Delcath Systems (DCTH) 10-Q 14 May 24 2024 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2024	May 09, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-16133
Entity Registrant Name	DELCATH SYSTEMS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	06-1245881
Entity Address, Address Line One	566 Queensbury Avenue
Entity Address, City or Town	Queensbury
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	12804
City Area Code	212
Local Phone Number	489-2100
Title of 12(b) Security	Common stock, $0.01 par value per share
Trading Symbol	DCTH
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		27,785,803
Entity Central Index Key	0000872912
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets
Cash and cash equivalents	$ 11,760	$ 12,646
Restricted cash	50	50
Short-term investments	15,360	19,808
Accounts receivable, net	1,564	241
Inventory	3,634	3,322
Prepaid expenses and other current assets	1,278	1,091
Total current assets	33,646	37,158
Property, plant and equipment, net	1,336	1,352
Right-of-use assets	1,117	103
Total assets	36,099	38,613
Current liabilities
Accounts payable	1,487	1,012
Accrued expenses	4,395	5,249
Lease liabilities, current	102	37
Loan payable	2,408	5,239
Convertible notes payable	4,949	4,911
Total current liabilities	13,341	16,448
Warrant liability	6,160	5,548
Lease Liabilities, non-current	1,016	0
Other liabilities, non-current	962	840
Total liabilities	21,479	22,836
Commitments and contingencies (see Note 15)
Stockholders’ equity
Preferred stock, $0.01 par value; 10,000,000 shares authorized; 16,809 and 24,819 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively	0	0
Common stock, $0.01 par value; 80,000,000 shares authorized; 25,439,319 shares and 22,761,554 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively	254	228
Additional paid-in capital	530,482	520,576
Accumulated deficit	(516,273)	(505,162)
Accumulated other comprehensive loss	157	135
Total stockholders’ equity	14,620	15,777
Total liabilities and stockholders’ equity	$ 36,099	$ 38,613

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	16,809	24,819
Preferred stock, shares outstanding (in shares)	16,809	24,819
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	80,000,000	80,000,000
Common stock, shares issued (in shares)	25,439,319	22,761,554
Common stock, shares outstanding (in shares)	25,439,319	22,761,554

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Statement [Abstract]
Product revenue	$ 3,139	$ 597
Other revenue	0	0
Total revenues	3,139	597
Cost of goods sold	(903)	(181)
Gross profit	2,236	416
Operating expenses:
Research and development expenses	3,700	4,576
Selling, general and administrative expenses	8,814	4,165
Total operating expenses	12,514	8,741
Operating loss	(10,278)	(8,325)
Change in fair value of warrant liability	(612)	0
Interest expense, net	(199)	(688)
Other (expense) income	(22)	13
Net loss	(11,111)	(9,000)
Other comprehensive (loss) income:
Unrealized gain on investments	8	0
Foreign currency translation adjustments	14	19
Total comprehensive loss	$ (11,089)	$ (8,981)
Common share data:
Basic loss per common share (in dollars per share)	$ (0.45)	$ (0.77)
Diluted loss per common share (in dollars per share)	$ (0.45)	$ (0.77)
Weighted average number of basic shares outstanding (in shares)	24,887,180	11,622,384
Weighted average number of diluted shares outstanding (in shares)	24,887,180	11,622,384

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	Total	Stock options	Employee Stock	Preferred F-3 Stock	Preferred Stock	Preferred Stock Preferred F-3 Stock	Common Stock	Common Stock Preferred F-3 Stock	Additional Paid in Capital	Additional Paid in Capital Stock options	Additional Paid in Capital Employee Stock	Additional Paid in Capital Preferred F-3 Stock	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Beginning Balance (in shares) at Dec. 31, 2022					11,357		10,046,571
Beginning Balance at Dec. 31, 2022	$ (5,859)				$ 0		$ 100		$ 451,607				$ (457,483)	$ (83)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation expense for issuance of stock options		$ 1,661								$ 1,661
Private placement -issuance of common shares, net of expenses (in shares)							19,646
Private placement -issuance of common shares, net of expenses	56						$ 1		55
Issuance of common stock with the employee stock purchase plan (in shares)							15,417
Issuance of common stock with the employee stock purchase plan	47								47
Net loss	(9,000)												(9,000)
Foreign currency translation adjustments	19													19
Ending Balance (in shares) at Mar. 31, 2023					11,357		10,081,634
Ending Balance at Mar. 31, 2023	(13,076)				$ 0		$ 101		453,370				(466,483)	(64)
Beginning Balance (in shares) at Dec. 31, 2023					24,819		22,761,554
Beginning Balance at Dec. 31, 2023	15,777				$ 0		$ 228		520,576				(505,162)	135
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation expense for issuance of stock options		$ 2,895	$ 50							$ 2,895	$ 50
Private placement -issuance of common shares, net of expenses (in shares)							876,627
Private placement -issuance of common shares, net of expenses	6,912						$ 8		6,904
Issuance of common stock with the employee stock purchase plan (in shares)							21,140
Issuance of common stock with the employee stock purchase plan	74								74
Conversion of shares (in shares)						(8,010)		1,779,998
Conversion of shares				$ 1				$ 18				$ (17)
Net loss	(11,111)												(11,111)
Unrealized gain on investments	8													8
Foreign currency translation adjustments	14													14
Ending Balance (in shares) at Mar. 31, 2024					16,809		25,439,319
Ending Balance at Mar. 31, 2024	$ 14,620				$ 0		$ 254		$ 530,482				$ (516,273)	$ 157

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity (Deficit) (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Statement of Stockholders' Equity [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net loss	$ (11,111)	$ (9,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock option compensation expense	2,945	1,661
Depreciation expense	29	30
Warrant liability fair value adjustment	612	0
Non-cash lease expense	13	100
Amortization of debt discount	261	194
Interest expense accrued related to convertible notes	40	27
Amortization of premiums and discounts on marketable securities	(229)	0
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(174)	14
Accounts receivable	(1,323)	(92)
Inventory	(312)	(339)
Accounts payable and accrued expenses	(507)	3,221
Other liabilities, non-current	172	(80)
Deferred revenue	0	0
Net cash used in operating activities	(9,584)	(4,264)
Cash flows from investing activities:
Purchase of investment	(10,327)	0
Maturities of investments	15,000	0
Purchase of property, plant and equipment	(13)	0
Net cash provided by investing activities	4,660	0
Cash flows from financing activities:
Proceeds from private placement	7,000	22,960
Proceeds from the issuance of common stock relating to the employee stock purchase plan	75	47
Repayment of debt	(3,054)	(6,313)
Proceeds from exercise of warrants	0	0
Proceeds from exercise of stock options	0	0
Net cash provided by financing activities	4,021	16,694
Foreign currency effects on cash	17	20
Net (decrease) increase in total cash	(886)	12,450
Total Cash, Cash Equivalents and Restricted Cash:
Beginning of period	12,696	11,822
End of period	11,810	24,272
Cash, Cash Equivalents and Restricted Cash consisted of the following:
Cash and Cash Equivalents	11,760	24,222
Restricted Cash	50	50
Total cash, cash equivalents and restricted cash shown in the statements of cash flows	11,810	24,272
Cash paid during the periods for:
Interest expense	250	491
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Right of use assets obtained in exchange for lease obligations	$ 1,029	$ 0

General

General	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
General	General The unaudited interim condensed consolidated financial statements of Delcath Systems, Inc. (“Delcath” or the “Company”) as of and for the three months ended March 31, 2024 and 2023 should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023 (the “Annual Report”), which was filed with the Securities and Exchange Commission (the “SEC”) on March 26, 2024 and may also be found on the Company’s website (www.delcath.com). In these notes to the interim condensed consolidated financial statements the terms “us”, “we” or “our” refer to Delcath and its consolidated subsidiaries. Description of Business The Company is an interventional oncology company focused on the treatment of primary and cancers metastatic to the liver. The Company’s lead product, the HEPZATO TM KIT (melphalan for Injection/Hepatic Delivery System), a drug/device combination product, was approved by the US Food and Drug Administration (the “FDA”) on August 14, 2023, indicated as a liver-directed treatment for adult patients with uveal melanoma with unresectable hepatic metastases affecting less than 50% of the liver and no extrahepatic disease, or extrahepatic disease limited to the bone, lymph nodes, subcutaneous tissues, or lung that is amenable to resection, or radiation. The first commercial use of HEPZATO KIT (“HEPZATO”) for the treatment of metastatic uveal melanoma (“mUM”) occurred in January 2024. In the United States, HEPZATO is considered a combination drug and device product and is regulated as a drug by the FDA. Primary jurisdiction for regulation of HEPZATO has been assigned to the FDA’s Center for Drug Evaluation and Research. The FDA has granted Delcath six orphan drug designations (five for melphalan in the treatment of patients with ocular (uveal) melanoma, cutaneous melanoma, intrahepatic cholangiocarcinoma, hepatocellular carcinoma, and neuroendocrine tumor indications and one for doxorubicin in the treatment of patients with hepatocellular carcinoma). The Company has sufficient raw material and component constituent parts of HEPZATO KIT to meet the first year of its anticipated demand and it intends to manage supply chain risk through stockpiled inventory and contracting with multiple suppliers for critical components. In Europe, the hepatic delivery system is a stand-alone medical device having the same device components as HEPZATO, but without the melphalan hydrochloride and is approved for sale under the trade name CHEMOSAT Hepatic Delivery System for Melphalan (“CHEMOSAT”), where it has been used at major medical centers to treat a wide range of cancers in the liver. On February 28, 2022, CHEMOSAT received Medical Device Regulation (MDR) certification under the European Medical Devices Regulation (EU) 2017/745, which may be considered by jurisdictions when evaluating reimbursement. To support the New Drug Application for HEPZATO the Company conducted the FOCUS Clinical Trial for Patients with metastatic hepatic dominant Uveal Melanoma (the “FOCUS Trial”), a global registration clinical trial that investigated objective response rate in patients with mUM. The current focus of the Company’s clinical development program is to generate clinical data for CHEMOSAT and HEPZATO either as monotherapy or in combination with immunotherapy. The Company expects that this will support increased clinical adoption of and reimbursement for CHEMOSAT in Europe, and to support reimbursement in various jurisdictions, including the United States. In addition to HEPZATO’s use to treat mUM, the Company believes that HEPZATO has the potential to treat cancers in the liver, such as metastatic colorectal cancer, metastatic neuroendocrine tumors, metastatic breast cancer and intrahepatic cholangiocarcinoma, and plans to begin one or more studies of HEPZATO KIT to treat such conditions in 2024. The Company believes that those and similar disease states are areas of unmet medical needs that represent significant market opportunities. Risks and Uncertainties As detailed in the Company’s 2023 Annual Report filed on Form 10-K, the Company is subject to risks common to companies in the biopharmaceutical industry with FDA-approved products and planned clinical development activities, including, but not limited to, risks associated with successfully launching and commercializing the products; further developing HEPZATO to potentially treat other cancers in the liver and the Company’s ability to obtain any additional regulatory approval of such produ cts in the United States and obtaining regulatory approval in other geographic markets; the uncertainty relating to the broad adoption of any approved products by physicians and consumers; and the impacts of significant competition. In addition, high rates of inflation have resulted in the U.S. Federal Reserve raising interest rates. Increases in interest rates, especially if coupled with reduced government spending and volatility in financial markets, may further increase economic uncertainty and heighten these risks. Furthermore, if additional banks and financial institutions enter receivership or become insolvent in the future in response to financial conditions affecting the banking system and financial markets, the Company or its partners’ ability to access existing cash, cash equivalents and investments may be threatened and could have a material adverse effect on the Company’s business and financial condition, including the Company’s ability to access additional capital on favorable terms, or at all, which could in the future negatively affect the Company’s ability to pursue its business strategy. Liquidity and Going Concern On March 31, 2024, the Company had cash, cash equivalents and restricted cash totaling $11.8 million and short-term investments totaling $15.4 million, as compared to cash, cash equivalents and restricted cash totaling $12.7 million and short-term investments totaling $19.8 million at December 31, 2023. During the three months ended March 31, 2024, the Company used $9.6 million of cash in its operating activities and $3.1 million for principal payments. The Company’s future results are subject to substantial risks and uncertainties. The Company has operated at a loss for its entire history and there can be no assurance that it will ever achieve or maintain profitability. The Company has historically funded its operations primarily with proceeds from sales of common stock, warrants and pre-funded warrants for the purchase of common stock, sales of preferred stock, proceeds from the issuance of convertible debt and borrowings under loan and security agreements. If there is a substantial delay in the activation of sites to administer HEPZATO, the Company expects to need to raise additional capital under structures available to the Company, including debt and/or equity offerings, which may not be on favorable terms. In a substantially delayed site activation scenario, the Company would not have sufficient funds to meet its obligations within twelve months from the issuance date of these condensed consolidated financial statements. As such, there is uncertainty regarding the Company’s ability to maintain liquidity sufficient to operate its business effectively, which raises substantial doubt about the Company’s ability to continue as a going concern. Debt financing and equity financing, if available, may involve agreements that include covenants limiting or restricting the Company’s ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. If the Company raises funds through collaborations or other similar arrangements with third parties, it may have to relinquish valuable rights to its technologies, future revenue streams, research programs for product candidates and/or grant licenses on terms that may not be favorable to the Company, any of which may reduce the value of its common stock. If the Company is unable to raise additional funds through equity or debt financings when needed, it may be required to delay, limit, reduce or terminate its product development or future commercialization efforts or grant rights to develop and market its product candidates to third parties even if the Company would otherwise prefer to develop and market such product candidates itself. The Company also expects to use cash and cash equivalents to fund activities relating to commercial support for HEPZATO, CHEMOSAT and any future clinical research trials and operating activities. The Company’s future liquidity and capital requirements will depend on numerous factors, including the initiation and progress of clinical trials and research and product development programs; obtaining regulatory approvals and complying with applicable laws and regulations; the timing and effectiveness of product commercialization activities, including marketing arrangements; the timing and costs involved in preparing, filing, prosecuting, defending and enforcing intellectual property rights; the resolution of any disputes with third parties; and the effect of competing technological and market developments. The Company’s capital commitments over the next twelve months include (a) $6.0 million to satisfy accounts payable, accrued expenses, current lease liabilities and current medac settlement and (b) $7.6 million of loan and convertible note principal payments, if the holders do not elect to convert up to $5.0 million of the notes into equity. Additional capital commitments beyond the next twelve months include (a) $1.0 million of lease liabilities; and (b) $0.8 million for settlement of litigation with medac. Basis of Presentation These interim condensed consolidated financial statements are unaudited and were prepared by the Company in accordance with generally accepted accounting principles in the United States of America (GAAP) and with the SEC’s instructions to Form 10-Q and Article 10 of Regulation S-X. They include the accounts of all wholly owned subsidiaries and all significant inter-company accounts and transactions have been eliminated in consolidation. The preparation of interim condensed consolidated financial statements requires management to make assumptions and estimates that impact the amounts reported. These interim condensed consolidated financial statements reflect all adjustments, consisting of normal recurring accruals, necessary for a fair presentation of the Company’s results of operations, financial position and cash flows for the interim periods ended March 31, 2024 and 2023; however, certain information and footnote disclosures normally included in our audited consolidated financial statements which were included in our Annual Report have been condensed or omitted as permitted by GAAP. It is important to note that the Company’s results of operations and cash flows for interim periods are not necessarily indicative of the results of operations and cash flows to be expected for a full fiscal year or any interim period. Significant Accounting Policies There have been no material changes to our significant accounting policies as set forth in Note 3 Summary of Significant Accounting Policies to the consolidated financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023. Recent Accounting Pronouncements No new accounting standards were adopted during the three months ended March 31, 2024

