scPharmaceuticals (SCPH) 10-Q 10 May 23 2023 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2023	May 09, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Trading Symbol	SCPH
Entity Registrant Name	SCPHARMACEUTICALS INC.
Entity Central Index Key	0001604950
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common stock, par value $0.0001 per share
Security Exchange Name	NASDAQ
Entity File Number	001-38293
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-5184075
Entity Address, Address Line One	2400 District Avenue
Entity Address, Address Line Two	Suite 310
Entity Address, City or Town	Burlington
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01803
City Area Code	617
Local Phone Number	517-0730
Document Quarterly Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		35,769,073

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets
Cash and cash equivalents	$ 75,453	$ 71,061
Short-term investments	40,618	47,125
Restricted cash		182
Accounts receivable	3,004
Inventory	3,621	1,230
Prepaid expenses	2,685	2,282
Deposits and other current assets	1,286	1,428
Total current assets	126,667	123,308
Property and equipment, net	48	54
Right-of-use lease assets - operating, net	466	566
Deposits and other assets	190	267
Total assets	127,371	124,195
Current liabilities
Accounts payable	1,626	1,518
Accrued expenses	5,561	5,289
Lease obligation - operating, short-term	419	567
Other current liabilities	129	42
Total current liabilities	7,735	7,416
Term loan, long-term	37,252	36,794
Derivative liability	6,510	7,517
Lease obligation - operating, long-term	5	7
Other liabilities	62	28
Total liabilities	51,564	51,762
Commitments and contingencies (Note 12)
Stockholders’ equity
Preferred stock, $0.0001 par value; 10,000,000 shares authorized and no shares issued and outstanding
Common stock, $0.0001 par value; 150,000,000 shares authorized as of March 31, 2023; 34,257,916 and 35,769,073 shares issued and outstanding as of December 31, 2022 and March 31, 2023, respectively	4	3
Additional paid-in capital	313,541	298,934
Accumulated deficit	(237,746)	(226,536)
Accumulated other comprehensive income	8	32
Total stockholders’ equity	75,807	72,433
Total liabilities and stockholders’ equity	$ 127,371	$ 124,195

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	35,769,073	34,257,916
Common stock, shares outstanding	35,769,073	34,257,916

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Statement [Abstract]
Product revenues, net	$ 2,063
Revenue from Contract with Customer, Product and Service [Extensible Enumeration]	us-gaap:ProductMember
Operating expenses:
Cost of product revenues	$ 605
Research and development	2,116	$ 4,347
Selling, general and administrative	10,896	2,893
Total operating expenses	13,617	7,240
Loss from operations	(11,554)	(7,240)
Other income	990	14
Interest income	1,315	13
Interest expense	(1,961)	(518)
Net loss	$ (11,210)	$ (7,731)
Net loss per share - basic	$ (0.30)	$ (0.28)
Net loss per share - diluted	$ (0.30)	$ (0.28)
Weighted average common shares outstanding - basic	37,800,960	27,368,354
Weighted average common shares outstanding - diluted	37,800,960	27,368,354
Other comprehensive loss:
Unrealized loss on short-term investments	$ (24)	$ (3)
Comprehensive loss	$ (11,234)	$ (7,734)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2021	$ 56,470	$ 3	$ 246,166	$ (189,698)	$ (1)
Beginning Balance, Shares at Dec. 31, 2021		27,366,707
Net loss	(7,731)			(7,731)
Issuance of common stock upon exercise of stock options	21		21
Issuance of common stock upon exercise of stock options, Shares		4,781
Stock-based compensation	636		636
Unrealized loss on short-term investments	(3)				(3)
Ending Balance at Mar. 31, 2022	49,393	$ 3	246,823	(197,429)	(4)
Ending Balance, Shares at Mar. 31, 2022		27,371,488
Beginning Balance at Dec. 31, 2022	72,433	$ 3	298,934	(226,536)	32
Beginning Balance, Shares at Dec. 31, 2022		34,257,916
Net loss	(11,210)			(11,210)
Issuance of common stock under at-the-market offering, net of issuance costs	13,628	$ 1	13,627
Issuance of common stock under at-the-market offering, net of issuance costs, Shares		1,511,157
Stock-based compensation	980		980
Unrealized loss on short-term investments	(24)				(24)
Ending Balance at Mar. 31, 2023	$ 75,807	$ 4	$ 313,541	$ (237,746)	$ 8
Ending Balance, Shares at Mar. 31, 2023		35,769,073

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities
Net loss	$ (11,210,000)	$ (7,731,000)
Adjustments to reconcile net loss to cash used in operating activities
Depreciation expense	6,000	9,000
Amortization expense - right-of-use leased assets - operating	99,000	93,000
Accretion on short-term investments	(517,000)	4,000
Stock-based compensation	980,000	636,000
Non-cash interest expense	493,000	114,000
Fair value adjustment to derivative liability	(1,007,000)
Changes in operating assets and liabilities
Accounts receivable	(3,004,000)
Inventory	(2,390,000)
Prepaid expenses and other assets	(261,000)	187,000
Accounts payable, accrued expenses and other liabilities	317,000	(681,000)
Net cash used in operating activities	(16,494,000)	(7,369,000)
Cash flows from investing activities
Purchases of property and equipment		(6,000)
Maturities of short-term investments	7,000,000
Purchases of short-term investments		(12,784,000)
Net cash (used in) provided by investing activities	7,000,000	(12,790,000)
Cash flows from financing activities
Proceeds from at-the-market offering, net	13,704,000
Principal payments on term loan		(2,500,000)
Proceeds from the exercise of vested stock options		21,000
Net cash (used in) provided by financing activities	13,704,000	(2,479,000)
Net (decrease) increase in cash, cash equivalents and restricted cash	4,210,000	(22,638,000)
Cash, cash equivalents and restricted cash at beginning of period	71,243,000	74,450,000
Cash, cash equivalents and restricted cash at end of period	75,453,000	51,812,000
Supplemental cash flow information
Interest paid	1,485,000	425,000
Taxes paid	69,000	$ 36,000
Supplemental disclosure of non-cash activities
Transfer of issuance costs from other noncurrent assets to equity	$ 76,000

Description of Business and Bas

Description of Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	1. Description of Business and Basis of Presentation Description of Business scPharmaceuticals LLC was formed as a limited liability company under the laws of the State of Delaware on February 19, 2013. On March 24, 2014, scPharmaceuticals LLC was converted to a Delaware corporation and changed its name to scPharmaceuticals Inc. (“the Company”). The Company is a pharmaceutical company focused on developing and commercializing products that have the potential to optimize the delivery of infused therapies, advance patient care and reduce healthcare costs. The Company’s strategy is designed to enable the subcutaneous administration of therapies that have previously been limited to intravenous (“IV”) delivery. The Company’s headquarters and primary place of business is Burlington, Massachusetts. Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and have been prepared on a basis which assumes that the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. The condensed consolidated financial statements reflect the operations of the Company and its wholly-owned subsidiary, scPharmaceuticals Securities Corporation. Certain information and disclosures normally included in financial statements in accordance with U.S. GAAP have been condensed or omitted. Accordingly, these condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements and related notes for the year ended December 31, 2022 included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (the “SEC”) on March 22, 2023. The Company has determined that it operates in one segment. The accompanying condensed consolidated balance sheet as of March 31, 2023, the condensed consolidated statements of operations and comprehensive loss and stockholders’ equity for the three months ended March 31, 2022 and 2023 and condensed consolidated statements of cash flows for the three months ended March 31, 2022 and 2023 are unaudited. The unaudited condensed consolidated financial statements have been prepared on a basis consistent with that used to prepare the Company’s audited annual financial statements and include, in the opinion of management, adjustments, consisting of normal recurring items, necessary for the fair statement of the condensed consolidated financial statements. The operating results for the three months ended March 31, 2023 are not necessarily indicative of the results expected for the full year ending December 31, 2023. Liquidity As of March 31, 2023, the Company had an accumulated deficit of approximately $ 237.7 million. Management expects to continue to incur operating losses for the foreseeable future. The Company has financed its operations to date from proceeds from the sale of common stock, preferred stock and the incurrence of debt. As of March 31, 2023 , the Company had cash, cash equivalents, and short-term investments of $ 116.1 million. On October 13, 2022 (the “Closing Date”), the Company entered into a Credit Agreement and Guaranty (the "Oaktree Agreement") with, among others, the lenders from time to time party thereto (the "Lenders") and Oaktree Fund Administration, LLC, in its capacity as administrative agent for the Lenders (Note 9). The Company's existing cash, cash equivalents and short-term investments, including the available proceeds from the first tranche of the Oaktree Agreement, will be sufficient to meet its cash commitments for at least the next 12 months after the date that the interim condensed consolidated financial statements are issued. Additionally, the Company expects to have access to funds pursuant to an at-the-market offering program with Cowen and Company, LLC (Note 10), or could otherwise seek additional funding through a combination of public or private equity offerings if it believes additional resources are needed. Additional financing may not be available on a timely basis on terms acceptable to the Company, or at all.

