Seelos Therapeutics (SEELQ) 10-Q 21 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	May 16, 2019
Document And Entity Information [Abstract]
Entity Registrant Name	Seelos Therapeutics, Inc.
Trading Symbol	SEEL
Entity Central Index Key	0001017491
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Is Entity's Reporting Status Current?	Yes
Entity Common Stock, Shares Outstanding		21,277,229

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets
Cash	$ 11,292	$ 42
Due from related party	2	2
Deferred offering costs	0	140
Prepaid expenses and other current assets	1,026	7
Total current assets	12,320	191
Other long term assets	24	0
Total assets	12,344	191
Current liabilities
Accounts payable	2,421	2,220
Accrued expenses	2,428	84
Accrued interest	0	151
Convertible notes payable, at fair value	0	2,442
Warrant liabilities	4,458	0
Total liabilities	9,307	4,897
Commitments and contingencies (note 9)
Stockholders' equity (deficit)
Preferred stock, $.001 par value, 10,000,000 shares authorized, no shares issued or outstanding as of March 31, 2019 and December 31, 2018	0	0
Common stock, $.001 par value, 120,000,000 shares authorized, 20,213,762 and 3,081,546 issued and outstanding as of March 31, 2019 and December 31, 2018, respectively	20	3
Additional paid-in-capital	43,335	97
Accumulated deficit	(40,318)	(4,806)
Total stockholders' equity (deficit)	3,037	(4,706)
Total liabilities and stockholders' equity	$ 12,344	$ 191

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
Stockholders' equity
Preferred stock, par value (in usd per share)	$ 0.001	$ 0.001
Preferred stock, authorized (in shares)	10,000,000	10,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	120,000,000	120,000,000
Common stock, issued (in shares)	20,213,762	3,081,546
Common stock, outstanding (in shares)	20,213,762	3,081,546

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating expense
Research and development	$ 9,020	$ 536
General and administrative	3,322	100
Total operating expense	12,342	636
Loss before other expense	(12,342)	(636)
Other income (expense)
Interest income	25	0
Interest expense	(16)	(19)
Loss on warrant issuance	(5,020)	0
Change in fair value of warrant liabilities	(18,050)	0
Change in fair value of convertible notes payable	(109)	(6)
Total other expense	(23,170)	(25)
Net loss	$ (35,512)	$ (661)
Total loss per share basic and diluted	$ (3.98)	$ (0.21)
Weighted average common shares outstanding for basic and diluted loss per share	8,931,139	3,081,546

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net loss	$ (35,512)	$ (661)
Adjustments to reconcile net loss to net cash used in operating activities from continuing operations:
Stock-based compensation expense	38	8
Research and development expensed - license acquired	3,000	0
Change in fair value of convertible notes payable	109	6
Change in fair value of warrant liability	18,050	0
Loss on warrant issuance	5,020	0
Changes in operating assets and liabilities from continuing operations:
Prepaid expenses and other current assets	(1,019)	0
Other assets	(24)	0
Accounts payable	201	393
Accrued expenses	2,045	(73)
Accrued interest	12	19
Deferred offering costs	140	0
Net cash used in operating activities	(7,940)	(308)
Cash flows from financing activities:
Proceeds from issuance of common stock and warrants in a private offering	16,520	65
Proceeds from exercise of warrants	2,670	0
Net cash provided by financing activities from continuing operations	19,190	65
Cash flows from discontinued operations:
Net increase (decrease) in cash	11,250	(243)
Cash, beginning of period	42	258
Cash, end of period	11,292	15
Supplemental disclosure of cash flow information:
Cash paid for interest	0	0
Cash paid for income taxes	0	0
Non-cash investing and financing activities:
Issuance of common stock for conversion of debt	2,715	0
Issuance of common stock for conversion of accrued interest	164	0
Effect of reverse merger	299	0
Reclass of warrant liabilities related to Series A warrants exercised for cash	3,656	0
Reclass of Series B warrants from warrant liability to stockholders' equity	$ 31,473	$ 0

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Changes in Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Total
Beginning balance (in shares) at Dec. 31, 2017	3,081,546
Beginning balance at Dec. 31, 2017	$ 3	$ 64	$ (1,332)	$ (1,265)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	0	8	0	8
Reclass of Series B warrants from warrant liability to stockholders' equity				0
Issuance of common stock for conversion of debt and accrued interest				0
Net loss	$ 0	0	(661)	(661)
Ending balance (in shares) at Mar. 31, 2018	3,081,546
Ending balance at Mar. 31, 2018	$ 3	72	(1,993)	(1,918)
Beginning balance (in shares) at Dec. 31, 2018	3,081,546
Beginning balance at Dec. 31, 2018	$ 3	97	(4,806)	(4,706)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	$ 0	38	0	38
Issuance of common stock and warrants in a private offering, net of $16.5 million warrant liability, shares	1,829,407
Issuance of common stock and warrants in a private offering, net of $16.5 million warrant liability	$ 2	$ 0	$ 0	$ 2
Effect of reverse merger, shares	947,218	0	0	0
Effect of reverse merger	$ 1	$ (300)	$ 0	$ (299)
Warrants exercised for cash, shares	13,190,525
Warrants exercised for cash	$ 13	2,657	0	2,670
Issuance of common stock for license acquired, shares	992,782
Issuance of common stock for license acquired	$ 1	2,999	0	3,000
Reclass of warrant liabilites related to Series A warrants exercised for cash, shares	0
Reclass of warrant liabilites related to Series A warrants exercised for cash	$ 0	3,656	0	3,656
Reclass of Series B warrants from warrant liability to stockholders' equity, shares	0
Reclass of Series B warrants from warrant liability to stockholders' equity	$ 0	31,473	0	31,473
Issuance of common stock for conversion of debt and accrued interest, shares	172,284
Issuance of common stock for conversion of debt and accrued interest	$ 0	2,715	0	2,715
Net loss	$ 0	0	(35,512)	(35,512)
Ending balance (in shares) at Mar. 31, 2019	20,213,762
Ending balance at Mar. 31, 2019	$ 20	$ 43,335	$ (40,318)	$ 3,037

1. Organization and Description

1. Organization and Description of Business	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Organization and description of business operations	1. Organization and Description of Business Seelos Therapeutics, Inc. and subsidiary (the "Company") plans on developing its clinical and regulatory strategy with its internal research and development team with a view toward prioritizing market introduction as quickly as possible. The Company's lead programs following the completion of the Merger (as defined below) are SLS-002 for the potential treatment of suicidality in post-traumatic stress disorder, and in major depressive disorder, SLS-005 for Sanfilippo syndrome and SLS-006 for the potential treatment of Parkinson's disease. Additionally, the Company is developing several preclinical programs, most of which have well-defined mechanisms of action, including: SLS-008 targeted at chronic inflammation in asthma and orphan indications such as pediatric esophagitis, SLS-010, in narcolepsy and related disorders and SLS-012, an injectable therapy for post-operative pain management. Merger with Apricus Biosciences, Inc. On January 24, 2019, the Company completed the acquisition of Apricus Biosciences, Inc., a Nevada corporation ("Apricus"), in accordance with the terms of the Agreement and Plan of Merger Reorganization (the "Merger Agreement") entered into on July 30, 2018. Pursuant to the Merger Agreement, (i) a subsidiary of Apricus merged with and into Seelos Therapeutics, Inc., a Delaware corporation ("Seelos"), with Seelos (renamed as "Seelos Corporation") continuing as a wholly owned subsidiary of Apricus and the surviving corporation of the merger and (ii) Apricus was renamed as Seelos Therapeutics, Inc." (the "Merger"). The Merger was accounted for as a reverse recapitalization under United States generally accepted accounting principles ("U.S. GAAP") because the primary assets of Apricus were nominal following the close of the Merger. Seelos was determined to be the accounting acquirer based upon the terms of the Merger and other factors including: (i) Seelos stockholders and other persons holding securities convertible, exercisable or exchangeable directly or indirectly for Seelos common stock owned the majority of Apricus immediately following the effective time of the Merger, (ii) Seelos holds the majority (four of five) of board seats of the combined company and (iii) Seelos' management holds all key positions in the management of the combined company. Accordingly, the historical financial statements of Seelos Therapeutics Inc. became the Company's historical financial statements including the comparative prior periods. All references in the unaudited condensed consolidated financial statements to the number of shares and per-share amounts of common stock have been retroactively restated to reflect the exchange rate. Liquidity The Company had no revenues, incurred operating losses since inception, and expects to continue to incur significant operating losses for the foreseeable future and may never become profitable. As of March 31, 2019, the Company had $11.3 million in cash and an accumulated deficit of $40.3 million. The Company has historically funded its operations through the issuance of convertible notes (see note 5), sale of common stock (see note 3) and warrants (see note 6). The Company has an effective shelf registration statement on Form S-3 filed with the SEC under which it may offer from time to time any combination of debt securities, common and preferred stock and warrants. As of March 31, 2019, the Company had approximately $95.2 million available under its Form S-3 shelf registration statement. Under current SEC regulations, in the event the aggregate market value of the Company's common stock held by non-affiliates ("public float"), is less than $75.0 million, the amount it can raise through primary public offerings of securities in any twelve-month period using shelf registration statements is limited to an aggregate of one-third of the Company's public float. SEC regulations permit the Company to use the highest closing sales price of the Company's common stock (or the average of the last bid and last ask prices of the Company's common stock) on any day within 60 days of sales under the shelf registration statement. As of March 31, 2019, the Company's public float was approximately $68.3 million based on 15.2 million shares of the Company's common stock outstanding at a price of $4.50 per share, which was the closing sale price of the Company's common stock on January 31, 2019. As the Company's public float was less than $75.0 million as of March 31, 2019, the Company's usage of its S-3 shelf registration statement is limited. The Company still maintains the ability to raise funds through other means, such as through the filing of a registration statement on Form S-1 or in private placements. The rules and regulations of the SEC or any other regulatory agencies may restrict the Company's ability to conduct certain types of financing activities, or may affect the timing of and amounts it can raise by undertaking such activities. The accompanying unaudited condensed consolidated financial statements have been prepared assuming the Company will continue to operate as a going concern, which contemplates the realization of assets and settlement of liabilities in the normal course of business, and do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classifications of liabilities that may result from uncertainty related to its ability to continue as a going concern. The Company's future liquidity and capital funding requirements will depend on numerous factors, including: its ability to raise additional funds to finance its operations; its ability to maintain compliance with the listing requirements of The Nasdaq Capital Market ("Nasdaq"); the outcome, costs and timing of clinical trial results for the Company's current or future product candidates; the extent and amount of any indemnification claims; litigation expenses and the extent and amount of any indemnification claims; the emergence and effect of competing or complementary products; its ability to maintain, expand and defend the scope of its intellectual property portfolio, including the amount and timing of any payments the Company may be required to make, or that it may receive, in connection with the licensing, filing, prosecution, defense and enforcement of any patents or other intellectual property rights; its ability to retain its current employees and the need and ability to hire additional management and scientific and medical personnel; the terms and timing of any collaborative, licensing or other arrangements that it has or may establish; the trading price of its common stock; and its ability to increase the number of authorized shares outstanding to facilitate future financing events. The Company will likely need to raise substantial additional funds through one or more of the following: issuance of additional debt or equity, or the completion of a licensing transaction for one or more of the Company's pipeline assets. If the Company is unable to maintain sufficient financial resources, its business, financial condition and results of operations will be materially and adversely affected. This could affect future development and business activities and potential future clinical studies and/or other future ventures. Failure to obtain additional equity or debt financing will have a material, adverse impact on the Company's business operations. There can be no assurance that the Company will be able to obtain the needed financing on acceptable terms or at all. Additionally, equity or debt financings will likely have a dilutive effect on the holdings of the Company's existing stockholders.

