial statements other than what has been disclosed.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries and have been prepared in accordance with GAAP. All intercompany balances and transactions have been eliminated upon consolidation.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that 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 amounts of expenses during the reporting period. Actual results could differ materially from those estimates.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash and cash equivalents.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity from the date of purchase of three months or less to be cash equivalents.
Property and Equipment	Property and Equipment Property and equipment, which consisted of office equipment, were stated at cost and depreciated over the estimated useful lives of the assets (three to five years) using the straight-line method. Leasehold improvements were amortized over the shorter of their estimated useful lives or the lease term.
Leases	Leases The Company classifies leases as either operating or finance leases at inception and as necessary at modification. Leased assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. The Company does not obtain and control its right to use the identified asset until the lease commencement date. Operating leases are included in operating lease right-of-use (“ROU”) assets, and operating lease liabilities on the Company’s balance sheets. Operating lease ROU assets and liabilities are recognized at lease commencement date based on the present value of lease payments over the lease term. When readily determinable, the Company uses the rate implicit in the lease to discount lease payments; however, when the rate is not readily determinable, the Company uses the incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The incremental borrowing rate is the rate of interest that the Company would have to pay to borrow an amount equal to the lease payments on a collateralized basis over a similar term and in a similar economic environment. The operating lease ROU asset also includes any initial direct costs, lease payments made prior to lease commencement, and lease incentives received. Variable lease payments are expensed as incurred and are not included within the ROU asset and lease liability calculation. The Company’s lease terms are the noncancelable period and may include options to extend the lease when it is reasonably certain that it will exercise that option. Lease cost for lease payments is recognized on a straight-line basis over the lease term. The Company does not separate lease and non-lease components. The Company does not recognize ROU assets and lease liabilities for short-term leases, which have a lease term of twelve months or less and do not include an option to purchase the underlying asset that the Company is reasonably certain to exercise. Lease cost for short-term leases is recognized on a straight-line basis over the lease term.
Revenue Recognition	Revenue Recognition Revenue is recognized when control of the promised goods or services is transferred to the Company’s customers in an amount that reflects the consideration the Company expects to receive from its customers in exchange for those goods and services. This process involves identifying the contract with a customer, determining the performance obligations in the contract, determining the transaction price, allocating the contract price to the distinct performance obligations in the contract, and recognizing revenue when or as the Company satisfies the performance obligation(s). At contract inception, the Company assesses the goods and services promised within each contract and assesses whether each promised good or service is distinct and determines that those are performance obligations. A performance obligation is considered distinct from other obligations in a contract when it provides a benefit to the customer either on its own or together with other resources that are readily available to the customer and is separately identified in the contract. The Company considers factors such as the research, manufacturing and commercialization capabilities of the collaboration partner and the availability of the associated expertise in the general marketplace. The Company considers a performance obligation satisfied once the Company has transferred control of a good or service to the customer, meaning the customer has the ability to use and obtain the benefit of the good or service. The Company recognizes revenue for satisfied performance obligations only when the Company determines there are no uncertainties regarding payment terms or transfer of control. Collaborative Arrangements The Company evaluates collaboration arrangements to determine whether units of account within the collaboration arrangement exhibit the characteristics of a vendor and customer relationship. For arrangements and units of account where a customer relationship exists, the Company applies the revenue recognition guidance. The Company enters into collaborative arrangements with partners that may include payment to the Company of one or more of the following: (i) license fees; (ii) payments related to the achievement of developmental, regulatory, or commercial milestones; and (iii) royalties on net sales of licensed products. If a contract has multiple performance obligations, the Company allocates the transaction price to each distinct performance obligation in an amount that reflects the consideration the Company is entitled to receive in exchange for satisfying each distinct performance obligation. For each distinct performance obligation, revenue is recognized when (or as) the Company transfers control of the product or the service applicable to such performance obligation. The Company evaluates each performance obligation to determine if it can be satisfied at a point in time or over time. In addition, variable consideration must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price. License Fees If a license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from upfront fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. Milestone Payments At the inception of each arrangement that includes milestone payments (variable consideration), the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price. If it is probable that a milestone event would occur at the inception of the arrangement, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each reporting period, the Company evaluates the probability of achievement of such milestones and any related constraint(s), and if necessary, may adjust the Company’s estimate of the overall transaction price. To date, the Company has not recognized any milestone revenue resulting from its collaborative arrangements. Royalties For arrangements that include sales-based royalties, including milestone payments based on the level of sales, the Company recognizes revenue when the related sales occur. To date, the Company has not recognized any royalty revenue resulting from its collaborative arrangements.
Clinical Trial and Contracts Accruals	Clinical Trial and Contracts Accruals The Company accrues clinical trial costs based on work performed. In determining the amount to accrue, the Company relies on estimates of total costs incurred based on enrollment, the completion of clinical trials and other events. The Company follows this method because it is believed to be reasonably dependable estimates of the costs applicable to various stages of a clinical trial can be made. However, the actual costs and timing of clinical trials are highly uncertain, subject to risks and may change depending on a number of factors. Differences between the actual clinical trial costs and the estimated clinical trial costs that have been accrued in any prior period are recognized in the subsequent period in which the actual costs become known. Historically, estimated accrued expenses have approximated actual expenses incurred; however, material differences could occur in the future.
