Fresh Tracks Therapeutics (FRTX) 10-Q 12 Jul 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	6 Months Ended
	Jun. 30, 2019shares
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Trading Symbol	VICL
Entity Registrant Name	VICAL INC
Entity Central Index Key	0000819050
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity File Number	000-21088
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Address, State or Province	California
Entity Common Stock, Shares Outstanding	22,841,278

Balance Sheets (Unaudited)

Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 10,813	$ 11,870
Marketable securities, available-for-sale	30,907	36,201
Receivables and other assets	979	1,128
Total current assets	42,699	49,199
Long-term investments	0	2,386
Property and equipment, net	2	100
Other assets	0	659
Total assets	42,701	52,344
Current liabilities:
Accounts payable and accrued expenses	1,159	3,551
Deferred revenue	0	30
Total current liabilities	1,159	3,581
Stockholders' equity:
Preferred stock, $0.01 par value, 5,000 shares authorized, none issued and outstanding	0	0
Common stock, $0.01 par value, 50,000 shares authorized, 22,841 and 21,817 shares issued and outstanding at June 30, 2019 and December 31, 2018, respectively	229	218
Additional paid-in capital	490,343	490,337
Accumulated deficit	(449,072)	(442,064)
Accumulated other comprehensive income	42	272
Total stockholders' equity	41,542	48,763
Total liabilities and stockholders' equity	$ 42,701	$ 52,344

Balance Sheets (Unaudited) (Par

Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Jun. 30, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	22,841,000	21,817,000
Common stock, shares outstanding	22,841,000	21,817,000

Statements of Operations (Unaud

Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues:
Contract revenue	$ 0	$ 725	$ 0	$ 1,431
License and royalty revenue	0	10	0	20
Total revenues	0	735	0	1,451
Operating expenses:
Research and development	759	3,602	4,641	7,266
Manufacturing and production	0	0	0	1,436
General and administrative	2,242	2,261	3,618	4,378
Total operating expenses	3,001	5,863	8,259	13,080
Loss from operations	(3,001)	(5,128)	(8,259)	(11,629)
Other income:
Investment and other income, net	571	260	1,251	491
Net loss	$ (2,430)	$ (4,868)	$ (7,008)	$ (11,138)
Basic and diluted net loss per share	$ (0.11)	$ (0.22)	$ (0.31)	$ (0.51)
Weighted average shares used in computing basic and diluted net loss per share	22,825	21,837	22,404	21,834

Statements of Comprehensive Los

Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (2,430)	$ (4,868)	$ (7,008)	$ (11,138)
Unrealized gain (loss) on available-for-sale and long-term marketable securities:
Unrealized gain arising during holding period, net of tax benefit of $0 and $6 for three months ended June 30, 2019 and 2018, respectively, and $0 and $6 for six months ended June 30, 2019 and 2018, respectively	25	73	143	8
Less: Reclassification adjustment for gains included in net loss	0	0	(373)	0
Other comprehensive gain (loss)	25	73	(230)	8
Total comprehensive loss	$ (2,405)	$ (4,795)	$ (7,238)	$ (11,130)

Statements of Comprehensive L_2

Statements of Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Unrealized gain arising during holding period, tax benefit	$ 0	$ 6	$ 0	$ 6

Statements of Stockholders' Equ

Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income/(Loss) [Member]
Beginning Balance at Dec. 31, 2017	$ 63,577	$ 218	$ 489,975	$ (426,738)	$ 122
Beginning Balance, shares at Dec. 31, 2017		21,802
Net loss	(6,270)			(6,270)
Retained earnings adjustment upon adoption of ASU 2014-09	928			928
Other comprehensive gain (loss)	(65)				(65)
Issuance of common stock underlying restricted stock units net of shares withheld to settle withholding taxes	1		1
Issuance of common stock underlying restricted stock units net of shares withheld to settle withholding taxes, shares		13
Non-cash compensation expense related to grant of equity based compensation	47		47
Ending Balance at Mar. 31, 2018	58,218	$ 218	490,023	(432,080)	57
Ending Balance, shares at Mar. 31, 2018		21,815
Beginning Balance at Dec. 31, 2017	63,577	$ 218	489,975	(426,738)	122
Beginning Balance, shares at Dec. 31, 2017		21,802
Net loss	(11,138)
Other comprehensive gain (loss)	8
Ending Balance at Jun. 30, 2018	53,585	$ 218	490,185	(436,948)	130
Ending Balance, shares at Jun. 30, 2018		21,815
Beginning Balance at Mar. 31, 2018	58,218	$ 218	490,023	(432,080)	57
Beginning Balance, shares at Mar. 31, 2018		21,815
Net loss	(4,868)			(4,868)
Other comprehensive gain (loss)	73				73
Non-cash compensation expense related to grant of equity based compensation	162		162
Ending Balance at Jun. 30, 2018	53,585	$ 218	490,185	(436,948)	130
Ending Balance, shares at Jun. 30, 2018		21,815
Beginning Balance at Dec. 31, 2018	$ 48,763	$ 218	490,337	(442,064)	272
Beginning Balance, shares at Dec. 31, 2018	21,817	21,817
Net loss	$ (4,578)			(4,578)
Other comprehensive gain (loss)	(255)				(255)
Issuance of common stock upon exercise of warrants	10	$ 10
Issuance of common stock upon exercise of warrants, shares		993
Issuance of common stock underlying restricted stock units net of shares withheld to settle withholding taxes	1	$ 1
Issuance of common stock underlying restricted stock units net of shares withheld to settle withholding taxes, shares		13
Non-cash compensation expense related to grant of equity based compensation	(19)		(19)
Ending Balance at Mar. 31, 2019	43,922	$ 229	490,318	(446,642)	17
Ending Balance, shares at Mar. 31, 2019		22,823
Beginning Balance at Dec. 31, 2018	$ 48,763	$ 218	490,337	(442,064)	272
Beginning Balance, shares at Dec. 31, 2018	21,817	21,817
Net loss	$ (7,008)
Other comprehensive gain (loss)	(230)
Ending Balance at Jun. 30, 2019	$ 41,542	$ 229	490,343	(449,072)	42
Ending Balance, shares at Jun. 30, 2019	22,841	22,841
Beginning Balance at Mar. 31, 2019	$ 43,922	$ 229	490,318	(446,642)	17
Beginning Balance, shares at Mar. 31, 2019		22,823
Net loss	(2,430)			(2,430)
Other comprehensive gain (loss)	25				25
Issuance of common stock underlying restricted stock units net of shares withheld to settle withholding taxes	2		2
Issuance of common stock underlying restricted stock units net of shares withheld to settle withholding taxes, shares		18
Non-cash compensation expense related to grant of equity based compensation	23		23
Ending Balance at Jun. 30, 2019	$ 41,542	$ 229	$ 490,343	$ (449,072)	$ 42
Ending Balance, shares at Jun. 30, 2019	22,841	22,841

