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Document And Entity Information - USD ($)	12 Months Ended
Document And Entity Information - USD ($)	Dec. 31, 2018	Feb. 15, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Entity Registrant Name	TG THERAPEUTICS, INC.
Entity Central Index Key	0001001316
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		83,870,546
Entity Public Float			$ 917,401,544
Trading Symbol	TGTX

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 41,958	$ 56,718
Short-term investment securities	26,848	27,999
Interest receivable	95	108
Prepaid research and development	9,691	8,056
Other current assets	439	437
Total current assets	79,031	93,318
Restricted cash	1,241	587
Leasehold interest, net	2,294	2,429
Equipment, net	251	248
Goodwill	799	799
Total assets	83,616	97,381
Current liabilities:
Accounts payable and accrued expenses	36,377	25,877
Accrued compensation	2,258	1,800
Current portion of deferred revenue	152	152
Notes payable	67	128
Total current liabilities	38,854	27,957
Deferred rent	1,462	1,364
Deferred revenue, net of current portion	914	1,067
Long-term liabilities	18,350	0
Total liabilities	59,580	30,388
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.001 par value per share (10,000,000 shares authorized, none issued and outstanding as of December 31, 2018 and 2017)	0	0
Common stock, $0.001 par value per share (150,000,000 shares authorized, 83,911,855 and 73,181,750 shares issued, 83,870,546 and 73,140,441 shares outstanding at December 31, 2018 and 2017, respectively)	84	73
Additional paid-in capital	552,531	422,017
Treasury stock, at cost, 41,309 shares at December 31, 2018 and 2017	(234)	(234)
Accumulated deficit	(528,345)	(354,863)
Total stockholders' equity	24,036	66,993
Total liabilities and stockholders' equity	$ 83,616	$ 97,381

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	83,911,855	73,181,750
Common stock, shares outstanding	83,870,546	73,140,441
Treasury stock, shares	41,309	41,309

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
License revenue	$ 152	$ 152	$ 152
Research and development:
Non cash stock expense associated with in-licensing agreements	4,000	0	0
Noncash compensation	5,598	5,647	2,742
Other research and development	149,793	96,886	66,490
Total research and development	159,391	102,533	69,232
General and administrative:
Noncash compensation	7,288	10,298	4,767
Other general and administrative	7,873	6,033	5,122
Total general and administrative	15,161	16,331	9,889
Total costs and expenses	174,552	118,864	79,121
Operating loss	(174,400)	(118,712)	(78,969)
Other (income) expense:
Interest income	(857)	(295)	(323)
Other (income) expense	(61)	59	(393)
Total other income, net	(918)	(236)	(716)
Net loss	$ (173,482)	$ (118,476)	$ (78,253)
Basic and diluted net loss per common share (in dollars per share)	$ (2.30)	$ (1.91)	$ (1.60)
Weighted average shares used in computing basic and diluted net loss per common share (in shares)	75,466,813	62,069,570	49,041,354

Consolidated Statements of Equity - USD ($) $ in Thousands	Common Stock [Member]	Contingently Issuable Share [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Total
Balance at Dec. 31, 2015	$ 54		$ 259,887	$ (234)	$ (158,134)	$ 101,573
Balance (in shares) at Dec. 31, 2015	54,095,110	6		41,309
Issuance of common stock in connection with exercise of warrants			618			618
Issuance of common stock in connection with exercise of warrants (in shares)	273,370
Issuance of common stock in connection with conversion of notes payable			33			33
Issuance of common stock in connection with conversion of notes payable (in shares)	3,710
Issuance of restricted stock	$ 2		(2)
Issuance of restricted stock (in shares)	1,924,639
Forfeiture of restricted stock (in shares)	(46,773)
Issuance of common stock in At-the-Market offering (net of offering costs)			4,386			4,386
Issuance of common stock in At-the-Market offering (net of offering costs) (in shares)	570,366
Compensation in respect of restricted stock granted to employees, directors and consultants			7,510			7,510
Adjustment to contingently issuable shares		$ (6)
Net loss					(78,253)	(78,253)
Balance at Dec. 31, 2016	$ 57		272,432	$ (234)	(236,387)	35,868
Balance (in shares) at Dec. 31, 2016	56,820,422	0		41,309
Issuance of common stock in connection with exercise of warrants			2,142			2,143
Issuance of common stock in connection with exercise of warrants (in shares)	887,585
Issuance of restricted stock	$ 2		(2)
Issuance of restricted stock (in shares)	1,836,511
Forfeiture of restricted stock (in shares)	(53,875)
Issuance of common stock in public offering (net of offering costs of $3.6 million)	$ 6		53,634			53,640
Issuance of common stock in public offering (net of offering costs of $3.6 million) (in shares)	5,897,436
Issuance of common stock in At-the-Market offering (net of offering costs)	$ 8		77,865			77,873
Issuance of common stock in At-the-Market offering (net of offering costs) (in shares)	7,793,671
Compensation in respect of restricted stock granted to employees, directors and consultants			15,945			15,945
Net loss					(118,476)	(118,476)
Balance at Dec. 31, 2017	$ 73		422,017	$ (234)	(354,863)	66,993
Balance (in shares) at Dec. 31, 2017	73,181,750	0		41,309
Issuance of restricted stock	$ 2		(2)
Issuance of restricted stock (in shares)	1,562,211
Forfeiture of restricted stock (in shares)	(191,196)
Issuance of common stock in At-the-Market offering (net of offering costs)	$ 9		113,630			113,639
Issuance of common stock in At-the-Market offering (net of offering costs) (in shares)	9,025,222
Compensation in respect of restricted stock granted to employees, directors and consultants			12,886			12,886
Shares issued in connection with in-licensing agreements			4,000			4,000
Shares issued in connection with in-licensing agreements (in shares)	333,868
Net loss					(173,482)	(173,482)
Balance at Dec. 31, 2018	$ 84		$ 552,531	$ (234)	$ (528,345)	$ 24,036
Balance (in shares) at Dec. 31, 2018	83,911,855	0		41,309

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Consolidated net loss	$ (173,482)	$ (118,476)	$ (78,253)
Adjustments to reconcile consolidated net loss to net cash used in operating activities:
Gain on sale of long-term securities	0	0	(33)
Noncash stock compensation expense	12,886	15,945	7,510
Shares issued in connection with in-licensing agreement	4,000	0	0
Depreciation	88	82	63
Amortization of premium on investment securities	(119)	61	459
Change in fair value of notes payable and accrued interest	(61)	59	(110)
Changes in assets and liabilities:
(Increase) decrease in other current assets	(1,638)	(2,665)	3,565
Decrease (increase) in leasehold interest	135	125	(2,042)
Decrease (increase) in accrued interest receivable	14	(25)	102
Decrease (increase) in other assets	0	162	(5)
Increase in accounts payable and accrued expenses	10,957	11,020	6,493
Increase in other liabilities	18,350	0	0
Increase in deferred rent	97	104	816
Decrease in deferred revenue	(152)	(152)	(152)
Net cash used in operating activities	(128,925)	(93,760)	(61,587)
CASH FLOWS FROM INVESTING ACTIVITIES
Proceeds from maturity of short-term securities	32,500	19,800	29,500
Investment in held-to-maturity securities	(31,230)	(28,006)	(15,200)
Purchases of equipment	(90)	(2)	(344)
Proceeds from the sale of long-term securities	0	0	12,589
Net cash provided by (used in) investing activities	1,180	(8,208)	26,545
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from sale of common stock, net	113,639	131,516	4,411
Proceeds from the exercise of warrants	0	2,143	618
Deferred financing costs paid	0	0	(13)
Net cash provided by financing activities	113,639	133,659	5,016
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(14,106)	31,691	(30,026)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT BEGINNING OF YEAR	57,305	25,614	55,640
CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT END OF YEAR	43,199	57,305	25,614
Reconciliation to amounts on consolidated balance sheets:
Total cash, cash equivalents and restricted cash	43,199	57,305	25,614
NONCASH TRANSACTIONS
Reclassification of deferred financing costs to additional paid-in capital	0	(3)	(25)
Conversion of convertible notes payable to common stock	$ 0	$ 0	$ 33

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

DESCRIPTION OF BUSINESS

We are a biopharmaceutical company dedicated to developing and delivering medicines for patients with B-cell mediated diseases, including Chronic Lymphocytic Leukemia (CLL), non-Hodgkin’s Lymphoma (NHL) and Multiple Sclerosis (MS). We have developed a robust B-cell directed research and development (R&D) platform for identification of key B-cell pathways of interest and rapid clinical testing. Currently, we have five B-cell targeted drug candidates in clinical development, with the lead two therapies, ublituximab (TG-1101) and umbralisib (TGR-1202), in pivotal trials for CLL, NHL and MS. Ublituximab is a novel anti-CD20 monoclonal antibody (mAb) that has been glycoengineered for enhanced potency over first generation antibodies. Umbralisib is an oral, once daily inhibitor of PI3K delta. Umbralisib also uniquely inhibits CK1-epsilon, which may allow it to overcome certain tolerability issues associated with first generation PI3K delta inhibitors. When used together in combination therapy, ublituximab and umbralisib are referred to as ("U2"), or "1303". Additionally, in early clinical development we have an anti-PD-L1 monoclonal antibody referred to as TG-1501, an oral Bruton’s Tyrosine Kinase (“BTK”) inhibitor referred to as TG-1701, and an anti-CD47/CD19 bispecific antibody referred to as TG-1801.

We also actively evaluate complementary products, technologies and companies for in-licensing, partnership, acquisition and/or investment opportunities. To date, we have not received approval for the sale of any of our drug candidates in any market and, therefore, have not generated any product sales from our drug candidates.

LIQUIDITY AND CAPITAL RESOURCES

We have incurred operating losses since our inception, and expect to continue to incur operating losses for the foreseeable future and may never become profitable. As of December 31, 2018, we have an accumulated deficit of $528.3 million.

Our major sources of cash have been proceeds from the private placement and public offering of equity securities, and in 2019 from our loan and security agreement executed with Hercules (See Note 14 for more information). We have not yet commercialized any of our drug candidates and cannot be sure if we will ever be able to do so. Even if we commercialize one or more of our drug candidates, we may not become profitable. Our ability to achieve profitability depends on many factors, including our ability to obtain regulatory approval for our drug candidates; successfully complete any post-approval regulatory obligations; and successfully commercialize our drug candidates alone or in partnership. We may continue to incur substantial operating losses even if we begin to generate revenues from our drug candidates.

As of December 31, 2018, we had $68.9 million in cash and cash equivalents, investment securities, and interest receivable. The Company believes its cash, cash equivalents, investment securities, and interest receivable on hand as of December 31, 2018 combined with the additional capital being raised in the first quarter of 2019 and flexible vendor payment arrangements (see Notes 6 and 14) will be sufficient to fund the Company’s planned operations into mid 2020. The actual amount of cash that we will need to operate is subject to many factors, including, but not limited to, the timing, design and conduct of clinical trials for our drug candidates. We are dependent upon significant future financing to provide the cash necessary to execute our current operations, including the commercialization of any of our drug candidates.

Our common stock is quoted on the Nasdaq Capital Market and trades under the symbol “TGTX.”

