Cidara Therapeutics (CDTX) 10-Q 13 May 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2021	Apr. 30, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	001-36912
Entity Registrant Name	CIDARA THERAPEUTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-1537286
Entity Address, Address Line One	6310 Nancy Ridge Drive,
Entity Address, Address Line Two	Suite 101
Entity Address, City or Town	San Diego,
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92121
City Area Code	(858)
Local Phone Number	752-6170
Title of 12(b) Security	Common Stock, Par Value $0.0001 Per Share
Trading Symbol	CDTX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		48,289,795
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001610618
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 42,863	$ 35,912
Restricted cash	5,926	7,037
Accounts receivable	11	11,175
Prepaid expenses and other current assets	2,501	3,067
Total current assets	51,301	57,191
Property and equipment, net	285	342
Operating lease right-of-use asset	663	868
Other assets	1,961	2,023
Total assets	54,210	60,424
Current liabilities:
Accounts payable	3,215	4,568
Accrued liabilities	9,047	7,959
Accrued compensation and benefits	5,661	4,210
Current deferred revenue	15,411	13,865
Current portion of term loan	5,916	7,023
Current portion of lease liability	716	939
Total current liabilities	39,966	38,564
Long-term deferred revenue	12,352	11,145
Total liabilities	52,318	49,709
Commitments and contingencies
Stockholders' equity:
Preferred stock
Common stock, $0.0001 par value; 200,000,000 shares authorized at March 31, 2021 and December 31, 2020; 48,288,670 and 44,876,408 shares issued and outstanding at March 31, 2021 and December 31, 2020, respectively	5	4
Additional paid-in capital	354,879	345,411
Accumulated deficit	(352,992)	(334,700)
Total stockholders' equity	1,892	10,715
Total liabilities and stockholders' equity	54,210	60,424
Series X Convertible Preferred Stock
Stockholders' equity:
Preferred stock	0	0
Total stockholders' equity	$ 0	$ 0

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) (unaudited) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	48,288,670	44,876,408
Common stock, shares outstanding (in shares)	48,288,670	44,876,408
Series X Convertible Preferred Stock
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	1,096,519	1,044,278
Preferred stock, shares outstanding (in shares)	1,096,519	1,044,278

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue	$ 2,408	$ 2,530
Operating expenses:
Research and development	15,849	12,996
General and administrative	4,781	4,095
Total operating expenses	20,630	17,091
Loss from operations	(18,222)	(14,561)
Other income (expense):
Interest income (expense), net	(70)	22
Total other income (expense), net	(70)	22
Net loss and comprehensive loss	(18,292)	(14,539)
Recognition of beneficial conversion feature	0	(2,762)
Net loss attributable to common shareholders	$ (18,292)	$ (17,301)
Basic net loss per common share (in dollars per share)	$ (0.39)	$ (0.46)
Diluted net loss per common share (in dollars per share)	$ (0.39)	$ (0.46)
Shares used to compute basic net loss per share (in shares)	46,967,213	37,856,338
Shares used to compute diluted net loss per share (in shares)	46,967,213	37,856,338
Collaboration revenue
Revenue	$ 2,408	$ 2,530

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating activities:
Net loss	$ (18,292)	$ (14,539)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	57	71
Stock-based compensation	879	1,246
Non-cash interest expense	3	1
Amortization of debt issuance costs	1	0
Operating lease right-of-use assets and liabilities, net	(17)	(12)
Changes in assets and liabilities:
Accounts receivable	11,164	(307)
Prepaid expenses, other current assets, and other assets	461	(1,021)
Accounts payable and accrued liabilities	(253)	379
Accrued compensation and benefits	1,451	(1,422)
Deferred revenue	2,753	476
Net cash used in operating activities	(1,793)	(15,128)
Investing activities:
Purchases of property and equipment	(12)	(36)
Net cash used in investing activities	(12)	(36)
Financing activities:
Proceeds from issuance of common and Series X Preferred stock pursuant to rights offering, net of issuance costs	0	29,186
Proceeds from public offering of common stock, net of issuance costs	8,755	19
Proceeds from exercise of stock options	1	5
Principal repayments of Term Loan	(1,111)	0
Net cash provided by financing activities	7,645	29,210
Net increase in cash, cash equivalents, and restricted cash	5,840	14,046
Cash, cash equivalents, and restricted cash at beginning of period	42,949	60,268
Cash, cash equivalents, and restricted cash at end of period	48,789	74,314
Supplemental disclosure of cash flows:
Interest paid	$ 75	$ 139

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Changes in Convertible Preferred Stock and Stockholders' Equity (unaudited) - USD ($) $ in Thousands	Total	Rights Offering, February 2020	Series X Convertible Preferred Stock	Series X Convertible Preferred StockRights Offering, February 2020	Common Stock	Common StockRights Offering, February 2020	Additional Paid-In Capital	Additional Paid-In CapitalRights Offering, February 2020	Accumulated Deficit
Balance, beginning (in shares) at Dec. 31, 2019			565,231		33,838,466
Balance, beginning at Dec. 31, 2019	$ 37,835		$ 0		$ 3		$ 297,659		$ (259,827)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)				531,288	7,600	6,639,307
Issuance of common stock	19	$ 29,186				$ 1	19	$ 29,185
Recognition of beneficial conversion feature	0						2,762		(2,762)
Issuance of common stock for exercise of stock options (in shares)					1,834
Issuance of common stock for exercise of options	5						5
Issuance of common stock for restricted share units vested (in shares)					72,304
Issuance of common stock for restricted share units vested	0						0
Stock-based compensation	1,246						1,246
Net loss	(14,539)								(14,539)
Balance, ending (in shares) at Mar. 31, 2020			1,096,519		40,559,511
Balance, ending at Mar. 31, 2020	53,752		$ 0		$ 4		330,876		(277,128)
Balance, beginning (in shares) at Dec. 31, 2020			1,044,278		44,876,408
Balance, beginning at Dec. 31, 2020	10,715		$ 0		$ 4		345,411		(334,700)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)					3,327,706
Issuance of common stock	$ 8,589				$ 1		8,588
Issuance of common stock for exercise of stock options (in shares)	486				486
Issuance of common stock for exercise of options	$ 1						1
Issuance of common stock for restricted share units vested (in shares)					84,070
Issuance of common stock for restricted share units vested	0						0
Stock-based compensation	879						879
Net loss	(18,292)								(18,292)
Balance, ending (in shares) at Mar. 31, 2021			1,044,278		48,288,670
Balance, ending at Mar. 31, 2021	$ 1,892		$ 0		$ 5		$ 354,879		$ (352,992)

