Viracta Therapeutics (VIRX) 10-Q 7 May 20 2020 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	May 04, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Registrant Name	SUNESIS PHARMACEUTICALS 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		111,393,000
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	395 Oyster Point Boulevard
Entity Address, Address Line Two	Suite 400
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	650
Local Phone Number	266-3500
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	DE
Trading Symbol	SNSS
Title of 12(b) Security	Common Stock, $0.0001 par value
Security Exchange Name	NASDAQ

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents		$ 19,974	$ 12,761	[1]
Restricted cash		5,500	5,500	[1]
Marketable securities		3,445	16,364	[1]
Prepaids and other current assets		1,790	1,697	[1]
Total current assets		30,709	36,322	[1]
Property and equipment, net		1	3	[1]
Operating lease right-of-use asset		681	817	[1]
Other assets		96	98	[1]
Total assets		31,487	37,240	[1]
Current liabilities:
Accounts payable		862	791	[1]
Accrued clinical expense		600	521	[1]
Accrued compensation		746	985	[1]
Other accrued liabilities		1,039	1,109	[1]
Notes payable		5,469	5,465	[1]
Operating lease liability - current		545	545	[1]
Total current liabilities		9,261	9,416	[1]
Other liabilities		4	9	[1]
Operating lease liability - long term		136	272	[1]
Total liabilities		9,401	9,697	[1]
Commitments and contingencies				[1]
Stockholders’ equity:
Convertible preferred stock		11,769	11,769	[1]
Common stock		11	11	[1]
Additional paid-in capital		698,881	698,562	[1]
Accumulated other comprehensive income	[1]		1
Accumulated deficit		(688,575)	(682,800)	[1]
Total stockholders’ equity		22,086	27,543	[1]
Total liabilities and stockholders’ equity		$ 31,487	$ 37,240	[1]
[1]	The condensed consolidated balance sheet as of December 31, 2019, has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019.

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue:
License and other revenue	$ 120
Type of Revenue [Extensible List]	snss:LicenseAndOtherRevenueMember	snss:LicenseAndOtherRevenueMember
Operating expenses:
Research and development	$ 3,690	$ 3,248
General and administrative	2,228	2,439
Total operating expenses	5,918	5,687
Loss from operations	(5,798)	(5,687)
Interest expense	(70)	(261)
Other income, net	93	88
Net loss	(5,775)	(5,860)
Unrealized loss on available-for-sale securities	(1)
Comprehensive loss	(5,776)	(5,860)
Basic and diluted loss per common share:
Net loss	$ (5,775)	$ (5,860)
Shares used in computing net loss per common share	111,393	59,142
Net loss per common share	$ (0.05)	$ (0.10)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities
Net loss	$ (5,775)	$ (5,860)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	319	417
Accretion of investment discounts and depreciation	(37)	2
Amortization of debt discount and debt issuance costs	4	42
Changes in operating assets and liabilities:
Prepaids and other assets	(91)	(91)
Accounts payable	71	(532)
Accrued clinical expense	79	(80)
Accrued compensation	(239)	(266)
Other accrued liabilities	(75)	255
Net cash used in operating activities	(5,744)	(6,113)
Cash flows from investing activities
Purchases of marketable securities	(748)
Proceeds from maturities of marketable securities	13,705
Net cash provided by investing activities	12,957
Cash flows from financing activities
Principal payments on notes payable		(1,406)
Proceeds from issuance of convertible preferred stock offering, net		7,944
Proceeds from issuance of common stock, net		10,690
Net cash provided by financing activities		17,228
Net increase in cash, cash equivalents and restricted cash	7,213	11,115
Cash, cash equivalents and restricted cash at beginning of period	18,261	13,696
Cash, cash equivalents and restricted cash at end of period	$ 25,474	24,811
Supplemental disclosure of non-cash activities
Conversion of preferred stock to common stock		3,228
Right-of-use assets obtained in exchange for new operating lease liabilities		1,362
Legal expenses accrued as cost of equity financing		$ 98