RECENTLY ISSUED ACCOUNTING STANDARDS

In July 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update (“ASU”) No. 2018-11, “Leases - Targeted Improvements” (“ASU 2018-11”) as an update to ASU 2016-02, Leases (“ASU 2016-02” or “Topic 842”) issued on February 25, 2016. ASU 2016-02 is effective for public business entities for fiscal years beginning January 1, 2019. ASU 2016-02 required companies to adopt the new leases standard at the beginning of the earliest period presented in the financial statements, which is January 1, 2017, using a modified retrospective transition method where lessees must recognize lease assets and liabilities for all leases even though those leases may have expired before the effective date of January 1, 2017. Lessees must also provide the new and enhanced disclosures for each period presented, including the comparative periods.

ASU 2018-11 provides an entity with an additional (and optional) transition method to adopt the new leases standard. Under this new transition method, an entity initially applies the new lease standard at the adoption date and recognizes a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Consequently, an entity’s reporting for the comparative periods presented in the financial statements in which it adopts the new lease standard will continue to be in accordance with ASC 840, Leases. An entity that elects this additional (and optional) transition method must provide the required ASC 840 disclosures for all periods that continue to be in accordance with ASC 840. The amendments do not change the existing disclosure requirements in ASC 840.

ASU 2018-11 is effective for public business entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, with earlier adoption permitted. The Company adopted ASU 2018-11 on January 1, 2019 using a modified retrospective method and will not restate comparative periods. We elected the package of practical expedients permitted under the transition guidance, which allows us to carryforward our historical lease classification and our assessment on whether a contract is or contains a lease. The adoption of this guidance resulted in the addition of material balances of right of use assets and lease liabilities to our consolidated balance sheets at January 1, 2019, primarily relating to our lease of office space (see Note 9). We do not currently expect a material impact to our consolidated statements of operations as a result of this standard.

In June 2018, the FASB issued ASU No. 2018-07, “Improvements to Nonemployee Share-Based Payment Accounting” (“ASU 2018-07”). ASU 2018-07 expands the scope of FASB Topic 718, Compensation – Stock Compensation (“Topic 718”) to include share-based payment transactions for acquiring goods and services from nonemployees. An entity should only remeasure equity-classified awards for which a measurement date has not been established through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. Upon transition, the entity is required to measure these nonemployee awards at fair value as of the adoption date. The entity must not remeasure assets that are completed. Disclosures required at transition include the nature of and reason for the change in accounting principle and, if applicable, quantitative information about the cumulative effect of the change on retained earnings or other components of equity.

ASU 2018-07 is effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. Early adoption is permitted, but no earlier than an entity’s adoption date of Topic 606. The Company adopted ASU 2018-07 on January 1, 2019. The adoption of ASU 2018-07 did not have a material effect on our consolidated financial statements as of January 1, 2019. The adoption of ASU 2018-07 had no impact on nonemployee performance awards as they are measured based on the outcome that is probable.

In May 2017, the FASB issued ASU No. 2017-09, “Scope of Modification Accounting” (“ASU 2017-09”). ASU 2017-09 provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting. An entity should account for the effects of a modification unless all the following are met:

●

The fair value (or calculated value or intrinsic value, if such an alternative measurement method is used) of the modified award is the same as the fair value (or calculated value or intrinsic value, if such an alternative measurement method is used) of the original award immediately before the original award is modified. If the modification does not affect any of the inputs to the valuation technique that the entity uses to value the award, the entity is not required to estimate the value immediately before and after the modification.

●	The vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before the original award is modified.

●	The classification of the modified award as an equity instrument or a liability instrument is the same as the classification of the original award immediately before the original award is modified.

ASU 2017-09 is effective for annual and interim periods beginning on or after December 15, 2017. Early adoption is permitted for public business entities for reporting periods for which financial statements have not yet been issued, and all other entities for reporting periods for which financial statements have not yet been made available for issuance. The amendments should be applied prospectively to an award modified on or after the adoption date. The Company adopted ASU 2017-09 on January 1, 2018. The adoption of ASU 2017-09 did not have a material effect on our consolidated financial statements as of and for the year ended December 31, 2018.

In November 2016, the FASB issued ASU No. 2016-18, “Statement of Cash Flows – Restricted Cash” (“ASU 2016-18”). ASU 2016-18 requires that a statement of cash flows explain the change during the period for the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. ASU 2016-18 does not provide a definition of restricted cash or restricted cash equivalents, and does not change the balance sheet presentation for such items. The Company adopted ASU 2016-18 on January 1, 2018. The adoption of ASU 2016-18 did not have a material effect on our consolidated financial statements as of December 31, 2018.

In May 2014, the FASB issued ASU No. 2014-09, "Revenue from Contracts with Customers" (Topic 606) (“ASU 2014-09”), which supersedes all existing revenue recognition requirements, including most industry-specific guidance. ASU 2014-09 provides a single set of criteria for revenue recognition among all industries. The new standard requires a company to recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration that the Company expects to receive for those goods or services.

ASU 2014-09 includes guidance for determining whether a license transfers to a customer at a point in time or over time based on the nature of the entity’s promise to the customer. To determine whether the entity’s promise is to provide a right to access its intellectual property or a right to use its intellectual property, the entity should consider the nature of the intellectual property to which the customer will have rights.

ASU 2014-09 is effective for interim and annual periods beginning after December 15, 2017. The standard allows for two transition methods - full retrospective, in which the standard is applied to each prior reporting period presented, or modified retrospective, in which the cumulative effect of initially applying the standard is recognized at the date of initial adoption. The Company adopted ASU 2014-09 on January 1, 2018, using the modified retrospective approach. The adoption of ASU 2014-09 did not have a material effect on our consolidated financial statements as of December 31, 2018.

Other pronouncements issued by the FASB or other authoritative accounting standards with future effective dates are either not applicable or not significant to our condensed consolidated financial statements.

USE OF ESTIMATES

The preparation of financial statements in conformity with U.S. generally accepted accounting principles (“GAAP”) requires management to make estimates and judgments that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the applicable reporting period. On an ongoing basis, we evaluate our estimates and judgments, including those related to accrued expenses and stock-based compensation. Actual results could differ from those estimates. Such differences could be material to the financial statements.

CASH AND CASH EQUIVALENTS

We treat liquid investments with original maturities of less than three months when purchased as cash and cash equivalents.

RESTRICTED CASH

We record cash pledged or held in trust as restricted cash. As of December 31, 2018 and December 31, 2017, we have approximately $1.2 million and $0.6 million, respectively, of restricted cash pledged to secure a line of credit as a security deposit for an Office Agreement (see Note 9).

INVESTMENT SECURITIES

Investment securities at both December 31, 2018 and 2017 consist of short-term government securities. We classify these securities as held-to-maturity. Held-to-maturity securities are those securities in which we have the ability and intent to hold the security until maturity. Held-to-maturity securities are recorded at amortized cost, adjusted for the amortization or accretion of premiums or discounts. Premiums and discounts are amortized or accreted over the life of the related held-to-maturity security as an adjustment to yield using the effective interest method.

A decline in the market value of any investment security below cost, that is deemed to be other than temporary, results in a reduction in the carrying amount to fair value. The impairment is charged to operations and a new cost basis for the security is established. Other-than-temporary impairment charges are included in interest and other income (expense), net. Unrealized gains, if determined to be temporary, are included in accumulated other comprehensive income in equity. Dividend and interest income are recognized when earned.

CREDIT RISK

Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents and short-term investments. The Company maintains its cash and cash equivalents and short-term investments with high-credit quality financial institutions. At times, such amounts may exceed federally-insured limits.

REVENUE RECOGNITION

Effective January 1, 2018, the Company began recognizing revenue under ASC Topic 606, Revenue from Contracts with Customers (“ASC 606”), using the modified retrospective transition method. The impact of adopting the new revenue standard was not material to our consolidated financial statements and there was no adjustment to beginning retained earnings on January 1, 2018. The core principle of this new revenue standard is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The following five steps are applied to achieve that core principle:

●	Step 1: Identify the contract with the customer

●	Step 2: Identify the performance obligations in the contract

●	Step 3: Determine the transaction price

●	Step 4: Allocate the transaction price to the performance obligations in the contract

●	Step 5: Recognize revenue when the company satisfies a performance obligation

In order to identify the performance obligations in a contract with a customer, a company must assess the promised goods or services in the contract and identify each promised good or service that is distinct. A performance obligation meets ASC 606’s definition of a “distinct” good or service (or bundle of goods or services) if both of the following criteria are met:

●	The customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (i.e., the good or service is capable of being distinct).

●	The entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (i.e., the promise to transfer the good or service is distinct within the context of the contract).

If a good or service is not distinct, the good or service is combined with other promised goods or services until a bundle of goods or services is identified that is distinct.

The transaction price is the amount of consideration to which an entity expects to be entitled in exchange for transferring promised goods or services to a customer, excluding amounts collected on behalf of third parties (for example, some sales taxes). The consideration promised in a contract with a customer may include fixed amounts, variable amounts, or both. Variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved.

The transaction price is allocated to each performance obligation on a relative standalone selling price basis. The transaction price allocated to each performance obligation is recognized when that performance obligation is satisfied, at a point in time or over time as appropriate.

RESEARCH AND DEVELOPMENT COSTS

Generally, research and development costs are expensed as incurred. Nonrefundable advance payments for goods or services that will be used or rendered for future research and development activities are deferred and amortized over the period that the goods are delivered or the related services are performed, subject to an assessment of recoverability. We make estimates of costs incurred in relation to external clinical research organizations, or CROs, and clinical site costs. We analyze the progress of clinical trials, including levels of patient enrollment, invoices received and contracted costs when evaluating the adequacy of the amount expensed and the related prepaid asset and accrued liability. Significant judgments and estimates must be made and used in determining the accrued balance and expense in any accounting period. We review and accrue CRO expenses and clinical trial study expenses based on work performed and rely upon estimates of those costs applicable to the stage of completion of a study. Accrued CRO costs are subject to revisions as such trials progress to completion. Revisions are charged to expense in the period in which the facts that give rise to the revision become known. With respect to clinical site costs, the financial terms of these agreements are subject to negotiation and vary from contract to contract. Payments under these contracts may be uneven, and depend on factors such as the achievement of certain events, the successful recruitment of patients, the completion of portions of the clinical trial or similar conditions. The objective of our policy is to match the recording of expenses in our financial statements to the actual services received and efforts expended. As such, expense accruals related to clinical site costs are recognized based on our estimate of the degree of completion of the event or events specified in the specific clinical study or trial contract.

Prepaid research and development in our consolidated balance sheets includes, among other things, costs related to agreements with CRO’s, certain costs to third party service providers related to development and manufacturing services as well as clinical development. These agreements often require payments in advance of services performed or goods received. Accordingly, as of December 31, 2018 and December 31, 2017, we recorded approximately $9.7 million and $8.1 million, respectively, in prepaid research and development related to such advance agreements.

INCOME TAXES

Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases, operating losses and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in operations in the period that includes the enactment date. If the likelihood of realizing the deferred tax assets or liability is less than “more likely than not,” a valuation allowance is then created.

We, and our subsidiaries, file income tax returns in the U.S. Federal jurisdiction and in various states. We have tax net operating loss carryforwards that are subject to examination for a number of years beyond the year in which they were generated for tax purposes. Since a portion of these net operating loss carryforwards may be utilized in the future, many of these net operating loss carryforwards will remain subject to examination. We recognize interest and penalties related to uncertain income tax positions in income tax expense. Refer to Note 7 for further information for impact of tax reform.