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net loss	$ (7,008)	$ (11,138)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	18	119
Accretion of discount on short-term investments	(227)	(70)
Write-off of abandoned patents	0	673
Gain on sale of property and equipment	(309)	0
Net gain on sale of long-term investment	(373)	0
Compensation related to stock options and awards	4	209
Changes in operating assets and liabilities:
Receivables and other assets	808	3,882
Accounts payable and accrued expenses	(2,487)	(2,058)
Employee termination benefits accrual	96	2
Deferred revenue	(30)	(249)
Net cash used in operating activities	(9,508)	(8,630)
Cash flows from investing activities:
Proceeds from the sale of long-term investment	2,469	0
Maturities of marketable securities	12,000	14,719
Purchases of marketable securities	(6,419)	(20,843)
Sale of property and equipment	388	0
Purchases of property and equipment	0	(16)
Net cash provided by (used in) investing activities	8,438	(6,140)
Cash flows from financing activities:
Net proceeds from issuance of common stock	13	1
Payment of withholding taxes for net settlement of restricted stock units	0	(1)
Net cash provided by financing activities	13	0
Net decrease in cash, cash equivalents and restricted cash	(1,057)	(14,770)
Cash, cash equivalents and restricted cash at beginning of period	11,870	25,033
Cash, cash equivalents and restricted cash at end of period	$ 10,813	$ 10,263