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total		Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]
Beginning Balance at Dec. 31, 2018	$ 3,993		$ 20,998	$ 4	$ 642,460		$ (659,469)
Beginning Balance, shares at Dec. 31, 2018			18	37,474
Issuance of common and preferred stock in underwritten offering, net of issuance costs	18,536		$ 7,877	$ 2	10,657
Issuance of common and preferred stock in underwritten offering, net of issuance costs, shares			17	23,000
Conversion of preferred stock to common stock			$ (3,228)	$ 1	3,227
Conversion of preferred stock to common stock, shares			(7)	7,000
Issuance of common stock from vesting of restricted stock awards	54				54
Issuance of common stock from vesting of restricted stock awards, shares				104
Stock-based compensation expenses	363				363
Net loss	(5,860)						(5,860)
Ending Balance at Mar. 31, 2019	17,086		$ 25,647	$ 7	656,761		(665,329)
Ending Balance, shares at Mar. 31, 2019			28	67,578
Beginning Balance at Dec. 31, 2019	27,543	[1]	$ 11,769	$ 11	698,562	$ 1	(682,800)
Beginning Balance, shares at Dec. 31, 2019			20	111,393
Stock-based compensation expenses	319				319
Net loss	(5,775)						(5,775)
Unrealized loss on available-for-sale securities	(1)					$ (1)
Ending Balance at Mar. 31, 2020	$ 22,086		$ 11,769	$ 11	$ 698,881		$ (688,575)
Ending Balance, shares at Mar. 31, 2020			20	111,393
[1]	The condensed consolidated balance sheet as of December 31, 2019, has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019.

Company Overview

Company Overview	3 Months Ended
	Mar. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Company Overview	1. Company Overview Description of Business Sunesis Pharmaceuticals, Inc. (“Sunesis” or the “Company”) is a biopharmaceutical company focused on the development of novel targeted inhibitors for the treatment of hematologic and solid cancers. The Company’s primary activities since incorporation have been conducting research and development internally and through corporate collaborators, in-licensing and out-licensing pharmaceutical compounds and technology, conducting clinical trials, and raising capital. The Company’s lead program is vecabrutinib, a selective non-covalent inhibitor of Bruton’s Tyrosine Kinase (“BTK”) with activity against both wild-type and C481S-mutated BTK, the most common mutation associated with resistance to covalent BTK inhibitors. Ibrutinib was the first BTK inhibitor approved for the treatment of chronic lymphocytic leukemia (“CLL”), mantle cell lymphoma (“MCL”), and other B-cell malignancies. The C481 mutation has been seen in patients who developed resistance to ibrutinib and to acalabrutinib, another covalent BTK inhibitor recently approved for treatment of CLL and MCL. Vecabrutinib is being studied in a Phase 1b/2 clinical trial to assess safety and activity in patients with CLL and other advanced B-cell malignancies after two or more prior therapies, including ibrutinib or another covalent BTK inhibitor where approved for the disease. The Company has completed the safety evaluation period for the 400 mg cohort, and the seventh cohort, testing 500 mg twice daily, is now in process. The Company is developing SNS-510, a PDK1 inhibitor that it in-licensed from Millennium Pharmaceuticals, Inc. (“Takeda Oncology”), a wholly-owned subsidiary of Takeda Pharmaceutical Company Limited. SNS-510 interaction with PDK1 inhibits both PI3K signaling and PIP3-independent pathways integral to many malignancies, and PDK1 can also be overexpressed in breast, lung, prostate, hematologic and other cancers. In December 2019, the Company consented to Takeda Oncology’s assignment of TAK-580 to DOT Therapeutics-1, Inc. (“DOT-1”), and the Company entered into a license agreement with DOT-1 to grant DOT-1 a worldwide, exclusive license of TAK-580. Pursuant to this agreement, the Company received a $2.0 million upfront payment from DOT-1 and is eligible to receive up to $57.0 million in pre-commercialization, event-based milestone payments and royalty payments on future sales of TAK-580. In December 2019, Sumitomo Dainippon Pharma Co., Ltd. (“Sumitomo”) assigned to Sunesis worldwide rights to vosaroxin. The Company entered into an agreement (the “ Denovo License Agreement Liquidity and Going Concern The Company has incurred significant losses and negative cash flows from operations since its inception, and as of March 31, 2020, the Company had cash and cash equivalents, restricted cash, and marketable securities totaling $28.9 million and an accumulated deficit of $688.6 million. The Company expects to continue to incur significant losses for the foreseeable future as it continues development of its kinase inhibitor pipeline, including its BTK inhibitor, vecabrutinib. The Company has product candidates that are still in the early stages of development and will require significant additional investment. The Company’s cash and cash equivalents, restricted cash, and marketable securities are not sufficient to support its operations for a period of twelve months from the date these condensed consolidated financial statements are available to be issued. These factors raise substantial doubt about its ability to continue as a going concern. The Company will require additional financing to fund working capital, repay debt and pay its obligations as they come due. Additional financing might include one or more offerings and one or more of a combination of equity securities, debt arrangements or partnership or licensing collaborations. However, there can be no assurance that