STOCK-BASED COMPENSATION

We recognize all share-based payments to employees and non-employee directors (as compensation for service) as noncash compensation expense in the condensed consolidated financial statements based on the fair values of such payments. Stock-based compensation expense recognized each period is based on the value of the portion of share-based payment awards that is ultimately expected to vest during the period. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates.

For share-based payments to consultants and other third-parties (including related parties), noncash compensation expense is determined at the “measurement date.” The expense is recognized over the vesting period of the award. Until the measurement date is reached, the total amount of compensation expense remains uncertain. We record compensation expense based on the fair value of the award at the reporting date. The awards to consultants and other third-parties (including related parties) are then revalued, or the total compensation is recalculated based on the then current fair value, at each subsequent reporting date.

In addition, because some of the restricted stock issued to employees, consultants and other third-parties vest upon achievement of certain milestones, the total expense is uncertain. Compensation expense for such awards that vest upon the achievement of milestones is recognized when the achievement of such milestones becomes probable.

BASIC AND DILUTED NET LOSS PER COMMON SHARE

Basic net loss per share of our common stock is calculated by dividing net loss applicable to the common stock by the weighted-average number of our common stock outstanding for the period. Diluted net loss per share of common stock is the same as basic net loss per share of common stock since potentially dilutive securities from stock options, stock warrants and convertible preferred stock would have an antidilutive effect either because we incurred a net loss during the period presented or because such potentially dilutive securities were out of the money and the Company realized net income during the period presented. The amounts of potentially dilutive securities excluded from the calculation were 6,528,932, 4,835,706 and 8,033,779 at December 31, 2018, 2017 and 2016, respectively. During the years ended December 31, 2018, 2017 and 2016 the Company incurred a net loss, therefore, all of the securities are antidilutive and excluded from the computation of diluted loss per share.

	December 31,
	2018	2017	2016
Unvested restricted stock	4,595,689	4,820,143	7,142,055
Options	1,916,900	--	--
Shares issuable upon note conversion	16,343	15,563	14,812
Warrants	--	--	876,912
Total	6,528,932	4,835,706	8,033,779

LONG-LIVED ASSETS AND GOODWILL

Long-lived assets are reviewed for potential impairment when circumstances indicate that the carrying value of long-lived tangible and intangible assets with finite lives may not be recoverable. Management’s policy in determining whether an impairment indicator exists, a triggering event, comprises measurable operating performance criteria as well as qualitative measures. If an analysis is necessitated by the occurrence of a triggering event, we make certain assumptions in determining the impairment amount. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized.

Goodwill is reviewed for impairment annually, or earlier when events arise that could indicate that an impairment exists. We test for goodwill impairment using a two-step process. The first step compares the fair value of the reporting unit with the unit's carrying value, including goodwill. When the carrying value of the reporting unit is greater than fair value, the unit’s goodwill may be impaired, and the second step must be completed to measure the amount of the goodwill impairment charge, if any. In the second step, the implied fair value of the reporting unit’s goodwill is compared with the carrying amount of the unit’s goodwill. If the carrying amount is greater than the implied fair value, the carrying value of the goodwill must be written down to its implied fair value. We will continue to perform impairment tests annually, at December 31, and whenever events or changes in circumstances suggest that the carrying value of an asset may not be recoverable. There was no impairment to goodwill as of December 31, 2018.

CASH AND CASH EQUIVALENTS

12 Months Ended

Dec. 31, 2018

Cash and Cash Equivalents [Abstract]

CASH AND CASH EQUIVALENTS

The following tables summarize our cash and cash equivalents at December 31, 2018 and 2017:

(in thousands)	December 31, 2018		December 31, 2017

Checking and bank deposits	$	39,268	$	55,682
Money market funds		2,690		1,036
Total	$	41,958	$	56,718

INVESTMENT SECURITIES

12 Months Ended

Dec. 31, 2018

Investments, Debt and Equity Securities [Abstract]

INVESTMENT SECURITIES

Our investments as of December 31, 2018 and 2017 are classified as held-to-maturity. Held-to-maturity investments are recorded at amortized cost.

The following tables summarize our investment securities at December 31, 2018 and 2017:

(in thousands)	December 31, 2018
	Amortized cost, as adjusted		Gross unrealized holding gains		Gross unrealized holding losses		Estimated fair value
Short-term investments:
Obligations of domestic governmental agencies (maturing between January 2019 and November 2019) (held-to-maturity)	$	26,848	$	2	$	10	$	26,840
Total short-term investment securities	$	26,848	$	2	$	10	$	26,840

	December 31, 2017
	Amortized cost, as adjusted		Gross unrealized holding gains		Gross unrealized holding losses		Estimated fair value
Short-term investments:
Obligations of domestic governmental agencies (maturing between January 2018 and November 2018) (held-to-maturity)	$	27,999	$	--	$	35	$	27,964
Total short-term investment securities	$	27,999	$	--	$	35	$	27,964

FAIR VALUE MEASUREMENTS

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

FAIR VALUE MEASUREMENTS

We measure certain financial assets and liabilities at fair value on a recurring basis in the financial statements. The fair value hierarchy ranks the quality and reliability of inputs, or assumptions, used in the determination of fair value and requires financial assets and liabilities carried at fair value to be classified and disclosed in one of the following three categories:

● Level 1 – quoted prices in active markets for identical assets and liabilities;

● Level 2 – inputs other than Level 1 quoted prices that are directly or indirectly observable; and

● Level 3 – unobservable inputs that are not corroborated by market data.

As of December 31, 2018 and 2017, the fair values of cash and cash equivalents, restricted cash, and notes and interest payable approximate their carrying value.

At the time of our merger (we were then known as Manhattan Pharmaceuticals, Inc. (“Manhattan”)) with Ariston Pharmaceuticals, Inc. (“Ariston”) in March 2010, Ariston issued $15.5 million of five-year 5% notes payable (the “5% Notes”) in satisfaction of several note payable issuances. The 5% Notes and accrued and unpaid interest thereon are convertible at the option of the holder into common stock at the conversion price of $1,125 per share. Ariston agreed to make quarterly payments on the 5% Notes equal to 50% of the net product cash flow received from the exploitation or commercialization of Ariston’s product candidates, AST-726 and AST-915. We have no obligations under the 5% Notes aside from a) 50% of the net product cash flows from Ariston’s product candidates, if any, payable to noteholders; and b) the conversion feature, discussed above.

The cumulative liability including accrued and unpaid interest of the 5% Notes was approximately $18.4 million at December 31, 2018 and $17.5 million at December 31, 2017. No payments have been made on the 5% Notes as of December 31, 2018.

In December 2011, we elected the fair value option for valuing the 5% Notes. The fair value option was elected in order to reflect in our financial statements the assumptions that market participants use in evaluating these financial instruments.

As of December 31, 2013, as a result of expiring intellectual property rights and other factors, it was determined that net product cash flows from AST-726 were unlikely. As we have no other obligations under the 5% Notes aside from the net product cash flows and the conversion feature, the conversion feature was used to estimate the 5% Notes’ fair value as of December 31, 2018 and 2017. The assumptions, assessments and projections of future revenues are subject to uncertainties, difficult to predict, and require significant judgment. The use of different assumptions, applying different judgment to inherently subjective matters and changes in future market conditions could result in significantly different estimates of fair value and the differences could be material to our consolidated financial statements.

The following tables provide the fair value measurements of applicable financial liabilities as of December 31, 2018 and 2017:

(in thousands)	Financial liabilities at fair value as of December 31, 2018
	Level 1		Level 2		Level 3		Total

5% Notes	$	--	$	--	$	67	$	67
Total	$	--	$	--	$	67	$	67

	Financial liabilities at fair value as of December 31, 2017
	Level 1		Level 2		Level 3		Total

5% Notes	$	--	$	--	$	128	$	128
Total	$	--	$	--	$	128	$	128

The Level 3 amounts above represent the fair value of the 5% Notes and related accrued interest.

The following table summarizes the changes in Level 3 instruments for the years ended December 31, 2017 and 2018:

(in thousands)

Balance at January 1, 2017	$	69
Interest accrued on face value of 5% Notes		845
Conversion of 5% Notes		--
Change in fair value of Level 3 liabilities		(786	)
Balance at December 31, 2017		128
Interest accrued on face value of 5% Notes		878
Conversion of 5% Notes		--
Change in fair value of Level 3 liabilities		(939	)
Balance at December 31, 2018	$	67

The change in the fair value of the Level 3 liabilities is reported in other (income) expense in the accompanying consolidated statements of operations.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

STOCKHOLDERS' EQUITY

12 Months Ended

Dec. 31, 2018

Stockholders' Equity Note [Abstract]

STOCKHOLDERS' EQUITY

Preferred Stock

Our amended and restated certificate of incorporation authorizes the issuance of up to 10,000,000 shares of preferred stock, $0.001 par value, with rights senior to those of our common stock, issuable in one or more series. Upon issuance, the Company can determine the rights, preferences, privileges and restrictions thereof. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number of shares constituting any series or the designation of such series, any or all of which may be greater than the rights of common stock.

Stockholder Rights Plan

On July 18, 2014, we adopted a stockholder rights plan. The stockholder rights plan is embodied in the Stockholder Protection Rights Agreement dated as of July 18, 2014 (the "Rights Agreement"), between us and American Stock Transfer & Trust Company, LLC, as rights agent (the "Rights Agent").

Accordingly, the Board of Directors declared a distribution of one right (a “Right”) for each outstanding share of common stock, to stockholders of record at the close of business on July 28, 2014, for each share of common stock issued (including shares distributed from treasury) by us thereafter and prior to the Separation Time (as defined in the Rights Agreement), and for certain shares of common stock issued after the Separation Time. Following the Separation Time, each Right entitles the registered holder to purchase from us one one-thousandth (1/1,000) of a share of Series A Junior Participating Preferred Stock, par value $0.001 per share (the "Preferred Stock"), at a purchase price of $100.00 (the "Exercise Price"), subject to adjustment. The description and terms of the Rights are set forth in the Rights Agreement. Each one one-thousandth of a share of Preferred Stock has substantially the same rights as one share of common stock. Subject to the terms and conditions of the Rights Agreement, Rights become exercisable ten days after the public announcement that a “Person” has become an “Acquiring Person” (as each such term is defined in the Rights Agreement). Any Rights held by an Acquiring Person are void and may not be exercised.

If a Person becomes an Acquiring Person, all holders of Rights, except the Acquiring Person, may purchase at the Right’s then-current exercise price, common stock having a market value equal to twice the exercise price. Moreover, at any time after a Person becomes an Acquiring Person (unless such Person acquires 50 percent or more of our common stock then outstanding, as more fully described in the Rights Agreement), the Board of Directors may exchange all (but not less than all) of the then outstanding Rights (other than rights owned by such Person, which would have become void) for shares of common stock at an exchange ratio of one share of common stock per Right, appropriately adjusted in order to protect the interests of holders of Rights.

The Rights Agreement was approved by our Board of Directors on July 18, 2014. The Rights will expire at the close of business on its ten year anniversary, unless earlier exchanged or terminated by us.