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	1. BASIS OF PRESENTATION Vical Incorporated, or the Company, a Delaware corporation, was incorporated in April 1987 and has devoted substantially all of its resources since that time to the research and development of biopharmaceutical products, including those based on its patented DNA delivery technologies for the prevention and treatment of serious or life-threatening diseases. The unaudited financial statements at June 30, 2019, and for the three and six months ended June 30, 2019 and 2018, have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission, or SEC, and with accounting principles generally accepted in the United States applicable to interim financial statements. These unaudited financial statements have been prepared on the same basis as the audited financial statements included in the Company’s Annual Report on Form 10-K and include all adjustments, consisting of only normal recurring accruals, which in the opinion of management are necessary to present fairly the Company’s financial position as of the interim date and results of operations for the interim periods presented. Interim results are not necessarily indicative of results expected for a full year or future periods. The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from those estimates. These unaudited financial statements should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2018, included in its Annual Report on Form 10-K filed with the SEC. Cash, Cash Equivalents and Marketable Securities Cash and cash equivalents consist of cash and highly liquid securities with original maturities at the date of acquisition of ninety days or less and that can be liquidated without prior notice or penalty. Investments with an original maturity of more than ninety days are considered marketable securities and have been classified by management as available-for-sale. These investments are classified as current assets, even though the stated maturity date may be one year or more beyond the current balance sheet date which reflects management’s intention to use the proceeds from sales of these securities to fund its operations, as necessary. Such investments are carried at fair value, with unrealized gains and losses included as a separate component of stockholders’ equity. Realized gains and losses from the sale of available-for-sale securities or the amounts, net of tax, reclassified out of accumulated other comprehensive income (loss), if any, are determined on a specific identification basis. Revenue Recognition The Company recognizes revenue when control of its products and services is transferred to its customers in an amount that reflects the consideration the Company expects to receive from its customers in exchange for those products and services. This process involves identifying the contract with a customer, determining the performance obligations in the contract, determining the contract price, allocating the contract price to the distinct performance obligations in the contract, and recognizing revenue when the performance obligations have been satisfied. 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 a performance obligation satisfied once it 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 it determines there are no uncertainties regarding payment terms or transfer of control. Research and Development Costs Research and development costs are expensed as incurred. Research and development costs include salaries and personnel-related costs, supplies and materials, outside services, costs of conducting preclinical and clinical trials, facilities costs and amortization of intangible assets. The Company accounts for its clinical trial costs by estimating the total cost to treat a patient in each clinical trial, and accruing this total cost for the patient over the estimated treatment period, which corresponds with the period over which the services are performed, beginning when the patient enrolls in the clinical trial. This estimated cost includes payments to the site conducting the trial, and patient-related lab and other costs related to the conduct of the trial. Cost per patient varies based on the type of clinical trial, the site of the clinical trial, the method of administration of the treatment, and the number of treatments that a patient receives. Treatment periods vary depending on the clinical trial. The Company makes revisions to the clinical trial cost estimates in the current period, as clinical trials progress. Manufacturing and Production Costs Manufacturing and production costs include expenses related to manufacturing contracts and expenses for the production of plasmid DNA for use in the Company’s research and development efforts. Production expenses related to the Company’s research and development efforts are expensed as incurred. Net Loss Per Share Basic and diluted net loss per share has been computed using the weighted-average number of shares of common stock outstanding during the period. The weighted average number of shares used to compute diluted loss per share excludes any assumed exercise of stock options and warrants and any assumed issuance of common stock under restricted stock units (RSUs) as the effect would be antidilutive. Common stock equivalents of 6.2 million and 7.2 million for the three months ended June 30, 2019 and 2018, respectively, were excluded from the calculation because of their antidilutive effect. Common stock equivalents of 6.6 million and 7.2 million for the six months ended June 30, 2019 and 2018, respectively, were excluded from the calculation because of their antidilutive effect. Stock-Based Compensation The Company records its compensation expense associated with stock options and other forms of equity compensation based on their fair value at the date of grant using the Black-Scholes-Merton option pricing model. Stock-based compensation includes amortization related to stock option awards based on the estimated grant date fair value. Stock-based compensation expense related to stock options is recognized ratably over the vesting period of the option. In addition, the Company records expense related to RSUs granted based on the fair value of those awards on the grant date. The fair value related to the RSUs is amortized to expense over the vesting term of those awards. Forfeitures of stock options and RSUs are recognized as they occur. Stock-based compensation expense for a stock-based award with a performance condition is recognized when the achievement of such performance condition is determined to be probable. If the outcome of such performance condition is not determined to be probable or is not met, no compensation expense is recognized and any previously recognized compensation expense is reversed. Recent Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842).” The new standard requires a lessee to record on the balance sheet the assets and liabilities for the rights and obligations created by leases with lease terms of more than 12 months and requires both lessees and lessors to disclose certain key information about lease transactions. The standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company adopted this standard during the first quarter of 2019. The adoption of this guidance did not have a material impact on the Company’s financial statements and related disclosures.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	2. STOCK-BASED COMPENSATION Total stock-based compensation expense was allocated to research and development, manufacturing and production and general and administrative expense as follows (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Research and development $ 6 $ 48 $ (44 ) $ 76 Manufacturing and production — — — (68 ) General and administrative 17 114 48 201 Total stock-based compensation expense $ 23 $ 162 $ 4 $ 209 There were no stock-based awards granted by the Company during the three and six months ended June 30, 2019. During the six months ended June 30, 2018, the Company granted stock-based awards with a total estimated value of $0.4 million, which were equal to 2.5% of the outstanding shares of common stock at the end of the period. At June 30, 2019, total unrecognized estimated compensation expense related to unvested stock-based awards granted prior to that date was $0.1 million, which is expected to be recognized over a weighted-average period of 1.3 years.

Marketable Securities, Availabl

Marketable Securities, Available for Sale	6 Months Ended
	Jun. 30, 2019
Investments Debt And Equity Securities [Abstract]
Marketable Securities, Available for Sale	3. MARKETABLE SECURITIES, AVAILABLE FOR SALE The following is a summary of available-for-sale marketable securities (in thousands): June 30, 2019 Amortized Cost Unrealized Gain Unrealized Loss Market Value U.S. treasuries $ 30,865 $ 42 $ — $ 30,907 $ 30,865 $ 42 $ — $ 30,907 December 31, 2018 Amortized Cost Unrealized Gain Unrealized Loss Market Value U.S. treasuries $ 36,219 $ — $ 18 $ 36,201 $ 36,219 $ — $ 18 $ 36,201 At June 30, 2019, none of these securities were scheduled to mature outside of one year. The Company did not realize any gains or losses on sales of available-for-sale securities for the three and six months ended June 30, 2019. As of June 30, 2019, none of the securities had been in a continuous material unrealized loss position longer than one year.

Other Balance Sheet Accounts

Other Balance Sheet Accounts	6 Months Ended
	Jun. 30, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Other Balance Sheet Accounts	4. OTHER BALANCE SHEET ACCOUNTS Accounts payable and accrued expenses consisted of the following (in thousands): June 30, December 31, 2019 2018 Employee compensation $ 335 $ 1,768 Post-termination benefit accrual 96 — Clinical trial accruals 111 1,000 Accounts payable 544 412 Other accrued liabilities 73 371 Total accounts payable and accrued expenses $ 1,159 $ 3,551