the Company will be successful in acquiring additional funding at levels sufficient to fund its operations or on terms favorable to the Company. If the Company is unsuccessful in its efforts to raise additional financing in the near term, the Company will be required to significantly reduce or cease operations. The principal payments due under the SVB Loan Agreement (as defined in Note 6) have been classified as a current liability as of March 31, 2020 due to the considerations discussed above and the assessment that the material adverse change clause under the SVB Loan Agreement is not within the Company's control. The SVB Loan Agreement also contains customary events of default, including among other things, the Company’s failure to make principal or interest payments when due, the occurrence of certain bankruptcy or insolvency events or its breach of the covenants under the SVB Loan Agreement. Upon the occurrence of an event of default (as defined in Note 6), SVB may, among other things, accelerate the Company’s obligations under the SVB Loan Agreement. The Company has not been notified of an event of default by SVB as of the date of the filing of this Form 10-Q. The accompanying condensed consolidated financial statements have been prepared assuming the Company will continue to operate as a going concern, which contemplates the realization of assets and the settlement of liabilities in the normal course of business. The condensed consolidated financial statements do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts of liabilities that may result from uncertainty related to the Company’s ability to continue as a going concern . Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk generally consist of cash and cash equivalents, restricted cash and marketable securities. The Company is exposed to credit risk in the event of default by the institutions holding its cash, cash equivalents, restricted cash and any marketable securities to the extent of the amounts recorded in the condensed consolidated balance sheets.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. The condensed consolidated financial statements include all adjustments (consisting only of normal recurring adjustments) that management believes are necessary for a fair presentation of the periods presented. The balance sheet as of December 31, 2019 was derived from the audited consolidated financial statements as of that date. These interim financial results are not necessarily indicative of results to be expected for the full year or any other period. These unaudited condensed consolidated financial statements and the notes accompanying them should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2019. Adopted Accounting Pronouncements In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement Recent Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments Financial Instruments—Credit Losses, Topic 326 Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842): Effective Dates Codification Improvements to Topic 326, Financial Instruments—Credit Losses, In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. . Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries, Sunesis Europe Limited, a United Kingdom corporation, and Sunesis Pharmaceuticals (Malta) Ltd., a Malta corporation. All intercompany balances and transactions have been eliminated in consolidation. Significant Estimates and Judgments The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the Company’s condensed consolidated financial statements and accompanying notes thereto. Actual results could differ materially from these estimates. Estimates, assumptions and judgments made by management include those related to valuation of marketable securities, equity and related instruments, revenue recognition, stock-based compensation and clinical trial accounting Cash Equivalents, Restricted Cash, and Marketable Securities The Company considers all highly liquid securities with original maturities of three months or less from the date of purchase to be cash equivalents, which generally consist of money market funds, repurchase agreements, and corporate debt securities. Restricted cash consists of amounts pledged as collateral for term loan agreement as contractually required by the lender. Marketable securities consist of securities with original maturities of greater than three months, which may include U.S. and European government obligations and corporate debt securities. Fair Value Measurements The Company measures cash equivalents at fair value on a recurring basis using the following hierarchy to prioritize valuation inputs, in accordance with applicable GAAP: Level 1 - Observable input such as quoted prices (unadjusted) in active markets for identical assets and liabilities that can be accessed at the measurement date; Level 2 - inputs other than quoted prices included within Level 1 that are observable, either directly or indirectly Level 3 - unobservable inputs The Company’s Level 2 valuations of marketable securities are generally derived from independent pricing services based upon quoted prices in active markets for similar securities, with prices adjusted for yield and number of days to maturity, or based on industry models using data inputs, such as interest rates and prices that can be directly observed or corroborated in active markets. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3, if any. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts of the Company’s financial instruments, including .