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Significant Accounting Policies	2. Significant Accounting Policies Use of Estimates The preparation of financial statements in conformity with U.S. 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 reported periods. Actual results could differ from those estimates. Cash, Cash Equivalents and Restricted Cash Cash, cash equivalents and restricted cash consists of bank deposits and money market accounts with financial institutions. Cash equivalents are carried at cost which approximates fair value due to their short-term nature and which the Company believes do not have a material exposure to credit risk. The Company considers all highly liquid investments with maturities of three months or less from the date of purchase to be cash equivalents. The Company’s cash and cash equivalent accounts, at times, may exceed federally insured limits. The Company has not experienced any losses in such accounts. Cash, cash equivalents and restricted cash consists of the following (in thousands): December 31, March 31, Cash and cash equivalents $ 71,061 $ 75,453 Restricted cash 182 - Cash, cash equivalents and restricted cash $ 71,243 $ 75,453 Accounts Receivable Accounts receivable are recorded net of any estimated expected credit losses. The Company's measurement of expected credit losses is based on relevant information about past events, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. To date, expected credit losses have not been material. Concentration of Credit Risk Financial instruments that subject the Company to credit risk primarily consist of cash and cash equivalents and short-term investments. The Company maintains its cash and cash equivalent balances with high-quality financial institutions and, consequently, the Company believes that such funds are subject to minimal credit risk. The Company’s short-term investments consist of United States Treasury securities, commercial paper and United States Government Agency securities. The Company has adopted an investment policy that limits the amounts the Company may invest in any one type of investment and requires all investments held by the Company to hold a minimum rating, thereby reducing credit risk exposure . As the Company executes its commercial launch, the Company has a limited number of specialty pharmacy customers. As of, and for the quarter ended, March 31, 2023, one customer represents 92 % of accounts receivable and revenue, respectively. Investments The Company invests excess cash balances in available-for-sale debt securities. The Company determines the appropriate classification of these securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. The Company reports available-for-sale investments at fair value at each balance sheet date and includes any unrealized gains and losses in accumulated other comprehensive income (loss), a component of stockholders’ equity. Realized gains and losses are determined using the specific identification method and are included in other income (expense). If any adjustment to fair value reflects a decline in the value of the investment, the Company considers all available evidence to evaluate the extent to which the decline is “other than temporary,” including the intention to sell and, if so, marks the investment to market through a charge to the Company’s consolidated statements of operations and comprehensive loss . Inventory Inventory is stated at the lower of cost and net realizable value and consists of raw materials, work-in-process and finished goods. The Company began capitalizing inventory costs following U.S. Food and Drug Administration ("FDA") approval of FUROSCIX on October 7, 2022. Inventory is sold on a first in, first out ("FIFO") basis. The Company periodically reviews inventory for expiry and obsolescence and writes it down accordingly, if necessary. Prior to FDA approval of FUROSCIX, the Company expensed all inventory-related costs, including that used for clinical development, to research and development ("R&D") costs in the period incurred. Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in right-of-use (“ROU”) lease assets, current portion of lease obligations, and long-term lease obligations on the Company’s balance sheets. ROU lease assets represent the Company’s right to use an underlying asset for the lease term and lease obligations represent the Company’s obligation to make lease payments arising from the lease. Operating ROU lease assets and obligations are recognized at the commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The ROU lease asset excludes lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term . Debt Issuance Costs Debt issuance costs are amortized to interest expense using the effective interest rate method over the term of the debt. Debt issuance costs paid to the lender and third parties are reflected as a discount to the debt in the consolidated balance sheets . Revenue Recognition The Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangement that the Company determines are within the scope of Accounting Standards Codification ("ASC") Topic 606, Revenue from Contracts with Customer (“Topic 606”), the Company 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 the Company satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that it 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 the performance obligation is satisfied. The Company has identified one performance obligation, the delivery of FUROSCIX to its customers. The Company has not incurred any incremental costs associated with obtaining contracts with customers. The Company’s revenues consist solely of the sale of FUROSCIX to customers in the United States. Product Net Sales FUROSCIX was approved by the FDA on October 7, 2022. The Company launched sales of FUROSCIX in the first quarter of 2023 to specialty pharmacies (“SPs”). The Company recognizes revenue from product sales at a point in time, typically upon receipt of product at the SPs, the date at which the rights, title, interest and risk of loss are transferred. Revenues from product sales are recorded at the net sales price, which includes estimates of variable consideration that result from (a) sales discounts, (b) rebates (c) co-pay assistance, and (d) product returns. Reserves are established for the estimates of variable consideration based on the amounts earned or to be claimed on the related sales. The reserves for variable consideration are reflected as either as a reduction to the related account receivable or as an accrued liability, depending on how the consideration is settled. The amount of variable consideration that is included in the transaction price may be constrained and is included in net product revenues only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. Actual amounts of consideration ultimately received may differ from the Company's estimates. If actual results vary from its estimates, the Company adjusts these estimates, which would affect net product revenue and earnings in the period such variances become known. Sales Discounts : Sales discounts are agreed-upon discounts, from negotiated contracts, taken directly off the Company’s sales invoices. Sales discounts are recorded as an offset to revenue based on contractual terms at the time revenue from the sale is recognized. Rebates : Allowance for rebates include mandated discounts under the Medicaid Drug Rebate Program and the Medicare Part D prescription drug benefit, TRICARE program and contractual rebates with commercial payers. Rebates are amounts owed after the final dispensing of the product to a benefit plan participant and are based upon contractual agreements or statutory requirements. The allowance for rebates is based on contracted or statutory discount rates and expected utilization by benefit plan participants. The Company’s estimates for expected utilization of rebates are based on utilization data received from the SPs since product launch. Rebates are generally invoiced and paid in arrears so that the accrual balance consists of an estimate of the amount expected to be incurred for the current quarter’s activity, plus an accrual balance for prior quarters’ unpaid rebates. If actual future rebates vary from estimates, the Company may need to adjust prior period accruals, which would affect revenue in the period of adjustment. Co-Payment Assistance: The Company offers co-payment assistance to commercially insured patients meeting certain eligibility requirement. Co-payment assistance is accrued at the time of product sale to SPs based on estimated patient participation and average co-pay benefit to be paid per a claim. The Company’s estimated amounts are compared to actual program participation and co-pay amounts paid using data provided by third-party administrators. If actual amounts differ from the original estimates the assumptions being applied are updated and adjustment for prior period accruals will be adjusted in the current period. Product Returns: Consistent with industry practice, the Company offers SPs limited product return rights for damages, shipment errors, and expiring product, provided that the return is within a specified period around the product expiration date as set forth in the applicable individual distribution agreement. The Company does not allow product returns for product that has been dispensed to a patient. As the Company receives inventory reports from the SPs and has the ability to control the amount of product that is sold to the SPs, it is able to make a reasonable estimate of future potential product returns based on this on-hand channel inventory data and sell-through data obtained from the SPs. In arriving at its estimate, the Company also considers historical product returns, the underlying product demand, and industry data specific to the specialty pharmaceutical distribution industry. Research and Development Costs Research and development costs are expensed as incurred. Nonrefundable advance payments, if any, for goods or services used in research and development are initially recorded as an asset and then recognized as an expense as the related goods are delivered or services are performed. Research and development expenses include contract services, consulting, salaries, materials and supplies and overhead . Income Taxes The Company accounts for income taxes in accordance with the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification (“ASC”) 740, Income Taxes. Deferred tax assets and liabilities are recorded to reflect the impact of temporary differences between amounts of assets and liabilities for financial reporting purposes and such amounts as measured under enacted tax laws. A valuation allowance is required to offset any net deferred tax assets if, based upon the available evidence, it is more likely than not that some or all of the deferred tax asset will not be realized. The Company provides reserves for potential payments of tax to various tax authorities related to uncertain tax positions. The tax benefits recorded are based on a determination of whether and how much of a tax benefit taken by the Company in its tax filings or positions is “more likely than not” to be realized following resolution of any uncertainty related to the tax benefit, assuming that the matter in question will be raised by the tax authorities. Potential interest and penalties associated with such uncertain tax positions are recorded as a component of income tax expense. At March 31, 2023 , the Company had no such accruals. As part of the Tax Cuts and Jobs Act of 2017 ("TCJA"), beginning with the Company’s fiscal year ended December 31, 2022, the Company is required to capitalize research and development expenses, as defined under section 174 of the Internal Revenue Code of 1986, as amended. For expenses that are incurred for research and development in the United States, the amounts will be amortized over 5 years, and expenses that are incurred for research and experimentation outside the United States will be amortized over 15 years.