Revenue

Revenue	3 Months Ended
	Mar. 31, 2024
Revenue from Contract with Customer [Abstract]
Revenue	Revenue The Company recognizes product revenue from sales of HEPZATO in the United States and CHEMOSAT in certain European countries in accordance with the five-step model in Accounting Standards Codification (“ASC”) 606, Revenue Recognition: (i) identify 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 revenues when (or as) the Company satisfies the performance obligation. Under this revenue standard, the Company recognizes revenue when its customer obtains control of the promised goods, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods. There are no contractual rights of returns, refunds or similar obligations. HEPZATO The Company ships and sells the HEPZATO directly to hospitals and treating centers based on approved agreements. Prior to use of the HEPZATO, the inventory is considered on consignment in which the Company retains title to the product. The Company recognizes HEPZATO revenue, based on contracted rates stated in an approved contract or purchase order, upon completion of the procedure as evidenced through the Company’s required Risk Evaluation and Mitigation Strategy (“REMS”) system. There is no obligation for the hospitals or treating centers to use the consigned HEPZATO, and the Company has no contractual right to receive payment until the product is used in a procedure and transfer of control is completed. See Note 5 for further information for consignment inventory. CHEMOSAT CHEMOSAT is sold directly to hospitals in the European Union and United Kingdom based on contracted rates in an approved contract or sales order. The Company recognizes product revenue from sales of CHEMOSAT upon shipment. Revenue by product for the periods indicated were as follows: Three Months Ended March 31, (In thousands) 2024 2023 CHEMOSAT $ 1,131 $ 597 HEPZATO KIT 2,008 — Total revenue $ 3,139 $ 597 Concentration of Credit Risk Potential credit risk exposure for both HEPZATO KIT and CHEMOSAT has been evaluated for the Company’s accounts receivable in accordance with ASC 326, Financial Instruments - Credit Losses. The loss percentage is calculated through the use of current and historical economic and financial information. As of March 31, 2024, there were no estimated losses applied to the accounts receivables balance. The Company’s total percentage of revenue and accounts receivable concentrations from a single customer consisted of the following: For the quarter ended and as of Revenue Accounts Receivable March 31, 2024 52.4 % 46.7 % March 31, 2023 24.2 % 21.8 %

Cash, Cash Equivalents and Rest

Cash, Cash Equivalents and Restricted Cash	3 Months Ended
	Mar. 31, 2024
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash Cash and cash equivalents that are restricted as to withdrawal or use under the terms of certain contractual agreements are recorded in Restricted Cash on the balance sheet. Restricted cash does not include required minimum balances. Cash, cash equivalents, and restricted cash balances were as follows: (In thousands) March 31, December 31, Cash and cash equivalents $ 11,760 $ 12,646 Security for credit cards 50 50 Total cash, cash equivalents and restricted cash shown in the statements of cash flows $ 11,810 $ 12,696

Investments

Investments	3 Months Ended
	Mar. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Investments	Investments Marketable debt securities held by the Company are classified as available-for-sale pursuant to ASC 320, Investments - Debt and Equity Securities, and carried at fair value in the accompanying condensed consolidated balance sheets. The following table summarizes the gross unrealized gains on the Company’s marketable securities as of March 31, 2024: March 31, 2024 Gross Unrealized (In thousands) Amortized Cost Gains Estimated Fair Value U.S. government agency bonds $ 15,195 $ 165 $ 15,360 $ 15,195 $ 165 $ 15,360 Short-term investments $ 15,360 As of March 31, 2024, there was $0.2 million of interest receivable related to the outstanding debt securities held by the Company. The following table summarizes the gross unrealized gains on the Company’s marketable securities as of December 31, 2023: December 31, 2023 Gross Unrealized (in thousands) Amortized Cost Gains Estimated Fair Value U.S. government agency bonds $ 19,651 $ 157 $ 19,808 $ 19,651 $ 157 $ 19,808 Short-term investments $ 19,808

Inventory

Inventory	3 Months Ended
	Mar. 31, 2024
Inventory Disclosure [Abstract]
Inventory	Inventory Inventory consists of the following: (In thousands) March 31, December 31, Raw materials $ 1,335 $ 1,443 Work-in-process 1,983 1,753 Finished goods 316 126 Total inventory $ 3,634 $ 3,322

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	3 Months Ended
	Mar. 31, 2024
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid Expenses and Other Current Assets	Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following: (In thousands) March 31, December 31, Clinical trial expenses $ 222 $ 222 Insurance premiums 173 157 Professional services 332 133 Interest Receivable 164 151 Other 387 428 Total prepaid expenses and other current assets $ 1,278 $ 1,091

Property, Plant, and Equipment

Property, Plant, and Equipment	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment	Property, Plant, and Equipment Property, plant, and equipment consist of the following: (In thousands) March 31, 2024 December 31, 2023 Estimated Useful Life Buildings and land $ 1,318 $ 1,318 30 years - Buildings Enterprise hardware and software 1,857 1,857 3 years Leaseholds 1,779 1,787 Lesser of lease term or estimated useful life Equipment 1,262 1,263 7 years Furniture 215 202 5 years Property, plant and equipment, gross 6,431 6,427 Accumulated depreciation (5,095) (5,075) Property, plant and equipment, net $ 1,336 $ 1,352 Depreciation expense for the three months ended March 31, 2024 and 2023 was less than $0.1 million for each period.

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2024
Payables and Accruals [Abstract]
Accrued Expenses	Accrued Expenses Accrued expenses consist of the following: (In thousands) March 31, December 31, Clinical expenses $ 1,064 $ 1,129 Compensation, excluding taxes 1,567 1,859 Professional fees 252 272 Interest on convertible note 753 713 Inventory 12 585 Other 747 691 Total accrued expenses $ 4,395 $ 5,249

Leases

Leases	3 Months Ended
	Mar. 31, 2024
Leases [Abstract]
Leases	Leases The Company recognizes right-of-use (“ROU”) assets and lease liabilities when it obtains the right to control an asset under a leasing arrangement with an initial term greater than twelve months. The Company leases its facilities under non-cancellable operating and financing leases. The Company evaluates the nature of each lease at the inception of an arrangement to determine whether it is an operating or financing lease and recognizes the ROU asset and lease liabilities based on the present value of future minimum lease payments over the expected lease term. The Company’s leases do not generally contain an implicit interest rate and therefore the Company uses the incremental borrowing rate it would expect to pay to borrow on a similar collateralized basis over a similar term in order to determine the present value of its lease payments. For the three months ended March 31, 2024 and 2023, the Company recognized less than $0.1 million of operating lease expense in the U.S. and less than $0.1 million of operating lease expense in Ireland for the same periods. In 2021, the Company entered into a sub-lease agreement (the “2021 Sub-Lease”) with its previous sub-lessee pursuant to which, effective August 2, 2021, the previous sub-lessee would become the lessee and the Company would then sublease its portion of the premises in Galway, Ireland from the previous sub-lessee. The Company’s annual rent expense under the 2021 Sub-Lease is less than $0.1 million for a term of 5 years . In 2020, the Company entered into an amendment to a sub-lease agreement executed in 2016 for office space at 1633 Broadway, New York, New York. The term of the sub-lease agreement began in April 2016 and, pursuant to amendments, was extended through August 2023. As of August 31, 2023, the lease was month-to-month. No ROU assets or lease liabilities were recognized on the balance sheet as of December 31, 2023 for this arrangement. The Company ended the sublease for its former corporate offices at 1633 Broadway, New York, New York in February 2024. On January 18, 2024, the Company entered into a lease agreement (the “Queensbury Lease”) to lease approximately 18,000 square feet of manufacturing and office space in Queensbury, New York (the “Premises”). The initial term of the lease is five years with a right to extend the lease by an additional five years, exercisable under certain conditions set forth in the Queensbury Lease. The Company’s annual rent expense under the Queensbury Lease is less than $0.2 million for a term of 5 years . The following table summarizes the Company’s operating leases as of March 31, 2024: (In thousands) U.S. Ireland Total Operating cash flows for operating leases $ 4 $ 9 $ 13 Weighted average remaining lease term 9.8 2.3 Weighted average discount rate - operating leases 8 % 8 % Remaining maturities of the Company’s operating leases, excluding short-term leases, are as follows: (In thousands) U.S. Ireland Total Year ended December 31, 2024 $ 108 $ 32 $ 140 Year ended December 31, 2025 144 43 187 Year ended December 31, 2026 144 25 169 Year ended December 31, 2027 148 — 148 Year ended December 31, 2028 153 — 153 Thereafter 800 — 800 Total 1,497 100 1,597 Less present value discount (471) (8) (479) Operating lease liabilities included in the condensed consolidated balance sheets at March 31, 2024 $ 1,026 $ 92 $ 1,118
Leases	Leases The Company recognizes right-of-use (“ROU”) assets and lease liabilities when it obtains the right to control an asset under a leasing arrangement with an initial term greater than twelve months. The Company leases its facilities under non-cancellable operating and financing leases. The Company evaluates the nature of each lease at the inception of an arrangement to determine whether it is an operating or financing lease and recognizes the ROU asset and lease liabilities based on the present value of future minimum lease payments over the expected lease term. The Company’s leases do not generally contain an implicit interest rate and therefore the Company uses the incremental borrowing rate it would expect to pay to borrow on a similar collateralized basis over a similar term in order to determine the present value of its lease payments. For the three months ended March 31, 2024 and 2023, the Company recognized less than $0.1 million of operating lease expense in the U.S. and less than $0.1 million of operating lease expense in Ireland for the same periods. In 2021, the Company entered into a sub-lease agreement (the “2021 Sub-Lease”) with its previous sub-lessee pursuant to which, effective August 2, 2021, the previous sub-lessee would become the lessee and the Company would then sublease its portion of the premises in Galway, Ireland from the previous sub-lessee. The Company’s annual rent expense under the 2021 Sub-Lease is less than $0.1 million for a term of 5 years . In 2020, the Company entered into an amendment to a sub-lease agreement executed in 2016 for office space at 1633 Broadway, New York, New York. The term of the sub-lease agreement began in April 2016 and, pursuant to amendments, was extended through August 2023. As of August 31, 2023, the lease was month-to-month. No ROU assets or lease liabilities were recognized on the balance sheet as of December 31, 2023 for this arrangement. The Company ended the sublease for its former corporate offices at 1633 Broadway, New York, New York in February 2024. On January 18, 2024, the Company entered into a lease agreement (the “Queensbury Lease”) to lease approximately 18,000 square feet of manufacturing and office space in Queensbury, New York (the “Premises”). The initial term of the lease is five years with a right to extend the lease by an additional five years, exercisable under certain conditions set forth in the Queensbury Lease. The Company’s annual rent expense under the Queensbury Lease is less than $0.2 million for a term of 5 years . The following table summarizes the Company’s operating leases as of March 31, 2024: (In thousands) U.S. Ireland Total Operating cash flows for operating leases $ 4 $ 9 $ 13 Weighted average remaining lease term 9.8 2.3 Weighted average discount rate - operating leases 8 % 8 % Remaining maturities of the Company’s operating leases, excluding short-term leases, are as follows: (In thousands) U.S. Ireland Total Year ended December 31, 2024 $ 108 $ 32 $ 140 Year ended December 31, 2025 144 43 187 Year ended December 31, 2026 144 25 169 Year ended December 31, 2027 148 — 148 Year ended December 31, 2028 153 — 153 Thereafter 800 — 800 Total 1,497 100 1,597 Less present value discount (471) (8) (479) Operating lease liabilities included in the condensed consolidated balance sheets at March 31, 2024 $ 1,026 $ 92 $ 1,118