Long-Term Investments

Long-Term Investments	6 Months Ended
	Jun. 30, 2019
Investments All Other Investments [Abstract]
Long-Term Investments	5. LONG-TERM INVESTMENTS During the six months ended June 30, 2019, the Company sold its auction rate security classified as a long-term investment with a par value of $2.5 million. Included in investment and other income for the six months ended June 30, 2019 is a net gain of $0.4 million related to the sale.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	6. FAIR VALUE MEASUREMENTS The Company measures fair value 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 at the measurement date. 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. Fair value measurements are based on 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; and • Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. Cash equivalents, marketable securities and long-term investments measured at fair value are classified in the table below in one of the three categories described above (in thousands): Fair Value Measurements June 30, 2019 Level 1 Level 2 Level 3 Total Money market funds $ 10,178 $ — $ — $ 10,178 U.S. treasuries 30,907 — — 30,907 $ 41,085 $ — $ — $ 41,085 Fair Value Measurements December 31, 2018 Level 1 Level 2 Level 3 Total Money market funds $ 11,523 $ — $ — $ 11,523 U.S. treasuries 36,201 — — 36,201 Auction rate securities — — 2,386 2,386 $ 47,724 $ — $ 2,386 $ 50,110 The Company invests in U.S. treasury securities, certificates of deposit and money market funds, which are valued based on publicly available quoted market prices for identical securities as of June 30, 2019. The Company determines the fair value of corporate bonds and other government-sponsored enterprise related securities with the aid of valuations provided by third parties using proprietary valuation models and analytical tools. These valuation models and analytical tools use market pricing or similar instruments that are both objective and publicly available, including matrix pricing or reported trades, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids and/or offers. The Company validates the valuations received from its primary pricing vendors for its Level 2 securities by examining the inputs used in that vendor’s pricing process and determines whether they are reasonable and observable. The Company also compares those valuations to recent reported trades for those securities. As of June 30, 2019 and December 31, 2018, the Company had no investments in Level 2 securities. The Company did not transfer any investments between level categories during the six months ended June 30, 2019. Activity for assets measured at fair value using significant unobservable inputs (Level 3) is presented in the table below (in thousands): Balance at December 31, 2018 $ 2,386 Change in fair market value included in other comprehensive loss 83 Sale of Level 3 security (2,469 ) Balance at June 30, 2019 $ — Total gains or losses for the period included in net loss attributable to the change in unrealized gains or losses relating to assets still held at the reporting date $ —

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. COMMITMENTS AND CONTINGENCIES In the ordinary course of business, the Company may become a party to additional lawsuits involving various matters. The Company is unaware of any such lawsuits presently pending against it which, individually or in the aggregate, are deemed to be material to the Company’s financial condition or results of operations. The Company prosecutes its intellectual property vigorously to obtain the broadest valid scope for its patents. Due to uncertainty of the ultimate outcome of these matters, the impact on future operating results or the Company’s financial condition is not subject to reasonable estimates.

Astellas Out-License Agreements

Astellas Out-License Agreements	6 Months Ended
	Jun. 30, 2019
Astellas Out-License Agreements [Member]
Astellas License Agreements	8. ASTELLAS OUT-LICENSE AGREEMENTS In July 2011, the Company entered into license agreements with Astellas Pharma Inc., or Astellas, related to the Company’s CMV program. The license agreement was terminated in February 2018. Under the terms of the agreements, the Company was performing research and development services and manufacturing services which were being paid for by Astellas. During the three and six months ended June 30, 2018, the Company recognized $0.7 million and $1.2 million, respectively, of revenue related to these contract services.

Facility Lease

Facility Lease	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Facility Lease	9. FACILITY LEASE The Company occupies approximately 17,000 square feet of research laboratory and office space at a single site in San Diego, California under a sublease with Genopis, Inc., or Genopis. In July 2018, the Company entered into an agreement with Genopis to sell the Company’s idle manufacturing assets for $1.7 million. As part of the agreement, Genopis agreed to sublease 51,400 square feet of the Company’s facility through the remaining term of the Company’s lease, which expired on December 31, 2018. Genopis was also required to sign a long-term lease with the facility’s landlord beginning on January 1, 2019. Genopis agreed to sublease 17,000 square feet of the facility (consisting of lab and office space) to the Company at no cost for the one-year period ending on December 31, 2019. The fair value of rent of the lab and office space that the Company is occupying at no cost was $0.4 million as of June 30, 2019 and is recorded in receivables and other assets.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Stockholders' Equity	1 0 . STOCKHOLDERS’ EQUITY As of the date of this filing, the Company has on file a shelf registration statement that allows it to raise up to an additional $40.0 million from the sale of common stock, preferred stock, debt securities and/or warrants, subject to limitations on the amount of securities that it may sell under the registration statement in any 12-month period. Specific terms of any offering under a shelf registration statement and the securities involved would be established at the time of sale. In November 2017, the Company sold 9,194,286 shares of its common stock in a public offering at a price of $1.75 per share, including an overallotment of 2,142,857 shares issued at a price of $1.75 per share, and pre-funded warrants to purchase 7,234,285 shares of common stock at a purchase price of $1.74 per share. The pre-funded warrants have an exercise price of $0.01 per share and may be exercised at any time. In March 2019, 993,211 warrants were exercised. As of June 30, 2019, warrants to purchase 6,241,074 shares of common stock were outstanding.

Related Party Transaction

Related Party Transaction	6 Months Ended
	Jun. 30, 2019
Related Party Transactions [Abstract]
Related Party Transaction	1 1 . RELATED PARTY TRANSACTION On April 4, 2017, the Company entered into a research collaboration agreement with AnGes. As of the date of the transaction, AnGes held 18.6% of the outstanding stock of the Company. Pursuant to the collaboration agreement, AnGes agreed to make a non-refundable payment to the Company of $750,000 and the Company agreed to conduct certain research activities related to a development program targeting chronic hepatitis B. An amendment to the agreement was executed in September 2018 that added an additional non-refundable payment from AnGes to the Company of $145,000. The HBV program was cancelled in 2019. As of June 30, 2019, the Company had recognized the full $895,000 as contract revenue.