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Net Loss per Share	3. Net Loss per Share Net Loss per Share Attributable to Common Stockholders The following table sets forth the computation of basic and diluted net loss per share of common stock (in thousands, except share and per share data): Three Months Ended March 31, 2022 2023 Net loss $ ( 7,731 ) $ ( 11,210 ) Weighted-average shares used in computing net loss per share 27,368,354 37,800,960 Net loss per share, basic and diluted $ ( 0.28 ) $ ( 0.30 ) Basic and diluted weighted average shares of common stock outstanding for the three months ended March 31, 2023 include the weighted average effect of outstanding pre-funded warrants for the purchase of shares of common stock for which the remaining unfunded exercise price is $ 0.001 per share. The Company’s potentially dilutive securities, which include unexercised stock options outstanding, unexercised warrants and unvested restricted stock units, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect. Three Months Ended March 31, 2022 2023 Stock options to purchase common stock 3,442,152 4,640,089 Warrants to purchase common stock - 516,345 Unvested restricted stock units 42,250 333,125 Total 3,484,402 5,489,559

Investments

Investments	3 Months Ended
	Mar. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Investments	4. Investments Cash in excess of the Company’s immediate requirements is invested in accordance with the Company’s investment policy that primarily seeks to maintain adequate liquidity and preserve capital. A summary of the Company’s available-for-sale classified investments as of December 31, 2022 and March 31, 2023 consisted of the following (in thousands): At December 31, 2022 Investments - Current: Cost Basis Accumulated Unrealized Gains Accumulated Unrealized Losses Fair Value Commercial paper $ 16,741 $ - $ - $ 16,741 United States Treasury securities 15,768 7 - 15,775 United States Government Agency securities 14,584 25 - 14,609 Total $ 47,093 $ 32 $ - $ 47,125 At March 31, 2023 Investments - Current: Cost Basis Accumulated Unrealized Gains Accumulated Unrealized Losses Fair Value Commercial paper $ 15,948 $ - $ - $ 15,948 United States Government Agency securities 14,733 6 - 14,739 United States Treasury securities 9,929 2 - 9,931 Total $ 40,610 $ 8 $ - $ 40,618 The amortized cost and fair value of the Company’s available-for-sale investments, by contract maturity, as of March 31, 2023 consisted of the following (in thousands): Amortized Cost Fair Value Due in one year or less $ 40,610 $ 40,618 Total $ 40,610 $ 40,618

Inventory

Inventory	3 Months Ended
	Mar. 31, 2023
Inventory Disclosure [Abstract]
Inventory	5. Inventory The Company's inventory balance consists of the following (in thousands): December 31, March 31, Raw materials $ 1,201 $ 3,262 Work-in-process 29 - Finished goods - 359 $ 1,230 $ 3,621 Inventory is stated at the lower of cost and net realizable value and consists of raw materials, work-in-process and

Property and Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment	6. Property and Equipment Purchased property and equipment consist of the following (dollars in thousands): ESTIMATED December 31, March 31, Office equipment 5 years $ 6 $ 6 Office furniture 7 years 126 126 Computer equipment 3 years 15 15 Leasehold improvements Life of lease 95 95 242 242 Less: Accumulated depreciation ( 188 ) ( 194 ) Property and equipment, net $ 54 $ 48 Depreciation expense for the three months ended March 31, 2022 and March 31, 2023 was $ 9,000 and $ 6,000 , respectively.

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2023
Accrued Liabilities, Current [Abstract]
Accrued Expenses	7. Accrued Expenses Accrued expenses consist of the following (in thousands): December 31, March 31, Contract research and development $ 1,827 $ 1,749 Employee compensation and related costs 2,754 1,704 Accrued sales allowances and related costs - 984 Consulting and professional service fees 603 908 State taxes 49 123 Accrued royalty payable - 49 Financing related costs 29 - Interest 16 - Other 11 44 Total accrued expenses $ 5,289 $ 5,561

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	8. Fair Value of Financial Instruments FASB ASC Topic 820, Fair Value Measurements and Disclosures (“ASC 820”), provides a fair value hierarchy, which classifies fair value measurements based on the inputs used in measuring fair value. Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability, and are developed based on the best information available in the circumstances. The fair value hierarchy applies only to the valuation inputs used in determining the reported fair value of the investments and is not a measure of the investment credit quality. The three levels of the fair value hierarchy are described below: Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Valuations based on quoted prices for similar assets or liabilities in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3—Valuations that require inputs that reflect the Company’s own assumptions that are both significant to the fair value measurement and observable. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying values of the Company’s cash and restricted cash, prepaid expenses and deposits approximate their fair values due to their short-term nature. The carrying value of the Company’s loan payable is considered a reasonable estimate of fair value because the Company’s interest rate is near current market rates for instruments with similar characteristics. The following tables summarize the Company’s assets that are measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values (in thousands): As of December 31, 2022 TOTAL Quoted Prices Significant Significant Assets: Cash equivalents $ 65,875 $ 65,875 $ — $ — Total cash equivalents 65,875 65,875 — — Commercial Paper 16,741 — 16,741 — United States Treasury securities 15,775 15,775 — — United States Government Agency securities 14,609 — 14,609 — Investments 47,125 15,775 31,350 — Total $ 113,000 $ 81,650 $ 31,350 $ — Liabilities: Derivative liability $ 7,517 $ — $ — $ 7,517 Total $ 7,517 $ — $ — $ 7,517 As of March 31, 2023 TOTAL Quoted Prices Significant Significant Assets: Cash equivalents $ 69,419 $ 69,419 $ — $ — Total cash equivalents 69,419 69,419 — — Commercial Paper 15,948 — 15,948 — United States Government Agency securities 14,739 — 14,739 — United States Treasury securities 9,931 9,931 — — Investments 40,618 9,931 30,687 — Total $ 110,037 $ 79,350 $ 30,687 $ — Liabilities: Derivative liability $ 6,510 $ — $ — $ 6,510 Total $ 6,510 $ — $ — $ 6,510 Changes in the fair value of the Company's Level 3 derivative liability for the three months ended March 31, 2023 are as follows (in thousands): At December 31, 2022 $ 7,517 Change in fair value of derivative liability ( 1,007 ) At March 31, 2023 $ 6,510