Loss per Common Share

Loss per Common Share	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Loss per Common Share	3. Loss per Common Share Basic loss per common share is calculated by dividing net loss by the weighted-average number of common shares outstanding for the period. Diluted loss per common share is computed by dividing (a) net loss, by (b) the weighted-average number of common shares outstanding for the period plus dilutive potential common shares as determined using the treasury stock method for options and warrants to purchase common stock. The following table represents the potential common shares issuable pursuant to outstanding securities as of the related period end dates that were excluded from the computation of diluted loss per common share because their inclusion would have had an anti-dilutive effect (in thousands): Three months ended March 31, 2020 2019 Warrants to purchase shares of common stock 208 218 Convertible preferred stock 19,714 16,331 Options to purchase shares of common stock 7,960 4,005 Outstanding securities not included in calculations 27,882 20,554

Financial Instruments

Financial Instruments	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Financial Instruments	4. Financial Instruments Financial Assets The following tables summarize the estimated fair value of the Company’s financial assets measured on a recurring basis as of the dates indicated, which are comprised solely of available-for-sale marketable securities with remaining contractual maturities of one year or less (in thousands): March 31, 2020 Input Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Money market funds Level 1 $ 19,050 $ — $ — $ 19,050 U.S. commercial paper Level 2 3,445 — — 3,445 Total available-for-sale securities 22,495 — — 22,495 Less amounts classified as cash equivalents (19,050 ) — — (19,050 ) Amounts classified as marketable securities $ 3,445 $ — $ — $ 3,445 December 31, 2019 Input Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Value Money market funds Level 1 $ 3,495 $ — $ — $ 3,495 U.S. Treasury securities Level 1 $ 1,594 $ 1 $ — $ 1,595 Repurchase agreements Level 2 $ 5,000 $ — $ — $ 5,000 U.S. corporate debt obligations Level 2 $ 5,155 $ — $ — $ 5,155 U.S. commercial paper Level 2 $ 11,412 $ — $ — $ 11,412 Total available-for-sale securities 26,656 1 — 26,657 Less amounts classified as cash equivalents (10,293 ) — — (10,293 ) Amounts classified as marketable securities $ 16,363 $ 1 $ — $ 16,364 There were no available-for-sale securities in an unrealized loss position as of March 31, 2020 and December 31, 2019. No significant facts or circumstances have arisen to indicate that there has been any deterioration in the creditworthiness of the issuers of these securities. As of March 31, 2020, we did not hold any investments with a maturity exceeding 12 months or that have been in a continuous loss position for 12 months or more. There were no realized gains or losses on the available-for-sale debt securities during the three months ended March 31, 2020 and 2019.

License Agreements

License Agreements	3 Months Ended
	Mar. 31, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
License Agreements	5. License Agreements Biogen Idec The first amended and restated collaboration agreement with Biogen Idec MA, Inc. (the “Biogen 1st ARCA”) amended and restated the collaboration agreement with Biogen (the “Biogen OCA”), to provide for the discovery, development and commercialization of small molecule BTK inhibitors. Under this agreement, the Company no longer has research obligations, but licenses granted to Biogen with respect to the research collaboration under the Biogen OCA (other than the licenses transferred to Takeda Oncology under the Takeda Agreement) remain in effect. In December 2018, the Company entered into a settlement agreement with Biogen whereas Biogen will no longer be obligated to pay future event-based payments or royalty payments to the Company. In December 2013, the Company entered into a second amended and restated collaboration agreement with Biogen, to provide the Company with an exclusive worldwide license to develop, manufacture and commercialize vecabrutinib Takeda In March 2011, Takeda Oncology purchased and exclusively licensed Biogen’s rights to a PDK1 inhibitor program and a pan-Raf inhibitor program which were both originally developed through a collaboration agreement between Sunesis and Biogen. In January 2014, the Company entered into an amended and restated license agreement with Takeda Oncology (the “Amended Takeda Agreement”), to provide the Company with an exclusive worldwide license to develop and commercialize preclinical inhibitors of PDK1. In December 2019, the Company partitioned the Amended Takeda Agreement into two separate agreements: (i) an amended and restated license agreement for PDK (the “PDK Agreement”), and (ii) an amended and restated license agreement for RAF (the “Millennium RAF Agreement”). Pursuant to the PDK Agreement, the Company may in the future be required to make up to $9.1 million in pre-commercialization milestone payments depending on its development of PDK1 inhibitors and tiered royalty payments depending on related product sales, if any, in the mid-single digits. DOT-1 In December 2019, Takeda Oncology assigned the Millennium RAF Agreement to DOT-1, a venture capital-funded biopharmaceutical company. The Company entered into a concurrent license agreement with DOT-1. Pursuant to this agreement, the Company received a $2.0 million upfront payment from DOT-1 to grant DOT-1 a worldwide, exclusive license of TAK-580. The agreement also includes up to $57.0 million in pre-commercialization, event-based milestone payments and royalty payments on future sales of TAK-580. The Company recognized the $2.0 million upfront payment as revenue in 2019 upon execution of the contract. All future event-based milestone and royalty payments are considered fully constrained and therefore, no revenue has been recognized during the three-months ended March 31, 2020. Denovo In December 2019, the Company entered into the Denovo License Agreement, pursuant to which Sunesis licensed vosaroxin intellectual property to Denovo, received an upfront payment of $0.2 million, and is eligible to receive up to $57.0 million in regulatory and commercial milestones payments and double-digit royalty payments on future sales of vosaroxin. The Company recognized as revenue the $0.1 million of the upfront payment in 2019 and the remaining $0.1 million during the three months ended March 31, 2020 when the identified performance obligation was satisfied. All future event-based milestone and royalty payments are considered fully constrained and therefore, no revenue has been recognized on these fully constrained variable consideration during the three-months ended March 31, 2020.