Common Stock

Our amended and restated certificate of incorporation authorizes the issuance of up to 150,000,000 shares of $0.001 par value common stock.

In December 2014, we filed a shelf registration statement on Form S-3 (the "2015 S-3"), which was declared effective in January 2015. Under the 2015 S-3, the Company may sell up to a total of $250 million of its securities. In connection with the 2015 S-3, we amended our 2013 At-the-Market Issuance Sales Agreement with MLV & Co, LLC (“MLV”) (the "2015 ATM") such that we may issue and sell additional shares of our common stock, having an aggregate offering price of up to $175.0 million, from time to time through MLV and FBR Capital Markets & Co. ("FBR", each of MLV and FBR individually an "Agent" and collectively the "Agents"), acting as the sales agents. Under the 2015 ATM we pay the Agents a commission rate of up to 3.0% of the gross proceeds from the sale of any shares of common stock sold through the Agents.

During the year ended December 31, 2017, we sold a total of 3,104,253 shares of common stock under the 2015 ATM for aggregate total gross proceeds of approximately $31.6 million at an average selling price of $10.18 per share, resulting in net proceeds of approximately $31.0 million after deducting commissions and other transaction costs. During the year ended December 31, 2016, we sold a total of 570,366 shares of common stock under the 2015 ATM for aggregate total gross proceeds of approximately $4.5 million at an average selling price of $7.88 per share, resulting in net proceeds of approximately $4.4 million after deducting commissions and other transaction costs.

In March 2017, we completed an underwritten public offering of 5,128,206 shares of our common stock (plus a 30-day underwriter overallotment option to purchase up to an additional 769,230 shares of common stock, which was exercised) at a price of $9.75 per share. Net proceeds from this offering, including the overallotment option, were approximately $54 million, net of underwriting discounts and offering expenses of approximately $3.6 million.

In May 2017, we filed a shelf registration statement on Form S-3 (the "2017 S-3"), which was declared effective in June 2017, replacing the 2015 S-3. Under the 2017 S-3, the Company may sell up to a total of $300 million of its securities. In connection with the 2017 S-3, we entered into an At-the-Market Issuance Sales Agreement (the "2017 ATM") with Jefferies LLC, Cantor Fitzgerald & Co., FBR Capital Markets & Co., SunTrust Robinson Humphrey, Inc., Raymond James & Associates, Inc., Ladenburg Thalmann & Co. Inc. and H.C. Wainwright & Co., LLC (each a "2017 Agent" and collectively, the "2017 Agents"), relating to the sale of shares of our common stock. Under the 2017 ATM we pay the 2017 Agents a commission rate of up to 3.0% of the gross proceeds from the sale of any shares of common stock.

During the year ended December 31, 2017, we sold a total of 4,689,418 shares of common stock under the 2017 ATM for aggregate total gross proceeds of approximately $47.7 million at an average selling price of $10.18 per share, resulting in net proceeds of approximately $46.9 million after deducting commissions and other transactions costs.

During the year ended December 31, 2018, we sold a total of 9,025,222 shares of common stock under the 2017 ATM for aggregate total gross proceeds of approximately $115.8 million at an average selling price of $12.83 per share, resulting in net proceeds of approximately $113.7 million after deducting commissions and other transactions costs.

The 2017 S-3 is currently our only active shelf registration statement. After deducting shares already sold, there is approximately $136.5 million of common stock that remains available for sale under the 2017 S-3 at December 31, 2018. We may offer the securities under the 2017 S-3 from time to time in response to market conditions or other circumstances if we believe such a plan of financing is in the best interests of our stockholders. We believe that the 2017 S-3 provides us with the flexibility to raise additional capital to finance our operations as needed.

Treasury Stock

As of December 31, 2018 and 2017, 41,309 shares of common stock are being held in Treasury, at a cost of approximately $234,000, representing the fair market value on the date the shares were surrendered to the Company to satisfy employee tax obligations.

Equity Incentive Plans

The TG Therapeutics, Inc. Amended and Restated 2012 Incentive Plan (“2012 Incentive Plan”) was approved by stockholders in June 2018. Pursuant to this amendment, 6,000,000 shares were added to the 2012 Incentive Plan. As of December 31, 2018 and 2017, 1,916,900 and zero options, respectively, were outstanding and up to an additional 3,216,213 shares may be issued under the 2012 Incentive Plan.

Effective as of January 1, 2017, we entered into an amendment (the “Amendment”) to the employment agreement entered into as of December 15, 2011 (together with the Amendment, the “Employment Agreement”) with Michael S. Weiss, our Executive Chairman and Chief Executive Officer and President. Under the Amendment, Mr. Weiss will remain as Chief Executive Officer and President, removing the interim status. Simultaneously, we entered into a Strategic Advisory Agreement (the “Advisory Agreement”) with Caribe BioAdvisors, LLC (the “Advisor”) owned by Mr. Weiss to provide the services of Mr. Weiss as Chairman of the Board and as Executive Chairman. As part of the Amendment, Mr. Weiss also agreed to forfeit 3,381,866 restricted shares previously granted under the Employment Agreement that were predominantly subject to time-based vesting over the next three years. Simultaneously, (i) Mr. Weiss was issued 418,371 restricted shares under the Employment Agreement that vest in 2018 and 2019 and (ii) the Advisor was issued 2,960,000 restricted shares under the Advisory Agreement that vested on market capitalization thresholds ranging from $375 million to $750 million. In accordance with GAAP, there was no incremental stock compensation expense recognition as a result of the modification.

Stock Options

The estimated fair value of the options granted in the year ended December 31, 2018 was determined utilizing the Black-Scholes option-pricing model at the date of grant. The following table summarizes stock option activity for the years ended December 31, 2018 (there were no stock options granted during the years ended December 31, 2017 and 2016):

	Number of shares		Weighted- average exercise price		Weighted- average Contractual Term (in years)		Aggregate intrinsic value

Outstanding at December 31, 2017		--		--		--	$	--
Granted		1,916,900		6.50
Exercised		--		--
Forfeited		--		--
Expired		--		--
Outstanding at December 31, 2018		1,916,900		6.50		9.75		--

Exercisable at December 31, 2018		--		--		--	$	--

As of December 31, 2018, the stock options outstanding include options granted to both employees and non-employees which are both time-based and milestone-based that vest upon certain corporate milestones. Stock-based compensation will be recorded if and when a milestone occurs. No expense was recognized during the year ended December 31, 2018 for these stock options.

The fair value of the Company's option awards were estimated using the assumptions below:

	Year Ended December 31, 2018
Volatility		192.76-296.71
Expected term (in years)		5.0-6.25
Risk-free rate		2.49-2.56%
Expected dividend yield		--%

Restricted Stock

Certain employees, directors and consultants have been awarded restricted stock. The restricted stock vesting consists of milestone and time-based vesting. The following table summarizes restricted share activity for the years ended December 31, 2018, 2017 and 2016:

	Number of Shares			Weighted Average Grant Date Fair Value
Outstanding at January 1, 2016		7,359,915		$	7.83
Granted		1,924,639			4.99
Vested		(595,726	)		7.38
Forfeited		(46,773	)		10.34
Outstanding at December 31, 2016		8,642,055			7.20
Granted		1,836,511			6.40
Vested		(4,103,048	)		5.24
Forfeited		(53,875	)		8.47
Outstanding at December 31, 2017		6,321,643			7.17
Granted		1,562,211			13.07
Vested		(1,596,966	)		9.38
Forfeited		(191,196	)		8.13
Outstanding at December 31, 2018		6,095,692		$	8.07

Total compensation expense associated with restricted stock grants was $12.9 million, $15.9 million and $7.5 million during the years ended December 31, 2018, 2017 and 2016, respectively. As of December 31, 2018, there was approximately $7.6 million of total unrecognized compensation expense related to unvested time-based restricted stock, which is expected to be recognized over a weighted-average period of 1 year. This amount does not include, as of December 31, 2018, 1,128,011 shares of restricted stock outstanding which are milestone-based and vest upon certain corporate milestones; and 2,103,750 shares of restricted stock outstanding issued to non-employees. Milestone-based non cash compensation expense will be measured and recorded if and when a milestone becomes probable. The expense for non-employee shares is determined at the “measurement date.” The expense is recognized over the vesting period of the award. Until the measurement date is reached, the total amount of compensation expense remains uncertain. We record compensation expense based on the fair value of the award at the reporting date.

Warrants

The following table summarizes warrant activity for the years ended December 31, 2018, 2017 and 2016:

	Warrants			Weighted- average exercise price		Aggregate intrinsic value
Outstanding at January 1, 2016		1,186,749		$	2.37	$	11,341,452
Issued		--			--
Exercised		(273,370	)		2.26
Expired		--			2.25
Outstanding at December 31, 2016		913,379			2.41		1,961,403
Issued		--			--
Exercised		(887,585	)		2.41
Expired		(25,794	)		--
Outstanding at December 31, 2017		--		$	--	$	--

There was no warrant activity during the year ended December 31, 2018.

LONG-TERM LIABILITIES AND NOTES PAYABLE

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

LONG-TERM LIABILITIES AND NOTES PAYABLE

The following is a summary of notes payable and long term liabilities:

(in thousands)

	December 31, 2018						December 31, 2017
	Current portion, net		Non-current portion, net		Total		Current portion, net		Non-current portion, net		Total
Convertible 5% Notes Payable	$	67	$	--	$	67	$	128	$	--	$	128
Long term liabilities		--		18,350		18,350		128		--		128
Totals	$	67	$	18,350	$	18,417	$	128	$	--	$	128

Convertible 5% Notes Payable

The 5% Notes and accrued and unpaid interest thereon are convertible at the option of the holder into common stock at the conversion price of $1,125 per share. We have no obligation under the 5% Notes aside from (a) 50% of the net product cash flows from Ariston’s product candidates, if any, payable to noteholders; and (b) the conversion feature, discussed above. Interest accrues monthly, is added to principal on an annual basis, every March 8, and is payable at maturity, which was March 8, 2015 (see Note 4 for further details).

The cumulative liability including accrued and unpaid interest of these notes was approximately $18.4 million at December 31, 2018 and $17.5 million at December 31, 2017. No payments have been made on the 5% Notes as of December 31, 2018.

Long-Term Liabilities

In 2018, we entered into an agreement with a contract manufacturer for the clinical and potential commercial supply of one of our product candidates. As part of this agreement, the contract manufacturer has agreed to defer payment of certain costs and expenses under the agreement in exchange for the payment of an administrative fee. As of December 31, 2018, we have incurred costs related to this agreement of approximately $18.4 million, which includes both service fees and raw material costs. All costs incurred in 2018 are to be invoiced in 2019 and are due in 2020. We will incur an administrative fee of six percent (6%) per year starting from the date of invoice issuance. No payments have been made to the contract manufacturer as of December 31, 2018 and accordingly the entire amount has been classified as long-term liabilities included in our consolidated balance sheet.

INCOME TAXES

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

INCOME TAXES

We account for income taxes under the asset and liability method. Deferred tax assets and liabilities are determined based on differences between the financial reporting and tax basis of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. A valuation allowance is established when necessary to reduce deferred tax assets to the amount expected to be realized. In determining the need for a valuation allowance, management reviews both positive and negative evidence, including current and historical results of operations, future income projections and the overall prospects of our business. Based upon management's assessment of all available evidence, we believe that it is more-likely-than-not that the deferred tax assets will not be realizable, and therefore, a valuation allowance has been established. The valuation allowance for deferred tax assets was approximately $142,947,000 and $99,713,000 as of December 31, 2018 and 2017, respectively.