Debt

Debt	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Debt	9. Debt The following table presents the carrying value of the Company's debt balance as of December 31, 2022 and March 31, 2023 (in thousands): December 31, March 31, Face value $ 50,000 $ 50,000 Less: discount ( 13,206 ) ( 12,748 ) Total 36,794 37,252 Less: current portion — — Long-term portion $ 36,794 $ 37,252 Oaktree Agreement On October 13, 2022 (“Closing Date”), the Company entered into a Credit Agreement and Guaranty (the “Oaktree Agreement”) with Oaktree Fund Administration, LLC as administrative agent, and the lenders party thereto (collectively “Oaktree”) to borrow up to $ 100.0 million in three tranches with a maturity date of October 13, 2027 . The first tranche of $ 50.0 million was drawn immediately, with $ 9.8 million of the proceeds used to repay in full the outstanding loan and fees under the 2019 Loan Agreement with SLR Investment Corp. and Silicon Valley Bank and $ 2.7 million in fees and expenses incurred in connection with the financing, leaving $ 37.5 million in available proceeds from the first tranche. The ability to draw the remaining $ 50.0 million is contingent upon reaching certain net sales revenue milestone targets prior to September 30, 2024 and December 31, 2024, respectively. The term loan initially bears interest at the three-month term Secured Overnight Financing Rate (“SOFR”) plus an applicable margin of 8.75 % (with a SOFR floor of 1.00 % and a 3.00 % cap). Once FUROSCIX achieves at least $ 100.0 million in trailing 12-month net sales, the applicable margin will step down to 8.25 %. The Company is required to make quarterly interest-only payments until the third anniversary of the Closing Date, after which the Company is required to make quarterly amortizing payments, with the remaining balance of the principal plus accrued and unpaid interest due at maturity. In connection with entering into the Oaktree Agreement, the Company granted warrants to Oaktree to purchase up to an aggregate of 516,345 shares of the Company’s common stock at an exercise price of $ 5.40 per share. Upon inception, the Company evaluated the warrants and determined that they met all the requirements for equity classification under ASC Topic 815 Derivatives and Hedging ("ASC 815"). This transaction was accounted for as a detachable warrant at its fair value, using the relative fair value method, which is based on a number of unobservable inputs and is recorded as an increase to additional paid-in-capital on the consolidated statement of stockholder’s equity. The relative fair value of the warrants, $ 2.0 million, was reflected as a discount to the term loan and will be amortized over the life of the term loan using the effective interest method. The Company used the Black-Scholes option pricing model to determine the fair value of the warrants. Assumptions included the fair market value per share of common stock on the valuation date of $ 5.50 , the exercise price per warrant equal to $ 5.40 , the expected volatility of 77 %, the risk-free interest rate of 4.11 %, the expected term of 7 years and the absence of a dividend. The warrants are immediately exercisable and the exercise period expires on October 13, 2029. The Company identified a number of embedded derivatives that require bifurcation from the term loan and that were separately accounted for in the consolidated financial statements as one compound derivative liability. Certain of these embedded features include contingent interest rate reset upon event of default, contingent put options, including change in control and going concern provisions, and additional costs as a result of changes in law. These embedded features met the criteria requiring these to be bifurcated because they were not clearly and closely related to the host instrument in accordance with ASC 815-15 and the derivative liability is presented separately in the condensed consolidated balance sheet as of March 31, 2023. The fair value of the embedded derivative liabilities associated with the term loan was estimated using a hybrid between the discounted cash flow and Monte Carlo simulation methods. This involves significant Level 3 inputs and assumptions including an estimated probability and timing of a change in control. The Company re-evaluates this assessment each reporting period and any changes in estimated fair value is recorded as other income (expense). The initial recognition of the embedded derivative liability upon issuance of the Term Loan was $ 8.9 million. At March 31, 2023, the fair value of the embedded derivative liability was $ 6.5 million. In connection with the issuance of the term loan, the Company recorded a debt discount of $ 13.6 million, inclusive of debt issuance costs, the derivative liability and the relative fair value of the warrants. The discount will be amortized over the life of the term loan using the effective interest method. For the three months ended March 31, 2023, the Company recorded $ 459,000 related to the amortization of the debt discount associated with the Oaktree Agreement. Prepayments of the term loan, in whole or in part, will be subject to a prepayment fee which declines each year until the fourth anniversary date of the Closing Date, after which no prepayment fee is required. The Company is also required to pay an exit fee upon any payment or prepayment equal to 2.0 % of the aggregate principal amount of the loans funded under the Oaktree Agreement. The Company recorded an additional debt discount of $ 1.0 million related to the exit fee. For the three months ended March 31, 2023, the Company recorded $ 34,000 related to the amortization of the exit fee associated with the Oaktree Agreement. The Oaktree Agreement contains customary representations, warranties and affirmative and negative covenants, including financial covenants requiring the Company to (i) maintain unrestricted cash of at least $ 15.0 million at all times, increasing to $ 20.0 million upon accessing the second tranche of the term loan and (ii) meet minimum quarterly net sales revenue targets. In addition, the Oaktree Agreement contains customary events of default that could cause the Company’s indebtedness to become immediately due and payable. The lenders could declare the Company in default under its debt obligation upon the occurrence of any event that the lenders interpret as having a material adverse effect as defined under the Oaktree Agreement. Upon the occurrence and for the duration of an event of default, an additional interest rate equal to 2.0 % per annum could apply to all obligations owed under the Oaktree Agreement. Among other loan covenant requirements, the Oaktree Agreement also requires the Company to provide an audit opinion of its annual financial statements not subject to any "going concern" or like qualification or exception. SLR Investment Corp. and Silicon Valley Bank Term Loan In May 2017, the Company entered into a loan and security agreement (the “2017 Loan Agreement”), with SLR Investment Corp. (f/k/a Solar Capital Ltd.) and Silicon Valley Bank (together, the “Lenders”), for $ 10.0 million. In September 2019, the Company replaced the 2017 Loan Agreement with a new $ 20.0 million term loan with the Lenders (the “2019 Loan Agreement”). The 2019 Loan Agreement extended the term of the credit facility until September 17, 2023 . Debt issuance costs for the 2019 Loan Agreement, including unamortized issuance costs for the 2017 Loan Agreement, were to be amortized to interest expense over the remaining term of the 2019 Loan Agreement using the effective-interest method. The interest rate under the 2019 Loan Agreement was the higher of (i) LIBOR plus 7.95 % or (ii) 10.18 % and there was an interest-only period until September 30, 2021. The rate at December 31, 2022 was 10.18 %. Pursuant to the 2019 Loan Agreement, the Company provided a first priority security interest in substantially all of the Company’s assets, including intellectual property, subject to certain exceptions. The Company entered into an Exit Agreement in connection with the 2019 Loan Agreement which provided for an aggregate payment of 4 % of the loan commitment, or $ 800,000 , to the lenders upon the occurrence of an exit event (the “Exit Fee”). The Company paid the Exit Fee during 2020 in conjunction with the Company’s public offering, which was deemed to be an exit event pursuant to the Exit Agreement. The 2019 Loan Agreement allowed the Company to voluntarily prepay all (but not less than all) of the outstanding principal at any time. A prepayment premium of 3 % or 1 % through the one-year anniversary and the two-year anniversary, respectively, would be assessed on the outstanding principal. After the two-year anniversary, a 0.5 % prepayment premium would be assessed on the outstanding principal. A final payment fee of $ 500,000 was due upon the earlier to occur of the maturity date or prepayment of such borrowings. In connection with the Oaktree Agreement, the Company paid off all unpaid borrowings under the 2019 Loan Agreement on October 13, 2022, including the $ 500,000 final fee and a prepayment premium of $ 46,000 . For the three months ended March 31, 2022, the Company recorded $ 87,000 related to the amortization of debt discount associated with the 2019 Loan Agreement. For the three months ended March 31, 2022, the Company recorded $ 34,000 related to the amortization of the final payment fee associated with the 2019 Loan Agreement. In an event of default under the 2019 Loan Agreement, the interest rate would have been increased by 5 % and the balance under the loan may have become immediately due and payable at the option of the lenders. The 2019 Loan Agreement included restrictions on, among other things, the Company’s ability to incur additional indebtedness, change the name or location of the Company’s business, merge with or acquire other entities, pay dividends or make other distributions to holders of its capital stock, make certain investments, engage in transactions with affiliates, create liens, sell assets or pay subordinated debt. As of March 31, 2023, future principal payments due under the Oaktree Agreement were as follows (in thousands): Year ended: December 31, 2023 $ — December 31, 2024 — December 31, 2025 2,500 December 31, 2026 10,000 December 31, 2027 37,500 Total $ 50,000

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2023
Equity [Abstract]
Stockholders' Equity	10. Stockholders’ Equity 2021 At-the-Market Issuance Sales Agreement On March 23, 2021, the Company entered into an Open Market Sale Agreement (the “2021 ATM Agreement”) with Cowen and Company, LLC (“Cowen”) with respect to an at-the-market offering program under which the Company could offer and sell shares of its common stock (the “2021 ATM Shares”), having an aggregate offering price of up to $ 50.0 million through Cowen as its sales agent. The Company agreed to pay Cowen a commission up to 3.0 % of the gross sales proceeds of such 2021 ATM Shares. During the three months ended March 31, 2023 , the Company sold 1,511,157 shares of its common stock under the 2021 ATM Agreement at a weighted average gross selling price of $ 9.30 per share for net proceeds of $ 13.7 million.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	11. Stock-Based Compensation Stock Options The Company’s 2017 Stock Option and Incentive Plan (the “2017 Stock Plan”) became effective in November 2017 , upon the closing of the Company’s initial public offering and will expire in October 2027 . Under the 2017 Stock Plan, the Company may grant incentive stock options, non-statutory stock options, restricted stock awards, restricted stock units (“RSUs”) and other stock-based awards. The Company’s 2014 Stock Incentive Plan (the “2014 Stock Plan”) was terminated in November 2017 effective upon the completion of the Company’s initial public offering and no further options will be granted under the 2014 Stock Plan. At March 31, 2023 , there were 598,411 options outstanding under the 2014 Stock Plan. As of March 31, 2023 , there were 7,475,463 shares of the Company’s common stock authorized for issuance under the 2017 Stock Plan, including 359,860 options that have been forfeited from the 2014 Stock Plan. At March 31, 2023 , there were 3,199,318 options available for issuance under the 2017 Stock Plan, 3,902,928 options outstanding and 333,125 RSUs outstanding. On February 1, 2023, the Board of Directors of the Company adopted the 2023 Employment Inducement Award Plan (the "Inducement Plan") and, subject to the adjustment provisions of the Inducement Plan, reserved 500,000 shares of the Company’s common stock for issuance pursuant to equity awards granted under the Inducement Plan. At March 31, 2023, there were 361,250 options available for issuance under the Inducement Plan, and 138,750 options outstanding. Awards granted under the 2017 Stock Plan and the Inducement Plan have a term of ten years . Vesting of awards under the 2017 Stock Plan and Inducement Plan is determined by the board of directors, but is generally over one to four-year terms. The fair value of options at date of grant was estimated using the Black-Scholes option-pricing model with the following assumptions: Three Months Ended 2022 2023 Risk-free interest rate 1.67 % - 1.90 % 3.40 % - 4.17 % Expected dividend yield 0 % 0 % Expected life 5.6 - 6.7 years 5.6 - 7.0 years Expected volatility 70 %- 72 % 77 %- 85 % Weighted-average grant date fair value $ 2.93 $ 4.60 The following table summarizes information about stock option activity during the three months ended March 31, 2023 (in thousands, except share and per share data): NUMBER OF WEIGHTED- WEIGHTED- AGGREGATE Outstanding, December 31, 2022 4,008,177 $ 5.76 Granted 652,462 6.31 Forfeited ( 20,550 ) 5.33 Outstanding, March 31, 2023 4,640,089 $ 5.84 7.58 $ 15,792 Vested and exercisable, March 31, 2023 2,283,867 $ 6.01 6.12 $ 7,774 Vested and expected to vest, March 31, 2023 4,014,732 $ 5.86 7.34 $ 13,687 The following table summarizes information about RSU activity during the three months ended March 31, 2023: RSUs AVERAGE GRANT RSUs outstanding, December 31, 2022 — $ — Granted 335,410 6.14 Forfeited ( 2,285 ) 6.14 RSUs outstanding at March 31, 2023 333,125 $ 6.14 Unrecognized compensation expense related to unvested options as of March 31, 2023 was $ 5.7 million and will be recognized over the remaining vesting periods of the underlying awards. The weighted-average period over which such compensation is expected to be recognized is 2.7 years. Unrecognized compensation expense related to unvested RSUs as of March 31, 2023 was $ 1.2 million and will be recognized over the remaining vesting periods of the underlying awards. The weighted-average period over which such compensation is expected to be recognized is 3.8 years. Employee Stock Purchase Plan In October 2017, the board of directors approved the 2017 Employee Stock Purchase Plan (the "ESPP") which became effective in November 2017, upon the closing of the Company's IPO. As part of the ESPP, eligible employees may acquire an ownership interest in the Company by purchasing common stock, at a discount, through payroll deductions. Eligible employees who elected to participate were able to participate in the ESPP beginning September 1, 2021. As of March 31, 2023 , there were 1,347,691 shares of common stock available for issuance under the ESPP. The Company recorded stock-based compensation expense in the following expense categories of its accompanying condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2022 and 2023 (in thousands): Three Months Ended March 31, 2022 2023 Research and development $ 254 $ 340 General and administrative 382 640 Total $ 636 $ 980