THE COMPANY AND BASIS OF PRESEN

THE COMPANY AND BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
THE COMPANY AND BASIS OF PRESENTATION	THE COMPANY AND BASIS OF PRESENTATION Description of Business Cidara Therapeutics, Inc., or the Company, was originally incorporated in Delaware in December 2012 as K2 Therapeutics, Inc., and its name was changed to Cidara Therapeutics, Inc. in July 2014. The Company is a biotechnology company focused on the discovery, development and commercialization of long-acting therapeutics designed to transform the standard of care for patients facing serious fungal or viral infections. The Company’s lead product candidate is rezafungin acetate, an intravenous formulation of a novel echinocandin. Rezafungin is being developed as a once-weekly, high-exposure therapy for the first-line treatment and prevention of serious, invasive fungal infections. In addition, the Company is using its Cloudbreak® antiviral platform to develop Antiviral Conjugates, or AVCs, for the prevention and treatment of influenza and other viral infections, including RSV, HIV and the SARS-CoV-2 strains causing COVID-19. The Company formed wholly-owned subsidiaries, Cidara Therapeutics UK Limited, in England, and Cidara Therapeutics (Ireland) Limited, in Ireland, in March 2016 and October 2018, respectively, for the purpose of developing its product candidates in Europe. Basis of Presentation The Company has a limited operating history and the sales and income potential of the Company’s business and market are unproven. The Company has experienced net losses and negative cash flows from operating activities since its inception. At March 31, 2021, the Company had an accumulated deficit of $353.0 million. The Company expects to continue to incur net losses into the foreseeable future. Successful transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support the Company’s cost structure. At March 31, 2021, the Company had cash, cash equivalents and restricted cash of $48.8 million. Based on the Company’s current business plan, management believes that existing cash and cash equivalents will not be sufficient to fund the Company’s obligations for twelve months from the issuance of these financial statements. The Company’s ability to execute its operating plan depends on its ability to obtain additional funding through equity offerings, debt financings or potential licensing and collaboration arrangements. The accompanying consolidated financial statements have been prepared assuming the Company will continue as a going concern, which contemplates the realization of assets and settlement of liabilities in the normal course of business. However, the Company’s current working capital, anticipated operating expenses and net losses and the uncertainties surrounding its ability to raise additional capital as needed, as discussed below, raise substantial doubt about its ability to continue as a going concern for a period of one year following the date that these financial statements are issued. The consolidated financial statements do not include any adjustments for the recovery and classification of assets or the amounts and classification of liabilities that might be necessary should the Company be unable to continue as a going concern. The Company plans to continue to fund its losses from operations through cash and cash equivalents on hand, as well as through future equity offerings, debt financings, other third party funding, and potential licensing or collaboration arrangements. There can be no assurance that additional funds will be available when needed from any source or, if available, will be available on terms that are acceptable to the Company. Even if the Company raises additional capital, it may also be required to modify, delay or abandon some of its plans which could have a material adverse effect on the Company’s business, operating results and financial condition and the Company’s ability to achieve its intended business objectives. Any of these actions could materially harm the Company’s business, results of operations and future prospects. In addition to the foregoing, the Company is monitoring closely the impact of the COVID-19 pandemic on its business and has taken steps designed to protect the health and safety of its employees while continuing its operations. Given the level of uncertainty regarding the duration and impact of the COVID-19 pandemic on capital markets and the U.S. economy, the Company is currently unable to assess the impact of the COVID-19 pandemic on its future access to capital. The Company is continuing to monitor the spread of COVID-19 and its potential impact on the Company's operations. The full extent to which the COVID-19 pandemic will impact the Company's business, results of operations, financial condition, clinical trials, and preclinical research will depend on future developments that are highly uncertain, including actions taken to contain or treat COVID-19 and their effectiveness, as well as the economic impact on national and international markets. Unaudited Interim Financial Data The accompanying condensed consolidated financial statements are unaudited and have been prepared by the Company in accordance with U.S. generally accepted accounting principles, or GAAP, as found in the Accounting Standards Codification, or ASC, of the Financial Accounting Standards Board, or FASB. Certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. These interim condensed consolidated financial statements, in the opinion of management, reflect all normal recurring adjustments necessary for a fair presentation of the Company’s financial position and results of operations for the interim periods ended March 31, 2021 and 2020. Basis of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of expenses during the reporting period. The Company evaluates its estimates and assumptions on an ongoing basis. The most significant estimates in the Company’s consolidated financial statements relate to estimating the fair value of the Company’s stock options, estimated collaboration expenses and incurred expenses related to the Mundipharma Collaboration Agreement (as defined below), and certain accruals, including those related to nonclinical and clinical activities. Although the estimates are based on the Company’s knowledge of current events, comparable companies, and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions. Segment Information Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, the Chief Executive Officer, in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business as one operating segment.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Cash, Cash Equivalents and Restricted Cash The Company considers all short-term investments purchased with a maturity of three months or less when acquired to be cash equivalents. Restricted cash represents cash that the Company is required to maintain on hand in order to maintain compliance with an operating covenant in the Third Amendment to the Company's Loan Agreement with Pacific Western Bank. See Note 4 for additional information. Accounts Receivable Accounts receivable are recorded at their net invoice value and are not interest bearing. The Company reserves specific receivables when collectibility is no longer probable. These reserves are re-evaluated on a regular basis and are adjusted, as needed. Once a receivable is deemed to be uncollectible, such balance is recorded as an allowance for credit losses. No such allowance existed at March 31, 2021 or December 31, 2021. Property and Equipment The Company records property and equipment at cost, which consists of lab equipment, computer equipment and software, office equipment, furniture and fixtures and leasehold improvements. Property and equipment is depreciated using the straight-line method over the estimated useful lives (generally three Income Taxes The Company follows ASC 740, Income Taxes , or ASC 740, in reporting deferred income taxes. ASC 740 requires a company to recognize deferred tax assets and liabilities for expected future income tax consequences of events that have been recognized in the Company’s consolidated financial statements. Under this method, deferred tax assets and liabilities are determined based on temporary differences between financial statement carrying amounts and the tax basis of assets and liabilities using enacted tax rates in the years in which the temporary differences are expected to reverse. Valuation allowances are provided if, based on the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertain tax positions pursuant to ASC 740, which prescribes a recognition threshold and measurement process for financial statement recognition of uncertain tax positions taken or expected to be taken in a tax return. If the tax position meets this threshold, the benefit to be recognized is measured as the tax benefit having the highest likelihood of being realized upon ultimate settlement with the taxing authority. The Company recognizes interest accrued related to unrecognized tax benefits and penalties in the provision for income taxes. Revenue Recognition The Company recognizes revenue is accordance with ASC Topic 606, Revenue from Contracts with Customers , or Topic 606, which applies to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. Under Topic 606, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration that the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Topic 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations, and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. In a contract with multiple performance obligations, the Company must develop estimates and assumptions that require judgment to determine the underlying stand-alone selling price for each performance obligation, which determines how the transaction price is allocated among the performance obligations. The estimation of the stand-alone selling price(s) may include estimates regarding forecasted revenues or costs, development timelines, discount rates, and probabilities of technical and regulatory success. The Company evaluates each performance obligation to determine if it can be satisfied at a point in time or over time. Any change made to estimated progress towards completion of a performance obligation and, therefore, revenue recognized will be recorded as a change in estimate. In addition, variable consideration must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price. If a license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in a contract, the Company recognizes revenues from the transaction price allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from the allocated transaction price. The Company evaluates the measure of progress at each reporting period and, if necessary, adjusts the measure of performance and related revenue or expense recognition as a change in estimate. At the inception of each arrangement that includes milestone payments, the Company evaluates whether the milestones are considered probable of being reached. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s or a collaboration partner’s control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. At the end of each reporting period, the Company re-evaluates the probability of achievement of milestones that are within its or a collaboration partner’s control, such as operational developmental milestones and any related constraint, and, if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which will affect collaboration revenues and earnings in the period of adjustment. Revisions to the Company’s estimate of the transaction price may also result in negative collaboration revenues and earnings in the period of adjustment. For arrangements that include sales-based royalties, including commercial milestone payments based on the level of sales, and a license is deemed to be the predominant item to which the royalties relate, the Company will recognize revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied, or partially satisfied. To date, the Company has not recognized any royalty revenue from collaborative arrangements. In September 2019, the Company entered into a Collaboration and License Agreement, or the Mundipharma Collaboration Agreement, with Mundipharma Medical Company, or Mundipharma. The Company concluded that there were three significant performance obligations under the Mundipharma Collaboration Agreement: the license, the research and development services, and the clinical supply services, and that the obligations are distinct from each other. Revenue associated with the license was recognized upon delivery in September 2019. The Company concluded that progress towards completion of the research and development and clinical supply performance obligations related to the Mundipharma Collaboration Agreement is best measured in an amount proportional to the collaboration expenses incurred and the total estimated collaboration expenses. The Company periodically reviews and updates the estimated collaboration expenses, when appropriate, which may adjust revenue recognized for the period. While such changes to the Company’s estimates have no impact on the Company’s reported cash flows, the amount of revenue recorded in the period could be materially impacted. The transaction price to be recognized as revenue under the Mundipharma Collaboration Agreement consists of the upfront payment and estimated reimbursable research and development and clinical supply costs. Potential future payments for variable consideration, such as clinical, regulatory or commercial milestones, will be recognized when it is probable that, if recorded, a significant reversal will not take place. Potential future royalty payments will be recorded as revenue when the associated sales occur. See Note 7 for additional information. Research and Development Costs Research and development expenses consist of wages, benefits and stock-based compensation charges for research and development employees, scientific consultant fees, facilities and overhead expenses, laboratory supplies, manufacturing expenses, and nonclinical and clinical trial costs. The Company accrues nonclinical and clinical trial expenses based on work performed, which relies on estimates of total costs incurred based on patient enrollment, completion of studies, and other events. Costs incurred in purchasing technology assets and intellectual property are charged to research and development expense if the technology has not been conclusively proven to be feasible and has no alternative future use. Preclinical and Clinical Trial Accruals The Company makes estimates of its accrued expenses as of each balance sheet date in the financial statements based on the facts and circumstances known at that time. Accrued expenses for preclinical studies and clinical trials are based on estimates of costs incurred and fees that may be associated with services provided by contract research organizations, or CROs, clinical trial investigational sites and other clinical trial-related activities. Payments under certain contracts with such parties depend on factors such as successful enrollment of patients, site initiation and the completion of clinical trial milestones. In accruing for these services, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If possible, the Company obtains information regarding unbilled services directly from these service providers. However, the Company may be required to estimate these services based on other available information. If the Company underestimates or overestimates the activities or fees associated with a study or service at a given point in time, adjustments to research and development expenses may be necessary in future periods. Historically, estimated accrued liabilities have approximated actual expense incurred. Subsequent changes in estimates may result in a material change in accruals. Stock-Based Compensation The Company accounts for stock-based compensation expense related to stock options, Restricted Stock Units, or RSUs, Performance-based RSUs, or PRSUs, and Employee Stock Purchase Plan rights by estimating the fair value on the date of grant using the Black-Scholes option pricing model. For awards subject to time-based vesting conditions, including those with a graded vesting schedule, stock-based compensation expense is recognized using the straight-line method. For performance-based awards to employees, (i) the fair value of the award is determined on the grant date, (ii) the Company assesses the probability of the individual performance milestones under the award being achieved and (iii) the fair value of the shares subject to the milestone is expensed over the implicit service period commencing once management believes the performance criteria is probable of being met. The Company recognizes forfeitures related to stock-based compensation as they occur. The Company estimates the fair value of stock option awards to employees and non-employees using the Black-Scholes option pricing model, which requires the input of highly subjective assumptions, including (a) the risk-free interest rate, (b) the historical volatility of the Company's stock, (c) the expected term of the award, and (d) the expected dividend yield. In January 2021, the Company began to compute the historical volatility data using the daily close prices for the Company's common stock during the equivalent period of the calculated expected term of the Company's stock-based awards. The Company estimated the expected life of employee stock options using the “simplified” method, whereby the expected life equals the average of the vesting term and the original contractual term of the option. The risk-free interest rates for periods within the expected life of the option are based on the yields of zero-coupon U.S. treasury securities. Net Loss Per Share Basic net loss per share is calculated by dividing the net loss allocable to common shares by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss allocable to common shares by the weighted-average number of common shares and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. Dilutive common stock equivalents are comprised of warrants, Series X Convertible Preferred Stock, as well as RSUs, PRSUs and options outstanding under the Company’s stock option plans. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding. The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because doing so would be anti-dilutive (in common stock equivalent shares): Three Months Ended 2021 2020 Common stock warrants 12,517,328 12,517,328 Series X Convertible Preferred stock 10,442,780 10,965,190 Common stock options, RSUs and PRSUs issued and outstanding 8,648,708 6,658,011 Total 31,608,816 30,140,529 Fair Value of Financial Instruments The Company follows ASC 820-10 issued by the FASB with respect to fair value reporting for financial assets and liabilities. The guidance defines fair value, provides guidance for measuring fair value and requires certain disclosures. The guidance does not apply to measurements related to share-based payments. The guidance discusses valuation techniques such as the market approach (comparable market prices), the income approach (present value of future income or cash flow), and the cost approach (cost to replace the service capacity of an asset or replacement cost). The guidance establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. The Company’s financial instruments consist of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, accrued liabilities, and a term loan. Fair value estimates of these instruments are made at each reporting period end based on relevant market information. These estimates may be subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. The carrying amount of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, and accrued liabilities are generally considered to be representative of their respective fair values because of the short-term nature of those instruments. The Company believes that the fair value of long-term debt approximates its carrying value. Recently Issued Accounting Standards Recently Issued Accounting Standards Not Yet Adopted In August 2020, the FASB issued ASU 2020-06, "Accounting for Convertible Instruments and Contracts in an Entity's Own Equity," simplifies the accounting for certain convertible instruments by removing the separation models for convertible debt with a cash conversion feature or convertible instruments with a beneficial conversion feature. As a result, more convertible debt instruments will be reported as a single liability instrument with no separate accounting for embedded conversion features. Additionally, this ASU amends the diluted EPS calculation for convertible instruments by requiring the use of the if-converted method. The treasury stock method is no longer available. Entities may adopt this ASU using either a full or modified retrospective approach, and it is effective for interim and annual reporting periods beginning after December 15, 2021. Early adoption is permitted for interim and annual reporting periods beginning after December 15, 2020. The Company is assessing the impact the adoption of this ASU will have on its financial statements. Recently Adopted Accounting Standards In December 2019, the FASB issued ASU 2019-12, "Simplifying the Accounting for Income Taxes," which eliminates certain exceptions within ASC 740, Income Taxes, and clarifies other aspects of the current guidance to promote consistency among reporting entities. The Company adopted ASU 2019-12 effective January 1, 2021. The adoption of this standard did not have a material impact on the Company's financial statements.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS The Company follows ASC 820-10, Fair Value Measurements and Disclosures, which among other things, defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement determined based on assumptions that market participants would use in pricing an asset or liability. The carrying amounts of accounts payable and accrued liabilities are considered to be representative of their respective fair values because of the short-term nature of those instruments. Based on the borrowing rates available to the Company for loans with similar terms, which is considered a Level 2 input as described below, the Company believes that the fair value of long-term debt approximates its carrying value. As a basis for considering such assumptions, a three-tier fair value hierarchy has been established, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices (unadjusted) in active markets for identical assets or liabilities; Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and Level 3: Unobservable inputs for which there is little or no market data, which require the reporting entity to develop its own assumptions, which reflect those that a market participant would use. The Company classifies investments in money market funds within Level 1 as the prices are available from quoted prices in active markets. None of the Company’s non-financial assets or liabilities are recorded at fair value on a non-recurring basis. No transfers between levels have occurred during the periods presented. The following tables summarize the Company’s financial instruments measured at fair value on a recurring basis (in thousands): TOTAL LEVEL 1 LEVEL 2 LEVEL 3 March 31, 2021 Assets: Cash and money market funds $ 42,863 $ 42,863 $ — $ — Restricted cash and money market accounts 5,926 5,926 — — Total assets at fair value $ 48,789 $ 48,789 $ — $ — December 31, 2020 Assets: Cash and money market accounts $ 35,912 $ 35,912 $ — $ — Restricted cash and money market accounts 7,037 7,037 — — Total assets at fair value $ 42,949 $ 42,949 $ — $ —

