Delcath Systems (DCTH) S-1 15 Aug 18 IPO registration Financial data

Document and Entity Information

Document and Entity Information	6 Months Ended
	Jun. 30, 2018
Document And Entity Information [Abstract]
Document Type	S1
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Trading Symbol	DCTH
Entity Registrant Name	DELCATH SYSTEMS, INC.
Entity Central Index Key	872,912
Entity Filer Category	Accelerated Filer

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands		Jun. 30, 2018		Dec. 31, 2017		Dec. 31, 2016
Current assets
Cash and cash equivalents		$ 1,283		$ 3,999		$ 4,409
Restricted cash		1,062		1,325		27,287
Accounts receivables, net		397		317		403
Inventories		1,250		1,248		660
Prepaid expenses and other current assets		382		700		698
Deferred financing costs				0		699
Total current assets		4,374		7,589		34,156
Property, plant and equipment, net		1,099		1,298		1,083
Total assets		5,473		8,887		35,239
Current liabilities
Accounts payable		5,607		3,846		594
Accrued expenses		5,220		3,408		3,407
Current portion of convertible notes payable, net of discount		387		0		13,343
Warrant liability		6,883		560		18,751
Total current liabilities		18,097		7,814		36,095
Convertible notes payable, net of current portion and debt discount		27		0
Deferred revenue				0		30
Other non-current liabilities		439		395		604
Total liabilities		18,563		8,209		36,729
Commitments and Contingencies
Stockholders' equity (deficit)
Preferred stock		0		0		0
Common stock		9	[1]	3	[1]	0	[2]
Additional paid-in capital		311,293		325,516		277,790
Accumulated deficit		(324,305)		(324,832)		(279,188)
Treasury stock		(51)	[1]	(51)	[1],[2]	(51)	[2]
Accumulated other comprehensive income		(36)		42		(41)
Total stockholders' (deficit) equity		(13,090)		678		(1,490)
Total liabilities and stockholders' equity		$ 5,473		8,887		$ 35,239
Previously Reported [Member]
Stockholders' equity (deficit)
Common stock	[2]			2
Additional paid-in capital				$ 325,517
[1]	reflects a one-for-three hundred and fifty (1:350) reverse stock split effected on November 6, 2017 and a one-for-five hundred (1:500) reverse stock split effected on May 2, 2018.
[2]	reflects a one-for-sixteen (1:16) reverse stock split effected on July 21, 2016, a one-for-three hundred and fifty (1:350) reverse stock split effected on November 6, 2017 and a one-for-five hundred (1:500) reverse stock split effected on May 2, 2018.

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Preferred 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	10,000,000
Preferred stock, shares issued (in shares)	0	0	0
Preferred stock, shares outstanding (in shares)	0	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000	500,000,000
Common stock, shares issued (in shares)	932,159	263,305	24
Common stock, shares outstanding (in shares)	932,158	263,304	23
Treasury stock, at cost (in shares)	1	1	1
Previously Reported [Member]
Common stock, shares authorized (in shares)		500,000,000
Common stock, shares issued (in shares)		228,140
Common stock, shares outstanding (in shares)		228,139

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Revenue		$ 858	$ 584	$ 1,560	$ 1,327	$ 2,715	$ 1,992	$ 1,747
Cost of goods sold		220	135	367	354	701	550	462
Gross profit		638	449	1,193	973	2,014	1,442	1,285
Operating expenses:
Selling, general and administrative expenses		2,641	2,532	5,007	4,947	9,684	9,434	10,009
Research and development expenses		4,089	2,518	9,781	4,840	10,495	8,448	6,486
Total operating expenses		6,730	5,050	14,788	9,787	20,179	17,882	16,495
Operating loss		(6,092)	(4,601)	(13,595)	(8,814)	(18,165)	(16,440)	(15,210)
Change in fair value of the warrant liability, net		2,513	(38)	17,209	1,200	15,103	12,780	564
Gain on warrant extinguishment		0	9,613	0	9,613	9,613	0	0
Loss on issuance of financial instrument		(2,826)	0	(2,826)	0
Loss on debt settlements and extinguishments						(29,924)	0	0
Interest expense		(248)	(6,916)	(251)	(15,282)	(21,703)	(14,328)	(67)
Other (expense) income		(5)	(1)	(10)	7	(41)	17	9
Net income (loss)		(6,658)	(1,943)	527	(13,276)	(45,117)	(17,971)	(14,704)
Other comprehensive loss:
Foreign currency translation adjustments		(36)	(30)	(78)	(8)	83	(33)	(28)
Comprehensive loss		$ (6,694)	$ (1,973)	$ 449	$ (13,284)	$ (45,034)	$ (18,004)	$ (14,732)
Common share data:
Basic and diluted loss per common share	[1]					$ (3,250)	$ (1,853,500)	$ (2,548,000)
Basic loss per common share	[2]	$ (7.26)	$ (1,373)	$ 0.67	$ (15,656)
Diluted loss per common share	[2]	$ (7.26)	$ (1,373)	$ (0.12)	$ (15,656)
Weighted average number of basic shares outstanding	[2]	916,706	1,416	788,512	848
Weighted average number of diluted shares outstanding	[2]	916,706	1,416	799,430	848
Weighted average number of basic and diluted shares outstanding	[1]					14,039	10	6
[1]	reflects a one-for-sixteen (1:16) reverse stock split effected on July 21, 2016, a one-for-three hundred and fifty (1:350) reverse stock split effected on November 6, 2017 and a one-for-five hundred (1:500) reverse stock split effected on May 2, 2018.
[2]	reflects a one-for-three hundred and fifty (1:350) reverse stock split effected on November 6, 2017 and a one-for-five hundred (1:500) reverse stock split effected on May 2, 2018.

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Operations and Comprehensive Loss (Parenthetical)	May 02, 2018	Nov. 06, 2017	Jul. 21, 2016
Income Statement [Abstract]
Reverse stock split	1:500	1:350
Reverse stock split ratio	0.0020	0.0029	0.0625

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Stockholders' Deficit - USD ($) $ in Thousands	Total	Common Stock Issued [Member]	Common Stock Issued [Member]Previously Reported [Member]	Treasury Stock [Member]	Additional Paid in Capital [Member]	Additional Paid in Capital [Member]Previously Reported [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2014	$ 18,145			$ (51)	$ 264,689		$ (246,513)	$ 20
Balance (in shares) at Dec. 31, 2014		5		(1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation expense/income for issuance of stock options	349				349
Compensation expense (income) for issuance of restricted stock	308				308
Sale of common stock, net of expenses	8,479				8,479
Sale of common stock, net of expenses (in shares)		4
Exercise of warrants	176				176
Fair value of warrants issued classified as liability	(4,247)				(4,247)
Fair value of warrants exercised	123				123
Net income (loss)	(14,704)						(14,704)
Foreign currency translation	(28)							(28)
Balance at Dec. 31, 2015	8,601			$ (51)	269,877		(261,217)	(8)
Balance (in shares) at Dec. 31, 2015		9		(1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation expense/income for issuance of stock options	161				161
Compensation expense (income) for issuance of restricted stock	266				266
Sale of common stock, net of expenses	1,011				1,011
Sale of common stock, net of expenses (in shares)		2
Issuance of common stock and rights for payments made in shares on convertible notes payable	649				649
Issuance of common stock and rights for payments made in shares on convertible notes payable (in shares)		10
Fair value of beneficial conversion feature of convertible note	4,435				4,435
Exercise of warrants	1,372				1,372
Exercise of warrants (in shares)		3
Fair value of warrants issued classified as liability	(707)				(707)
Fair value of warrants exercised	726				726
Net income (loss)	(17,971)						(17,971)
Foreign currency translation	(33)							(33)
Balance at Dec. 31, 2016	(1,490)			$ (51)	277,790		(279,188)	(41)
Balance (in shares) at Dec. 31, 2016		24		(1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation expense/income for issuance of stock options	50				50
Compensation expense (income) for issuance of restricted stock	79	$ 0			79
Issuance of common stock and rights for payments made in shares on convertible notes payable	40,121	$ 2			40,119
Issuance of common stock and rights for payments made in shares on convertible notes payable (in shares)		227,287
Fair value of beneficial conversion feature of convertible note	4,908				4,908
Series B preferred stock dividend	(527)						(527)
Exercise of warrants	19				19
Exercise of warrants (in shares)		736
Fair value of warrants exercised	2,552				2,552
Adjustment for rounding related to Nov 2017 reverse stock split, (in shares)		93
Net income (loss)	(45,117)						(45,117)
Foreign currency translation	83							83
Balance at Dec. 31, 2017	678	$ 3	$ 2	$ (51)	325,516	$ 325,517	(324,832)	42
Balance (in shares) at Dec. 31, 2017		263,305	228,140	(1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation expense/income for issuance of stock options	(40)				(40)
Compensation expense (income) for issuance of restricted stock	(81)				(81)
Sale of common stock, net of expenses	$ 4,210	$ 6			4,204
Sale of common stock, net of expenses (in shares)	424,000	668,854
Fair value of warrants issued	$ (18,306)				(18,306)
Net income (loss)	527						527
Foreign currency translation	(78)
Total comprehensive loss	(78)							(78)
Balance at Jun. 30, 2018	$ (13,090)	$ 9		$ (51)	$ 311,293		$ (324,305)	$ (36)
Balance (in shares) at Jun. 30, 2018		932,159		(1)

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Stockholders' Deficit (Parenthetical)	May 02, 2018	Nov. 06, 2017	Jul. 21, 2016$ / shares	Jun. 30, 2018$ / shares	Dec. 31, 2017$ / shares	Dec. 31, 2016$ / shares
Statement of Stockholders' Equity [Abstract]
Reverse stock split ratio	0.0020	0.0029	0.0625
Common stock issued, par value			$ 0.01	$ 0.01	$ 0.01	$ 0.01

Condensed Consolidated Stateme8

Condensed Consolidated Statements of Cash Flows - USD ($)	3 Months Ended		6 Months Ended			12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2017	Dec. 28, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income (loss)			$ 527,000		$ (13,276,000)	$ (45,117,000)		$ (17,971,000)	$ (14,704,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock option compensation (income) expense			(40,000)		46,000	50,000		161,000	349,000
Restricted stock compensation (income) expense			(81,000)		64,000	79,000		266,000	308,000
Depreciation expense	$ 100,000	$ 100,000	236,000		127,000	310,000		305,000	617,000
Loss on disposal of equipment			0		20,000	18,000		1,000	15,000
Warrant liability fair value adjustment	(2,513,000)	38,000	(17,209,000)		(1,200,000)	(15,103,000)		(12,780,000)	(564,000)
Gain on warrant extinguishment	0	(9,613,000)	0		(9,613,000)	(9,613,000)		0	0
Non-cash interest income			(1,000)		(1,000)	(1,000)		(1,000)	(1,000)
Debt discount and deferred finance costs amortization						21,544,000		14,268,000	0
Deferred revenue			0		2,000	(32,000)		30,000	0
Loss on debt settlements and extinguishments						29,924,000		0	0
Loss on issuance of financial instrument	2,826,000	0	2,826,000		0
Debt discount amortization			238,000		15,277,000
Changes in assets and liabilities:
Prepaid expenses and other assets			318,000		201,000	7,000		260,000	9,000
Accounts receivable			(163,000)		(94,000)	108,000		(138,000)	(52,000)
Inventories			43,000		(208,000)	(543,000)		95,000	(420,000)
Accounts payable and accrued expenses			3,985,000		628,000	3,180,000		1,507,000	(1,757,000)
Deferred revenue			0		2,000	(32,000)		30,000	0
Other non-current liabilities			44,000		(110,000)	(209,000)		(216,000)	(220,000)
Net cash used in operating activities			(9,277,000)		(8,137,000)	(15,398,000)		(14,213,000)	(16,420,000)
Cash flows from investing activities:
Purchase of property, plant and equipment			(39,000)		(276,000)	(524,000)		(258,000)	(170,000)
Increase in restricted cash						0		(1,087,000)	0
Proceeds from sales of property, plant and equipment						0		0	180,000
Net cash (used in) provided by investing activities			(39,000)		(276,000)	(524,000)		(1,345,000)	10,000
Cash flows from financing activities:
Increase in restricted cash						0		(26,200,000)	0
Net proceeds from the release of restricted cash			263,000		5,954,000	13,120,000		0	0
Net proceeds from sale of Series B and Series C preferred shares						2,310,000		0	0
Net proceeds from convertible note debt financing			2,172,000		0	0		31,226,000	0
Net proceeds from sale of stock			4,210,000		15,000	15,000		2,383,000	8,655,000
Net cash provided by financing activities			6,645,000		5,969,000	15,445,000		7,409,000	8,655,000
Foreign currency effects on cash and cash equivalents			(45,000)		(149,000)	67,000		(49,000)	(107,000)
Increase (decrease) in cash and cash equivalents			(2,716,000)		(2,593,000)	(410,000)		(8,198,000)	(7,862,000)
Cash and cash equivalents:
Beginning of period			3,999,000	$ 1,816,000	4,409,000	4,409,000	$ 4,409,000	12,607,000	20,469,000
End of period	$ 1,283,000	$ 1,816,000	1,283,000	$ 3,999,000	1,816,000	3,999,000		4,409,000	12,607,000
Supplemental non-cash financing activities:
Conversion of convertible notes			0		15,831,000	40,121,000	$ 35,000,000	649,000	0
Fair value of warrants issued			23,532,000		0	16,953,000		28,472,000	4,247,000
Cashless exercise of warrants						2,537,000		0	0
Fair value of warrants exercised			0		19,000,000	2,552,000		726,000	123,000
Deemed dividend						527,000		0	0
Fair value of warrants exercised for cash						19,000		726,000	123,000
Series A and Series B Preferred Shares [Member]
Cash flows from financing activities:
Release of restricted cash for redemption of preferred shares						2,360,000		0	0
Cash paid to redeem preferred shares						(2,360,000)		0	0
Series C Preferred Shares [Member]
Cash flows from financing activities:
Release of restricted cash for redemption of preferred shares						590,000		0	0
Cash paid to redeem preferred shares						(590,000)		0	0
Series C Warrants [Member]
Cash flows from financing activities:
Release of restricted cash for extinguishment of Series C Warrants			0		7,876,000	7,876,000		0	0
Cash paid to extinguish of Series C Warrants			$ 0		$ (7,876,000)	$ (7,876,000)		$ 0	$ 0

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	(1) Description of Business Delcath Systems, Inc. is an interventional oncology company focused on the treatment of primary and metastatic liver cancers. Our investigational product—Melphalan Hydrochloride for Injection for use with the Delcath Hepatic Delivery System (Melphalan/HDS) —is designed to administer high-dose chemotherapy to the liver while controlling systemic exposure and associated side effects. In Europe, our system is commercially available under the trade name Delcath Hepatic CHEMOSAT ® ® Our primary research focus is on ocular melanoma liver metastases (mOM) and intrahepatic cholangiocarcinoma (ICC), a type of primary liver cancer, and certain other cancers that are metastatic to the liver. We believe the disease states we are investigating represent a multi-billion dollar global market opportunity and a clear unmet medical need. Liquidity The accompanying financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The Company has incurred losses since inception and has accumulated deficit of $324.8 million at December 31, 2017. As shown in the accompanying financial statements during the year ended December 31, 2017, the Company incurred net losses of $45.1 million and used $15.4 million of cash for its operating activities. These factors among others raise substantial doubt about the Company’s ability to continue as a going concern for a reasonable period of time. The Company’s existence is dependent upon management’s ability to obtain additional funding sources or to enter into strategic alliances. Adequate additional financing may not be available to us on acceptable terms, or at all. If the Company is unable to raise additional capital and/or enter into strategic alliances when needed or on attractive terms, it would be forced to delay, reduce or eliminate our research and development programs or any commercialization efforts. There can be no assurance that the Company’s efforts will result in the resolution of the Company’s liquidity needs. If Delcath is not able to continue as a going concern, it is likely that holders of its common stock will lose all of their investment. The accompanying consolidated financial statements do not include any adjustments that might result should the Company be unable to continue as a going concern. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales. Management believes that its capital resources are adequate to fund operations through May 2018. Additional working capital will be required to continue operations. Operations of the Company are subject to certain risks and uncertainties, including, among others, uncertainty of product development and clinical trial results; uncertainty regarding regulatory approval; technological uncertainty; uncertainty regarding patents and proprietary rights; comprehensive government regulations; limited commercial manufacturing, marketing or sales experience; and dependence on key personnel.

Basis of Consolidated Financial

Basis of Consolidated Financial Statement Presentation	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Consolidated Financial Statement Presentation	(2) Basis of Consolidated Financial Statement Presentation The accounting and financial reporting policies of the Company conform to generally accepted accounting principles in the United States of America (GAAP). The preparation of consolidated financial statements in conformity with GAAP requires management to make assumptions and estimates that impact the amounts reported in the Company’s consolidated financial statements. The consolidated financial statements include the accounts of all entities controlled by Delcath. All significant inter-company accounts and transactions are eliminated.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	(3) Summary of Significant Accounting Policies Use of Estimates The Company bases its estimates and judgments on historical experience and on various other assumptions that it believes are reasonable under the circumstances. The amounts of assets and liabilities reported in the Company’s consolidated balance sheets and the amount of revenues and expenses reported for each of the periods presented are affected by estimates and assumptions, which are used for, but not limited to, the accounting for derivative instrument liabilities, stock-based compensation, valuation of inventory, impairment of long-lived assets, income taxes and operating expense accruals. Such assumptions and estimates are subject to change in the future as additional information becomes available or as circumstances are modified. Actual results could differ from these estimates. Cash Equivalents and Concentrations of Credit Risk The Company considers investments with original maturities of three months or less at date of acquisition to be cash equivalents. The Company has deposits that exceed amounts insured by the Federal Deposit Insurance Corporation (FDIC), however, the Company does not consider this a significant concentration of credit risk based on the strength of the financial institution. Restricted Cash Cash and cash equivalents that are restricted as to withdrawal or use under the terms of certain contractual agreements are recorded as restricted cash on the accompanying consolidated balance sheets. Accounts Receivable Accounts receivable, principally trade, are generally due within 30 days and are stated at amounts due from customers. Collections and payments from customers are monitored and a provision for estimated credit losses may be created based upon historical experience and specific customer collection issues that may be identified. Inventories Inventories are valued at the lower of cost or market value using the first-in, first-out method. The products, work-in-process, and Prior to obtaining authorization to affix the CE Mark to its Generation Two CHEMOSAT System in April 2012, the Company expensed all of its inventory costs as research and development. Inventory as of December 31, 2017 includes finished goods and components that have been purchased since April 2012. Therefore, to the extent that materials expensed prior to April 2012 are used in manufacturing finished goods for sale, the Company’s cost of goods sold will be impacted accordingly. Property, Plant and Equipment Property, plant and equipment are recorded at cost, less accumulated depreciation. The Company provides for depreciation on a straight line basis over the estimated useful lives of the assets which range from three to seven years. Leasehold improvements will be amortized over the shorter of the lease term or the estimated useful life of the related assets when they are placed into service. The Company evaluates property, plant and equipment for impairment periodically to determine if changes in circumstances or the occurrence of events suggest the carrying value of the asset or asset group may not be recoverable. Maintenance and repairs are charged to operations as incurred. Expenditures which substantially increase the useful lives of the related assets are capitalized. Derivative Instrument Liability The Company accounts for derivative instruments in accordance with Accounting Standards Codification (ASC) 815, which establishes accounting and reporting standards for derivative instruments and hedging activities, including certain derivative instruments embedded in other financial instruments or contracts and requires recognition of all derivatives on the balance sheet at fair value, regardless of the hedging relationship designation. Accounting for changes in the fair value of the derivative instruments depends on whether the derivatives qualify as hedge relationships and the types of relationships designated are based on the exposures hedged. At December 31, 2017 and 2016, the Company did not have any derivative instruments that were designated as hedges. Fair Value Measurements The Company adheres to ASC 820, which defines fair value, establishes a framework for measuring fair value, and expands disclosures about fair value measurements. ASC 820 applies to reported balances that are required or permitted to be measured at fair value under existing accounting pronouncements; accordingly, the standard does not require any new fair value measurements of reported balances. ASC 820 emphasizes that fair value is a market-based measurement, not an entity-specific measurement. Therefore, a fair value measurement should be determined based on the assumptions that market participants would use in pricing the asset or liability. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a fair value hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity (observable inputs that are classified within Levels 1 and 2 of the hierarchy) and the reporting entity’s own assumptions about market participant assumptions (unobservable inputs classified within Level 3 of the hierarchy). • Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access. • Level 2 inputs are inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs may include quoted prices for similar assets and liabilities in active markets, as well as inputs that are observable for the asset or liability (other than quoted prices), such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals. • Level 3 inputs are unobservable inputs for the asset or liability, which is typically based on an entity’s own assumptions, as there is little, if any, related market activity. In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability. Revenue Recognition Revenue from product sales is generally recognized when all of the following criteria have been met: persuasive evidence of an arrangement exists; delivery has occurred; product price is fixed or determinable; and collection of the resulting receivable is reasonably assured. When obligations or contingencies remain after the products are shipped, such as training and certifying the treatment centers, revenue is deferred until the obligations or contingencies are satisfied. Deferred Revenue Deferred revenue on the accompanying consolidated balance sheets includes payment received for product sales to a distributor. When obligations or contingencies remain after the products are shipped, such as training and certifying the treatment centers, revenue is deferred until the obligations or contingencies are satisfied. The Company will recognize the revenue related to product sales when its obligations under the agreement have been satisfied. Selling, General and Administrative Selling, general and administrative costs include personnel costs and related expenses for the Company’s sales, marketing, general management and administrative staff, recruitment, costs related to the Company’s commercialization efforts in Europe, professional service fees, professional license fees, business development and certain general legal activities. All such costs are charged to expense when incurred. Research and Development Research and development costs include the costs of materials used for clinical trials and R&D, personnel costs associated with device and pharmaceutical R&D, clinical affairs, medical affairs, medical science liaisons, and regulatory affairs, costs of outside services and applicable indirect costs incurred in the development of the Company’s proprietary drug delivery system. All such costs are charged to expense when incurred. Stock Based Compensation The Company accounts for its share-based compensation in accordance with the provisions of ASC 718, which establishes accounting for equity instruments exchanged for employee services and ASC 505-50, which to non-employees. Under ASC 505-50, measurement to non-employees for of non-employee stock-based The Company periodically grants stock options for a fixed number of shares of common stock to its employees, directors and non-employee Income Taxes The Company accounts for income taxes following the asset and liability method in accordance with the ASC 740 “Income Taxes.” Under such method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax bases. The Company applies the accounting guidance issued to address the accounting for uncertain tax positions. This guidance clarifies the accounting for income taxes, by prescribing a minimum recognition threshold a tax position is required to meet before being recognized in the financial statements as well as provides guidance on derecognition, measurement, classification, interest and penalties, accounting in interim periods, disclosure and transition. The Company classifies interest and penalty expense related to uncertain tax positions as a component of income tax expense. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years that the asset is expected to be recovered or the liability settled. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The ultimate realization of deferred tax assets depends on the generation of future taxable income during the period in which related temporary differences become deductible. The Company considers the scheduled reversal of deferred tax liabilities, projected future taxable income and tax planning strategies in its assessment of a valuation allowance. See Note 13 for additional information. Net Loss per Common Share Basic net loss per share is determined by dividing net loss by the weighted average shares of common stock outstanding during the period. 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 stock options, unvested restricted stock and warrants are deemed anti-dilutive such that basic net loss per share and diluted net loss per share are equal. The calculation of net loss and the number of shares used to compute basic and diluted earnings per share for the years ended December 31, 2017, 2016 and 2015 are as follows: (in thousands, except share data) 2017 2016 2015 Net loss $ (45,117 ) $ (17,971 ) $ (14,704 ) Preferred stock dividends (527 ) — — Net loss, adjusted (45,644 ) (17,971 ) (14,704 ) Net loss per share – basic and diluted (3,250 ) (1,853,500 ) (2,548,000 ) Weighted average shares outstanding – basic and diluted 14,039 10 6 In the third quarter of 2017, the Company issued Series B Preferred Shares. A portion of the redemption price of the Series B Preferred Shares was accounted for as a deemed dividend and is discussed further in Note 10. For the years ended December 31, 2017, 2016 and 2015, the following potentially dilutive securities were excluded from the computation of diluted earnings per share (EPS) because their effects would be antidilutive. Shares excluded from the computation of diluted EPS: 2017 2016 2015 Stock options — — — Unvested restricted shares — — — Warrants 14,049 41 65 Total 14,049 41 63 Segment Information The Company currently operates in one business segment, which is the development and commercialization of CHEMOSAT/Melphalan/HDS. A single management team that reports to the CEO and President comprehensively manages the business. Accordingly, the Company does not have separately reportable segments. Foreign Currency and Currency Translation Transactions that are denominated in a foreign currency are remeasured into the functional currency at the current exchange rate on the date of the transaction. Any foreign currency-denominated monetary assets and liabilities are subsequently remeasured at current exchange rates, with gains or losses recognized as foreign exchange (losses)/gains in the statements of operations. The assets and liabilities of the Company’s international subsidiaries are translated from their functional currencies into United States dollars at exchange rates prevailing at the balance sheet date. Average rates of exchange during the period are used to translate the statement of operations, while historical rates of exchange are used to translate any equity transactions. Translation adjustments arising on consolidation due to differences between average rates and balance sheet rates, as well as unrealized foreign exchange gains or losses arising from translation of intercompany loans that are of a long-term-investment nature, are recorded in other comprehensive income. Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, Revenue (“ASU 2014-09”) that ASU 2014-09 also ASU 2014-09 is ASU 2014-09 compared ASU 2014-09 to In February 2016, the FASB issued ASU No. 2016-02, Leases, a right-to-use asset ASU 2016-02 is In June 2016, the FASB issued ASU 2016-15, Statement In November 2016, the FASB issued ASU 2016-18, Statement ASU 2016-18 is In July 2017, the FASB issued ASU 2017-11, Earnings Board re-characterized the The re-characterization has ASU 2017-11 is