Notes Payable

Notes Payable	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
Notes Payable	6. Notes Payable In April 2019, the Company entered into a term loan agreement with Silicon Valley Bank (“SVB Loan Agreement”), pursuant to which the Company borrowed $5.5 million. In April 2020, the Company entered into a deferral agreement with Silicon Valley Bank (the “SVB Deferral Agreement”), which extended the interest-only payment period through June 30, 2021 and deferred the maturity date of the borrowings to June 1, 2023. Under the terms of the SVB Loan Agreement and SVB Deferral Agreement, the Company is required to make interest-only payments through June 30, 2021 on the borrowings at a floating rate equal to the greater of the Prime Rate as defined in the SVB Loan Agreement minus 2.25%, or 3.25%, followed by an amortization period of 24 months of equal monthly payments of principal plus interest amounts until paid in full. The Company’s obligations under the SVB Loan Agreement are secured by a first priority security interest in cash held at an account with SVB (the “Collateral Account”). The Company is obligated to maintain sufficient cash in the Collateral Account at all times in an amount equal to or greater than the outstanding balance of the borrowings. The Company has classified the Collateral Account as restricted cash on its condensed consolidated balance sheets as of March 31, 2020. The SVB Loan Agreement contains customary affirmative and negative covenants which, among other things, limit the Company’s ability to (i) incur additional indebtedness, (ii) pay dividends or make certain distributions, (iii) dispose of its assets, grant liens or encumber its assets or (iv) fundamentally alter the nature of its business. These covenants are subject to a number of exceptions and qualifications. The SVB Loan Agreement also contains customary events of default, including among other things, the Company’s failure to make any principal or interest payments when due, the occurrence of certain bankruptcy or insolvency events or its breach of the covenants under the SVB Loan Agreement. Upon the occurrence of an event of default, SVB may, among other things, accelerate the Company’s obligations under the SVB Loan Agreement . The Company was in compliance with all applicable covenants set forth in the SVB Loan Agreement as of March 31, 2020. The principal payments due under the SVB Loan Agreement have been classified as a current liability at March 31, 2020 due to the considerations discussed in Note 1 and the assessment that the material adverse change clause under the SVB Loan Agreement is not within the Company's control. The Company has not been notified of an event of default by the Lenders as of the date of the filing of this Form 10-Q. Aggregate future minimum payments due under the SVB Loan Agreement as of March 31, 2020 with terms of the SVB Deferral Agreement reflected, were as follows (in thousands): Through December 31, Total 2020 $ 135 2021 1,544 2022 2,843 2023 1,608 Total minimum payments 6,130 Less amount representing interest (630 ) Total notes payable as of March 31, 2020 5,500 Less unamortized debt discount and issuance costs (31 ) Less carrying amount of notes payable (5,469 ) Non-current portion of notes payable $ —

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2020
Equity [Abstract]
Stockholders' Equity	7. Stockholders’ Equity Controlled Equity Offerings Cantor Controlled Equity Offering During the three months ended March 31, 2020, no shares of common stock, respectively, were sold under the Controlled Equity Offering SM Aspire Common Stock Purchase Agreement During the three months ended March 31, 2020, no shares were issued under the Common Stock Purchase Agreement (the “CSPA”) with Aspire Capital Fund, LLC (“Aspire”). Aspire’s remaining purchase commitment was $10.9 million as of March 31, 2020 and Aspire’s obligation under the CSPA will automatically terminate on June 25, 2020.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	8. Stock-Based Compensation Employee and non-employee stock-based compensation expense is calculated based on the grant-date fair value of awards ultimately expected to vest, and recognized under the straight-line attribution method, assuming that all stock-based awards will vest. Forfeitures are recognized as they occur. The following table summarizes stock-based compensation expense related to the Company’s stock-based awards for the periods indicated (in thousands): Three months ended March 31, 2020 2019 Research and development $ 112 $ 156 General and administrative 193 216 Employee stock-based compensation expense 305 372 Non-employee stock-based compensation expense 14 45 Total stock-based compensation expense $ 319 $ 417

Leases

Leases	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Leases	9. Leases The Company’s operating lease obligation s solely ing The lease was entered into in January 2014 and was amended several times since 2014. The cash paid for operating lease liability was $0.2 million for the three months ended March 31, 2020. Maturity of lease liability is as follows (in thousands): Through December 31, 2020 $ 436 2021 294 Total rental payments 730 Less imputed interest (49 ) Present value of lease liability $ 681 The Company recognizes rent expense on a straight-line basis. The Company recorded rent expense of $0.1