2. Significant Accounting Polic

2. Significant Accounting Policies	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Significant accounting policies	2. Significant accounting policies Basis of presentation The accompanying unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto as of and for the year ended December 31, 2018 included in the Company's Annual Report on Form 10-K ("Annual Report") filed with the U.S. Securities and Exchange Commission (the "SEC") on March 28, 2019. The accompanying financial statements have been prepared by the Company in accordance with U.S. GAAP for interim financial information and in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. In the opinion of management, the accompanying unaudited condensed consolidated financial statements for the periods presented reflect all adjustments, consisting of only normal, recurring adjustments, necessary to fairly state the Company's financial position, results of operations and cash flows. The December 31, 2018 condensed consolidated balance sheet was derived from audited financial statements, but does not include all U.S. GAAP disclosures. The unaudited condensed consolidated financial statements for the interim periods are not necessarily indicative of results for the full year. The preparation of these unaudited condensed consolidated financial statements requires the Company to make estimates and judgments that affect the amounts reported in the financial statements and the accompanying notes. The Company's actual results may differ from these estimates under different assumptions or conditions. Use of estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. The most significant estimates in the Company's financial statements relate to the valuation of warrants, valuation of convertible notes payable, valuation of common stock and the valuation of stock options. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of expenses that are not readily apparent from other sources. Actual results may differ materially and adversely from these estimates. To the extent there are material differences between the estimates and actual results, the Company's future results of operations will be affected. Fair Value Measurements The Company follows the accounting guidance in Accounting Standards Codification ("ASC") Topic 820, Fair Value Measurements and Disclosures ("ASC 820"), for its fair value measurements of financial assets and liabilities measured at fair value on a recurring basis. Under this accounting guidance, fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. The accounting guidance requires fair value measurements be classified and disclosed in one of the following three categories: Level 1: Quoted prices in active markets for identical assets or liabilities. Level 2: Observable inputs other than Level 1 prices, for similar assets or liabilities that are directly or indirectly observable in the marketplace. Level 3: Unobservable inputs which are supported by little or no market activity and that are financial instruments whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company's warrant liabilities and convertible notes were classified within Level 3 of the fair value hierarchy because their fair values were estimated by utilizing valuation models and significant unobservable inputs. The warrants and convertible notes were valued using a scenario-based discounted cash flow analysis. Two primary scenarios were considered and probability weighted to arrive at the valuation conclusion for each convertible note. The first scenario considers the value impact of conversion at the stated discount to the issue price in a qualified financing event, while the second scenario assumes the convertible notes are held to maturity. The following tables present information about the Company's financial assets and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values. There were no transfers between fair value measurement levels during the three months ended March 31, 2019: Fair Value Measurements as of March 31, 2019 (Level 1) (Level 2) (Level 3) Total Assets Cash $ 11,292 $ - $ - $ 11,292 Liabilities Warrant liabilities $ - $ - $ 4,458 $ 4,458 Fair Value Option As permitted under ASC Topic 825, Financial Instruments, ("ASC 825"), the Company had elected the fair value option to account for its convertible notes. In accordance with ASC 825, the Company records these convertible notes at fair value with changes in fair value recorded in the Statement of Operations. As a result of applying the fair value option, direct costs and fees related to the convertible notes were expensed as incurred and were not deferred. Stock-based compensation The Company expenses stock-based compensation to employees, non-employees and board members over the requisite service period based on the estimated grant-date fair value of the awards and forfeitures rates. The Company accounts for forfeitures as they occur. Stock-based awards with graded-vesting schedules are recognized on a straight-line basis over the requisite service period for each separately vesting portion of the award. The Company estimates the fair value of stock option grants using the Black-Scholes option pricing model, and the assumptions used in calculating the fair value of stock-based awards represent management's best estimates and involve inherent uncertainties and the application of management's judgment. All stock-based compensation costs are recorded in general and administrative or research and development costs in the statements of operations based upon the underlying individual's role at the Company. Net Loss Per Share Basic loss per share is computed by dividing net loss applicable to common stockholders by the weighted average number of shares of common stock outstanding during each period. Diluted loss per share includes the effect, if any, from the potential exercise or conversion of securities, such as convertible debt, warrants and stock options that would result in the issuance of incremental shares of common stock. In computing the basic and diluted net loss per share applicable to common stockholders, the weighted average number of shares remains the same for both calculations due to the fact that when a net loss exists, dilutive shares are not included in the calculation as the impact is anti-dilutive. The following potentially dilutive securities outstanding as of March 31, 2019 and 2018 have been excluded from the computation of diluted weighted average shares outstanding, as they would be anti-dilutive (in thousands): As of March 31, 2019 2018 Outstanding stock options 411 31 Outstanding warrants 2,488 - Convertible notes - 104 2,899 135 Amounts in the table reflect the common stock equivalents of the noted instruments. Recent Accounting Pronouncements In February 2016, the FASB issued Accounting Standards Update ("ASU") 2016-2, Leases. The new standard establishes a right-of-use ("ROU") model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. The new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. A modified retrospective transition approach is required for lessees for capital and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. The Company adopted ASU 2016-2 on January 1, 2019 and the adoption of the standard did not have a material effect on its unaudited condensed consolidated financial statements and related disclosures. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820), Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement ("ASU 2018-13"). The amendments in this ASU require certain existing disclosure requirements in Topic 820 to be modified or removed, and certain new disclosure requirements to be added to the Topic. In addition, this ASU allows entities to exercise more discretion when considering fair value measurement disclosures. ASU 2018-13 will be effective for the Company beginning January 1, 2020 with early adoption permitted. The Company is in the process of evaluating the impact of ASU 2018-13 on its consolidated financial statements and related disclosures.

3. Pre-merger Financing

3. Pre-merger Financing	3 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
Pre-merger Financing	3. Pre-merger Financing On January 24, 2019, Seelos Corporation and Apricus closed a private placement transaction with certain accredited investors (the "Investors"), whereby, among other things, Seelos Corporation issued to investors shares of the Company's common stock immediately prior to the Merger in a private placement transaction (the "Financing"), pursuant to the Securities Purchase Agreement, made and entered into as of October 16, 2018, by and among Seelos Corporation, Apricus and the investors, as amended (the "Purchase Agreement"). Pursuant to the Purchase Agreement, Seelos Corporation issued and sold to the Investors an aggregate of 2,374,672 shares of Seelos Corporation's common stock as converted pursuant to the exchange ratio in the Merger into the right to receive 1,829,407 shares of Common Stock and (ii) issued warrants representing the right to acquire 1,463,519 shares of Common Stock at a price per share of $4.15, subject to adjustment as provided therein (the "Series A Warrants"), and additional warrants representing the right the right to acquire 0 shares of Common Stock at a price per share of $0.001, subject to adjustment as provided therein (the "Series B Warrants" together with the Series A Warrants, the "Investor Warrants"), for aggregate gross proceeds of $18.0 million, or $16.5 million net of financing fees. The terms of the Investor Warrants included certain provisions that could result in adjustments to both the number of warrants issued and the exercise price of each warrant, which resulted in the warrants being classified as a liability upon issuance. See Note 7. The Investor Warrants were recorded at fair value of $21.5 million upon issuance and given the liability exceed the proceeds received, a loss of $5.0 million was recognized. On March 7, 2019, the Company entered into Amendment Agreements (collectively, the "Amendment Agreements") with each Investor amending: (i) the Purchase Agreement, (ii) the Series A Warrants and (iii) the Series B Warrants. The Amendment Agreements, among other things, (i) fixed the aggregate number of shares of Common Stock issued and issuable pursuant to the Series B Warrants at 11,614,483 (which number includes shares of Common Stock issued pursuant to exercises of Series B Warrants on or prior to March 7, 2019), (ii) fixed the aggregate number of shares of Common Stock issued and issuable pursuant to the Series A Warrants at 3,629,023 (none of which were exercised as of March 7, 2019), (iii) reduced the duration of the period during which the Investors were limited in the number of shares of Common Stock subject to Series B Warrants that Investors can exercise on a daily basis, such that such period terminated on March 21, 2019, (iv) reduced the duration of the period during which the number of shares of Common Stock underlying the Series B Warrants would adjust based on the volume-weighted average price of the Common Stock, such that the adjustment period terminated on March 7, 2019, (v) fixed the "Reset Price" based on which the Series B Warrants adjusted on March 7, 2019 at $1.3389, (vi) amended the Purchase Agreement such that the date until which the Company was restricted from effecting certain variable rate transactions would be March 20, 2019, (vii) amended the Series A Warrants so that any references therein to the Series B Warrants refer to the Series B Warrants, as amended or restated from time to time, and (viii) made certain other technical, conforming and clarifying changes. The terms of the Investor Warrants continue to include certain provisions that could result in a future adjustment to the exercise price of the Investor Warrants and accordingly, they continue to be classified as a liability after the Amendment Agreements. At March 31, 2019, 5,000 Series B Warrants and 2.0 million Series A Warrants remain unexercised, respectively.