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	12. Commitments and Contingencies Operating Leases The Company leases office facilities and equipment under long-term, non-cancelable operating lease agreements. The leases expire at various dates through 2025 and do not include renewal options. Certain leases provide for increases in future minimum annual rental payments as defined in the lease agreements. The leases generally also include real estate taxes and common area maintenance charges in the annual rental payments. Short-term leases are leases having a term of twelve months or less. The Company recognizes short-term leases on a straight-line basis and does no t record a related lease asset or liability for such leases. The following is a maturity analysis of the annual undiscounted cash flows of the operating lease liabilities as of March 31, 2023 (in thousands): Year ended: December 31, 2023 $ 433 December 31, 2024 9 December 31, 2025 1 Total minimum lease payments 443 Less imputed interest ( 19 ) Total $ 424 Three Months Ended 2022 2023 Lease cost: Operating lease cost $ 118 $ 112 Short-term lease cost 13 9 Sublease income ( 13 ) - Total lease cost $ 118 $ 121 Other information Cash paid for amounts included in the measurement of lease liabilities $ 140 $ 163 Operating cash flows from operating leases $ ( 18 ) $ ( 50 ) Weighted-average remaining lease term - operating leases 0.8 years 0.7 years Weighted-average discount rate - operating leases 10.1 % 10.1 % Research and Development Agreements As part of the Company’s research and development efforts, the Company enters into research and development agreements with certain companies. These agreements contain varying terms and provisions which include fees and milestones to be paid by the Company. Some of these agreements also contain provisions which require the Company to make payments for exclusivity in the development of products in the area of loop diuretics.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. 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 reported periods. Actual results could differ from those estimates.
Cash Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash Cash, cash equivalents and restricted cash consists of bank deposits and money market accounts with financial institutions. Cash equivalents are carried at cost which approximates fair value due to their short-term nature and which the Company believes do not have a material exposure to credit risk. The Company considers all highly liquid investments with maturities of three months or less from the date of purchase to be cash equivalents. The Company’s cash and cash equivalent accounts, at times, may exceed federally insured limits. The Company has not experienced any losses in such accounts. Cash, cash equivalents and restricted cash consists of the following (in thousands): December 31, March 31, Cash and cash equivalents $ 71,061 $ 75,453 Restricted cash 182 - Cash, cash equivalents and restricted cash $ 71,243 $ 75,453
Accounts Receivable	Accounts Receivable Accounts receivable are recorded net of any estimated expected credit losses. The Company's measurement of expected credit losses is based on relevant information about past events, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. To date, expected credit losses have not been material.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that subject the Company to credit risk primarily consist of cash and cash equivalents and short-term investments. The Company maintains its cash and cash equivalent balances with high-quality financial institutions and, consequently, the Company believes that such funds are subject to minimal credit risk. The Company’s short-term investments consist of United States Treasury securities, commercial paper and United States Government Agency securities. The Company has adopted an investment policy that limits the amounts the Company may invest in any one type of investment and requires all investments held by the Company to hold a minimum rating, thereby reducing credit risk exposure As the Company executes its commercial launch, the Company has a limited number of specialty pharmacy customers. As of, and for the quarter ended, March 31, 2023, one customer represents 92 % of accounts receivable and revenue, respectively.
Investments	Investments The Company invests excess cash balances in available-for-sale debt securities. The Company determines the appropriate classification of these securities at the time they are acquired and evaluates the appropriateness of such classifications at each balance sheet date. The Company reports available-for-sale investments at fair value at each balance sheet date and includes any unrealized gains and losses in accumulated other comprehensive income (loss), a component of stockholders’ equity. Realized gains and losses are determined using the specific identification method and are included in other income (expense). If any adjustment to fair value reflects a decline in the value of the investment, the Company considers all available evidence to evaluate the extent to which the decline is “other than temporary,” including the intention to sell and, if so, marks the investment to market through a charge to the Company’s consolidated statements of operations and comprehensive loss
Inventory	Inventory Inventory is stated at the lower of cost and net realizable value and consists of raw materials, work-in-process and finished goods. The Company began capitalizing inventory costs following U.S. Food and Drug Administration ("FDA") approval of FUROSCIX on October 7, 2022. Inventory is sold on a first in, first out ("FIFO") basis. The Company periodically reviews inventory for expiry and obsolescence and writes it down accordingly, if necessary. Prior to FDA approval of FUROSCIX, the Company expensed all inventory-related costs, including that used for clinical development, to research and development ("R&D") costs in the period incurred.
Leases	Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in right-of-use (“ROU”) lease assets, current portion of lease obligations, and long-term lease obligations on the Company’s balance sheets. ROU lease assets represent the Company’s right to use an underlying asset for the lease term and lease obligations represent the Company’s obligation to make lease payments arising from the lease. Operating ROU lease assets and obligations are recognized at the commencement date based on the present value of lease payments over the lease term. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The ROU lease asset excludes lease incentives. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term
Debt Issuance Costs	Debt Issuance Costs Debt issuance costs are amortized to interest expense using the effective interest rate method over the term of the debt. Debt issuance costs paid to the lender and third parties are reflected as a discount to the debt in the consolidated balance sheets
Revenue Recognition	Revenue Recognition The Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangement that the Company determines are within the scope of Accounting Standards Codification ("ASC") Topic 606, Revenue from Contracts with Customer (“Topic 606”), the Company 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 the Company satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that it 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 the performance obligation is satisfied. The Company has identified one performance obligation, the delivery of FUROSCIX to its customers. The Company has not incurred any incremental costs associated with obtaining contracts with customers. The Company’s revenues consist solely of the sale of FUROSCIX to customers in the United States. Product Net Sales FUROSCIX was approved by the FDA on October 7, 2022. The Company launched sales of FUROSCIX in the first quarter of 2023 to specialty pharmacies (“SPs”). The Company recognizes revenue from product sales at a point in time, typically upon receipt of product at the SPs, the date at which the rights, title, interest and risk of loss are transferred. Revenues from product sales are recorded at the net sales price, which includes estimates of variable consideration that result from (a) sales discounts, (b) rebates (c) co-pay assistance, and (d) product returns. Reserves are established for the estimates of variable consideration based on the amounts earned or to be claimed on the related sales. The reserves for variable consideration are reflected as either as a reduction to the related account receivable or as an accrued liability, depending on how the consideration is settled. The amount of variable consideration that is included in the transaction price may be constrained and is included in net product revenues only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. Actual amounts of consideration ultimately received may differ from the Company's estimates. If actual results vary from its estimates, the Company adjusts these estimates, which would affect net product revenue and earnings in the period such variances become known. Sales Discounts : Sales discounts are agreed-upon discounts, from negotiated contracts, taken directly off the Company’s sales invoices. Sales discounts are recorded as an offset to revenue based on contractual terms at the time revenue from the sale is recognized. Rebates : Allowance for rebates include mandated discounts under the Medicaid Drug Rebate Program and the Medicare Part D prescription drug benefit, TRICARE program and contractual rebates with commercial payers. Rebates are amounts owed after the final dispensing of the product to a benefit plan participant and are based upon contractual agreements or statutory requirements. The allowance for rebates is based on contracted or statutory discount rates and expected utilization by benefit plan participants. The Company’s estimates for expected utilization of rebates are based on utilization data received from the SPs since product launch. Rebates are generally invoiced and paid in arrears so that the accrual balance consists of an estimate of the amount expected to be incurred for the current quarter’s activity, plus an accrual balance for prior quarters’ unpaid rebates. If actual future rebates vary from estimates, the Company may need to adjust prior period accruals, which would affect revenue in the period of adjustment. Co-Payment Assistance: The Company offers co-payment assistance to commercially insured patients meeting certain eligibility requirement. Co-payment assistance is accrued at the time of product sale to SPs based on estimated patient participation and average co-pay benefit to be paid per a claim. The Company’s estimated amounts are compared to actual program participation and co-pay amounts paid using data provided by third-party administrators. If actual amounts differ from the original estimates the assumptions being applied are updated and adjustment for prior period accruals will be adjusted in the current period. Product Returns: Consistent with industry practice, the Company offers SPs limited product return rights for damages, shipment errors, and expiring product, provided that the return is within a specified period around the product expiration date as set forth in the applicable individual distribution agreement. The Company does not allow product returns for product that has been dispensed to a patient. As the Company receives inventory reports from the SPs and has the ability to control the amount of product that is sold to the SPs, it is able to make a reasonable estimate of future potential product returns based on this on-hand channel inventory data and sell-through data obtained from the SPs. In arriving at its estimate, the Company also considers historical product returns, the underlying product demand, and industry data specific to the specialty pharmaceutical distribution industry.
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred. Nonrefundable advance payments, if any, for goods or services used in research and development are initially recorded as an asset and then recognized as an expense as the related goods are delivered or services are performed. Research and development expenses include contract services, consulting, salaries, materials and supplies and overhead
Income Taxes	Income Taxes The Company accounts for income taxes in accordance with the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification (“ASC”) 740, Income Taxes. Deferred tax assets and liabilities are recorded to reflect the impact of temporary differences between amounts of assets and liabilities for financial reporting purposes and such amounts as measured under enacted tax laws. A valuation allowance is required to offset any net deferred tax assets if, based upon the available evidence, it is more likely than not that some or all of the deferred tax asset will not be realized. The Company provides reserves for potential payments of tax to various tax authorities related to uncertain tax positions. The tax benefits recorded are based on a determination of whether and how much of a tax benefit taken by the Company in its tax filings or positions is “more likely than not” to be realized following resolution of any uncertainty related to the tax benefit, assuming that the matter in question will be raised by the tax authorities. Potential interest and penalties associated with such uncertain tax positions are recorded as a component of income tax expense. At March 31, 2023 , the Company had no such accruals. As part of the Tax Cuts and Jobs Act of 2017 ("TCJA"), beginning with the Company’s fiscal year ended December 31, 2022, the Company is required to capitalize research and development expenses, as defined under section 174 of the Internal Revenue Code of 1986, as amended. For expenses that are incurred for research and development in the United States, the amounts will be amortized over 5 years, and expenses that are incurred for research and experimentation outside the United States will be amortized over 15 years.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Schedule of Cash, Cash Equivalents and Restricted Cash	Cash, cash equivalents and restricted cash consists of the following (in thousands): December 31, March 31, Cash and cash equivalents $ 71,061 $ 75,453 Restricted cash 182 - Cash, cash equivalents and restricted cash $ 71,243 $ 75,453