Research and Development Expenses	Research and Development Expenses Research and development costs are expensed as incurred. These costs consist primarily of salaries and other personnel-related expenses, including share-based compensation; facility-related expenses; and services performed by clinical research organizations, research institutions, and other outside service providers. The Company makes estimates of its accrued expenses as of each balance sheet date in the consolidated financial statements based on facts and circumstances known to us at that time. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly. This process involves reviewing contract and purchase orders, reviewing the terms of vendor agreements, communicating with applicable personnel to identify services that have been performed on the Company's behalf and estimating the level of service performed and the associated cost incurred for the services when it has not yet been invoiced or otherwise notified of actual cost. The majority of the Company's service providers invoice monthly in arrears for services performed.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. This approach requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of the differences between the tax basis of assets or liabilities and their carrying amounts in the consolidated financial statements using the enacted tax rates and laws that are anticipated to be in effect when the differences are expected to reverse. The Company provides a valuation allowance against net deferred tax assets if it is more likely than not that these items will either expire before the Company is able to realize their benefit or if future deductibility is uncertain. In accordance with the accounting standards for uncertain tax positions, the Company evaluates the recognition threshold and measurement attribute criteria for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by taxing authorities.
Share-Based Compensation	Share-Based Compensation The Company accounts for share-based compensation expense related to stock options granted to employees, members of the board of directors, and outside consultants by estimating the fair value of each stock option on the date of grant using the Black-Scholes option pricing model. The Company accounts for restricted stock units (“RSUs”) by determining the fair value of each restricted stock unit based on the closing market price of the common stock on the date of grant. The Company recognizes share-based compensation on a straight-line basis over the requisite service period of the stock-based award, and forfeitures are recognized as they occur. The estimate of fair value for share-based compensation for stock options requires management to make estimates and judgments about, among other things, employee exercise behavior and volatility of the Company’s common stock. The judgments directly affect the amount of compensation expense that will be recognized.
Segment Reporting	Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is used in making decisions regarding resource allocation and assessing performance. To date, the Company has viewed its operations and managed its business as one segment operating in the United States. All long-lived assets were located in the United States at December 31, 2021 and December 31, 2020.
Fair Value Measurements	Fair Value Measurements The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or non-recurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market- based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets. Level 2: Inputs, other than the quoted prices in active markets that are observable either directly or indirectly. Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. The carrying amounts of the Company’s cash and cash equivalents, prepaid expenses, accounts payable and accrued liabilities approximate fair values for these financial instruments due to their short maturities. The money market funds, classified as cash equivalents, are Level 1 and had an amortized cost and estimated fair value of $ 14.9 million as of December 31, 2021. The Company had no money market funds prior to 2021. The preferred st ock warrant liability, a level 3 fair value measurement, was $ 0 a s of December 31, 2021 , due to the reclassification to equity, and $ 106,000 as of December 31, 2020. The Company had no liabilities measured at fair value on a recurring basis as of December 31, 2021 . The Company had no assets or liabilities measured at fair value on a recurring basis as of December 31, 2020, other than the preferred stock warrant liability.
Preferred Stock Warrant Liability	Preferred Stock Warrant Liability The assumptions used in the Black-Scholes option pricing model to determine the fair value of the preferred stock warrant liability were as follows: February 24, 2021 Expected volatility 90.2 % Risk-free interest rate 1.38 % Expected dividend yield 0 % Expected term 9.3 years Fair value per share of preferred stock $ 17.15 The following table provides a reconciliation of the preferred stock warrant liability measured at fair value using Level 3 significant unobservable inputs (in thousands): Preferred Stock Balance at December 31, 2020 $ 106 Change in fair value of preferred stock warrant liability 290 Reclassification to equity ( 396 ) Balance at December 31, 2021 $ —
Net Loss Per Share	Net Loss Per Share Basic loss per common share is computed by dividing net loss by the weighted average number of common shares and warrants to purchase common stock for nominal consideration outstanding during the period. Diluted loss per common share is computed by dividing net loss by the weighted average number of common shares outstanding, plus the impact of common shares, if dilutive, resulting from the exercise of outstanding common stock equivalents. For all periods presented, there is no difference in the number of shares used to compute basic and diluted shares outstanding due to the Company's net loss position. The following securities are excluded from the calculation of weighted average dilutive common shares because their inclusion would have been anti-dilutive: December 31, 2021 2020 Shares issuable upon conversion of preferred stock 292,799 18,811,552 Common stock options and RSUs outstanding 4,797,240 1,127,842 Warrants to purchase preferred stock — 23,100 Warrants to purchase common stock 23,100 — Total excluded securities 5,113,139 19,962,494
Recently Accounting Pronouncements	Recently Adopted Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt – Debt with Conversion and Other options (Subtopic 470-20) and Derivative and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40) . The amendments in this ASU reduce the number of accounting models for convertible debt instruments and convertible preferred stock, as well as amend the guidance for the derivatives scope exception for contracts in an entity’s own equity to reduce form-over-substance-based accounting conclusions. In addition, this ASU improves and amends the related earnings per share guidance. The amendments in this ASU are effective for the Company on January 1, 2024, including interim periods within those fiscal years. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. Adoption is either a modified retrospective method or a fully retrospective method of transition. The Company early adopted ASU 2020-06 on January 1, 2021, electing the modified retrospective transition method that allows for a cumulative-effect adjustment in the period of adoption. The adoption of ASU 2020-06 did not have a material impact on the Company’s consolidated financial statements. In October 2021, the FASB issued ASU No. 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers. The amendment requires acquiring entities to apply Topic 606 to recognize and measure contract assets and contract liabilities in a business combination. The ASU will be effective for the Company for the annual periods beginning after December 15, 2022, with early adoption permitted. The Company early adopted ASU 2021-08 in the fourth quarter of 2021 with no material impact on its consolidated financial statements. Recently Issued Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board or other standard setting bodies that the Company will adopt as of the specified effective date. The Company has evaluated recently issued accounting pronouncements and as a result, based on the Company's preliminary assessment, do not believe any will have a material impact on the consolidated financial statements or related footnote disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of Fair Value Measurement Inputs and Valuation Techniques	The assumptions used in the Black-Scholes option pricing model to determine the fair value of the preferred stock warrant liability were as follows: February 24, 2021 Expected volatility 90.2 % Risk-free interest rate 1.38 % Expected dividend yield 0 % Expected term 9.3 years Fair value per share of preferred stock $ 17.15
Summary of reconciliation of warrant liability measured at fair value	The following table provides a reconciliation of the preferred stock warrant liability measured at fair value using Level 3 significant unobservable inputs (in thousands): Preferred Stock Balance at December 31, 2020 $ 106 Change in fair value of preferred stock warrant liability 290 Reclassification to equity ( 396 ) Balance at December 31, 2021 $ —
Summary of antidilutive securities excluded from the calculation of weighted average dilutive common shares	The following securities are excluded from the calculation of weighted average dilutive common shares because their inclusion would have been anti-dilutive: December 31, 2021 2020 Shares issuable upon conversion of preferred stock 292,799 18,811,552 Common stock options and RSUs outstanding 4,797,240 1,127,842 Warrants to purchase preferred stock — 23,100 Warrants to purchase common stock 23,100 — Total excluded securities 5,113,139 19,962,494