Loans and Convertible Notes Pay

Loans and Convertible Notes Payable	3 Months Ended
	Mar. 31, 2024
Debt Disclosure [Abstract]
Loans and Convertible Notes Payable	Loans and Convertible Notes Payable March 31, 2024 December 31, 2023 (In thousands) Gross Discount Net Gross Discount Net Loans payable, current 1 $ 2,557 $ (149) $ 2,408 $ 5,610 $ (371) $ 5,239 Convertible notes payable - current 5,000 (51) 4,949 5,000 (89) 4,911 Total - Loans and notes payable $ 7,557 $ (200) $ 7,357 $ 10,610 $ (460) $ 10,150 1 The gross amount includes the 4.25% final payment of $0.5 million. Term Loan from Avenue Venture Opportunities Fund, L.P. On August 6, 2021, the Company entered into a Loan and Security Agreement (the “Avenue Loan Agreement”) with Avenue Venture Opportunities Fund, L.P. (the “Lender,” or “Avenue”) for a term loan in an aggregate principal amount of up to $20.0 million (the “Avenue Loan”). The Avenue Loan bears interest at an annual rate equal to the greater of (a) the sum of 7.70% plus the prime rate as reported in The Wall Street Journal and (b) 10.95%. The interest rate at March 31, 2024 was 16.20%. The Avenue Loan is secured by all of the Company’s assets globally, including intellectual property. The Avenue Loan matures on August 1, 2024. The initial tranche of the Avenue Loan was $15.0 million, including $4.0 million that was funded into a restricted account. On March 15, 2023, the Company returned to Avenue $4.0 million held as restricted cash to pay down a portion of the outstanding loan balance, principal payments of $2.1 million and an incremental 4.25% of the final payment of $0.2 million. On March 31, 2023, the Avenue Loan Agreement was amended (the “Avenue Amendment”) to defer the interest only period to September 30, 2023, with an additional extension option upon FDA Approval for the HEPZATO KIT and subsequent receipt of at least $10 million from the sale and issuance of equity securities. On August 14, 2023, the Company received FDA approval and has subsequently received over $10 million from the exercise of Tranche A Preferred Warrants. At the Company’s option, it elected to extend the interest only period to December 31, 2023 and monthly principal payments of approximately $1.0 million began in January 2024. Up to $3.0 million of the principal amount of the Avenue Loan outstanding may be converted, at Avenue’s option, into shares of the Company’s common stock at a conversion price of $11.98 per share. The Avenue Loan Agreement requires the Company to make and maintain representations and warranties and other agreements that are customary in loan agreements of this type. The Avenue Loan Agreement also contains customary events of default, including non-payment of principal or interest, violations of covenants, bankruptcy and material judgements. In connection with the initial entry into the Avenue Loan Agreement, the Company issued warrants to Avenue (the “Initial Avenue Warrant”) to purchase 127,755 shares of common stock at an exercise price per share equal to $0.01. Additionally, in connection with the Avenue Amendment, the Company issued to Avenue a warrant to purchase 34,072 shares of common stock at an exercise price per share equal to $0.01. Both the Initial Avenue Warrant and the warrant to purchase 34,072 shares of common stock were exercised in full in April 2024. The Company determined that the embedded conversion option associated with the Avenue Loan did not require bifurcation and met the criteria for equity classification. In addition, the amendment was recorded under debt modification guidance. Aggregate debt discount amortization of $0.3 million and $0.2 million was recorded during the three months ended March 31, 2024 and 2023, respectively. Interest expense incurred was $0.3 million and $0.5 million for the three months ended March 31, 2024 and 2023, respectively. Convertible Notes Payable The Company has $2.0 million of principal outstanding related to Senior Secured Promissory Notes (the “Rosalind Notes”) which bear interest at 8% per annum. Pursuant to the original terms, the Rosalind Notes were convertible into Series E Preferred Stock at a price of $1,500 per share and were to mature on July 16, 2021. On August 6, 2021, the Company executed an agreement to amend the Rosalind Notes to (i) reduce the conversion price to $1,198 per share of the Company’s Series E Preferred Stock; and (ii) extend the maturity date to October 30, 2024. In addition, the holders of the Rosalind Notes agreed to subordinate all of the Company’s indebtedness and obligations to Avenue and all of the holders’ security interest to the Avenue Loan and Avenue’s security interest in the Company’s property. Interest expense accrued relating to the Rosalind Notes was less than $0.1 million for both the three months ended March 31, 2024 and 2023.