On December 22, 2017, H.R.1, commonly known as the Tax Cuts and Jobs Act (the “Act”) was signed into law. Among other things, the Act reduced our corporate federal tax rate from 34% to 21% effective January 1, 2018. As a result, we were required to re-measure, through income tax expense, our deferred tax assets and liabilities using the enacted rate at which we expect them to be recovered or settled. The re-measurement of our net deferred tax asset would have resulted in additional income tax expense of $51,767,584 as of December 31, 2017; however, with full valuation allowance in place, the expense was reversed through a corresponding adjustment to the valuation allowance, resulting in no impact on income tax expense.

As of December 31, 2018, we have U.S. net operating loss carryforwards (“NOLs”) of approximately $550,619,000 and research and development credit carryforwards (“R&D credits”) of approximately $15,217,000. For income tax purposes, these NOLs and R&D credits will expire in various amounts through 2037. NOLs generated after 2017 do not expire. The Tax Reform Act of 1986 contains provisions which limit the ability to utilize net operating loss carryforwards and R&D credit carryforwards in the case of certain events including significant changes in ownership interests. The Exchange Transaction with TG Bio may have resulted in a “change in ownership” as defined by IRC Section 382 of the Internal Revenue Code of 1986, as amended. Additionally, stock issuance activities may have resulted in a “change in ownership” as defined by IRC Section 382 of the Internal Revenue Code of 1986, as amended. Accordingly, a substantial portion of the Company’s NOLs above may be subject to annual limitations in reducing any future year’s taxable income, and a substantial portion of the R&D Credit carryforwards may be subject to annual limitations in reducing any future year’s tax.

The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities at December 31, 2018 and 2017 are presented below.

(in thousands)	2018			2017
Deferred tax assets (liabilities):
Net operating loss carryforwards	$	122,678		$	83,656
Research and development credits		15,217			10,491
Noncash compensation		4,394			4,934
Other		658			632
Deferred tax assets, excluding valuation allowance		142,947			99,713

Less valuation allowance		(142,947	)		(99,713	)
Net deferred tax assets	$	--		$	--

There was no current or deferred income tax expense for the years ended December 31, 2018, 2017 and 2016. Income tax expense differed from amounts computed by applying the US Federal income tax rate of 21% for the year ending December 31, 2018 and 34% for the years ending December 31, 2017 and 2016 to pretax loss as follows:

	For the year ended December 31,
(in thousands)	2018			2017			2016

Loss before income taxes, as reported in the consolidated statements of operations	$	(173,482	)	$	(118,476	)	$	(78,253	)

Computed “expected” tax benefit	$	(36,431	)	$	(40,282	)	$	(26,606	)

Increase (decrease) in income taxes resulting from:
Expected benefit from state and local taxes		(2,243	)		(1,106	)		(835	)
Research and development credits		(4,726	)		(3,697	)		(2,364	)
Other		639			1,563			(8	)
Stock awards		(473	)		8,213			--
Enactment of federal tax reform		--			51,768			--
Change in the balance of the valuation allowance for deferred tax assets		43,234			(16,459	)		29,813
	$	--		$	--		$	--

We file income tax returns in the U.S Federal and various state and local jurisdictions. With certain exceptions, the Company is no longer subject to U.S. Federal and state income tax examinations by tax authorities for years prior to 2015. However, NOLs and tax credits generated from those prior years could still be adjusted upon audit.

The Company would recognize interest and penalties, if any, related to uncertain tax position in income tax expense in the statement of operations. There was no accrual for interest and penalties related to uncertain tax positions for 2018. We do not believe that there will be a material change in our unrecognized tax positions over the next twelve months. All of the unrecognized tax benefits, if recognized, would be offset by the valuation allowance.

LICENSE AGREEMENTS

12 Months Ended

Dec. 31, 2018

License Agreement [Abstract]

LICENSE AGREEMENTS

BET

In May 2016, as part of a broader agreement with Jubilant Biosys (“Jubilant”), an India-based biotechnology company, we entered into a sub-license agreement (“JBET Agreement”) with Checkpoint Therapeutics, Inc. (“Checkpoint”) (see Note 9), for the development and commercialization of Jubilant’s novel BET inhibitor program in the field of hematological malignancies.

Under the terms of the agreement, we paid Checkpoint an up-front licensing fee of $1.0 million and will make additional payments contingent on certain preclinical, clinical, and regulatory milestones, including commercial milestones totaling up to approximately $177 million and a single-digit royalty on net sales. TG will also provide funding to support certain targeted research efforts at Jubilant.

TGR-1202 (Umbralisib)

On September 22, 2014, we exercised our option to license the global rights to umbralisib, thereby entering into an exclusive licensing agreement (the “TGR-1202 License”) with Rhizen Pharmaceuticals, SA (“Rhizen”) for the development and commercialization of umbralisib. Prior to this, we had been jointly developing umbralisib in a 50:50 joint venture with Rhizen.

Under the terms of the TGR-1202 License, Rhizen received a $4.0 million cash payment and 371,530 shares of our common stock as an upfront license fee. With respect to umbralisib, Rhizen will be eligible to receive regulatory filing, approval and sales-based milestone payments in the aggregate of approximately $175 million, a small portion of which will be payable on the first New Drug Application (NDA) filing and the remainder on approval in multiple jurisdictions for up to two oncology indications and one non-oncology indication and attaining certain sales milestones. In addition, if umbralisib is co-formulated with another drug to create a new product (a "New Product"), Rhizen will be eligible to receive similar regulatory approval and sales-based milestone payments for such New Product. Additionally, Rhizen will be entitled to tiered royalties on our future net sales of umbralisib and any New Product. In lieu of sales milestones and royalties on net sales, Rhizen shall also be eligible to participate in sublicensing revenue, if any, based on a percentage that decreases as a function of the number of patients treated in clinical trials following the exercise of the license option. Rhizen will retain global manufacturing rights to umbralisib, provided that they are price competitive with alternative manufacturers.

TG-1101 (Ublituximab)

In November 2012, we entered into an exclusive (within the territory) sublicense agreement with Ildong relating to the development and commercialization of ublituximab in South Korea and Southeast Asia. Under the terms of the sublicense agreement, Ildong has been granted a royalty bearing, exclusive right, including the right to grant sublicenses, to develop and commercialize ublituximab in South Korea, Taiwan, Singapore, Indonesia, Malaysia, Thailand, Philippines, Vietnam, and Myanmar.

An upfront payment of $2.0 million, which was received in December 2012, net of $0.3 million of income tax withholdings, is being recognized as license revenue on a straight-line basis over the life of the agreement, which is through the expiration of the last licensed patent right or 15 years after the first commercial sale of a product in such country, unless the agreement is earlier terminated, and represents the estimated period over which we will have certain ongoing responsibilities under the sublicense agreement. We recorded license revenue of approximately $152,000 for each of the years ended December 31, 2018, 2017 and 2016, and, at December 31, 2018, 2017 and 2016, have deferred revenue of approximately $1.1 million, $1.2 million and $1.4 million, respectively, associated with this $2 million payment (approximately $152,000 of which has been classified in current liabilities at December 31, 2018).

We may receive up to an additional $5.0 million in payments upon the achievement of pre-specified milestones. In addition, upon commercialization, Ildong will make royalty payments to us on net sales of ublituximab in the sublicense territory.

TG-1701: BTK

In January 2018, we entered into a global exclusive license agreement with Jiangsu Hengrui Medicine Co. (“Hengrui”), to acquire worldwide intellectual property rights, excluding Asia but including Japan, and for the research, development, manufacturing, and commercialization of products containing or comprising of any of Hengrui’s Bruton’s Tyrosine Kinase inhibitors containing the compounds of either TG-1701 (SHR1459 or EBI1459) or TG1702 (SHR1266 or EBI1266). Pursuant to the agreement, in April 2018, we paid Jiangsu an upfront fee of $1.0 million in our common stock recorded to non-cash stock expense associated with in-licensing agreements in our consolidated statement of operations. Jiangsu is eligible to receive milestone payments totaling approximately $350 million upon and subject to the achievement of certain milestones. Various provisions allow for payments in conjunction with the agreement to be made in cash or our common stock, while others limit the form of payment. Royalty payments in the low double digits are due on net sales of licensed products and revenue from sublicenses.

TG-1801: anti-CD47/anti-CD19

In June 2018, we entered into a Joint Venture and License Option Agreement with Novimmune SA (“Novimmune”) to collaborate on the development and commercialization of Novimmune’s novel first-in-class anti-CD47/anti-CD19 bispecific antibody known as TG-1801 (previously NI-1701). The companies will jointly develop the product on a worldwide basis, focusing on indications in the area of hematologic B-cell malignancies. We serve as the primary responsible party for the development, manufacturing and commercialization of the product. Pursuant to the agreement, in June 2018 we paid Novimmune an upfront payment of $3.0 million in our common stock recorded to non-cash stock expense associated with in-licensing agreements in our consolidated statement of operations. Further milestone payments will be paid based on early clinical development, and the Company will be responsible for the costs of clinical development of the product through the end of the Phase 2 clinical trials, after which the Company and Novimmune will be jointly responsible for all development and commercialization costs. The Company and Novimmune will each maintain an exclusive option, exercisable at specific times during development, for the Company to license the rights to TG-1801, in which case Novimmune is eligible to receive additional milestone payments totaling approximately $185 million as well as tiered royalties on net sales in the high single to low double digits upon and subject to the achievement of certain milestones.

RELATED PARTY TRANSACTIONS

12 Months Ended

Dec. 31, 2018

RELATED PARTY TRANSACTIONS

LFB Biotechnologies

On January 30, 2012, we entered into an exclusive license agreement with LFB Biotechnologies, GTC Biotherapeutics and LFB/GTC LLC, all wholly-owned subsidiaries of LFB Group, relating to the development of ublituximab (the “LFB License Agreement”). In connection with the LFB License Agreement, LFB Group was issued 5,000,000 shares of common stock, and a warrant to purchase 2,500,000 shares of common stock at a purchase price of $0.001 per share. In addition, LFB Group maintained the right to nominate a board member until such time as LFB Group owns less than 10% of the outstanding common stock. As of April 2018, LFB no longer has the right to nominate a board member as LFB’s ownership had fallen below 10% of the outstanding shares of the Company’s Common Stock.

Under the terms of the LFB License Agreement, we utilize LFB Group for certain development and manufacturing services. We incurred approximately $0.2 million, $2.3 million and $8.1 million in expenses for such services during the years ended December 31, 2018, 2017 and 2016, respectively, which have been included in other research and development expenses in the accompanying consolidated statements of operations.

Other Parties

In October 2014, we entered into an agreement (the “Office Agreement”) with FBIO to occupy approximately 45% (which shall be adjusted based on utilization as discussed below) of the 24,000 square feet of New York City office space leased by FBIO, which is now our corporate headquarters. The Office Agreement requires us to pay our respective share of the average annual rent and other costs of the 15-year lease. We approximate an average annual rental obligation of $1.1 million under the Office Agreement. We began to occupy this new space in April 2016, with rental payments beginning in the third quarter of 2016. During the years ended December 31, 2018 and 2017, we recorded rent expense of approximately $1.3 million and $1.2 million, and at December 31, 2018, have deferred rent of approximately $1.5 million. Mr. Weiss, our Executive Chairman and Chief Executive Officer, is also Executive Vice Chairman of FBIO.