Financial Statement Details (Ta

Financial Statement Details (Tables)	12 Months Ended
	Dec. 31, 2021
Financial Statement Details [Abstract]
Schedule of Accrued Liabilities	Accrued expenses consist of the following (in thousands): December 31, 2021 2020 Accrued payroll and benefits $ 1,695 $ 1,501 Accrued clinical trial and contract expenses 3,380 1,095 Accrued professional services and expenses 180 716 Other accrued expenses 547 50 Total accrued expenses $ 5,802 $ 3,362

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Summary of Future Minimum Payments Under Loan Facility	The following table summarizes future principal payments (in thousands) under the terms of the Loan Agreement: Year Ending December 31, 2022 $ — 2023 — 2024 1,714 2025 1,714 Thereafter 1,572 Total future principal payments 5,000 Unamortized discount ( 181 ) Total, net $ 4,819

Merger (Tables)

Merger (Tables)	12 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Summary of Allocation of the Purchase Price To Assets and Liabilities Acquired	The allocation of the purchase price is as follows (in thousands): Net assets acquired (1) $ 18,956 Acquired IPR&D (2) 84,478 Purchase price $ 103,434 (1) Net assets acquired (in thousands): Cash and cash equivalents $ 17,143 Prepaid expenses and other assets 3,768 Accounts payable and accrued liabilities ( 1,955 ) Net assets acquired $ 18,956 (2) Represents the research and development projects of Sunesis which were in-process, but not yet completed. Current accounting standards require that the fair value of IPR&D projects acquired in an asset acquisition with no alternative future use be allocated a portion of the consideration transferred and charged to expense on the acquisition date. The acquired IPR&D assets did not have outputs or employees.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2021
Stockholders' Equity Note [Abstract]
Shares of Common Stock Reserved for Future Issuance	Common stock reserved for future issuance are as follows in common equivalent shares: December 31, 2021 2020 Conversion of preferred stock 292,799 18,811,552 Common stock warrants 109,309 193,266 Preferred stock warrants — 23,100 Stock options issued and outstanding for all plans 4,051,572 1,127,842 RSUs outstanding 745,668 — Authorized for future option grants 1,169,523 1,108,809 Common stock authorized for the ESPP 60,948 — Total 6,429,819 21,264,569
Summary of Shared Based Compensation Cost Included in Consolidated Statement of Operations	The share-based compensation recorded in the accompanying consolidated statements of operations for the years ending December 31, 2021 and 2020 is presented below (in thousands): Year Ended December 31, 2021 2020 Research and development $ 2,122 $ 158 General and administrative 3,420 190 Total $ 5,542 $ 348
Summary of fair value of stock options is estimated using the Black-Scholes model	The fair value of stock options is estimated using the Black-Scholes model with the assumptions disclosed in the following table: Year Ended December 31, 2021 2020 Risk free interest rate 0.66 % - 1.33 % 0.46 % - 0.87 % Expected option term 5.8 - 6.3 years 5.5 - 6.3 years Expected volatility of common stock 84.15 % - 90.20 % 72.13 % - 90.20 % Expected dividend yield 0 % 0 %
Summary of Stock Option Activity for Company's Stock Option Plans	A summary of the stock option activity under the 2016 Plan and the 2021 Plan during the period ended December 31, 2021 is presented below (in thousands except for per share and weighted average term): Number of Weighted Weighted Aggregate Intrinsic Value Outstanding at December 31, 2020 1,128 $ 1.08 8.5 $ 2,827 Granted 3,223 $ 8.82 Exercised ( 301 ) $ 0.98 $ 8 Cancelled ( 86 ) $ 3.23 $ 154 Outstanding at December 31, 2021 3,964 $ 7.33 8.9 $ 1,973 Outstanding at December 31, 2021 (Sunesis 2011 Plan) 88 $ 27.65 3.4 $ — Vested and exercisable at December 31, 2021 852 $ 7.39 7.8 $ 829 The intrinsic values of the above represent the aggregate value of the total pre-tax intrinsic value based upon a common stock price of $ 3.65 and $3 .58 at December 31, 2021 and 2020, respectively, and the contractual exercise price. The weighted average grant date fair value per share of employee stock options granted during the years ended December 31, 2021 and 2020 was $ 6.25 and $ 1.64 , respectively.
Summary of Restricted Stock Units Activity	A summary of the restricted stock unit activity under the plans during the period ended December 31, 2021 is presented below (in thousands except for per share and weighted average term): RSUs Weighted Weighted Outstanding at December 31, 2020 — $ — — Granted 852 4.22 Vested ( 107 ) 4.22 Cancelled — — Outstanding at December 31, 2021 745 $ 4.22 3.4