4. Purchase of Assets

4. Purchase of Assets	3 Months Ended
	Mar. 31, 2019
In-Licensing Agreement [Abstract]
Purchase of Assets	4. Purchase of assets Acquisition of License from Ligand Pharmaceuticals Incorporated On September 21, 2016, the Company entered into a License Agreement (the "License Agreement") with Ligand Pharmaceuticals Incorporated ("Ligand"), Neurogen Corporation and CyDex Pharmaceuticals, Inc. (collectively, the "Licensors"), pursuant to which, among other things, the Licensors granted to the Company an exclusive, perpetual, irrevocable, worldwide, royalty-bearing, nontransferable right and license under (i) patents related to a product known as Aplindore, which is now known as SLS-006, acetaminophen (as it may have been or may be modified for use in a product to be administered by any method in any form including, without limitation injection and intravenously, the sole active pharmaceutical ingredient of which is acetaminophen), which is now known as SLS-012, an H3 receptor antagonist, which is now known as SLS-010, and either or both of the Licensors' two proprietary CRTh2 antagonists, which are now known collectively as SLS-008 (collectively, the "Licensed Products"), and (ii) copyrights, trade secrets, moral rights and all other intellectual and proprietary rights related thereto. The Company is obligated to use commercially reasonable efforts to (a) develop the Licensed Products, (b) obtain regulatory approval for the Licensed Products in the United States, the European Union (either in its entirety or including at least one of France, Germany or, if at the time the United Kingdom is a member of the European Union, the United Kingdom), the United Kingdom, if at the time the United Kingdom is not a member of the European Union, Japan or the People's Republic of China, each of which is referred to as a Major Market, and (c) commercialize the Licensed Products in each country where regulatory approval is obtained. The Company has the exclusive right and sole responsibility and decision-making authority to research and develop any Licensed Products and to conduct all clinical trials and non-clinical studies the Company believes appropriate to obtain regulatory approvals for commercialization of the Licensed Products. The Company also has the exclusive right and sole responsibility and decision-making authority to commercialize any of the Licensed Products. As consideration for the grant of the rights and licenses under the License Agreement, the Company paid to Ligand a nominal option fee. As further partial consideration for the grant of the rights and licenses to the Company under the License Agreement, the Company was obligated pay to Ligand an aggregate of $1.3 million within 30 days after the closing of the issuance and sale by the Company of debt and/or equity securities for gross proceeds to the Company of at least $7.5 million. In connection with the closing of the Merger, the Company issued 392,307 shares of common stock to settle this obligation. As further partial consideration for the grant of the rights and licenses to the Company by Ligand under the License Agreement, the Company agreed to pay to Ligand certain one-time, non-refundable milestone payments upon the achievement of certain financing milestones, consisting of (i) the lesser of $3.5 million or 10% of the net proceeds to the company in the event of the Company's initial public offering or a financing transaction consummated in connection with a transaction as a result of which the Company's business becomes owned or controlled by an existing issuer with a class of securities registered under the Securities Exchange Act of 1934, as amended, and immediately after such transaction, the security holders of the Company as of immediately before such transaction own, as a result of such transaction, at least 35% of the equity securities or voting power of such issuer, or (ii) the lesser of $3.5 million or 10% of the net proceeds to the Company in the event the Company is acquired. In connection with the closing of the Merger, the Company issued 408,946 shares of common stock to settle this obligation. The Company recognized research and development expense totaling approximately $2.2 million during the period ended March 31, 2019 for the common stock issued in connection with the Merger. As further consideration for the grant of the rights and licenses to under the License Agreement, the Company agreed to pay to Ligand certain one-time, non-refundable regulatory milestone payments in connection with the Licensed Products, other than in connection with Aplindore for the indication of Parkinson's disease or Restless Leg Syndrome, consisting of (i) $750,000 upon submission of an application with the FDA or equivalent foreign body for a particular Licensed Product, (ii) $3.0 million upon FDA approval of an application for a particular Licensed Product, (iii) $1.125 million upon regulatory approval in a Major Market for a particular Licensed Product, and (iv) $1.125 million upon regulatory approval in a second Major Market for a particular Licensed Product. As further consideration for the grant of the rights and licenses to under the License Agreement, the Company agreed to pay to Ligand certain one-time, non-refundable regulatory milestone payments in connection with the Licensed Products in connection with Aplindore for the indication of Parkinson's disease or Restless Leg Syndrome, consisting of (i) $100,000 upon submission of an application with the FDA or equivalent foreign body for such a particular Licensed Product, (ii) $350,000 upon FDA approval of an application for such a particular Licensed Product, (iii) $125,000 upon regulatory approval in a Major Market for such a particular Licensed Product, and (iv) $125,000 upon regulatory approval in a second Major Market for such a particular Licensed Product. As further partial consideration for the grant of the rights and licenses under the License Agreement, the Company agreed to pay to Ligand certain one-time, non-refundable commercial milestone payments in connection with the Licensed Products, consisting of (i) $10.0 million upon the achievement of $1.0 billion of cumulative worldwide net sales of Licensed Products based upon Aplindore, (ii) $10.0 million upon the achievement of $1.0 billion of cumulative worldwide net sales of Licensed Products based upon an H3 receptor antagonist, (iii) $10.0 million upon the achievement of $1.0 billion of cumulative worldwide net sales of Licensed Products based upon acetaminophen (as it may have been or may be modified for use in a product to be administered by any method in any form including, without limitation injection and intravenously, the sole active pharmaceutical ingredient of which is acetaminophen), (iv) $10.0 million upon the achievement of $1.0 billion of cumulative worldwide net sales of Licensed Products based upon CRTh2 antagonists, (v) $20.0 million upon the achievement of $2.0 billion of cumulative worldwide net sales of Licensed Products based upon Aplindore, (vi) $20.0 million upon the achievement of $2.0 billion of cumulative worldwide net sales of Licensed Products based upon an H3 receptor antagonist, (vii) $20.0 million upon the achievement of $2.0 billion of cumulative worldwide net sales of Licensed Products based upon acetaminophen (as it may have been or may be modified for use in a product to be administered by any method in any form including, without limitation injection and intravenously, the sole active pharmaceutical ingredient of which is acetaminophen), and (viii) $20.0 million upon the achievement of $2.0 billion of cumulative worldwide net sales of Licensed Products based upon CRTh2 antagonists. The Company will also pay to Ligand middle single-digit royalties on aggregate annual net sales of Licensed Products other than in connection with Aplindore for the indication of Parkinson's disease or Restless Leg Syndrome in a country where such Licensed Products are covered under a licensed patent and a tiered incremental royalty in the upper single digit to lower double digit range on aggregate annual net sales of Licensed Products in connection with Aplindore for the indication of Parkinson's disease or Restless Leg Syndrome in a country where such Licensed Products are covered under a licensed patent. Additionally, the Company will pay to Ligand low single digit royalties on aggregate annual net sales of Licensed Products other than in connection with Aplindore for the indication of Parkinson's disease or Restless Leg Syndrome in a country where such Licensed Products are not covered under a licensed patent and a tiered incremental royalty in the lower single digit to middle single digit range on aggregate annual net sales of Licensed Products in connection with Aplindore for the indication of Parkinson's disease or Restless Leg Syndrome in a country where such Licensed Products are not covered under a licensed patent. The potential regulatory and commercial milestones are not yet considered probable, and no milestone payments have been accrued at March 31, 2019. Acquisition of Assets from Vyera Pharmaceuticals, AG ("Vyera") On May 25, 2017, the Company entered into a non-binding term sheet to acquire TUR-002 (intranasal ketamine) ("TUR-002") from Vyera. During the year ended December 31, 2017, the Company recorded $400,000 in research and development expenses related to the non-refundable but creditable payments to continue to negotiate exclusively with Vyera while the Company continued to identify financing terms with other parties to provide the necessary funding to purchase TUR-002. On January 18, 2018, the Company and Vyera entered into an Amendment to the May 25, 2017 Term Sheet for TUR-002. The Company paid $100,000 as a non-refundable but creditable payment to continue to negotiate exclusively with Vyera to purchase TUR-002. On March 6, 2018, the Company entered into an Asset Purchase Agreement with Vyera, as amended by an amendment thereto entered into on May 18, 2018 (the "First Vyera Amendment") and an amendment thereto entered into on December 31, 2018 (the "Second Vyera Amendment" such agreement, as amended by the First Vyera Amendment and the Second Vyera Amendment, the "Vyera Asset Purchase Agreement"). Pursuant to the Vyera Asset Purchase Agreement, the Company agreed to acquire the assets (the "Vyera Assets"), and liabilities (the "Vyera Assumed Liabilities"), of Vyera related to a product candidate known as TUR-002 (intranasal ketamine), which is now known as SLS-002. The Company is obligated to use commercially reasonable efforts to seek regulatory approval in the United States for and commercialize SLS-002. The Company agreed that if it receives regulatory approval to commence a Phase III clinical trial for SLS-002 and no third party has alleged any claim of conflict, infringement, invalidity or other violation of any rights of others with regard to the Vyera Assets, then the Company must commence a Phase III clinical trial for SLS-002 by the date 18 months from the closing of the transactions contemplated by the Vyera Asset Purchase Agreement (the "Vyera Closing"), and if the Company fails to do so, the Vyera Asset Purchase Agreement will terminate immediately and become null and void and all of the Vyera Assets and the Vyera Assumed Liabilities will automatically be returned to Vyera. In the event that, prior to the fourth anniversary of the Vyera Closing, the Company sells, directly or indirectly, all or substantially all of the Vyera Assets to a third party, then the Company must pay Vyera an amount equal to 4% of the net proceeds actually received by the Company as an upfront payment in such sale. As partial consideration for the Vyera Assets, upon execution of the First Vyera Amendment, the Company paid to Vyera a non-refundable cash payment of $150,000. As further partial consideration for the Vyera Assets, upon public announcement of the entry by the Company and the Company into the Merger Agreement, the Company paid to Vyera a non-refundable cash payment of $150,000. As further partial consideration for the Vyera Assets the Company issued Vyera 191,529 shares of Common Stock and paid Vyera a non-refundable cash payment of $1,000,000. As further partial consideration for the Vyera Assets, the Company agreed to pay to Vyera certain one-time, non-refundable milestone payments consisting of (i) $3.5 million upon dosing of the first patient in a Phase III clinical trial for SLS-002, (ii) $10.0 million upon approval by the U.S. Food and Drug Administration (the "FDA") of a new drug application ("NDA"), with respect to SLS-002, (iii) $5.0 million upon approval by the European Medicines Agency (the "EMA") of the foreign equivalent to an NDA with respect to SLS-002 in a Major Market, (iv) $2.5 million upon approval by the EMA of the foreign equivalent to an NDA with respect to SLS-002 in a second Major Market, (v) $5.0 million upon the achievement of $250.0 million in net sales of SLS-002, (vi) $10.0 million upon the achievement of $500.0 million in net sales of SLS-002, (vii) $15.0 million upon the achievement of $1.0 billion in net sales of SLS-002, (viii) $20.0 million upon the achievement of $1.5 billion in net sales of SLS-002 and (ix) $25.0 million upon the achievement of $2.0 billion in net sales of SLS-002. The Company will also pay to Vyera royalty percentage in the mid-teens on aggregate annual net sales of SLS-002. Acquisition of Assets from Bioblast Pharma Ltd. ("Bioblast") On February 15, 2019, the Company entered into an Asset Purchase Agreement (the "Bioblast Asset Purchase Agreement") with Bioblast. Pursuant to the Bioblast Asset Purchase Agreement, the Company acquired all of the assets of Bioblast relating to a therapeutic platform known as Trehalose (the "Bioblast Asset Purchase"). At the closing of the Bioblast Asset Purchase (the "Bioblast Closing"), the Company paid to Bioblast $1.5 million in cash, and the Company agreed to pay to Bioblast an additional $2.0 million in cash by the one-year anniversary of the Bioblast Closing. Accordingly, the Company recognized $3.5 million charge to research and development expense during the period ended March 31, 2019. Under the terms of the Bioblast Asset Purchase Agreement, the Company agreed to pay additional consideration to Bioblast upon the achievement of certain milestones in the future, as follows: (i) within 15 days following the completion of the Company's or the Company's affiliate's first Phase 2(b) clinical trial of Trehalose satisfying certain criteria, the Company will pay to Bioblast $8.5 million in cash; and (ii) within 15 days following the approval for commercialization by the FDA or the Health Products and Food Branch of Health Canada of the first NDA or New Drug Submission, respectively, of Trehalose filed by the Company or its affiliates, the Company will pay to Bioblast $8.5 million in cash. In addition, the Company agreed to pay Bioblast a cash royalty equal to 1% of the net sales of Trehalose. Under the terms of the Bioblast Asset Purchase, the Company assumed a collaborative agreement with Team Sanfilippo Foundation ("TSF"), a nonprofit medical research foundation founded by parents of children with Sanfilippo syndrome. TSF, upon approval by the FDA, plans to begin an open label, Phase 2(b) clinical trial in up to 20 patients with Sanfilippo syndrome, which is now known under the study name SLS-005. The Company will provide the clinical supply of Trehalose. The terms of the Bioblast Asset Purchase Agreement entitle the Company access to all clinical data from this trial.