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Loss Per Share of Common Stock	The following table sets forth the computation of basic and diluted net loss per share of common stock (in thousands, except share and per share data): Three Months Ended March 31, 2022 2023 Net loss $ ( 7,731 ) $ ( 11,210 ) Weighted-average shares used in computing net loss per share 27,368,354 37,800,960 Net loss per share, basic and diluted $ ( 0.28 ) $ ( 0.30 )
Schedule of Antidilutive Securities Excluded from Computation of Net Loss Per Share	The Company’s potentially dilutive securities, which include unexercised stock options outstanding, unexercised warrants and unvested restricted stock units, have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect. Three Months Ended March 31, 2022 2023 Stock options to purchase common stock 3,442,152 4,640,089 Warrants to purchase common stock - 516,345 Unvested restricted stock units 42,250 333,125 Total 3,484,402 5,489,559

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Summary of Available-for-Sale Classified Investments	A summary of the Company’s available-for-sale classified investments as of December 31, 2022 and March 31, 2023 consisted of the following (in thousands): At December 31, 2022 Investments - Current: Cost Basis Accumulated Unrealized Gains Accumulated Unrealized Losses Fair Value Commercial paper $ 16,741 $ - $ - $ 16,741 United States Treasury securities 15,768 7 - 15,775 United States Government Agency securities 14,584 25 - 14,609 Total $ 47,093 $ 32 $ - $ 47,125 At March 31, 2023 Investments - Current: Cost Basis Accumulated Unrealized Gains Accumulated Unrealized Losses Fair Value Commercial paper $ 15,948 $ - $ - $ 15,948 United States Government Agency securities 14,733 6 - 14,739 United States Treasury securities 9,929 2 - 9,931 Total $ 40,610 $ 8 $ - $ 40,618
Summary of Amortized Cost and Fair Value of Available-for-Sale Investments by Contract Maturity	The amortized cost and fair value of the Company’s available-for-sale investments, by contract maturity, as of March 31, 2023 consisted of the following (in thousands): Amortized Cost Fair Value Due in one year or less $ 40,610 $ 40,618 Total $ 40,610 $ 40,618

Inventory (Tables)

Inventory (Tables)	3 Months Ended
	Mar. 31, 2023
Inventory Disclosure [Abstract]
Schedule of Inventory	The Company's inventory balance consists of the following (in thousands): December 31, March 31, Raw materials $ 1,201 $ 3,262 Work-in-process 29 - Finished goods - 359 $ 1,230 $ 3,621

Property and Equipment (Tables)

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Schedule of Purchased Property and Equipment	Purchased property and equipment consist of the following (dollars in thousands): ESTIMATED December 31, March 31, Office equipment 5 years $ 6 $ 6 Office furniture 7 years 126 126 Computer equipment 3 years 15 15 Leasehold improvements Life of lease 95 95 242 242 Less: Accumulated depreciation ( 188 ) ( 194 ) Property and equipment, net $ 54 $ 48

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2023
Accrued Liabilities, Current [Abstract]
Schedule of Accrued Expenses	Accrued expenses consist of the following (in thousands): December 31, March 31, Contract research and development $ 1,827 $ 1,749 Employee compensation and related costs 2,754 1,704 Accrued sales allowances and related costs - 984 Consulting and professional service fees 603 908 State taxes 49 123 Accrued royalty payable - 49 Financing related costs 29 - Interest 16 - Other 11 44 Total accrued expenses $ 5,289 $ 5,561

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Summary of Assets Measured at Fair Value on Recurring Basis	The following tables summarize the Company’s assets that are measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values (in thousands): As of December 31, 2022 TOTAL Quoted Prices Significant Significant Assets: Cash equivalents $ 65,875 $ 65,875 $ — $ — Total cash equivalents 65,875 65,875 — — Commercial Paper 16,741 — 16,741 — United States Treasury securities 15,775 15,775 — — United States Government Agency securities 14,609 — 14,609 — Investments 47,125 15,775 31,350 — Total $ 113,000 $ 81,650 $ 31,350 $ — Liabilities: Derivative liability $ 7,517 $ — $ — $ 7,517 Total $ 7,517 $ — $ — $ 7,517 As of March 31, 2023 TOTAL Quoted Prices Significant Significant Assets: Cash equivalents $ 69,419 $ 69,419 $ — $ — Total cash equivalents 69,419 69,419 — — Commercial Paper 15,948 — 15,948 — United States Government Agency securities 14,739 — 14,739 — United States Treasury securities 9,931 9,931 — — Investments 40,618 9,931 30,687 — Total $ 110,037 $ 79,350 $ 30,687 $ — Liabilities: Derivative liability $ 6,510 $ — $ — $ 6,510 Total $ 6,510 $ — $ — $ 6,510
Schedule of Changes in Fair Value of Level 3 Derivative Liability	Changes in the fair value of the Company's Level 3 derivative liability for the three months ended March 31, 2023 are as follows (in thousands): At December 31, 2022 $ 7,517 Change in fair value of derivative liability ( 1,007 ) At March 31, 2023 $ 6,510

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Schedule of Carrying Value of Debt Balnce	The following table presents the carrying value of the Company's debt balance as of December 31, 2022 and March 31, 2023 (in thousands): December 31, March 31, Face value $ 50,000 $ 50,000 Less: discount ( 13,206 ) ( 12,748 ) Total 36,794 37,252 Less: current portion — — Long-term portion $ 36,794 $ 37,252
Schedule of Future Principal Payments Due	As of March 31, 2023, future principal payments due under the Oaktree Agreement were as follows (in thousands): Year ended: December 31, 2023 $ — December 31, 2024 — December 31, 2025 2,500 December 31, 2026 10,000 December 31, 2027 37,500 Total $ 50,000

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Schedule of Estimated Fair Value of Options Valuation Assumptions	The fair value of options at date of grant was estimated using the Black-Scholes option-pricing model with the following assumptions: Three Months Ended 2022 2023 Risk-free interest rate 1.67 % - 1.90 % 3.40 % - 4.17 % Expected dividend yield 0 % 0 % Expected life 5.6 - 6.7 years 5.6 - 7.0 years Expected volatility 70 %- 72 % 77 %- 85 % Weighted-average grant date fair value $ 2.93 $ 4.60
Summary of Information about Stock Option Activity	The following table summarizes information about stock option activity during the three months ended March 31, 2023 (in thousands, except share and per share data): NUMBER OF WEIGHTED- WEIGHTED- AGGREGATE Outstanding, December 31, 2022 4,008,177 $ 5.76 Granted 652,462 6.31 Forfeited ( 20,550 ) 5.33 Outstanding, March 31, 2023 4,640,089 $ 5.84 7.58 $ 15,792 Vested and exercisable, March 31, 2023 2,283,867 $ 6.01 6.12 $ 7,774 Vested and expected to vest, March 31, 2023 4,014,732 $ 5.86 7.34 $ 13,687
Schedule of RSU Activity	The following table summarizes information about RSU activity during the three months ended March 31, 2023: RSUs AVERAGE GRANT RSUs outstanding, December 31, 2022 — $ — Granted 335,410 6.14 Forfeited ( 2,285 ) 6.14 RSUs outstanding at March 31, 2023 333,125 $ 6.14
Summary of Stock-Based Compensation Expense	The Company recorded stock-based compensation expense in the following expense categories of its accompanying condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2022 and 2023 (in thousands): Three Months Ended March 31, 2022 2023 Research and development $ 254 $ 340 General and administrative 382 640 Total $ 636 $ 980