Restructuring Costs

Restructuring Costs	6 Months Ended
	Jun. 30, 2019
Restructuring And Related Activities [Abstract]
Restructuring Costs	12. RESTRUCTURING COSTS In February 2019, the Company made the decision to discontinue the Phase 2 clinical trial of VL-2397. As a result, the Company restructured its operations to conserve capital and recorded restructuring charges of $0.6 million and $2.1 million during the three and six months ended June 30, 2019, respectively. In January 2018, the Company and Astellas announced that ASP0113 did not meet its primary endpoint in a Phase 3 clinical study in CMV end organ disease, after which Astellas informed the Company that it was terminating further development. As a result, the Company restructured its operations to conserve capital, which included a staff reduction of 40 employees and the write-off of certain intangible assets. The Company recorded charges for one-time employee termination benefits of $1.1 million and for intangible asset impairments of $0.3 million during the six months ended June 30, 2018. Overhead costs associated with the former manufacturing facility of $0.6 million and $1.0 million were recognized as general and administrative expense during the three and six months ended June 30, 2018, respectively. The following table summarizes the restructuring charges (in thousands) recorded for the six months ended June 30, 2019 and 2018: Employee Termination Asset 2019 Benefits Impairments Total Research and development $ 2,018 $ — $ 2,018 General and administrative 70 — 70 $ 2,088 $ — $ 2,088 Employee Termination Asset 2018 Benefits Impairments Total Research and development $ 272 $ 267 $ 539 Manufacturing and production 735 — 735 General and administrative 117 — 117 $ 1,124 $ 267 $ 1,391 The following table sets forth the accrual activity for employee termination benefits for the six months ended June 30, 2019 (in thousands). Balance at December 31, 2018 $ — Accruals 2,088 Payments (1,992 ) Balance at June 30, 2019 $ 96

Merger Agreement

Merger Agreement	6 Months Ended
	Jun. 30, 2019
Business Combinations [Abstract]
Merger Agreement	1 3 . MERGER AGREEMENT On June 2, 2019, the Company entered into an Agreement and Plan of Merger and Reorganization, or the Merger Agreement, with Brickell Biotech, Inc., a Delaware corporation and clinical-stage medical dermatology company, or Brickell Biotech, and Victory Subsidiary, Inc., a Delaware corporation and wholly owned subsidiary of the Company, or Merger Sub. Upon the terms and subject to satisfaction of the conditions described in the Merger Agreement, including approval of the transaction by the Company’s stockholders, Merger Sub will be merged with and into Brickell Biotech, or the Merger, with Brickell Biotech surviving the Merger as a wholly owned subsidiary of the Company. Concurrent with the execution of the Merger Agreement, Brickell entered into a Funding Agreement, or the Funding Agreement, with NovaQuest Co-Investment Fund X, L.P., or NovaQuest, pursuant to which NovaQuest committed to provide up to $25.0 million in near-term research and development funding to Brickell following the closing of the Merger, or the Concurrent Financing, with $5.6 million of the commitment expected to be paid promptly following the closing of the Merger and the remaining portion of the commitment expected to be paid in quarterly payments equal to 67% of invoiced research and development expenses incurred during the subsequent four fiscal quarters. In connection with the Concurrent Financing, immediately following the closing of the Merger, the combined company will issue warrants to NovaQuest, or the NovaQuest Warrants, to purchase shares of Vical common stock. The number of shares of Vical common stock underlying the NovaQuest Warrants will be based on 10% warrant coverage on the $25.0 million NovaQuest funding commitment and the final exchange ratio for the Merger, or the Exchange Ratio, and the exercise price of the NovaQuest Warrants will be determined based on a 10% premium to the Brickell price per share of common stock implied value in the Merger, as adjusted for the Exchange Ratio. Immediately following the Merger, the former Brickell securityholders and NovaQuest, collectively, are expected to own, subject to adjustment, approximately 60% of the aggregate number of shares of Vical common stock, and the securityholders of Vical immediately prior to the Merger are expected to own, subject to adjustment, approximately 40% of the aggregate number of shares of Vical common stock (in each case on a fully diluted basis using the treasury stock method in instances other than with respect to the NovaQuest Warrants and certain equity issuances by Brickell following the signing of the Merger Agreement and prior to the completion of the Merger).