Preferred Purchase Agreement

Preferred Purchase Agreement	3 Months Ended
	Mar. 31, 2024
Preferred Purchase Agreement [Abstract]
Preferred Purchase Agreement	Preferred Purchase Agreement On March 27, 2023, we entered into a securities purchase agreement with certain accredited investors (the “Preferred Purchase Agreement”), pursuant to which on March 29, 2023, the Company issued and sold, in a private placement (the “Series F Preferred Offering”), (i) 24,900 shares of Series F-1 Convertible Preferred Stock, par value $0.01 per share (the “Series F-1 Preferred Stock”), (ii) tranche A warrants (the “Preferred Tranche A Warrants”) to acquire 34,859 shares of Series F-3 Convertible Preferred Stock, par value $0.01 per share (the “Series F-3 Preferred Stock”) and (iii) tranche B warrants (the “Preferred Tranche B Warrants”, together with the Preferred Tranche A Warrant, the “Preferred Warrants”) to acquire 24,900 shares of Series F-4 Convertible Preferred Stock, par value $0.01 per share (the “Series F-4 Preferred Stock”) for an aggregate offering price of $24.9 million before deducting the fees paid to the placement agent and the financial advisors and other financing expenses payable by the Company. The gross proceeds of $24.9 million from the Series F Preferred Offering have been allocated first to the Preferred Warrant liabilities at their fair value of $4.9 million, with the residual of $20.0 million being allocated to the Series F-1 Preferred Stock. As of March 31, 2024, all of the Preferred Tranche A Warrants were exercised for an aggregate exercise price of $34.9 million. The Preferred Tranche B Warrants are exercisable for 24,900 shares of Series F-4 Preferred Stock, with an aggregate exercise price of $24.9 million until the earlier of (i) 21 days following the Company’s announcement of receipt of at least $10 million in quarterly U.S. revenue from the commercialization of HEPZATO and (ii) March 31, 2026. Pursuant to the Certificate of Designation of Preferences, Rights and Limitations of the Series F Convertible Voting Preferred Stock (the “Certificate of Designation”), each share of Series F-1 Preferred Stock automatically converted into shares of common stock and/or, if applicable (in accordance with the beneficial ownership limitations then in effect), shares of Series F-2 Preferred Stock, par value $0.01 per share (the “Series F-2 Preferred Stock” and, together with the Series F-1 Preferred Stock, the Series F-3 Preferred Stock and the Series F-4 Preferred Stock, the “Series F Preferred Stock”) in lieu of common stock. Subject to limitations set forth in the Certificate of Designation, the shares of Series F-2, F-3 and F-4 Preferred Stock are convertible into common stock at the option of the holder at the conversion price of $3.30 per share, $4.50 per share and $6.00 per share, respectively, rounded down to the nearest whole share, and in each case subject to the terms and limitations contained in the Certificate of Designation. As of March 31, 2024, 54,207 shares of the Company’s Series F-1, F-2 and F-3 Preferred Stock were converted into 13,853,143 shares of common stock. As of March 31, 2024, there were 2,542 shares of Series F-2 Preferred Stock, 3,010 shares of Series F-3 Preferred Stock and no shares of Series F-4 Preferred Stock outstanding. The Series F-2, F-3 and F-4 Preferred Stock are not mandatorily redeemable, redeemable at the holder’s election or contingently redeemable at the holder’s election (at this point, a Deemed Liquidation Event would potentially trigger pro rata liquidation payments to the preferred and common stockholders on a pro rata “as converted” basis). Accordingly, the Series F-2, F-3 and F-4 Preferred are now classified as permanent equity.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2024
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders’ Equity Public and Private Placements Common Purchase Agreement On March 27, 2023, the Company entered into a securities purchase agreement (the “Common Purchase Agreement”) with the Company’s Chief Executive Officer, Gerard Michel, pursuant to which the Company agreed to issue and sell, in a private placement (the “Common Offering”) shares of common stock, tranche A warrants (“Common Tranche A Warrants”) to acquire 31,110 shares of common stock, tranche B warrants (“Common Tranche B Warrants”, together with the Common Tranche A Warrants, the “Common Warrants”) to acquire 16,666 shares of common stock. On March 29, 2023, the Company closed the Common Offering. The aggregate exercise price of the Common Tranche A Warrants issued pursuant to the Common Offering is approximately $0.1 million. On August 14, 2023, the Company announced the receipt of the FDA Approval and all Common Tranche A Warrants were exercised and converted into 31,110 shares of common stock. The aggregate exercise price of the Common Tranche B Warrants issued in the Common Offering is approximately $0.1 million. The Common Tranche B Warrants are exercisable for an aggregate of 16,666 shares of common stock until the earlier of 21 days following the Company’s announcement of receipt of recording at least $10 million in quarterly U.S. revenue from the commercialization of HEPZATO and March 31, 2026. Securities Purchase Agreement On March 14, 2024, the Company and certain accredited investors (each an “Investor” and collectively, the “Investors”) entered into a securities purchase agreement (the “Securities Purchase Agreement”) pursuant to which the Company agreed to sell and issue to the Investors in a private placement (the “Private Placement”) (i) an aggregate of 876,627 shares of the Company’s common stock, par value $0.01 per share, at a purchase price of $3.72 per share, and (ii) to certain investors, in lieu of shares of common stock, 1,008,102 pre-funded warrants (the “Pre-Funded Warrants”) at a price per Pre-Funded Warrant of $3.71 (the “Warrant Shares” and together with the Shares, the “Securities”). The Pre-Funded Warrants will have an exercise price of $0.01 per share of common stock, be immediately exercisable and remain exercisable until exercised in full. The Private Placement closed on March 19, 2024. The Company received gross proceeds of approximately $7.0 million, before deducting offering expenses payable by the Company. Registration Rights for Preferred and Common Offerings Pursuant to the Preferred Purchase Agreement and the Common Purchase Agreement (collectively, the “Purchase Agreements”), the Company filed a registration statement on Form S-3 (the “June 2023 Resale Registration Statement”) providing for the resale by the investors party thereto of the common stock issuable upon conversion of the Registrable Shares (as defined in the Purchase Agreements). The June 2023 Resale Registration Statement became effective on June 28, 2023. Pursuant to the Securities Purchase Agreement, the Company filed a registration statement on Form S-3 (the “April 2024 Resale Registration Statement”) providing for the resale of the common stock and common stock issuable upon the exercise of the Pre-Funded Warrants. The April 2024 Resale Registration Statement also provided for the common stock issued upon the exercise of pre-funded warrants to purchase common stock issued by the Company pursuant to the Avenue Amendment. The registration became effective on May 9, 2024. There is no established public trading market for the Series F Preferred Stock, the Preferred Warrants, Common Warrants or the Pre-Funded Warrants and the Company does not intend to list such securities on any national securities exchange or nationally recognized trading system. At-the-Market Offering The Company has entered into a Controlled Equity Offering SM Sales Agreement (“ATM Sales Agreement”), with Cantor Fitzgerald & Co. (the “Sales Agent”), pursuant to which the Company may offer and sell, at its sole discretion through the Sales Agent, shares of common stock having an aggregate offering price of up to $17.0 million. To date, the Company has sold approximately $4.0 million of its common stock, prior to issuance costs, under the ATM Sales Agreement. No sales were made during the three months ended March 31, 2024. Authorized Shares The Company is authorized to issue 80 million shares of common stock, $0.01 par value, and 10 million shares of preferred stock, $0.01 par value. As of March 31, 2024, the Company has designated the following preferred stock: Designated Preferred Shares March 31, 2024 Series A 4,200 Series B 2,360 Series C 590 Series D 10,000 Series E 40,000 Series E-1 12,960 Series F-1 24,900 Series F-2 24,900 Series F-3 34,860 Series F-4 24,900 Total 179,670 Preferred Stock As of March 31, 2024, there were an aggregate of 11,257 shares of Series E and Series E-1, 2,542 Series F-2 and 3,010 Series F-3 Convertible Preferred Stock outstanding, respectively. Omnibus Equity Incentive Plan On September 30, 2020, the Company’s 2020 Omnibus Equity Incentive Plan (the “2020 Plan”) was adopted by the Company’s Board of Directors. On November 23, 2020, the Company’s stockholders approved the 2020 Plan. The 2020 Plan will continue in effect until the tenth anniversary of the date of its adoption by the Board or until earlier terminated by the Board. The 2020 Plan is administered by the Board of Directors or a committee designated by the Board of Directors. The 2020 Plan provides for the grant of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance awards, as well as other stock-based awards or cash awards that are deemed to be consistent with the purposes of the plan to Company employees, directors and consultants. As of March 31, 2024, there have been 5,125,000 shares of common stock reserved under the 2020 Plan, of which 232,566 remained available to be issued. In addition to options granted from the 2020 Plan, the Company also grants employment inducement awards pursuant to Listing Rule 5635(c)(4) of the corporate governance rules of the NASDAQ Stock Market. The inducement grants are intended to provide incentive to certain individuals to enter into employment with the Company. Prior to December 5, 2023, the inducement awards were granted outside of the 2020 Plan, however they are governed in all respects as if they were issued under the 2020 Plan. These grants do not reduce the number of options available for issuance under the 2020 Plan. On December 5, 2023, the Company’s 2023 Inducement Plan (the “2023 Plan”) was adopted by the Company’s Board of Directors. The 2023 Plan is administered by a Compensation Committee of two or more Independent Directors appointed by the Board of Directors and is intended to provide for the grant of non-qualified stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance awards, as well as other stock-based awards or cash awards that are deemed appropriate to incentivize employment with the Company. Awards from the 2023 Plan can only be granted to individuals who have not previously worked for the Company or have not worked for the Company for a bona fide period of time. As of March 31, 2024, there have been 650,000 shares of common stock reserved under the 2023 Plan, of which 372,000 remain available to be granted. Stock Options The following tables include information for all options granted including inducement grants that are granted outside of the 2020 Plan. The Company values stock options using the Black-Scholes option pricing model and used the following assumptions, on a weighted-average basis, during the reporting periods: Three Months Ended March 31, 2024 2023 Expected terms (years) 5.6 5.8 Expected volatility 115.0% 172.8% Risk-free interest rate 4.19% 4.08% Expected dividends 0.00% 0.00% The following is a summary of stock option activity for the three months ended March 31, 2024: Number of Options Weighted Average Weighted Average Grant Date Fair Value Per Share Weighted Average Aggregate Intrinsic Outstanding at January 1, 2024 4,183,232 $ 8.17 $ 7.60 8.3 $ 147 Granted 2,017,596 4.80 3.92 9.7 Exercised — — — — Expired (15,341) 7.16 6.91 Cancelled/Forfeited (146,312) 6.08 5.75 Outstanding at March 31, 2024 6,039,175 $ 7.10 $ 6.42 8.6 $ 433 Exercisable at March 31, 2024 2,569,497 $ 9.47 $ 8.73 7.4 $ 74 Unvested at March 31, 2024 3,469,678 $ 5.34 $ 4.70 9.4 $ 358 The following table summarizes information for stock option shares outstanding and exercisable at March 31, 2024: Options Outstanding Range of Exercise Prices Outstanding Number of Weighted Average Number of Options $2.83 - $51.50 6,038,676 8.6 6,038,676 $51.50+ 499 4.8 499 6,039,175 8.6 6,039,175 The following is a summary of share-based compensation expense in the statement of operations for the three months ended March 31, 2024: Three Months Ended March 31, (In thousands) 2024 2023 Selling, general and administrative $ 2,042 $ 1,118 Research and development 647 417 Cost of goods sold 256 126 Total $ 2,945 $ 1,661 At March 31, 2024, there was $10.3 million of aggregate unrecognized compensation expense related employee and board stock option grants. The cost is expected to be recognized over a weighted average period of 1.2 years. Common Stock Warrants The following is a summary of common stock warrant activity for the three months ended March 31, 2024: Warrants Weighted Average Exercise Price Weighted Average Outstanding at January 1, 2024 4,665,201 $ 7.76 1.6 Warrants issued 1,008,102 0.01 5.0 Warrants exercised — — Outstanding at March 31, 2024 5,673,303 2.0 Exercisable at March 31, 2024 5,673,303 $ 6.39 2.0 The following table presents information related to common stock warrants outstanding at March 31, 2024: Warrants Exercisable Range of Exercise Prices Outstanding Weighted Average Number of Warrants $0.01 2,045,894 4.0 2,045,894 $6.00 16,666 2.0 16,666 $10.00 3,610,743 1.0 3,610,743 5,673,303 2.0 5,673,303 As of March 31, 2024, there were no warrants exercised for common shares. Preferred Stock Warrants The following is a summary of preferred stock warrant activity for the three months ended March 31, 2024: Warrants Weighted Average Exercise Price Weighted Average Outstanding at January 1, 2024 24,900 $ 1,000 2.3 Warrants issued — Warrants exercised — Outstanding at March 31, 2024 24,900 $ 1,000 2.0 Exercisable at March 31, 2024 24,900 $ 1,000 2.0 Employee Stock Purchase Plan

Net Loss per Share

Net Loss per Share	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Net Loss per Share	Net Loss per Share Basic net loss per share is determined by dividing net loss by the weighted average shares of common stock outstanding during the period, without consideration of potentially dilutive securities, except for those shares that are issuable for little or no cash consideration. Diluted net loss per share is determined by dividing net loss by diluted weighted average shares outstanding. Diluted weighted average shares reflects the dilutive effect, if any, of potentially dilutive common shares, such as stock options and warrants calculated using the treasury stock method. In periods with reported net operating losses, all common stock options, convertible preferred shares, and preferred and common warrants are generally deemed anti-dilutive such that basic net loss per share and diluted net loss per share are equal. The following potentially dilutive securities were excluded from the computation of earnings per share as of March 31, 2024 and 2023 because their effects would be anti-dilutive: March 31, 2024 2023 Common stock warrants 3,627,409 3,658,520 Assumed conversion of preferred stock warrants 4,149,994 11,896,667 Assumed conversion of preferred stock 2,564,911 8,681,176 Assumed conversion of convertible notes 488,031 488,031 Stock options 6,039,175 2,894,393 Total 16,869,520 27,618,787 As of March 31, 2024 and 2023, the Company had 2,045,894 and 1,576,620 pre-funded warrants outstanding, respectively. The following table provides a reconciliation of the weighted average shares outstanding calculation for the three months ended March 31, 2024 and 2023: Three months ended March 31, 2024 2023 Weighted average shares issued 23,705,374 10,081,634 Weighted average pre-funded warrants 1,181,806 1,540,750 Weighted average shares outstanding 24,887,180 11,622,384

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes As discussed in “Note 17—Income Taxes” to the notes to the consolidated financial statements contained in the Annual Report, the Company has a valuation allowance against the full amount of its net deferred tax assets. The Company currently provides a valuation allowance against deferred tax assets when it is more likely than not that some portion or all of its deferred tax assets will not be realized. The Company has not recognized any unrecognized tax benefits in its balance sheet. The Company is subject to income tax in the U.S., as well as various state and international jurisdictions. The federal and state tax authorities can generally reduce a net operating loss (but not create taxable income) for a period outside the statute of limitations in order to determine the correct amount of net operating loss which may be allowed as a deduction against income for a period within the statute of limitations. Additional information regarding the statutes of limitations can be found in Note 17 - Income Taxes of the Company’s Annual Report. The Inflation Reduction Act of 2022 included tax legislation that became effective in the first quarter of 2023. Significant legislation for corporate taxpayers includes a corporate alternative minimum tax of 15% for companies with $1 billion or more in average net financial statement profits over the three previous years, as well as a 1% indirect excise tax on the repurchase of shares by a publicly traded company. The Company does not expect this legislation to have an effect on the