Inventories

Inventories	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Inventories	(2) Inventories Inventories consist of the following: (in thousands) June 30, 2018 December 31, 2017 Raw materials $ 339 $ 298 Work-in-process 755 721 Finished goods 156 229 Total inventories $ 1,250 $ 1,248	(4) Inventories Inventories consist of: (in thousands) December 31, December 31, Raw materials $ 298 $ 346 Work-in-process 721 214 Finished goods 229 100 Total Inventory $ 1,248 $ 660

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	(3) Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following: (in thousands) June 30, 2018 December 31, 2017 Insurance premiums $ 168 $ 421 Security deposit 50 50 VAT/GST receivable 37 29 Software 26 15 Financing costs 25 70 Other 1 76 115 Total prepaid expenses and other current assets $ 382 $ 700 1 Other consists of various prepaid expenses and other current assets, with no individual item accounting for more than 5% of prepaid expenses and other current assets at June 30, 2018 and December 31, 2017.	(5) Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets include the following: (in thousands) December 31, December 31, Insurance premiums $ 421 $ 501 Financing costs 70 — Security deposit 50 50 Other 1 159 147 Total prepaid expenses and other current assets $ 700 $ 698 1 Other consists of various prepaid expenses and other current assets, with no individual item accounting for more than 5% at December 31, 2017 and 2016.

Property, Plant, and Equipment

Property, Plant, and Equipment	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment	(4) Property, Plant, and Equipment Property, plant, and equipment consist of the following: (in thousands) June 30, 2018 December 31, 2017 Buildings and land $ 579 $ 579 Enterprise hardware and software 1,743 1,744 Leaseholds 1,702 1,705 Equipment 979 971 Furniture 199 175 Property, plant and equipment, gross 5,202 5,174 Accumulated depreciation (4,103 ) (3,876 ) Property, plant and equipment, net $ 1,099 $ 1,298 Depreciation expense for the three and six months ended June 30, 2018 was approximately $0.1 million and $0.2 million, respectively, as compared to approximately $0.1 million and $0.1 million, respectively, for the same period in 2017.	(6) Property, Plant, and Equipment Property, plant, and equipment consists of: (in thousands) December 31, December 31, Buildings and land $ 579 $ 556 Enterprise hardware and software 1,744 1,532 Leaseholds 1,705 1,504 Equipment 971 940 Furniture 175 354 Property, plant and equipment, gross 5,174 4,886 Accumulated depreciation (3,876 ) (3,803 ) Property, plant and equipment, net $ 1,298 $ 1,083 Depreciation expense for the years ended December 31, 2017, 2016 and 2015 was $0.3 million, $0.3 million, $0.6 million, respectively.

Accrued Expenses

Accrued Expenses	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Accrued Expenses	(5) Accrued Expenses Accrued expenses consist of the following: (in thousands) June 30, 2018 December 31, 2017 Compensation, excluding taxes $ 1,573 $ 869 Clinical trial expenses 2,304 1,124 Professional fees 314 221 Short-term portion of lease restructuring 193 209 Other 1 836 985 Total accrued expenses $ 5,220 $ 3,408 1 Other consists of various accrued expenses, with no individual item accounting for more than 5% of current liabilities at June 30, 2018 and December 31, 2017.	(7) Current Accrued Expenses Current accrued expenses include the following: (in thousands) December 31, December 31, Clinical trial expenses $ 869 $ 1,365 Compensation, excluding taxes 1,124 933 Professional fees 221 286 Short-term portion of lease restructuring 209 216 Other 1 985 607 Total accrued expenses $ 3,408 $ 3,407 1 Other consists of various accrued expenses, with no individual item accounting for more than 5% of current liabilities at December 31, 2017 and 2016.

Restructuring Expenses

Restructuring Expenses	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Restructuring Expenses	(6) Restructuring Expenses In order to help reduce operating costs and more appropriately align its office space with the size of its workforce, the Company entered into two sub-leases sub-lease (“Sub-lease one-half sub-lease (“Sub-lease one-half The following table provides the year-to-date (in thousands) Lease Liability Reserve balance at December 31, 2017 $ 604 Charges — Payments/Utilizations (109 ) Reserve balance at June 30, 2018 $ 495	(8) Restructuring Expenses In order to help reduce operating costs and more appropriately align its office space with the reduced size of its workforce, the Company entered into two sub-leases for a sub-lease agreement (“Sub-lease #1”) approximately one-half of sub-lease agreement (“Sub-lease #2”) remaining one-half of Other non-current liabilities The following table provides the year-to-date activity (in thousands) Lease Liability Reserve balance at December 31, 2016 $ 820 Charges — Payments/Utilizations (216 ) Reserve balance at December 31, 2017 $ 604

Secured Convertible Notes Payab

Secured Convertible Notes Payable and Common Stock Purchase Warrants	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Debt Disclosure Abstract
Secured Convertible Notes Payable and Common Stock Purchase Warrants	(7) Secured Convertible Notes Payable and Common Stock Purchase Warrants On June 4, 2018, the Company entered into a Securities Purchase Agreement (the “SPA”) with an institutional investor pursuant to which the Company issued $3.3 million in principal face amount of senior secured convertible notes of the Company (the “Notes”) and related Series D Warrants (the “Series D Warrants”) to purchase additional shares of the Company’s common stock (“Common Stock”). Notes in the amount of $3.3 million were issued for cash proceeds of $2.4 million with an original issue discount in the amount of $1.1 million. The Notes are secured pursuant to a Security Agreement which creates a first priority security interest in all of the personal property (other than Excluded Collateral (as defined in the Security Agreement) of the Company of every kind and description, tangible or intangible, whether currently owned and existing or created or acquired in the future. The Notes bear 8% interest payable quarterly in cash. Of the $3.3 million in issued Notes, $2.5 million matures in six months; the balance of $0.8 million is payable in twelve installments beginning seven (7) months after the original issuance date. Each payment shall be paid in cash or, provided that the Market Price (as defined in the SPA) is at least the conversion price of $3.00, at the option of the Company, upon ten (10) Trading Days’ written notice to the Holder, in free trading Common Stock at the conversion price. In connection with the issuance of the Notes under the SPA, the Company also issued Series D Warrants. Warrant D-1 D-2 101-113 pre-funded D-2 Warrant D-1 Warrant D-2 Expected life (in years) 5.0 5.5 - 6.5 Expected volatility 194.10% 215.0% - 389.0% Risk-free interest rates 2.78% 2.13% - 2.30% The Company recognized a discount to debt of $2.3 million and additional expense of $2.8 million related to the initial fair value of the Series D Warrants. The D-1 D-2 D-2-101	(9) Convertible Notes Payable As of December 31, 2017, the senior secured convertible notes (the “Notes”) had been repaid in full and were no longer outstanding. On June 6, 2016, the Company entered into a Securities Purchase Agreement (the “SPA”) with certain investors named on the Schedule of Buyers attached to the SPA pursuant to which the Company issued $35.0 million in principal face amount of Notes and related Series C Warrants (the “Series C Warrants”) to purchase additional shares of the Company’s common stock, par value $0.01 per share (“Common Stock”). $35.0 million of the Notes were issued for cash proceeds of $32.2 million with an original issue discount in the amount of $2.8 million. The Notes were secured pursuant to a Security Agreement which creates a first priority security interest in all of the personal property (other than Excluded Collateral (as defined in the Security Agreement) of the Company of every kind and description, tangible or intangible, whether currently owned and existing or created or acquired in the future. Under the terms of the Notes, at closing the Company received an initial tranche of $3.0 million for immediate use for general corporate purposes. A second tranche of $3.0 million was released to the Company in December 2016. The balance was released throughout 2017. In connection with the issuance of the Notes under the SPA, the Company also issued Series C Warrants, exercisable to acquire approximately 40 shares of Common Stock. The provisions in the Series C Warrants required the Company to account for the warrants as derivative liabilities. The Company recognized a discount to debt of $27.8 million related to the initial fair value of the Series C Warrants. On April 2, 2017 the Company entered into separate warrant repurchase agreements (the “Warrant Repurchase Agreements”) with each of the investors named on the Schedule of Buyers attached to the SPA. Pursuant to the Warrant Repurchase Agreements, each investor agreed to a Controlled Account Release, in an aggregate amount equal to $7.9 million, which funds in each case were paid to the respective investor, in exchange for cancellation of the Warrants issued to each investor under the SPA. As a result of the extinguishment, the Company recognized a gain of $9.6 million, representing the difference between the fair value of the liability as of the extinguishment date of $17.5 million related to the Series C Warrants and the $7.9 million in cash returned to the Note holders to extinguish the liability. The Company had agreed to make amortization payments with respect to the Notes in fourteen (14) equal installments beginning seven (7) months after the original date of issuance of June 13, 2016 (each, an “Installment Date”). On each installment date, assuming certain equity conditions were met, the installment payment was, at the election of the Company, automatically converted into shares of Common Stock at a conversion rate defined in the SPA. If the Company could not meet the equity conditions, it would have been required to repay some or all of the amounts due under the notes in cash. At any time after the issuance of the Notes, the Notes were convertible at the election of the holder into shares of our Common Stock at a conversion price equal to $8,537,775, subject to adjustment as provided in the Notes. As a result of the Notes including a feature such that the conversion price is based upon a formula which includes discounts to the market price of the common stock as well as having a lower effective conversion price considering the issuance discount and the value allocated to the Series C Warrants, the Company has recognized a beneficial conversion feature of $4.4 million. The original issue discount, the beneficial conversion feature, and the fair value of the issuance of the Series C Warrants are collectively considered the debt discount. The Company recorded a debt discount in the amount of $35.0 million which was being amortized over the life of the Notes using the effective interest method. As of December 31, 2017, $35.0 million of the debt discount has been amortized to interest expense. All debt issuance costs were accounted for as a deferred asset and were amortized over the life of the Notes. As of December 31, 2017, the Company had incurred approximately $2.2 million in debt issuance costs all of which were amortized or expensed as of December 31, 2017. Restructuring Agreement On August 28, 2017, the Company entered into a Restructuring Agreement (the “Agreement”) with one of the institutional investors (the “Investor”) who was a party to the SPA. As of the date the Agreement was entered into, the Investor held $11,444,637 aggregate principal amount of Notes of which there was $10,092,857 aggregate Restricted Principal, (as defined in the Notes) of Notes (the “Restricted Notes”), secured by such aggregate cash amount held in a collateral account of the Company in the same amount (the “Restricted Cash”) and (y) $1,351,780 principal of Notes (the “Unrestricted Notes”), (ii) 4,200 shares of Series A Preferred Stock and (iii) 2,006 shares of Series B Convertible Preferred Stock. Pursuant to the Agreement, (a) on the date thereof the Company and the Investor took the following actions (the “Initial Restructuring”): (i) the Investor released restrictions on $1,650,000 of Restricted Cash (the “Initial Release”), (ii) the Investor consented to the use of additional Restricted Cash to effect redemptions of the Series A Preferred Shares and the Series B Preferred Shares, (iii) the Investor cancelled $1,200,000 aggregate principal of the Notes (such portion of the Notes, the “Cancellation Note”), (iv) the Company redeemed all the Series A Preferred Shares outstanding for a cash payment to the Investor of $4.20 and (v) the Company redeemed the Series B Preferred Shares for a cash payment to the Investor of $2,006,000 and (b) upon the consummation of a reverse stock split of our Common Stock of at least twenty to one (the “Reverse Stock Split Event”, and such date, the “Reverse Stock Split Date”) by September 15, 2017, the Company and the Investor shall have taken the following actions (the “Additional Restructuring”, and together with the Initial Restructuring, the “Restructuring”): (i) the Investor shall consent to the use of Restricted Cash to effect redemptions of $4,000,000 aggregate Restricted Principal of the Restricted Notes (such portion of the Restricted Notes, the “Redemption Notes”), (ii) the Company shall redeem the Redemption Notes for a redemption price of $6,436,852.80 (the “Redemption Price”) and (iii) the Company shall exchange (the “Exchange”), pursuant to Section 4(a)(2) of the Securities Act of 1933, as amended, $2,436,852.80 aggregate Restricted Principal of the Restricted Notes (such portion of the Restricted Notes, the “Exchange Notes”, and together with the Redemption Notes, the “Restructured Notes”) for new warrants to purchase 114,286 shares of its Common Stock (the “New Warrants”, as exercised, the “New Warrant Shares”). The New Warrants expire on the 42 month anniversary of the date of issuance and bear an exercise price of $61,250 per share (which shall be adjusted to the new lower purchase price per share if there is a subsequent “down round” financing). The Investor, in lieu of an exercise of the New Warrants pursuant to a cash payment of the aggregate exercise price of the number of New Warrants being exercised, may exercise the New Warrants, in whole or in part, by electing instead to receive upon such exercise two shares and one hundred and twenty-five thousandths of a share of the Company’s Common Stock for each Warrant Share exercised pursuant to this provision. The transactions set forth herein were being made in reliance upon the exemption from registration provided by Rule 4(a)(2) of the Securities Act of 1933, as amended (the “1933 Act”) and Rule 144(d)(3)(ii) of the 1933 Act. As a result of not having effected a reverse stock split by September 15, 2017, the Additional Restructuring did not occur. This transaction was accounted for as a debt settlement that resulted in extinguishment. As such, the $1.9 million difference between the fair value of the common shares issued and the $1.2 million debt settlement was recorded as a loss on debt settlement. Amendment to Restructuring Agreement As a result of the lack of requisite approval by Delcath stockholders for the Company’s proposed reverse stock split, the parties and the two investors in the Notes entered into an amendment to the August restructuring agreement on October 10, 2017 as follows: (i) on the date that the Company effects a reverse split of its common stock, (x) the Company will exchange, pursuant to Section 4(a)(2) of the Securities Act of 1933, as amended, an aggregate principal amount of those notes equal to $279,015 for new warrants to purchase an aggregate of 127,551 shares of Common Stock, and the Company shall redeem all the Series C Preferred Shares then outstanding for a cash payment of $590,000 and (ii) upon the initial consummation, on or prior to December 15, 2017, by the Company of the offering contemplated by the registration statement on Form S-1 that th an S-1 offering November 2017 Exchange Agreement On November 15, 2017, the Company entered into exchange agreements (“Exchange Agreement”) with each of the two investors from its June 2016 private placement of senior secured convertible notes as contemplated by the SPA. As of November 15, 2017, those investors held $11,157,970 aggregate principal amount of Notes. On November 15, 2017, the Company authorized a new series of senior secured convertible notes of the Company, in the aggregate original principal amount as set forth above (the “Exchange Notes”), which Exchange Notes convertible into shares of Common Stock in accordance with the terms of the Exchange Notes. Subject to the terms and conditions of the Exchange Agreements, the Company and the investors exchanged for (a) $10,562,425 aggregate principal amount of the Exchange Notes (the “New Notes”, and the shares of Common Stock issuable pursuant to the terms of the New Notes, including, without limitation, upon conversion or otherwise, collectively, the “New Conversion Shares”) and (b) warrants to purchase an aggregate of 14,000 shares of Common Stock at an initial exercise price of $1,225. The warrants have a five year term. The New Notes had the following terms: • The initial conversion price was $750.00 per share for an optional conversion and at any time, an investor could have instead engaged in an alternate conversion for which the conversion price was 82% (75% if an event of default) of the lowest volume weighted average price for the Company’s common stock on the three trading days prior to and including the date of the conversion. • The obligation to prepay the New Notes was extended to March 31, 2018, except in the case of an event of default or change in control. • Assuming equity conditions as stated in the New Notes are met, the investors consented to release cash to the Company from the existing controlled accounts upon conversion of the New Notes. The November Exchange Agreement was accounted for as an extinguishment. As such, the New Notes were recorded at their calculated fair value of $15.2 million, the related November 2017 Warrants were recorded as a derivative liability at their calculated fair value of $14.4 million and the difference between the fair value of the New Notes, the fair value of the warrants issued, and the carrying amount of the old notes was recorded as a $19.0 million loss on extinguishment. As with the Notes issued in June 2016, the New Notes also contained a beneficial conversation feature. The value of this feature was considered in the fair value calculations of the New Notes and was determined to be $4.9 million of the $15.2 million total fair value. The $10.3 million fair value of the New Notes was accreted up to the face value of $10.6 million over the term of the New Notes with the $0.3 million difference charged to interest expense. The $4.9 million beneficial conversion feature was fully credited to Additional paid-in capital December 28, 2017 Exchange Agreements On December 28, 2017, the Company entered into exchange agreements (“Exchange Agreements”), with each of the two investors from its June 2016 private placement of senior secured convertible notes (as further exchanged, the “Notes”) originally issued pursuant the SPA. Pursuant to the Exchange Agreements, the Company (i) extinguished its remaining $3,027,408 in outstanding obligations under the New Notes in full, (ii) obtained a release of restrictions on $2,046,898 in restricted cash held in its control accounts, (iii) issued to the investors 29,600 shares (the “Shares”) of its common stock and rights (“Rights”) to receive 217,800 shares of common stock to the extent such issuance of Shares would otherwise result in the beneficial ownership by any such investor of more than 4.9% or 9.9% of its issued and outstanding stock), as applicable, for an aggregate of 247,417 shares of its common stock (in each case, subject to trading restrictions set forth in leak out agreements the Company separately entered into with each) and (iv) a cash payment to the investors of $829,831 from the restricted cash held in the control accounts. The 29,600 shares were issued and outstanding at December 31, 2017. The rights were fully exercised in January 2018. This transaction resulted in the settlement of $3.0 million in debt. The $3.7 million difference between the fair value of the shares and rights issued for shares and the carrying value of the Notes was recorded as a loss on debt settlement. The Company has issued shares of Common Stock and Preferred Stock as payments of principal (including certain early repayments at the option of the holders) and effected a retirement under the Notes and New Notes as follows: Number of Number of Applicable Reduction in January 12, 2017 23 — $ 63,000.00 $ 1,478,318 January 26 - February 1, 2017 1 10 — $ 56,000.00 $ 544,000 February 10, 2017 87 — $ 35,000.00 $ 3,045,817 February 23 - March 2, 2017 1 5 — $ 24,500.00 $ 125,999 March 13, 2017 229 — $ 19,250.00 $ 4,417,829 April 10, 2017 344 — $ 10,500.00 $ 3,621,286 May 9, 2017 218 — $ 8,750.00 $ 1,913,915 June 7 / July 2, 2017 Exchange Agreement 2 1,380 4,200 $ 12,250.00 $ 4,200,000 July 7, 2017 229 — $ 12,250.00 $ 2,000,000 August 4, 2017 83 — $ 5,250.00 $ 1,015,848 August 28, 2017 Restructuring Agreement 3 229 — $ 5,250.00 $ 1,200,000 November 6, 2017 Warrant Exchange 4 — — $ — $ 279,016 November 15, 2017 Exchange Agreements 5 194,896 — $ 41.72 $ 8,130,564 Retirement per December 28, 2017 Exchange Agreements 6 — — $ — $ 553,234 December 28, 2017 Exchange Agreements 6 445,152 — $ 10.00 $ 2,474,174 Total 642,885 $ 35,000,000 1 During the periods referenced above, the Company and the holders of the Notes agreed to a temporary reduction in the conversion price in order to encourage voluntary conversion of Notes by the holders thereof. 2 On July 2, 2017, the Company entered into an exchange agreement with one of its investors which had purchased Notes, for $4.2 million aggregate principal amount of such Notes for 4,200 shares of Series A Preferred Stock. The Series A Preferred Stock shares were issued to address a short-term valuation issue for 1,380 common shares delivered to the Notes holders to close an installment period. Through the Series A Preferred Shares placement, the Company was able to value the open installment shares such that the amount of debt remaining under the Notes was reduced by $4.2 million. Additionally, the Company recognized a loss on debt settlement of $1.0 million related to this transaction. 3 On August 28, 2017, the Company entered into a restructuring agreement with one of its investors which had purchased Notes. The restructuring agreement included a provision to exchange 229 shares for $1.2 million aggregate principal amount of such Notes. Additionally, the Company recognized a loss on debt settlement of $1.9 million related to this transaction. 4 On October 10, 2017, the Company entered into an amendment to the August 28, 2017 Restructuring Agreement which included a provision to exchange debt for the issuance of warrants. Additionally, the Company recognized a loss on debt extinguishment of $2.3 million. 5 On November 15, 2017, the Company entered into an exchange agreement which included a provision to exchange 1,948 shares for $0.6 million aggregate principal amount of such Notes. Additionally, the Company issued 192,948 million shares for $7.5 million aggregate principal amount of Notes under the updated conversion price formula as discussed in more detail above. Additionally, the Company recognized a loss on debt extinguishment of $21.0 million in connection with the issuance of the New Notes and warrants as part of such exchange. 6 On December 28, 2017, the Company entered into an exchange agreement to retire $0.6 million aggregate principal amount of Notes and to issue 247,417 million shares and rights for shares for the remaining $2.5 million aggregate principal amount of Notes. Additionally, the Company recognized a loss on debt extinguishment of $3.7 million.