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Rental Payments For Operating Leases Table Text Block	The following table summarizes future minimum payments under the term loan facility as of December 31, 2021 (in thousands): Year Ending December 31, 2022 $ 416 2023 284 2024 — 2025 — Thereafter — Total lease payments 700 Less: imputed interest ( 41 ) Total operating lease liabilities $ 659

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of Deferred Tax Assets and Liabilities	Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2021 and 2020 are detailed below (in thousands). Years Ended December 31, 2021 2020 Deferred tax assets: Federal and state net operating loss carryforwards $ 37,319 $ 18,617 Federal and California research and development credit carryforwards 6,674 3,899 Share-based compensation expense 701 76 Capitalized 59(e) Expenses and Amortization 4,804 2,276 Other, net 107 218 Total deferred tax assets 49,605 25,086 ROU asset ( 134 ) ( 207 ) Total deferred tax liabilities ( 134 ) ( 207 ) Net deferred tax asset 49,471 24,879 Valuation allowance ( 49,471 ) ( 24,879 ) Net deferred tax liability $ — $ —
Schedule of Effective Income Tax Rate	The Company’s effective income tax rate differs from the statutory federal rate of 21 % for the years ended December 31, 2021 and 2020 due to the following: Years Ended December 31, 2021 2020 % % Federal statutory rate 21 21 State tax benefit, net of federal benefit 7 — Valuation allowance ( 9 ) ( 20 ) General business credits 3 11 Acquired IPR&D ( 21 ) — State rate true up — ( 5 ) Other ( 1 ) ( 7 ) Effective income tax rate — —
Schedule of Unrecognized Tax Benefits	The following table summarizes the activity related to the Company’s unrecognized tax benefits (in thousands): Years Ended December 31, 2021 2020 Gross unrecognized tax benefits at the beginning of the year $ 3,971 $ 1,952 Additions based on tax positions related to the current year 991 709 Additions for tax positions of prior years — 1,310 Gross unrecognized tax benefits at the end of the year $ 4,962 $ 3,971

Organization and Basis of Pre_2

Organization and Basis of Presentation - Additional Information (Detail) $ in Thousands	Feb. 24, 2021	Feb. 28, 2021USD ($)	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)	Nov. 04, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Accumulated deficit				$ (165,677)		$ (50,915)
Cash and cash equivalents		$ 17,100		103,554		$ 47,089	$ 18,218
Working capital				96,200
Gross proceeds from private placement		65,000
Reverse stock split	3.5-for-one
Percentage of outstanding common stock of combined company	86.00%
Conversion ratio	0.1119
Line of credit maximum borrowing amount					$ 50,000
Line of Credit Facility, Remaining Borrowing Capacity					45,000
Silicon Valley Bank ("SVB") [Member]
Line of credit maximum borrowing amount					50,000
Silicon Valley Bank ("SVB") and Oxford Finance LLC ("Oxford") [Member]
Line of credit maximum borrowing amount					50,000
Line of Credit Facility, Current Borrowing Capacity					5,000
Line of Credit Facility, Remaining Borrowing Capacity					$ 45,000
Royalty Purchase Agreement [member]
Upfront payment received			$ 13,500	$ 13,500
Private Placement [Member]
Gross proceeds from private placement		$ 65,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Summary of Fair Value Measurement Inputs and Valuation Techniques (Detail) - Preferred Stock Warrant Liability [Member]	Feb. 24, 2021UsDollarsShareyr
Measurement Input, Price Volatility [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants and Rights Outstanding, Measurement Input	90.2
Measurement Input, Risk Free Interest Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants and Rights Outstanding, Measurement Input	1.38
Measurement Input, Expected Dividend Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants and Rights Outstanding, Measurement Input	0
Measurement Input, Expected Term [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants and Rights Outstanding, Measurement Input | yr	9.3
Measurement Input, Share Price [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants and Rights Outstanding, Measurement Input | UsDollarsShare	17.15

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Reconciliation of Warrant Liability Measured at Fair Value (Detail) - Preferred Stock Warrant Liability [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Opening , Balance	$ 106
Change in fair value of preferred stock warrant liability	290
Reclassification to equity	(396)
Ending , Balance	$ 0

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2021USD ($)Segment	Dec. 31, 2020USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on recurring basis	$ 0
Common Stock Warrant Liability		$ 0
Preferred stock warrant liability noncurrent	$ 0	106,000
United States [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of reportable segment | Segment	1
Fair Value, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Preferred stock warrant liability noncurrent	$ 0	106,000
Fair Value Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money Market Funds Fair Value	$ 14,900,000	$ 0

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Summary of Antidilutive Securities Excluded From the Calculation of Weighted Average Dilutive Common Shares (Detail) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	5,113,139	19,962,494
Shares issuable upon conversion of preferred stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	292,799	18,811,552
Common stock options and RSUs outstanding [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	4,797,240	1,127,842
Warrants to Purchase Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	23,100
Warrants to purchase common stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	23,100	0