During the year ended December 31, 2018, we paid FBIO $0.1 million for our portion of the build-out costs (as required under the Desk Agreement), which have been allocated to us at the 45% rate mentioned above. The allocated build-out costs have been recorded in Leasehold Interest, net on the Company’s consolidated balance sheets and will be amortized over the 15-year term of the Office Agreement. After an initial commitment period of the 45% rate for a period of three (3) years, we and FBIO will determine actual office space utilization annually and if our utilization differs from the amount we have been billed, we will either receive credits or be assessed incremental utilization charges. Also in connection with this lease, in October 2014 we pledged $0.6 million to secure a line of credit as a security deposit for the Office Agreement, which has been recorded as restricted cash in the accompanying consolidated balance sheets. Additional collateral of $0.6 million was pledged in April 2018 to increase the letter of credit for the office space.

In July 2015, we entered into a Shared Services Agreement (the “Shared Services Agreement”) with FBIO to share the cost of certain services such as facilities use, personnel costs and other overhead and administrative costs. This Shared Services Agreement requires us to pay our respective share of services utilized. In connection with the Shared Services Agreement, we incurred expenses of approximately $1.6 million, $1.2 million and $0.8 million for shared services for the years ended December 31, 2018, 2017 and 2016, primarily related to shared personnel.

In May 2016, as part of a broader agreement with Jubilant, an India-based biotechnology company, we entered into a sublicense agreement with Checkpoint, a subsidiary of FBIO, for the development and commercialization of Jubilant’s novel BET inhibitor program in the field of hematological malignancies. We paid Checkpoint an up-front licensing fee of $1.0 million in July 2016 and incurred expenses of $0.2 million in March 2017 for the first milestone achievement as part of the JBET Agreement which is recorded in other research and development in the accompanying consolidated statement of operations.

In March 2015, we entered into a Global Collaboration Agreement (“Collaboration Agreement”) with Checkpoint for the development and commercialization of anti-PD-L1 and anti-GITR antibody research programs in the field of hematological malignancies. We incurred expenses of approximately $0.6 million for the year ended December 31, 2018 related mainly to manufacturing costs of PD-L1, while no costs were incurred during the years ended December 31, 2017 and 2016. The relevant expenses are recorded in other research and development in the accompanying consolidated statement of operations.

COMMITMENTS AND CONTINGENCIES

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

COMMITMENTS AND CONTINGENCIES

As of December 31, 2018, we have known contractual obligations; commitments and contingencies of $35.4 million related to our long term liabilities and operating lease obligations.

Payment due by period (in thousands)
	Total		Less than 1 year		1-3 years		3-5 years		More than 5 years
Contractual obligations
Operating leases	$	16,996	$	1,362	$	2,701	$	2,742	$	10,191
Contract manufacturer		18,350		--		18,350		--		--
Total	$	35,346	$	1,362	$	21,051	$	2,742	$	10,191

Contract Manufacturer

See Note 6 for a detailed description of our long term liabilities. Future minimum contractual commitments as of December 31, 2018 total approximately $18.4 million and are due in 2020.

Leases

See Note 9 for a detailed description of our lease arrangement in New York. Total rental expense was approximately $1.4 million, $1.4 million and $1.6 million for the years ended December 31, 2018, 2017, and 2016, respectively.

Future minimum lease commitments as of December 31, 2018, in the aggregate total approximately $17.0 million through December 31, 2031. The preceding table shows future minimum lease commitments, which include our office leases in New York, North Carolina and Tennessee by year as of December 31, 2018.

QUARTERLY FINANCIAL INFORMATION

12 Months Ended

Dec. 31, 2018

Disclosure Text Block [Abstract]

QUARTERLY FINANCIAL INFORMATION

(in thousands)	3 Months Ended
	March 31, 2018			June 30, 2018			September 30, 2018			December 31, 2018

License revenue	$	38		$	38		$	38		$	38

Total costs and expenses		40,615			44,383			34,366			54,188

Net loss	$	(41,529	)	$	(44,142	)	$	(33,951	)	$	(53,861	)

Basic and diluted net loss per common share	$	(0.59	)	$	(0.59	)	$	(0.43	)	$	(0.68	)

(in thousands)	3 Months Ended
	March 31, 2017			June 30, 2017			September 30, 2017			December 31, 2017

License revenue	$	38		$	38		$	38		$	38

Total costs and expenses		27,704			28,463			31,623			31,073

Net loss	$	(27,727	)	$	(28,353	)	$	(31,536	)	$	(30,860	)

Basic and diluted net loss per common share	$	(0.52	)	$	(0.45	)	$	(0.48	)	$	(0.46	)

LITIGATION

12 Months Ended

Dec. 31, 2018

Litigation

LITIGATION

In October 2018, a purported securities class action complaint was filed in the U.S. District Court for the Southern District of New York (the “Southern District”) against the Company and one of its officers on behalf of all shareholders who purchased or otherwise acquired TG Therapeutics common stock between June 4, 2018 and September 25, 2018 (the “Class Period”). The case is captioned Randall Reinmann v. TG Therapeutics Inc., and Michael S. Weiss, Case No. 1:18-cv-09104-KPF. The complaint alleges that, throughout the Class Period, the Company made false and/or misleading statements and/or failed to disclose various facts and circumstances regarding its UNITY-CLL study allegedly in violation of the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder. In December 2018, the Southern District appointed Co-Lead Plaintiffs to represent the putative class, and approved their selection of Lead Counsel. On March 1, 2019, Co-Lead Plaintiffs filed a notice with the Southern District seeking to voluntarily dismiss the action in its entirety without prejudice.

In addition, on December 18, 2018, a related shareholder derivative litigation was filed in the Southern District against the Company’s directors and one of its officers in litigation captioned Thessalus Capital v. Weiss, et al., 1:18-cv-11918-KPF. The Company is named only as a nominal defendant. The suit alleges that the officer and directors breached their fiduciary duties to the Company, wasted corporate assets, and violated the Securities Exchange Act of 1934 and Rule 10b-5 promulgated thereunder in connection with the Company’s alleged failure to disclose various facts and circumstances regarding its UNITY-CLL study. The plaintiff asserts that the alleged disclosure violations concerning the Company’s UNITY-CLL study have caused the Company to incur losses, including defense costs, and further alleges that the named officer and directors received excessive compensation.

No legal reserve is necessary.

SUBSEQUENT EVENTS

12 Months Ended

Dec. 31, 2018

Subsequent Events [Abstract]

SUBSEQUENT EVENTS

On February 28, 2019 (the “Closing Date”), the Company (“Borrower”) entered into a term loan facility of up to $60.0 million (“Term Loan”) with Hercules Capital, Inc., (“Hercules”), the proceeds of which will be used for its ongoing research and development programs and for general corporate purposes. The Term Loan is governed by a loan and security agreement, dated February 28, 2019 (the “Loan Agreement”), which provides for up to four separate advances. The first advance of $30.0 million was drawn on the Closing Date. Two additional advances of $10.0 million may be drawn at the Borrower’s option but subject to the clinical trial milestones, and the fourth advance of $10.0 million, available in minimum increments of $5.0 million, is available through December 15, 2020 subject to the approval of Hercules’ investment committee.

The Term Loan will mature on March 1, 2022 (the “Loan Maturity Date”). Each advance accrues interest at a per annum rate of interest equal to the greater of either (i) the “prime rate” as reported in The Wall Street Journal plus 4.75%, and (ii) 10.25%. The Term Loan provides for interest-only payments until October 1, 2020. The interest-only period may be extended to April 1, 2021 if the Borrower, on or before September 30, 2020, achieves either the third milestone or the Company has raised at least an amount equal to $150.0 million in unrestricted net cash proceeds from one or more equity financings, subordinated indebtedness and/or upfront proceeds from business development transactions permitted under theLoan Agreement, in each case after February 7, 2019, and prior to September 30, 2020. Thereafter, amortization payments will be payable monthly in eighteen installments (or, if the period requiring interest-only payments has been extended to April 1, 2021, in twelve installments) of principal and interest (subject to recalculation upon a change in prime rates). At its option upon seven business days’ prior written notice to Hercules, the Company may prepay all or any portion greater than or equal to $5.0 million of the outstanding advances by paying the entire principal balance (or portion thereof), all accrued and unpaid interest, subject to a prepayment charge of 3.0%, if such advance is prepaid in any of the first twelve months following the Closing Date, 1.5%, if such advance is prepaid after twelve months following the Closing Date but on or prior to twenty-four months following the Closing Date, and 0% thereafter. In addition, a final payment equal to 3.5% of the aggregate principal amount of the loan extended by Hercules is due on the maturity date. Amounts outstanding during an event of default shall be payable on demand and shall accrue interest at an additional rate of 4.0% per annum of the past due amount outstanding.

The Term Loan is secured by a lien on substantially all of the assets of the Borrower, other than intellectual property and contains customary covenants and representations, including a liquidity covenant, financial reporting covenant and limitations on dividends, indebtedness, collateral, investments, distributions, transfers, mergers or acquisitions, taxes, corporate changes, deposit accounts, and subsidiaries.

The events of default under the Loan Agreement include, without limitation, and subject to customary grace periods, (1) the Borrower’s failure to make any payments of principal or interest under the Loan Agreement, promissory notes or other loan documents, (2) the Borrower’s breach or default in the performance of any covenant under the Loan Agreement, (3) the occurrence of a material adverse effect, (4) the Borrower making a false or misleading representation or warranty in any material respect, (5) the Borrower’s insolvency or bankruptcy, (6) certain attachments or judgments on the Borrower’s assets, or (7) the occurrence of any material default under certain agreements or obligations of the Borrower involving indebtedness in excess of $750,000. If an event of default occurs, Hercules is entitled to take enforcement action, including acceleration of amounts due under the Loan Agreement.

The Loan Agreement also contains warrant coverage of 2% of the total amount funded. A warrant (the “Warrant) was issued by Borrower to Hercules to purchase 147,058 shares of common stock with an exercise price of $4.08. The Warrant shall be exercisable for seven years from the date of issuance. Hercules may exercise the Warrant either by (a) cash or check or (b) through a net issuance conversion. The shares will be registered and freely tradeable within six months of issuance.

Additionally, on March 1, 2019, we announced the pricing of a public offering of 4,100,000 shares of our common stock (plus a 30-day underwriter overallotment option to purchase up to an additional 615,000 shares of common stock), with expected gross proceeds to the Company of $25.2 million, less underwriting discounts and commissions. The shares were sold under a shelf registration statement Form S-3 (File No. 333-218293) that was previously filed and declared effective by the SEC in June 2017. The offering is expected to close on March 5, 2019.

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

12 Months Ended

Dec. 31, 2018

Accounting Policies [Abstract]

Description of Business

Liquidity and Capital Resources

Our common stock is quoted on the Nasdaq Capital Market and trades under the symbol “TGTX.”

Recently Issued Accounting Standards

●

●	The vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before the original award is modified.