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Schedule of Maturity Analysis of Annual Undiscounted Cash Flows of Operating Lease Liabilities	The following is a maturity analysis of the annual undiscounted cash flows of the operating lease liabilities as of March 31, 2023 (in thousands): Year ended: December 31, 2023 $ 433 December 31, 2024 9 December 31, 2025 1 Total minimum lease payments 443 Less imputed interest ( 19 ) Total $ 424
Schedule of Lease Cost and Other Information of Operating Lease Liabilities	Three Months Ended 2022 2023 Lease cost: Operating lease cost $ 118 $ 112 Short-term lease cost 13 9 Sublease income ( 13 ) - Total lease cost $ 118 $ 121 Other information Cash paid for amounts included in the measurement of lease liabilities $ 140 $ 163 Operating cash flows from operating leases $ ( 18 ) $ ( 50 ) Weighted-average remaining lease term - operating leases 0.8 years 0.7 years Weighted-average discount rate - operating leases 10.1 % 10.1 %

Description of Business and B_2

Description of Business and Basis of Presentation - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$ (237,746)	$ (226,536)
Cash, cash equivalents, restricted cash, and short-term investments	$ 116,100

Significant Accounting Polici_4

Significant Accounting Policies - Schedule of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 75,453	$ 71,061
Restricted cash		182
Cash, cash equivalents and restricted cash	$ 75,453	$ 71,243	$ 51,812	$ 74,450

Significant Accounting Polici_5

Significant Accounting Policies - Additional Information (Details)	3 Months Ended
	Mar. 31, 2023 USD ($) Customer
Schedule Of Accounting Policies [Line Items]
Potential interest and penalties associated with uncertain tax positions, accruals | $	$ 0
Amortized period for expenses incurred for research and development in united states	5 years
Amortized period for expenses incurred for research and development outside united states	15 years
Number of Customer | Customer	1
Customer Concentration Risk | Accounts Receivable | Customer One
Schedule Of Accounting Policies [Line Items]
Percentage of concentration risk	92%
Customer Concentration Risk | Revenue | Customer One
Schedule Of Accounting Policies [Line Items]
Percentage of concentration risk	92%

Net Loss per Share - Computatio

Net Loss per Share - Computation of Basic and Diluted Net Loss Per Share of Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Earnings Per Share [Abstract]
Net loss	$ (11,210)	$ (7,731)
Weighted-average shares used in computing net loss per share, basic	37,800,960	27,368,354
Weighted-average shares used in computing net loss per share, diluted	37,800,960	27,368,354
Net loss per share, basic	$ (0.30)	$ (0.28)
Net loss per share, diluted	$ (0.30)	$ (0.28)

Net Loss per Share (Additional

Net Loss per Share (Additional Information) (Details)	Mar. 31, 2023 $ / shares
Earnings Per Share [Abstract]
Exercise price per share	$ 0.001

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Antidilutive Securities Excluded from Computation of Net Loss Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	5,489,559	3,484,402
Stock Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	4,640,089	3,442,152
Warrants to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	516,345
Unvested Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	333,125	42,250

Investments - Summary of Availa

Investments - Summary of Available-for-Sale Classified Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Marketable Securities [Line Items]
Cost Basis	$ 40,610	$ 47,093
Accumulated Unrealized Gains	8	32
Fair Value	40,618	47,125
Commercial Paper
Marketable Securities [Line Items]
Cost Basis	15,948	16,741
Fair Value	15,948	16,741
United States Treasury Securities
Marketable Securities [Line Items]
Cost Basis	9,929	15,768
Accumulated Unrealized Gains	2	7
Fair Value	9,931	15,775
United States Government Agency Securities
Marketable Securities [Line Items]
Cost Basis	14,733	14,584
Accumulated Unrealized Gains	6	25
Fair Value	$ 14,739	$ 14,609

Investments - Summary of Amorti

Investments - Summary of Amortized Cost and Fair Value of Available-for-Sale Investments by Contract Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Amortized Cost, Due in one year or less	$ 40,610
Amortized Cost, Total	40,610	$ 47,093
Fair Value, Due in one year or less	40,618
Fair Value, Total	$ 40,618	$ 47,125

Inventory - Schedule of Invento

Inventory - Schedule of Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Inventory Disclosure [Abstract]
Raw materials	$ 3,262	$ 1,201
Work-in-process		29
Finished goods	359
Inventory, Net, Total	$ 3,621	$ 1,230

Property and Equipment - Schedu

Property and Equipment - Schedule of Purchased Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 242	$ 242
Less: Accumulated depreciation	(194)	(188)
Property and equipment, net	$ 48	54
Office Equipment
Property Plant And Equipment [Line Items]
ESTIMATED USEFUL LIFE	5 years
Property and equipment, gross	$ 6	6
Office Furniture
Property Plant And Equipment [Line Items]
ESTIMATED USEFUL LIFE	7 years
Property and equipment, gross	$ 126	126
Computer Equipment
Property Plant And Equipment [Line Items]
ESTIMATED USEFUL LIFE	3 years
Property and equipment, gross	$ 15	15
Leasehold Improvements
Property Plant And Equipment [Line Items]
ESTIMATED USEFUL LIFE	Life of lease
Property and equipment, gross	$ 95	$ 95

Property and Equipment - Additi

Property and Equipment - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 6,000	$ 9,000

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Accrued Liabilities, Current [Abstract]
Contract research and development	$ 1,749	$ 1,827
Employee compensation and related costs	1,704	2,754
Accrued sales allowances and related costs	984
Consulting and professional service fees	908	603
State taxes	123	49
Accrued royalty payable	49
Financing related costs		29
Interest		16
Other	44	11
Total accrued expenses	$ 5,561	$ 5,289

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Summary of Assets Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Liabilities:
Derivative liability	$ 6,510	$ 7,517
Fair Value, Measurements, Recurring
Assets:
Cash equivalents	69,419	65,875
Investments	40,618	47,125
Total	110,037	113,000
Liabilities:
Derivative liability	6,510	7,517
Total	6,510	7,517
Fair Value, Measurements, Recurring | Commercial Paper
Assets:
Investments	15,948	16,741
Fair Value, Measurements, Recurring | United States Treasury Securities
Assets:
Investments	9,931	15,775
Fair Value, Measurements, Recurring | United States Government Agency Securities
Assets:
Investments	14,739	14,609
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1) [Member]
Assets:
Cash equivalents	69,419	65,875
Investments	9,931	15,775
Total	79,350	81,650
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1) [Member] | United States Treasury Securities
Assets:
Investments	9,931	15,775
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) [Member]
Assets:
Investments	30,687	31,350
Total	30,687	31,350
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) [Member] | Commercial Paper
Assets:
Investments	15,948	16,741
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) [Member] | United States Government Agency Securities
Assets:
Investments	14,739	14,609
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) [Member]
Liabilities:
Derivative liability	6,510	7,517
Total	$ 6,510	$ 7,517

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Schedule of Changes in Fair Value of Level 3 Derivative Liability (Details) - Significant Unobservable Inputs (Level 3) [Member] $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 7,517
Change in fair value of derivative liability	$ (1,007)
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)
Ending balance	$ 6,510

Debt - Schedule of Carrying Val

Debt - Schedule of Carrying Value of Debt Balance (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
Face value	$ 50,000	$ 50,000
Less: discount	(12,748)	(13,206)
Total	37,252	36,794
Long-term portion	$ 37,252	$ 36,794