DEBT

DEBT	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
DEBT	DEBT Term Loans — On October 3, 2016, the Company entered into a loan and security agreement, or the Loan Agreement, with Pacific Western Bank, as the collateral agent and a lender, or the Lender, pursuant to which the Company has borrowed $10.0 million from the Lender, or the Term A Loan. At March 31, 2021, the Term A Loan bears interest at 4.5% and mature on July 3, 2022. On March 16, 2021, the Company and the Lender entered into a Fourth Amendment to the Loan Agreement, which modified certain debt covenants under the original agreement but had no impact on current or future cash flows. Upon the occurrence of certain events, including but not limited to the Company’s failure to satisfy its payment obligations under the Loan Agreement, the breach of certain of its other covenants under the Loan Agreement or the occurrence of a material adverse change, the Lender has the right, among other remedies, to declare all principal and interest and other amounts due to the Lender under the Loan Agreement immediately due and payable. The principal payments due under the Loan Agreement have been classified as a current liability at March 31, 2021 and December 31, 2020 due to the considerations discussed in Note 1 and the assessment that the material adverse change clause under the 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. As of March 31, 2021, future principal payments due under the Third Amendment of the Term A Loan are as follows (in thousands): Year ended: December 31, 2021 $ 3,333 December 31, 2022 2,593 Total future principal payments due under the Term A Loan $ 5,926

STOCKHOLDERS_ EQUITY

STOCKHOLDERS’ EQUITY	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
STOCKHOLDERS’ EQUITY	STOCKHOLDERS’ EQUITY 2020 Rights Offering On January 22, 2020, the Company initiated a rights offering to raise gross proceeds of $30.0 million through the distribution of subscription rights to holders of its common stock, Series X Preferred Stock, and warrants to purchase common stock issued on May 21, 2018, or the Rights Offering. On February 12, 2020, the Company sold 6,639,307 shares of common stock and 531,288 shares of Series X Preferred Stock for $2.51 and $25.10 per share, respectively, for aggregate gross proceeds of $30.0 million. Total offering costs of $0.8 million were offset against the proceeds from the sale of common stock for total net proceeds of $29.2 million. The Rights Offering was fully backstopped by Biotechnology Value Fund, L.P. and Stonepine Capital, LP. With respect to the Series X Convertible Preferred Stock, because the effective conversion price on the commitment date was below the fair value of the common stock at the date of issuance, a beneficial conversion feature with a calculated fair value of $2.8 million existed at the issuance date. As the Series X Convertible Preferred Stock is fully convertible at issuance, the full $2.8 million was recorded at issuance as a deemed dividend on February 12, 2020. This non-cash deemed dividend impacted accumulated deficit and additional paid in capital at March 31, 2020 and net loss attributable to common stockholders and net loss attributable to common stockholders per share for the year ended March 31, 2020. With respect to the common stock, because the purchase price was below fair value on the issuance date, a bonus element exists at the issuance date. Basic and diluted net loss per common share and shares used to compute basic and diluted net loss per common share have been retroactively adjusted for all periods presented to reflect this bonus element. Controlled Equity Sales Agreement In September 2019, the Company began to sell shares of common stock under a controlled equity sales agreement with Cantor Fitzgerald & Co, or the Sales Agreement. During the three months ended March 31, 2021 and March 31, 2020, the company sold 3,327,706 and 7,600 shares of common stock, respectively, for net proceeds of approximately $8.6 million and $19.0 thousand, respectively, after deducting placement agent fees. Preferred Stock Under the amended and restated certificate of incorporation, the Company’s board of directors has the authority, without further action by the stockholders, to issue up to 10,000,000 shares of preferred stock in one or more series, to establish from time to time the number of shares to be included in each such series, to fix the rights, preferences and privileges of the shares of each wholly unissued series and any qualifications, limitations or restrictions thereon and to increase or decrease the number of shares of any such series, but not below the number of shares of such series then outstanding. The Company had 10,000,000 shares of preferred stock authorized at March 31, 2021. In May 2018, the Company designated 5,000,000 shares of preferred stock as Series X Convertible Preferred Stock with a par value of $0.0001 per share. On August 12, 2020, at the request of certain holders, 52,241 shares of the Company’s Series X Convertible Preferred Stock were converted to an aggregate of 522,410 shares of the Company’s common stock. The specific terms of the Series X Convertible Preferred Stock are as follows: Conversion: Each share of Series X Convertible Preferred Stock is convertible at the option of the holder into 10 shares of common stock. Holders are not permitted to convert Series X Convertible Preferred Stock into common stock if, after conversion, the holder, its affiliates, and any other person whose beneficial ownership of common stock would be aggregated with the holder's for purposes of Section 13(d) or Section 16 of the Exchange Act, would beneficially own more than 9.99% of the number of shares of common stock outstanding immediately after the conversion. Dividends: Holders of Series X Convertible Preferred Stock are not entitled to receive any dividends except to the extent that dividends are paid on the Company's common stock. If dividends are paid on shares of common stock, holders of Series X Convertible Preferred Stock are entitled to participate in such dividends on an as-converted basis. Liquidation: Upon the liquidation, dissolution, or winding up of the company, each holder of Series X Convertible Preferred Stock will participate pari passu with any distribution of proceeds to holders of common stock. Voting: Shares of Series X Convertible Preferred Stock will generally have no voting rights, except as required by law and except that the consent of the holders of a majority of the outstanding Series X Convertible Preferred Stock will be required to amend the terms of the Series X Convertible Preferred Stock , if such action would adversely alter or change the preferences, rights, privileges or powers of, or restrictions provided for the benefit of the Series X Convertible Preferred Stock, or to increase or decrease (other than by conversion) the number of authorized shares of Series X Convertible Preferred Stock. The Company evaluated the Series X Convertible Preferred Stock for liability or equity classification under ASC 480, Distinguishing Liabilities from Equity , and determined that equity treatment was appropriate because the Series X Convertible Preferred Stock did not meet the definition of liability instruments defined thereunder as convertible instruments. Specifically, the Series X Convertible Preferred Stock does not meet the criteria for classification as an ASC 480 liability. As such, the Series X Convertible Preferred Stock is recorded as permanent equity. Additionally, the Series X Convertible Preferred Stock is not redeemable for cash or other assets (i) on a fixed or determinable date, (ii) at the option of the holder, and (iii) upon the occurrence of an event that is not solely within control of the Company. Common Stock The Company had 200,000,000 shares of common stock authorized as of March 31, 2021. Holders of outstanding shares of common stock are entitled to one vote for each share held of record on all matters submitted to a vote of the holders of common stock. Subject to the rights of the holders of any class of the Company’s capital stock having any preference or priority over common stock, the holders of common stock are entitled to receive dividends that are declared by the Company’s board of directors out of legally available funds. In the event of a liquidation, dissolution or winding-up, the holders of common stock are entitled to share ratably in the net assets remaining after payment of liabilities, subject to prior rights of preferred stock, if any, then outstanding. The common stock has no preemptive rights, conversion rights, redemption rights or sinking fund provisions, and there are no dividends in arrears or default. All shares of common stock have equal distribution, liquidation and voting rights, and have no preferences or exchange rights. Common Stock Warrants As of March 31, 2021 and December 31, 2020, warrants to purchase 12,517,328 shares of common stock were outstanding at a weighted average exercise price of $6.82 per share. Common Stock Reserved for Future Issuance Common stock reserved for future issuance is as follows (in common stock equivalent shares): March 31, December 31, Common stock warrants 12,517,328 12,517,328 Series X Convertible Preferred Stock 10,442,780 10,442,780 Common stock options, RSUs and PRSUs issued and outstanding 8,648,708 6,787,033 Authorized for future stock awards under the Company's option plans 2,642,065 2,813,131 Authorized for future issuance under the ESPP 969,899 521,986 Total 35,220,780 33,082,258