5. Acquisition of Apricus

5. Acquisition of Apricus	3 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
5. Acquisition of Apricus	5. Acquisition of Apricus On January 24, 2019, the Company completed the acquisition of Apricus in accordance with the terms of the Merger Agreement. The Merger was accounted for as a reverse recapitalization under U.S. GAAP because the primary assets of Apricus were nominal at the close of the Merger. Seelos was determined to be the accounting acquirer based upon the terms of the Merger and other factors including: (i) Seelos stockholders and other persons holding securities convertible, exercisable or exchangeable directly or indirectly for Seelos common stock owned the majority of the Company immediately following the effective time of the Merger, (ii) Seelos holds the majority (four of five) of board seats of the combined company and (iii) Seelos' management holds all key positions in the management of the combined company. Upon the completion of the Merger, Seelos acquired no tangible assets and assumed no employees or operation from Apricus. Additionally, Apricus' intellectual property was considered to have no value. The remaining Apricus liabilities had a fair value of approximately $300 thousand. In connection with the Merger, Seelos entered into a Contingent Value Rights Agreement (the "CVR Agreement"). Pursuant to the CVR Agreement, Apricus stockholders received one CVR for each share of Apricus common stock held of record immediately prior to the closing of the merger. Each CVR represents the right to receive payments based on Apricus' Vitaros assets. In particular, CVR holders will be entitled to receive 90% of any cash payments (or the fair market value of any non-cash payments) exceeding $500,000 received, during a period of ten years from the closing of the merger, based on the sale or out-licensing of Apricus' Vitaros intangible asset, including any milestone payments (the "Contingent Payments"), less reasonable transaction expenses. After the completion of the merger, Seelos will be entitled to retain the first $500,000 and 10% of any Contingent Payments. Seelos assigned no value to the Vitaros intangible asset or the CVR in the acquisition accounting.

6. Convertible Notes

6. Convertible Notes	3 Months Ended
	Mar. 31, 2019
Warrants Expiring March 2023, Tranche 2 [Member]
Convertible Notes	6. Convertible Notes From May 2017 to October 2018, the Company entered into convertible note agreements with investors. The aggregate principal amount of the Notes was $2.3 million which were due no later than April 30, 2019 with simple interest at the rate of 8% per annum. The Notes automatically converted, upon the issuance of preferred stock of the Company for capital-raising purposes occurring on or prior to the Notes' maturity date resulting in gross proceeds in excess of a specific amount, into shares of common stock of the Company by dividing the then-outstanding balance of each convertible note by 80% or 90%, depending on the terms for each note, of the lowest purchase price per share paid, or $9.70 to $10.91 per share, respectively, by another investor in the qualifying financing, which condition was satisfied by the Pre-Merger Financing. The Notes are carried at fair value. The Company recognized an adjustment to for changes in the Notes fair value of $0.1 million and $6 thousand during the periods ended March 31, 2019 and 2018, respectively. In connection with the closing of the Merger, the Notes plus unpaid interest were converted into 172,295 shares of Common Stock at a price of $9.70 or $10.91 per share.

7. Stockholders' Equity

7. Stockholders' Equity	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Stockholders' Equity	7. Stockholders' Equity Preferred Stock The Company is authorized to issue 10.0 million shares of preferred stock, par value $0.001. No shares of preferred stock were outstanding as of March 31, 2019 or December 31, 2018. Common Stock The Company has authorized 120,000,000 shares of Common Stock as of March 31, 2019 and had authorized 60,000,000 shares of Common Stock, as of December 31, 2018. Each share of common stock is entitled to one voting right. Common stock owners are entitled to dividends when funds are legally available and declared by the Board of Directors. Warrants Series A Warrants The Series A Warrants were initially exercisable for 1,463,519 shares of Common Stock at an exercise price per share equal to $4.15, which was adjusted to 2,640,128 shares of the Common Stock at an exercise price per share equal to $2.3005 on February 27, 2019 and which was further adjusted to 3,629,023 shares of Common Stock at an exercise price per share equal to $1.6736 on March 7, 2019, in each case, pursuant to the terms thereof. The Series A Warrants were immediately exercisable upon issuance and have a term of five years from the date of issuance. During the three months ended March 31, 2019, 1.6 million Series A Warrants were exercised for approximately $2.6 million. As of March 31, 2019, 2.0 million Series A Warrants remain outstanding at an exercise price of $1.6736 per share. Series B Warrants The Series B Warrants were initially exercisable for no shares of Common Stock, which was adjusted to 7,951,090 shares of Common Stock on February 27, 2019 and which was further adjusted to 11,614,483 shares of Common Stock on March 7, 2019, in each case, pursuant to the terms thereof. The Series B Warrants have an exercise price of $0.001, were immediately exercisable upon issuance and will expire on the day following the later to occur of (i) the Reservation Date, and (ii) the date on which the Series B Warrants have been exercised in full (without giving effect to any limitation on exercise contained therein) and no shares remain issuable thereunder. During the three months ended March 31, 2019, 11.6 million Series B Warrants were exercised for approximately $11,609. As of March 31, 2019, 5,000 Series B Warrants remain outstanding. A summary of warrant activity during the three months ended March 31, 2019 is as follows (in thousands): Weighted Weighted Average Average Exercise Remaining Warrants Price Contractual Life Outstanding at December 31, 2018 - $ - - Assumed in merger 436 $ 20.59 4.2 Issued 15,244 $ 0.40 4.9 Exercised (13,192) $ 0.20 Cancelled - $ - Outstanding as of March 31, 2019 2,488 $ 4.99 4.7 Exercisable as of March 31, 2019 2,488 $ 4.99 4.7 The Series A and Series B warrants were recognized as a liability at their fair value upon issuance. The warrant liability is remeasured to the then fair value prior to their exercise or at period end for warrants that are unexercised and the gain or loss recognized in earnings during the period.

8. Stock-based Compensation

8. Stock-based Compensation	3 Months Ended
	Mar. 31, 2019
Warrants Expiring March 2023, Tranche 3 [Member]
Stock-based Compensation	8. Stock-based compensation The Company has a 2012 Stock Long Term Incentive Plan (the "2012 Plan"), which provides for the issuance of incentive and non-incentive stock options, restricted and unrestricted stock awards, stock unit awards and stock appreciation rights. Options and restricted stock units granted generally vest over a period of one to four years and have a maximum term of ten years from the date of grant. As of March 31, 2019, an aggregate of 373,798 shares of Common Stock were authorized under the Apricus 2012 Plan, of which 0 Common Stock were available for future grants. Upon completion of the Merger, the Company assumed the 2016 Equity Incentive Plan (the "2016 Plan") and awards outstanding under the 2016 Plan became awards for Common Stock. Effective as of the Merger, no further awards may be issued under the 2016 Plan. Stock options During the three months ended March 31, 2019, the Company granted 243,750 incentive stock options to employees with a weighted average exercise price per share of $2.20 and a 10 year term, subject to the terms and conditions of the 2012 Plan above. The stock options are subject to time vesting requirements. The stock options granted to employees vest 25% on the first anniversary of the grant and monthly thereafter over the next three years. During the three months ended March 31, 2019, the Company also granted 136,000 non-qualified stock options to non-employee directors with a weighted average exercise price per share of $2.33 and a 10 year term, subject to the terms and conditions of the 2012 Plan above. 72,000 of the stock options granted to non-employee directors vest 1/3 rd The fair value of stock option grants are estimated on the date of grant using the Black-Scholes option-pricing model. The Company was historically a private company and lacked company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies. The expected term of stock options granted is equal to the contractual term of the option award. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect for time periods approximately equal to the expected term of the award. Expected dividend yield is zero based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future. During the three months ended March 31, 2019, no stock options were exercised or forfeited. The following assumptions were used in determining the fair value of the stock options granted during the the three months ended March 31, 2019: March 31, 2019 Risk-free interest rate 2.4%-2.6% Volatility 109%-113% Dividend yield - % Expected term 5.04-6.97 Weighted average fair value $ 1.89 A summary of stock option activity during the three months ended March 31, 2019 is as follows (in thousands): Weighted Weighted- Total Average Average Remaining Aggregate Stock Exercise Contractual Intrinsic Options Price Life (in years) Value Outstanding as of December 31, 2018 31 $ 0.65 7.5 $ 84 Granted 380 2.25 9.9 422 Exercised - - Cancelled - - - - Outstanding as of March 31, 2019 411 $ 2.13 9.7 $ 506 Vested and expected to vest as of March 31, 2019 31 $ 0.65 7.5 $ 84 Exercisable as of March 31, 2019 31 $ 0.65 7.5 $ 84 The Company recorded $38,000 and $8,000 in stock-based compensation expense for the three months ended March 31, 2019 and 2018.