Stockholders' Equity

Stockholders' Equity	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Stockholders Equity Note Abstract
Stockholders' Equity	(8) Stockholders’ Equity Stock Issuances Reverse Stock Split On May 2, 2018, the Company effected a reverse stock split at which time Delcath’s common stock began trading on the OTCQB on a one-for-five one-for-five 10-Q February 2018 Financing In February 2018, the Company completed the sale of 424,000 shares of its common stock, 76,000 pre-funded Stock Incentive Plans As a result of the May 2, 2018 reverse stock split, the Company’s Stock Incentive Plans has no active grants and no further shares available to be granted. For the three and six months ended June 30, 2018, the Company recognized compensation income of $47,000 and $40,000 relating to stock options granted to employees. For the same period in 2017, the Company recognized compensation expense of approximately $24,000 and $46,000 respectively. For the three and six months ended June 30, 2018, the Company recognized compensation income of $94,000 and $81,000 relating to restricted stock granted to employees. For the same period in 2017, the Company recognized compensation expense of approximately $6,000 and $100,000, respectively.	(10) Stockholders’ Equity Reverse Stock Split On November 6, 2017, the Company effected a reverse stock split at which time Delcath’s common stock began trading on the OTCQB on a one-for-three hundred theone-for-three hundred Form 10-K and On July 19, 2016, shareholders of the Company approved, through a shareholder vote, an amendment to the Company’s Amended and Restated Certificate of Incorporation authorizing the Board of Directors to effect a reverse stock split of Delcath’s common stock at a ratio within a range of one-for-ten (1:10) to one-for-twenty (1:20). a one-for-sixteen (1:16) the one-for-sixteen exchange Form 10-K and In addition, shareholders of the Company also approved an amendment to the Company’s Amended and Restated Certificate of Incorporation to increase the number of authorized shares of common stock from 170,000,000 to 500,000,000. The previously discussed reverse stock split had no impact on the increase in authorized shares. Preferred Stock Issuances Series A Preferred Stock On June 29, 2017, the Company’s Board authorized the establishment of a new series of preferred stock designated as Series A Preferred Stock, $0.01 par value, the terms of which are set forth in the certificate of designations for such series of Preferred Stock (the “Series A Certificate of Designations”) which was filed with the State of Delaware on June 30, 2017 (together with any preferred shares issued in replacement thereof in accordance with the terms thereof, the “Series A Preferred Stock”). On July 2, 2017, the Company entered into an exchange agreement (the “Exchange”) with one of its investors which had purchased the Notes of $4.2 million aggregate principal amount of such Notes for 4,200 shares of Series A Preferred Stock (the “Series A Preferred Shares”). The Exchange was made in reliance upon the exemption from registration provided by Rule 3(a)(9) of the Securities Act of 1933, as amended. The Series A Preferred Shares were entitled to the whole number of votes equal to $4.2 million divided by $644,000.00 (the closing bid price on June 13, 2016, the date of issuance of the Notes) or 7 votes. The Series A Preferred Stock had no dividend, liquidation or other preferential rights to the Company’s common stock, and each share of Series A Preferred Stock was redeemed for the amount of $0.001, paid in cash pursuant to the Restructuring Agreement signed on August 28, 2017 and discussed in further detail in Note 9. Series B Preferred Stock On June 29, 2017, the Company’s Board authorized the establishment of a new series of preferred stock designated as Series B Preferred Stock, $0.01 par value, the terms of which are set forth in the certificate of designations for such series of Preferred Stock (the “Series B Certificate of Designations”) which was filed with the State of Delaware on June 30, 2017 (together with any preferred shares issued in replacement thereof in accordance with the terms thereof, the “Series B Preferred Stock”). On July 11, 2017, the Company entered into a securities purchase agreement with existing holders of Notes pursuant to which the investors purchased $2,360,000 of Series B Preferred Stock for a cash purchase price of $2,000,000 in a private placement. The Series B Preferred Stock was entitled to the whole number of votes equal to $2.0 million divided by $32,787 (the closing bid price on July 5, 2017, the date of the original securities purchase agreement for the Series B Preferred Stock), or 61 votes. The Series B Preferred Stock had no liquidation or other preferential rights (but had the redemption rights described below) to the Company’s common stock and could have been converted into shares of common stock at a price equal to $26,775 per share upon the earlier of the date of closing to the extent that the holder thereof reallocated shares of our common stock reserved for issuance under its Notes to conversion of the Series B Preferred Shares and otherwise upon receipt of shareholder approval of the Reverse Stock Split. The Series B Preferred Stock allowed for optional redemption by the Company at any time after issuance or the holders at any time after the tenth business day prior to the maturity date. In the instance of a Financing, the Company was required to redeem the Series B Preferred Stock. The $360,000 difference between the redemption amount and the cash purchase price of the Series B Preferred Stock, as well as all issuance costs related to the Series B Preferred Stock, have been recorded as a deemed dividend. The Series B Preferred Stock was redeemed for $2,360,000 pursuant to the Restructuring Agreement signed on August 28, 2017 with one investor and upon a redemption notice from the second investor as discussed in further detail in Note 9. Series C Preferred Stock On September 12, 2017, the Company’s Board authorized the establishment of a new series of preferred stock designated as Series C Preferred Stock, $0.01 par value, the terms of which are set forth in the certificate of designations for such series of Preferred Stock which was filed with the State of Delaware on September 20, 2017. On September 21, 2017, the Company entered into a securities purchase agreement with the two investors which had purchased Notes of $0.5 million aggregate purchase price for 590 shares of Series C Preferred Stock. The purchase of the Series C Preferred Stock is being made in reliance upon the exemption from registration provided by Rule 4(a)(2) of the Securities Act of 1933, as amended. The Series C Preferred Stock shall be entitled to 2,968 votes and may only vote on approval of a reverse split of our outstanding common stock. The Series C Preferred Stock has no dividend, liquidation or other preferential rights to the Company’s common stock, and each share of Series C Preferred Stock shall be redeemable for the amount of $1,000.00, payable in cash per share at our written election, and must be redeemed no later than December 21, 2017. Because the Series C Preferred Stock was mandatorily redeemable, it has been recorded as a liability with the difference between the purchases price and the fair value being recognized over the term of the instrument. Additionally, all expenses related to the issuance of the Series C Preferred Stock are recognized as a debt discount and have been amortized over the term of the instrument. Per the terms of the October 22, 2017 Amendment to the Restructuring Agreement, the Series C Preferred Stock was redeemed for $590,000 on November 6, 2017. Stock and Warrant Issuances In October 2013, the Company completed the sale of 1 share of its common stock and the issuance of warrants to purchase approximately 9 common shares (the “2013 Warrants”) pursuant to a placement agency agreement. The Company received proceeds of $7.5 million, with net cash proceeds after related expenses from this transaction of approximately $6.9 million. Of those proceeds, the Company allocated an estimated fair value of $1.9 million to the 2013 Warrants. The exercise price is subject to appropriate adjustment in the event of stock dividends, stock splits, reorganizations or similar events affecting our common stock. At December 31, 2017, the 2013 Warrants were exercisable at $19,712,000 per share with 9 warrants outstanding. The 2013 Warrants have a five-year term. In February 2015, the Company completed the sale of 1 share of its common stock and the issuance of warrants to purchase 9 common shares (the “February 2015 Warrants”) pursuant to an underwriting agreement. The Company received proceeds of $2.6 million, with net cash proceeds after related expenses from this transaction of $2.5 million. Of those proceeds, the Company allocated an estimated fair value of $0.8 million to the February 2015 Warrants. The exercise price is subject to appropriate adjustment in the event of stock dividends, stock splits, reorganizations or similar events affecting our common stock. The exercise price of the warrants is also subject to anti-dilution adjustments for any issuance of common stock or rights to acquire common stock for consideration per share less than the exercise price of the warrants. At December 31, 2017, the February 2015 Warrants were exercisable at $24,500 per share with approximately 9 warrants outstanding. The February 2015 Warrants have a five-year term. In July 2015, the Company completed the sale of approximately 3 Units consisting of 3 shares of its common stock, Series A Warrants to purchase up to approximately 8 common shares (“Series A Warrants”) and Series B Warrants to purchase Units consisting of up to approximately 3 common shares (“Series B Warrants”) and 8 Series A Warrants pursuant to an underwriting agreement. The Company received proceeds of $7.0 million, with net cash proceeds after related expenses from this transaction of $6.0 million. Of those proceeds the Company allocated an estimated fair value of $3.4 million to the Series A and Series B Warrants. During the year ended December 31, 2016, approximately 1 Series B Warrant was exercised for net proceeds of approximately $0.8 million. The remaining 3 Series B Warrants expired on January 29, 2016 and the related liability was credited to Change in the fair value of the warrant liability. As a result of the Series B Warrant exercises, an additional 1 Series A Warrant was issued. The exercise price of the Series A Warrants is subject to appropriate adjustment in the event of stock dividends, stock splits, reorganizations or similar events affecting our common stock and is subject to anti-dilution adjustments for any issuance of common stock or rights to acquire common stock for consideration per share less than the exercise price of the warrants. At December 31, 2017, the July 2015 Series A Warrants were exercisable at $24,500 with approximately 9 warrants outstanding. The Series A Warrants have a five-year term. There was approximately 1 July 2015 Series A Warrant exercised during the year ended December 31, 2017 for proceeds of approximately $15,000. There was approximately 1 July 2015 Series A Warrants exercised during the year ended December 31, 2016 for proceeds of $0.4 million. In June 2016, the Company entered into a SPA pursuant to which the Company issued $35.0 million in principal face amount of the Notes and related Series C Warrants to purchase 40 additional shares of the Company’s common stock. The Company allocated an estimated fair value of $27.8 million to the Series C Warrants. Pursuant to the Warrant Repurchase Agreements, each investor agreed to a Controlled Account Release, in an aggregate amount equal to $7.9 million, which funds in each case are to be paid to the respective investor, in exchange for cancellation of the Series C Warrants issued to each investor under the SPA. During 2017, 224,000 common shares and rights to receive 217,800 common shares were issued to satisfy the Notes. In October 2016, the Company completed the sale of 2 shares of its common stock and the issuance of warrants to purchase 1 common share (the “October 2016 Warrants”) pursuant to an underwriting agreement. The Company received proceeds of $1.2 million, with net cash proceeds after related expenses from this transaction of $1.1 million. Of those proceeds, the Company allocated an estimated fair value of $0.3 million to the October 2016 Warrants. The exercise price is subject to appropriate adjustment in the event of stock dividends, stock splits, reorganizations or similar events affecting our common stock. The exercise price of the warrants is also subject to anti-dilution adjustments for any issuance of common stock or rights to acquire common stock for consideration per share less than the exercise price of the warrants. For purposes of these adjustments, dilutive issuances do not include securities issued under existing instruments, under board-approved equity incentive plans or in certain strategic transactions. At December 31, 2017, the October 2016 Warrants were exercisable at $24,500 per share with 1 warrant outstanding. The October 2016 Warrants have a five-year term. There was 1 October 2016 Series C Warrants exercised during the year ended December 31, 2016 for proceeds of $0.1 million. Pursuant to the October 10, 2017 Amendment to the Restructuring Agreement, 225 warrants were issued to each of the two investors from the June 2016 SPA on November 6, 2017 following the effectuation of the reverse stock split discussed earlier. The warrants contain a cashless exercise provision that allows the holders to exercise each warrant for three shares of common stock. The warrants have a 4.5 year term and an exercise price of $61,250. The exercise price is subject to appropriate adjustment in the event of stock dividends, stock splits, reorganizations or similar events affecting our common stock. The exercise price of the warrants is also subject to anti-dilution adjustments for any issuance of common stock or rights to acquire common stock for consideration per share less than the exercise price of the warrants. For purposes of these adjustments, dilutive issuances do not include securities issued under existing instruments, under board-approved equity incentive plans or in certain strategic transactions. As of December 31, 2017, 255 warrants have been exercised resulting in the issuance of 735 common shares. 10 warrants remain outstanding at December 31, 2017. In November 2017, the Company issued 14,049 warrants pursuant to an Exchange Agreement entered into with each of the two investors from the June 2016 SPA. The Company allocated an estimated fair value of $14.4 million to the November 2017 Warrants. The exercise price is subject to adjustment in the event of stock dividends, stock splits, reorganizations or similar events affecting our common stock. The exercise price of the warrants is also subject to anti-dilution adjustments for any issuance of common stock or rights to acquire common stock for consideration per share less than the exercise price of the warrants. For purposes of these adjustments, dilutive issuances do not include securities issued under existing instruments, under board-approved equity incentive plans or in certain strategic transactions. At December 31, 2017, the November 2017 Warrants were exercisable at $1,225 per share with 14,049 warrants outstanding. The November 2017 Warrants have a five-year term from the date of exercisability. In October 2015, the Company filed a registration statement on Form S-3 with Form S-3. Stock Incentive Plans The Company established the 2004 Stock Incentive Plan and the 2009 Stock Incentive Plan (collectively, the “Plans”) under which 0 and 0 shares, respectively, have been reserved for the issuance of stock options, stock appreciation rights, restricted stock, stock grants and other equity awards. In July 2016, the total number of shares of Delcath common stock reserved for issuance under the 2009 Stock Incentive Plan was increased by 0 shares, from 0 to 0 shares, upon a favorable vote by the Company’s stockholders. The Plans are administered by the Compensation and Stock Option Committee of the Board of Directors which determines the individuals to whom awards shall be granted as well as the type, terms, conditions, option price and the duration of each award. As of December 31, 2017, there were 0 shares available to grant under the 2009 Stock Incentive Plan. A stock option grant allows the holder of the option to purchase a share of the Company’s common stock in the future at a stated price. Options and Restricted Stock granted under the Plans vest as determined by the Company’s Compensation and Stock Option Committee. Options granted under the Plans expire over varying terms, but not more than ten years from the date of grant. Stock option activity for 2017, 2016 and 2015 is as follows: Stock Option Activity under the Plans (1) Stock Exercise Price per Weighted Average Weighted Average Outstanding at December 31, 2014 0 $ 0 - $0 $ 0 0 Granted 0 0 0 0 Forfeited (0 ) 0-0 0 0 Outstanding at December 31, 2015 0 $ 0 - $0 $ 0 0 Granted — — — Forfeited (0 ) 0-0 0 0 Outstanding at December 31, 2016 0 $ 0 - $0 $ 0 0 Granted 0 $ 0 $ 0 0 Forfeited (0 ) $ 0 $ 0 0 Outstanding at December 31, 2017 0 $ 0 - $0 $ 0 0 Exercisable at December 31, 2017 0 $ 0 - $0 $ 0 0 (1) Due to the May 2, 2018 1-for-500 reverse stock split, and no fractional shares being issued, all numbers are reduced to zero. For the years ended December 31, 2017, 2016 and 2015 the Company recognized compensation expense related to stock option grants of approximately $0.1 million, $0.2 million and $0.3 million, respectively. The estimated fair value of each option award granted was determined on the date of grant using an option pricing model with the following assumptions for option grants made in 2017 and 2015. There were no option grants during 2016. Year ended Year ended 2017 2015 Weighted average risk-free interest rates 2.15 % 1.82 % Weighted average expected volatility 170.42 % 97.70 % Dividend yield — — Weighted average expected option term (in years) 7.29 5.15 Weighted average grant date fair value $ 82.34 $ 4,964.73 No dividend yield was assumed because the Company has never paid a cash dividend on its common stock and does not expect to pay dividends in the foreseeable future. Volatilities were developed using the Company’s historical volatility. The risk-free interest rate was developed using the U.S. Treasury yield for periods equal to the expected life of the stock options on the grant date. The expected option term is based on actual historical results. A summary of the Company’s non-vested options Non-Vested Options (1) Number of Weighted Non-vested at 0 $ 0 Granted — — Vested (0 ) 0 Forfeited (0 ) 0 Non-vested at 0 $ 0 Granted 0 0 Vested (0 ) 0 Forfeited (0 ) 0 Non-vested at 0 $ 0 Additional compensation expense of approximately $6,800, relating to the unvested portion of stock options granted, is expected to be recognized over a remaining average period of 0.42 years. The aggregate intrinsic value of options outstanding and options exercisable at December 31, 2017 is $0. The aggregate intrinsic value represents the total pretax intrinsic value, based on options with an exercise price less than the Company’s closing stock price of $450.00 as of December 31, 2017, which would have been received by the option holders had those option holders exercised their options as of that date. A summary of the Company’s restricted stock activity as of December 31, 2017 and changes during the years ended December 31, 2017 and December 31, 2016 are presented below: Restricted Stock Activity (1) Number of Weighted Non-vested at — $ — Granted — — Vested — — Forfeited — — Non-vested at — $ — Granted — — Vested — — Forfeited — — Non-vested at — $ — For the three years ended December 31, 2017, 2016 and 2015 the Company recognized compensation expense related to restricted stock grants of approximately $0.1 million, $0.3 million and $0.3 million, respectively. (1) Due to the May 2, 2018 1-for-500 reverse stock split, and no fractional shares being issued, all numbers are reduced to zero. Warrants The Company issued warrants as part of its offerings in 2013, 2015, and 2016 as well as part of its issuance of convertible notes in 2016 and an exchange agreement in 2017. A summary of warrant activity is as follows: Warrants Exercise Price Weighted Weighted Outstanding at January 1, 2014 9 $ 4,900,000-$19,712,000 $ 15,170,879 2.78 Issued 35 2,240,000 Exercised (- ) 2,296,000 Expired (- ) 2,296,000 Outstanding at December 31, 2015 44 $ 2,072,000-19,712,000 $ 44,858,633 2.16 Issued 30 840,000 Exercised (3 ) 481,250 Expired (3 ) 994,000 Outstanding at December 31, 2016 78 $ 281,750-$19,712,000 $ 910,000 5.59 Issued 14,256 2,299 Exercised (246 ) 4,221 Expired (39 ) 845,250 Outstanding at December 31, 2017 14,049 $ 1,225-19,712,000 $ 1,569 4.88

Fair Value Measurements

Fair Value Measurements	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	(9) Fair Value Measurements Derivative Warrant Liability For the three and six months ended June 30, 2018, the Company recorded derivative warrant expense of $2.5 million and $17.2 million, respectively. The resulting derivative warrant liabilities totaled $6.9 million at June 30, 2018. Management expects that the Warrants will either be exercised or expire worthless. The fair value of the Warrants at June 30, 2018 and December 31, 2017 was determined by using option pricing models with the following assumptions: June 30, 2018 December 31, 2017 Expected life (in years) 0.33 - 6.40 0.82 - 4.88 Expected volatility 132.69% - 372.0% 130.88% - 266.92% Risk-free interest rates 1.99% -2.92% 1.68% - 2.06% The table below presents the Company’s assets and liabilities measured at fair value on a recurring basis as of June 30, 2018, aggregated by the level in the fair value hierarchy within which those measurements fall in accordance with ASC 820. Assets and Liabilities Measured at Fair Value on (in thousands) Level 1 Level 2 Level 3 Balance at June 30, 2018 Liabilities Derivative instrument liabilities $ — $ — $ 6,883 $ 6,883 For the periods ended June 30, 2018 and 2017, there were no transfers in or out of Level 1, 2 or 3 inputs. The table below presents the activity within Level 3 of the fair value hierarchy for the six months ended June 30, 2018: Fair Value Measurements Using Significant Unobservable Inputs (Level 3) (in thousands) Warrant Balance at December 31, 2017 $ 560 Fair value of warrants issued 23,532 Fair value of warrants exercised — Total change in the liability included in earnings (17,209 ) Balance at June 30, 2018 $ 6,883	(11) Fair Value Measurements Derivative Financial Instruments As disclosed in Note 10 of the Company’s consolidated financial statements contained in this Annual Report on Form 10-K, the Form 10-K. The (ASC 820-10). The ASC 820-10, while For the year ended December 31, 2017, the Company recorded pre-tax derivative November October 2016 July 2015 February October 2013 Expected volatility 217.39 % 130.88 % 161.87 % 169.95 % 266.92 % Risk free interest rates 1.98 % 2.06 % 1.94 % 1.90 % 1.68 % Expected life (in years) 4.88 3.76 2.56 2.13 0.82 The table below presents the Company’s assets and liabilities measured at fair value on a recurring basis as of December 31, 2017 and 2016, aggregated by the level in the fair value hierarchy within which those measurements fall. Assets and Liabilities Measured at Fair Value on a Recurring Basis Assets and Liabilities Measured at Fair Value on a Recurring Basis Level 1 Level 2 Level 3 Balance at (in thousands) 2017 2016 2017 2016 2017 2016 2017 2016 Liabilities Derivative instrument liabilities $ — $ — $ — $ — $ 560 $ 18,751 $ 560 $ 18,751 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) (in thousands) Warrant Liability Balance at January 1, 2015 $ 225 Total change in the liability included in earnings (564 ) Fair value of warrants issued 4,247 Fair value of warrants exercised (123 ) Balance at December 31, 2015 3,785 Total change in the liability included in earnings (12,780 ) Fair value of warrants issued 28,472 Fair value of warrants exercised (726 ) Balance at December 31, 2016 $ 18,751 Total change in the liability included in earnings (15,103 ) Extinguishment of convertible note warrant (17,489 ) Fair value of warrants issued 16,953 Fair value of warrants exercised (2,552 ) Balance at December 31, 2017 $ 560

Commitments

Commitments	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments	(12) Commitments Operating Leases In February 2010, the Company entered into an agreement to lease (Initial Lease) 8,629 square feet of office space at 810 Seventh Avenue, New York, NY with an option to expand an additional 8,629 square feet. The term of the Initial Lease began in March, 2010. In September 2010, the Company exercised its option right under the Initial Lease and entered into an agreement to lease (Lease Amendment) an additional 8,629 square feet of office space. The term of the Lease Amendment began in January 2011 and will expire in March 2021. In addition, the Lease Amendment extends the term of the Initial Lease to March 2021. The Initial Lease and the Lease Amendment provide for annual rent of $996,000 in 2015, $1.0 million in 2016, and $1.1 million in 2017-2020. As discussed in Note 8, the Company has sub-leased this In August 2011, Delcath Systems Limited entered into an agreement of lease for an office and manufacturing facility located in the city of Galway, Ireland. This facility is approximately 19,200 square feet and is intended to be the location of Delcath’s European headquarters. The Lease is for a term of ten years, commencing August, 2011. The Lease provides for fixed annual lease amounts payable in advance in equal quarterly installments. The remaining annual lease amount is (USD conversion is based on the December 31, 2017 conversion rate):– €183,179 ($143,726). Delcath Limited is also required to pay for customary building operating expenses. Delcath Limited’s payment obligations and performance of the Lease are guaranteed by Delcath. The Company has sub-leased a In March 2016, the Company entered into a sub-lease agreement In October 2016, the Company entered into a lease agreement for 95-97 Park Future minimum lease payments, net of receipts due under the terms of subleases, under all operating leases at December 31, 2017 are as follows: (in thousands) Future Lease 2018 872 2019 501 2020 456 2021 281 2022 — 2023 — $ 2,110 For the years ended December 31, 2017, 2016, and 2015 rent expense totaled approximately $0.6 million, $0.5 million and $0.4 million, respectively. Letters of Credit Under the terms of the lease agreement for office space at 810 Seventh Avenue, New York, NY, the Company is required to maintain a letter of credit in the amount of $881,297 which will expire in February 2019 if not renewed by the Company. Under the terms of a sub-lease agreement