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies medac Matter In April 2021, the Company’s wholly owned subsidiary, Delcath Systems Ltd, issued to medac GmbH, a privately held, multi-national pharmaceutical company based in Germany (“medac”), an invoice for a €1 million milestone payment under a License, Supply and Marketing Agreement dated December 10, 2018 (the “medac Agreement”) between medac and the Company. The medac Agreement provided to medac the exclusive right to market and sell CHEMOSAT in certain designated countries for which the Company was entitled to a combination of upfront and success-based milestone payments as well as a fixed transfer price per unit of CHEMOSAT and specified royalties. In response to medac’s subsequent dispute and non-payment of the invoice, on October 12, 2021, the Company notified medac in writing that it was terminating the medac Agreement due to medac’s nonpayment of the €1 million milestone payment, with the effective date of termination of the medac Agreement being April 12, 2022. On December 16, 2021, the Company initiated an arbitration proceeding pursuant to the dispute resolution procedures of the medac Agreement for the non-payment of the invoice. On December 30, 2022, the parties reached a final settlement of the matter and the Company agreed to pay medac either (a) a royalty on sales of CHEMOSAT units over a defined minimum for a period of five years or until a maximum payment has been reached, or (b) a minimum annual payment of $0.2 million in the event the annual royalty payment does not reach the agreed minimum payment amount. The Company has estimated the fair value of the settlement to be $1.0 million as of March 31, 2024 and recorded $0.8 million as other liabilities, non-current and $0.2 million as accrued expenses on the Company’s condensed consolidated balance sheet as of March 31, 2024. Manufacturing and Supply Agreements The Company has a License, Supply and Contract Manufacturing Agreement (the “Supply Agreement”) for the supply of melphalan provided in the HEPZATO KIT. An amendment to the Supply Agreement was entered into on April 22, 2024, and effective as of May 1, 2024, which extends the term of the agreement through December 31, 2028, with an option to renew for successive five-year periods upon the mutual written consent of both parties. Although the Supply Agreement does not contain an annual minimum purchase quantity, the Agreement requires Delcath to order full lots of labeled melphalan vials. As of March 31, 2024, the Company has committed to purchasing $2.25 million of melphalan under this Supply Agreement in 2024.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The table below presents activity within Level 3 of the fair value hierarchy, our liabilities carried at fair value for the three months ended March 31, 2024: Level 3 (In thousands) Contingent Warrants Total Balance at January 1, 2024 $ 996 $ 5,548 $ 6,544 Total change in foreign exchange (22) — (22) Warrant liability fair value adjustment — 612 612 Change due to warrant exercise $ — $ — $ — Balance at March 31, 2024 $ 974 $ 6,160 $ 7,134 Contingent liabilities are re-measured to fair value each reporting period using projected financial targets, discount rates, probabilities of payment, and projected payment dates. Projected contingent payment amounts are discounted back to the current period using a discounted cash flow model. Projected financial targets are based on our most recent internal operational budgets and may take into consideration alternate scenarios that could result in more or less profitability for the respective service line. Increases or decreases in projected financial targets and probabilities of payment may result in significant changes in the fair value measurements. Increases in discount rates and the time to payment may result in lower fair value measurements. Increases or decreases in any of those inputs in isolation may result in a significantly lower or higher fair value measurement. As disclosed in Note 11 and Note 12 of the Company’s consolidated financial statements, the Company allocated part of the proceeds of the Series F Preferred Offering to warrant liability issued in connection with the transaction. The valuations of the warrants were determined using option pricing models. The Company concluded that the Preferred Warrants were not in the scope of Accounting Standards Codification, Distinguishing Liabilities from Equity (ASC 480) since the Preferred Warrants are not mandatorily redeemable; and do not have obligations to issue a variable number of shares of preferred stock. The Company determined the Preferred Warrants met the definition of a derivative in accordance with ASC 815 but were not considered indexed to the Company’s common stock since the warrants require early settlement by repurchasing the preferred warrants for cash in an amount equal to the Black-Scholes value in the event of a Fundamental Transaction at pre-specified volatility of 100% as an input to the Black-Scholes calculation. The Company determined to record the Preferred Warrants at fair value with subsequent changes in fair value recorded in earnings at the end of each reporting period. For the three months ended March 31, 2024, the Company recorded an increase to other expense of $0.6 million related to the change in fair value of the warrant liability. These models use inputs such as the underlying price of the shares issued at the measurement date, volatility, risk free interest rate and expected life of the instrument. The Company has classified the warrants as a long-term liability due to potential provisions relating to the holders’ ability to exercise the warrants beyond twelve months of the reporting date. The fair value of the preferred and common warrants at March 31, 2024 and December 31, 2023 was determined by using option pricing models assuming the following: March 31, 2024 December 31, 2023 Risk free interest rate 4.49% 4.09% Expected term (years) 2.0 2.3 Expected volatility 65% 70% Expected dividends 0.00% 0.00% Additionally, the Company has determined that the warrant liability should be classified within Level 3 of the fair-value hierarchy by evaluating each input for the option pricing models against the fair-value hierarchy criteria and using the lowest level of input as the basis for the fair-value classification as called for in ASC 820. There are six inputs: closing price of the Company’s stock on the day of evaluation; the exercise price of the warrants; the remaining term of the warrants; the volatility of the Company’s stock over that term; annual rate of dividends; and the risk-free rate of return. Of those inputs, the exercise price of the warrants and the remaining term are readily observable in the warrant agreements. The annual rate of dividends is based on the Company’s historical practice of not granting dividends. The closing price of the Company’s stock would fall under Level 1 of the fair-value hierarchy as it is a quoted price in an active market, the risk-free rate of return is a Level 2 input, while the historical volatility is a Level 3 input as defined in ASC 820-10. Since the lowest level input is a Level 3, the Company determined the warrant liability is most appropriately classified within Level 3 of the fair value hierarchy. The following tables present information about the Company’s financial assets and liabilities that have been measured at fair value as of March 31, 2024 and December 31, 2023 and indicate the fair value hierarchy of the valuation inputs utilized to determine such fair value. March 31, 2024 (In thousands) Quoted Prices in Significant Significant Total Assets: Money market funds $ 72 $ — $ — $ 72 U.S. government agency bonds — 15,360 — 15,360 Total Assets $ 72 $ 15,360 $ — $ 15,432 Liabilities: Contingent Liability $ — $ — $ 974 $ 974 Warrant Liabilities — — 6,160 6,160 Total Liabilities $ — $ — $ 7,134 $ 7,134 December 31, 2023 (In thousands) Quoted Prices in Significant Other Observable Inputs (Level 2) Significant Total Assets: Money market funds $ 392 $ — $ — $ 392 U.S. government — 19,808 — 19,808 Total Assets $ 392 $ 19,808 $ — $ 20,200 Liabilities: Contingent Liability $ — $ — $ 996 $ 996 Warrant Liabilities — — 5,548 5,548 Total Liabilities $ — $ — $ 6,544 $ 6,544

General (Policies)

General (Policies)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Risks and Uncertainties	Risks and Uncertainties As detailed in the Company’s 2023 Annual Report filed on Form 10-K, the Company is subject to risks common to companies in the biopharmaceutical industry with FDA-approved products and planned clinical development activities, including, but not limited to, risks associated with successfully launching and commercializing the products; further developing HEPZATO to potentially treat other cancers in the liver and the Company’s ability to obtain any additional regulatory approval of such produ cts in the United States and obtaining regulatory approval in other geographic markets; the uncertainty relating to the broad adoption of any approved products by physicians and consumers; and the impacts of significant competition. In addition, high rates of inflation have resulted in the U.S. Federal Reserve raising interest rates. Increases in interest rates, especially if coupled with reduced government spending and volatility in financial markets, may further increase economic uncertainty and heighten these risks. Furthermore, if additional banks and financial institutions enter receivership or become insolvent in the future in response to financial conditions affecting the banking system and financial markets, the Company or its partners’ ability to access existing cash, cash equivalents and investments may be threatened and could have a material adverse effect on the Company’s business and financial condition, including the Company’s ability to access additional capital on favorable terms, or at all, which could in the future negatively affect the Company’s ability to pursue its business strategy.
Liquidity and Going Concern	Liquidity and Going Concern On March 31, 2024, the Company had cash, cash equivalents and restricted cash totaling $11.8 million and short-term investments totaling $15.4 million, as compared to cash, cash equivalents and restricted cash totaling $12.7 million and short-term investments totaling $19.8 million at December 31, 2023. During the three months ended March 31, 2024, the Company used $9.6 million of cash in its operating activities and $3.1 million for principal payments. The Company’s future results are subject to substantial risks and uncertainties. The Company has operated at a loss for its entire history and there can be no assurance that it will ever achieve or maintain profitability. The Company has historically funded its operations primarily with proceeds from sales of common stock, warrants and pre-funded warrants for the purchase of common stock, sales of preferred stock, proceeds from the issuance of convertible debt and borrowings under loan and security agreements. If there is a substantial delay in the activation of sites to administer HEPZATO, the Company expects to need to raise additional capital under structures available to the Company, including debt and/or equity offerings, which may not be on favorable terms. In a substantially delayed site activation scenario, the Company would not have sufficient funds to meet its obligations within twelve months from the issuance date of these condensed consolidated financial statements. As such, there is uncertainty regarding the Company’s ability to maintain liquidity sufficient to operate its business effectively, which raises substantial doubt about the Company’s ability to continue as a going concern. Debt financing and equity financing, if available, may involve agreements that include covenants limiting or restricting the Company’s ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. If the Company raises funds through collaborations or other similar arrangements with third parties, it may have to relinquish valuable rights to its technologies, future revenue streams, research programs for product candidates and/or grant licenses on terms that may not be favorable to the Company, any of which may reduce the value of its common stock. If the Company is unable to raise additional funds through equity or debt financings when needed, it may be required to delay, limit, reduce or terminate its product development or future commercialization efforts or grant rights to develop and market its product candidates to third parties even if the Company would otherwise prefer to develop and market such product candidates itself. The Company also expects to use cash and cash equivalents to fund activities relating to commercial support for HEPZATO, CHEMOSAT and any future clinical research trials and operating activities. The Company’s future liquidity and capital requirements will depend on numerous factors, including the initiation and progress of clinical trials and research and product development programs; obtaining regulatory approvals and complying with applicable laws and regulations; the timing and effectiveness of product commercialization activities, including marketing arrangements; the timing and costs involved in preparing, filing, prosecuting, defending and enforcing intellectual property rights; the resolution of any disputes with third parties; and the effect of competing technological and market developments.
Basis of Presentation	Basis of Presentation These interim condensed consolidated financial statements are unaudited and were prepared by the Company in accordance with generally accepted accounting principles in the United States of America (GAAP) and with the SEC’s instructions to Form 10-Q and Article 10 of Regulation S-X. They include the accounts of all wholly owned subsidiaries and all significant inter-company accounts and transactions have been eliminated in consolidation.
Recent Accounting Pronouncements	Recent Accounting Pronouncements No new accounting standards were adopted during the three months ended March 31, 2024

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2024
Revenue from Contract with Customer [Abstract]
Schedule of Revenue by Product	Revenue by product for the periods indicated were as follows: Three Months Ended March 31, (In thousands) 2024 2023 CHEMOSAT $ 1,131 $ 597 HEPZATO KIT 2,008 — Total revenue $ 3,139 $ 597
Schedule of Revenue and Accounts Receivable Concentrations	The Company’s total percentage of revenue and accounts receivable concentrations from a single customer consisted of the following: For the quarter ended and as of Revenue Accounts Receivable March 31, 2024 52.4 % 46.7 % March 31, 2023 24.2 % 21.8 %

Cash, Cash Equivalents and Re_2

Cash, Cash Equivalents and Restricted Cash (Tables)	3 Months Ended
	Mar. 31, 2024
Cash and Cash Equivalents [Abstract]
Schedule of Cash, Cash Equivalents, and Restricted Cash	Cash, cash equivalents, and restricted cash balances were as follows: (In thousands) March 31, December 31, Cash and cash equivalents $ 11,760 $ 12,646 Security for credit cards 50 50 Total cash, cash equivalents and restricted cash shown in the statements of cash flows $ 11,810 $ 12,696

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Schedule of Unrealized Gains and Losses	The following table summarizes the gross unrealized gains on the Company’s marketable securities as of March 31, 2024: March 31, 2024 Gross Unrealized (In thousands) Amortized Cost Gains Estimated Fair Value U.S. government agency bonds $ 15,195 $ 165 $ 15,360 $ 15,195 $ 165 $ 15,360 Short-term investments $ 15,360 The following table summarizes the gross unrealized gains on the Company’s marketable securities as of December 31, 2023: December 31, 2023 Gross Unrealized (in thousands) Amortized Cost Gains Estimated Fair Value U.S. government agency bonds $ 19,651 $ 157 $ 19,808 $ 19,651 $ 157 $ 19,808 Short-term investments $ 19,808

Inventory (Tables)

Inventory (Tables)	3 Months Ended
	Mar. 31, 2024
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory consists of the following: (In thousands) March 31, December 31, Raw materials $ 1,335 $ 1,443 Work-in-process 1,983 1,753 Finished goods 316 126 Total inventory $ 3,634 $ 3,322

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	3 Months Ended
	Mar. 31, 2024
Prepaid Expense and Other Assets, Current [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following: (In thousands) March 31, December 31, Clinical trial expenses $ 222 $ 222 Insurance premiums 173 157 Professional services 332 133 Interest Receivable 164 151 Other 387 428 Total prepaid expenses and other current assets $ 1,278 $ 1,091

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Components of Property, Plant and Equipment	Property, plant, and equipment consist of the following: (In thousands) March 31, 2024 December 31, 2023 Estimated Useful Life Buildings and land $ 1,318 $ 1,318 30 years - Buildings Enterprise hardware and software 1,857 1,857 3 years Leaseholds 1,779 1,787 Lesser of lease term or estimated useful life Equipment 1,262 1,263 7 years Furniture 215 202 5 years Property, plant and equipment, gross 6,431 6,427 Accumulated depreciation (5,095) (5,075) Property, plant and equipment, net $ 1,336 $ 1,352

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2024
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consist of the following: (In thousands) March 31, December 31, Clinical expenses $ 1,064 $ 1,129 Compensation, excluding taxes 1,567 1,859 Professional fees 252 272 Interest on convertible note 753 713 Inventory 12 585 Other 747 691 Total accrued expenses $ 4,395 $ 5,249