9. Related Party Transactions

9. Related Party Transactions	3 Months Ended
	Mar. 31, 2019
Related Party Transactions [Abstract]
Related Party Transactions	9. Related Party Transactions The Company had the following related party transaction for the three months ended March 31, 2019: IRRAS AB IRRAS AB ("IRRAS") is a commercial stage medical technology company of which a former director of the Company is also the President, Chief Executive Officer and director. In January 2018, the Company and IRRAS entered into a Sublease, pursuant to which the Company subleased to IRRAS excess capacity in its corporate headquarters. The sublease had a term of two years. On October 30, 2018, the Company and IRRAS entered into an amended and restated sublease, commencing January 1, 2019, pursuant to which the Company agreed to sublease to IRRAS the remainder of its San Diego, California location (the "IRRAS Restated Sublease"), which satisfied a closing condition related to the Merger. The IRRAS Restated Sublease has a term of one year and provides for aggregate payments due to the Company of approximately $0.4 million, which approximate fair value.

10. Commitments and Contingenci

10. Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	10. Commitments and contingencies Leases In March 2019, the Company entered into a nine-month office space rental agreement for its headquarters in New York, New York expiring November 2019. The rental agreement contains a base rent of approximately $8,000 per month. In December 2011, Apricus entered into a five-year lease agreement for its original headquarters in San Diego, California expiring December 31, 2016. In December 2015, Apricus amended the lease agreement to extend the term through January 31, 2020. The Company has an option to extend the lease an additional three years. The original lease term contained a base rent of approximately $24,000 per month with 3% annual escalations, plus a supplemental real estate tax and operating expense charge to be determined annually. In 2018, Apricus subleased excess capacity in its San Diego location to a subtenant under a non-cancellable lease. The sublease had a term of two years and aggregate payments due to Apricus of approximately $0.3 million. On October 30, 2018, Apricus amended and restated its sublease, commencing January 1, 2019, pursuant to which Apricus agreed to sublease the remainder of its San Diego location, which satisfied a closing condition related to the Merger. The amended and restated sublease has a term of one year and provides for aggregate payments due to the Company of approximately $0.4 million, which approximate fair value. Litigation As of March 31, 2019, there was no material litigation against the Company.

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Liquidity The Company had no revenues, incurred operating losses since inception, and expects to continue to incur significant operating losses for the foreseeable future and may never become profitable. As of March 31, 2019, the Company had $11.3 million in cash and an accumulated deficit of $40.3 million. The Company has historically funded its operations through the issuance of convertible notes (see note 5), sale of common stock (see note 3) and warrants (see note 6). The Company has an effective shelf registration statement on Form S-3 filed with the SEC under which it may offer from time to time any combination of debt securities, common and preferred stock and warrants. As of March 31, 2019, the Company had approximately $95.2 million available under its Form S-3 shelf registration statement. Under current SEC regulations, in the event the aggregate market value of the Company's common stock held by non-affiliates ("public float"), is less than $75.0 million, the amount it can raise through primary public offerings of securities in any twelve-month period using shelf registration statements is limited to an aggregate of one-third of the Company's public float. SEC regulations permit the Company to use the highest closing sales price of the Company's common stock (or the average of the last bid and last ask prices of the Company's common stock) on any day within 60 days of sales under the shelf registration statement. As of March 31, 2019, the Company's public float was approximately $68.3 million based on 15.2 million shares of the Company's common stock outstanding at a price of $4.50 per share, which was the closing sale price of the Company's common stock on January 31, 2019. As the Company's public float was less than $75.0 million as of March 31, 2019, the Company's usage of its S-3 shelf registration statement is limited. The Company still maintains the ability to raise funds through other means, such as through the filing of a registration statement on Form S-1 or in private placements. The rules and regulations of the SEC or any other regulatory agencies may restrict the Company's ability to conduct certain types of financing activities, or may affect the timing of and amounts it can raise by undertaking such activities. The accompanying unaudited condensed consolidated financial statements have been prepared assuming the Company will continue to operate as a going concern, which contemplates the realization of assets and settlement of liabilities in the normal course of business, and do not include any adjustments to reflect the possible future effects on the recoverability and classification of assets or the amounts and classifications of liabilities that may result from uncertainty related to its ability to continue as a going concern. The Company's future liquidity and capital funding requirements will depend on numerous factors, including: its ability to raise additional funds to finance its operations; its ability to maintain compliance with the listing requirements of The Nasdaq Capital Market ("Nasdaq"); the outcome, costs and timing of clinical trial results for the Company's current or future product candidates; the extent and amount of any indemnification claims; litigation expenses and the extent and amount of any indemnification claims; the emergence and effect of competing or complementary products; its ability to maintain, expand and defend the scope of its intellectual property portfolio, including the amount and timing of any payments the Company may be required to make, or that it may receive, in connection with the licensing, filing, prosecution, defense and enforcement of any patents or other intellectual property rights; its ability to retain its current employees and the need and ability to hire additional management and scientific and medical personnel; the terms and timing of any collaborative, licensing or other arrangements that it has or may establish; the trading price of its common stock; and its ability to increase the number of authorized shares outstanding to facilitate future financing events. The Company will likely need to raise substantial additional funds through one or more of the following: issuance of additional debt or equity, or the completion of a licensing transaction for one or more of the Company's pipeline assets. If the Company is unable to maintain sufficient financial resources, its business, financial condition and results of operations will be materially and adversely affected. This could affect future development and business activities and potential future clinical studies and/or other future ventures. Failure to obtain additional equity or debt financing will have a material, adverse impact on the Company's business operations. There can be no assurance that the Company will be able to obtain the needed financing on acceptable terms or at all. Additionally, equity or debt financings will likely have a dilutive effect on the holdings of the Company's existing stockholders. The accompanying unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto as of and for the year ended December 31, 2018 included in the Company's Annual Report on Form 10-K ("Annual Report") filed with the U.S. Securities and Exchange Commission (the "SEC") on March 28, 2019. The accompanying financial statements have been prepared by the Company in accordance with U.S. GAAP for interim financial information and in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. In the opinion of management, the accompanying unaudited condensed consolidated financial statements for the periods presented reflect all adjustments, consisting of only normal, recurring adjustments, necessary to fairly state the Company's financial position, results of operations and cash flows. The December 31, 2018 condensed consolidated balance sheet was derived from audited financial statements, but does not include all U.S. GAAP disclosures. The unaudited condensed consolidated financial statements for the interim periods are not necessarily indicative of results for the full year. The preparation of these unaudited condensed consolidated financial statements requires the Company to make estimates and judgments that affect the amounts reported in the financial statements and the accompanying notes. The Company's actual results may differ from these estimates under different assumptions or conditions.
Merger	Merger with Apricus Biosciences, Inc. On January 24, 2019, the Company completed the acquisition of Apricus Biosciences, Inc., a Nevada corporation ("Apricus"), in accordance with the terms of the Agreement and Plan of Merger Reorganization (the "Merger Agreement") entered into on July 30, 2018. Pursuant to the Merger Agreement, (i) a subsidiary of Apricus merged with and into Seelos Therapeutics, Inc., a Delaware corporation ("Seelos"), with Seelos (renamed as "Seelos Corporation") continuing as a wholly owned subsidiary of Apricus and the surviving corporation of the merger and (ii) Apricus was renamed as Seelos Therapeutics, Inc." (the "Merger"). The Merger was accounted for as a reverse recapitalization under United States generally accepted accounting principles ("U.S. GAAP") because the primary assets of Apricus were nominal following the close of the Merger. Seelos was determined to be the accounting acquirer based upon the terms of the Merger and other factors including: (i) Seelos stockholders and other persons holding securities convertible, exercisable or exchangeable directly or indirectly for Seelos common stock owned the majority of Apricus immediately following the effective time of the Merger, (ii) Seelos holds the majority (four of five) of board seats of the combined company and (iii) Seelos' management holds all key positions in the management of the combined company. Accordingly, the historical financial statements of Seelos Therapeutics Inc. became the Company's historical financial statements including the comparative prior periods. All references in the unaudited condensed consolidated financial statements to the number of shares and per-share amounts of common stock have been retroactively restated to reflect the exchange rate.
Use of Estimates	Use of estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. The most significant estimates in the Company's financial statements relate to the valuation of warrants, valuation of convertible notes payable, valuation of common stock and the valuation of stock options. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of expenses that are not readily apparent from other sources. Actual results may differ materially and adversely from these estimates. To the extent there are material differences between the estimates and actual results, the Company's future results of operations will be affected.
Fair Value of Financial Instruments	Fair Value Measurements The Company follows the accounting guidance in Accounting Standards Codification ("ASC") Topic 820, Fair Value Measurements and Disclosures ("ASC 820"), for its fair value measurements of financial assets and liabilities measured at fair value on a recurring basis. Under this accounting guidance, fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. The accounting guidance requires fair value measurements be classified and disclosed in one of the following three categories: Level 1: Quoted prices in active markets for identical assets or liabilities. Level 2: Observable inputs other than Level 1 prices, for similar assets or liabilities that are directly or indirectly observable in the marketplace. Level 3: Unobservable inputs which are supported by little or no market activity and that are financial instruments whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company's warrant liabilities and convertible notes were classified within Level 3 of the fair value hierarchy because their fair values were estimated by utilizing valuation models and significant unobservable inputs. The warrants and convertible notes were valued using a scenario-based discounted cash flow analysis. Two primary scenarios were considered and probability weighted to arrive at the valuation conclusion for each convertible note. The first scenario considers the value impact of conversion at the stated discount to the issue price in a qualified financing event, while the second scenario assumes the convertible notes are held to maturity. The following tables present information about the Company's financial assets and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values. There were no transfers between fair value measurement levels during the three months ended March 31, 2019: Fair Value Measurements as of March 31, 2019 (Level 1) (Level 2) (Level 3) Total Assets Cash $ 11,292 $ - $ - $ 11,292 Liabilities Warrant liabilities $ - $ - $ 4,458 $ 4,458
Fair Value Measurement	Fair Value Option As permitted under ASC Topic 825, Financial Instruments, ("ASC 825"), the Company had elected the fair value option to account for its convertible notes. In accordance with ASC 825, the Company records these convertible notes at fair value with changes in fair value recorded in the Statement of Operations. As a result of applying the fair value option, direct costs and fees related to the convertible notes were expensed as incurred and were not deferred.
Stock-Based Compensation	Stock-based compensation The Company expenses stock-based compensation to employees, non-employees and board members over the requisite service period based on the estimated grant-date fair value of the awards and forfeitures rates. The Company accounts for forfeitures as they occur. Stock-based awards with graded-vesting schedules are recognized on a straight-line basis over the requisite service period for each separately vesting portion of the award. The Company estimates the fair value of stock option grants using the Black-Scholes option pricing model, and the assumptions used in calculating the fair value of stock-based awards represent management's best estimates and involve inherent uncertainties and the application of management's judgment. All stock-based compensation costs are recorded in general and administrative or research and development costs in the statements of operations based upon the underlying individual's role at the Company.
Net Loss Per Share	Net Loss Per Share Basic loss per share is computed by dividing net loss applicable to common stockholders by the weighted average number of shares of common stock outstanding during each period. Diluted loss per share includes the effect, if any, from the potential exercise or conversion of securities, such as convertible debt, warrants and stock options that would result in the issuance of incremental shares of common stock. In computing the basic and diluted net loss per share applicable to common stockholders, the weighted average number of shares remains the same for both calculations due to the fact that when a net loss exists, dilutive shares are not included in the calculation as the impact is anti-dilutive. The following potentially dilutive securities outstanding as of March 31, 2019 and 2018 have been excluded from the computation of diluted weighted average shares outstanding, as they would be anti-dilutive (in thousands): As of March 31, 2019 2018 Outstanding stock options 411 31 Outstanding warrants 2,047 - Convertible notes - 104 2,458 135 Amounts in the table reflect the common stock equivalents of the noted instruments.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2016, the FASB issued Accounting Standards Update ("ASU") 2016-2, Leases In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820), Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement ("ASU 2018-13"). The amendments in this ASU require certain existing disclosure requirements in Topic 820 to be modified or removed, and certain new disclosure requirements to be added to the Topic. In addition, this ASU allows entities to exercise more discretion when considering fair value measurement disclosures. ASU 2018-13 will be effective for the Company beginning January 1, 2020 with early adoption permitted. The Company is in the process of evaluating the impact of ASU 2018-13 on its consolidated financial statements and related disclosures.