Collaboration and License Agr_2

Collaboration and License Agreements - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Aug. 19, 2021	Dec. 31, 2021	Dec. 31, 2020	May 01, 2017
Collaboration and License Agreements [Line Items]
Acquired In Process Research And Development		$ 84,478	$ 0
Termination Agreement [Member]
Collaboration and License Agreements [Line Items]
Acquired In Process Research And Development	$ 4,000
Amount paid on the termination of agreement	$ 4,000
NK Agreement [Member]
Collaboration and License Agreements [Line Items]
Milestone payments to be received				$ 100,000

Financial Statement Details -

Financial Statement Details - Schedule of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued payroll and benefits	$ 1,695	$ 1,501
Accrued clinical trial and contract expenses	3,380	1,095
Accrued professional services and expenses	180	716
Other accrued expenses	547	50
Total accrued expenses	$ 5,802	$ 3,362

XOMA Transaction - Additional i

XOMA Transaction - Additional information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2019
Royalty Purchase Agreement [member]
Upfront payment received	$ 13.5	$ 13.5
Milestone payment received in the future		$ 20
DOT-1 License Agreement [Member] | License Agreement Terms [Member]
Potential pre-commercialization payments receivable			$ 57
Development milestone payment received			3
Denovo License Agreement [Member] | License Vosaroxin [Member]
Regulatory, commercial milestones payments and double-digit royalty payments, receivable			$ 57

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($) $ in Thousands	Nov. 04, 2021	Apr. 24, 2020	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Jul. 30, 2020
Debt [Line Items]
Line of credit maximum borrowing amount	$ 50,000
Line of credit facility remaining	45,000
Tranche One [Member]
Debt [Line Items]
Line of credit facility remaining	20,000
Tranche Two [Member]
Debt [Line Items]
Line of credit facility remaining	25,000
SVB Loan Agreement [Member]
Debt [Line Items]
Debt Instrument, Face Amount				$ 5,000
Payment Protection Program Loan [Member]
Debt [Line Items]
Debt Instrument, Maturity Date		Apr. 23, 2022
Debt Instrument, Interest Rate		1.00%
Debt Instrument, Increase (Decrease), Net			$ 300
Debt and Lease Obligation				$ 0
Silicon Valley Bank [Member] | Maximum [Member]
Debt [Line Items]
Prepayment Fee Percentage				2.00%
Silicon Valley Bank [Member] | Minimum [Member]
Debt [Line Items]
Prepayment Fee Percentage				1.00%
First Republic Bank [Member] | Payment Protection Program Loan [Member]
Debt [Line Items]
Proceeds from Long-term Lines of Credit		$ 300
Silicon Valley Bank ("SVB") and Oxford Finance LLC ("Oxford") [Member]
Debt [Line Items]
Line of credit maximum borrowing amount	50,000
Line of credit facility remaining	45,000
Silicon Valley Bank ("SVB") [Member]
Debt [Line Items]
Line of credit maximum borrowing amount	50,000
Repayments of Long-term Lines of Credit	5,000
Silicon Valley Bank ("SVB") [Member] | Contract Termination [Member]
Debt [Line Items]
Termination of Loan and Security agreement	$ 15,000
Term Loan Agreement [Member] | Silicon Valley Bank [Member]
Debt [Line Items]
Line of credit maximum borrowing amount						$ 15,000
Debt Instrument, Maturity Date				Nov. 1, 2026
Debt Instrument, Interest Rate				4.90%
Debt Instrument Final Payment Interest Fee Percentage				5.00%
Fee incurred for undrawn portion of loan				3.00%
Term Loan Agreement [Member] | Silicon Valley Bank [Member] | Prime Rate [Member]
Debt [Line Items]
Debt Instrument, Interest Rate During Period				8.15%
Term Loan Agreement [Member] | Silicon Valley Bank ("SVB") [Member] | SVB Loan Agreement [Member]
Debt [Line Items]
Debt Instrument, Maturity Date				Jul. 1, 2024
Debt Instrument, Interest Rate					6.75%
Debt Instrument Final Payment Interest Fee Percentage				7.00%
Prepayment Fee Percentage				0.00%
Term Loan Agreement [Member] | Silicon Valley Bank ("SVB") [Member] | Prime Rate [Member] | SVB Loan Agreement [Member]
Debt [Line Items]
Debt Instrument, Interest Rate				6.75%
Term Loan Agreement [Member] | Silicon Valley Bank ("SVB") [Member] | Maximum [Member] | SVB Loan Agreement [Member]
Debt [Line Items]
Debt Instrument, Interest Rate				10.00%
Prepayment Fee Percentage				2.00%
Term Loan Agreement [Member] | Silicon Valley Bank ("SVB") [Member] | Minimum [Member] | SVB Loan Agreement [Member]
Debt [Line Items]
Prepayment Fee Percentage				1.00%
Term Loan Agreement [Member] | Silicon Valley Bank ("SVB") [Member] | Minimum [Member] | Prime Rate [Member] | SVB Loan Agreement [Member]
Debt [Line Items]
Debt Instrument, Interest Rate				3.50%

Debt - Summary of Future Minimu

Debt - Summary of Future Minimum Payments Under Loan Facility (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
2022	$ 0
2023	0
2024	1,714
2025	1,714
Thereafter	1,572
Total Future minimum payments	5,000
Unamortized discount	(181)
Total, net	$ 4,819	$ 4,155