EQUITY INCENTIVE PLANS

EQUITY INCENTIVE PLANS	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
EQUITY INCENTIVE PLANS	EQUITY INCENTIVE PLANS 2020 Inducement Incentive Plan and 2015 Equity Incentive Plan In December 2020, the Company's board of directors approved and adopted the 2020 Inducement Incentive Plan, or 2020 IIP. Under the 2020 IIP, the Company may grant stock options, stock appreciation rights, restricted stock, RSUs, and other awards to individuals who were not previously employees or directors of the Company, or who are returning to employment following a bona fide period of non-employment with the Company, as an inducement material to such persons entering into employment with the Company. In March 2015, the Company’s board of directors and stockholders approved and adopted the 2015 Equity Incentive Plan, or 2015 EIP. Under the 2015 EIP, the Company may grant stock options, stock appreciation rights, restricted stock, RSUs, and other awards to individuals who are employees, officers, directors or consultants of the Company. The number of shares of stock available for issuance under the 2015 EIP is automatically increased each January 1 by 4% of the outstanding number of shares of the Company’s common stock on the immediately preceding December 31 or such lesser number as determined by the Company’s board of directors. Terms of stock award agreements, including vesting requirements, are determined by the board of directors, subject to the provisions of the 2020 IIP and 2015 EIP. Stock options granted by the Company generally vest over a three 2015 Employee Stock Purchase Plan In March 2015, the Company’s board of directors and stockholders approved and adopted the 2015 Employee Stock Purchase Plan, or the ESPP. The number of shares of stock available for issuance under the ESPP will be automatically increased each January 1 by the lesser of (i) 1% of the outstanding number of shares of the Company’s common stock on the immediately preceding December 31, (ii) 490,336 shares, or (iii) such lesser number as determined by the Company’s board of directors. The ESPP allows substantially all employees to purchase the Company’s common stock through a payroll deduction at a price equal to 85% of the lower of the fair market value of the stock as of the beginning or the end of each purchase period. An employee’s payroll deductions under the ESPP are limited to 15% of the employee’s eligible compensation. During the three months ended March 31, 2021 and 2020, no shares were issued pursuant to the ESPP. Restricted Stock Units The following table summarizes RSU and PRSU activity during the three months ended March 31, 2021: Number of Weighted Average Grant Date Fair Value Outstanding at December 31, 2020 428,235 $ 3.55 RSUs and PRSUs granted 125,925 2.56 RSUs and PRSUs vested (100,558) 3.41 RSUs and PRSUs canceled (2,125) 2.27 Outstanding at March 31, 2021 451,477 $ 3.31 The weighted-average grant date fair value of RSUs and PRSUs granted during the three months ended March 31, 2020 was $4.24 per share. The total fair value of RSUs and PRSUs vested during the three months ended March 31, 2021 and March 31, 2020 was approximately $0.3 million and $0.3 million, respectively. At March 31, 2021, estimated unrecognized compensation expense related to RSUs and PRSUs grants was approximately $1.5 million. Stock Options The following table summarizes stock option activity during the three months ended March 31, 2021: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life in Years Total Aggregate Intrinsic Value (in thousands) Outstanding at December 31, 2020 6,358,798 $ 3.59 7.04 $ 55 Options granted 1,894,850 2.55 Options exercised (486) 1.98 Options canceled (55,931) 4.34 Outstanding at March 31, 2021 8,197,231 $ 3.35 7.56 $ 1,826 Vested and expected to vest at March 31, 2021 8,197,231 $ 3.35 7.56 $ 1,826 Exercisable at March 31, 2021 4,401,525 $ 4.10 6.21 $ 806 The intrinsic value of a stock option is the difference between the market price of the common stock at the measurement date and the exercise price of the option. Stock-based compensation expense recognized for restricted shares, RSUs, PRSUs, stock options, and the ESPP has been reported in the statements of operations as follows (in thousands): Three Months Ended 2021 2020 Research and development $ 391 $ 601 General and administrative 488 645 Total $ 879 $ 1,246 The weighted-average grant date fair value of stock options granted by the Company during the three months ended March 31, 2021 and March 31, 2020 was $1.51 and $1.39, respectively, per share. The total intrinsic value of stock options exercised during the three months ended March 31, 2021 and March 31, 2020 was immaterial. As of March 31, 2021, total unrecognized share-based compensation expense related to unvested stock options was approximately $5.6 million. This unrecognized compensation cost is expected to be recognized over a weighted-average period of approximately 2.3 years. As of March 31, 2021, total unrecognized compensation expense related to the ESPP was approximately $0.1 million. This unrecognized compensation cost is expected to be recognized over approximately 0.5 years.