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Schedule of Fair Value Hierarchy for Warrant Liabilities	The following tables present information about the Company's financial assets and liabilities measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values. There were no transfers between fair value measurement levels during the three months ended March 31, 2019: Fair Value Measurements as of March 31, 2019 (Level 1) (Level 2) (Level 3) Total Assets Cash $ 11,292 $ - $ - $ 11,292 Liabilities Warrant liabilities $ - $ - $ 4,458 $ 4,458
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following potentially dilutive securities outstanding as of March 31, 2019 and 2018 have been excluded from the computation of diluted weighted average shares outstanding, as they would be anti-dilutive (in thousands): As of March 31, 2019 2018 Outstanding stock options 411 31 Outstanding warrants 2,488 - Convertible notes - 104 2,899 135 Amounts in the table reflect the common stock equivalents of the noted instruments.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Summary of Warrant Activity	A summary of warrant activity during the three months ended March 31, 2019 is as follows (in thousands): Weighted Weighted Average Average Exercise Remaining Warrants Price Contractual Life Outstanding at December 31, 2018 - $ - - Assumed in merger 436 $ 20.59 4.2 Issued 15,244 $ 0.40 4.9 Exercised (13,192) $ 0.20 Cancelled - $ - Outstanding as of March 31, 2019 2,488 $ 4.99 4.7 Exercisable as of March 31, 2019 2,488 $ 4.99 4.7

Equity Compensation Plans (Tabl

Equity Compensation Plans (Tables)	3 Months Ended
	Mar. 31, 2019
Share-based Payment Arrangement [Abstract]
Summary of Stock Option Activity	A summary of stock option activity during the three months ended March 31, 2019 is as follows (in thousands): Weighted Weighted- Total Average Average Remaining Aggregate Stock Exercise Contractual Intrinsic Options Price Life (in years) Value Outstanding as of December 31, 2018 31 $ 0.65 7.5 $ 84 Granted 380 2.25 9.9 422 Exercised - - Cancelled - - - - Outstanding as of March 31, 2019 411 $ 2.13 9.7 $ 506 Vested and expected to vest as of March 31, 2019 31 $ 0.65 7.5 $ 84 Exercisable as of March 31, 2019 31 $ 0.65 7.5 $ 84
Schedule of Valuation Assumptions for Stock Options	The following assumptions were used in determining the fair value of the stock options granted during the the three months ended March 31, 2019: March 31, 2019 Risk-free interest rate 2.4%-2.6% Volatility 109%-113% Dividend yield - % Expected term 5.04-6.97 Weighted average fair value $ 1.89

Organization and Description of

Organization and Description of Business, Merger with Apricus Biosciences, Inc. Reverse Stock Split - Narrative (Details)	3 Months Ended
	Mar. 31, 2019
Organization And Description Of Business Merger With Apricus Biosciences Inc. Reverse Stock Split - Narrative
Reverse stock split	On January 24, 2019, the Company completed the acquisition of Apricus Biosciences, Inc., a Nevada corporation ("Apricus"), in accordance with the terms of the Agreement and Plan of Merger Reorganization (the "Merger Agreement") entered into on July 30, 2018. Pursuant to the Merger Agreement, (i) a subsidiary of Apricus merged with and into Seelos Therapeutics, Inc., a Delaware corporation ("Seelos"), with Seelos (renamed as "Seelos Corporation") continuing as a wholly owned subsidiary of Apricus and the surviving corporation of the merger and (ii) Apricus was renamed as Seelos Therapeutics, Inc." (the "Merger"). The Merger was accounted for as a reverse recapitalization under United States generally accepted accounting principles ("U.S. GAAP") because the primary assets of Apricus were nominal following the close of the Merger. Seelos was determined to be the accounting acquirer based upon the terms of the Merger and other factors including: (i) Seelos stockholders and other persons holding securities convertible, exercisable or exchangeable directly or indirectly for Seelos common stock owned the majority of Apricus immediately following the effective time of the Merger, (ii) Seelos holds the majority (four of five) of board seats of the combined company and (iii) Seelos' management holds all key positions in the management of the combined company. Accordingly, the historical financial statements of Seelos Therapeutics Inc. became the Company's historical financial statements including the comparative prior periods. All references in the unaudited condensed consolidated financial statements to the number of shares and per-share amounts of common stock have been retroactively restated to reflect the exchange rate.

Summary of Significant Accounti

Summary of Significant Accounting Policies - Fair Value Warrant Liabilities Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Assets:
Cash	$ 11,292	$ 42
Liabilities:
Liabilities measured at fair value on a recurring basis	4,458
Warrant | Level 1 | Fair Value, Measurements, Recurring
Assets:
Cash	11,292
Liabilities:
Liabilities measured at fair value on a recurring basis	0
Warrant | Level 2 | Fair Value, Measurements, Recurring
Liabilities:
Liabilities measured at fair value on a recurring basis	0
Warrant | Level 3 | Fair Value, Measurements, Recurring
Liabilities:
Liabilities measured at fair value on a recurring basis	$ 4,458

Summary of Significant Accoun_2

Summary of Significant Accounting Policies - Net Loss Per Share - Antidilutive (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Anti-dilutive shares	2,899,000	135,000
Stock options
Anti-dilutive shares	411,000	31,000
Warrant
Anti-dilutive shares	2,488,000	0
Convertible Notes
Anti-dilutive shares	0	104,000

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies - Fair Value Valuation Warrant Assumptions (Details)	3 Months Ended
	Mar. 31, 2019$ / shares
Risk-free interest rate, minimum	2.40%
Risk-free interest rate, maximum	2.60%
Dividend yield	0.00%
Expected term (in years)	5 years
Weighted average fair value (USD per share)	$ 1.89

Organization and Summary of S_4

Organization and Summary of Significant Accounting Policies - Antidilutive Securities (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of securities that are antidilutive	2,899,000	135,000
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of securities that are antidilutive	411,000	31,000
Warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of securities that are antidilutive	2,488,000	0
Convertible notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Number of securities that are antidilutive	0	104,000