Merger - Additional Information

Merger - Additional Information (Detail) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021USD ($)$ / sharesshares
Business Acquisition [Line Items]
Estimated Fair value of total consideration | $	$ 103.4
Transaction costs | $	$ 1.6
Common Stock [Member]
Business Acquisition [Line Items]
Number of shares of common stock outstanding prior to the merger date	5,173,772
Shares issuable upon conversion of preferred stock [Member]
Business Acquisition [Line Items]
Number of shares of convertible preferred stock outstanding prior to merger	10,248
Common Stock Convertible Basis [Member]
Business Acquisition [Line Items]
Number of shares of Common stock as a convertible basis outstanding prior to merger	292,799
Sunesis Pharmaceuticals Inc [Member]
Business Acquisition [Line Items]
Share price | $ / shares	$ 18.62

Merger - Summary of Allocation

Merger - Summary of Allocation of the Purchase Price To Assets and Liabilities Acquired (Detail) $ in Thousands	Dec. 31, 2021USD ($)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Net assets acquired	$ 18,956
Acquired IPR&D	84,478
Purchase price	103,434
Net assets acquired
Cash and cash equivalents	17,143
Prepaid expenses and other assets	3,768
Accounts payable and accrued liabilities	(1,955)
Net assets acquired	$ 18,956

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	May 28, 2021	Feb. 24, 2021	Nov. 25, 2020	Jan. 01, 2020	Jan. 31, 2017	Dec. 31, 2021	Dec. 31, 2020	Jul. 30, 2020	Dec. 31, 2019
Stockholders Equity [Line Items]
Common stock, shares outstanding						37,424,863	905,987
Price per common share			$ 5.41			$ 3.65	$ 0.58
Convertible Preferred Stock, Shares Issued upon Conversion			7,392,240				18,811,552
Preferred stock, shares authorized						10,000,000
Preferred stock, shares outstanding						10,248
Weighted average grant date fair value per share						$ 6.25	$ 1.64
Underwriting discount and commissions						$ 40,000,000
Share Issued						0
Redemption Premium			$ 40,000,000
Convertible Preferred Stock, Nonredeemable or Redeemable, Issuer Option, Value						$ 0
Share of common stock value						$ 25,000
Preferred Stock, Dividend Rate, Percentage						8.00%
Weighted average exercise price						$ 7.33	$ 1.08
Stock reserved for future grant						6,429,819	21,264,569
Stock-based compensation						$ 5,542,000	$ 348,000
Stock option plan weighted average vesting period						8 years 10 months 24 days	8 years 6 months
Twenty Thousand and Sixteen Equity Incentive Plan [Member]
Stockholders Equity [Line Items]
Options granted period						10 years
2021 Equity Incentive Plan [Member]
Stockholders Equity [Line Items]
Stock Options Granted						10 years
Common stock available for issuance automatic increase period				10 years
Shares of common stock available for issuance				3,771,428		2,628,571
Shares Available for Future Grant						88,019
Purchase price of a share as a percentage of fair market value						100.00%
Percentage Of Nonqualified Options Exercisable Price Of Fair Market Value Of Common Stock						100.00%
Weighted average exercise price						$ 27.65
Percentage of outstanding common stock						5.00%
2021 Inducement Plan [Member]
Stockholders Equity [Line Items]
Shares of common stock available for issuance						715,000
Stock reserved for future grant						1,000,000
Stock Options [Member]
Stockholders Equity [Line Items]
Stock-based compensation						$ 4,800,000	$ 300,000
Stock option plan weighted average vesting period						3 years
Unrecognised compensation expense related to unvested units						$ 17,300,000
Incentive Stock Options [Member] | Twenty Thousand and Sixteen Equity Incentive Plan [Member]
Stockholders Equity [Line Items]
Percentage of exercise price fair value					100.00%
Nonqualified Options [Member] | Twenty Thousand and Sixteen Equity Incentive Plan [Member]
Stockholders Equity [Line Items]
Percentage of exercise price fair value					85.00%
Restricted Stock Units [Member]
Stockholders Equity [Line Items]
Stock reserved for future grant						745,668	0
Stock-based compensation						$ 700,000
Unrecognised compensation expense related to unvested units						$ 2,700,000
Restricted Stock units plan weighted average vesting period						3 years 4 months 24 days
Preferred Stock Warrants [Member]
Stockholders Equity [Line Items]
Stock reserved for future grant						0	23,100
Minimum [Member] | Twenty Thousand and Sixteen Equity Incentive Plan [Member]
Stockholders Equity [Line Items]
Options,vesting period						0 years
Maximum [Member]
Stockholders Equity [Line Items]
Stock Options Granted						4 years
Maximum [Member] | Twenty Thousand and Sixteen Equity Incentive Plan [Member]
Stockholders Equity [Line Items]
Options,vesting period						4 years
Series E and Series F Convertible Preferred Stock [Member]
Stockholders Equity [Line Items]
Percentage of outstanding common stock						9.98%
Shares issuable upon conversion of preferred stock [Member]
Stockholders Equity [Line Items]
Stock reserved for future grant						292,799	18,811,552
Series E Convertible Preferred Stock [Member]
Stockholders Equity [Line Items]
Price per common share						$ 500
Preferred stock, shares outstanding						1,915
Convertible share price per share						$ 17.50
Series F Convertible Preferred Stock [Member]
Stockholders Equity [Line Items]
Price per common share						$ 600
Preferred stock, shares outstanding						8,333
Convertible share price per share						$ 21
Warrant [Member] | Preferred Stock Warrants [Member]
Stockholders Equity [Line Items]
Class of warrant or right, exercise price of warrants or rights								$ 0.6055
Issue of warrants exercisable								206,440
Warrant [Member] | Preferred Stock Warrants [Member] | Silicon Valley Bank [Member]
Stockholders Equity [Line Items]
Class of warrant or right, exercise price of warrants or rights								$ 5.42
Issue of warrants exercisable								23,100
Warrant [Member] | Common Warrants [Member]
Stockholders Equity [Line Items]
Class of warrant or right issued in period of warrants or rights						250,323	250,323
Common Stock [Member]
Stockholders Equity [Line Items]
Share Issued						37,425,000	906,000		72,000
Stock issued during period						5,173,000
Stock Issued During Period, Shares, New Issues						12,012,000
Common Stock [Member] | Common Warrants [Member]
Stockholders Equity [Line Items]
Class of warrant or right, exercise price of warrants or rights						$ 0.09	$ 0.09
Class of warrant or right issued remain unexercised						86,209
Warrant expiration period						7 years
Employee Stock Purchase Plan [Member]
Stockholders Equity [Line Items]
Shares Available for Future Grant						60,948
Purchase price of a share as a percentage of fair market value						85.00%
Duration of offering period						12 months
Duration of each purchase period						6 months
Stock reserved for future grant						60,948	0
Private Placement [Member] | Common Stock [Member]
Stockholders Equity [Line Items]
Proceeds from issuance initial public offering		$ 65,000,000
Adjustments to additional paid in capital stock issuance costs		$ 2,700,000
Stock Issued During Period, Shares, New Issues		12,012,369
Sales Agreement [Member]
Stockholders Equity [Line Items]
Common stock par value	$ 0.0001
Legal and accounting cost						$ 100,000
Sales Agreement [Member] | Maximum [Member]
Stockholders Equity [Line Items]
Potential sales of common stock	$ 50,000,000