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. The condensed consolidated financial statements include all adjustments (consisting only of normal recurring adjustments) that management believes are necessary for a fair presentation of the periods presented. The balance sheet as of December 31, 2019 was derived from the audited consolidated financial statements as of that date. These interim financial results are not necessarily indicative of results to be expected for the full year or any other period. These unaudited condensed consolidated financial statements and the notes accompanying them should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2019.
Adopted Accounting Pronouncements	Adopted Accounting Pronouncements In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement Recent Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments Financial Instruments—Credit Losses, Topic 326 Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842): Effective Dates Codification Improvements to Topic 326, Financial Instruments—Credit Losses, In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. .
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries, Sunesis Europe Limited, a United Kingdom corporation, and Sunesis Pharmaceuticals (Malta) Ltd., a Malta corporation. All intercompany balances and transactions have been eliminated in consolidation.
Significant Estimates and Judgments	Significant Estimates and Judgments The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the Company’s condensed consolidated financial statements and accompanying notes thereto. Actual results could differ materially from these estimates. Estimates, assumptions and judgments made by management include those related to valuation of marketable securities, equity and related instruments, revenue recognition, stock-based compensation and clinical trial accounting
Cash Equivalents, Restricted Cash, and Marketable Securities	Cash Equivalents, Restricted Cash, and Marketable Securities The Company considers all highly liquid securities with original maturities of three months or less from the date of purchase to be cash equivalents, which generally consist of money market funds, repurchase agreements, and corporate debt securities. Restricted cash consists of amounts pledged as collateral for term loan agreement as contractually required by the lender. Marketable securities consist of securities with original maturities of greater than three months, which may include U.S. and European government obligations and corporate debt securities.
Fair Value Measurements	Fair Value Measurements The Company measures cash equivalents at fair value on a recurring basis using the following hierarchy to prioritize valuation inputs, in accordance with applicable GAAP: Level 1 - Observable input such as quoted prices (unadjusted) in active markets for identical assets and liabilities that can be accessed at the measurement date; Level 2 - inputs other than quoted prices included within Level 1 that are observable, either directly or indirectly Level 3 - unobservable inputs The Company’s Level 2 valuations of marketable securities are generally derived from independent pricing services based upon quoted prices in active markets for similar securities, with prices adjusted for yield and number of days to maturity, or based on industry models using data inputs, such as interest rates and prices that can be directly observed or corroborated in active markets. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3, if any. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts of the Company’s financial instruments, including .

Loss per Common Share (Tables)

Loss per Common Share (Tables)	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Schedule of Potential Common Shares Issuable Pursuant to Outstanding Securities Excluded from Computation of Diluted Loss per Common Share	The following table represents the potential common shares issuable pursuant to outstanding securities as of the related period end dates that were excluded from the computation of diluted loss per common share because their inclusion would have had an anti-dilutive effect (in thousands): Three months ended March 31, 2020 2019 Warrants to purchase shares of common stock 208 218 Convertible preferred stock 19,714 16,331 Options to purchase shares of common stock 7,960 4,005 Outstanding securities not included in calculations 27,882 20,554

Financial Instruments (Tables)

Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value of Company's Financial Assets Measured on Recurring Basis	The following tables summarize the estimated fair value of the Company’s financial assets measured on a recurring basis as of the dates indicated, which are comprised solely of available-for-sale marketable securities with remaining contractual maturities of one year or less (in thousands): March 31, 2020 Input Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Money market funds Level 1 $ 19,050 $ — $ — $ 19,050 U.S. commercial paper Level 2 3,445 — — 3,445 Total available-for-sale securities 22,495 — — 22,495 Less amounts classified as cash equivalents (19,050 ) — — (19,050 ) Amounts classified as marketable securities $ 3,445 $ — $ — $ 3,445 December 31, 2019 Input Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Value Money market funds Level 1 $ 3,495 $ — $ — $ 3,495 U.S. Treasury securities Level 1 $ 1,594 $ 1 $ — $ 1,595 Repurchase agreements Level 2 $ 5,000 $ — $ — $ 5,000 U.S. corporate debt obligations Level 2 $ 5,155 $ — $ — $ 5,155 U.S. commercial paper Level 2 $ 11,412 $ — $ — $ 11,412 Total available-for-sale securities 26,656 1 — 26,657 Less amounts classified as cash equivalents (10,293 ) — — (10,293 ) Amounts classified as marketable securities $ 16,363 $ 1 $ — $ 16,364

Notes Payable (Tables)

Notes Payable (Tables)	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
Summary of Future Minimum Payments Under Loan Facility	Aggregate future minimum payments due under the SVB Loan Agreement as of March 31, 2020 with terms of the SVB Deferral Agreement reflected, were as follows (in thousands): Through December 31, Total 2020 $ 135 2021 1,544 2022 2,843 2023 1,608 Total minimum payments 6,130 Less amount representing interest (630 ) Total notes payable as of March 31, 2020 5,500 Less unamortized debt discount and issuance costs (31 ) Less carrying amount of notes payable (5,469 ) Non-current portion of notes payable $ —