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Cash, Cash Equivalents and Marketable Securities	Cash, Cash Equivalents and Marketable Securities Cash and cash equivalents consist of cash and highly liquid securities with original maturities at the date of acquisition of ninety days or less and that can be liquidated without prior notice or penalty. Investments with an original maturity of more than ninety days are considered marketable securities and have been classified by management as available-for-sale. These investments are classified as current assets, even though the stated maturity date may be one year or more beyond the current balance sheet date which reflects management’s intention to use the proceeds from sales of these securities to fund its operations, as necessary. Such investments are carried at fair value, with unrealized gains and losses included as a separate component of stockholders’ equity. Realized gains and losses from the sale of available-for-sale securities or the amounts, net of tax, reclassified out of accumulated other comprehensive income (loss), if any, are determined on a specific identification basis.
Revenue Recognition	Revenue Recognition The Company recognizes revenue when control of its products and services is transferred to its customers in an amount that reflects the consideration the Company expects to receive from its customers in exchange for those products and services. This process involves identifying the contract with a customer, determining the performance obligations in the contract, determining the contract price, allocating the contract price to the distinct performance obligations in the contract, and recognizing revenue when the performance obligations have been satisfied. 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 a performance obligation satisfied once it 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 it determines there are no uncertainties regarding payment terms or transfer of control.
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred. Research and development costs include salaries and personnel-related costs, supplies and materials, outside services, costs of conducting preclinical and clinical trials, facilities costs and amortization of intangible assets. The Company accounts for its clinical trial costs by estimating the total cost to treat a patient in each clinical trial, and accruing this total cost for the patient over the estimated treatment period, which corresponds with the period over which the services are performed, beginning when the patient enrolls in the clinical trial. This estimated cost includes payments to the site conducting the trial, and patient-related lab and other costs related to the conduct of the trial. Cost per patient varies based on the type of clinical trial, the site of the clinical trial, the method of administration of the treatment, and the number of treatments that a patient receives. Treatment periods vary depending on the clinical trial. The Company makes revisions to the clinical trial cost estimates in the current period, as clinical trials progress.
Manufacturing and Production Costs	Manufacturing and Production Costs Manufacturing and production costs include expenses related to manufacturing contracts and expenses for the production of plasmid DNA for use in the Company’s research and development efforts. Production expenses related to the Company’s research and development efforts are expensed as incurred.
Net Loss Per Share	Net Loss Per Share Basic and diluted net loss per share has been computed using the weighted-average number of shares of common stock outstanding during the period. The weighted average number of shares used to compute diluted loss per share excludes any assumed exercise of stock options and warrants and any assumed issuance of common stock under restricted stock units (RSUs) as the effect would be antidilutive. Common stock equivalents of 6.2 million and 7.2 million for the three months ended June 30, 2019 and 2018, respectively, were excluded from the calculation because of their antidilutive effect. Common stock equivalents of 6.6 million and 7.2 million for the six months ended June 30, 2019 and 2018, respectively, were excluded from the calculation because of their antidilutive effect.
Stock-Based Compensation	Stock-Based Compensation The Company records its compensation expense associated with stock options and other forms of equity compensation based on their fair value at the date of grant using the Black-Scholes-Merton option pricing model. Stock-based compensation includes amortization related to stock option awards based on the estimated grant date fair value. Stock-based compensation expense related to stock options is recognized ratably over the vesting period of the option. In addition, the Company records expense related to RSUs granted based on the fair value of those awards on the grant date. The fair value related to the RSUs is amortized to expense over the vesting term of those awards. Forfeitures of stock options and RSUs are recognized as they occur. Stock-based compensation expense for a stock-based award with a performance condition is recognized when the achievement of such performance condition is determined to be probable. If the outcome of such performance condition is not determined to be probable or is not met, no compensation expense is recognized and any previously recognized compensation expense is reversed.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842).” The new standard requires a lessee to record on the balance sheet the assets and liabilities for the rights and obligations created by leases with lease terms of more than 12 months and requires both lessees and lessors to disclose certain key information about lease transactions. The standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company adopted this standard during the first quarter of 2019. The adoption of this guidance did not have a material impact on the Company’s financial statements and related disclosures.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Total Stock-Based Compensation Expense	Total stock-based compensation expense was allocated to research and development, manufacturing and production and general and administrative expense as follows (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Research and development $ 6 $ 48 $ (44 ) $ 76 Manufacturing and production — — — (68 ) General and administrative 17 114 48 201 Total stock-based compensation expense $ 23 $ 162 $ 4 $ 209

Marketable Securities, Availa_2

Marketable Securities, Available for Sale (Tables)	6 Months Ended
	Jun. 30, 2019
Investments Debt And Equity Securities [Abstract]
Summary of Available-for-Sale Marketable Securities	The following is a summary of available-for-sale marketable securities (in thousands): June 30, 2019 Amortized Cost Unrealized Gain Unrealized Loss Market Value U.S. treasuries $ 30,865 $ 42 $ — $ 30,907 $ 30,865 $ 42 $ — $ 30,907 December 31, 2018 Amortized Cost Unrealized Gain Unrealized Loss Market Value U.S. treasuries $ 36,219 $ — $ 18 $ 36,201 $ 36,219 $ — $ 18 $ 36,201

Other Balance Sheet Accounts (T

Other Balance Sheet Accounts (Tables)	6 Months Ended
	Jun. 30, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Accounts Payable and Accrued Expenses	Accounts payable and accrued expenses consisted of the following (in thousands): June 30, December 31, 2019 2018 Employee compensation $ 335 $ 1,768 Post-termination benefit accrual 96 — Clinical trial accruals 111 1,000 Accounts payable 544 412 Other accrued liabilities 73 371 Total accounts payable and accrued expenses $ 1,159 $ 3,551

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Summary of Cash Equivalents, Marketable Securities and Long-Term Investments Measured at Fair Value	Cash equivalents, marketable securities and long-term investments measured at fair value are classified in the table below in one of the three categories described above (in thousands): Fair Value Measurements June 30, 2019 Level 1 Level 2 Level 3 Total Money market funds $ 10,178 $ — $ — $ 10,178 U.S. treasuries 30,907 — — 30,907 $ 41,085 $ — $ — $ 41,085 Fair Value Measurements December 31, 2018 Level 1 Level 2 Level 3 Total Money market funds $ 11,523 $ — $ — $ 11,523 U.S. treasuries 36,201 — — 36,201 Auction rate securities — — 2,386 2,386 $ 47,724 $ — $ 2,386 $ 50,110
Summary of Activity for Assets Measured at Fair Value Using Significant Unobservable Inputs	Activity for assets measured at fair value using significant unobservable inputs (Level 3) is presented in the table below (in thousands): Balance at December 31, 2018 $ 2,386 Change in fair market value included in other comprehensive loss 83 Sale of Level 3 security (2,469 ) Balance at June 30, 2019 $ — Total gains or losses for the period included in net loss attributable to the change in unrealized gains or losses relating to assets still held at the reporting date $ —