SIGNIFICANT AGREEMENTS AND CONT

SIGNIFICANT AGREEMENTS AND CONTRACTS	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
SIGNIFICANT AGREEMENTS AND CONTRACTS	SIGNIFICANT AGREEMENTS AND CONTRACTS Mundipharma Collaboration Agreement On September 3, 2019, the Company entered into the Mundipharma Collaboration Agreement with Mundipharma, a related party, for a strategic collaboration to develop and commercialize rezafungin in an intravenous formulation, or the Licensed Product for the treatment and prevention of invasive fungal infections. Under the Mundipharma Collaboration Agreement, the Company is responsible for leading the conduct of an agreed global development plan, or the Global Development Plan, that includes the Company’s ongoing Phase 3 pivotal clinical trial of the Licensed Product for the treatment of candidemia and/or invasive candidiasis, or the ReSTORE Trial, and the Company’s planned Phase 3 pivotal clinical trial of the Licensed Product for the prophylaxis of invasive fungal infections in adult allogeneic blood and marrow transplant recipients, or the ReSPECT Trial, as well as specified GLP-compliant non‑clinical studies and chemistry, manufacturing and controls, or CMC, development activities for the Licensed Product. Mundipharma is responsible for performing all development activities, other than Global Development Plan activities, that may be necessary to obtain and maintain regulatory approvals for the Licensed Product in the Mundipharma Territory, at Mundipharma’s sole cost. Pursuant to the Mundipharma Collaboration Agreement, the Company granted Mundipharma an exclusive, royalty‑bearing license to develop, register and commercialize the Licensed Product outside of the United States and Japan, or the Mundipharma Territory, subject to the Company’s retained right to lead a global development program for the Licensed Product in both the Mundipharma Territory and in the United States and Japan, or the Company Territory, as described below. The Company also granted Mundipharma an option to obtain exclusive licenses to develop, register and commercialize rezafungin in a formulation for subcutaneous administration, or Subcutaneous Product, and in formulations for other modes of administration, or Other Products, in the Mundipharma Territory, subject to similar retained rights of the Company to conduct mutually agreed global development activities for such products. In addition, the Company granted Mundipharma a co‑exclusive, worldwide license to manufacture the Licensed Product and rezafungin. Until the seventh anniversary of the first commercial sale of the Licensed Product in the Mundipharma Territory, each party has granted the other party an exclusive, time-limited right of first negotiation to obtain a license to any anti-fungal product (other than Licensed Product, Subcutaneous Product and Other Products) that such party proposes to out-license in the other party’s territory. However, in the event of the acquisition of a party by a third party, this right of first negotiation will not apply to any such anti‑fungal product of the acquiring third party prior to consummation of the acquisition of such party, acquired by such acquiring third party from another third party after consummation of the acquisition of such party, or developed internally by the acquiring third party, either before or after consummation of the acquisition of such party, without the use of, reliance upon or reference to any technology of the acquired party that is licensed to the other party under the Mundipharma Collaboration Agreement, any technology of the other party that is licensed to the acquired party under the Mundipharma Collaboration Agreement, or any technology jointly developed by the parties pursuant to the Mundipharma Collaboration Agreement. The Company retains the exclusive right to develop, register and commercialize the Licensed Product, Subcutaneous Product and Other Products in the Company Territory, and Mundipharma has granted the Company certain licenses under Mundipharma-controlled technology and jointly-developed technology to develop, register and commercialize Licensed Product, Subcutaneous Product and Other Products in the Company Territory and to manufacture such products and rezafungin worldwide. The parties have agreed to share equally (50/50) the costs of Global Development Plan activities, or Global Development Costs, subject to a cap on Mundipharma’s Global Development Cost share of $31.2 million. The Company would receive additional financial support for Global Development Plan activities through a near-term milestone payment by Mundipharma of $11.1 million. Mundipharma is entitled to credit the full amount of this milestone payment toward future royalties payable to the Company, subject to a limit on the amount by which royalty payments to the Company may be reduced in any quarter. If Mundipharma has not fully credited the amount of such milestone payment toward royalties payable to the Company before the earlier of (i) December 31, 2024 and (ii) termination of the Mundipharma Collaboration Agreement by Mundipharma, the Company will be obligated to refund the uncredited portion of such milestone payment to Mundipharma on the earlier of such dates. The total potential transaction value is $568.0 million, including an equity investment, an up-front payment, global development funding, and certain development, regulatory, and commercial milestones. The Company is also eligible for double-digit royalties in the teens on tiers of annual net sales. Either party may terminate the Mundipharma Collaboration Agreement for uncured material breach by the other party. Mundipharma may terminate the Mundipharma Collaboration Agreement at will, provided that if Mundipharma terminates the Mundipharma Collaboration Agreement in its entirety prior to the last visit of the last patient in both the ReSPECT Trial and the ReSTORE Trial, Mundipharma will continue to be liable for its share of Global Development Costs as described above. The Company may terminate the Agreement if Mundipharma or any of its affiliates or sublicensees, directly or indirectly through any third party, commences any interference or opposition proceeding with respect to, challenges the validity or enforceability of, or opposes any extension of or the grant of a supplementary protection certificate with respect to, any of the Company's patent rights licensed to Mundipharma, or upon an insolvency event of Mundipharma. Revenue Recognition The Company determined the transaction price is equal to the up-front fee of $30.0 million plus the research and development funding of $31.2 million. The common stock issued pursuant to the Mundipharma Stock Purchase Agreement was determined to be issued at fair market value after applying a lack of marketability discount as Mundipharma received restricted shares. Therefore, no additional premium or discount was allocated to the transaction price of the Agreement for the share issuance. The transaction price was allocated to the performance obligations on the basis of the relative stand-alone selling price estimated for each performance obligation. In estimating the stand-alone selling price for each performance obligation, the Company developed assumptions that require judgment and included forecasted revenues, expected development timelines, discount rates, probabilities of technical and regulatory success and costs for manufacturing clinical supplies. A description of the distinct performance obligations identified under the Agreement, as well as the amount of revenue allocated to each distinct significant performance obligation, is as follows: Licenses of Intellectual Property. The license to the Company’s intellectual property, bundled with the associated know-how, represents a distinct performance obligation. The license and associated know-how was transferred to Mundipharma during September 2019, therefore the Company recognized the full revenue related to this performance obligation in the amount of $17.9 million in September 2019 as collaboration revenue in its condensed consolidated statements of operations and comprehensive loss. Research and Development Services. The Company and Mundipharma share equally in the costs of ongoing rezafungin clinical development in the Licensed Territory up to the specified cap, which represents a distinct performance obligation. The Company records these cost-sharing payments due from Mundipharma as collaboration revenue. The Company concluded that progress towards completion of the performance obligation related to the research and development services is best measured in an amount proportional to the research and development expenses incurred and the total estimated research and development expenses. Clinical Supply Services. The Company's initial obligation to supply rezafungin for ongoing clinical development in the Licensed Territory represents a distinct performance obligation. The Company concluded that progress towards completion of the performance obligations related to the clinical supply services is best measured in an amount proportional to the clinical supply services expenses incurred and the total estimated clinical supply services. Milestone Payments. The Company determined that as of March 31, 2021, all the potential milestone payments are probable of significant revenue reversal as their achievement is highly dependent on factors outside the Company's control or are otherwise constrained under the variable consideration guidance. Therefore, these payments have been fully constrained and are therefore not included in the transaction price. At the end of each subsequent reporting period, the Company will re-evaluate the probability of achievement of each milestone and any related constraint. In November 2020, the Company achieved a $11.1 million milestone under the Agreement, which is recorded as long-term deferred revenue as of March 31, 2021 because the rights to consideration is not expected to be satisfied within one year. The Company received payment for this milestone in January 2021. Mundipharma is entitled to credit the full amount of this milestone payment toward future royalties payable to the Company, subject to a limit on the amount by which royalty payments to the Company may be reduced in any quarter. If Mundipharma has not fully credited the amount of such milestone payment toward royalties payable to the Company before the earlier of (i) December 31, 2024 and (ii) termination of the Mundipharma Collaboration Agreement by Mundipharma, the Company will be obligated to refund the uncredited portion of such milestone payment to Mundipharma on the earlier of such dates. No revenue related to milestones was recognized during the three months ended March 31, 2021 or 2020. Royalties. As the license is deemed to be the predominant item to which sales-based royalties relate, the Company will recognize revenue when the related sales occur. No royalty revenue was recognized during the three months ended March 31, 2021 or 2020. Janssen Collaboration Agreement On March 31, 2021, the Company entered into an exclusive worldwide license and collaboration agreement, or the Janssen Collaboration Agreement, with Janssen Pharmaceuticals, Inc., or Janssen, one of the Janssen Pharmaceutical Companies of Johnson & Johnson, to develop and commercialize Cloudbreak AVCs for the prevention and treatment of seasonal and pandemic influenza, including CD388. Under the terms of the Janssen Collaboration Agreement, the Company will collaborate in the research, preclinical and early clinical development of CD388, or another mutually-agreed influenza AVC development candidate, under an agreed research plan with the objective of advancing development through Phase 1 clinical trials and the first Phase 2 clinical trial. The Company will be responsible for performing all investigational new drug, or IND, -enabling studies and clinical trials under the research plan. Both parties will be responsible for conducting certain specified chemistry, manufacturing and controls development activities under the research plan. Janssen will be solely responsible, and reimburse the Company for internal personnel and out-of-pocket costs incurred in performing the research plan activities in accordance with an agreed budget. After completion of the research plan and upon its election to proceed with development, Janssen will be solely responsible for late-stage development, manufacturing, registration and commercialization. The total potential transaction value is $780.0 million, including a $27.0 million upfront payment, $58.0 million in budgeted research and development funding, and up to $695.0 million in development, regulatory and commercial milestones. In addition, the Company is entitled to tiered royalties on worldwide sales in the mid to high single digits. The Company also has the option to co-detail the first product under the collaboration to receive marketing approval in the U.S. The effectiveness of the Janssen Collaboration Agreement was subject to the expiration or earlier termination of all applicable waiting periods under the Hart-Scott-Rodino Antitrust Improvements Act, which had not occurred as of March 31, 2021. Accordingly, the Company has neither received any cash nor recognized any revenue associated with this agreement for the three months ended March 31, 2021. On May 12, 2021, the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act for the Janssen Collaboration Agreement expired and the Janssen Collaboration Agreement became effective. Contract Liabilities The following table presents a summary of the activity in the Company's contract liabilities (recorded as deferred revenue on the balance sheet) during the three months ended March 31, 2021 (in thousands): Opening balance, December 31, 2020 $ 25,010 Payments received in advance 5,161 Revenue from performance obligations satisfied during reporting period (2,408) Closing balance, March 31, 2021 $ 27,763 Current portion of deferred revenue $ 15,411 Long-term portion of deferred revenue 12,352 Total deferred revenue, March 31, 2021 $ 27,763 All of the company's revenue for the three months ended March 31, 2021 was earned from work performed under the Mundipharma Collaboration Agreement. The following table presents our contract revenues disaggregated by timing of revenue recognition and excludes royalty revenue (in thousands): Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Point in Time Over Time Point in Time Over Time Revenue from Mundipharma Collaboration Agreement: Research and Development Services $ — $ 2,331 $ — $ 1,992 Clinical Supply Services — 77 — 538 Total revenue from Mundipharma Collaboration Agreement $ — $ 2,408 $ — $ 2,530