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock-Based Compensation Expense Related to Company's Stock-Based Awards	The following table summarizes stock-based compensation expense related to the Company’s stock-based awards for the periods indicated (in thousands): Three months ended March 31, 2020 2019 Research and development $ 112 $ 156 General and administrative 193 216 Employee stock-based compensation expense 305 372 Non-employee stock-based compensation expense 14 45 Total stock-based compensation expense $ 319 $ 417

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Maturity of Lease Liability	Maturity of lease liability is as follows (in thousands): Through December 31, 2020 $ 436 2021 294 Total rental payments 730 Less imputed interest (49 ) Present value of lease liability $ 681

Company Overview - Additional I

Company Overview - Additional Information (Detail) - USD ($)	1 Months Ended
	Dec. 31, 2019		Mar. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Cash and cash equivalents, restricted cash, and marketable securities			$ 28,900,000
Accumulated deficit	$ 682,800,000	[1]	$ 688,575,000
License Agreement Terms [Member] | Takeda License Agreements [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Upfront payment received	2,000,000
License Agreement Terms [Member] | Takeda License Agreements [Member] | Maximum [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Potential pre-commercialization payments receivable	57,000,000
License Vosaroxin [Member] | Denovo Biopharma, LLC [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Upfront payment received	200,000
Potential regulatory and commercial payments receivable	$ 57,000,000
[1]	The condensed consolidated balance sheet as of December 31, 2019, has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019.

Loss per Common Share - Schedul

Loss per Common Share - Schedule of Potential Common Shares Issuable Pursuant to Outstanding Securities Excluded from Computation of Diluted Loss per Common Share (Detail) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding securities not included in calculations	27,882	20,554
Warrants to purchase shares of common stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding securities not included in calculations	208	218
Options to purchase shares of common stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding securities not included in calculations	7,960	4,005
Convertible preferred stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding securities not included in calculations	19,714	16,331

Financial Instruments - Fair Va

Financial Instruments - Fair Value of Company's Financial Assets Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, Amortized Cost	$ 22,495	$ 26,656
Available-for-sale securities, Gross Unrealized Gains		1
Available-for-sale securities, Estimated Fair Value	22,495	26,657
Less amounts classified as cash equivalents, Amortized Cost	(19,050)	(10,293)
Less amounts classified as cash equivalents, Estimated Fair Value	(19,050)	(10,293)
Amounts classified as marketable securities, Amortized Cost	3,445	16,363
Amounts classified as marketable securities, Gross Unrealized Gains		1
Amounts classified as marketable securities, Estimated Fair Value	3,445	16,364	[1]
Level 1 [Member] | Money market funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, Amortized Cost	19,050	3,495
Available-for-sale securities, Estimated Fair Value	19,050	3,495
Level 1 [Member] | U.S. Treasury securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, Amortized Cost		1,594
Available-for-sale securities, Gross Unrealized Gains		1
Available-for-sale securities, Estimated Fair Value		1,595
Level 2 [Member] | Repurchase agreements [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, Amortized Cost		5,000
Available-for-sale securities, Estimated Fair Value		5,000
Level 2 [Member] | U.S. commercial paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, Amortized Cost	3,445	11,412
Available-for-sale securities, Estimated Fair Value	$ 3,445	11,412
Level 2 [Member] | U.S. corporate debt obligations [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale securities, Amortized Cost		5,155
Available-for-sale securities, Estimated Fair Value		$ 5,155
[1]	The condensed consolidated balance sheet as of December 31, 2019, has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019.

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Unrealized gain or loss on available-for-sale securities	$ 0	$ 0
Realized gains or losses on available-for-sale securities	$ 0	$ 0

License Agreements - Additional

License Agreements - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended
	Dec. 31, 2019	Mar. 31, 2020	Sep. 30, 2017
Biogen [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Milestone payment			$ 2,500,000
Takeda License Agreements [Member] | License Agreement Terms [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Potential pre-commercialization milestone payments payable	$ 9,100,000
Upfront payment received	2,000,000
DOT-1 License Agreement [Member] | License Agreement Terms [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Potential pre-commercialization payments receivable	57,000,000
Received recognized on variable considerations		$ 0
Upfront payment received	2,000,000
Upfront payment recognized as revenue	2,000,000
Denovo License Agreement [Member] | License Vosaroxin [Member]
Research And Development Arrangement Contract To Perform For Others [Line Items]
Received recognized on variable considerations		0
Upfront payment received	200,000
Upfront payment recognized as revenue	100,000	$ 100,000
Regulatory, commercial milestones payments and double-digit royalty payments, receivable	$ 57,000,000