Restructuring Costs (Tables)

Restructuring Costs (Tables)	6 Months Ended
	Jun. 30, 2019
Restructuring And Related Activities [Abstract]
Summary of Restructuring Charges	The following table summarizes the restructuring charges (in thousands) recorded for the six months ended June 30, 2019 and 2018: Employee Termination Asset 2019 Benefits Impairments Total Research and development $ 2,018 $ — $ 2,018 General and administrative 70 — 70 $ 2,088 $ — $ 2,088 Employee Termination Asset 2018 Benefits Impairments Total Research and development $ 272 $ 267 $ 539 Manufacturing and production 735 — 735 General and administrative 117 — 117 $ 1,124 $ 267 $ 1,391
Schedule of Accrual Activity for Employee Termination Benefits	The following table sets forth the accrual activity for employee termination benefits for the six months ended June 30, 2019 (in thousands). Balance at December 31, 2018 $ — Accruals 2,088 Payments (1,992 ) Balance at June 30, 2019 $ 96

Basis of Presentation - Additio

Basis of Presentation - Additional Information (Detail) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Maximum period for cash and highly liquid securities with original maturities			ninety days or less
Minimum period for marketable securities classified as available-for-sale with original maturities			more than ninety days
Common stock equivalents excluded from the calculation of diluted net income per share	6.2	7.2	6.6	7.2

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Total Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 23	$ 162	$ 4	$ 209
Research and development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	6	48	(44)	76
Manufacturing and production [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	0	0	0	(68)
General and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 17	$ 114	$ 48	$ 201

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based awards granted	0	0
Estimated value of stock-based awards, granted			$ 0.4
Unrecognized compensation cost related to unvested options	$ 0.1	$ 0.1
Unvested stock-based awards expected to be recognized, weighted-average period		1 year 3 months 18 days
Portion of stock-based awards granted from outstanding common shares			2.50%

Marketable Securities, Availa_3

Marketable Securities, Available for Sale - Summary of Available-for-Sale Marketable Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 30,865	$ 36,219
Unrealized Gain	42	0
Unrealized Loss	0	18
Market Value	30,907	36,201
U.S. treasuries [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	30,865	36,219
Unrealized Gain	42	0
Unrealized Loss	0	18
Market Value	$ 30,907	$ 36,201

Marketable Securities, Availa_4

Marketable Securities, Available for Sale - Additional Information (Detail)	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2019USD ($)
Investments Debt And Equity Securities [Abstract]
Available-for-sale securities maturing outside of one year	$ 0	$ 0
Realized gains or losses on sales of available-for-sale securities	0	0
Available-for-sale securities in a continuous material unrealized loss position longer than one year	$ 0	$ 0

Other Balance Sheet Accounts -

Other Balance Sheet Accounts - Summary of Accounts Payable and Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Employee compensation	$ 335	$ 1,768
Post-termination benefit accrual	96	0
Clinical trial accruals	111	1,000
Accounts payable	544	412
Other accrued liabilities	73	371
Total accounts payable and accrued expenses	$ 1,159	$ 3,551

Long-Term Investments - Additio

Long-Term Investments - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2019USD ($)
Investment [Line Items]
Auction rate securities held, at par value	$ 2.5
Investment and other income [Member]
Investment [Line Items]
Gain on sale	$ 0.4

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Cash Equivalents, Marketable Securities and Long-Term Investments Measured at Fair Value (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 41,085	$ 50,110
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	41,085	47,724
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	2,386
Money market funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	10,178	11,523
Money market funds [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	10,178	11,523
Money market funds [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Money market funds [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
U.S. treasuries [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	30,907	36,201
U.S. treasuries [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	30,907	36,201
U.S. treasuries [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
U.S. treasuries [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 0	0
Auction rate securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value		2,386
Auction rate securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value		0
Auction rate securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value		0
Auction rate securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value		$ 2,386

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investments	$ 0	$ 0

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Activity for Assets Measured at Fair Value Using Significant Unobservable Inputs (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Fair Value Disclosures [Abstract]
Balance at December 31, 2018	$ 2,386
Change in fair market value included in other comprehensive loss	83
Sale of Level 3 security	(2,469)
Balance at June 30, 2019	0
Total gains or losses for the period included in net loss attributable to the change in unrealized gains or losses relating to assets still held at the reporting date	$ 0

Astellas Out-License Agreemen_2

Astellas Out-License Agreements - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recognized	$ 0	$ 725	$ 0	$ 1,431
Collaborative Arrangement [Member] | Astellas Out-License Agreements [Member] | Contract Services [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue recognized		$ 700		$ 1,200

Facility Lease - Additional Inf

Facility Lease - Additional Information (Detail)	1 Months Ended
	Jul. 31, 2018USD ($)ft²	Jun. 30, 2019USD ($)ft²	Dec. 31, 2018USD ($)
Facility Lease [Line Items]
Receivables and other assets		$ 979,000	$ 1,128,000
Receivables and Other Assets [Member]
Facility Lease [Line Items]
Receivables and other assets		$ 400,000
Genopis Inc [Member]
Facility Lease [Line Items]
Sale of idle manufacturing assets	$ 1,700,000
Genopis Inc [Member] | California [Member]
Facility Lease [Line Items]
Area for leasing facility of research laboratory and office space | ft²	17,000	17,000
Renewal lease agreement expiry date	Dec. 31, 2018
Area of square feet agreed to sublease of facility | ft²	51,400
Long-term lease beginning date	Jan. 1, 2019
Facility lease cost	$ 0
Facility sublease expiration period	1 year
Sublease expiration date	Dec. 31, 2019