●	The classification of the modified award as an equity instrument or a liability instrument is the same as the classification of the original award immediately before the original award is modified.

Use of Estimates

Cash and Cash Equivalents

We treat liquid investments with original maturities of less than three months when purchased as cash and cash equivalents.

Cash and Cash Equivalents, Restricted Cash and Cash Equivalents

Investment Securities

Credit Risk

Revenue Recognition

●	Step 1: Identify the contract with the customer

●	Step 2: Identify the performance obligations in the contract

●	Step 3: Determine the transaction price

●	Step 4: Allocate the transaction price to the performance obligations in the contract

●	Step 5: Recognize revenue when the company satisfies a performance obligation

●	The customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (i.e., the good or service is capable of being distinct).

●	The entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (i.e., the promise to transfer the good or service is distinct within the context of the contract).

If a good or service is not distinct, the good or service is combined with other promised goods or services until a bundle of goods or services is identified that is distinct.

Research and Development Costs

Income Taxes

Stock-Based Compensation

Basic and Diluted Net Loss Per Share Common Share

	December 31,
	2018	2017	2016
Unvested restricted stock	4,595,689	4,820,143	7,142,055
Options	1,916,900	--	--
Shares issuable upon note conversion	16,343	15,563	14,812
Warrants	--	--	876,912
Total	6,528,932	4,835,706	8,033,779

Long-Lived Assets and Goodwill

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2018

Organization And Summary Of Significant Accounting Policies

Dilutive securities excluded from computation

	December 31,
	2018	2017	2016
Unvested restricted stock	4,595,689	4,820,143	7,142,055
Options	1,916,900	--	--
Shares issuable upon note conversion	16,343	15,563	14,812
Warrants	--	--	876,912
Total	6,528,932	4,835,706	8,033,779

CASH AND CASH EQUIVALENTS (Tables)

12 Months Ended

Dec. 31, 2018

Cash and Cash Equivalents [Abstract]

Schedule of Cash and Cash Equivalents

(in thousands)	December 31, 2018		December 31, 2017

Checking and bank deposits	$	39,268	$	55,682
Money market funds		2,690		1,036
Total	$	41,958	$	56,718

INVESTMENT SECURITIES (Tables)

12 Months Ended

Dec. 31, 2018

Investments, Debt and Equity Securities [Abstract]

Held-to-maturity Securities

(in thousands)	December 31, 2018
	Amortized cost, as adjusted		Gross unrealized holding gains		Gross unrealized holding losses		Estimated fair value
Short-term investments:
Obligations of domestic governmental agencies (maturing between January 2019 and November 2019) (held-to-maturity)	$	26,848	$	2	$	10	$	26,840
Total short-term investment securities	$	26,848	$	2	$	10	$	26,840

	December 31, 2017
	Amortized cost, as adjusted		Gross unrealized holding gains		Gross unrealized holding losses		Estimated fair value
Short-term investments:
Obligations of domestic governmental agencies (maturing between January 2018 and November 2018) (held-to-maturity)	$	27,999	$	--	$	35	$	27,964
Total short-term investment securities	$	27,999	$	--	$	35	$	27,964

FAIR VALUE MEASUREMENTS (Tables)

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value, Liabilities Measured on Recurring and Nonrecurring Basis

(in thousands)	Financial liabilities at fair value as of December 31, 2018
	Level 1		Level 2		Level 3		Total

5% Notes	$	--	$	--	$	67	$	67
Total	$	--	$	--	$	67	$	67

	Financial liabilities at fair value as of December 31, 2017
	Level 1		Level 2		Level 3		Total

5% Notes	$	--	$	--	$	128	$	128
Total	$	--	$	--	$	128	$	128

Change In Level Three Fair Value During Period

Balance at January 1, 2017	$	69
Interest accrued on face value of 5% Notes		845
Conversion of 5% Notes		--
Change in fair value of Level 3 liabilities		(786	)
Balance at December 31, 2017		128
Interest accrued on face value of 5% Notes		878
Conversion of 5% Notes		--
Change in fair value of Level 3 liabilities		(939	)
Balance at December 31, 2018	$	67

STOCKHOLDERS' EQUITY (Tables)

12 Months Ended

Dec. 31, 2018

Stockholders' Equity Note [Abstract]

Schedule of Share-based Compensation, Stock Options, Activity

	Number of shares		Weighted- average exercise price		Weighted- average Contractual Term (in years)		Aggregate intrinsic value

Outstanding at December 31, 2017		--		--		--	$	--
Granted		1,916,900		6.50
Exercised		--		--
Forfeited		--		--
Expired		--		--
Outstanding at December 31, 2018		1,916,900		6.50		9.75		--

Exercisable at December 31, 2018		--		--		--	$	--

Schedule of Nonvested Restricted Stock Units Activity

	Number of Shares			Weighted Average Grant Date Fair Value
Outstanding at January 1, 2016		7,359,915		$	7.83
Granted		1,924,639			4.99
Vested		(595,726	)		7.38
Forfeited		(46,773	)		10.34
Outstanding at December 31, 2016		8,642,055			7.20
Granted		1,836,511			6.40
Vested		(4,103,048	)		5.24
Forfeited		(53,875	)		8.47
Outstanding at December 31, 2017		6,321,643			7.17
Granted		1,562,211			13.07
Vested		(1,596,966	)		9.38
Forfeited		(191,196	)		8.13
Outstanding at December 31, 2018		6,095,692		$	8.07

Schedule Of Warrants Activity

	Warrants			Weighted- average exercise price		Aggregate intrinsic value
Outstanding at January 1, 2016		1,186,749		$	2.37	$	11,341,452
Issued		--			--
Exercised		(273,370	)		2.26
Expired		--			2.25
Outstanding at December 31, 2016		913,379			2.41		1,961,403
Issued		--			--
Exercised		(887,585	)		2.41
Expired		(25,794	)		--
Outstanding at December 31, 2017		--		$	--	$	--

LONG-TERM LIABILITIES AND NOTES PAYABLE (Tables)

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Schedule of Debt

	December 31, 2018						December 31, 2017
	Current portion, net		Non-current portion, net		Total		Current portion, net		Non-current portion, net		Total
Convertible 5% Notes Payable	$	67	$	--	$	67	$	128	$	--	$	128
Long term liabilities		--		18,350		18,350		128		--		128
Totals	$	67	$	18,350	$	18,417	$	128	$	--	$	128

INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of Deferred Tax Assets and Liabilities

(in thousands)	2018			2017
Deferred tax assets (liabilities):
Net operating loss carryforwards	$	122,678		$	83,656
Research and development credits		15,217			10,491
Noncash compensation		4,394			4,934
Other		658			632
Deferred tax assets, excluding valuation allowance		142,947			99,713

Less valuation allowance		(142,947	)		(99,713	)
Net deferred tax assets	$	--		$	--

Schedule of Effective Income Tax Rate Reconciliation

	For the year ended December 31,
(in thousands)	2018			2017			2016

Loss before income taxes, as reported in the consolidated statements of operations	$	(173,482	)	$	(118,476	)	$	(78,253	)

Computed “expected” tax benefit	$	(36,431	)	$	(40,282	)	$	(26,606	)

Increase (decrease) in income taxes resulting from:
Expected benefit from state and local taxes		(2,243	)		(1,106	)		(835	)
Research and development credits		(4,726	)		(3,697	)		(2,364	)
Other		639			1,563			(8	)
Stock awards		(473	)		8,213			--
Enactment of federal tax reform		--			51,768			--
Change in the balance of the valuation allowance for deferred tax assets		43,234			(16,459	)		29,813
	$	--		$	--		$	--

COMMITMENTS AND CONTINGENCIES (Tables)

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Schedule of Loss Contingencies by Contingency

Payment due by period (in thousands)
	Total		Less than 1 year		1-3 years		3-5 years		More than 5 years
Contractual obligations
Operating leases	$	16,996	$	1,362	$	2,701	$	2,742	$	10,191
Contract manufacturer		18,350		--		18,350		--		--
Total	$	35,346	$	1,362	$	21,051	$	2,742	$	10,191

- Definition

Tabular disclosure of the loss contingencies that were reported in the period or disclosed as of the balance sheet date.

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-SubTopic 20
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14557-108349

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12053-110248

+ Details

QUARTERLY FINANCIAL INFORMATION (Tables)

12 Months Ended

Dec. 31, 2018

Table Text Block Supplement [Abstract]

Schedule of Quarterly Financial Information

(in thousands)	3 Months Ended
	March 31, 2018			June 30, 2018			September 30, 2018			December 31, 2018

License revenue	$	38		$	38		$	38		$	38

Total costs and expenses		40,615			44,383			34,366			54,188

Net loss	$	(41,529	)	$	(44,142	)	$	(33,951	)	$	(53,861	)

Basic and diluted net loss per common share	$	(0.59	)	$	(0.59	)	$	(0.43	)	$	(0.68	)

(in thousands)	3 Months Ended
	March 31, 2017			June 30, 2017			September 30, 2017			December 31, 2017

License revenue	$	38		$	38		$	38		$	38

Total costs and expenses		27,704			28,463			31,623			31,073

Net loss	$	(27,727	)	$	(28,353	)	$	(31,536	)	$	(30,860	)

Basic and diluted net loss per common share	$	(0.52	)	$	(0.45	)	$	(0.48	)	$	(0.46	)

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Antidilutive securities excluded from computation of diluted loss per share	6,528,932	4,835,706	8,033,779
Restricted Stock [Member]
Antidilutive securities excluded from computation of diluted loss per share	4,595,689	4,820,143	7,142,055
Options [Member]
Antidilutive securities excluded from computation of diluted loss per share	1,916,900	0	0
Shares Upon Note Conversion [Member]
Antidilutive securities excluded from computation of diluted loss per share	16,343	15,563	14,812
Warrants [Member]
Antidilutive securities excluded from computation of diluted loss per share	0	0	876,912

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details Narrative) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Accumulated deficit	$ (528,345)	$ (354,863)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	6,528,932	4,835,706	8,033,779
Restricted Cash and Investments	$ 600	$ 600
Prepaid Manufacturing	$ 9,700	$ 8,100

CASH AND CASH EQUIVALENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash and Cash Equivalents [Abstract]
Checking and bank deposits	$ 39,268	$ 55,682
Money market funds	2,690	1,036
Total	$ 41,958	$ 56,718	$ 25,031

INVESTMENT SECURITIES (Details) - USD ($) $ in Thousands	12 Months Ended
INVESTMENT SECURITIES (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Amortized cost, as adjusted	$ 26,848	$ 27,999
Gross unrealized holding gains	2	0
Gross unrealized holding losses	10	35
Estimated fair value	26,840	27,964
Short-term Investments [Member] \| US Government Agencies Debt Securities [Member]
Amortized cost, as adjusted	26,848	27,999
Gross unrealized holding gains	2	0
Gross unrealized holding losses	10	35
Estimated fair value	$ 26,840	$ 27,964

FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
5% Notes	$ 67	$ 128
Totals	67	128
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
5% Notes	0	0
Totals	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
5% Notes	0	0
Totals	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
5% Notes	67	128
Totals	$ 67	$ 128

FAIR VALUE MEASUREMENTS (Details 1) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Balance at January	$ 128	$ 69
Interest accrued on face value of 5% Notes	878	845
Conversion of 5% Notes	0	0
Change in fair value of Level 3 liabilities	(939)	(786)
Balance at December	$ 67	$ 128