Business Combinations (Purchase

Business Combinations (Purchase Price Allocation and Narrative) (Details)	1 Months Ended
	Feb. 28, 2019	Jan. 31, 2019	May 31, 2017	Sep. 30, 2016
Ligand License
Business Combination, Separately Recognized Transactions, Description				On September 21, 2016, the Company entered into a License Agreement (the "License Agreement") with Ligand Pharmaceuticals Incorporated ("Ligand"), Neurogen Corporation and CyDex Pharmaceuticals, Inc. (collectively, the "Licensors"), pursuant to which, among other things, the Licensors granted to the Company an exclusive, perpetual, irrevocable, worldwide, royalty-bearing, nontransferable right and license under (i) patents related to a product known as Aplindore, which is now known as SLS-006, acetaminophen (as it may have been or may be modified for use in a product to be administered by any method in any form including, without limitation injection and intravenously, the sole active pharmaceutical ingredient of which is acetaminophen), which is now known as SLS-012, an H3 receptor antagonist, which is now known as SLS-010, and either or both of the Licensors' two proprietary CRTh2 antagonists, which are now known collectively as SLS-008 (collectively, the "Licensed Products"), and (ii) copyrights, trade secrets, moral rights and all other intellectual and proprietary rights related thereto. The Company is obligated to use commercially reasonable efforts to (a) develop the Licensed Products, (b) obtain regulatory approval for the Licensed Products in the United States, the European Union (either in its entirety or including at least one of France, Germany or, if at the time the United Kingdom is a member of the European Union, the United Kingdom), the United Kingdom, if at the time the United Kingdom is not a member of the European Union, Japan or the People's Republic of China, each of which is referred to as a Major Market, and (c) commercialize the Licensed Products in each country where regulatory approval is obtained. The Company has the exclusive right and sole responsibility and decision-making authority to research and develop any Licensed Products and to conduct all clinical trials and non-clinical studies the Company believes appropriate to obtain regulatory approvals for commercialization of the Licensed Products. The Company also has the exclusive right and sole responsibility and decision-making authority to commercialize any of the Licensed Products. As consideration for the grant of the rights and licenses under the License Agreement, the Company paid to Ligand a nominal option fee. As further partial consideration for the grant of the rights and licenses to the Company under the License Agreement, the Company was obligated pay to Ligand an aggregate of $1.3 million within 30 days after the closing of the issuance and sale by the Company of debt and/or equity securities for gross proceeds to the Company of at least $7.5 million. In connection with the closing of the Merger, the Company issued 392,307 shares of common stock to settle this obligation. As further partial consideration for the grant of the rights and licenses to the Company by Ligand under the License Agreement, the Company agreed to pay to Ligand certain one-time, non-refundable milestone payments upon the achievement of certain financing milestones, consisting of (i) the lesser of $3.5 million or 10% of the net proceeds to the company in the event of the Company's initial public offering or a financing transaction consummated in connection with a transaction as a result of which the Company's business becomes owned or controlled by an existing issuer with a class of securities registered under the Securities Exchange Act of 1934, as amended, and immediately after such transaction, the security holders of the Company as of immediately before such transaction own, as a result of such transaction, at least 35% of the equity securities or voting power of such issuer, or (ii) the lesser of $3.5 million or 10% of the net proceeds to the Company in the event the Company is acquired. In connection with the closing of the Merger, the Company issued 408,946 shares of common stock to settle this obligation. The Company recognized research and development expense totaling approximately $2.2 million during the period ended March 31, 2019 for the common stock issued in connection with the Merger. As further consideration for the grant of the rights and licenses to under the License Agreement, the Company agreed to pay to Ligand certain one-time, non-refundable regulatory milestone payments in connection with the Licensed Products, other than in connection with Aplindore for the indication of Parkinson's disease or Restless Leg Syndrome, consisting of (i) $750,000 upon submission of an application with the FDA or equivalent foreign body for a particular Licensed Product, (ii) $3.0 million upon FDA approval of an application for a particular Licensed Product, (iii) $1.125 million upon regulatory approval in a Major Market for a particular Licensed Product, and (iv) $1.125 million upon regulatory approval in a second Major Market for a particular Licensed Product. As further consideration for the grant of the rights and licenses to under the License Agreement, the Company agreed to pay to Ligand certain one-time, non-refundable regulatory milestone payments in connection with the Licensed Products in connection with Aplindore for the indication of Parkinson's disease or Restless Leg Syndrome, consisting of (i) $100,000 upon submission of an application with the FDA or equivalent foreign body for such a particular Licensed Product, (ii) $350,000 upon FDA approval of an application for such a particular Licensed Product, (iii) $125,000 upon regulatory approval in a Major Market for such a particular Licensed Product, and (iv) $125,000 upon regulatory approval in a second Major Market for such a particular Licensed Product. As further partial consideration for the grant of the rights and licenses under the License Agreement, the Company agreed to pay to Ligand certain one-time, non-refundable commercial milestone payments in connection with the Licensed Products, consisting of (i) $10.0 million upon the achievement of $1.0 billion of cumulative worldwide net sales of Licensed Products based upon Aplindore, (ii) $10.0 million upon the achievement of $1.0 billion of cumulative worldwide net sales of Licensed Products based upon an H3 receptor antagonist, (iii) $10.0 million upon the achievement of $1.0 billion of cumulative worldwide net sales of Licensed Products based upon acetaminophen (as it may have been or may be modified for use in a product to be administered by any method in any form including, without limitation injection and intravenously, the sole active pharmaceutical ingredient of which is acetaminophen), (iv) $10.0 million upon the achievement of $1.0 billion of cumulative worldwide net sales of Licensed Products based upon CRTh2 antagonists, (v) $20.0 million upon the achievement of $2.0 billion of cumulative worldwide net sales of Licensed Products based upon Aplindore, (vi) $20.0 million upon the achievement of $2.0 billion of cumulative worldwide net sales of Licensed Products based upon an H3 receptor antagonist, (vii) $20.0 million upon the achievement of $2.0 billion of cumulative worldwide net sales of Licensed Products based upon acetaminophen (as it may have been or may be modified for use in a product to be administered by any method in any form including, without limitation injection and intravenously, the sole active pharmaceutical ingredient of which is acetaminophen), and (viii) $20.0 million upon the achievement of $2.0 billion of cumulative worldwide net sales of Licensed Products based upon CRTh2 antagonists. The Company will also pay to Ligand middle single-digit royalties on aggregate annual net sales of Licensed Products other than in connection with Aplindore for the indication of Parkinson's disease or Restless Leg Syndrome in a country where such Licensed Products are covered under a licensed patent and a tiered incremental royalty in the upper single digit to lower double digit range on aggregate annual net sales of Licensed Products in connection with Aplindore for the indication of Parkinson's disease or Restless Leg Syndrome in a country where such Licensed Products are covered under a licensed patent. Additionally, the Company will pay to Ligand low single digit royalties on aggregate annual net sales of Licensed Products other than in connection with Aplindore for the indication of Parkinson's disease or Restless Leg Syndrome in a country where such Licensed Products are not covered under a licensed patent and a tiered incremental royalty in the lower single digit to middle single digit range on aggregate annual net sales of Licensed Products in connection with Aplindore for the indication of Parkinson's disease or Restless Leg Syndrome in a country where such Licensed Products are not covered under a licensed patent. The potential regulatory and commercial milestones are not yet considered probable, and no milestone payments have been accrued at March 31, 2019.
Vyera Assets
Business Combination, Separately Recognized Transactions, Description			On May 25, 2017, the Company entered into a non-binding term sheet to acquire TUR-002 (intranasal ketamine) ("TUR-002") from Vyera. During the year ended December 31, 2017, the Company recorded $400,000 in research and development expenses related to the non-refundable but creditable payments to continue to negotiate exclusively with Vyera while the Company continued to identify financing terms with other parties to provide the necessary funding to purchase TUR-002. On January 18, 2018, the Company and Vyera entered into an Amendment to the May 25, 2017 Term Sheet for TUR-002. The Company paid $100,000 as a non-refundable but creditable payment to continue to negotiate exclusively with Vyera to purchase TUR-002. On March 6, 2018, the Company entered into an Asset Purchase Agreement with Vyera, as amended by an amendment thereto entered into on May 18, 2018 (the "First Vyera Amendment") and an amendment thereto entered into on December 31, 2018 (the "Second Vyera Amendment" such agreement, as amended by the First Vyera Amendment and the Second Vyera Amendment, the "Vyera Asset Purchase Agreement"). Pursuant to the Vyera Asset Purchase Agreement, the Company agreed to acquire the assets (the "Vyera Assets"), and liabilities (the "Vyera Assumed Liabilities"), of Vyera related to a product candidate known as TUR-002 (intranasal ketamine), which is now known as SLS-002. The Company is obligated to use commercially reasonable efforts to seek regulatory approval in the United States for and commercialize SLS-002. The Company agreed that if it receives regulatory approval to commence a Phase III clinical trial for SLS-002 and no third party has alleged any claim of conflict, infringement, invalidity or other violation of any rights of others with regard to the Vyera Assets, then the Company must commence a Phase III clinical trial for SLS-002 by the date 18 months from the closing of the transactions contemplated by the Vyera Asset Purchase Agreement (the "Vyera Closing"), and if the Company fails to do so, the Vyera Asset Purchase Agreement will terminate immediately and become null and void and all of the Vyera Assets and the Vyera Assumed Liabilities will automatically be returned to Vyera. In the event that, prior to the fourth anniversary of the Vyera Closing, the Company sells, directly or indirectly, all or substantially all of the Vyera Assets to a third party, then the Company must pay Vyera an amount equal to 4% of the net proceeds actually received by the Company as an upfront payment in such sale. As partial consideration for the Vyera Assets, upon execution of the First Vyera Amendment, the Company paid to Vyera a non-refundable cash payment of $150,000. As further partial consideration for the Vyera Assets, upon public announcement of the entry by the Company and the Company into the Merger Agreement, the Company paid to Vyera a non-refundable cash payment of $150,000. As further partial consideration for the Vyera Assets the Company issued Vyera 191,529 shares of Common Stock and paid Vyera a non-refundable cash payment of $1,000,000. As further partial consideration for the Vyera Assets, the Company agreed to pay to Vyera certain one-time, non-refundable milestone payments consisting of (i) $3.5 million upon dosing of the first patient in a Phase III clinical trial for SLS-002, (ii) $10.0 million upon approval by the U.S. Food and Drug Administration (the "FDA") of a new drug application ("NDA"), with respect to SLS-002, (iii) $5.0 million upon approval by the European Medicines Agency (the "EMA") of the foreign equivalent to an NDA with respect to SLS-002 in a Major Market, (iv) $2.5 million upon approval by the EMA of the foreign equivalent to an NDA with respect to SLS-002 in a second Major Market, (v) $5.0 million upon the achievement of $250.0 million in net sales of SLS-002, (vi) $10.0 million upon the achievement of $500.0 million in net sales of SLS-002, (vii) $15.0 million upon the achievement of $1.0 billion in net sales of SLS-002, (viii) $20.0 million upon the achievement of $1.5 billion in net sales of SLS-002 and (ix) $25.0 million upon the achievement of $2.0 billion in net sales of SLS-002. The Company will also pay to Vyera royalty percentage in the mid-teens on aggregate annual net sales of SLS-002.
Bioblast Assets
Business Combination, Separately Recognized Transactions, Description	On February 15, 2019, the Company entered into an Asset Purchase Agreement (the "Bioblast Asset Purchase Agreement") with Bioblast. Pursuant to the Bioblast Asset Purchase Agreement, the Company acquired all of the assets of Bioblast relating to a therapeutic platform known as Trehalose (the "Bioblast Asset Purchase"). At the closing of the Bioblast Asset Purchase (the "Bioblast Closing"), the Company paid to Bioblast $1.5 million in cash, and the Company agreed to pay to Bioblast an additional $2.0 million in cash by the one-year anniversary of the Bioblast Closing. Accordingly, the Company recognized $3.5 million charge to research and development expense during the period ended March 31, 2019. Under the terms of the Bioblast Asset Purchase Agreement, the Company agreed to pay additional consideration to Bioblast upon the achievement of certain milestones in the future, as follows: (i) within 15 days following the completion of the Company's or the Company's affiliate's first Phase 2(b) clinical trial of Trehalose satisfying certain criteria, the Company will pay to Bioblast $8.5 million in cash; and (ii) within 15 days following the approval for commercialization by the FDA or the Health Products and Food Branch of Health Canada of the first NDA or New Drug Submission, respectively, of Trehalose filed by the Company or its affiliates, the Company will pay to Bioblast $8.5 million in cash. In addition, the Company agreed to pay Bioblast a cash royalty equal to 1% of the net sales of Trehalose. Under the terms of the Bioblast Asset Purchase, the Company assumed a collaborative agreement with Team Sanfilippo Foundation ("TSF"), a nonprofit medical research foundation founded by parents of children with Sanfilippo syndrome. TSF, upon approval by the FDA, plans to begin an open label, Phase 2(b) clinical trial in up to 20 patients with Sanfilippo syndrome, which is now known under the study name SLS-005. The Company will provide the clinical supply of Trehalose. The terms of the Bioblast Asset Purchase Agreement entitle the Company access to all clinical data from this trial.
Apricus Assets
Business Combination, Separately Recognized Transactions, Description		On January 24, 2019, the Company completed the acquisition of Apricus in accordance with the terms of the Merger Agreement. The Merger was accounted for as a reverse recapitalization under U.S. GAAP because the primary assets of Apricus were nominal at the close of the Merger. Seelos was determined to be the accounting acquirer based upon the terms of the Merger and other factors including: (i) Seelos stockholders and other persons holding securities convertible, exercisable or exchangeable directly or indirectly for Seelos common stock owned the majority of the Company immediately following the effective time of the Merger, (ii) Seelos holds the majority (four of five) of board seats of the combined company and (iii) Seelos' management holds all key positions in the management of the combined company. Upon the completion of the Merger, Seelos acquired no tangible assets and assumed no employees or operation from Apricus. Additionally, Apricus' intellectual property was considered to have no value. The remaining Apricus liabilities had a fair value of approximately $300 thousand. In connection with the Merger, Seelos entered into a Contingent Value Rights Agreement (the "CVR Agreement"). Pursuant to the CVR Agreement, Apricus stockholders received one CVR for each share of Apricus common stock held of record immediately prior to the closing of the merger. Each CVR represents the right to receive payments based on Apricus' Vitaros assets. In particular, CVR holders will be entitled to receive 90% of any cash payments (or the fair market value of any non-cash payments) exceeding $500,000 received, during a period of ten years from the closing of the merger, based on the sale or out-licensing of Apricus' Vitaros intangible asset, including any milestone payments (the "Contingent Payments"), less reasonable transaction expenses. After the completion of the merger, Seelos will be entitled to retain the first $500,000 and 10% of any Contingent Payments. Seelos assigned no value to the Vitaros intangible asset or the CVR in the acquisition accounting.