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2024
Leases [Abstract]
Schedule of Lease Costs	The following table summarizes the Company’s operating leases as of March 31, 2024: (In thousands) U.S. Ireland Total Operating cash flows for operating leases $ 4 $ 9 $ 13 Weighted average remaining lease term 9.8 2.3 Weighted average discount rate - operating leases 8 % 8 %
Schedule of Remaining maturity of Operating Leases Excluding Short-Term Leases	Remaining maturities of the Company’s operating leases, excluding short-term leases, are as follows: (In thousands) U.S. Ireland Total Year ended December 31, 2024 $ 108 $ 32 $ 140 Year ended December 31, 2025 144 43 187 Year ended December 31, 2026 144 25 169 Year ended December 31, 2027 148 — 148 Year ended December 31, 2028 153 — 153 Thereafter 800 — 800 Total 1,497 100 1,597 Less present value discount (471) (8) (479) Operating lease liabilities included in the condensed consolidated balance sheets at March 31, 2024 $ 1,026 $ 92 $ 1,118

Loans and Convertible Notes P_2

Loans and Convertible Notes Payable (Tables)	3 Months Ended
	Mar. 31, 2024
Debt Disclosure [Abstract]
Summary of Loans and Convertible Notes Payable	March 31, 2024 December 31, 2023 (In thousands) Gross Discount Net Gross Discount Net Loans payable, current 1 $ 2,557 $ (149) $ 2,408 $ 5,610 $ (371) $ 5,239 Convertible notes payable - current 5,000 (51) 4,949 5,000 (89) 4,911 Total - Loans and notes payable $ 7,557 $ (200) $ 7,357 $ 10,610 $ (460) $ 10,150 1

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2024
Stockholders' Equity Note [Abstract]
Schedule of Designated Preferred Units	As of March 31, 2024, the Company has designated the following preferred stock: Designated Preferred Shares March 31, 2024 Series A 4,200 Series B 2,360 Series C 590 Series D 10,000 Series E 40,000 Series E-1 12,960 Series F-1 24,900 Series F-2 24,900 Series F-3 34,860 Series F-4 24,900 Total 179,670
Summary of Avenue Warrant Valued Using the Black-Scholes Option Pricing Method	The Company values stock options using the Black-Scholes option pricing model and used the following assumptions, on a weighted-average basis, during the reporting periods: Three Months Ended March 31, 2024 2023 Expected terms (years) 5.6 5.8 Expected volatility 115.0% 172.8% Risk-free interest rate 4.19% 4.08% Expected dividends 0.00% 0.00%
Summary of Stock Option Activity	The following is a summary of stock option activity for the three months ended March 31, 2024: Number of Options Weighted Average Weighted Average Grant Date Fair Value Per Share Weighted Average Aggregate Intrinsic Outstanding at January 1, 2024 4,183,232 $ 8.17 $ 7.60 8.3 $ 147 Granted 2,017,596 4.80 3.92 9.7 Exercised — — — — Expired (15,341) 7.16 6.91 Cancelled/Forfeited (146,312) 6.08 5.75 Outstanding at March 31, 2024 6,039,175 $ 7.10 $ 6.42 8.6 $ 433 Exercisable at March 31, 2024 2,569,497 $ 9.47 $ 8.73 7.4 $ 74 Unvested at March 31, 2024 3,469,678 $ 5.34 $ 4.70 9.4 $ 358
Summary of Stock Option Shares Outstanding and Exercisable	The following table summarizes information for stock option shares outstanding and exercisable at March 31, 2024: Options Outstanding Range of Exercise Prices Outstanding Number of Weighted Average Number of Options $2.83 - $51.50 6,038,676 8.6 6,038,676 $51.50+ 499 4.8 499 6,039,175 8.6 6,039,175
Summary of Recognized Share-based Compensation Cost	The following is a summary of share-based compensation expense in the statement of operations for the three months ended March 31, 2024: Three Months Ended March 31, (In thousands) 2024 2023 Selling, general and administrative $ 2,042 $ 1,118 Research and development 647 417 Cost of goods sold 256 126 Total $ 2,945 $ 1,661
Summary of Warrant Activity	The following is a summary of common stock warrant activity for the three months ended March 31, 2024: Warrants Weighted Average Exercise Price Weighted Average Outstanding at January 1, 2024 4,665,201 $ 7.76 1.6 Warrants issued 1,008,102 0.01 5.0 Warrants exercised — — Outstanding at March 31, 2024 5,673,303 2.0 Exercisable at March 31, 2024 5,673,303 $ 6.39 2.0 The following is a summary of preferred stock warrant activity for the three months ended March 31, 2024: Warrants Weighted Average Exercise Price Weighted Average Outstanding at January 1, 2024 24,900 $ 1,000 2.3 Warrants issued — Warrants exercised — Outstanding at March 31, 2024 24,900 $ 1,000 2.0 Exercisable at March 31, 2024 24,900 $ 1,000 2.0
Schedule of Information Related to Stock Warrants Outstanding and Exercisable	The following table presents information related to common stock warrants outstanding at March 31, 2024: Warrants Exercisable Range of Exercise Prices Outstanding Weighted Average Number of Warrants $0.01 2,045,894 4.0 2,045,894 $6.00 16,666 2.0 16,666 $10.00 3,610,743 1.0 3,610,743 5,673,303 2.0 5,673,303

Net Loss per Share (Tables)

Net Loss per Share (Tables)	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Antidilutive Securities Excluded from the Computation of Earnings Per Share	The following potentially dilutive securities were excluded from the computation of earnings per share as of March 31, 2024 and 2023 because their effects would be anti-dilutive: March 31, 2024 2023 Common stock warrants 3,627,409 3,658,520 Assumed conversion of preferred stock warrants 4,149,994 11,896,667 Assumed conversion of preferred stock 2,564,911 8,681,176 Assumed conversion of convertible notes 488,031 488,031 Stock options 6,039,175 2,894,393 Total 16,869,520 27,618,787
Summary of Reconciliation of Weighted Average Shares Outstanding Calculation	The following table provides a reconciliation of the weighted average shares outstanding calculation for the three months ended March 31, 2024 and 2023: Three months ended March 31, 2024 2023 Weighted average shares issued 23,705,374 10,081,634 Weighted average pre-funded warrants 1,181,806 1,540,750 Weighted average shares outstanding 24,887,180 11,622,384

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Schedule of Level 3 Investments	The table below presents activity within Level 3 of the fair value hierarchy, our liabilities carried at fair value for the three months ended March 31, 2024: Level 3 (In thousands) Contingent Warrants Total Balance at January 1, 2024 $ 996 $ 5,548 $ 6,544 Total change in foreign exchange (22) — (22) Warrant liability fair value adjustment — 612 612 Change due to warrant exercise $ — $ — $ — Balance at March 31, 2024 $ 974 $ 6,160 $ 7,134
Schedule of Fair Value Assumptions for Warrants	The fair value of the preferred and common warrants at March 31, 2024 and December 31, 2023 was determined by using option pricing models assuming the following: March 31, 2024 December 31, 2023 Risk free interest rate 4.49% 4.09% Expected term (years) 2.0 2.3 Expected volatility 65% 70% Expected dividends 0.00% 0.00%
Schedule of Financial Assets Carried at Fair Value	The following tables present information about the Company’s financial assets and liabilities that have been measured at fair value as of March 31, 2024 and December 31, 2023 and indicate the fair value hierarchy of the valuation inputs utilized to determine such fair value. March 31, 2024 (In thousands) Quoted Prices in Significant Significant Total Assets: Money market funds $ 72 $ — $ — $ 72 U.S. government agency bonds — 15,360 — 15,360 Total Assets $ 72 $ 15,360 $ — $ 15,432 Liabilities: Contingent Liability $ — $ — $ 974 $ 974 Warrant Liabilities — — 6,160 6,160 Total Liabilities $ — $ — $ 7,134 $ 7,134 December 31, 2023 (In thousands) Quoted Prices in Significant Other Observable Inputs (Level 2) Significant Total Assets: Money market funds $ 392 $ — $ — $ 392 U.S. government — 19,808 — 19,808 Total Assets $ 392 $ 19,808 $ — $ 20,200 Liabilities: Contingent Liability $ — $ — $ 996 $ 996 Warrant Liabilities — — 5,548 5,548 Total Liabilities $ — $ — $ 6,544 $ 6,544

General (Details)

General (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Cash cash equivalents and restricted cash	$ 11,800		$ 12,700
Short-term investments	15,360		$ 19,808
Net cash used in operating activities	9,584	$ 4,264
Principal payments	3,054	$ 6,313
Accounts payable, accrued expenses, current lease liabilities and current medac settlement
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Current capital commitments	6,000
Loan and convertible note principal payments
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Current capital commitments	7,600
Conversion of notes to equity
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Noncurrent capital commitments	5,000
Lease liabilities
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Noncurrent capital commitments	1,000
Settlement of litigation with medac
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Noncurrent capital commitments	$ 800

Revenue - Schedule of Revenue b

Revenue - Schedule of Revenue by Product (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Total revenue	$ 3,139	$ 597
CHEMOSAT
Disaggregation of Revenue [Line Items]
Total revenue	1,131	597
HEPZATO KIT
Disaggregation of Revenue [Line Items]
Total revenue	$ 2,008	$ 0

Revenue - Schedule of Revenue a

Revenue - Schedule of Revenue and Accounts Receivable Concentrations (Details) - Customer Concentration Risk - Single customer	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	52.40%	24.20%
Accounts Receivable
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	46.70%	21.80%

Cash, Cash Equivalents and Re_3

Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 11,760	$ 12,646
Security for credit cards	50	50
Total cash, cash equivalents and restricted cash shown in the statements of cash flows	$ 11,810	$ 12,696	$ 24,272	$ 11,822

Investments (Details)

Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 15,195	$ 19,651
Gross Unrealized Gains	165	157
Estimated Fair Value	15,360	19,808
Interest Receivable	164	151
U.S. government agency bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	15,195	19,651
Gross Unrealized Gains	165	157
Estimated Fair Value	$ 15,360	$ 19,808

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Raw materials	$ 1,335	$ 1,443
Work-in-process	1,983	1,753
Finished goods	316	126
Total inventory	3,634	3,322
Inventory [Line Items]
Finished goods	316	$ 126
Inventory Held at Hospitals and Treatment Centers
Inventory Disclosure [Abstract]
Finished goods	200
Inventory [Line Items]
Finished goods	$ 200

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Prepaid Expense and Other Assets, Current [Abstract]
Clinical trial expenses	$ 222	$ 222
Insurance premiums	173	157
Professional services	332	133
Interest Receivable	164	151
Other	387	428
Total prepaid expenses and other current assets	$ 1,278	$ 1,091

Property, Plant, and Equipmen_2

Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 6,431	$ 6,427
Accumulated depreciation	(5,095)	(5,075)
Property, plant and equipment, net	1,336	1,352
Buildings and land
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 1,318	1,318
Buildings
Property Plant And Equipment [Line Items]
Estimated Useful Life	30 years
Enterprise hardware and software
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 1,857	1,857
Estimated Useful Life	3 years
Leaseholds
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 1,779	1,787
Equipment
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 1,262	1,263
Estimated Useful Life	7 years
Furniture
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 215	$ 202
Estimated Useful Life	5 years

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Payables and Accruals [Abstract]
Clinical expenses	$ 1,064	$ 1,129
Compensation, excluding taxes	1,567	1,859
Professional fees	252	272
Interest on convertible note	753	713
Inventory	12	585
Other	747	691
Total accrued expenses	$ 4,395	$ 5,249

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions		3 Months Ended		12 Months Ended
	Jan. 18, 2024 USD ($) ft²	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2021 USD ($)
Lessee Lease Description [Line Items]
Lease term		12 months
Sub-Lease 2021
Lessee Lease Description [Line Items]
Lease term				5 years
Annual rent expense				$ 0.1
Queensbury Lease
Lessee Lease Description [Line Items]
Lease term	5 years
Annual rent expense	$ 0.2
Area of space | ft²	18,000
Lease term an additional	5 years
U.S.
Lessee Lease Description [Line Items]
Operating lease expense (less than)		$ 0.1	$ 0.1
Ireland
Lessee Lease Description [Line Items]
Operating lease expense (less than)		$ 0.1	$ 0.1

Leases - Summary of Lease Costs

Leases - Summary of Lease Costs (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Other information
Operating cash flows for operating leases	$ 13
U.S.
Other information
Operating cash flows for operating leases	$ 4
Weighted average remaining lease term	9 years 9 months 18 days
Weighted average discount rate - operating leases	8%
Ireland
Other information
Operating cash flows for operating leases	$ 9
Weighted average remaining lease term	2 years 3 months 18 days
Weighted average discount rate - operating leases	8%