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Lease Obligations The following table presents information about the amount, timing and uncertainty of cash flows arising from the Company's operating lease as of March 31, 2021 (in thousands): 2021 748 Total undiscounted operating lease payments $ 748 Less: Imputed interest (32) Present value of lease payments $ 716 The balance sheet classification of the Company's operating lease is as follows (in thousands): Balance Sheet Classification: Operating lease right-of-use asset $ 663 Current lease liability $ 716 As of March 31, 2021, the weighted average remaining lease term was 0.8 years. Cash paid for amounts included in the present value of operating lease liabilities was $0.2 million for the three months ended March 31, 2021. Operating lease costs were $0.2 million for the three months ended March 31, 2021. These costs are primarily related to the Company's long-term operating lease, but also include immaterial amounts for variable leases and short-term leases with terms greater than 30 days. Contractual Obligations The Company enters into contracts in the normal course of business with vendors for research and development activities, manufacturing, and professional services. These contracts generally provide for termination either on notice or after a notice period.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	3 Months Ended
	Mar. 31, 2021
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS Controlled Equity Sales Agreement On April 5, 2021, the Company increased the aggregate offering price of the shares of its common stock that may be sold pursuant to the Sales Agreement from $35.0 million to $70.0 million.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company has a limited operating history and the sales and income potential of the Company’s business and market are unproven. The Company has experienced net losses and negative cash flows from operating activities since its inception. At March 31, 2021, the Company had an accumulated deficit of $353.0 million. The Company expects to continue to incur net losses into the foreseeable future. Successful transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support the Company’s cost structure. At March 31, 2021, the Company had cash, cash equivalents and restricted cash of $48.8 million. Based on the Company’s current business plan, management believes that existing cash and cash equivalents will not be sufficient to fund the Company’s obligations for twelve months from the issuance of these financial statements. The Company’s ability to execute its operating plan depends on its ability to obtain additional funding through equity offerings, debt financings or potential licensing and collaboration arrangements. The accompanying consolidated financial statements have been prepared assuming the Company will continue as a going concern, which contemplates the realization of assets and settlement of liabilities in the normal course of business. However, the Company’s current working capital, anticipated operating expenses and net losses and the uncertainties surrounding its ability to raise additional capital as needed, as discussed below, raise substantial doubt about its ability to continue as a going concern for a period of one year following the date that these financial statements are issued. The consolidated financial statements do not include any adjustments for the recovery and classification of assets or the amounts and classification of liabilities that might be necessary should the Company be unable to continue as a going concern. The Company plans to continue to fund its losses from operations through cash and cash equivalents on hand, as well as through future equity offerings, debt financings, other third party funding, and potential licensing or collaboration arrangements. There can be no assurance that additional funds will be available when needed from any source or, if available, will be available on terms that are acceptable to the Company. Even if the Company raises additional capital, it may also be required to modify, delay or abandon some of its plans which could have a material adverse effect on the Company’s business, operating results and financial condition and the Company’s ability to achieve its intended business objectives. Any of these actions could materially harm the Company’s business, results of operations and future prospects. In addition to the foregoing, the Company is monitoring closely the impact of the COVID-19 pandemic on its business and has taken steps designed to protect the health and safety of its employees while continuing its operations. Given the level of uncertainty regarding the duration and impact of the COVID-19 pandemic on capital markets and the U.S. economy, the Company is currently unable to assess the impact of the COVID-19 pandemic on its future access to capital. The Company is continuing to monitor the spread of COVID-19 and its potential impact on the Company's operations. The full extent to which the COVID-19 pandemic will impact the Company's business, results of operations, financial condition, clinical trials, and preclinical research will depend on future developments that are highly uncertain, including actions taken to contain or treat COVID-19 and their effectiveness, as well as the economic impact on national and international markets.
Unaudited Interim Financial Data	Unaudited Interim Financial Data The accompanying condensed consolidated financial statements are unaudited and have been prepared by the Company in accordance with U.S. generally accepted accounting principles, or GAAP, as found in the Accounting Standards Codification, or ASC, of the Financial Accounting Standards Board, or FASB. Certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. These interim condensed consolidated financial statements, in the opinion of management, reflect all normal recurring adjustments necessary for a fair presentation of the Company’s financial position and results of operations for the interim periods ended March 31, 2021 and 2020.
Basis of Consolidation	Basis of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of expenses during the reporting period. The Company evaluates its estimates and assumptions on an ongoing basis. The most significant estimates in the Company’s consolidated financial statements relate to estimating the fair value of the Company’s stock options, estimated collaboration expenses and incurred expenses related to the Mundipharma Collaboration Agreement (as defined below), and certain accruals, including those related to nonclinical and clinical activities. Although the estimates are based on the Company’s knowledge of current events, comparable companies, and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions.
Segment Information	Segment Information Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, the Chief Executive Officer, in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business as one operating segment.
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash The Company considers all short-term investments purchased with a maturity of three months or less when acquired to be cash equivalents. Restricted cash represents cash that the Company is required to maintain on hand in order to maintain compliance with an operating covenant in the Third Amendment to the Company's Loan Agreement with Pacific Western Bank. See Note 4 for additional information.
Accounts Receivable	Accounts Receivable Accounts receivable are recorded at their net invoice value and are not interest bearing. The Company reserves specific receivables when collectibility is no longer probable. These reserves are re-evaluated on a regular basis and are adjusted, as needed. Once a receivable is deemed to be uncollectible, such balance is recorded as an allowance for credit losses. No such allowance existed at March 31, 2021 or December 31, 2021.
Property and Equipment	Property and Equipment The Company records property and equipment at cost, which consists of lab equipment, computer equipment and software, office equipment, furniture and fixtures and leasehold improvements. Property and equipment is depreciated using the straight-line method over the estimated useful lives (generally three
Income Taxes	Income Taxes The Company follows ASC 740, Income Taxes , or ASC 740, in reporting deferred income taxes. ASC 740 requires a company to recognize deferred tax assets and liabilities for expected future income tax consequences of events that have been recognized in the Company’s consolidated financial statements. Under this method, deferred tax assets and liabilities are determined based on temporary differences between financial statement carrying amounts and the tax basis of assets and liabilities using enacted tax rates in the years in which the temporary differences are expected to reverse. Valuation allowances are provided if, based on the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. The Company accounts for uncertain tax positions pursuant to ASC 740, which prescribes a recognition threshold and measurement process for financial statement recognition of uncertain tax positions taken or expected to be taken in a tax return. If the tax position meets this threshold, the benefit to be recognized is measured as the tax benefit having the highest likelihood of being realized upon ultimate settlement with the taxing authority. The Company recognizes interest accrued related to unrecognized tax benefits and penalties in the provision for income taxes.
Revenue Recognition	Revenue Recognition The Company recognizes revenue is accordance with ASC Topic 606, Revenue from Contracts with Customers , or Topic 606, which applies to all contracts with customers, except for contracts that are within the scope of other standards, such as leases, insurance, collaboration arrangements and financial instruments. Under Topic 606, an entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration that the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Topic 606, the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations, and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. In a contract with multiple performance obligations, the Company must develop estimates and assumptions that require judgment to determine the underlying stand-alone selling price for each performance obligation, which determines how the transaction price is allocated among the performance obligations. The estimation of the stand-alone selling price(s) may include estimates regarding forecasted revenues or costs, development timelines, discount rates, and probabilities of technical and regulatory success. The Company evaluates each performance obligation to determine if it can be satisfied at a point in time or over time. Any change made to estimated progress towards completion of a performance obligation and, therefore, revenue recognized will be recorded as a change in estimate. In addition, variable consideration must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price. If a license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in a contract, the Company recognizes revenues from the transaction price allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from the allocated transaction price. The Company evaluates the measure of progress at each reporting period and, if necessary, adjusts the measure of performance and related revenue or expense recognition as a change in estimate. At the inception of each arrangement that includes milestone payments, the Company evaluates whether the milestones are considered probable of being reached. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s or a collaboration partner’s control, such as regulatory approvals, are generally not considered probable of being achieved until those approvals are received. At the end of each reporting period, the Company re-evaluates the probability of achievement of milestones that are within its or a collaboration partner’s control, such as operational developmental milestones and any related constraint, and, if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which will affect collaboration revenues and earnings in the period of adjustment. Revisions to the Company’s estimate of the transaction price may also result in negative collaboration revenues and earnings in the period of adjustment. For arrangements that include sales-based royalties, including commercial milestone payments based on the level of sales, and a license is deemed to be the predominant item to which the royalties relate, the Company will recognize revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied, or partially satisfied. To date, the Company has not recognized any royalty revenue from collaborative arrangements. In September 2019, the Company entered into a Collaboration and License Agreement, or the Mundipharma Collaboration Agreement, with Mundipharma Medical Company, or Mundipharma. The Company concluded that there were three significant performance obligations under the Mundipharma Collaboration Agreement: the license, the research and development services, and the clinical supply services, and that the obligations are distinct from each other. Revenue associated with the license was recognized upon delivery in September 2019. The Company concluded that progress towards completion of the research and development and clinical supply performance obligations related to the Mundipharma Collaboration Agreement is best measured in an amount proportional to the collaboration expenses incurred and the total estimated collaboration expenses. The Company periodically reviews and updates the estimated collaboration expenses, when appropriate, which may adjust revenue recognized for the period. While such changes to the Company’s estimates have no impact on the Company’s reported cash flows, the amount of revenue recorded in the period could be materially impacted. The transaction price to be recognized as revenue under the Mundipharma Collaboration Agreement consists of the upfront payment and estimated reimbursable research and development and clinical supply costs. Potential future payments for variable consideration, such as clinical, regulatory or commercial milestones, will be recognized when it is probable that, if recorded, a significant reversal will not take place. Potential future royalty payments will be recorded as revenue when the associated sales occur. See Note 7 for additional information.
Research and Development Costs	Research and Development Costs Research and development expenses consist of wages, benefits and stock-based compensation charges for research and development employees, scientific consultant fees, facilities and overhead expenses, laboratory supplies, manufacturing expenses, and nonclinical and clinical trial costs. The Company accrues nonclinical and clinical trial expenses based on work performed, which relies on estimates of total costs incurred based on patient enrollment, completion of studies, and other events. Costs incurred in purchasing technology assets and intellectual property are charged to research and development expense if the technology has not been conclusively proven to be feasible and has no alternative future use.
Preclinical and Clinical Trial Accruals	Preclinical and Clinical Trial Accruals The Company makes estimates of its accrued expenses as of each balance sheet date in the financial statements based on the facts and circumstances known at that time. Accrued expenses for preclinical studies and clinical trials are based on estimates of costs incurred and fees that may be associated with services provided by contract research organizations, or CROs, clinical trial investigational sites and other clinical trial-related activities. Payments under certain contracts with such parties depend on factors such as successful enrollment of patients, site initiation and the completion of clinical trial milestones. In accruing for these services, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If possible, the Company obtains information regarding unbilled services directly from these service providers. However, the Company may be required to estimate these services based on other available information. If the Company underestimates or overestimates the activities or fees associated with a study or service at a given point in time, adjustments to research and development expenses may be necessary in future periods. Historically, estimated accrued liabilities have approximated actual expense incurred. Subsequent changes in estimates may result in a material change in accruals.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for stock-based compensation expense related to stock options, Restricted Stock Units, or RSUs, Performance-based RSUs, or PRSUs, and Employee Stock Purchase Plan rights by estimating the fair value on the date of grant using the Black-Scholes option pricing model. For awards subject to time-based vesting conditions, including those with a graded vesting schedule, stock-based compensation expense is recognized using the straight-line method. For performance-based awards to employees, (i) the fair value of the award is determined on the grant date, (ii) the Company assesses the probability of the individual performance milestones under the award being achieved and (iii) the fair value of the shares subject to the milestone is expensed over the implicit service period commencing once
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing the net loss allocable to common shares by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss allocable to common shares by the weighted-average number of common shares and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. Dilutive common stock equivalents are comprised of warrants, Series X Convertible Preferred Stock, as well as RSUs, PRSUs and options outstanding under the Company’s stock option plans. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company follows ASC 820-10 issued by the FASB with respect to fair value reporting for financial assets and liabilities. The guidance defines fair value, provides guidance for measuring fair value and requires certain disclosures. The guidance does not apply to measurements related to share-based payments. The guidance discusses valuation techniques such as the market approach (comparable market prices), the income approach (present value of future income or cash flow), and the cost approach (cost to replace the service capacity of an asset or replacement cost). The guidance establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. The Company’s financial instruments consist of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, accrued liabilities, and a term loan. Fair value estimates of these instruments are made at each reporting period end based on relevant market information. These estimates may be subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. The carrying amount of cash and cash equivalents, restricted cash, accounts receivable, accounts payable, and accrued liabilities are generally considered to be representative of their respective fair values because of the short-term nature of those instruments. The Company believes that the fair value of long-term debt approximates its carrying value.
Recently Issued Accounting Standards	Recently Issued Accounting Standards Recently Issued Accounting Standards Not Yet Adopted In August 2020, the FASB issued ASU 2020-06, "Accounting for Convertible Instruments and Contracts in an Entity's Own Equity," simplifies the accounting for certain convertible instruments by removing the separation models for convertible debt with a cash conversion feature or convertible instruments with a beneficial conversion feature. As a result, more convertible debt instruments will be reported as a single liability instrument with no separate accounting for embedded conversion features. Additionally, this ASU amends the diluted EPS calculation for convertible instruments by requiring the use of the if-converted method. The treasury stock method is no longer available. Entities may adopt this ASU using either a full or modified retrospective approach, and it is effective for interim and annual reporting periods beginning after December 15, 2021. Early adoption is permitted for interim and annual reporting periods beginning after December 15, 2020. The Company is assessing the impact the adoption of this ASU will have on its financial statements. Recently Adopted Accounting Standards In December 2019, the FASB issued ASU 2019-12, "Simplifying the Accounting for Income Taxes," which eliminates certain exceptions within ASC 740, Income Taxes, and clarifies other aspects of the current guidance to promote consistency among reporting entities. The Company adopted ASU 2019-12 effective January 1, 2021. The adoption of this standard did not have a material impact on the Company's financial statements.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Summary of Outstanding Potentially Dilutive Securities Excluded from Calculation of Diluted Net Income (Loss) Per Share	The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because doing so would be anti-dilutive (in common stock equivalent shares): Three Months Ended 2021 2020 Common stock warrants 12,517,328 12,517,328 Series X Convertible Preferred stock 10,442,780 10,965,190 Common stock options, RSUs and PRSUs issued and outstanding 8,648,708 6,658,011 Total 31,608,816 30,140,529