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended
	Mar. 31, 2019	Nov. 30, 2017	Mar. 31, 2019	Jun. 30, 2019
Stockholders Equity [Line Items]
Sale of common stock, preferred stock, debt securities and warrants				$ 40,000,000
Common Stock [Member]
Stockholders Equity [Line Items]
Pre-funded warrants to purchase common stock		7,234,285
Pre-funded warrants to purchase common stock, price per share		$ 1.74
Pre-funded warrants exercise price per share		$ 0.01
Warrants exercised	993,211		993,000
Warrants to purchase shares of common stock, outstanding				6,241,074
Public Offering [Member] | Common Stock [Member]
Stockholders Equity [Line Items]
Shares issued		9,194,286
Public offering, price per share		$ 1.75
Overallotment [Member] | Common Stock [Member]
Stockholders Equity [Line Items]
Shares issued		2,142,857
Public offering, price per share		$ 1.75

Related Party Transaction - Add

Related Party Transaction - Additional Information (Detail) - USD ($)	Apr. 04, 2017	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Sep. 30, 2018
Related Party Transaction [Line Items]
Contract revenue		$ 0	$ 725,000	$ 0	$ 1,431,000
Research Collaboration Agreement [Member] | AnGes MG, Inc [Member]
Related Party Transaction [Line Items]
Percentage of common stock outstanding	18.60%
Non- refundable amount receivable under research collaboration agreement	$ 750,000					$ 145,000
Contract revenue				$ 895,000

Restructuring Costs - Additiona

Restructuring Costs - Additional Information (Detail) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 31, 2018Employee	Jun. 30, 2019USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2018USD ($)
Restructuring Cost And Reserve [Line Items]
Restructuring charges		$ 600		$ 2,088
Number of staff reduced | Employee	40
One-time employee termination benefits					$ 1,100
Overhead costs associated with manufacturing facility		$ 0	$ 0	0	1,436
Intangible asset impairment charges				0	267
General and administrative [Member]
Restructuring Cost And Reserve [Line Items]
Overhead costs associated with manufacturing facility			$ 600		1,000
Intangible asset impairment charges				$ 0	$ 0

Restructuring Costs - Summary o

Restructuring Costs - Summary of Restructuring Charges (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Restructuring Cost And Reserve [Line Items]
Employee Termination Benefits	$ 2,088	$ 1,124
Asset Impairments	0	267
Total	2,088	1,391
Research and development [Member]
Restructuring Cost And Reserve [Line Items]
Employee Termination Benefits	2,018	272
Asset Impairments	0	267
Total	2,018	539
Manufacturing and production [Member]
Restructuring Cost And Reserve [Line Items]
Employee Termination Benefits		735
Asset Impairments		0
Total		735
General and administrative [Member]
Restructuring Cost And Reserve [Line Items]
Employee Termination Benefits	70	117
Asset Impairments	0	0
Total	$ 70	$ 117

Restructuring Costs - Schedule

Restructuring Costs - Schedule of Accrual Activity for Employee Termination Benefits (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Restructuring And Related Activities [Abstract]
Balance at December 31, 2018		$ 0
Accruals	$ 600	2,088
Payments		(1,992)
Balance at June 30, 2019	$ 96	$ 96

Merger Agreement - Additional I

Merger Agreement - Additional Information (Detail) - USD ($) $ in Millions	Jun. 02, 2019	Jun. 30, 2019
Common Stock [Member] | Brickell securityholders and NovaQuest [Member]
Business Acquisition [Line Items]
Percentage of shares expect to acquired	60.00%
Percentage of shares expect to acquired prior to merger	40.00%
Brickell Biotech, Inc., [Member] | NovaQuest Co-Investment Fund X, L.P. (“NovaQuest”) [Member]
Business Acquisition [Line Items]
Committed to provide near-term research and development funding	$ 25
Commitment expected to be paid	$ 5.6
Brickell Biotech, Inc., [Member] | NovaQuest Co-Investment Fund X, L.P. (“NovaQuest”) [Member] | NovaQuest Warrants [Member]
Business Acquisition [Line Items]
Percentage of warrant coverage on committed funding amount	10.00%
Warrant exercise price description		The number of shares of Vical common stock underlying the NovaQuest Warrants will be based on 10% warrant coverage on the $25.0 million NovaQuest funding commitment and the final exchange ratio for the Merger, or the Exchange Ratio, and the exercise price of the NovaQuest Warrants will be determined based on a 10% premium to the Brickell price per share of common stock implied value in the Merger, as adjusted for the Exchange Ratio.
Brickell Biotech, Inc., [Member] | NovaQuest Co-Investment Fund X, L.P. (“NovaQuest”) [Member] | Maximum [Member]
Business Acquisition [Line Items]
Committed to provide near-term research and development funding	$ 25
Invoiced Research and Development Expenses [Member] | Brickell Biotech, Inc., [Member] | NovaQuest Co-Investment Fund X, L.P. (“NovaQuest”) [Member]
Business Acquisition [Line Items]
Percentage of commitment amount expected to be paid	67.00%