Income Taxes

Income Taxes	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	(11) Taxes As discussed in Note 13 Income Taxes The Company is subject to income tax in the U.S., as well as various state and international jurisdictions. During the third quarter of 2015, the Internal Revenue Service commenced an examination of the Company’s federal income tax return for the year ended December 31, 2013. The examination was completed in the third quarter of 2017 and no changes were made to the reported amounts. Accordingly, there was no effect on the financial statements as a result of the examination. 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 13 Income Taxes On December 22, 2017, the 2017 Tax Cuts and Jobs Act (the Tax Act) was enacted into law and the new legislation contains several key tax provisions that affected us, including a one-time re-measurements year-end In October 2016, the Financial Accounting Standards Board (“FASB”) issued accounting standards update 2016-16 2016-16, 2016-16 2016-16,	(13) Income Taxes There is no income tax provision for the years ended December 31, 2017, 2016 and 2015. Income (loss) before income taxes consists of: Year Ended December 31, (in thousands) 2017 2016 2015 Domestic $ (41,313 ) $ (13,930 ) $ (11,276 ) Foreign (3,804 ) (4,040 ) (3,428 ) Income (loss) before taxes $ (45,117 ) $ (17,970 ) $ (14,704 ) The provision for income taxes differs from the amount computed by applying the statutory rate as follows: Year Ended December 31, (in thousands) 2017 2016 2015 Income taxes using U.S federal statutory rate $ (15,340 ) $ (6,110 ) $ (4,999 ) Tax Cuts and Jobs Act 143 — — Nondeductible interest 6,912 — — Loss on extinguishment of debt 10,174 Loss of tax benefit of federal net operating loss carryforwards 5,067 68,795 — Loss of tax benefit of state net operating loss carryforwards 1,373 13,891 — Loss of tax benefit of federal tax credit carryforwards 324 4,023 — Amortization of gain on IP migration 767 767 767 State income taxes, net of federal benefit (1,339 ) (2,576 ) 380 Foreign rate differential 1,196 1,141 920 Valuation allowance (1,423 ) (75,407 ) 2,649 Derivative charge (8,403 ) (4,345 ) (192 ) Stock option exercises and cancellations 841 53 674 Research and development costs (295 ) (250 ) (199 ) Other 3 18 — $ — $ — $ — Significant components of the Company’s deferred tax assets are as follows: Year Ended December 31, (in thousands) 2017 2016 2015 Deferred tax assets: Employee compensation accruals $ 292 $ 1,386 $ 1,279 Accrued liabilities 353 343 633 Research tax credits 17 22 3,796 Other 34 55 66 Net operating losses 5,289 6,194 77,906 Total deferred tax assets 5,985 8,000 83,680 Deferred tax liabilities: Beneficial conversion feature — 906 — Other 13 — — Total deferred tax liabilities 13 906 — Valuation allowance 5,972 7,094 83,680 Net deferred tax assets $ — $ — $ — As of December 31, 2017, 2016 and 2015, the Company had net operating loss carryforwards for U.S. federal income tax purposes of approximately $211.3 million, $209.3 million and $184.5 million, respectively. A significant portion of the federal amount, $210.5 million, is subject to an annual limitation of approximately $27,500 as a result of a changes in the Company’s ownership in May 2003, November 2016 and multiple dates throughout 2017, as defined by Federal Internal Revenue Code Section 382 and the related income tax regulations. As a result of the limitations caused by the May 2003, November 2016 and multiple 2017 ownership changes, approximately $209.5 million of the total net operating loss carryforwards is expected to expire unutilized and will be unavailable to offset future federal taxable income. Approximately $1.0 million of net operating loss carryforwards remains available to offset future federal taxable income which will expire between 2018 and 2037. In addition, the Company’s state net operating losses are also subject to annual limitations that generally follow the federal Section 382 provisions (with the exception of Connecticut), adjusted for each state’s respective income apportionment percentages. As of December 31, 2017 and 2016, the Company had net operating loss carryforwards for state and city income tax purposes between approximately $27.3 million and $150.3 million and between approximately $27.3 million and $153.0 million, respectively, which expire through 2037. As a result of the 382 limitations, approximately $149.0 million and $133.3 million of New York State and New York City net operating losses are expected to expire unutilized and will be unavailable to offset future taxable income. Approximately $0.8 million and $0.8 million of net operating loss carryforwards, respectively, will be available to offset future state and city taxable income. As of December 31, 2017, 2016 and 2015, the Company had a net operating loss carryforward for foreign income tax purposes of $25.0 million, $21.1 million and $22.1 million, respectively, which have indefinite carryforward periods. As of December 31, 2017, 2016 and 2015, the Company had federal research and development tax credit carryforwards of approximately $4.3 million, $4.0 million and $3.8 million, respectively, which expire through 2037. As a result of the section 382 limitation, the entire tax credit carryforward is expected to expire unutilized. Management has established a 100% valuation allowance against the deferred tax assets as management does not believe it is more likely than not that these assets will be realized. The Company’s valuation allowance decreased by approximately $1.1 million and $76.6 million in 2017 and 2016, respectively. The primary reason for the significant decrease in the valuation allowance during 2016 is due to the reduction of recognizable deferred tax assets related net operating loss and credit carryforwards resulting from the Sec. 382 ownership change. The change in valuation allowance is as follows: (in thousands) December 31, December 31, Beginning balance $ 7,094 $ 83,680 Charged to costs and expenses (1,423 ) (75,407 ) Charged to additional paid-in capital — (1,854 ) Charged to retained earnings — 1,010 Charged to other comprehensive income 301 (335 ) Ending balance $ 5,972 $ 7,094 On December 22, 2017, the United States enacted the Tax Cuts and Jobs Act (the “Act”). The Act, which is also commonly referred to as “U.S. tax reform”, significantly changes U.S. corporate income tax laws by, among other provisions, reducing the maximum U.S. corporate income tax rate from 35% to 21% starting in 2018. At December 31, 2017, the Company has not completed its accounting for the tax effects of enactment of the Act; however, as described below, the Company has made a reasonable estimate of the effects on its existing deferred tax balances and the one-time transition During the year ended December 31, 2017, the Company reduced deferred tax assets by a provisional amount of $143,500, offset by a corresponding reduction to its valuation allowance, as a result of the re-measurement of The Act also requires a mandatory one-time inclusion The one-time transition the one-time transition On December, 22, 2017, SAB 118 was issued due to the complexities involved in accounting for the recently enacted Act. SAB 118 requires the Company to include in its financial statements a reasonable estimate of the impact of the Act on earnings to the extent such estimate has been determined. Accordingly, the U.S. provision for income tax for 2017 is based on the reasonable estimate guidance provided by SAB 118. The Company is continuing to assess the impact from the Act and will record adjustments in 2018 if necessary. The Company complies with the provisions of ASC 740-10 in ASC 740-10 addresses ASC 740-10, the ASC 740-10 and The Company is subject to income tax in the U.S., as well as various state and international jurisdictions. During the third quarter of 2015, the Internal Revenue Service commenced an examination of the Company’s federal income tax return for the year ended December 31, 2013. The examination was completed in the third quarter of 2017 and no changes were made to the reported amounts. Accordingly, there was no effect on the financial statements as a result of the examination. The Company has not been audited by any state tax authorities in connection with income taxes. The Company has not been audited by international tax authorities or any states in connection with income taxes. The Company’s New York State tax returns have been subject to annual desk reviews which have resulted in insignificant adjustments to the related franchise tax liabilities and credits. The Company is no longer subject to federal and state examination for tax years ending prior to December 31, 2014; tax years ending December 31, 2014 through December 31, 2017 remain open to examination. The Republic of Ireland is the Company’s only significant foreign jurisdiction. The Company is no longer subject to Ireland tax examination for tax years ending prior to December 31, 2013 (as Ireland has not initiated an audit of 2012 as of December 31, 2017); tax years ending December 31, 2013 through December 31, 2017 remain open to examination. However, the Company’s tax years December 31, 1998 through December 31, 2017 generally remain open to adjustment for all federal, state and foreign tax matters until its net operating loss and tax credit carryforwards are utilized or expire prior to utilization, and the applicable statutes of limitation have expired in the utilization year. 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. Delcath recognizes interest accrued related to unrecognized tax benefits and penalties, if incurred, as a component of income tax expense.

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	(14) Quarterly Financial Data (Unaudited) Set forth below is selected quarterly financial data for each of the quarters in the years ended December 31, 2017 and 2016. 2017 Quarters Ended (in thousands, except per share amounts) March 31 June 30 September 30 December 31 Revenue $ 743 $ 584 $ 684 $ 704 Costs and expenses 4,736 5,050 5,139 5,254 Operating loss (4,212 ) (4,601 ) (4,627 ) (4,725 ) Net loss (11,332 ) (1,943 ) (12,596 ) (19,246 ) Basic loss per share 43,750 1,750 4,680 375 2016 Quarters Ended (in thousands, except per share amounts) March 31 June 30 September 30 December 31 Revenue $ 370 $ 511 $ 435 $ 676 Costs and expenses 3,721 4,232 5,047 4,882 Operating loss (3,462 ) (3,871 ) (4,724 ) (4,383 ) Net loss (1,813 ) (6,667 ) (1,004 ) (8,486 ) Basic loss per share 218,750 771,750 115,495 646,010

Subsequent Events

Subsequent Events	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent Events	(12) Subsequent Events Additional Secured Convertible Note On July 20, 2018, the Company entered into a Securities Purchase Agreement with Discover Growth Fund, LLC for the remaining Notes and Warrants in proportionate amounts to those issued in the June 4, 2018 transaction which is discussed in Note 7, in a transaction exempt from registration pursuant to Section 4(a)(2) of the Securities Act and Rule 506(b) promulgated thereunder, and received gross proceeds of $1,600,000. Warrant Amendments On July 20, 2018, the Company and Discover Growth Fund amended the June 4, 2018 Securities Purchase Agreement to delay the Company’s registration obligation, and amended the Warrants issued thereunder so that they are exercisable as of the amendment date and the Company may redeem them at any time the Notes are no longer outstanding as well as to amend the Fundamental Transaction clause in each which result in the Series D Warrants no longer being treated as a liability as of the date of the amendment. Litigation On July 27, 2018, Hudson Bay Master Fund Ltd. filed a summons and complaint against the Company in the New York State Supreme Court, New York County (the “Suit”). The Suit alleges breaches by the Company of Hudson Bay’s rights of participation in future Company offerings granted in the September 2017 Securities Purchase Agreement between the Company and Hudson Bay and in the February 2018 Securities Purchase Agreement among, inter alia Rights Offering On August 3, 2018, our registration statement on Form S-1 basis, non-transferrable subscription	(15) Subsequent Events As of January 25, 2018, all of the Rights issued under the December 28, 2017 Exchange Agreements discussed in more detail in Note 9 to the Company’s consolidated financial statements contained in this Annual Report on Form 10-K have On February 9, 2018, the Company closed a registered offering of 212,000,000 shares of common stock, 38,000,000 pre-funded warrants to purchase 38,000,000 shares of common stock and Series D warrants to purchase an aggregate of 500,000,000 shares of common stock for total gross proceeds of approximately $5.0 million. The offering was priced at $0.02 per unit with each unit comprised of one share of common stock (or one pre-funded warrant) and one common stock purchase warrant to purchase two shares, provided that, with respect to the units with pre-funded warrants $0.019 per unit shall be paid at closing and $0.001 shall be paid upon exercise of each of the pre-funded warrants. The warrants carry a five-year term from the date of initial exercisability (which is later of one year from the date of issuance and date of amendment to articles of incorporation to increase number of authorized shares of common stock) with an exercise price of $0.02 per share. The securities were offered pursuant to a registration statement on Form S-1 (File No. 333-220898) On February 26, 2018, the Company filed a Definitive Proxy Statement on Schedule 14A seeking shareholder approval to increase its authorized shares of common stock from 500,000,000 to 1,000,000,000 in order to have sufficient authorized shares for full exercise of its recently issued Series D Warrants and for a reverse split of its common stock at a ratio of at least 1:100 but no more than 1:500, in the discretion of the Board of Directors and to grant authorization to the Board of Directors to determine, in its sole discretion, whether to implement the reverse stock split, as well as its specific timing (but not later than April 6, 2019). The Company increased its authorized shares of common stock to one billion and effected a reverse split of its issued and outstanding common stock in a ratio of one-for-five On May 2, 2018, the Company effected a reverse stock split at which time Delcath’s common stock began trading on the OTCQB on a one-for-five one-for-five

General

General	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	(1) General The unaudited interim condensed consolidated financial statements of Delcath Systems, Inc. (“Delcath” or the “Company”) as of and for the three and six months ended June 30, 2018 and 2017 should be read in conjunction with the consolidated financial statements included in the Company’s Annual Report on Form 10-K Description of Business Delcath Systems, Inc. is an interventional oncology company focused on the treatment of primary and metastatic liver cancers. Our investigational product—Melphalan Hydrochloride for Injection for use with the Delcath Hepatic Delivery System (Melphalan/HDS) —is designed to administer high-dose chemotherapy to the liver while controlling systemic exposure and associated side effects. In Europe, our system is commercially available under the trade name Delcath Hepatic CHEMOSAT ® ® Our primary research focus is on ocular melanoma liver metastases (mOM) and intrahepatic cholangiocarcinoma (ICC), a type of primary liver cancer, and certain other cancers that are metastatic to the liver. We believe the disease states we are investigating represent a multi-billion dollar global market opportunity and a clear unmet medical need. Our clinical development program for CHEMOSAT and Melphalan/HDS is comprised of The FOCUS Clinical Trial for Patients with Hepatic Dominant Ocular Melanoma (The FOCUS Trial), a Global Phase 3 clinical trial that is investigating overall survival in mOM, and The ALIGN Trial, a registration trial for intrahepatic cholangiocarcinoma (ICC). Our clinical development plan (CDP) also includes a commercial registry for CHEMOSAT non-clinical Liquidity and Operating Matters The accompanying financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The Company has incurred losses since inception and expects to continue incurring losses for the next several years. These losses, among other factors raises substantial doubt about the Company’s ability to continue as a going concern for a reasonable period of time. The Company’s existence is dependent upon management’s ability to obtain additional funding sources or to enter into strategic alliances. There can be no assurance that the Company’s efforts will result in the resolution of the Company’s liquidity needs. The accompanying statements do not include any adjustments that might result should the Company be unable to continue as a going concern. 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 S-X. The preparation of interim financial statements requires management to make assumptions and estimates that impact the amounts reported. These interim condensed consolidated financial statements, in the opinion of management, 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 June 30, 2018 and 2017; however, certain information and footnote disclosures normally 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. On May 2, 2018, the Company effected a reverse stock split at which time Delcath’s common stock began trading on the OTCQB on a one-for-five one-for-five 10-K Significant Accounting Policies A description of our significant accounting policies has been provided in Note 3 Summary of Significant Accounting Policies 10-K Recently Adopted Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update 2014-09, 2014-09”) 2014-09 On January 1, 2018, the Company adopted ASU 2014-09 Delcath generates revenue from the sales of its product in Europe, where its system is commercially available under the trade name Delcath Hepatic CHEMOSAT Delivery System for Melphalan (“CHEMOSAT ® Delcath has one distribution contract with a Turkish distributor. The contract has standard provisions for termination, renewal, limited warranty and right of return. CHEMOSAT kits are delivered to the Turkish distributor as orders are received and revenue is recognized at the time of shipment to the distributor. Delcath sells directly to centers in Europe with the exception of those centers located in Turkey. Sales are processed when purchase orders are received from the hospitals and revenue is recognized at the time of shipment to the treating center. In November 2016, the FASB issued ASU 2016-18, 2016-18 In June 2016, the FASB issued ASU 2016-15, Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, right-to-use 2016-02 In July 2017, the FASB issued ASU 2017-11, re-characterized re-characterization 2017-11

Net Loss per Common Share

Net Loss per Common Share	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Net Loss per Common Share	(10) Net Loss per Common 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. 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 and warrants are generally deemed anti-dilutive such that basic net loss per share and diluted net loss per share are equal. However, in certain periods in which the exercise price of the warrants was less than the last reported sales price of Delcath’s common stock on the final trading day of the period and there is a gain recorded pursuant to the change in fair value of the warrant derivative liability, the impact of gains related to the mark-to-market adjustment of the warrants outstanding at the end of the period is reversed and the treasury stock method is used to determine diluted earnings per share. June 30, (in thousands, except share data) 2018 2017 Net income (loss) - basic $ 527 $ (13,276 ) Adjustment for gain on warrant income (619 ) — Net loss - diluted $ (92 ) $ (13,276 ) Weighted average shares outstanding - basic 788,512 848 Weighted average shares outstanding - diluted 799,430 848 Net income (loss) per share - basic $ 0.67 $ (15,656 ) Net income (loss) per share - diluted $ (0.12 ) $ (15,656 ) The following potentially dilutive securities were excluded from the computation of earnings per share as of June 30, 2018 and June 30, 2017 because their effects would be anti-dilutive: June 30, June 30, 2018 2017 Stock options — 55,846 Unvested restricted shares — 101,294 Warrants 2,116,296 36,848 Assumed conversion of convertible notes 1,116,255 — Total 3,232,551 193,988