Debt - Additional Information (

Debt - Additional Information (Details) - USD ($)		1 Months Ended	3 Months Ended
	Oct. 13, 2022	Sep. 30, 2019	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	May 31, 2017
Debt Instrument [Line Items]
Loan and security agreement, amount			$ 50,000,000		$ 50,000,000
Exercise price per share			$ 0.001
Fair market value per share of common stock			$ 4.60	$ 2.93
Unamortized debt discount			$ (12,748,000)		$ (13,206,000)
Minimum
Debt Instrument [Line Items]
Expected life			5 years 7 months 6 days	5 years 7 months 6 days
Maximum
Debt Instrument [Line Items]
Expected life			7 years	6 years 8 months 12 days
SLR Investment Corp. and Silicon Valley Bank | 2017 Loan Agreement
Debt Instrument [Line Items]
Loan and security agreement, amount						$ 10,000,000
SLR Investment Corp. and Silicon Valley Bank | 2019 Loan Agreement
Debt Instrument [Line Items]
Loan and security agreement, amount		$ 20,000,000	$ 50,000,000
Loan agreement, maturity date		Sep. 17, 2023
Amortization of debt discount				$ 87,000
Final payment fee			$ 500,000
Amortization of final payment fee				$ 34,000
Debt instrument, interest rate terms			The interest rate under the 2019 Loan Agreement was the higher of (i) LIBOR plus 7.95% or (ii) 10.18%
Debt instrument, effective interest rate					10.18%
Exit fee, percentage			4%
Exit fee			$ 800,000
Prepayment premium percentage after year two			0.50%
Increase in interest rate on default			5%
Long term debt prepayment premium amount			$ 46,000
SLR Investment Corp. and Silicon Valley Bank | 2019 Loan Agreement | Minimum
Debt Instrument [Line Items]
Interest rate, minimum			10.18%
Prepayment premium percentage two			0.01
SLR Investment Corp. and Silicon Valley Bank | 2019 Loan Agreement | Maximum
Debt Instrument [Line Items]
Prepayment premium percentage one			0.03
SLR Investment Corp. and Silicon Valley Bank | 2019 Loan Agreement | Libor
Debt Instrument [Line Items]
Basis spread on variable base rate			7.95%
Oaktree Agreement [Member]
Debt Instrument [Line Items]
Loan agreement, maturity date	Oct. 13, 2027
Basis spread on variable base rate	8.25%
Proceeds from (Repayments of) Debt, Total	$ 9,800,000
Payment of Financing and Stock Issuance Costs	2,700,000
Long term additional debt discount exit fee			$ 1,000,000
Embedded derivative liability upon issuance of Term Loan	8,900,000
Fair value of embedded derivative liability			6,500,000
Amortization of debt discount			459,000
Unamortized debt discount	$ (13,600,000)
Exit fee			$ 34,000,000
Prepayment premium percentage one	0.020
Increase in interest rate on default	2%
Oaktree Agreement [Member] | Minimum
Debt Instrument [Line Items]
Trailing of net sales	$ 100,000,000
Oaktree Agreement [Member] | Maximum
Debt Instrument [Line Items]
Loan and security agreement, amount	$ 100,000,000
Oaktree Agreement [Member] | Warrants
Debt Instrument [Line Items]
Exercise price per share	$ 5.40
Relative fair value of detachable warrants	$ 2,000,000
Risk-free rate	4.11%
Expected life	7 years
Fair market value per share of common stock	$ 5.50
Exercise price per warrant	$ 5.40
Expected volatility	77%
Oaktree Agreement [Member] | Warrants | Maximum
Debt Instrument [Line Items]
Purchase shares of common stock	516,345
Oaktree Agreement [Member] | SOFR
Debt Instrument [Line Items]
Basis spread on variable base rate	8.75%
Oaktree Agreement [Member] | SOFR | Interest Rate Floor [Member]
Debt Instrument [Line Items]
Basis spread on variable base rate	1%
Oaktree Agreement [Member] | SOFR | Interest Rate Cap [Member]
Debt Instrument [Line Items]
Basis spread on variable base rate	3%
Oaktree Agreement [Member] | Borrowings One [Member]
Debt Instrument [Line Items]
Loan and security agreement, amount	$ 50,000,000
Proceeds from term loan	37,500,000
Unrestricted cash	15,000,000
Oaktree Agreement [Member] | Borrowings Two [Member]
Debt Instrument [Line Items]
Loan and security agreement, amount	50,000,000
Unrestricted cash	20,000,000
Oaktree Agreement [Member] | Borrowings Three [Member]
Debt Instrument [Line Items]
Loan and security agreement, amount	$ 50,000,000

Debt - Schedule of Future Princ

Debt - Schedule of Future Principal Payments Due (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2019
Debt Instrument [Line Items]
Total	$ 50,000	$ 50,000
2019 Loan Agreement | SLR Investment Corp. and Silicon Valley Bank
Debt Instrument [Line Items]
December 31, 2025	2,500
December 31, 2026	10,000
December 31, 2027	37,500
Total	$ 50,000		$ 20,000

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($)		3 Months Ended
	Mar. 23, 2021	Mar. 31, 2023
Common Stock
Stockholders Equity Note [Line Items]
Number of shares sold		1,511,157
2021 ATM Agreement
Stockholders Equity Note [Line Items]
Number of shares sold		1,511,157
Selling price per share		$ 9.30
Proceeds from sale of shares,Net		$ 13,700,000
2021 ATM Agreement | Cowen | Common Stock | Maximum
Stockholders Equity Note [Line Items]
Aggregate offering price	$ 50,000,000
Percentage of commission on gross sales proceeds	3%

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ in Millions		3 Months Ended
	Feb. 01, 2023	Mar. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional options granted		652,462
Stock option, number of shares outstanding		4,640,089	4,008,177
Unrecognized compensation expense		$ 5.7
Recognition period (in years)		2 years 8 months 12 days
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense		$ 1.2
Recognition period (in years)		3 years 9 months 18 days
2017 Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option and incentive plan effective date		Nov. 30, 2017
Stock option and incentive plan expiration date		Oct. 31, 2027
Stock option, number of shares outstanding		3,902,928
Number of common shares authorized for issuance		7,475,463
Stock options, available for issuance		3,199,318
Term of option granted		10 years
2017 Stock Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Term of option granted		1 year
2017 Stock Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Term of option granted		4 years
2017 Stock Plan | Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of restricted stock units outstanding		333,125
2014 Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional options granted		0
Stock option and incentive plan expiration date		Nov. 30, 2017
Stock option, number of shares outstanding		598,411
Number of options forfeited		359,860
2017 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock shares available for issuance		1,347,691
2023 Employment Inducement Award Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option, number of shares outstanding		138,750
Stock options, available for issuance		361,250
Equity awards granted under the inducement , Granted	500,000
Term of option granted		10 years

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Estimated Fair Value of Options Valuation Assumptions (Details) - $ / shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, minimum	3.40%	1.67%
Risk-free interest rate, maximum	4.17%	1.90%
Expected dividend yield	0%	0%
Expected volatility, minimum	77%	70%
Expected volatility, maximum	85%	72%
Weighted-average grant date fair value	$ 4.60	$ 2.93
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life	5 years 7 months 6 days	5 years 7 months 6 days
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life	7 years	6 years 8 months 12 days

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Information about Stock Option Activity (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) $ / shares shares
NUMBER OF SHARES
Number of shares outstanding, beginning balance | shares	4,008,177
Additional options granted | shares	652,462
Number of shares forfeited | shares	(20,550)
Number of shares outstanding, ending balance | shares	4,640,089
Vested and exercisable, ending balance | shares	2,283,867
Vested and expected to vest, ending balance | shares	4,014,732
WEIGHTED-AVERAGE EXERCISE PRICE
Weighted average exercise prices, outstanding beginning balance | $ / shares	$ 5.76
Weighted average exercise prices, granted | $ / shares	6.31
Weighted average exercise prices, forfeited | $ / shares	5.33
Weighted average exercise prices, outstanding ending balance | $ / shares	5.84
Weighted average exercise prices, vested and exercisable ending balance | $ / shares	6.01
Weighted average exercise prices, vested and expected to vest ending balance | $ / shares	$ 5.86
WEIGHTED-AVERAGE REMAINING CONTRACTUAL TERM
Weighted average remaining contractual term, outstanding	7 years 6 months 29 days
Weighted average remaining contractual term, vested and exercisable	6 years 1 month 13 days
Weighted average remaining contractual term, vested and expected to vest	7 years 4 months 2 days
AGGREGATE INTRINSIC VALUE
Aggregate intrinsic value, outstanding ending balance | $	$ 15,792
Aggregate intrinsic value, vested and exercisable ending balance | $	7,774
Aggregate intrinsic value, vested and expected to vest ending balance | $	$ 13,687

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of RSU Activity (Details) - Restricted Stock Units (RSUs)	3 Months Ended
	Mar. 31, 2023 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
RSUs Outstanding, December 31, 2022 | shares	0
RSUs Granted | shares	335,410
RSUs Forfeited | shares	(2,285)
RSUs outstanding at March 31, 2023 | shares	333,125
AVERAGE GRANT DATE FAIR VALUE, Outstanding, December 31, 2022 | $ / shares	$ 0
AVERAGE GRANT DATE FAIR VALUE, Granted | $ / shares	6.14
AVERAGE GRANT DATE FAIR VALUE, Forfeited | $ / shares	6.14
AVERAGE GRANT DATE FAIR VALUE, RSUs outstanding at March 31, 2023 | $ / shares	$ 6.14

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 980	$ 636
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	340	254
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 640	$ 382

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Commitments And Contingencies [Line Items]
Operating leases expire	2025
Short-term lease asset	$ 466,000	$ 566,000
Short-term lease liability	419,000	$ 567,000
Short-term Leases Recognized on Straight-line Basis
Commitments And Contingencies [Line Items]
Short-term lease asset	0
Short-term lease liability	$ 0

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Maturity Analysis of Annual Undiscounted Cash Flows of Operating Lease Liabilities (Details) $ in Thousands	Mar. 31, 2023 USD ($)
Year ended:
December 31, 2023	$ 433
December 31, 2024	9
December 31, 2025	1
Total minimum lease payments	443
Less imputed interest	(19)
Total	$ 424

Commitments and Contingencies_3

Commitments and Contingencies - Schedule of Lease Cost and Other Information of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Lease cost:
Operating lease cost	$ 112	$ 118
Short-term lease cost	9	13
Sublease income		(13)
Total lease cost	121	118
Other information
Cash paid for amounts included in the measurement of lease liabilities	163	140
Operating cash flows from operating leases	$ (50)	$ (18)
Weighted-average remaining lease term - operating leases	8 months 12 days	9 months 18 days
Weighted-average discount rate - operating leases	10.10%	10.10%