FAIR VALUE MEASUREMENTS (Details Narrative) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2010	Dec. 31, 2018	Dec. 31, 2017
Fair Value Measurement [Line Items]
Cumulative Liability		$ 18,400	$ 17,500
Manhattan and Ariston Pharmaceuticals Merger [Member]
Fair Value Measurement [Line Items]
Notes Issued	$ 15,500
Debt Instrument, Convertible, Conversion Price	$ 1,125
Percentage Of Cash Proceeds From Operation To Repay Convertible Debt	50.00%
Debt Instrument, Term	5 years
Debt Instrument, Interest Rate During Period	5.00%
Convertible Notes Payable [Member]
Fair Value Measurement [Line Items]
Cumulative Liability			$ 17,500
Debt Instrument, Convertible, Conversion Price		$ 1,125	$ 1,125
Debt Instrument, Interest Rate During Period			5.00%

STOCKHOLDERS' EQUITY (Details) - Employee Stock Option [Member] $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) $ / shares shares
Equity Incentive Plans Stock Option Activity [Line Items]
Number of shares, Outstanding Beginning Balance \| shares	0
Number of shares, Granted \| shares	1,916,900
Number of shares, Exercised \| shares	0
Number of shares, Forfeited \| shares	0
Number of shares, Expired \| shares	0
Number of shares, Outstanding Ending Balance \| shares	1,916,900
Number of shares, Exercisable at December 31 \| shares	0
Weighted - average exercise price, Outstanding Beginning Balance \| $ / shares	$ 0.00
Weighted - average exercise price, Granted \| $ / shares	6.50
Weighted - average exercise price, Exercised \| $ / shares	0.00
Weighted - average exercise price, Forfeited \| $ / shares	0.00
Weighted - average exercise price, Expired \| $ / shares	0.00
Weighted - average exercise price, Outstanding Ending Balance \| $ / shares	6.50
Weighted - average exercise price, Exercisable at December 31 \| $ / shares	$ 0.00
Weighted - average Contractual Term (in years)	0 years
Weighted - average Contractual Term, Exercisable at December 31 (in years)	9 years 9 months
Aggregate Intrinsic Value, Exercisable at December 31 \| $	$ 0

STOCKHOLDERS' EQUITY (Details 1) - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity Incentive Plans Restricted Stock Activity [Line Items]
Number of Shares, Outstanding at Begining Balance	6,321,643	8,642,055	7,359,915
Number of Shares, Granted	1,562,211	1,836,511	1,924,639
Number of Shares, Vested	(1,596,966)	(4,103,048)	(595,726)
Number of Shares, Forfeited	(191,196)	(53,875)	(46,773)
Number of Shares, Outstanding at Ending Balance	6,095,692	6,321,643	8,642,055
Weighted Average Grant Date Fair Value, Outstanding at Begining Balance	$ 7.17	$ 7.20	$ 7.83
Weighted Average Grant Date Fair Value, Granted	13.07	6.40	4.99
Weighted Average Grant Date Fair Value, Vested	9.38	5.24	7.38
Weighted Average Grant Date Fair Value, Forfeited	8.13	8.47	10.34
Weighted Average Grant Date Fair Value, Outstanding at Ending Balance	$ 8.07	$ 7.17	$ 7.20

STOCKHOLDERS' EQUITY (Details 2) - USD ($)	12 Months Ended
STOCKHOLDERS' EQUITY (Details 2) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Warrants, Outstanding at Beginning Balance	913,379	1,186,749
Warrants, Issued	0	0
Warrants, Exercised	(887,585)	(273,370)
Warrants, Expired	(25,794)	0
Warrants, Outstanding at Ending Balance	0	913,379
Weighted - average exercise price of Warrants, Outstanding at Beginning Balance	$ 2.41	$ 2.37
Weighted - average exercise price of Warrants, Issued	0.00	0.00
Weighted - average exercise price of Warrants, Exercised	2.41	2.26
Weighted - average exercise price of Warrants, Expired	0.00	2.25
Weighted - average exercise price of Warrants, Outstanding at Ending Balance	$ 0.00	$ 2.41
Aggregate Intrinsic Value of Warrants, Outstanding at Beginning Balance	$ 1,961,403	$ 11,341,452
Aggregate Intrinsic Value of Warrants, Outstanding at Ending Balance	$ 0	$ 1,961,403

STOCKHOLDERS' EQUITY (Details Narrative) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Preferred stock, shares authorized	10,000,000	10,000,000	10,000,000
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001	$ 0.001
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001	$ 0.001
Net Proceeds From Shares New Issues Over-Allotments	$ 113,639	$ 131,516	$ 4,411
Common Stock, Shares Authorized	150,000,000	150,000,000	150,000,000
Share-based Compensation, Total	$ 12,900	$ 15,900	$ 7,500
Treasury Stock, Shares	41,309	41,309	41,309
Treasury Stock, Value	$ 234	$ 234	$ 234
Atm [Member]
Stock Issued During Period, Shares, New Issues	9,025,222	3,104,253	570,366
Share Price	$ 12.83	$ 10.18	$ 7.88
Gross proceeds		$ 31,600	$ 4,400
Net proceeds		$ 31,000	$ 4,500

LONG-TERM LIABILITIES AND NOTES PAYABLE (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Notes Payable [Line Items]
Notes payable, Current portion, net	$ 67	$ 128
Notes payable, Non-current portion, net	18,350	0
Total	18,417	128
Convertible Notes [Member]
Notes Payable [Line Items]
Notes payable, Current portion, net	67	128
Notes payable, Non-current portion, net	0	0
Total	67	128
Long Term Liabilities [Member]
Notes Payable [Line Items]
Notes payable, Current portion, net	0	128
Notes payable, Non-current portion, net	18,350	0
Total	$ 18,350	$ 128

LONG-TERM LIABILITIES AND NOTES PAYABLE (Details Narrative) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Notes Payable [Line Items]
Cumulative Liability	$ 18,400	$ 17,500
Convertible Notes Payable [Member]
Notes Payable [Line Items]
Debt Instrument, Convertible, Conversion Price	$ 1,125	$ 1,125
Debt Instrument, Interest Rate During Period		5.00%
Cumulative Liability		$ 17,500

INCOME TAXES (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets (liabilities):
Net operating loss carryforwards	$ 122,678	$ 83,656
Research and development credit	15,217	10,491
Noncash compensation	4,394	4,934
Other	658	632
Deferred tax asset, excluding valuation allowance	142,947	99,713
Less valuation allowance	(142,947)	(99,713)
Net deferred tax assets	$ 0	$ 0

INCOME TAXES (Details 1) - USD ($) $ in Thousands	12 Months Ended
INCOME TAXES (Details 1) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Loss before income taxes, as reported in the consolidated statements of operations	$ (173,482)	$ (118,476)	$ (78,253)
Computed "expected" tax benefit	(36,431)	(40,282)	(26,606)
Increase (decrease) in income taxes resulting from:
Expected benefit from state and local taxes	(2,243)	(1,106)	(835)
Research and development credits	(4,726)	(3,697)	(2,364)
Other	639	1,563	(8)
Impact of change in state tax rates on deferred taxes	(473)	8,213	0
Stock awards	0	51,768	0
Effects of federal tax reform rate changes	43,234	(16,459)	29,813
Change in the balance of the valuation allowance for deferred tax assets	0	0	0
Income Tax Expense (Benefit)	$ 0	$ 0	$ 0

INCOME TAXES (Details Narrative) - USD ($) $ in Thousands	12 Months Ended
INCOME TAXES (Details Narrative) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets And Liabilities [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 142,947	$ 99,713
Operating Loss Carryforwards	550,619
Research and Development Carryforward	$ 15,217
Us Federal Income Tax [Member]
Deferred Tax Assets And Liabilities [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	34.00%	34.00%

LICENSE AGREEMENTS (Details Narrative) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
License Agreement [Abstract]
License revenue	$ 152	$ 152	$ 152
Deferred Revenue	1,100	1,219	1,371
Income taxes	0	0	0
Other Research and Development Expense	$ 149,793	$ 96,886	$ 66,490

RELATED PARTY TRANSACTIONS (Details Narrative) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Other research and development	$ 149,793	$ 96,886	$ 66,490
Prepaid Research And Development	9,691	8,056
Lfb Group [Member]
Related Party Transaction [Line Items]
Other research and development	200	2,300	8,100
Shared Services Agreement [Member]
Related Party Transaction [Line Items]
Costs and Expenses, Related Party	$ 1,600	$ 1,200	$ 800

COMMITMENTS AND CONTINGENCIES (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Payment due by period, Contractual obligations, Operating leases, Total	$ 35,346
Payment due by period, Contractual obligations, Operating leases, Less than 1 year	1,362
Payment due by period, Contractual obligations, Operating leases, 1-3 years	21,051
Payment due by period, Contractual obligations, Operating leases, 3-5 years	2,742
Payment due by period, Contractual obligations, Operating leases, More than 5 years	10,191
Operating Leases [Member]
Payment due by period, Contractual obligations, Operating leases, Total	16,996
Payment due by period, Contractual obligations, Operating leases, Less than 1 year	1,362
Payment due by period, Contractual obligations, Operating leases, 1-3 years	2,701
Payment due by period, Contractual obligations, Operating leases, 3-5 years	2,742
Payment due by period, Contractual obligations, Operating leases, More than 5 years	10,191
Contract manufacturer [Member]
Payment due by period, Contractual obligations, Operating leases, Total	18,350
Payment due by period, Contractual obligations, Operating leases, Less than 1 year	0
Payment due by period, Contractual obligations, Operating leases, 1-3 years	18,350
Payment due by period, Contractual obligations, Operating leases, 3-5 years	0
Payment due by period, Contractual obligations, Operating leases, More than 5 years	$ 0

COMMITMENTS AND CONTINGENCIES (Details Narrative) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Leases, Rent Expense, Net, Total	$ 1,400	$ 1,400	$ 1,600
Payment due by period, Contractual obligations, Operating leases, Total	35,346
Contractual obligations [Member]
Payment due by period, Contractual obligations, Operating leases, Total	18,400
Operating Leases [Member]
Payment due by period, Contractual obligations, Operating leases, Total	$ 16,996

QUARTERLY FINANCIAL INFORMATION (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Table Text Block Supplement [Abstract]
License revenue	$ 38	$ 38	$ 38	$ 38	$ 38	$ 38	$ 38	$ 38
Total costs and expenses	54,188	34,366	44,383	40,615	31,073	31,623	28,463	27,704	$ 174,552	$ 118,864	$ 79,121
Net loss	$ (53,861)	$ (33,951)	$ (44,142)	$ (41,529)	$ (30,860)	$ (31,536)	$ (28,353)	$ (27,727)
Basic and diluted net loss per common share	$ (0.68)	$ (0.43)	$ (0.59)	$ (0.59)	$ (0.46)	$ (0.48)	$ (0.45)	$ (0.52)	$ (2.30)	$ (1.91)	$ (1.60)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Label	Element	Value
Restricted Cash	us-gaap_RestrictedCash	$ 1,241,000
Restricted Cash	us-gaap_RestrictedCash	587,000
Restricted Cash	us-gaap_RestrictedCash	$ 583,000