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Policies)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Liquidity and Operating Matters	Liquidity and Operating Matters The accompanying financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The Company has incurred losses since inception and expects to continue incurring losses for the next several years. These losses, among other factors raises substantial doubt about the Company’s ability to continue as a going concern for a reasonable period of time. The Company’s existence is dependent upon management’s ability to obtain additional funding sources or to enter into strategic alliances. There can be no assurance that the Company’s efforts will result in the resolution of the Company’s liquidity needs. The accompanying statements do not include any adjustments that might result should the Company be unable to continue as a going concern.	Liquidity The accompanying financial statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The Company has incurred losses since inception and has accumulated deficit of $324.8 million at December 31, 2017. As shown in the accompanying financial statements during the year ended December 31, 2017, the Company incurred net losses of $45.1 million and used $15.4 million of cash for its operating activities. These factors among others raise substantial doubt about the Company’s ability to continue as a going concern for a reasonable period of time. The Company’s existence is dependent upon management’s ability to obtain additional funding sources or to enter into strategic alliances. Adequate additional financing may not be available to us on acceptable terms, or at all. If the Company is unable to raise additional capital and/or enter into strategic alliances when needed or on attractive terms, it would be forced to delay, reduce or eliminate our research and development programs or any commercialization efforts. There can be no assurance that the Company’s efforts will result in the resolution of the Company’s liquidity needs. If Delcath is not able to continue as a going concern, it is likely that holders of its common stock will lose all of their investment. The accompanying consolidated financial statements do not include any adjustments that might result should the Company be unable to continue as a going concern. The Company anticipates incurring additional losses until such time, if ever, that it can generate significant sales. Management believes that its capital resources are adequate to fund operations through May 2018. Additional working capital will be required to continue operations. Operations of the Company are subject to certain risks and uncertainties, including, among others, uncertainty of product development and clinical trial results; uncertainty regarding regulatory approval; technological uncertainty; uncertainty regarding patents and proprietary rights; comprehensive government regulations; limited commercial manufacturing, marketing or sales experience; and dependence on key personnel.
Use of Estimates		Use of Estimates The Company bases its estimates and judgments on historical experience and on various other assumptions that it believes are reasonable under the circumstances. The amounts of assets and liabilities reported in the Company’s consolidated balance sheets and the amount of revenues and expenses reported for each of the periods presented are affected by estimates and assumptions, which are used for, but not limited to, the accounting for derivative instrument liabilities, stock-based compensation, valuation of inventory, impairment of long-lived assets, income taxes and operating expense accruals. Such assumptions and estimates are subject to change in the future as additional information becomes available or as circumstances are modified. Actual results could differ from these estimates.
Cash Equivalents and Concentrations of Credit Risk		Cash Equivalents and Concentrations of Credit Risk The Company considers investments with original maturities of three months or less at date of acquisition to be cash equivalents. The Company has deposits that exceed amounts insured by the Federal Deposit Insurance Corporation (FDIC), however, the Company does not consider this a significant concentration of credit risk based on the strength of the financial institution.
Restricted Cash		Restricted Cash Cash and cash equivalents that are restricted as to withdrawal or use under the terms of certain contractual agreements are recorded as restricted cash on the accompanying consolidated balance sheets.
Accounts Receivable		Accounts Receivable Accounts receivable, principally trade, are generally due within 30 days and are stated at amounts due from customers. Collections and payments from customers are monitored and a provision for estimated credit losses may be created based upon historical experience and specific customer collection issues that may be identified.
Inventories		Inventories Inventories are valued at the lower of cost or market value using the first-in, first-out method. The products, work-in-process, and Prior to obtaining authorization to affix the CE Mark to its Generation Two CHEMOSAT System in April 2012, the Company expensed all of its inventory costs as research and development. Inventory as of December 31, 2017 includes finished goods and components that have been purchased since April 2012. Therefore, to the extent that materials expensed prior to April 2012 are used in manufacturing finished goods for sale, the Company’s cost of goods sold will be impacted accordingly.
Property, Plant and Equipment		Property, Plant and Equipment Property, plant and equipment are recorded at cost, less accumulated depreciation. The Company provides for depreciation on a straight line basis over the estimated useful lives of the assets which range from three to seven years. Leasehold improvements will be amortized over the shorter of the lease term or the estimated useful life of the related assets when they are placed into service. The Company evaluates property, plant and equipment for impairment periodically to determine if changes in circumstances or the occurrence of events suggest the carrying value of the asset or asset group may not be recoverable. Maintenance and repairs are charged to operations as incurred. Expenditures which substantially increase the useful lives of the related assets are capitalized.
Derivative Instrument Liability		Derivative Instrument Liability The Company accounts for derivative instruments in accordance with Accounting Standards Codification (ASC) 815, which establishes accounting and reporting standards for derivative instruments and hedging activities, including certain derivative instruments embedded in other financial instruments or contracts and requires recognition of all derivatives on the balance sheet at fair value, regardless of the hedging relationship designation. Accounting for changes in the fair value of the derivative instruments depends on whether the derivatives qualify as hedge relationships and the types of relationships designated are based on the exposures hedged. At December 31, 2017 and 2016, the Company did not have any derivative instruments that were designated as hedges.
Fair Value Measurements		Fair Value Measurements The Company adheres to ASC 820, which defines fair value, establishes a framework for measuring fair value, and expands disclosures about fair value measurements. ASC 820 applies to reported balances that are required or permitted to be measured at fair value under existing accounting pronouncements; accordingly, the standard does not require any new fair value measurements of reported balances. ASC 820 emphasizes that fair value is a market-based measurement, not an entity-specific measurement. Therefore, a fair value measurement should be determined based on the assumptions that market participants would use in pricing the asset or liability. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a fair value hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity (observable inputs that are classified within Levels 1 and 2 of the hierarchy) and the reporting entity’s own assumptions about market participant assumptions (unobservable inputs classified within Level 3 of the hierarchy). • Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access. • Level 2 inputs are inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Level 2 inputs may include quoted prices for similar assets and liabilities in active markets, as well as inputs that are observable for the asset or liability (other than quoted prices), such as interest rates, foreign exchange rates, and yield curves that are observable at commonly quoted intervals. • Level 3 inputs are unobservable inputs for the asset or liability, which is typically based on an entity’s own assumptions, as there is little, if any, related market activity. In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability.
Revenue Recognition		Revenue Recognition Revenue from product sales is generally recognized when all of the following criteria have been met: persuasive evidence of an arrangement exists; delivery has occurred; product price is fixed or determinable; and collection of the resulting receivable is reasonably assured. When obligations or contingencies remain after the products are shipped, such as training and certifying the treatment centers, revenue is deferred until the obligations or contingencies are satisfied.
Deferred Revenue		Deferred Revenue Deferred revenue on the accompanying consolidated balance sheets includes payment received for product sales to a distributor. When obligations or contingencies remain after the products are shipped, such as training and certifying the treatment centers, revenue is deferred until the obligations or contingencies are satisfied. The Company will recognize the revenue related to product sales when its obligations under the agreement have been satisfied.
Selling, General and Administrative		Selling, General and Administrative Selling, general and administrative costs include personnel costs and related expenses for the Company’s sales, marketing, general management and administrative staff, recruitment, costs related to the Company’s commercialization efforts in Europe, professional service fees, professional license fees, business development and certain general legal activities. All such costs are charged to expense when incurred.
Research and Development		Research and Development Research and development costs include the costs of materials used for clinical trials and R&D, personnel costs associated with device and pharmaceutical R&D, clinical affairs, medical affairs, medical science liaisons, and regulatory affairs, costs of outside services and applicable indirect costs incurred in the development of the Company’s proprietary drug delivery system. All such costs are charged to expense when incurred.
Stock Based Compensation		Stock Based Compensation The Company accounts for its share-based compensation in accordance with the provisions of ASC 718, which establishes accounting for equity instruments exchanged for employee services and ASC 505-50, which to non-employees. Under ASC 505-50, measurement to non-employees for of non-employee stock-based The Company periodically grants stock options for a fixed number of shares of common stock to its employees, directors and non-employee
Income Taxes		Income Taxes The Company accounts for income taxes following the asset and liability method in accordance with the ASC 740 “Income Taxes.” Under such method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax bases. The Company applies the accounting guidance issued to address the accounting for uncertain tax positions. This guidance clarifies the accounting for income taxes, by prescribing a minimum recognition threshold a tax position is required to meet before being recognized in the financial statements as well as provides guidance on derecognition, measurement, classification, interest and penalties, accounting in interim periods, disclosure and transition. The Company classifies interest and penalty expense related to uncertain tax positions as a component of income tax expense. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years that the asset is expected to be recovered or the liability settled. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The ultimate realization of deferred tax assets depends on the generation of future taxable income during the period in which related temporary differences become deductible. The Company considers the scheduled reversal of deferred tax liabilities, projected future taxable income and tax planning strategies in its assessment of a valuation allowance. See Note 13 for additional information.
Net Loss per Common Share		Net Loss per Common Share Basic net loss per share is determined by dividing net loss by the weighted average shares of common stock outstanding during the period. 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 stock options, unvested restricted stock and warrants are deemed anti-dilutive such that basic net loss per share and diluted net loss per share are equal. The calculation of net loss and the number of shares used to compute basic and diluted earnings per share for the years ended December 31, 2017, 2016 and 2015 are as follows: (in thousands, except share data) 2017 2016 2015 Net loss $ (45,117 ) $ (17,971 ) $ (14,704 ) Preferred stock dividends (527 ) — — Net loss, adjusted (45,644 ) (17,971 ) (14,704 ) Net loss per share – basic and diluted (3,250 ) (1,853,500 ) (2,548,000 ) Weighted average shares outstanding – basic and diluted 14,039 10 6 In the third quarter of 2017, the Company issued Series B Preferred Shares. A portion of the redemption price of the Series B Preferred Shares was accounted for as a deemed dividend and is discussed further in Note 10. For the years ended December 31, 2017, 2016 and 2015, the following potentially dilutive securities were excluded from the computation of diluted earnings per share (EPS) because their effects would be antidilutive. Shares excluded from the computation of diluted EPS: 2017 2016 2015 Stock options — — — Unvested restricted shares — — — Warrants 14,049 41 65 Total 14,049 41 63
Segment Information		Segment Information The Company currently operates in one business segment, which is the development and commercialization of CHEMOSAT/Melphalan/HDS. A single management team that reports to the CEO and President comprehensively manages the business. Accordingly, the Company does not have separately reportable segments.
Foreign Currency and Currency Translation		Foreign Currency and Currency Translation Transactions that are denominated in a foreign currency are remeasured into the functional currency at the current exchange rate on the date of the transaction. Any foreign currency-denominated monetary assets and liabilities are subsequently remeasured at current exchange rates, with gains or losses recognized as foreign exchange (losses)/gains in the statements of operations. The assets and liabilities of the Company’s international subsidiaries are translated from their functional currencies into United States dollars at exchange rates prevailing at the balance sheet date. Average rates of exchange during the period are used to translate the statement of operations, while historical rates of exchange are used to translate any equity transactions. Translation adjustments arising on consolidation due to differences between average rates and balance sheet rates, as well as unrealized foreign exchange gains or losses arising from translation of intercompany loans that are of a long-term-investment nature, are recorded in other comprehensive income.
Recent Accounting Pronouncements	Recently Adopted Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update 2014-09, 2014-09”) 2014-09 On January 1, 2018, the Company adopted ASU 2014-09 Delcath generates revenue from the sales of its product in Europe, where its system is commercially available under the trade name Delcath Hepatic CHEMOSAT Delivery System for Melphalan (“CHEMOSAT ® Delcath has one distribution contract with a Turkish distributor. The contract has standard provisions for termination, renewal, limited warranty and right of return. CHEMOSAT kits are delivered to the Turkish distributor as orders are received and revenue is recognized at the time of shipment to the distributor. Delcath sells directly to centers in Europe with the exception of those centers located in Turkey. Sales are processed when purchase orders are received from the hospitals and revenue is recognized at the time of shipment to the treating center. In November 2016, the FASB issued ASU 2016-18, 2016-18 In June 2016, the FASB issued ASU 2016-15, Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, right-to-use 2016-02 In July 2017, the FASB issued ASU 2017-11, re-characterized re-characterization 2017-11	Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, Revenue (“ASU 2014-09”) that ASU 2014-09 also ASU 2014-09 is ASU 2014-09 compared ASU 2014-09 to In February 2016, the FASB issued ASU No. 2016-02, Leases, a right-to-use asset ASU 2016-02 is In June 2016, the FASB issued ASU 2016-15, Statement In November 2016, the FASB issued ASU 2016-18, Statement ASU 2016-18 is In July 2017, the FASB issued ASU 2017-11, Earnings Board re-characterized the The re-characterization has ASU 2017-11 is
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 S-X. The preparation of interim financial statements requires management to make assumptions and estimates that impact the amounts reported. These interim condensed consolidated financial statements, in the opinion of management, 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 June 30, 2018 and 2017; however, certain information and footnote disclosures normally 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. On May 2, 2018, the Company effected a reverse stock split at which time Delcath’s common stock began trading on the OTCQB on a one-for-five one-for-five 10-K

Net Loss per Common Share (Tabl

Net Loss per Common Share (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Calculation of net loss and number of shares used to compute basic and diluted earnings 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. 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 and warrants are generally deemed anti-dilutive such that basic net loss per share and diluted net loss per share are equal. However, in certain periods in which the exercise price of the warrants was less than the last reported sales price of Delcath’s common stock on the final trading day of the period and there is a gain recorded pursuant to the change in fair value of the warrant derivative liability, the impact of gains related to the mark-to-market adjustment of the warrants outstanding at the end of the period is reversed and the treasury stock method is used to determine diluted earnings per share. June 30, (in thousands, except share data) 2018 2017 Net income (loss) - basic $ 527 $ (13,276 ) Adjustment for gain on warrant income (619 ) — Net loss - diluted $ (92 ) $ (13,276 ) Weighted average shares outstanding - basic 788,512 848 Weighted average shares outstanding - diluted 799,430 848 Net income (loss) per share - basic $ 0.67 $ (15,656 ) Net income (loss) per share - diluted $ (0.12 ) $ (15,656 )	The calculation of net loss and the number of shares used to compute basic and diluted earnings per share for the years ended December 31, 2017, 2016 and 2015 are as follows: (in thousands, except share data) 2017 2016 2015 Net loss $ (45,117 ) $ (17,971 ) $ (14,704 ) Preferred stock dividends (527 ) — — Net loss, adjusted (45,644 ) (17,971 ) (14,704 ) Net loss per share – basic and diluted (3,250 ) (1,853,500 ) (2,548,000 ) Weighted average shares outstanding – basic and diluted 14,039 10 6
Anti-dilutive 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 June 30, 2018 and June 30, 2017 because their effects would be anti-dilutive: June 30, June 30, 2018 2017 Stock options — 55,846 Unvested restricted shares — 101,294 Warrants 2,116,296 36,848 Assumed conversion of convertible notes 1,116,255 — Total 3,232,551 193,988	Shares excluded from the computation of diluted EPS: 2017 2016 2015 Stock options — — — Unvested restricted shares — — — Warrants 14,049 41 65 Total 14,049 41 63

Inventories (Tables)

Inventories (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Schedule of inventories	Inventories consist of the following: (in thousands) June 30, 2018 December 31, 2017 Raw materials $ 339 $ 298 Work-in-process 755 721 Finished goods 156 229 Total inventories $ 1,250 $ 1,248	Inventories consist of: (in thousands) December 31, December 31, Raw materials $ 298 $ 346 Work-in-process 721 214 Finished goods 229 100 Total Inventory $ 1,248 $ 660

Prepaid Expenses and Other Cu29

Prepaid Expenses and Other Current Assets (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following: (in thousands) June 30, 2018 December 31, 2017 Insurance premiums $ 168 $ 421 Security deposit 50 50 VAT/GST receivable 37 29 Software 26 15 Financing costs 25 70 Other 1 76 115 Total prepaid expenses and other current assets $ 382 $ 700 1 Other consists of various prepaid expenses and other current assets, with no individual item accounting for more than 5% of prepaid expenses and other current assets at June 30, 2018 and December 31, 2017.	Prepaid expenses and other current assets include the following: (in thousands) December 31, December 31, Insurance premiums $ 421 $ 501 Financing costs 70 — Security deposit 50 50 Other 1 159 147 Total prepaid expenses and other current assets $ 700 $ 698 1 Other consists of various prepaid expenses and other current assets, with no individual item accounting for more than 5% at December 31, 2017 and 2016.

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Components of property, plant and equipment	Property, plant, and equipment consist of the following: (in thousands) June 30, 2018 December 31, 2017 Buildings and land $ 579 $ 579 Enterprise hardware and software 1,743 1,744 Leaseholds 1,702 1,705 Equipment 979 971 Furniture 199 175 Property, plant and equipment, gross 5,202 5,174 Accumulated depreciation (4,103 ) (3,876 ) Property, plant and equipment, net $ 1,099 $ 1,298	Property, plant, and equipment consists of: (in thousands) December 31, December 31, Buildings and land $ 579 $ 556 Enterprise hardware and software 1,744 1,532 Leaseholds 1,705 1,504 Equipment 971 940 Furniture 175 354 Property, plant and equipment, gross 5,174 4,886 Accumulated depreciation (3,876 ) (3,803 ) Property, plant and equipment, net $ 1,298 $ 1,083

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Schedule of accrued expenses	Accrued expenses consist of the following: (in thousands) June 30, 2018 December 31, 2017 Compensation, excluding taxes $ 1,573 $ 869 Clinical trial expenses 2,304 1,124 Professional fees 314 221 Short-term portion of lease restructuring 193 209 Other 1 836 985 Total accrued expenses $ 5,220 $ 3,408 1 Other consists of various accrued expenses, with no individual item accounting for more than 5% of current liabilities at June 30, 2018 and December 31, 2017.	Current accrued expenses include the following: (in thousands) December 31, December 31, Clinical trial expenses $ 869 $ 1,365 Compensation, excluding taxes 1,124 933 Professional fees 221 286 Short-term portion of lease restructuring 209 216 Other 1 985 607 Total accrued expenses $ 3,408 $ 3,407 1 Other consists of various accrued expenses, with no individual item accounting for more than 5% of current liabilities at December 31, 2017 and 2016.

Restructuring Expenses (Tables)

Restructuring Expenses (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Schedule of restructuring and related costs	The following table provides the year-to-date (in thousands) Lease Liability Reserve balance at December 31, 2017 $ 604 Charges — Payments/Utilizations (109 ) Reserve balance at June 30, 2018 $ 495	The following table provides the year-to-date activity (in thousands) Lease Liability Reserve balance at December 31, 2016 $ 820 Charges — Payments/Utilizations (216 ) Reserve balance at December 31, 2017 $ 604

Secured Convertible Notes Pay33

Secured Convertible Notes Payable and Common Stock Purchase Warrants (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Debt Disclosure Abstract
Summary of Common Stock and Preferred Stock Shares Issued under Notes and New Notes		The Company has issued shares of Common Stock and Preferred Stock as payments of principal (including certain early repayments at the option of the holders) and effected a retirement under the Notes and New Notes as follows: Number of Number of Applicable Reduction in January 12, 2017 23 — $ 63,000.00 $ 1,478,318 January 26 - February 1, 2017 1 10 — $ 56,000.00 $ 544,000 February 10, 2017 87 — $ 35,000.00 $ 3,045,817 February 23 - March 2, 2017 1 5 — $ 24,500.00 $ 125,999 March 13, 2017 229 — $ 19,250.00 $ 4,417,829 April 10, 2017 344 — $ 10,500.00 $ 3,621,286 May 9, 2017 218 — $ 8,750.00 $ 1,913,915 June 7 / July 2, 2017 Exchange Agreement 2 1,380 4,200 $ 12,250.00 $ 4,200,000 July 7, 2017 229 — $ 12,250.00 $ 2,000,000 August 4, 2017 83 — $ 5,250.00 $ 1,015,848 August 28, 2017 Restructuring Agreement 3 229 — $ 5,250.00 $ 1,200,000 November 6, 2017 Warrant Exchange 4 — — $ — $ 279,016 November 15, 2017 Exchange Agreements 5 194,896 — $ 41.72 $ 8,130,564 Retirement per December 28, 2017 Exchange Agreements 6 — — $ — $ 553,234 December 28, 2017 Exchange Agreements 6 445,152 — $ 10.00 $ 2,474,174 Total 642,885 $ 35,000,000 1 During the periods referenced above, the Company and the holders of the Notes agreed to a temporary reduction in the conversion price in order to encourage voluntary conversion of Notes by the holders thereof. 2 On July 2, 2017, the Company entered into an exchange agreement with one of its investors which had purchased Notes, for $4.2 million aggregate principal amount of such Notes for 4,200 shares of Series A Preferred Stock. The Series A Preferred Stock shares were issued to address a short-term valuation issue for 1,380 common shares delivered to the Notes holders to close an installment period. Through the Series A Preferred Shares placement, the Company was able to value the open installment shares such that the amount of debt remaining under the Notes was reduced by $4.2 million. Additionally, the Company recognized a loss on debt settlement of $1.0 million related to this transaction. 3 On August 28, 2017, the Company entered into a restructuring agreement with one of its investors which had purchased Notes. The restructuring agreement included a provision to exchange 229 shares for $1.2 million aggregate principal amount of such Notes. Additionally, the Company recognized a loss on debt settlement of $1.9 million related to this transaction. 4 On October 10, 2017, the Company entered into an amendment to the August 28, 2017 Restructuring Agreement which included a provision to exchange debt for the issuance of warrants. Additionally, the Company recognized a loss on debt extinguishment of $2.3 million. 5 On November 15, 2017, the Company entered into an exchange agreement which included a provision to exchange 1,948 shares for $0.6 million aggregate principal amount of such Notes. Additionally, the Company issued 192,948 million shares for $7.5 million aggregate principal amount of Notes under the updated conversion price formula as discussed in more detail above. Additionally, the Company recognized a loss on debt extinguishment of $21.0 million in connection with the issuance of the New Notes and warrants as part of such exchange. 6 On December 28, 2017, the Company entered into an exchange agreement to retire $0.6 million aggregate principal amount of Notes and to issue 247,417 million shares and rights for shares for the remaining $2.5 million aggregate principal amount of Notes. Additionally, the Company recognized a loss on debt extinguishment of $3.7 million.
Schedule of Inputs Used to Value the Series D Warrants	The Company valued the Series D Warrants using the following inputs: Warrant D-1 Warrant D-2 Expected life (in years) 5.0 5.5 - 6.5 Expected volatility 194.10% 215.0% - 389.0% Risk-free interest rates 2.78% 2.13% - 2.30%

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Stockholders Equity Note Abstract
Stock option activity	Stock option activity for 2017, 2016 and 2015 is as follows: Stock Option Activity under the Plans (1) Stock Exercise Price per Weighted Average Weighted Average Outstanding at December 31, 2014 0 $ 0 - $0 $ 0 0 Granted 0 0 0 0 Forfeited (0 ) 0-0 0 0 Outstanding at December 31, 2015 0 $ 0 - $0 $ 0 0 Granted — — — Forfeited (0 ) 0-0 0 0 Outstanding at December 31, 2016 0 $ 0 - $0 $ 0 0 Granted 0 $ 0 $ 0 0 Forfeited (0 ) $ 0 $ 0 0 Outstanding at December 31, 2017 0 $ 0 - $0 $ 0 0 Exercisable at December 31, 2017 0 $ 0 - $0 $ 0 0 (1) Due to the May 2, 2018 1-for-500 reverse stock split, and no fractional shares being issued, all numbers are reduced to zero.
Assumptions used to determine estimated fair value of stock options granted	The estimated fair value of each option award granted was determined on the date of grant using an option pricing model with the following assumptions for option grants made in 2017 and 2015. There were no option grants during 2016. Year ended Year ended 2017 2015 Weighted average risk-free interest rates 2.15 % 1.82 % Weighted average expected volatility 170.42 % 97.70 % Dividend yield — — Weighted average expected option term (in years) 7.29 5.15 Weighted average grant date fair value $ 82.34 $ 4,964.73
Summary of restricted stock activity	A summary of the Company’s non-vested options Non-Vested Options (1) Number of Weighted Non-vested at 0 $ 0 Granted — — Vested (0 ) 0 Forfeited (0 ) 0 Non-vested at 0 $ 0 Granted 0 0 Vested (0 ) 0 Forfeited (0 ) 0 Non-vested at 0 $ 0
Summary of non-vested options	A summary of the Company’s restricted stock activity as of December 31, 2017 and changes during the years ended December 31, 2017 and December 31, 2016 are presented below: Restricted Stock Activity (1) Number of Weighted Non-vested at — $ — Granted — — Vested — — Forfeited — — Non-vested at — $ — Granted — — Vested — — Forfeited — — Non-vested at — $ — (1) Due to the May 2, 2018 1-for-500 reverse stock split, and no fractional shares being issued, all numbers are reduced to zero.
Summary of warrant activity	The Company issued warrants as part of its offerings in 2013, 2015, and 2016 as well as part of its issuance of convertible notes in 2016 and an exchange agreement in 2017. A summary of warrant activity is as follows: Warrants Exercise Price Weighted Weighted Outstanding at January 1, 2014 9 $ 4,900,000-$19,712,000 $ 15,170,879 2.78 Issued 35 2,240,000 Exercised (- ) 2,296,000 Expired (- ) 2,296,000 Outstanding at December 31, 2015 44 $ 2,072,000-19,712,000 $ 44,858,633 2.16 Issued 30 840,000 Exercised (3 ) 481,250 Expired (3 ) 994,000 Outstanding at December 31, 2016 78 $ 281,750-$19,712,000 $ 910,000 5.59 Issued 14,256 2,299 Exercised (246 ) 4,221 Expired (39 ) 845,250 Outstanding at December 31, 2017 14,049 $ 1,225-19,712,000 $ 1,569 4.88

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Schedule of fair value of the warrants	The fair value of the Warrants at June 30, 2018 and December 31, 2017 was determined by using option pricing models with the following assumptions: June 30, 2018 December 31, 2017 Expected life (in years) 0.33 - 6.40 0.82 - 4.88 Expected volatility 132.69% - 372.0% 130.88% - 266.92% Risk-free interest rates 1.99% -2.92% 1.68% - 2.06%	The fair value of the Warrants at December 31, 2017 was determined by using option pricing models assuming the following: November October 2016 July 2015 February October 2013 Expected volatility 217.39 % 130.88 % 161.87 % 169.95 % 266.92 % Risk free interest rates 1.98 % 2.06 % 1.94 % 1.90 % 1.68 % Expected life (in years) 4.88 3.76 2.56 2.13 0.82
Assets and liabilities measured at fair value on a recurring basis	The table below presents the Company’s assets and liabilities measured at fair value on a recurring basis as of June 30, 2018, aggregated by the level in the fair value hierarchy within which those measurements fall in accordance with ASC 820. Assets and Liabilities Measured at Fair Value on (in thousands) Level 1 Level 2 Level 3 Balance at June 30, 2018 Liabilities Derivative instrument liabilities $ — $ — $ 6,883 $ 6,883	The table below presents the Company’s assets and liabilities measured at fair value on a recurring basis as of December 31, 2017 and 2016, aggregated by the level in the fair value hierarchy within which those measurements fall. Assets and Liabilities Measured at Fair Value on a Recurring Basis Assets and Liabilities Measured at Fair Value on a Recurring Basis Level 1 Level 2 Level 3 Balance at (in thousands) 2017 2016 2017 2016 2017 2016 2017 2016 Liabilities Derivative instrument liabilities $ — $ — $ — $ — $ 560 $ 18,751 $ 560 $ 18,751
Fair value measurements using significant unobservable inputs	The table below presents the activity within Level 3 of the fair value hierarchy for the six months ended June 30, 2018: Fair Value Measurements Using Significant Unobservable Inputs (Level 3) (in thousands) Warrant Balance at December 31, 2017 $ 560 Fair value of warrants issued 23,532 Fair value of warrants exercised — Total change in the liability included in earnings (17,209 ) Balance at June 30, 2018 $ 6,883	Fair Value Measurements Using Significant Unobservable Inputs (Level 3) (in thousands) Warrant Liability Balance at January 1, 2015 $ 225 Total change in the liability included in earnings (564 ) Fair value of warrants issued 4,247 Fair value of warrants exercised (123 ) Balance at December 31, 2015 3,785 Total change in the liability included in earnings (12,780 ) Fair value of warrants issued 28,472 Fair value of warrants exercised (726 ) Balance at December 31, 2016 $ 18,751 Total change in the liability included in earnings (15,103 ) Extinguishment of convertible note warrant (17,489 ) Fair value of warrants issued 16,953 Fair value of warrants exercised (2,552 ) Balance at December 31, 2017 $ 560

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of future minimum lease payments, net of receipts due under terms of subleases under all operating leases	Future minimum lease payments, net of receipts due under the terms of subleases, under all operating leases at December 31, 2017 are as follows: (in thousands) Future Lease 2018 872 2019 501 2020 456 2021 281 2022 — 2023 — $ 2,110