Leases - Schedule of Remaining

Leases - Schedule of Remaining Maturity of Operating Leases Excluding Short-Term Leases (Details) $ in Thousands	Mar. 31, 2024 USD ($)
Lessee Lease Description [Line Items]
Year ended December 31, 2024	$ 140
Year ended December 31, 2025	187
Year ended December 31, 2026	169
Year ended December 31, 2027	148
Year ended December 31, 2028	153
Thereafter	800
Total	1,597
Less present value discount	(479)
Operating lease liabilities included in the condensed consolidated balance sheets at March 31, 2024	1,118
U.S.
Lessee Lease Description [Line Items]
Year ended December 31, 2024	108
Year ended December 31, 2025	144
Year ended December 31, 2026	144
Year ended December 31, 2027	148
Year ended December 31, 2028	153
Thereafter	800
Total	1,497
Less present value discount	(471)
Operating lease liabilities included in the condensed consolidated balance sheets at March 31, 2024	1,026
Ireland
Lessee Lease Description [Line Items]
Year ended December 31, 2024	32
Year ended December 31, 2025	43
Year ended December 31, 2026	25
Year ended December 31, 2027	0
Year ended December 31, 2028	0
Thereafter	0
Total	100
Less present value discount	(8)
Operating lease liabilities included in the condensed consolidated balance sheets at March 31, 2024	$ 92

Loans and Convertible Notes P_3

Loans and Convertible Notes Payable - Summary of Loans and Convertible Notes Payable (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Loans and notes payable, gross	$ 7,557	$ 10,610
Discount	(200)	(460)
Total - Loans and notes payable	$ 7,357	10,150
Percentage of final payment included in gross amount	4.25%
Final payment	$ 500
Loans Payable
Debt Instrument [Line Items]
Loans and notes payable, current, gross	2,557	5,610
Discount, current	(149)	(371)
Loans and notes payable, current, net	2,408	5,239
Convertible Notes Payable
Debt Instrument [Line Items]
Loans and notes payable, current, gross	5,000	5,000
Discount, current	(51)	(89)
Loans and notes payable, current, net	$ 4,949	$ 4,911

Loans and Convertible Notes P_4

Loans and Convertible Notes Payable - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands					1 Months Ended		3 Months Ended
	Aug. 14, 2023	Mar. 31, 2023	Mar. 15, 2023	Aug. 06, 2021	Apr. 30, 2024	Jan. 31, 2024	Mar. 31, 2024	Mar. 31, 2023
Debt Instrument [Line Items]
Restricted cash		$ 50					$ 50	$ 50
Principal payments							3,054	6,313
Final payment							500
Proceeds from exercise of warrants							$ 0	$ 0
Warrants issued to purchase of common stock (in shares)				127,755
Warrant exercise price (in dollars per share)		$ 0.01		$ 0.01				$ 0.01
Number of warrants outstanding (in shares)		34,072						34,072
Subsequent Event
Debt Instrument [Line Items]
Warrants exercised (in shares)					34,072
Preferred Tranche A Warrant
Debt Instrument [Line Items]
Proceeds from exercise of warrants	$ 10,000
Series E
Debt Instrument [Line Items]
Debt instrument, conversion price (in dollars per share)				$ 1,198			$ 1,500
Avenue Loan
Debt Instrument [Line Items]
Debt instrument, principal face amount				$ 20,000
Interest rate				7.70%
Debt instrument, interest rate				10.95%			16.20%
Initial tranche of loan				$ 15,000
Loan amount funded into restricted account				4,000
Restricted cash			$ 4,000
Principal payments			$ 2,100
Debt instrument, incremental final payment, percentage			4.25%
Final payment			$ 200
Estimated minimum proceeds on issue of common stock for extension of due date of interest only interest payments		$ 10,000
Principal payments						$ 1,000
Principal amount hat may be converted to common stock				$ 3,000
Debt instrument, conversion price (in dollars per share)				$ 11.98
Amortization of debt discount							$ 300	$ 200
Interest expense incurred							300	500
Rosalind Notes
Debt Instrument [Line Items]
Debt instrument, principal face amount							$ 2,000
Interest rate							8%
Interest expense incurred							$ 100	$ 100

Preferred Purchase Agreement (D

Preferred Purchase Agreement (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Mar. 29, 2023	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Disclosure Of Preferred Purchase Agreement [Line Items]
Preferred stock, par value (in dollars per share)		$ 0.01	$ 0.01	$ 0.01
Fair value of warrant liabilities		$ 7,134	$ 6,544
Deferred revenue	$ 10,000	$ 10,000
Preferred stock, shares outstanding (in shares)		16,809	24,819
Preferred Warrant Liabilities
Disclosure Of Preferred Purchase Agreement [Line Items]
Proceeds from issuance of warrants	24,900
Fair value of warrant liabilities	$ 4,900
Preferred Purchase Agreement | Series F-1
Disclosure Of Preferred Purchase Agreement [Line Items]
Number of exercisable preferred warrants (in shares)	24,900
Preferred Purchase Agreement | Preferred Tranche A Warrant
Disclosure Of Preferred Purchase Agreement [Line Items]
Aggregate exercise price of preferred warrants		$ 34,900
Preferred Purchase Agreement | Preferred Tranche B Warrant
Disclosure Of Preferred Purchase Agreement [Line Items]
Number of exercisable preferred warrants (in shares)	24,900
Aggregate exercise price of preferred warrants		$ 24,900
Warrant exercise period		21 days
Preferred Purchase Agreement | Series F-4
Disclosure Of Preferred Purchase Agreement [Line Items]
Number of exercisable preferred warrants (in shares)		24,900
Series F1, Series F2 and F3 Preferred Stock
Disclosure Of Preferred Purchase Agreement [Line Items]
Conversion of shares (in shares)		54,207
Series F-1 | Preferred Warrant Liabilities
Disclosure Of Preferred Purchase Agreement [Line Items]
Proceeds from issuance of warrants	$ 20,000
Series F-1 | Preferred Purchase Agreement
Disclosure Of Preferred Purchase Agreement [Line Items]
Preferred stock, par value (in dollars per share)	$ 0.01
Series F-2
Disclosure Of Preferred Purchase Agreement [Line Items]
Preferred stock, par value (in dollars per share)		$ 3.30
Preferred stock, shares outstanding (in shares)		2,542
Series F-2 | Preferred Purchase Agreement
Disclosure Of Preferred Purchase Agreement [Line Items]
Preferred stock, par value (in dollars per share)		$ 0.01
Series F-3
Disclosure Of Preferred Purchase Agreement [Line Items]
Preferred stock, par value (in dollars per share)		$ 4.50
Preferred stock, shares outstanding (in shares)		3,010
Series F-3 | Preferred Tranche A Warrant
Disclosure Of Preferred Purchase Agreement [Line Items]
Number of exercisable preferred warrants (in shares)	34,859
Series F-3 | Preferred Purchase Agreement
Disclosure Of Preferred Purchase Agreement [Line Items]
Preferred stock, par value (in dollars per share)	$ 0.01
Common Stock
Disclosure Of Preferred Purchase Agreement [Line Items]
Number of shares converted (in shares)		13,853,143
Series F-4
Disclosure Of Preferred Purchase Agreement [Line Items]
Preferred stock, par value (in dollars per share)		$ 6
Preferred stock, shares outstanding (in shares)		0
Series F-4 | Preferred Purchase Agreement
Disclosure Of Preferred Purchase Agreement [Line Items]
Preferred stock, par value (in dollars per share)	$ 0.01

Stockholders' Equity - Equity O

Stockholders' Equity - Equity Offerings and Placements (Details) - USD ($) $ in Millions	Aug. 14, 2023	Mar. 29, 2023	Mar. 27, 2023	Mar. 31, 2024
Stockholders Equity Note [Line Items]
Deferred revenue		$ 10		$ 10
Tranche A Warrants | Common Purchase Agreement
Stockholders Equity Note [Line Items]
Number of exercisable common warrants (in shares)	31,110		31,110
Aggregate exercise price of preferred warrants		$ 0.1
Tranche B Warrants | Common Purchase Agreement
Stockholders Equity Note [Line Items]
Number of exercisable common warrants (in shares)		16,666	16,666
Aggregate exercise price of preferred warrants		$ 0.1
Warrants exercisable, period				21 days

Stockholders' Equity - At-the-M

Stockholders' Equity - At-the-Market Offering (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Stockholders Equity Note [Line Items]
Sale of stock consideration received on the transaction	$ 254	$ 228
Number of shares sold (in shares)	0
Controlled Equity Offering Sales Agreement | Cantor Fitzgerald & Co
Stockholders Equity Note [Line Items]
Common stock, aggregate offering price	$ 17,000
Sale of stock consideration received on the transaction	$ 4,000

Stockholders' Equity - Securiti

Stockholders' Equity - Securities Purchase Agreement (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended
	Mar. 19, 2024	Mar. 14, 2024	Aug. 06, 2021	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Stockholders Equity Note [Line Items]
Common stock, par value (in dollars per share)				$ 0.01	$ 0.01	$ 0.01
Warrants issued to purchase of common stock (in shares)			127,755
Warrant exercise price (in dollars per share)			$ 0.01		$ 0.01
Proceeds from private placement				$ 7,000	$ 22,960
PreFundedWarrants
Stockholders Equity Note [Line Items]
Warrants issued to purchase of common stock (in shares)		1,008,102
Private Placement
Stockholders Equity Note [Line Items]
Proceeds from private placement	$ 7,000
Private Placement | PreFundedWarrants
Stockholders Equity Note [Line Items]
Warrants issued to purchase of common stock, price per warrant (in dollars per share)		$ 3.71
Warrant exercise price (in dollars per share)		$ 0.01
Common Stock | Private Placement
Stockholders Equity Note [Line Items]
Stock issued during period, shares, new issues (in shares)		876,627
Common stock, par value (in dollars per share)		$ 0.01
Shares issued, price per share (in dollars per share)		$ 3.72

Stockholders' Equity - Designat

Stockholders' Equity - Designated Preferred Shares (Details)	Mar. 31, 2024 shares
Class of Stock [Line Items]
Preferred stock, shares designated (in shares)	179,670
Series A
Class of Stock [Line Items]
Preferred stock, shares designated (in shares)	4,200
Series B
Class of Stock [Line Items]
Preferred stock, shares designated (in shares)	2,360
Series C
Class of Stock [Line Items]
Preferred stock, shares designated (in shares)	590
Series D
Class of Stock [Line Items]
Preferred stock, shares designated (in shares)	10,000
Series E
Class of Stock [Line Items]
Preferred stock, shares designated (in shares)	40,000
Series E-1
Class of Stock [Line Items]
Preferred stock, shares designated (in shares)	12,960
Series F-1
Class of Stock [Line Items]
Preferred stock, shares designated (in shares)	24,900
Series F-2
Class of Stock [Line Items]
Preferred stock, shares designated (in shares)	24,900
Series F-3
Class of Stock [Line Items]
Preferred stock, shares designated (in shares)	34,860
Series F-4
Class of Stock [Line Items]
Preferred stock, shares designated (in shares)	24,900

Stockholders' Equity - Authoriz

Stockholders' Equity - Authorized Shares and Preferred Stock (Details) - $ / shares	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Stockholders Equity Note [Line Items]
Common stock, shares authorized (in shares)	80,000,000	80,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares outstanding (in shares)	16,809	24,819
Series E
Stockholders Equity Note [Line Items]
Preferred stock, shares outstanding (in shares)	11,257
Series E-1
Stockholders Equity Note [Line Items]
Preferred stock, shares outstanding (in shares)	11,257
Series F-2
Stockholders Equity Note [Line Items]
Preferred stock, par value (in dollars per share)	$ 3.30
Preferred stock, shares outstanding (in shares)	2,542
Series F-3
Stockholders Equity Note [Line Items]
Preferred stock, par value (in dollars per share)	$ 4.50
Preferred stock, shares outstanding (in shares)	3,010

Stockholders' Equity - Equity I

Stockholders' Equity - Equity Incentive Plan (Details)	Mar. 31, 2024 shares
2020 Plan
Class of Warrant or Right [Line Items]
Common stock, capital shares reserved (in shares)	5,125,000
Number of common shares remained available to be issued (in shares)	232,566
2023 Plan
Class of Warrant or Right [Line Items]
Common stock, capital shares reserved (in shares)	650,000
Number of shares available for grant (in shares)	372,000

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Assumptions to Estimate Fair Value of Stock Options Using Black-Scholes Option Pricing Model (Details)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Stockholders' Equity Note [Abstract]
Expected terms (years)	5 years 7 months 6 days	5 years 9 months 18 days
Expected volatility	115%	172.80%
Risk-free interest rate	4.19%	4.08%
Expected dividends	0%	0%