Notes Payable - Additional Info

Notes Payable - Additional Information (Detail) - Silicon Valley Bank [Member] - USD ($)	1 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Term Loan Agreement [Member]
Debt Instrument [Line Items]
Borrowing amount		$ 5,500,000
Debt instrument, payment terms		at a floating rate equal to the greater of the Prime Rate as defined in the SVB Loan Agreement minus 2.25%, or 3.25%, followed by an amortization period of 24 months of equal monthly payments of principal plus interest amounts until paid in full.
Debt instrument, frequency of periodic payment		monthly
Debt instrument, amortization period		24 months
Final payment fee, percentage		4.00%
Debt instrument, stated interest rate		3.25%
Term Loan Agreement [Member] | After 1st Anniversary but Prior to 2nd Anniversary of Effective Date [Member]
Debt Instrument [Line Items]
Prepayment fee		$ 110,000
Term Loan Agreement [Member] | After 2nd Anniversary of Effective Date [Member]
Debt Instrument [Line Items]
Prepayment fee		$ 55,000
Term Loan Agreement [Member] | Prime Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on floating rate		2.25%
Subsequent Event [Member] | SVB Deferral Agreement [Member]
Debt Instrument [Line Items]
Debt instrument, extended interest-only payments date	Jun. 30, 2021
Maturity date	Jun. 1, 2023
Debt instrument, amortization period	24 months

Notes Payable - Summary of Futu

Notes Payable - Summary of Future Minimum Payments Under Loan Facility (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	[1]
Debt Instrument [Line Items]
Total notes payable as of March 31, 2020	$ 5,500
Less carrying amount of notes payable	(5,469)	$ (5,465)
Notes payable [Member]
Debt Instrument [Line Items]
2020	135
2021	1,544
2022	2,843
2023	1,608
Total minimum payments	6,130
Less amount representing interest	(630)
Less unamortized debt discount and issuance costs	$ (31)
[1]	The condensed consolidated balance sheet as of December 31, 2019, has been derived from the audited financial statements as of that date included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019.

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)shares
Controlled Equity Offering Facilities [Member]
Stockholders Equity [Line Items]
Issuance of common stock, remaining offering value | $	$ 43.1
Controlled Equity Offering Facilities [Member] | Common Stock [Member]
Stockholders Equity [Line Items]
Common stock, shares sold | shares	0
CSPA [Member] | Aspire [Member] | Registration Rights Agreement [Member]
Stockholders Equity [Line Items]
Common stock, shares sold | shares	0
Remaining purchase commitment | $	$ 10.9
Date of termination	Jun. 25, 2020

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock-Based Compensation Expense Related to Company's Stock-Based Awards (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation, Allocation and Classification in Financial Statements
Total stock-based compensation expense	$ 319	$ 417
Employee stock-based compensation expense [Member]
Share-based Compensation, Allocation and Classification in Financial Statements
Total stock-based compensation expense	305	372
Non-employee stock-based compensation expense [Member]
Share-based Compensation, Allocation and Classification in Financial Statements
Total stock-based compensation expense	14	45
Research and development [Member]
Share-based Compensation, Allocation and Classification in Financial Statements
Total stock-based compensation expense	112	156
General and administrative [Member]
Share-based Compensation, Allocation and Classification in Financial Statements
Total stock-based compensation expense	$ 193	$ 216

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Leases [Line Items]
Cash paid for operating lease liability	$ 0.2
Rent expense	$ 0.1	$ 0.1
Original Operating Lease [Member]
Leases [Line Items]
Operating lease agreement, original date	2014-01
Fifth Amended Operating Lease [Member]
Leases [Line Items]
Lease expiration date	Jun. 30, 2021
Operating lease agreement, date of amendment	2017-12
Operating lease, property description	The lease was last amended in December 2017 to extend the expiration date to June 30, 2021, with an option to extend the lease for two additional years. The Company did not assume the option to extend the lease term for two additional years in its determination of the lease term as the exercise of the option was not reasonably certain when the lease was last amended in December 2017.
Lessee, operating lease, existence of option to extend [true false]	true
Option to extend the lease	option to extend the lease for two additional years.
Operating lease, renewal term	2 years
Operating lease, remaining term	1 year 3 months

Leases - Schedule of Maturity o

Leases - Schedule of Maturity of Lease Liability (Detail) $ in Thousands	Mar. 31, 2020USD ($)
Leases [Abstract]
2020	$ 436
2021	294
Total rental payments	730
Less imputed interest	(49)
Present value of lease liability	$ 681