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Income (Loss) Before Income Taxes	Income (loss) before income taxes consists of: Year Ended December 31, (in thousands) 2017 2016 2015 Domestic $ (41,313 ) $ (13,930 ) $ (11,276 ) Foreign (3,804 ) (4,040 ) (3,428 ) Income (loss) before taxes $ (45,117 ) $ (17,970 ) $ (14,704 )
Income tax reconciliation	The provision for income taxes differs from the amount computed by applying the statutory rate as follows: Year Ended December 31, (in thousands) 2017 2016 2015 Income taxes using U.S federal statutory rate $ (15,340 ) $ (6,110 ) $ (4,999 ) Tax Cuts and Jobs Act 143 — — Nondeductible interest 6,912 — — Loss on extinguishment of debt 10,174 Loss of tax benefit of federal net operating loss carryforwards 5,067 68,795 — Loss of tax benefit of state net operating loss carryforwards 1,373 13,891 — Loss of tax benefit of federal tax credit carryforwards 324 4,023 — Amortization of gain on IP migration 767 767 767 State income taxes, net of federal benefit (1,339 ) (2,576 ) 380 Foreign rate differential 1,196 1,141 920 Valuation allowance (1,423 ) (75,407 ) 2,649 Derivative charge (8,403 ) (4,345 ) (192 ) Stock option exercises and cancellations 841 53 674 Research and development costs (295 ) (250 ) (199 ) Other 3 18 — $ — $ — $ —
Significant components of deferred tax assets	Significant components of the Company’s deferred tax assets are as follows: Year Ended December 31, (in thousands) 2017 2016 2015 Deferred tax assets: Employee compensation accruals $ 292 $ 1,386 $ 1,279 Accrued liabilities 353 343 633 Research tax credits 17 22 3,796 Other 34 55 66 Net operating losses 5,289 6,194 77,906 Total deferred tax assets 5,985 8,000 83,680 Deferred tax liabilities: Beneficial conversion feature — 906 — Other 13 — — Total deferred tax liabilities 13 906 — Valuation allowance 5,972 7,094 83,680 Net deferred tax assets $ — $ — $ —
Summary of Change in Valuation Allowance	The primary reason for the significant decrease in the valuation allowance during 2016 is due to the reduction of recognizable deferred tax assets related net operating loss and credit carryforwards resulting from the Sec. 382 ownership change. The change in valuation allowance is as follows: (in thousands) December 31, December 31, Beginning balance $ 7,094 $ 83,680 Charged to costs and expenses (1,423 ) (75,407 ) Charged to additional paid-in capital — (1,854 ) Charged to retained earnings — 1,010 Charged to other comprehensive income 301 (335 ) Ending balance $ 5,972 $ 7,094

Quarterly Financial Data (Una38

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Selected quarterly financial data	Set forth below is selected quarterly financial data for each of the quarters in the years ended December 31, 2017 and 2016. 2017 Quarters Ended (in thousands, except per share amounts) March 31 June 30 September 30 December 31 Revenue $ 743 $ 584 $ 684 $ 704 Costs and expenses 4,736 5,050 5,139 5,254 Operating loss (4,212 ) (4,601 ) (4,627 ) (4,725 ) Net loss (11,332 ) (1,943 ) (12,596 ) (19,246 ) Basic loss per share 43,750 1,750 4,680 375 2016 Quarters Ended (in thousands, except per share amounts) March 31 June 30 September 30 December 31 Revenue $ 370 $ 511 $ 435 $ 676 Costs and expenses 3,721 4,232 5,047 4,882 Operating loss (3,462 ) (3,871 ) (4,724 ) (4,383 ) Net loss (1,813 ) (6,667 ) (1,004 ) (8,486 ) Basic loss per share 218,750 771,750 115,495 646,010

General - Additional Informatio

General - Additional Information (Detail) $ / shares in Units, $ in Thousands	May 02, 2018$ / sharesshares	Nov. 06, 2017$ / sharesshares	Jul. 21, 2016$ / sharesshares	Jun. 30, 2018USD ($)$ / shares	Dec. 31, 2017USD ($)$ / shares	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)$ / shares	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Jun. 30, 2018USD ($)Contract$ / shares	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)$ / shares	Dec. 31, 2016USD ($)$ / shares	Dec. 31, 2015USD ($)
Class Of Stock [Line Items]
Net loss				$ 6,658	$ 19,246	$ 12,596	$ 1,943	$ 11,332	$ 8,486	$ 1,004	$ 6,667	$ 1,813	$ (527)	$ 13,276	$ 45,117	$ 17,971	$ 14,704
Net cash used in operating activities															15,398
Accumulated deficit				$ 324,305	$ 324,832				$ 279,188				$ 324,305		$ 324,832	$ 279,188
Reverse stock split	1:500	1:350
Reverse stock split ratio	0.0020	0.0029	0.0625
Number of fractional shares were issued in connected with the reverse stock split | shares			0
Common stock, par value (in dollars per share) | $ / shares			$ 0.01	$ 0.01	$ 0.01				$ 0.01				$ 0.01		$ 0.01	$ 0.01
Number of distribution contracts with Turkish distributor | Contract													1
OTCQB [Member]
Class Of Stock [Line Items]
Reverse stock split	1:500
Reverse stock split ratio	0.0020	0.0029
Number of fractional shares were issued in connected with the reverse stock split | shares	0	0
Common stock, par value (in dollars per share) | $ / shares	$ 0.01	$ 0.01

Summary of Significant Accoun40

Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017Segment
Summary Of Significant Accounting Policies [Line Items]
Maximum period of investments with original maturities from date of acquisition to be cash equivalents	3 months
Number of business segments	1
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	3 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives	7 years

Net Loss per Common Share - Cal

Net Loss per Common Share - Calculation of Net Loss and Number of Shares Used to Compute Basic and Diluted Earnings per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended											6 Months Ended				12 Months Ended
		Jun. 30, 2018		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017		Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2018		Jun. 30, 2017		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net loss		$ (6,658)		$ (19,246)	$ (12,596)	$ (1,943)		$ (11,332)	$ (8,486)	$ (1,004)	$ (6,667)	$ (1,813)	$ 527		$ (13,276)		$ (45,117)	$ (17,971)	$ (14,704)
Preferred stock dividends																	(527)
Net income (loss) - basic													527		(13,276)		$ (45,644)	$ (17,971)	$ (14,704)
Adjustment for gain on warrant income													(619)
Net loss per share - basic and diluted	[1]																$ (3,250)	$ (1,853,500)	$ (2,548,000)
Net loss - diluted													$ (92)		$ (13,276)
Weighted average shares outstanding - basic and diluted	[1]																14,039	10	6
Weighted average shares outstanding - basic	[2]	916,706				1,416							788,512		848
Weighted average shares outstanding - diluted	[2]	916,706				1,416							799,430		848
Net income (loss) per share - basic		$ (7.26)	[2]	$ 375	$ 4,680	$ (1,373)	[2]	$ 43,750	$ 646,010	$ 115,495	$ 771,750	$ 218,750	$ 0.67	[2]	$ (15,656)	[2]
Net income (loss) per share - diluted	[2]	$ (7.26)				$ (1,373)							$ (0.12)		$ (15,656)
[1]	reflects a one-for-sixteen (1:16) reverse stock split effected on July 21, 2016, a one-for-three hundred and fifty (1:350) reverse stock split effected on November 6, 2017 and a one-for-five hundred (1:500) reverse stock split effected on May 2, 2018.
[2]	reflects a one-for-three hundred and fifty (1:350) reverse stock split effected on November 6, 2017 and a one-for-five hundred (1:500) reverse stock split effected on May 2, 2018.

Net Loss per Common Share - Ant

Net Loss per Common Share - Anti-Dilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	3,232,551	193,988	14,049	41	63
Stock Options [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)		55,846
Unvested Restricted Shares [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)		101,294
Warrants [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	2,116,296	36,848	14,049	41	65
Assumed Conversion of Convertible Notes [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	1,116,255

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw materials	$ 339	$ 298	$ 346
Work-in-process	755	721	214
Finished goods	156	229	100
Total inventories	$ 1,250	$ 1,248	$ 660

Prepaid Expenses and Other Cu44

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Prepaid Expense And Other Assets Current [Abstract]
Insurance premiums	$ 168	$ 421	$ 501
Security deposit	50	50	50
VAT/GST receivable	37	29
Software	26	15
Financing costs	25	70
Other	76	115
Other		159	147
Total prepaid expenses and other current assets	$ 382	$ 700	$ 698

Prepaid Expenses and Other Cu45

Prepaid Expenses and Other Current Assets - Additional Information (Detail)	Jun. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Prepaid Expense And Other Assets Current [Abstract]
Maximum percentage of prepaid expenses and other current assets (in hundredths)	5.00%	5.00%	5.00%

Property, Plant, and Equipmen46

Property, Plant, and Equipment - Components of Property, Plant, and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 5,202	$ 5,174	$ 4,886
Accumulated depreciation	(4,103)	(3,876)	(3,803)
Property, plant and equipment, net	1,099	1,298	1,083
Buildings and Land [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	579	579	556
Enterprise Hardware and Software [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	1,743	1,744	1,532
Leaseholds [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	1,702	1,705	1,504
Equipment [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	979	971	940
Furniture [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 199	$ 175	$ 354

Property, Plant, and Equipmen47

Property, Plant, and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Depreciation expense	$ 100	$ 100	$ 236	$ 127	$ 310	$ 305	$ 617

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Compensation, excluding taxes	$ 1,573	$ 869	$ 1,365
Clinical trial expenses	2,304	1,124	933
Professional fees	314	221	286
Short-term portion of lease restructuring	193	209	216
Other	836	985	607
Total accrued expenses	$ 5,220	$ 3,408	$ 3,407

Accrued Expenses - Schedule o49

Accrued Expenses - Schedule of Accrued Expenses (Parenthetical) (Detail)	Jun. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Maximum percentage of current liabilities accrued (in hundredths)	5.00%	5.00%	5.00%

Restructuring Expenses - Additi

Restructuring Expenses - Additional Information (Detail) $ in Thousands	Aug. 18, 2014USD ($)	May 22, 2014USD ($)	Jun. 30, 2018USD ($)Lease	Dec. 31, 2017USD ($)Lease	Dec. 31, 2016USD ($)
Lease Liability [Member]
Restructuring Cost And Reserve [Line Items]
Number of sub leases | Lease			2	2
Restructuring reserve charges			$ 0	$ 0
Restructuring reserve balance			$ 495	604	$ 820
Sub-lease 1 [Member] | Facility Closing [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring reserve charges		$ 900
Sub Lease 2 [Member] | Facility Closing [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring reserve charges	$ 700
Other non-current liabilities [Member] | Lease Liability [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring reserve balance				400
Accrued Expenses [Member] | Lease Liability [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring reserve balance				$ 200

Restructuring Expenses - Schedu

Restructuring Expenses - Schedule of Restructuring and Related Costs (Detail) - Lease Liability [Member] - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Restructuring Cost And Reserve [Line Items]
Restructuring reserve balance	$ 604	$ 820
Charges	0	0
Payments/Utilizations	(109)	(216)
Restructuring reserve balance	$ 495	$ 604

Secured Convertible Notes Pay52

Secured Convertible Notes Payable and Common Stock Purchase Warrants - Additional Information (Detail)

Jun. 04, 2018USD ($)$ / sharesshares

May 02, 2018

Dec. 28, 2017USD ($)

Nov. 15, 2017USD ($)$ / sharesshares

Nov. 06, 2017

Oct. 11, 2017USD ($)d$ / sharesshares

Oct. 10, 2017USD ($)Investorshares

Sep. 21, 2017USD ($)$ / shares

Sep. 15, 2017USD ($)$ / sharesshares

Aug. 28, 2017USD ($)$ / sharesshares

Aug. 04, 2017USD ($)$ / shares

Jul. 07, 2017USD ($)$ / shares

Jul. 02, 2017USD ($)$ / shares

May 09, 2017USD ($)$ / shares

Apr. 10, 2017USD ($)$ / shares

Apr. 02, 2017USD ($)

Mar. 13, 2017USD ($)$ / shares

Mar. 02, 2017USD ($)$ / shares

Feb. 10, 2017USD ($)$ / shares

Feb. 01, 2017USD ($)$ / shares

Jan. 12, 2017USD ($)$ / shares

Jul. 21, 2016

Jul. 19, 2016

Jun. 13, 2016

Jun. 06, 2016USD ($)Installment$ / sharesshares

Dec. 31, 2016USD ($)$ / shares

Jun. 30, 2016USD ($)

Jun. 30, 2018USD ($)

Jun. 30, 2017USD ($)

Jun. 30, 2018USD ($)

Jun. 30, 2017USD ($)

Dec. 31, 2017USD ($)$ / sharesshares

Dec. 28, 2017USD ($)

Dec. 31, 2016USD ($)$ / shares

Dec. 31, 2015USD ($)$ / shares

Dec. 31, 2014$ / shares

Debt Instrument [Line Items]

Gain (loss) on warrant extinguishment

$ (21,000,000)

$ 0

$ 9,613,000

$ 0

$ 9,613,000

$ 9,613,000

$ 0

$ 0

Warrant liability fair value adjustment

(2,513,000)

$ 38,000

(17,209,000)

(1,200,000)

(15,103,000)

(12,780,000)

(564,000)

Debt instrument, conversion price | $ / shares

$ 5,250

$ 12,250

$ 8,750

$ 10,500

$ 19,250

$ 24,500

$ 35,000

$ 56,000

$ 63,000

Debt discount amortization

238,000

15,277,000

Reverse stock split ratio

0.0020

0.0029

0.0625

Conversion of convertible notes

$ 1,015,848

$ 2,000,000

$ 1,913,915

$ 3,621,286

$ 4,417,829

$ 125,999

$ 3,045,817

$ 544,000

$ 1,478,318

0

15,831,000

40,121,000

$ 35,000,000

649,000

$ 0

Debt instrument extended prepayment date

Mar. 31, 2018

Derivative liability, at calculated fair value

$ 4,900,000

4,900,000

Fair value of beneficial conversion feature of convertible note

$ 4,908,000

$ 4,435,000

Minimum [Member]

Debt Instrument [Line Items]

Reverse stock split ratio

0.1

Exercise price of warrants | $ / shares

$ 281,750

$ 1,225

$ 281,750

$ 2,072,000

$ 4,900,000

Maximum [Member]

Debt Instrument [Line Items]

Reverse stock split ratio

0.05

Exercise price of warrants | $ / shares

$ 19,712,000

$ 19,712,000

$ 19,712,000

$ 19,712,000

$ 19,712,000

Additional Paid in Capital [Member]

Debt Instrument [Line Items]

Fair value of beneficial conversion feature of convertible note

$ 4,908,000

$ 4,435,000

Series A Preferred Stock [Member]

Debt Instrument [Line Items]

Preferred stock redemption price per share | $ / shares

$ 0.001

Series C Preferred Shares [Member]

Debt Instrument [Line Items]

Preferred stock redemption price per share | $ / shares

$ 1,000

Payment for redemption of preferred stock

$ 590,000

0

$ 0

Conversion of convertible notes

$ 500,000

Restructuring Agreement [Member]

Debt Instrument [Line Items]

Gain (loss) on warrant extinguishment

$ (2,300,000)

Initial release of restricted cash

$ 1,650,000

Conversion of convertible notes

$ 1,200,000

Restructuring Agreement [Member] | Series A Preferred Stock [Member]

Debt Instrument [Line Items]

Preferred stock redemption price per share | $ / shares

$ 4.20

Restructuring Agreement [Member] | Series B Preferred Stock [Member]

Debt Instrument [Line Items]

Payment for redemption of preferred stock

$ 2,006,000

Restructuring Agreement [Member] | Investor [Member] | Series A Preferred Stock [Member]

Debt Instrument [Line Items]

Number of preferred stock | shares

4,200

Restructuring Agreement [Member] | Investor [Member] | Series B Convertible Preferred Stock [Member]

Debt Instrument [Line Items]

Number of preferred stock | shares

2,006

Restructuring Agreement [Member] | Investor [Member] | Notes [Member]

Debt Instrument [Line Items]

Aggregate principal amount of notes

$ 11,444,637

Additional Restructuring [Member]

Debt Instrument [Line Items]

Shares issuable upon warrants exercised | shares

2,125

Reverse stock split ratio

20

Gain (loss) on warrant extinguishment

$ 1,900,000

Loss on debt settlement

$ 1,200,000

Additional Restructuring [Member] | New Warrants [Member]

Debt Instrument [Line Items]

Warrants term

42 months

Exercise price of warrants | $ / shares

$ 61,250

Amendment to Restructuring Agreement [Member]

Debt Instrument [Line Items]

Shares issuable upon warrants exercised | shares

735

Warrants term

4 years 6 months

Exercise price of warrants | $ / shares

$ 61,250

Loss on debt settlement

$ 300,000

Warrants issued to purchase Common Stock | shares

127,551

225

255

Extinguishment of remaining outstanding obligations under notes

$ 300,000

$ 2,300,000

Loss on debt settlements by issuing warrants

300,000

Amendment to Restructuring Agreement [Member] | Series C Preferred Shares [Member]

Debt Instrument [Line Items]

Redemption of shares outstanding for cash payment

$ 590,000

Exchange Agreement [Member]

Debt Instrument [Line Items]

Aggregate principal amount of notes

$ 10,562,425

Warrants term

5 years

Exercise price of warrants | $ / shares

$ 1,225

Number of Notes investors entered into agreement

2

2

2

Warrants issued to purchase Common Stock | shares

14,000

Extinguishment of remaining outstanding obligations under notes

$ 3,000,000

Debt instrument date of agreement

Dec. 28, 2017

Nov. 15, 2017

Release of restrictions on restricted cash held in control accounts

$ 2,046,898

Cash payment to investors from restricted cash held

829,831

Loss on debt settlements by issuing shares and debt

$ 3,700,000

Exchange Agreement [Member] | Minimum [Member]

Debt Instrument [Line Items]

Percentage of beneficial ownership by investor of issued and outstanding stock

4.90%

Exchange Agreement [Member] | Maximum [Member]

Debt Instrument [Line Items]

Percentage of beneficial ownership by investor of issued and outstanding stock

9.90%

Securities Purchase Agreement [Member] | Warrant Repurchase Agreements [Member]

Debt Instrument [Line Items]

Aggregate amount to be paid in exchange for cancellation of warrants

$ 7,900,000

$ 7,900,000

Gain (loss) on warrant extinguishment

9,600,000

Warrant liability fair value adjustment

$ 17,500,000

Series C Warrants [Member]

Debt Instrument [Line Items]

Aggregate amount to be paid in exchange for cancellation of warrants

0

7,876,000

$ 7,876,000

0

0

Release of restrictions on restricted cash held in control accounts

$ 0

$ 7,876,000

$ 7,876,000

$ 0

$ 0

Series C Warrants [Member] | Securities Purchase Agreement [Member]

Debt Instrument [Line Items]

Additional issuance of common stock purchase price per share | $ / shares

$ 0.01

Series C Warrants [Member] | Securities Purchase Agreement [Member] | Warrant Repurchase Agreements [Member]

Debt Instrument [Line Items]

Aggregate amount to be paid in exchange for cancellation of warrants

7,900,000

Series D Warrants [Member] | Securities Purchase Agreement [Member]

Debt Instrument [Line Items]

Debt discount on senior notes

$ 2,300,000

Debt issuance expense

$ 2,800,000

Series D-1 Warrants [Member] | Securities Purchase Agreement [Member]

Debt Instrument [Line Items]

Shares issuable upon warrants exercised | shares

1,100,000

Warrants term

5 years

Exercise price of warrants | $ / shares

$ 4

Series D-2 [101-113] Warrants [Member] | Securities Purchase Agreement [Member]

Debt Instrument [Line Items]

Shares issuable upon warrants exercised | shares

13,000,000

Warrants term

5 years

Exercise price of warrants | $ / shares

$ 0.01

Buy back of warrants, description

The Company may buy back each D-2 Warrant on its date of initial exercisability so long as the Company is not in default and the applicable installment payment for each month commencing on January 4, 2019 through December 4, 2019 has been paid when due.

Warrants exercisable, description

D-2 Warrants have a five-year term from initial exercisability which begins on the fifth day of each month commencing December 5, 2018, through December 5, 2019, for each of Warrant D-2-101 through 113 respectively.

Warrants exercisable, start date

Dec. 5, 2018

Warrants exercisable, end date

Dec. 5, 2019

Senior Secured Convertible Notes [Member] | Series A Preferred Stock [Member]

Debt Instrument [Line Items]

Conversion of convertible notes

$ 4,200,000

Senior Secured Convertible Notes [Member] | Amendment to Restructuring Agreement [Member]

Debt Instrument [Line Items]

Debt instrument, conversion price | $ / shares

$ 0.05

Number of Notes investors entered into agreement | Investor

2

Conversion of convertible notes

$ 279,015

Conversion price of debt instrument to purchase price of common stock percentage.

200.00%

Debt instrument, maturity description

The maturity date (as defined in the notes) shall automatically be extended to the earlier to occur of (x) the first anniversary of the date of consummation of the offering contemplated by the registration statement and (y) December 30, 2018

Debt instrument maturity date

Dec. 30, 2018

Debt instrument, deferred description

until the earlier of (x) this maturity date and (y) the 75th calendar day after the date of consummation of the offering contemplated by the registration statement, all installments to be made under the notes shall be deemed automatically deferred with no conversions during that 75 day period

Debt instrument, conversion treshhold days | d

75

Debt instrument, redemption description

The Company agreed to redeem any portion of the outstanding notes at any time requested by either investor thereto with $7.3 million in cash to be reduced by $0.6 million to redeem the Series C Preferred Stock remaining in the restricted accounts with respect to the 2016 convertible notes

Redemption of outstanding debt instrument for cash

$ 7,300,000

Senior Secured Convertible Notes [Member] | Amendment to Restructuring Agreement [Member] | Series C Preferred Shares [Member]

Debt Instrument [Line Items]

Cash held in the restricted accounts

$ 600,000

Senior Secured Convertible Notes [Member] | Exchange Agreement [Member]

Debt Instrument [Line Items]

Debt instrument, principal face amount

$ 10,600,000

Gain (loss) on warrant extinguishment

(19,000,000)

Aggregate principal amount of notes

11,157,970

Fair value of new notes including conversion feature

15,200,000

Debt instrument, fair value

10,300,000

Senior Secured Convertible Notes [Member] | Exchange Agreement [Member] | Additional Paid in Capital [Member]

Debt Instrument [Line Items]

Fair value of beneficial conversion feature of convertible note

$ 4,900,000

Senior Secured Convertible Notes [Member] | Securities Purchase Agreement [Member]

Debt Instrument [Line Items]

Debt instrument, principal face amount

$ 35,000,000

Debt discount on senior notes

$ 2,800,000

$ 35,000,000

Proceeds from issuance of notes available for general corporate purposes

$ 3,000,000

Amortization payments number of equal installments | Installment

14

Period after original date of issuance of notes for which amortization payment begins

7 months

Debt instrument, original issuance date

Jun. 13, 2016

Debt instrument, conversion price | $ / shares

$ 3

$ 8,537,775

Beneficial conversion feature

4,400,000

Debt discount amortization

35,000,000

Debt issuance costs

$ 2,200,000

Interest rate

8.00%

Maximum required market price of common shares, to settle notes payable in cash | $ / shares

$ 3

Notes payable terms

The Notes bear 8% interest payable quarterly in cash. $2.5 million matures in six months; $0.8 million is payable in twelve installments beginning [seven (7)] months after the original issuance date.