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Summary of Financial Instruments Measured at Fair Value on a Recurring Basis	The following tables summarize the Company’s financial instruments measured at fair value on a recurring basis (in thousands): TOTAL LEVEL 1 LEVEL 2 LEVEL 3 March 31, 2021 Assets: Cash and money market funds $ 42,863 $ 42,863 $ — $ — Restricted cash and money market accounts 5,926 5,926 — — Total assets at fair value $ 48,789 $ 48,789 $ — $ — December 31, 2020 Assets: Cash and money market accounts $ 35,912 $ 35,912 $ — $ — Restricted cash and money market accounts 7,037 7,037 — — Total assets at fair value $ 42,949 $ 42,949 $ — $ —

DEBT (Tables)

DEBT (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Schedule of Future Principal Payments	As of March 31, 2021, future principal payments due under the Third Amendment of the Term A Loan are as follows (in thousands): Year ended: December 31, 2021 $ 3,333 December 31, 2022 2,593 Total future principal payments due under the Term A Loan $ 5,926

STOCKHOLDERS_ EQUITY (Tables)

STOCKHOLDERS’ EQUITY (Tables)	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Schedule of Common Stock Reserved for Future Issuance	Common stock reserved for future issuance is as follows (in common stock equivalent shares): March 31, December 31, Common stock warrants 12,517,328 12,517,328 Series X Convertible Preferred Stock 10,442,780 10,442,780 Common stock options, RSUs and PRSUs issued and outstanding 8,648,708 6,787,033 Authorized for future stock awards under the Company's option plans 2,642,065 2,813,131 Authorized for future issuance under the ESPP 969,899 521,986 Total 35,220,780 33,082,258

EQUITY INCENTIVE PLANS (Tables)

EQUITY INCENTIVE PLANS (Tables)	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Summary of Restricted Stock Units and Performance-based Restricted Stock Units Activity	The following table summarizes RSU and PRSU activity during the three months ended March 31, 2021: Number of Weighted Average Grant Date Fair Value Outstanding at December 31, 2020 428,235 $ 3.55 RSUs and PRSUs granted 125,925 2.56 RSUs and PRSUs vested (100,558) 3.41 RSUs and PRSUs canceled (2,125) 2.27 Outstanding at March 31, 2021 451,477 $ 3.31
Summary of Stock Option Activity	The following table summarizes stock option activity during the three months ended March 31, 2021: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life in Years Total Aggregate Intrinsic Value (in thousands) Outstanding at December 31, 2020 6,358,798 $ 3.59 7.04 $ 55 Options granted 1,894,850 2.55 Options exercised (486) 1.98 Options canceled (55,931) 4.34 Outstanding at March 31, 2021 8,197,231 $ 3.35 7.56 $ 1,826 Vested and expected to vest at March 31, 2021 8,197,231 $ 3.35 7.56 $ 1,826 Exercisable at March 31, 2021 4,401,525 $ 4.10 6.21 $ 806
Schedule of Stock-based Compensation Expense	Stock-based compensation expense recognized for restricted shares, RSUs, PRSUs, stock options, and the ESPP has been reported in the statements of operations as follows (in thousands): Three Months Ended 2021 2020 Research and development $ 391 $ 601 General and administrative 488 645 Total $ 879 $ 1,246

SIGNIFICANT AGREEMENTS AND CO_2

SIGNIFICANT AGREEMENTS AND CONTRACTS (Tables)	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Collaborative Agreement Liabilities and Revenues Disaggregated by Timing of Revenue Recognition	The following table presents a summary of the activity in the Company's contract liabilities (recorded as deferred revenue on the balance sheet) during the three months ended March 31, 2021 (in thousands): Opening balance, December 31, 2020 $ 25,010 Payments received in advance 5,161 Revenue from performance obligations satisfied during reporting period (2,408) Closing balance, March 31, 2021 $ 27,763 Current portion of deferred revenue $ 15,411 Long-term portion of deferred revenue 12,352 Total deferred revenue, March 31, 2021 $ 27,763 The following table presents our contract revenues disaggregated by timing of revenue recognition and excludes royalty revenue (in thousands): Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Point in Time Over Time Point in Time Over Time Revenue from Mundipharma Collaboration Agreement: Research and Development Services $ — $ 2,331 $ — $ 1,992 Clinical Supply Services — 77 — 538 Total revenue from Mundipharma Collaboration Agreement $ — $ 2,408 $ — $ 2,530

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Schedule of Amount, Timing and Uncertainty of Cash Flows from Operating Lease	The following table presents information about the amount, timing and uncertainty of cash flows arising from the Company's operating lease as of March 31, 2021 (in thousands): 2021 748 Total undiscounted operating lease payments $ 748 Less: Imputed interest (32) Present value of lease payments $ 716
Supplemental Balance Sheet Information	The balance sheet classification of the Company's operating lease is as follows (in thousands): Balance Sheet Classification: Operating lease right-of-use asset $ 663 Current lease liability $ 716

THE COMPANY AND BASIS OF PRES_2

THE COMPANY AND BASIS OF PRESENTATION (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)segment	Dec. 31, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ 352,992	$ 334,700
Cash, cash equivalents, and restricted cash at end of period	$ 48,789	$ 42,949	$ 74,314	$ 60,268
Number of operating segments | segment	1

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details)	3 Months Ended
	Mar. 31, 2021
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Useful life	3 years
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Useful life	7 years

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Outstanding Potentially Dilutive Securities Excluded from Calculation of Diluted Net Income (Loss) Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share (in shares)	31,608,816	30,140,529
Common stock warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share (in shares)	12,517,328	12,517,328
Series X Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share (in shares)	10,442,780	10,965,190
Common stock options, RSUs and PRSUs issued and outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share (in shares)	8,648,708	6,658,011

FAIR VALUE MEASUREMENTS - Summa

FAIR VALUE MEASUREMENTS - Summary of Financial Instruments Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets:
Cash and money market funds	$ 42,863	$ 35,912
Restricted cash and money market accounts	5,926	7,037
Total assets at fair value	48,789	42,949
LEVEL 1
Assets:
Cash and money market funds	42,863	35,912
Restricted cash and money market accounts	5,926	7,037
Total assets at fair value	48,789	42,949
LEVEL 2
Assets:
Cash and money market funds	0	0
Restricted cash and money market accounts	0	0
Total assets at fair value	0	0
LEVEL 3
Assets:
Cash and money market funds	0	0
Restricted cash and money market accounts	0	0
Total assets at fair value	$ 0	$ 0

DEBT - Additional Information (

DEBT - Additional Information (Details) - Term Loan - USD ($)	Mar. 31, 2021	Oct. 03, 2016
Loan Agreement
Debt Instrument [Line Items]
Variable annual rate	4.50%
Term A Loan
Debt Instrument [Line Items]
Borrowed from the lender		$ 10,000,000

DEBT - Schedule of Future Princ

DEBT - Schedule of Future Principal Payments (Details) - Term A Loan - Term Loan $ in Thousands	Mar. 31, 2021USD ($)
Year ended:
December 31, 2021	$ 3,333
December 31, 2022	2,593
Total future principal payments due under the Term A Loan	$ 5,926

STOCKHOLDERS_ EQUITY - 2020 Rig

STOCKHOLDERS’ EQUITY - 2020 Rights Offering (Details) - USD ($) $ / shares in Units, $ in Thousands	Feb. 12, 2020	Jan. 22, 2020	Mar. 31, 2020
Class of Stock [Line Items]
Recognition of beneficial conversion feature			$ 0
Rights Offering, February 2020
Class of Stock [Line Items]
Net proceeds	$ 30,000	$ 30,000
Offering costs	800
Proceeds from right offerings	$ 29,200
Rights Offering, February 2020 | Common Stock
Class of Stock [Line Items]
Shares sold	6,639,307
Offering price (in dollars per share)	$ 2.51
Rights Offering, February 2020 | Series X Convertible Preferred Stock
Class of Stock [Line Items]
Shares sold	531,288
Offering price (in dollars per share)	$ 25.10
Recognition of beneficial conversion feature	$ 2,800