Stockholders' Equity - Shares o

Stockholders' Equity - Shares of Common Stock Reserved for Future Issuance (Detail) - shares	Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Total common stock reserved for future issuance	6,429,819	21,264,569
Authorized for future option grants [Member]
Class of Stock [Line Items]
Total common stock reserved for future issuance	1,169,523	1,108,809
Common stock warrants [Member]
Class of Stock [Line Items]
Total common stock reserved for future issuance	109,309	193,266
Preferred stock warrants [Member]
Class of Stock [Line Items]
Total common stock reserved for future issuance	0	23,100
Common stock authorized for the ESPP [Member]
Class of Stock [Line Items]
Total common stock reserved for future issuance	60,948	0
Stock options issued and outstanding for all plans [Member]
Class of Stock [Line Items]
Total common stock reserved for future issuance	4,051,572	1,127,842
RSUs outstanding [Member]
Class of Stock [Line Items]
Total common stock reserved for future issuance	745,668	0
Convertible preferred stock [Member]
Class of Stock [Line Items]
Total common stock reserved for future issuance	292,799	18,811,552

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Shared Based Compensation Cost Included in Consolidated Statement of Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Cost Included in Condensed Statement Of Operations [Line Items]
Total stock-based compensation expense	$ 5,542	$ 348
Research and development [Member]
Share Based Compensation Cost Included in Condensed Statement Of Operations [Line Items]
Total stock-based compensation expense	2,122	158
General and administrative [Member]
Share Based Compensation Cost Included in Condensed Statement Of Operations [Line Items]
Total stock-based compensation expense	$ 3,420	$ 190

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Fair Value of Stock Options is Estimated Using the Black-Scholes Model (Detail)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%	0.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest rate	0.66%	0.46%
Expected option term	5 years 9 months 18 days	5 years 6 months
Expected volatility of common stock	84.15%	72.13%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk free interest rate	1.33%	0.87%
Expected option term	6 years 3 months 18 days	6 years 3 months 18 days
Expected volatility of common stock	90.20%	90.20%

Stockholders' Equity - Summar_3

Stockholders' Equity - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Outstanding, Beginning Balance, Number of Shares	1,128
Outstanding, Beginning Balance, Weighted Average Exercise Price Per Share	$ 1.08
Options granted , Numbers of Shares	3,223
Vested and exercisable	852
Outstanding, Intrinsic Value	$ 1,973	$ 2,827
Options granted, Weighted Average Exercise Price Per Share	$ 8.82
Options exercised , Numbers of Shares	(301)
Exercised, Aggregate Intrinsic Value	$ 8
Options exercised, Weighted Average Exercise Price Per Share	$ 0.98
Options Cancelled , Number of Shares	(86)
Weighted Average Exercise Price, Vested and excercise	$ 7.39
Options Cancelled , Weighted average exercise price	$ 3.23
Vested and exercisable, Aggregate Intrinsic Value	$ 829
Outstanding, Ending Balance, Number of Shares	3,964	1,128
Cancelled, Aggregate Intrinsic Value	$ 154
Outstanding ending balance, Aggregate Intrinsic Value	$ 1,973	$ 2,827
Outstanding, Ending Balance, Weighted Average Exercise Price Per Share	$ 7.33	$ 1.08
Outstanding, Weighted Average Remaining Contractual Term (Years)	8 years 10 months 24 days	8 years 6 months
Vested and exercisable, Weighted Average Remaining Contractual Term (Years)	7 years 9 months 18 days
2011 Plan [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Outstanding, Ending Balance, Number of Shares	88
Outstanding, Ending Balance, Weighted Average Exercise Price Per Share	$ 27.65
Outstanding, Weighted Average Remaining Contractual Term (Years)	3 years 4 months 24 days