Senior Secured Convertible Notes [Member] | Securities Purchase Agreement [Member] | Matures in Six Months [Member]

Debt Instrument [Line Items]

Notes payable maturity amount

$ 2,500,000

Senior Secured Convertible Notes [Member] | Securities Purchase Agreement [Member] | Payable in Twelve Installments Beginning Seven Months After Original Issuance Date [Member]

Debt Instrument [Line Items]

Notes payable maturity amount

800,000

Senior Secured Convertible Notes [Member] | Series C Warrants [Member]

Debt Instrument [Line Items]

Debt instrument, principal face amount

$ 35,000,000

Senior Secured Convertible Notes [Member] | Series C Warrants [Member] | Securities Purchase Agreement [Member]

Debt Instrument [Line Items]

Proceeds from issuance of notes and warrants

$ 32,200,000

Debt discount on senior notes

$ 27,800,000

Shares issuable upon warrants exercised | shares

40

Senior Secured Convertible Notes [Member] | Warrants [Member] | Exchange Agreement [Member]

Debt Instrument [Line Items]

Derivative liability, at calculated fair value

$ 14,400,000

Senior Secured Convertible Notes [Member] | Series D Warrants [Member] | Securities Purchase Agreement [Member]

Debt Instrument [Line Items]

Debt instrument, principal face amount

3,300,000

Proceeds from issuance of notes and warrants

2,400,000

Debt discount on senior notes

$ 1,100,000

Restricted Notes [Member] | Restructuring Agreement [Member] | Investor [Member] | Notes [Member]

Debt Instrument [Line Items]

Aggregate principal amount of notes

10,092,857

Unrestricted Notes [Member] | Restructuring Agreement [Member] | Investor [Member] | Notes [Member]

Debt Instrument [Line Items]

Aggregate principal amount of notes

1,351,780

Cancellation Note [Member] | Restructuring Agreement [Member]

Debt Instrument [Line Items]

Aggregate principal of notes cancelled

$ 1,200,000

Redemption Notes [Member] | Additional Restructuring [Member]

Debt Instrument [Line Items]

Debt instrument, principal face amount

$ 4,000,000

Debt instrument, redemption price

6,436,852.80

Exchange Notes [Member] | Additional Restructuring [Member]

Debt Instrument [Line Items]

Debt instrument, principal face amount

$ 2,436,852.80

Exchange Notes [Member] | Additional Restructuring [Member] | New Warrants [Member]

Debt Instrument [Line Items]

Common stock shares purchased | shares

114,286

New Notes [Member] | Exchange Agreement [Member]

Debt Instrument [Line Items]

Debt instrument, conversion price | $ / shares

$ 750

Extinguishment of remaining outstanding obligations under notes

$ 3,027,408

Debt instrument conversion price of lowest vwap for common stock percentage

82.00%

Debt instrument conversion price of lowest vwap for common stock in event of default percentage

75.00%

Convertible Notes Payable - Sum

Convertible Notes Payable - Summary of Common Stock and Preferred Stock Shares Issued under Notes and New Notes (Detail) - USD ($)	Dec. 28, 2017	Nov. 15, 2017	Nov. 06, 2017	Aug. 28, 2017	Aug. 04, 2017	Jul. 07, 2017	Jul. 02, 2017	Jun. 07, 2017	May 09, 2017	Apr. 10, 2017	Mar. 13, 2017	Mar. 02, 2017	Feb. 10, 2017	Feb. 01, 2017	Jan. 12, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Dec. 28, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Applicable Conversion Price					$ 5,250	$ 12,250			$ 8,750	$ 10,500	$ 19,250	$ 24,500	$ 35,000	$ 56,000	$ 63,000
Reduction in Principal					$ 1,015,848	$ 2,000,000			$ 1,913,915	$ 3,621,286	$ 4,417,829	$ 125,999	$ 3,045,817	$ 544,000	$ 1,478,318	$ 0	$ 15,831,000	$ 40,121,000	$ 35,000,000	$ 649,000	$ 0
Exchange Agreement [Member]
Debt Instrument [Line Items]
Number of Shares	247,417
Applicable Conversion Price	$ 10	$ 41.72					$ 12,250	$ 12,250											$ 10
Reduction in Principal	$ 2,474,174	$ 8,130,564					$ 4,200,000	$ 4,200,000
Restructuring Agreement [Member]
Debt Instrument [Line Items]
Applicable Conversion Price				$ 5,250
Reduction in Principal				$ 1,200,000
Warrant Exchange [Member]
Debt Instrument [Line Items]
Reduction in Principal			$ 279,016
Retirement Exchange Agreement [Member]
Debt Instrument [Line Items]
Reduction in Principal	$ 553,234
Common Stock Issued [Member]
Debt Instrument [Line Items]
Number of Shares					83	229			218	344	229	5	87	10	23				642,885
Common Stock Issued [Member] | Exchange Agreement [Member]
Debt Instrument [Line Items]
Number of Shares	445,152	194,896					1,380	1,380
Common Stock Issued [Member] | Restructuring Agreement [Member]
Debt Instrument [Line Items]
Number of Shares				229
Preferred Stock Issued [Member] | Exchange Agreement [Member]
Debt Instrument [Line Items]
Number of Shares							4,200	4,200

Convertible Notes Payable - S54

Convertible Notes Payable - Summary of Common Stock and Preferred Stock Shares Issued under Notes and New Notes (Parenthetical) (Detail) - USD ($)	Dec. 28, 2017	Nov. 15, 2017	Oct. 10, 2017	Aug. 28, 2017	Aug. 04, 2017	Jul. 07, 2017	Jul. 02, 2017	Jun. 07, 2017	May 09, 2017	Apr. 10, 2017	Mar. 13, 2017	Mar. 02, 2017	Feb. 10, 2017	Feb. 01, 2017	Jan. 12, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Dec. 28, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Reduction in Principal					$ 1,015,848	$ 2,000,000			$ 1,913,915	$ 3,621,286	$ 4,417,829	$ 125,999	$ 3,045,817	$ 544,000	$ 1,478,318			$ 0	$ 15,831,000	$ 40,121,000	$ 35,000,000	$ 649,000	$ 0
Gain (loss) on warrant extinguishment		$ (21,000,000)														$ 0	$ 9,613,000	$ 0	$ 9,613,000	$ 9,613,000		$ 0	$ 0
Exchange Agreement [Member]
Debt Instrument [Line Items]
Number of shares issued	247,417
Reduction in Principal	$ 2,474,174	$ 8,130,564					$ 4,200,000	$ 4,200,000
Gain (loss) on warrant extinguishment	(3,700,000)
Loss on debt settlement							$ 1,000,000
Series A Preferred Stock [Member]
Debt Instrument [Line Items]
Number of shares issued							4,200
Restructuring Agreement [Member]
Debt Instrument [Line Items]
Reduction in Principal				$ 1,200,000
Gain (loss) on warrant extinguishment			$ (2,300,000)
Loss on debt settlement				$ 1,900,000
Retirement Per Exchange Agreement [Member] | Exchange Agreement [Member]
Debt Instrument [Line Items]
Reduction in Principal	$ 600,000
Common Stock Issued [Member]
Debt Instrument [Line Items]
Number of shares issued					83	229			218	344	229	5	87	10	23						642,885
Common Stock Issued [Member] | Exchange Agreement [Member]
Debt Instrument [Line Items]
Number of shares issued	445,152	194,896					1,380	1,380
Common Stock Issued [Member] | Restructuring Agreement [Member]
Debt Instrument [Line Items]
Number of shares issued				229
Provision To Exchange [Member] | Exchange Agreement [Member]
Debt Instrument [Line Items]
Number of shares issued		1,948
Reduction in Principal		$ 600,000
Updated Conversion Price Formula [Member] | Exchange Agreement [Member]
Debt Instrument [Line Items]
Number of shares issued		192,948
Reduction in Principal		$ 7,500,000

Stockholders' Equity - Reverse

Stockholders' Equity - Reverse Stock Split - Additional Information (Detail)	May 02, 2018$ / sharesshares	Nov. 06, 2017$ / sharesshares	Jul. 21, 2016$ / sharesshares	Jul. 19, 2016shares	Jun. 30, 2018$ / sharesshares	Dec. 31, 2017$ / sharesshares	Dec. 31, 2016$ / sharesshares
Stockholders Equity Note [Line Items]
Reverse stock split ratio	0.0020	0.0029	0.0625
Number of fractional shares were issued in connected with the reverse stock split			0
Common stock, par value (in dollars per share) | $ / shares			$ 0.01		$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)				170,000,000	1,000,000,000	1,000,000,000	500,000,000
Reverse stock split	1:500	1:350
Minimum [Member]
Stockholders Equity Note [Line Items]
Reverse stock split ratio				0.1
Maximum [Member]
Stockholders Equity Note [Line Items]
Reverse stock split ratio				0.05
Previously Reported [Member]
Stockholders Equity Note [Line Items]
Common stock, shares authorized (in shares)						500,000,000
OTCQB [Member]
Stockholders Equity Note [Line Items]
Reverse stock split ratio	0.0020	0.0029
Number of fractional shares were issued in connected with the reverse stock split	0	0
Common stock, par value (in dollars per share) | $ / shares	$ 0.01	$ 0.01
Reverse stock split	1:500

Stockholders' Equity - Preferre

Stockholders' Equity - Preferred Stock Issuances - Additional Information (Detail)	Sep. 21, 2017USD ($)InvestorVote$ / sharesshares	Aug. 28, 2017USD ($)shares	Aug. 04, 2017USD ($)	Jul. 11, 2017USD ($)Vote$ / shares	Jul. 07, 2017USD ($)	Jul. 02, 2017USD ($)Vote$ / sharesshares	May 09, 2017USD ($)	Apr. 10, 2017USD ($)	Mar. 13, 2017USD ($)	Mar. 02, 2017USD ($)	Feb. 10, 2017USD ($)	Feb. 01, 2017USD ($)	Jan. 12, 2017USD ($)	Oct. 31, 2016USD ($)	Feb. 28, 2015USD ($)	Oct. 31, 2013USD ($)	Jun. 30, 2018USD ($)$ / shares	Dec. 31, 2017USD ($)$ / shares	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)$ / shares	Dec. 28, 2017USD ($)	Dec. 31, 2016USD ($)$ / shares	Dec. 31, 2015USD ($)	Nov. 06, 2017USD ($)	Sep. 12, 2017$ / shares	Jun. 29, 2017$ / shares
Stockholders Equity Note [Line Items]
Preferred stock, par value (in dollars per share) | $ / shares																	$ 0.01	$ 0.01		$ 0.01		$ 0.01
Conversion of convertible notes			$ 1,015,848		$ 2,000,000		$ 1,913,915	$ 3,621,286	$ 4,417,829	$ 125,999	$ 3,045,817	$ 544,000	$ 1,478,318				$ 0		$ 15,831,000	$ 40,121,000	$ 35,000,000	$ 649,000	$ 0
Sale of stock in private placement																	$ 4,210,000					1,011,000	8,479,000
Gross proceeds from the sale of shares														$ 1,200,000	$ 2,600,000	$ 7,500,000
Deemed dividend amount																				$ 527,000		$ 0	$ 0
Restructuring Agreement [Member]
Stockholders Equity Note [Line Items]
Conversion of convertible notes		$ 1,200,000
Series A Preferred Stock [Member]
Stockholders Equity Note [Line Items]
Preferred stock, par value (in dollars per share) | $ / shares																										$ 0.01
Number of Shares | shares						4,200
Closing bid price | $ / shares						$ 644,000
Number of votes | Vote						4,200,000
Preferred stock redemption price per share | $ / shares						$ 0.001
Series A Preferred Stock [Member] | Senior Secured Convertible Notes [Member]
Stockholders Equity Note [Line Items]
Conversion of convertible notes						$ 4,200,000
Series B Preferred Stock [Member]
Stockholders Equity Note [Line Items]
Preferred stock, par value (in dollars per share) | $ / shares																										$ 0.01
Closing bid price | $ / shares				$ 32,787
Number of votes | Vote				61
Sale of stock in private placement				$ 2,360,000
Cash purchase price in private placement				2,000,000
Gross proceeds from the sale of shares				$ 2,000,000
Conversion price per share | $ / shares				$ 26,775
Deemed dividend amount																		$ 360,000
Series B Preferred Stock [Member] | Restructuring Agreement [Member]
Stockholders Equity Note [Line Items]
Redeemed share | shares		2,360,000
Series C Preferred Shares [Member]
Stockholders Equity Note [Line Items]
Preferred stock, par value (in dollars per share) | $ / shares																									$ 0.01
Number of Shares | shares	590
Number of votes | Vote	2,968
Preferred stock redemption price per share | $ / shares	$ 1,000
Conversion of convertible notes	$ 500,000
Number of investors | Investor	2
Redemption of preferred stock																								$ 590,000

Stockholders' Equity - Stock an

Stockholders' Equity - Stock and Warrant Issuances - Additional Information (Detail)

Oct. 11, 2017shares

Oct. 10, 2017shares

Apr. 02, 2017USD ($)

Nov. 30, 2016USD ($)Investorshares

Oct. 31, 2016USD ($)shares

Jun. 30, 2016USD ($)shares

Jul. 31, 2015USD ($)shares

Feb. 28, 2015USD ($)shares

Oct. 31, 2013USD ($)shares

Jun. 30, 2018USD ($)$ / sharesshares

Jun. 30, 2017USD ($)

Dec. 31, 2017USD ($)Investor$ / sharesshares

Dec. 31, 2016USD ($)$ / sharesshares

Dec. 31, 2015USD ($)$ / sharesshares

Nov. 30, 2017USD ($)

Jun. 06, 2016USD ($)shares

Oct. 20, 2015USD ($)

Dec. 31, 2014$ / sharesshares

Stockholders Equity Note [Line Items]

Sale of common stock, net of expenses (in shares)

2

3,000,000

1

1

424,000

Proceeds from issuance of private placement | $

$ 1,200,000

$ 2,600,000

$ 7,500,000

Net proceeds from issuance of private placement | $

$ 1,100,000

$ 2,500,000

$ 6,900,000

$ 4,300,000

Number of warrants outstanding (in shares)

14,049

78

44

9

Sale of units to underwriter

3,000,000

Proceeds of common stock issued, net of related expenses | $

$ 6,000,000

Number of pre-funded warrants

76,000

Maximum [Member]

Stockholders Equity Note [Line Items]

Warrants exercisable per share price (in dollars per share) | $ / shares

$ 19,712,000

$ 19,712,000

$ 19,712,000

$ 19,712,000

Maximum offering and selling of stock and securities that entity make to raise capital | $

$ 71,800,000

Common Stock Issued [Member]

Stockholders Equity Note [Line Items]

Sale of common stock, net of expenses (in shares)

668,854

2

4

Common shares and rights issued

227,287

10

Amendment to Restructuring Agreement [Member]

Stockholders Equity Note [Line Items]

Warrants issued to purchase Common Stock

127,551

225

255

Warrants exercisable per share price (in dollars per share) | $ / shares

$ 61,250

Number of warrants outstanding (in shares)

10

Warrants term

4 years 6 months

Warrants exercised (in shares)

3

Number of investors | Investor

2

Shares issuable upon warrants exercised

735

Warrants exercise price description

The warrants contain a cashless exercise provision that allows the holders to exercise each warrant for three shares of common stock.

Securities Purchase Agreement [Member] | Common Stock Issued [Member]

Stockholders Equity Note [Line Items]

Common shares and rights issued

224,000

Securities Purchase Agreement [Member] | Warrant Repurchase Agreements [Member]

Stockholders Equity Note [Line Items]

Aggregate amount to be paid in exchange for cancellation of warrants | $

$ 7,900,000

$ 7,900,000

Senior Secured Convertible Notes [Member] | Securities Purchase Agreement [Member]

Stockholders Equity Note [Line Items]

Debt instrument, principal face amount | $

$ 35,000,000

Senior Secured Convertible Notes [Member] | Securities Purchase Agreement [Member] | Common Stock Issued [Member]

Stockholders Equity Note [Line Items]

Common shares and rights issued

217,800

Series A Common Stock Warrants [Member]

Stockholders Equity Note [Line Items]

Warrants exercisable per share price (in dollars per share) | $ / shares

$ 24,500

Number of warrants outstanding (in shares)

9,000,000

Number of warrants converted

8,000,000

Gross proceeds from underwriting offering | $

$ 7,000,000

Warrants exercised (in shares)

1,000,000

Net proceeds from exercise of warrants | $

$ 400,000

Series A And B Common Stock Warrants [Member]

Stockholders Equity Note [Line Items]

Value of warrants issued | $

$ 3,400,000

Series B Common Stock Warrants [Member]

Stockholders Equity Note [Line Items]

Warrants exercised (in shares)

1,000,000

Net proceeds from exercise of warrants | $

$ 800,000

Remaining outstanding warrants expired

3,000,000

Warrants expiration date

Jan. 29, 2016

Expected Life [Member]

Stockholders Equity Note [Line Items]

Warrants term

5 years

Expected Life [Member] | Maximum [Member]

Stockholders Equity Note [Line Items]

Warrants term

6 years 4 months 24 days

4 years 10 months 17 days

'Expected Volatility [Member]

Stockholders Equity Note [Line Items]

Warrants measurement input

1.9410

'Expected Volatility [Member] | Maximum [Member]

Stockholders Equity Note [Line Items]

Warrants measurement input

3.7200

2.6692

Risk-free Interest Rates [Member]

Stockholders Equity Note [Line Items]

Warrants measurement input

0.0278

Risk-free Interest Rates [Member] | Maximum [Member]

Stockholders Equity Note [Line Items]

Warrants measurement input

0.0292

0.0206

February 2018 Warrants [Member]

Stockholders Equity Note [Line Items]

Warrants issued to purchase Common Stock

1,000,000

Value of warrants issued | $

$ 18,300,000

Warrants exercisable per share price (in dollars per share) | $ / shares

$ 10

Number of warrants outstanding (in shares)

1,000,000

February 2018 Warrants [Member] | Exercise Price [Member]

Stockholders Equity Note [Line Items]

Warrants measurement input | $ / shares

10

February 2018 Warrants [Member] | Expected Life [Member]

Stockholders Equity Note [Line Items]

Warrants term

6 years

February 2018 Warrants [Member] | 'Expected Volatility [Member]

Stockholders Equity Note [Line Items]

Warrants measurement input

1.2268

February 2018 Warrants [Member] | Risk-free Interest Rates [Member]

Stockholders Equity Note [Line Items]

Warrants measurement input

0.01

2013 Warrants [Member]

Stockholders Equity Note [Line Items]

Warrants issued to purchase Common Stock

9

Value of warrants issued | $

$ 1,900,000

Warrants exercisable per share price (in dollars per share) | $ / shares

$ 19,712,000

Number of warrants outstanding (in shares)

9

Warrants term

5 years

February 2015 Warrants [Member]

Stockholders Equity Note [Line Items]

Warrants issued to purchase Common Stock

9

Value of warrants issued | $

$ 800,000

Warrants exercisable per share price (in dollars per share) | $ / shares

$ 24,500

Number of warrants outstanding (in shares)

9

Warrants term

5 years

Series C Warrants [Member]

Stockholders Equity Note [Line Items]

Aggregate amount to be paid in exchange for cancellation of warrants | $

$ 0

$ 7,876,000

$ 7,876,000

$ 0

$ 0

Series C Warrants [Member] | Securities Purchase Agreement [Member]

Stockholders Equity Note [Line Items]

Value of warrants issued | $

27,800,000

Series C Warrants [Member] | Securities Purchase Agreement [Member] | Warrant Repurchase Agreements [Member]

Stockholders Equity Note [Line Items]

Aggregate amount to be paid in exchange for cancellation of warrants | $

7,900,000

Series C Warrants [Member] | Senior Secured Convertible Notes [Member]

Stockholders Equity Note [Line Items]

Debt instrument, principal face amount | $

$ 35,000,000

Series C Warrants [Member] | Senior Secured Convertible Notes [Member] | Securities Purchase Agreement [Member]

Stockholders Equity Note [Line Items]

Number of warrants converted

40

Shares issuable upon warrants exercised

40

October 2016 Warrants [Member]

Stockholders Equity Note [Line Items]

Warrants issued to purchase Common Stock

1

Value of warrants issued | $

$ 300,000

Warrants exercisable per share price (in dollars per share) | $ / shares

$ 24,500

Number of warrants outstanding (in shares)

1

Warrants term

5 years

Net proceeds from exercise of warrants | $

$ 100,000

November 2017 Warrants [Member] | Exchange Agreement [Member]

Stockholders Equity Note [Line Items]

Warrants issued to purchase Common Stock

14,049

Value of warrants issued | $

$ 14,400,000

$ 14,400,000

Warrants exercisable per share price (in dollars per share) | $ / shares

$ 1,225

Number of warrants outstanding (in shares)

14,049

Warrants term

5 years

Number of investors | Investor

2

Stockholders' Equity - Stock In

Stockholders' Equity - Stock Incentive Plans - Additional Information (Detail) - USD ($)		May 02, 2018	Jul. 31, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option compensation (income) expense						$ (40,000)	$ 46,000	$ 50,000	$ 161,000	$ 349,000
Stock options granted	[1]							0	0	0
Additional compensation expense relating to stock options								$ 6,800
Restricted stock compensation (income) expense						(81,000)	64,000	79,000	$ 266,000	$ 308,000
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option compensation (income) expense				$ (47,000)	$ 24,000	(40,000)	46,000	$ 100,000	$ 200,000	300,000
Stock options granted									0
Remaining average recognition period for unrecognized compensation expense								5 months 1 day
Aggregate intrinsic value of options outstanding and exercisable								$ 0
Closing stock price (in dollars per share)								$ 450
Stock Options [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options granted, term								10 years
Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock compensation (income) expense				$ (94,000)	$ 6,000	$ (81,000)	$ 100,000	$ 100,000	$ 300,000	$ 300,000
2004 Stock Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for the issuance (in shares)								0
2009 Stock Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for the issuance (in shares)			0					0
Increased number of shares (in shares)			0
Shares available for grant								0
Subsequent Event [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for grant		0
Stock options granted		0
[1]	Due to the May 2, 2018 1-for-500 reverse stock split, and no fractional shares being issued, all numbers are reduced to zero.

Stockholders' Equity - Stock Op

Stockholders' Equity - Stock Option Activity (Detail) - $ / shares		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock Options, Number of Options [Roll Forward]
Outstanding, beginning of period (in shares)	[1]	0	0	0
Granted (in shares)	[1]	0	0	0
Forfeited (in shares)	[1]	0	0	0
Outstanding, end of period (in shares)	[1]	0	0	0	0
Exercisable (in shares)	[1]	0
Stock Options, Exercise Price per Share [Roll Forward]
Granted (in dollars per share)	[1]	$ 0		$ 0
Forfeited (in dollars per share)	[1]	0
Stock Options, Weighted Average Exercise Price [Roll Forward]
Outstanding, beginning of period (in dollars per share)	[1]	0	$ 0	0
Granted (in dollars per share)	[1]	0		0
Forfeited (in dollars per share)	[1]	0	0	0
Outstanding, end of period (in dollars per share)	[1]	0	$ 0	$ 0	$ 0
Exercisable (in dollars per share)	[1]	$ 0
Stock Options, Weighted Average Remaining Life Years [Abstract]
Outstanding	[1]	0 years	0 years	0 years	0 years
Exercisable	[1]	0 years
Minimum [Member]
Stock Options, Exercise Price per Share [Roll Forward]
Outstanding, beginning of period (in dollars per share)	[1]	$ 0	$ 0	$ 0
Forfeited (in dollars per share)	[1]		0	0
Outstanding, end of period (in dollars per share)	[1]	0	0	0	$ 0
Exercisable (in dollars per share)	[1]	0
Maximum [Member]
Stock Options, Exercise Price per Share [Roll Forward]
Outstanding, beginning of period (in dollars per share)	[1]	0	0	0
Forfeited (in dollars per share)	[1]		0	0
Outstanding, end of period (in dollars per share)	[1]	0	$ 0	$ 0	$ 0
Exercisable (in dollars per share)	[1]	$ 0
[1]	Due to the May 2, 2018 1-for-500 reverse stock split, and no fractional shares being issued, all numbers are reduced to zero.