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Number of Options
Outstanding, beginning of period (in shares)	4,183,232
Granted (in shares)	2,017,596
Expired (in shares)	(15,341)
Cancelled/Forfeited (in shares)	(146,312)
Outstanding, end of period (in shares)	6,039,175	4,183,232
Exercisable (in shares)	2,569,497
Unvested at March 31, 2024 (in shares)	3,469,678
Weighted Average Exercise Price Per Share
Outstanding, Weighted Average Exercise Price Per Share, beginning of period (in dollars per share)	$ 8.17
Granted, Weighted Average Exercise Price Per Share (in dollars per share)	4.80
Expired, Weighted Average Exercise Price Per Share (in dollars per share)	7.16
Cancelled-Forfeited, Weighted Average Exercise Price Per Share (in dollars per share)	6.08
Outstanding, Weighted Average Exercise Price Per Share, end of period (in dollars per share)	7.10	$ 8.17
Weighted Average Exercise Price, Exercisable (in dollars per share)	9.47
Weighted Average Exercise Price, Unvested (in dollars per share)	5.34
Weighted Average Grant Date Fair Value Per Share
Outstanding, Weighted average grant date fair value at beginning of period (in dollars per share)	7.60
Weighted average estimated fair value of the stock options granted (in dollars per share)	3.92
Expired, Weighted average grant date fair value (in dollars per share)	6.91
Expired, Weighted average grant date fair value (in dollars per share)	5.75
Ending, Weighted average grant date fair value at beginning of period (in dollars per share)	6.42	$ 7.60
Exercisable, Weighted average grant date fair value (in dollars per share)	8.73
Unvested Weighted average grant date fair value (in dollars per share)	$ 4.70
Weighted Average Remaining Contractual Term (in years) and Aggregate Intrinsic Value
Weighted Average Remaining Contractual Term (in years), Outstanding	8 years 7 months 6 days	8 years 3 months 18 days
Weighted Average Remaining Contractual Term (in years), Granted	9 years 8 months 12 days
Weighted Average Remaining Contractual Term (in years), Exercisable	7 years 4 months 24 days
Weighted Average Remaining Contractual Term (in years), Unvested	9 years 4 months 24 days
Aggregate Intrinsic Value, Outstanding	$ 433	$ 147
Aggregate Intrinsic Value, Exercisable	74
Aggregate Intrinsic Value, Unvested	$ 358

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Stock Option Shares Outstanding and Exercisable (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding Number of Options (in shares)	6,039,175	4,183,232
Weighted Average Remaining Option Term (in years), Options Outstanding	8 years 7 months 6 days	8 years 3 months 18 days
Number of Options Exercisable (in shares)	6,039,175	4,183,232
$2.83 - $51.50
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding Number of Options (in shares)	6,038,676
Weighted Average Remaining Option Term (in years), Options Outstanding	8 years 7 months 6 days
Number of Options Exercisable (in shares)	6,038,676
$2.83 - $51.50 | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Range of Exercise Prices (in dollars per share)	$ 2.83
$2.83 - $51.50 | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Range of Exercise Prices (in dollars per share)	51.50
$51.50+
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Range of Exercise Prices (in dollars per share)	$ 51.50
Outstanding Number of Options (in shares)	499
Weighted Average Remaining Option Term (in years), Options Outstanding	4 years 9 months 18 days
Number of Options Exercisable (in shares)	499

Stockholders' Equity - Summar_3

Stockholders' Equity - Summary of Recognized Share-based Compensation Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	$ 2,945	$ 1,661
Unrecognized compensation expense related to non-vested share-based compensation awards	$ 10,300
Cost expected to be recognized over weighted average period	1 year 2 months 12 days
Selling, general and administrative
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	$ 2,042	1,118
Research and development
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	647	417
Cost of goods sold
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	$ 256	$ 126

Stockholders' Equity - Summar_4

Stockholders' Equity - Summary of Common Stock Warrant Activity (Details) - Common Warrants - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Class Of Warrant Or Right Outstanding [Roll Forward]
Outstanding, beginning of period (in shares)	4,665,201
Warrants issued (in shares)	1,008,102
Warrants exercised (in shares)	0
Outstanding, end of period (in shares)	5,673,303	4,665,201
Exercisable, end of period (in shares)	5,673,303
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)	$ 7.76
Warrants issued (in dollars per share)	0.01
Warrants exercised (in dollars per share)	0
Outstanding, ending of period (in dollars per share)		$ 7.76
Exercisable, (in dollars per share)	$ 6.39
Weighted Average Remaining Life (in years)
Weighted Average Remaining Life (in years), Outstanding	2 years	1 year 7 months 6 days
Weighted Average Remaining Life, Issued	5 years
Weighted Average Remaining Life, Exercisable	2 years

Stockholders' Equity - Summar_5

Stockholders' Equity - Summary of Common Stock Warrants Outstanding and Exercisable (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Aug. 06, 2021
Class of Warrant or Right [Line Items]
Warrant exercise price (in dollars per share)			$ 0.01	$ 0.01
Common Warrants
Class of Warrant or Right [Line Items]
Outstanding Number of Warrants (in shares)	5,673,303	4,665,201
Warrants Exercisable, Weighted Average Remaining Warrant Term (in years)	2 years	1 year 7 months 6 days
Warrants Exercisable, Number of Warrants (in shares)	5,673,303
$0.01
Class of Warrant or Right [Line Items]
Warrant exercise price (in dollars per share)	$ 0.01
$0.01 | Common Warrants
Class of Warrant or Right [Line Items]
Outstanding Number of Warrants (in shares)	2,045,894
Warrants Exercisable, Weighted Average Remaining Warrant Term (in years)	4 years
Warrants Exercisable, Number of Warrants (in shares)	2,045,894
$6.00
Class of Warrant or Right [Line Items]
Warrant exercise price (in dollars per share)	$ 6
$6.00 | Common Warrants
Class of Warrant or Right [Line Items]
Outstanding Number of Warrants (in shares)	16,666
Warrants Exercisable, Weighted Average Remaining Warrant Term (in years)	2 years
Warrants Exercisable, Number of Warrants (in shares)	16,666
$10.00
Class of Warrant or Right [Line Items]
Warrant exercise price (in dollars per share)	$ 10
$10.00 | Common Warrants
Class of Warrant or Right [Line Items]
Outstanding Number of Warrants (in shares)	3,610,743
Warrants Exercisable, Weighted Average Remaining Warrant Term (in years)	1 year
Warrants Exercisable, Number of Warrants (in shares)	3,610,743

Stockholders' Equity - Preferre

Stockholders' Equity - Preferred Stock Warrants (Details) - Preferred Warrants - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Class of Warrant or Right [Line Items]
Outstanding, beginning of period (in shares)	24,900
Warrants issued (in shares)	0
Warrants exercised (in shares)	0
Outstanding, end of period (in shares)	24,900	24,900
Warrants Exercisable, Number of Warrants (in shares)	24,900
Outstanding, beginning of period (in dollars per share)	$ 1,000
Warrants issued (in dollars per share)
Warrants exercised (in dollars per share)
Outstanding, ending of period (in dollars per share)	1,000	$ 1,000
Warrants Exercisable, Weighted Average Exercise Price	$ 1,000
Warrants Exercisable, Weighted Average Remaining Warrant Term (in years)	2 years	2 years 3 months 18 days
Weighted Average Remaining Life, Exercisable	2 years

Stockholders' Equity - Summar_6

Stockholders' Equity - Summary of Employee Stock Purchase Plan (Details) - shares	1 Months Ended	3 Months Ended
	Aug. 31, 2021	Mar. 31, 2024
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Employee stock purchase plan, offering period		6 months
May 2022 Employee Stock Purchase Plan
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Share-based compensation arrangement by share-based payment award number of shares authorized (in shares)	260,295	62,575
Share-based compensation arrangement by share-based payment award purchase price of common stock (as a percent)	85%

Net Loss per Share - Anti-Dilut

Net Loss per Share - Anti-Dilutive Securities Excluded from Computation of Earnings Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	16,869,520	27,618,787
Common stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	3,627,409	3,658,520
Assumed conversion of preferred stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	4,149,994	11,896,667
Assumed conversion of preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	2,564,911	8,681,176
Assumed conversion of convertible notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	488,031	488,031
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	6,039,175	2,894,393

Net Loss per Share - Narrative

Net Loss per Share - Narrative (Details) - shares	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share [Abstract]
Pre-funded penny warrants outstanding	2,045,894	1,576,620

Net Loss per Share - Summary of

Net Loss per Share - Summary of Reconciliation of Weighted Average Shares Outstanding Calculation (Details) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share [Abstract]
Weighted average shares issued (in shares)	23,705,374	10,081,634
Weighted average pre-funded warrants (in shares)	1,181,806	1,540,750
Weighted average number of basic shares outstanding (in shares)	24,887,180	11,622,384
Weighted average number of diluted shares outstanding (in shares)	24,887,180	11,622,384

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands, € in Millions	May 01, 2024	Dec. 30, 2022 USD ($)	Mar. 31, 2024 USD ($)	Oct. 12, 2021 EUR (€)	Apr. 30, 2021 EUR (€)
Loss Contingencies [Line Items]
Milestone payment unpaid | €				€ 1
Purchase obligation, remainder of fiscal year			$ 2,250
Subsequent Event
Loss Contingencies [Line Items]
Supply agreement, renewal option term	5 years
Medac
Loss Contingencies [Line Items]
Accounts receivable | €					€ 1
Term over which the royalty is to be paid		5 years
Minimum annual payments		$ 200
Other Liabilities | Medac
Loss Contingencies [Line Items]
Loss contingency accrual			1,000
Other Noncurrent Liabilities | Medac
Loss Contingencies [Line Items]
Loss contingency accrual			800
Accrued Expenses | Medac
Loss Contingencies [Line Items]
Loss contingency accrual			$ 200

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Measurements Using Significant Unobservable Inputs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 6,544
Total change in foreign exchange	(22)
Warrant liability fair value adjustment	612	$ 0
Change due to warrant exercise	0
Ending balance	7,134
Contingent liabilities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	996
Total change in foreign exchange	(22)
Warrant liability fair value adjustment	0
Change due to warrant exercise	0
Ending balance	974
Warrants
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	5,548
Total change in foreign exchange	0
Warrant liability fair value adjustment	612
Change due to warrant exercise	0
Ending balance	$ 6,160

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Other expense related to the change in fair value of the warrant liability	$ 612	$ 0

Fair Value Measurements - Fai_2

Fair Value Measurements - Fair Value Assumptions for Warrants (Details) - Valuation Technique, Option Pricing Model - Preferred And Common Warrants	Mar. 31, 2024	Dec. 31, 2023
Risk free interest rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	0.0449	0.0409
Expected term (years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	2	2.3
Expected volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	0.65	0.70
Expected dividends
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	0	0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of the Company's Financial Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets:
Total Assets	$ 15,432	$ 20,200
Liabilities:
Contingent Liability	974	996
Warrant Liabilities	6,160	5,548
Total Liabilities	7,134	6,544
Money market funds
Assets:
Investments	72	392
U.S. government agency bonds
Assets:
Investments	15,360	19,808
Quoted Prices in Active Markets (Level 1)
Assets:
Total Assets	72	392
Liabilities:
Contingent Liability	0	0
Warrant Liabilities	0	0
Total Liabilities	0	0
Quoted Prices in Active Markets (Level 1) | Money market funds
Assets:
Investments	72	392
Quoted Prices in Active Markets (Level 1) | U.S. government agency bonds
Assets:
Investments	0	0
Significant Other Observable Inputs (Level 2)
Assets:
Total Assets	15,360	19,808
Liabilities:
Contingent Liability	0	0
Warrant Liabilities	0	0
Total Liabilities	0	0
Significant Other Observable Inputs (Level 2) | Money market funds
Assets:
Investments	0	0
Significant Other Observable Inputs (Level 2) | U.S. government agency bonds
Assets:
Investments	15,360	19,808
Significant Unobservable Inputs (Level 3)
Assets:
Total Assets	0	0
Liabilities:
Contingent Liability	974	996
Warrant Liabilities	6,160	5,548
Total Liabilities	7,134	6,544
Significant Unobservable Inputs (Level 3) | Money market funds
Assets:
Investments	0	0
Significant Unobservable Inputs (Level 3) | U.S. government agency bonds
Assets:
Investments	$ 0	$ 0