Stockholders' Equity - Summar_4

Stockholders' Equity - Summary of Restricted Stock Units Activity (Detail) shares in Thousands	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Share-based Payment Arrangement [Abstract]
RSUs, Beginning balance | shares	0
RSUs, Granted | shares	852
RSUs, Vested | shares	107
RSUs, Cancelled | shares	0
RSUs, Ending balance | shares	745
Weighted Average Grant Date Fair Value per Share, Beginning balance | $ / shares	$ 0
Weighted Average Grant Date Fair Value per Share, Granted | $ / shares	4.22
Weighted Average Grant Date Fair Value per Share, Vested | $ / shares	4.22
Weighted Average Grant Date Fair Value per Share, Cancelled | $ / shares	0
Weighted Average Grant Date Fair Value per Share, Ending balance | $ / shares	$ 4.22
Weighted Average Remaining Contractual Term (Years)	3 years 4 months 24 days

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Income tax provision	$ 0	$ 0
Statutory income tax rate	21.00%	21.00%
Net valuation allowance, increased (decreased)	$ 24,600,000	$ 3,800,000
Orphan drug credit carryforwards	7,300,000
Unrecognized tax benefits that would have tax impact	4,500,000
Unrecognized tax benefits, interest and penalties accrued	0
Unrecognized tax benefits position will significantly change over the next twelve months	0
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carry-forwards	147,500,000
Research and development tax credit carry-forwards	$ 1,500,000
Net operating loss carry-forwards expiration	2027
Operating loss carryforwards, not subject to expiration	$ 107,200,000
Research credit carryforwards expiration start year	2027
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carry-forwards	$ 105,300,000
Research and development tax credit carry-forwards	$ 1,800,000
Net operating loss carry-forwards expiration	2030

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred Tax Assets, Net [Abstract]
Federal and state net operating loss carryforwards	$ 37,319	$ 18,617
Federal and California research and development credit carryforwards	6,674	3,899
Share-based compensation expense	701	76
Capitalized 59(e) Expenses and Amortization	4,804	2,276
Other, net	107	218
Total deferred tax assets	49,605	25,086
ROU asset	(134)	(207)
Total deferred tax liabilities	(134)	(207)
Net deferred tax assets before valuation allowance	49,471	24,879
Valuation allowance	(49,471)	(24,879)
Net deferred tax liability	$ 0	$ 0

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Federal statutory rate	21.00%	21.00%
State tax benefit, net of federal benefit	7.00%	0.00%
Valuation allowance	(9.00%)	(20.00%)
General business credits	3.00%	11.00%
Acquired IPR&D	(21.00%)	0.00%
State rate true up	0.00%	(5.00%)
Other	(1.00%)	(7.00%)
Effective income tax rate	0.00%	0.00%

Income Taxes - Schedule of Unre

Income Taxes - Schedule of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Gross unrecognized tax benefits at the beginning of the year	$ 3,971	$ 1,952
Additions based on tax positions related to the current year	991	709
Additions for tax positions of prior years	0	1,310
Gross unrecognized tax benefits at the end of the year	$ 4,962	$ 3,971

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($)	Aug. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2018
Loss Contingencies [Line Items]
Lease liability				$ 659,000
Operating lease right-of-use asset				640,000	$ 986,000
Operating Lease Expense				608,000	297,000
Lease liability noncurrent				278,000	658,000
Cash paid for operating lease liability				$ 546,000	$ 343,000
Operating lease weighted average discount rate				8.00%	8.00%
Operating lease weighted average remaining lease term				1 year 7 months 6 days
Option to extend the lease			option for an additional year
Description of lessee leasing arrangements new or amended				There were no new or amended lease arrangements executed in 2021.
Original Operating Lease [Member]
Loss Contingencies [Line Items]
Lease rental rate per month						$ 14,132
Lease Term						1 year
Lease extended termination description		term of the Lease to extend the termination date to August 31, 2020
Original Operating Lease Amended [Member]
Loss Contingencies [Line Items]
Lease rental rate per month		$ 14,980
Lease liability		225,000
Operating lease right-of-use asset		$ 225,000
Noncancelable operating lease agreement [Member] | Amended Operating Lease [Member]
Loss Contingencies [Line Items]
Lease liability			$ 667,000
Operating lease right-of-use asset			$ 667,000
Description of Lease Term			August 2023
Percentage of increase in monthly base rent			4.00%
Additional noncancelable operating lease agreement [Member] | New Operating Lease [Member]
Loss Contingencies [Line Items]
Lease liability	$ 439,000
Operating lease right-of-use asset	$ 439,000
Description of Lease Term	August 2020 through August 2023
Lease extended termination description	option to terminate the lease prior to its expiration with at least one month’s prior written notice and a one-time payment equal to four months’ rent.
Option to extend the lease	option for an additional year
Maximum [Member] | Noncancelable operating lease agreement [Member] | Amended Operating Lease [Member]
Loss Contingencies [Line Items]
Operating leases rent expense			$ 21,444
Maximum [Member] | Additional noncancelable operating lease agreement [Member] | New Operating Lease [Member]
Loss Contingencies [Line Items]
Lease rental rate per month	$ 14,033
Percentage of increase in monthly base rent	9.00%
Minimum [Member] | Noncancelable operating lease agreement [Member] | Amended Operating Lease [Member]
Loss Contingencies [Line Items]
Operating leases rent expense			$ 20,019
Minimum [Member] | Additional noncancelable operating lease agreement [Member] | New Operating Lease [Member]
Loss Contingencies [Line Items]
Lease rental rate per month	$ 12,462
Percentage of increase in monthly base rent	4.00%

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Payments for Operating Leases (Details)	Dec. 31, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
2022	$ 416,000
2023	284,000
2024	0
2025	0
Thereafter	0
Total lease payments	700,000
Less: imputed interest	(41,000)
Total operating lease liabilities	$ 659,000