Stockholders' Equity - Assumpti

Stockholders' Equity - Assumptions Used to Determine Estimated Fair Value of Stock Options Granted (Detail) - $ / shares		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2015
Assumptions used to determine the fair value of stock options [Abstract]
Weighted average grant date fair value (in dollars per share)	[1]	$ 0
Stock Options [Member]
Assumptions used to determine the fair value of stock options [Abstract]
Weighted average risk-free interest rates (in hundredths)		2.15%	1.82%
Weighted average expected volatility (in hundredths)		170.42%	97.70%
Weighted average expected option term (in years)		7 years 3 months 14 days	5 years 1 month 24 days
Weighted average grant date fair value (in dollars per share)		$ 82.34	$ 4,964.73
[1]	Due to the May 2, 2018 1-for-500 reverse stock split, and no fractional shares being issued, all numbers are reduced to zero.

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Non-vested Options (Detail) - $ / shares		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Non-vested Options, Number of Options [Roll Forward]
Non-vested, beginning of period (in shares)	[1]	0	0
Granted (in shares)	[1]	0	0	0
Vested (in shares)	[1]	0	0
Forfeited (in shares)	[1]	0	0
Non-vested, end of period (in shares)	[1]	0	0	0
Non-vested Options, Weighted Average Exercise Price [Roll Forward]
Non-vested, beginning of period (in dollars per share)	[1]	$ 0	$ 0
Granted (in dollars per share)	[1]	0
Vested (in dollars per share)	[1]	0	0
Forfeited (in dollars per share)	[1]	0	0
Non-vested, end of period (in dollars per share)	[1]	$ 0	$ 0	$ 0
[1]	Due to the May 2, 2018 1-for-500 reverse stock split, and no fractional shares being issued, all numbers are reduced to zero.

Stockholders' Equity - Summar62

Stockholders' Equity - Summary of Restricted Stock Activity (Detail) - Restricted Stock [Member] - $ / shares		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Restricted Stock, Number of Shares [Roll Forward]
Outstanding, beginning of period (in shares)	[1]	0	0
Granted (in shares)	[1]	0	0
Vested (in shares)	[1]	0	0
Forfeited (in shares)	[1]	0	0
Outstanding, end of period (in shares)	[1]	0	0
Restricted Stock, Weighted Average Grant Date Fair Value [Roll Forward]
Non-vested, beginning of period (in dollars per share)	[1]	$ 0	$ 0
Granted (in dollars per share)	[1]	0	0
Vested (in dollars per share)	[1]	0	0
Forfeited (in dollars per share)	[1]	0	0
Non-vested, end of period (in dollars per share)	[1]	$ 0	$ 0
[1]	Due to the May 2, 2018 1-for-500 reverse stock split, and no fractional shares being issued, all numbers are reduced to zero.

Stockholders' Equity - Summar63

Stockholders' Equity - Summary of Warrant Activity (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Warrants outstanding [Roll Forward]
Outstanding, beginning of period (in shares)	78	44	9
Issued (in shares)	14,256	30	35
Exercised (in shares)	(246)	(3)
Expired (in shares)	(39)	(3)
Outstanding, end of period (in shares)	14,049	78	44	9
Warrants, Weighted Average Exercise Price [Roll Forward]
Outstanding, beginning of period (in dollars per share)	$ 910,000	$ 44,858,633	$ 15,170,879
Issued (in dollars per share)	2,299	840,000	2,240,000
Exercised (in dollars per share)	4,221	481,250	2,296,000
Expired (in dollars per share)	845,250	994,000	2,296,000
Outstanding, end of period (in dollars per share)	$ 1,569	$ 910,000	$ 44,858,633	$ 15,170,879
Weighted average remaining life	4 years 10 months 17 days	5 years 7 months 2 days	2 years 1 month 28 days	2 years 9 months 11 days
Minimum [Member]
Warrants, Exercise Price per Share [Roll Forward]
Outstanding, (in dollars per share)	$ 1,225	$ 281,750	$ 2,072,000	$ 4,900,000
Maximum [Member]
Warrants, Exercise Price per Share [Roll Forward]
Outstanding, (in dollars per share)	$ 19,712,000	$ 19,712,000	$ 19,712,000	$ 19,712,000

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)Input	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Nov. 30, 2017USD ($)	Nov. 30, 2016USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Number of inputs used for valuation of warrants | Input					6
Derivative warrant liability [Abstract]
Change in fair value of the warrant liability, net	$ 2,513	$ (38)	$ 17,209	$ 1,200	$ 15,103	$ 12,780	$ 564
Derivative warrant liabilities	6,883		6,883		$ 560	$ 18,751
Derivative warrant liabilities	$ 4,900		$ 4,900
November 2017 Warrants [Member] | Exchange Agreement [Member]
Derivative warrant liability [Abstract]
Value of warrants issued								$ 14,400	$ 14,400

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Fair Value of Warrants (Detail)	Jun. 30, 2018	Dec. 31, 2017
'Expected Volatility [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	1.9410
Risk-free Interest Rates [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	0.0278
Expected Life [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants term	5 years
Minimum [Member] | 'Expected Volatility [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	1.3269	1.3088
Minimum [Member] | Risk-free Interest Rates [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	0.0199	0.0168
Minimum [Member] | Expected Life [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants term	3 months 29 days	9 months 25 days
Maximum [Member] | 'Expected Volatility [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	3.7200	2.6692
Maximum [Member] | Risk-free Interest Rates [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	0.0292	0.0206
Maximum [Member] | Expected Life [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants term	6 years 4 months 24 days	4 years 10 months 17 days
November 2017 Warrants [Member] | 'Expected Volatility [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input		2.1739
November 2017 Warrants [Member] | Risk-free Interest Rates [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input		0.0198
November 2017 Warrants [Member] | Expected Life [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants term		4 years 10 months 17 days
October 2016 Warrants [Member] | 'Expected Volatility [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input		1.3088
October 2016 Warrants [Member] | Risk-free Interest Rates [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input		0.0206
October 2016 Warrants [Member] | Expected Life [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants term		3 years 9 months 3 days
July 2015 Series A Warrants [Member] | 'Expected Volatility [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input		1.6187
July 2015 Series A Warrants [Member] | Risk-free Interest Rates [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input		0.0194
July 2015 Series A Warrants [Member] | Expected Life [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants term		2 years 6 months 21 days
February 2015 Warrants [Member] | 'Expected Volatility [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input		1.6995
February 2015 Warrants [Member] | Risk-free Interest Rates [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input		0.0190
February 2015 Warrants [Member] | Expected Life [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants term		2 years 1 month 16 days
October 2013 Warrants [Member] | 'Expected Volatility [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input		2.6692
October 2013 Warrants [Member] | Risk-free Interest Rates [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input		0.0168
October 2013 Warrants [Member] | Expected Life [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants term		9 months 25 days

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Derivative Instruments Liabilities [Member] - Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Liabilities [Abstract]
Total Liabilities	$ 6,883	$ 560	$ 18,751
Level 3 [Member]
Liabilities [Abstract]
Total Liabilities	$ 6,883	$ 560	$ 18,751

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Measurements Using Significant Unobservable Inputs (Detail) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value Measurements Using Significant Unobservable Inputs (Level 3) [Roll Forward]
Beginning balance	$ 560	$ 18,751	$ 18,751	$ 3,785	$ 225
Fair value of warrants issued	23,532	0	16,953	28,472	4,247
Fair value of warrants exercised	0	$ (19,000)	(2,552)	(726)	(123)
Total change in the liability included in earnings	(17,209)		(15,103)	(12,780)	(564)
Extinguishment of convertible note warrant			(17,489)
Ending balance	$ 6,883		$ 560	$ 18,751	$ 3,785

Commitments - Additional Inform

Commitments - Additional Information (Detail)	1 Months Ended		12 Months Ended
	Oct. 31, 2016USD ($)ft²	Mar. 31, 2016USD ($)ft²	Dec. 31, 2017USD ($)ft²	Dec. 31, 2017EUR (€)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Operating Leased Assets [Line Items]
Rent expense			$ 600,000		$ 500,000	$ 400,000
Office Space At 1633 Broadway, New York, NY [Member]
Operating Leased Assets [Line Items]
Square footage of office space (in square feet) | ft²		6,877
Annual base rent		$ 522,652
Letter of credit [Abstract]
Minimum letter of credit amount required to be maintained under lease agreement					$ 130,663
Expiration date of letter of credit			Mar. 31, 2019	Mar. 31, 2019
Office Space at 810 Seventh Avenue, New York, NY [Member]
Operating Leased Assets [Line Items]
Square footage of office space (in square feet) | ft²			8,629
Expansion option, additional square footage of office space (in square feet) | ft²			8,629
Letter of credit [Abstract]
Minimum letter of credit amount required to be maintained under lease agreement			$ 881,297
Expiration date of letter of credit			Feb. 28, 2019	Feb. 28, 2019
Office Space in New York, NY, Lease Amendment [Member]
Operating Leased Assets [Line Items]
Additional square footage of office space leased under exercise of option right (in square feet) | ft²			8,629
Lease expiration date			Mar. 31, 2021	Mar. 31, 2021
Office Space in New York, NY, Initial Lease and Lease Amendment [Member] | Year 4 [Member]
Operating Leased Assets [Line Items]
Annual base rent			$ 996,000
Office Space in New York, NY, Initial Lease and Lease Amendment [Member] | Year 5 [Member]
Operating Leased Assets [Line Items]
Annual base rent			1,000,000
Office Space in New York, NY, Initial Lease and Lease Amendment [Member] | Years Thereafter [Member]
Operating Leased Assets [Line Items]
Annual base rent			$ 1,100,000
Park Road Lease Agreement [Member]
Operating Leased Assets [Line Items]
Square footage of office space (in square feet) | ft²	6,000
Annual base rent	$ 48,223
Operating lease term			2 years	2 years
Lease expiration period			2018-10	2018-10
Delcath's European Headquarters Lease Agreement [Member]
Operating Leased Assets [Line Items]
Square footage of office space (in square feet) | ft²			19,200
Annual base rent			$ 143,726	€ 183,179
Operating lease term			10 years	10 years

Commitments - Schedule Future M

Commitments - Schedule Future Minimum Lease Payments, Net of Receipts Due Under Terms of Subleases Under All Operating Leases (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Future minimum lease payments under all operating leases [Abstract]
2,018	$ 872
2,019	501
2,020	456
2,021	281
2,022	0
Total future minimum payments due	$ 2,110

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	6 Months Ended	12 Months Ended
	Sep. 30, 2015	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Income tax provision				$ 0	$ 0	$ 0
Percentage of valuation allowance against deferred tax assets				100.00%
Decrease in deferred tax assets valuation allowance				$ 1,100,000	76,600,000
Reduction in corporate income tax rate		21.00%		34.00%
Provisional income tax due to reduction in deferred tax assets				$ 143,500,000
Tax Cuts and Jobs Act, accounting complete		false
Scenario, Plan [Member]
Operating Loss Carryforwards [Line Items]
Reduction in corporate income tax rate			21.00%
Earliest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Open tax period				Dec. 31, 1998
Latest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Open tax period				Dec. 31, 2017
Federal [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards				$ 211,300,000	209,300,000	184,500,000
Operating loss carryforwards, amount subject to limitations				210,500,000
Operating loss carryforwards, annual limitation				27,500
Operating loss carryforwards net, expected to expire unutilized and unavailable to offset future federal taxable income				209,500,000
Federal [Member] | Expire Between 2018 And 2037 [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards				1,000,000
Federal [Member] | Tax Year 2013 [Member]
Operating Loss Carryforwards [Line Items]
Open tax period	Dec. 31, 2013
State and City [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards				$ 800,000	800,000
Operating loss carryforwards, expiration dates				2,037
Foreign [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards				$ 25,000,000	21,100,000	22,100,000
Federal and State [Member] | Earliest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Open tax period				Dec. 31, 2014
Federal and State [Member] | Latest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Open tax period				Dec. 31, 2017
Minimum [Member] | Federal [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, expiration dates				2,018
Minimum [Member] | State and City [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards				$ 27,300,000	27,300,000
Maximum [Member]
Operating Loss Carryforwards [Line Items]
Reduction in corporate income tax rate				35.00%
Maximum [Member] | Federal [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, expiration dates				2,037
Maximum [Member] | State and City [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards				$ 150,300,000	153,000,000
ASU 2016-16 [Member]
Operating Loss Carryforwards [Line Items]
Decrease in deferred tax assets valuation allowance		$ 834,000
Decrease in net operating loss deferred tax assets		$ 834,000
New York State [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards net, expected to expire unutilized and unavailable to offset future federal taxable income				149,000,000
New York City [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards net, expected to expire unutilized and unavailable to offset future federal taxable income				133,300,000
Research and Development Tax Credit Carryforwards [Member] | Federal [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards				$ 4,300,000	$ 4,000,000	$ 3,800,000
Tax credit carryforwards, expiration dates tag				2,037

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Before Income Taxes ( (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments [Abstract]
Domestic	$ (41,313)	$ (13,930)	$ (11,276)
Foreign	(3,804)	(4,040)	(3,428)
Income (loss) before taxes	$ (45,117)	$ (17,970)	$ (14,704)

Income Taxes - Income tax recon

Income Taxes - Income tax reconciliation (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Provision for income taxes [Abstract]
Income taxes using U.S federal statutory rate	$ (15,340,000)	$ (6,110,000)	$ (4,999,000)
Tax Cuts and Jobs Act	143,000
Nondeductible interest	6,912,000
Loss on extinguishment of debt	10,174,000
Loss of tax benefit of federal net operating loss carryforwards	5,067,000	68,795,000
Loss of tax benefit of state net operating loss carryforwards	1,373,000	13,891,000
Loss of tax benefit of federal tax credit carryforwards	324,000	4,023,000
Amortization of gain on IP migration	767,000	767,000	767,000
State income taxes, net of federal benefit	(1,339,000)	(2,576,000)	380,000
Foreign rate differential	1,196,000	1,141,000	920,000
Valuation allowance	(1,423,000)	(75,407,000)	2,649,000
Derivative charge	(8,403,000)	(4,345,000)	(192,000)
Stock option exercises and cancellations	841,000	53,000	674,000
Research and development costs	(295,000)	(250,000)	(199,000)
Other	3,000	18,000
Total	$ 0	$ 0	$ 0

Income Taxes - Significant Comp

Income Taxes - Significant Components of Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Employee compensation accruals	$ 292	$ 1,386	$ 1,279
Accrued liabilities	353	343	633
Research tax credits	17	22	3,796
Other	34	55	66
Net operating losses	5,289	6,194	77,906
Total deferred tax assets	5,985	8,000	83,680
Deferred tax liabilities:
Beneficial conversion feature		906
Other	13
Total deferred tax liabilities	13	906	0
Valuation allowance	5,972	7,094	83,680
Net deferred tax assets	$ 0	$ 0	$ 0

Income Taxes - Summary of Chang

Income Taxes - Summary of Change in Valuation Allowance (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Beginning balance	$ 7,094	$ 83,680
Charged to costs and expenses	(1,423)	(75,407)	$ 2,649
Charged to additional paid-in capital		(1,854)
Charged to retained earnings		1,010
Charged to other comprehensive income	301	(335)
Ending balance	$ 5,972	$ 7,094	$ 83,680

Quarterly Financial Data (Una75

Quarterly Financial Data (Unaudited) (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended											6 Months Ended				12 Months Ended
	Jun. 30, 2018		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017		Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2018		Jun. 30, 2017		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 858		$ 704	$ 684	$ 584		$ 743	$ 676	$ 435	$ 511	$ 370	$ 1,560		$ 1,327		$ 2,715	$ 1,992	$ 1,747
Costs and expenses	6,730		5,254	5,139	5,050		4,736	4,882	5,047	4,232	3,721	14,788		9,787		20,179	17,882	16,495
Operating loss	(6,092)		(4,725)	(4,627)	(4,601)		(4,212)	(4,383)	(4,724)	(3,871)	(3,462)	(13,595)		(8,814)		(18,165)	(16,440)	(15,210)
Net loss	$ (6,658)		$ (19,246)	$ (12,596)	$ (1,943)		$ (11,332)	$ (8,486)	$ (1,004)	$ (6,667)	$ (1,813)	$ 527		$ (13,276)		$ (45,117)	$ (17,971)	$ (14,704)
Basic loss per share	$ (7.26)	[1]	$ 375	$ 4,680	$ (1,373)	[1]	$ 43,750	$ 646,010	$ 115,495	$ 771,750	$ 218,750	$ 0.67	[1]	$ (15,656)	[1]
Previously Reported [Member]
Quarterly Financial Information Disclosure [Abstract]
Basic loss per share					$ 1,750
[1]	reflects a one-for-three hundred and fifty (1:350) reverse stock split effected on November 6, 2017 and a one-for-five hundred (1:500) reverse stock split effected on May 2, 2018.

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail)

Aug. 03, 2018USD ($)shares

Jul. 27, 2018USD ($)

Jul. 20, 2018USD ($)

May 02, 2018$ / sharesshares

Feb. 26, 2018shares

Feb. 09, 2018USD ($)$ / sharesshares

Nov. 06, 2017$ / sharesshares

Jul. 21, 2016$ / sharesshares

Jul. 19, 2016shares

Jun. 30, 2018$ / sharesshares

Dec. 31, 2017$ / sharesshares

Jan. 25, 2018shares

Dec. 31, 2016$ / sharesshares

Dec. 31, 2015$ / shares

Dec. 31, 2014$ / shares

Subsequent Event [Line Items]

Number of pre-funded warrants

76,000

Common stock, shares issued (in shares)

932,159

263,305

24

Common stock, shares outstanding (in shares)

932,158

263,304

23

Common stock, shares authorized (in shares)

170,000,000

1,000,000,000

1,000,000,000

500,000,000

Reverse stock split ratio

0.0020

0.0029

0.0625

Reverse stock split

1:500

1:350

Common stock, par value (in dollars per share) | $ / shares

$ 0.01

$ 0.01

$ 0.01

$ 0.01

Number of fractional shares were issued in connected with the reverse stock split

0

Minimum [Member]

Subsequent Event [Line Items]

Warrants exercisable per share price (in dollars per share) | $ / shares

1,225

281,750

$ 2,072,000

$ 4,900,000

Reverse stock split ratio

0.1

Maximum [Member]

Subsequent Event [Line Items]

Warrants exercisable per share price (in dollars per share) | $ / shares

$ 19,712,000

$ 19,712,000

$ 19,712,000

$ 19,712,000

Reverse stock split ratio

0.05

Board of Directors [Member]

Subsequent Event [Line Items]

Common stock, shares authorized (in shares)

1,000,000,000

Reverse stock split ratio

0.0020

Reverse stock split

1-for-500

Common stock, par value (in dollars per share) | $ / shares

$ 0.01

Board of Directors [Member] | Minimum [Member]

Subsequent Event [Line Items]

Common stock, shares authorized (in shares)

500,000,000

Reverse stock split ratio

0.01

Board of Directors [Member] | Maximum [Member]

Subsequent Event [Line Items]

Common stock, shares authorized (in shares)

1,000,000,000

Reverse stock split ratio

0.0020

OTCQB [Member]

Subsequent Event [Line Items]

Reverse stock split ratio

0.0020

0.0029

Reverse stock split

1:500

Common stock, par value (in dollars per share) | $ / shares

$ 0.01

$ 0.01

Number of fractional shares were issued in connected with the reverse stock split

0

0

Common Stock Issued [Member]

Subsequent Event [Line Items]

Number of fractional shares were issued in connected with the reverse stock split

93

Subsequent Event [Member]

Subsequent Event [Line Items]

Reverse stock split ratio

0.002

Reverse stock split

1:500

Subsequent Event [Member] | Registered Offering [Member]

Subsequent Event [Line Items]

Number of registered common stock offering

212,000,000

Number of pre-funded warrants

38,000,000

Number of pre-funded warrants to purchase shares of common stock

38,000,000

Gross proceeds from sale of warrants | $

$ 5,000,000

Offering price | $ / shares

$ 0.02

Number of common stock purchase warrant

1

Number of shares to purchase upon common stock purchase warrant

2

Purchase of common stock warrants, pre-funded warrants shall be paid at offering, per unit | $ / shares

$ 0.019

Purchase of common stock warrants, pre-funded warrants shall be paid upon exercise, per unit | $ / shares

$ 0.001

Warrants expiration period

5 years

Warrants exercisable per share price (in dollars per share) | $ / shares

$ 0.02

Common stock, shares issued (in shares)

434,981,824

Common stock, shares outstanding (in shares)

434,981,824

Subsequent Event [Member] | Rights Offering [Member]

Subsequent Event [Line Items]

Shares of non-transferrable subscription rights

500

Number of stock subscription rights

1

Subscriptions proceeds | $

$ 50,000,000

Subsequent Event [Member] | Exchange Agreement [Member]

Subsequent Event [Line Items]

Shares issuable upon warrants exercised

108,900,000

Subsequent Event [Member] | Securities Purchase Agreement [Member]

Subsequent Event [Line Items]

Gross proceeds from issuance of notes and warrants | $

$ 1,600,000

Subsequent Event [Member] | Minimum [Member] | Securities Purchase Agreement [Member] | Hudson Bay [Member]

Subsequent Event [Line Items]

Claims for monetary damages | $

$ 1,000,000

Subsequent Event [Member] | Maximum [Member] | Rights Offering [Member]

Subsequent Event [Line Items]

Purchase aggregate of common stock

28,571,429

Subsequent Event [Member] | OTCQB [Member]

Subsequent Event [Line Items]

Reverse stock split ratio

0.0020

Reverse stock split

1:500

Common stock, par value (in dollars per share) | $ / shares

$ 0.01

Number of fractional shares were issued in connected with the reverse stock split

0

Subsequent Event [Member] | Series D Warrants [Member] | Registered Offering [Member]

Subsequent Event [Line Items]

Number of warrants to purchase aggregate shares of common stock

500,000,000

Subsequent Event [Member] | Common Stock Issued [Member] | Registered Offering [Member]

Subsequent Event [Line Items]

Offering share issued

1

Subsequent Event [Member] | Warrants [Member] | Registered Offering [Member]

Subsequent Event [Line Items]

Offering share issued

1

Secured Convertible Notes Pay77

Secured Convertible Notes Payable and Common Stock Purchase Warrants - Schedule of Inputs Used to Value the Series D Warrants (Detail)	Jun. 30, 2018	Dec. 31, 2017
Expected Life [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected life (in years)	5 years
Expected Life [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected life (in years)	3 months 29 days	9 months 25 days
Expected Life [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected life (in years)	6 years 4 months 24 days	4 years 10 months 17 days
'Expected Volatility [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	1.9410
'Expected Volatility [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	1.3269	1.3088
'Expected Volatility [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	3.7200	2.6692
Risk-free Interest Rates [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	0.0278
Risk-free Interest Rates [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	0.0199	0.0168
Risk-free Interest Rates [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	0.0292	0.0206
Series D-1 Warrants [Member] | Expected Life [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected life (in years)	5 years 6 months
Series D-1 Warrants [Member] | 'Expected Volatility [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	2.1500
Series D-1 Warrants [Member] | Risk-free Interest Rates [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	0.0213
Series D-2 [101-113] Warrants [Member] | Expected Life [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected life (in years)	6 years 6 months
Series D-2 [101-113] Warrants [Member] | 'Expected Volatility [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	3.8900
Series D-2 [101-113] Warrants [Member] | Risk-free Interest Rates [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrants measurement input	0.0230