STOCKHOLDERS_ EQUITY - Narrativ

STOCKHOLDERS’ EQUITY - Narrative (Details)	Aug. 12, 2020shares	May 31, 2018$ / sharesshares	Mar. 31, 2021USD ($)voteForEachShare$ / sharesshares	Mar. 31, 2020USD ($)shares	Dec. 31, 2020$ / sharesshares
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)			10,000,000		10,000,000
Preferred stock, par value (in dollars per share) | $ / shares			$ 0.0001		$ 0.0001
Common stock, shares authorized (in shares)			200,000,000		200,000,000
Number of votes for each share held | voteForEachShare			1
Dividends in arrears or default | $			$ 0
Issuance of common stock | $			$ 8,589,000	$ 19,000
Total (in shares)			35,220,780		33,082,258
Common Stock
Class of Stock [Line Items]
Issuance of common stock upon conversion of Series X Convertible Preferred Stock (in shares)	522,410
Issuance of common stock (in shares)			3,327,706	7,600
Issuance of common stock | $			$ 1,000
Series X Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)		5,000,000	5,000,000		5,000,000
Preferred stock, par value (in dollars per share) | $ / shares		$ 0.0001	$ 0.0001		$ 0.0001
Issuance of common stock upon conversion of Series X Convertible Preferred Stock (in shares)	52,241
Common stock issued for each preferred stock (in shares)		10
Maximum ownership following conversion		9.99%
Weighted Average
Class of Stock [Line Items]
Exercise price of warrant (in dollars per share) | $ / shares			$ 6.82		$ 6.82
Common stock warrants
Class of Stock [Line Items]
Total (in shares)			12,517,328		12,517,328
Controlled Equity Sales Agreement, Cantor Fitzgerald and Company
Class of Stock [Line Items]
Shares sold			3,327,706	7,600
Net proceeds | $			$ 8,600,000	$ 19,000

STOCKHOLDERS_ EQUITY - Schedule

STOCKHOLDERS’ EQUITY - Schedule of Common Stock Reserved for Future Issuance (Details) - shares	Mar. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Total (in shares)	35,220,780	33,082,258
Common stock warrants
Class of Stock [Line Items]
Total (in shares)	12,517,328	12,517,328
Series X Convertible Preferred Stock
Class of Stock [Line Items]
Total (in shares)	10,442,780	10,442,780
Common stock options, RSUs and PRSUs issued and outstanding
Class of Stock [Line Items]
Total (in shares)	8,648,708	6,787,033
Authorized for future stock awards under the Company's option plans
Class of Stock [Line Items]
Total (in shares)	2,642,065	2,813,131
Authorized for future issuance under the ESPP
Class of Stock [Line Items]
Total (in shares)	969,899	521,986

EQUITY INCENTIVE PLANS - Additi

EQUITY INCENTIVE PLANS - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value of employee stock options granted (in dollars per share)		$ 1.51	$ 1.39
Total unrecognized share-based compensation expense related to unvested stock options		$ 5.6
Weighted-average period to recognize unrecognized compensation cost		2 years 3 months 18 days
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Automatic annual increase in shares authorized for issuance in equity incentive plan	1.00%
Price of stock option as percentage of estimated fair value of shares on date of grant	85.00%
Limit on employee's payroll deductions as a percentage of eligible compensation		15.00%
Issued pursuant to the ESPP (in shares)		0	0
Estimated unrecognized share-based compensation expense		$ 0.1
Weighted-average period to recognize unrecognized compensation cost		6 months
Restricted Stock Units and Performance-based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs and PRSUs granted (in dollars per share)		$ 2.56	$ 4.24
Fair value of RSUs and PRSUs		$ 0.3	$ 0.3
Estimated unrecognized share-based compensation expense		$ 1.5
Maximum | ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Automatic increase in number of shares available for issuance (in shares)	490,336
2015 EIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Automatic annual increase in shares authorized for issuance in equity incentive plan	4.00%
Term for stock options to be granted	10 years
Price of stock option as percentage of estimated fair value of shares on date of grant	100.00%
Voting power threshold	10.00%
2015 EIP | More than 10% of voting power
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price of stock option as percentage of estimated fair value of shares on date of grant	110.00%
2015 EIP | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
2015 EIP | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years

EQUITY INCENTIVE PLANS - Summar

EQUITY INCENTIVE PLANS - Summary of Restricted Stock Units and Performance-based Restricted Stock Units Activity (Details) - Restricted Stock Units and Performance-based Restricted Stock Units - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Number of RSUs and PRSUs
Outstanding, beginning balance (in shares)	428,235
RSUs and PRSUs granted (in shares)	125,925
RSUs and PRSUs vested (in shares)	(100,558)
RSUs and PRSUs canceled (in shares)	(2,125)
Outstanding, ending balance (in shares)	451,477
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share)	$ 3.55
RSUs and PRSUs granted (in dollars per share)	2.56	$ 4.24
RSUs and PRSUs vested (in dollars per share)	3.41
RSUs and PRSUs canceled (in dollars per share)	2.27
Outstanding, end of period (in dollars per share)	$ 3.31

EQUITY INCENTIVE PLANS - Summ_2

EQUITY INCENTIVE PLANS - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Number of Shares
Outstanding, beginning balance (in shares)	6,358,798
Options granted (in shares)	1,894,850
Options exercised (in shares)	(486)
Options canceled (in shares)	(55,931)
Outstanding, ending balance (in shares)	8,197,231	6,358,798
Vested and expected to vest (in shares)	8,197,231
Exercisable (in shares)	4,401,525
Weighted Average Exercise Price
Outstanding, beginning balance (in dollars per share)	$ 3.59
Options granted (in dollars per share)	2.55
Options exercised (in dollars per share)	1.98
Options canceled (in dollars per share)	4.34
Outstanding, ending balance (in dollars per share)	3.35	$ 3.59
Vested and expected to vest (in dollars per share)	3.35
Exercisable (in dollars per share)	$ 4.10
Weighted Average Remaining Contractual Life in Years
Outstanding	7 years 6 months 21 days	7 years 14 days
Vested and expected to vest	7 years 6 months 21 days
Exercisable	6 years 2 months 15 days
Total Aggregate Intrinsic Value (in thousands)
Outstanding	$ 1,826	$ 55
Vested and expected to vest	1,826
Exercisable	$ 806

EQUITY INCENTIVE PLANS - Schedu

EQUITY INCENTIVE PLANS - Schedule of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	$ 879	$ 1,246
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	391	601
General and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total	$ 488	$ 645

SIGNIFICANT AGREEMENTS AND CO_3

SIGNIFICANT AGREEMENTS AND CONTRACTS - Narrative (Details) - USD ($)	Mar. 31, 2021	Sep. 03, 2019	Mar. 31, 2021	Mar. 31, 2020	Nov. 30, 2020	Dec. 31, 2019
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from collaborative agreement			$ 2,408,000	$ 2,530,000
Janssen Pharmaceuticals, Inc. | Affiliated Entity
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, potential transaction value	$ 780,000,000
Janssen Pharmaceuticals, Inc. | Affiliated Entity | Upfront Payment
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, potential transaction value	27,000,000
Janssen Pharmaceuticals, Inc. | Affiliated Entity | R&D Funding
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, potential transaction value	58,000,000
Janssen Pharmaceuticals, Inc. | Affiliated Entity | Development, Regulatory, and Commercial Milestones
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, potential transaction value	695,000,000
Mundipharma Medical Company | Affiliated Entity
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative agreement, maximum cost share		$ 31,200,000
Payments related to collaborative agreement		30,000,000
Revenue recognized from collaborative agreement related to performance obligation satisfied at a point in time	$ 0		0	0
Collaborative agreement, potential transaction value		568,000,000
Mundipharma Medical Company | Affiliated Entity | License of Intellectual Property
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue recognized from collaborative agreement related to performance obligation satisfied at a point in time						$ 17,900,000
Long-term portion of deferred revenue					$ 11,100,000
Mundipharma Medical Company | Affiliated Entity | Milestone Achievement
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from collaborative agreement			0	0
Mundipharma Medical Company | Affiliated Entity | Royalty
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from collaborative agreement			$ 0	$ 0
Mundipharma Medical Company | Affiliated Entity | Near Term Milestone
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaborative arrangement, additional third party funding commitment		$ 11,100,000

SIGNIFICANT AGREEMENTS AND CO_4

SIGNIFICANT AGREEMENTS AND CONTRACTS - Summary of Contract Liability Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Revenue From Collaborative Arrangement, Excluding Revenue From Contract With Customer, Liability [Roll Forward]
Opening balance, December 31, 2020	$ 13,865
Closing balance, March 31, 2021	15,411
Current portion of deferred revenue	13,865	$ 15,411	$ 13,865
Long-term portion of deferred revenue		12,352	11,145
Total deferred revenue		27,763
Affiliated Entity | Mundipharma Medical Company
Revenue From Collaborative Arrangement, Excluding Revenue From Contract With Customer, Liability [Roll Forward]
Opening balance, December 31, 2020	25,010
Payments received in advance	5,161
Revenue from performance obligations satisfied during reporting period	(2,408)
Closing balance, March 31, 2021	27,763
Current portion of deferred revenue	$ 27,763	$ 27,763	$ 25,010

SIGNIFICANT AGREEMENTS AND CO_5

SIGNIFICANT AGREEMENTS AND CONTRACTS - Revenues Disaggregated by Timing of Revenue Recognition (Details) - Affiliated Entity - Mundipharma Medical Company - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from Mundipharma Collaboration Agreement, Point in Time	$ 0	$ 0
Revenue from Mundipharma Collaboration Agreement, Over Time	2,408	2,530
Research and Development Services
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from Mundipharma Collaboration Agreement, Point in Time	0	0
Revenue from Mundipharma Collaboration Agreement, Over Time	2,331	1,992
Clinical Supply Services
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenue from Mundipharma Collaboration Agreement, Point in Time	0	0
Revenue from Mundipharma Collaboration Agreement, Over Time	$ 77	$ 538

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Amount, Timing and Uncertainty of Cash Flows from Operating Lease (Details) $ in Thousands	Mar. 31, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
2021	$ 748
Total undiscounted operating lease payments	748
Less: Imputed interest	(32)
Present value of lease payments	$ 716

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Operating lease right-of-use asset	$ 663	$ 868
Current lease liability	$ 716	$ 939

COMMITMENTS AND CONTINGENCIES_3

COMMITMENTS AND CONTINGENCIES - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
Weighted average remaining lease term	9 months 18 days
Lease payments	$ 0.2
Lease cost	$ 0.2
Variable lease and short-term lease term included within operating lease cost (greater than)	30 days

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Millions	Apr. 05, 2021	Apr. 04, 2021
Subsequent Event | Controlled Equity Sales Agreement, Cantor Fitzgerald and Company
Subsequent Event [Line Items]
Aggregate offering price	$ 70	$ 35