Covertible Notes (Narrative) (D

Covertible Notes (Narrative) (Details)	3 Months Ended
	Mar. 31, 2019
Covertible Notes Narrative
Long-term Debt, Description	From May 2017 to October 2018, the Company entered into convertible note agreements with investors. The aggregate principal amount of the Notes was $2.3 million which were due no later than April 30, 2019 with simple interest at the rate of 8% per annum. The Notes automatically converted, upon the issuance of preferred stock of the Company for capital-raising purposes occurring on or prior to the Notes' maturity date resulting in gross proceeds in excess of a specific amount, into shares of common stock of the Company by dividing the then-outstanding balance of each convertible note by 80% or 90%, depending on the terms for each note, of the lowest purchase price per share paid, or $9.70 to $10.91 per share, respectively, by another investor in the qualifying financing, which condition was satisfied by the Pre-Merger Financing. The Notes are carried at fair value. The Company recognized an adjustment to for changes in the Notes fair value of $0.1 million and $6 thousand during the periods ended March 31, 2019 and 2018, respectively. In connection with the closing of the Merger, the Notes plus unpaid interest were converted into 172,295 shares of Common Stock at a price of $9.70 or $10.91 per share.

Stockholders' Equity - Septembe

Stockholders' Equity - September 2018 Financing (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Class of Stock [Line Items]
Change in fair value of warrant liability	$ 18,050	$ 0

Stockholders' Equity - Septem_2

Stockholders' Equity - September 2017 Financing (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Class of Stock [Line Items]
Amendment of equity classified warrants	$ 5,020	$ 0

Stockholders' Equity - Septem_3

Stockholders' Equity - September 2016 Financing (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Stockholders Equity Note [Line Items]
Change in fair value of warrant liability	$ 18,050	$ 0

Stockholders' Equity - Warrant

Stockholders' Equity - Warrant Narrative (Details)	3 Months Ended
	Mar. 31, 2019$ / sharesshares
Series A
Class of Warrant or Right, Title of Security Warrants or Rights Outstanding	Common stock
Warrant Description	The Series A Warrants were initially exercisable for 1,463,519 shares of Common Stock at an exercise price per share equal to $4.15, which was adjusted to 2,640,128 shares of the Common Stock at an exercise price per share equal to $2.3005 on February 27, 2019 and which was further adjusted to 3,629,023 shares of Common Stock at an exercise price per share equal to $1.6736 on March 7, 2019, in each case, pursuant to the terms thereof. The Series A Warrants were immediately exercisable upon issuance and have a term of five years from the date of issuance. During the three months ended March 31, 2019, 1.6 million Series A Warrants were exercised for approximately $2.6 million. As of March 31, 2019, 2.0 million Series A Warrants remain outstanding at an exercise price of $1.6736 per share.
Warrant Outstanding	2,000,000
Exercise Price of Warrant | $ / shares	$ 1.6736
Series B
Class of Warrant or Right, Title of Security Warrants or Rights Outstanding	Common stock
Warrant Description	The Series B Warrants were initially exercisable for no shares of Common Stock, which was adjusted to 7,951,090 shares of Common Stock on February 27, 2019 and which was further adjusted to 11,614,483 shares of Common Stock on March 7, 2019, in each case, pursuant to the terms thereof. The Series B Warrants have an exercise price of $0.001, were immediately exercisable upon issuance and will expire on the day following the later to occur of (i) the Reservation Date, and (ii) the date on which the Series B Warrants have been exercised in full (without giving effect to any limitation on exercise contained therein) and no shares remain issuable thereunder. During the three months ended March 31, 2019, 11.6 million Series B Warrants were exercised for approximately $11,609. As of March 31, 2019, 5,000 Series B Warrants remain outstanding.
Warrant Outstanding	5,000

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Warrant Activity (Details)	3 Months Ended
	Mar. 31, 2019$ / sharesshares
Common Shares Issuable upon Exercise
Outstanding, beginning balance (in shares) | shares	0
Assumed in merger | shares	436,000
Issued (in shares) | shares	15,244,000
Exercised (in shares) | shares	(13,192,000)
Cancelled (in shares) | shares	0
Outstanding, ending balance (in shares) | shares	2,488,000
Exercisable at balance sheet date (in shares) | shares	2,488,000
Weighted Average Exercise Price
Outstanding, beginning balance (in usd per share) | $ / shares	$ 0
Assumed in merger (in usd per share) | $ / shares	20.59
Issued (in usd per share) | $ / shares	0.40
Exercised (in usd per share) | $ / shares	0.20
Cancelled (in usd per share) | $ / shares	0
Outstanding, ending balance (in usd per share) | $ / shares	4.99
Exercisable at balance sheet date (in dollars per share) | $ / shares	$ 4.99
Warrant Average Remaing Contractual Life
Warrants, outstanding, beginning	0 years
Warrants, outstanding, ending	4 years 252 days
Warrants exercisable	4 years 252 days

Equity Compensation Plans - Nar

Equity Compensation Plans - Narrative (Details) - $ / shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares authorized for issuance (shares)	373,798
Common shares available for future grants (shares)	0
Stock options exercised (shares)	0
Stock options granted (shares)	380,000
Weighted average exercise price per share	$ 2.25
Dividend yield	0.00%
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options vesting period	3 years
Term of options	10 years
Stock options granted (shares)	243,750
Weighted average exercise price per share	$ 2.32
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options vesting period		3 years
Term of options		10 years
Stock options granted (shares)		136,000
Weighted average exercise price per share		$ 2.33

Equity Compensation Plans - Sum

Equity Compensation Plans - Summary of Stock Option Activity (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Number of Shares
Outstanding, beginning of period (shares)	31,000
Granted in Period (shares)	380,000
Exercised in Period (shares)	0
Cancelled (shares)	0
Outstanding, end of period (shares)	411,000
Vested and expected to vest, end of period (shares)	31,000
Weighted Average Exercise Price
Outstanding, beginning of period (USD per share)	$ 0.65
Granted in Period (USD per share)	2.25
Exercised in Period (USD per share)	0
Cancelled (USD per share)	0
Outstanding, end of period (USD per share)	2.13
Vested and expected to vest stock, end of period (USD per share)	0.65
Exercisable, end of period (USD per share)	$ 0.65
Weighted Average Remaining Contractual Life (in years)
Outstanding (in years)	9 years 252 days
Weighted Average Remaining Contractual Life (in years) of vested and expected to vest stock options	7 years 180 days
Weighted Average Remaining Contractual Life (in years) of exercisable stock options	7 years 180 days
Total Aggregate Intrinsic Value
Total aggregate intrinsic value shares outstanding		$ 50,600
Total aggregate intrinsic value of vested or expected to vest stock options		8,400
Total aggregate intrinsic value of exercisable stock options		$ 8,400

Equity Compensation Plans - Ass

Equity Compensation Plans - Assumptions Of Black-Scholes Option Grant - Narrative (Details)	3 Months Ended
	Mar. 31, 2019$ / shares
Share-based Payment Arrangement [Abstract]
Risk-free interest rate, minimum	2.40%
Risk-free interest rate, maximum	2.60%
Volatility, minimum	109.00%
Volatility, maximum	113.00%
Dividend yield	0.00%
Expected term (in years)	5 years
Weighted average fair value	$ 1.89

Equity Compensation Plans - Sto

Equity Compensation Plans - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 38	$ 8

Related Party Transactions - Na

Related Party Transactions - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Related Party Transactions [Abstract]
Sublease, term of contract (years)	1 year
Future sublease payments receivable from related party		$ 0.4
Related Party Transaction, Description of Transaction	The Company had the following related party transaction for the three months ended March 31, 2019: IRRAS AB IRRAS AB ("IRRAS") is a commercial stage medical technology company of which a former director of the Company is also the President, Chief Executive Officer and director. In January 2018, the Company and IRRAS entered into a Sublease, pursuant to which the Company subleased to IRRAS excess capacity in its corporate headquarters. The sublease had a term of two years. On October 30, 2018, the Company and IRRAS entered into an amended and restated sublease, commencing January 1, 2019, pursuant to which the Company agreed to sublease to IRRAS the remainder of its San Diego, California location (the "IRRAS Restated Sublease"), which satisfied a closing condition related to the Merger. The IRRAS Restated Sublease has a term of one year and provides for aggregate payments due to the Company of approximately $0.4 million, which approximate fair value.

Commitments and contingencies -

Commitments and contingencies - Leases - Narrative (Details)	3 Months Ended
	Mar. 31, 2019
Commitments And Contingencies - Leases - Narrative
Operating Lease, Description	In March 2019, the Company entered into a nine-month office space rental agreement for its headquarters in New York, New York expiring November 2019. The rental agreement contains a base rent of approximately $8,000 per month. In December 2011, Apricus entered into a five-year lease agreement for its original headquarters in San Diego, California expiring December 31, 2016. In December 2015, Apricus amended the lease agreement to extend the term through January 31, 2020. The Company has an option to extend the lease an additional three years. The original lease term contained a base rent of approximately $24,000 per month with 3% annual escalations, plus a supplemental real estate tax and operating expense charge to be determined annually.
Operating Sublease	In 2018, Apricus subleased excess capacity in its San Diego location to a subtenant under a non-cancellable lease. The sublease had a term of two years and aggregate payments due to Apricus of approximately $0.3 million. On October 30, 2018, Apricus amended and restated its sublease, commencing January 1, 2019, pursuant to which Apricus agreed to sublease the remainder of its San Diego location, which satisfied a closing condition related to the Merger. The amended and restated sublease has a term of one year and provides for aggregate payments due to the Company of approximately $0.4 million, which approximate fair value.