Cue Biopharma (CUE) 10-Q 13 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Nov. 08, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	CUE
Entity Registrant Name	Cue Biopharma, Inc.
Entity Central Index Key	1,645,460
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Common Stock, Shares Outstanding		20,133,266

Balance Sheets (Unaudited)

Balance Sheets (Unaudited) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 15,842,000	$ 63,534,000
Marketable securities	23,339,000
Restricted cash, short-term	50,000	50,000
Prepaid expenses and other current assets	1,380,000	1,256,000
Deposits, short term		225,000
Total current assets	40,611,000	65,065,000
Property and equipment, net	2,869,000	1,691,000
Deposits	777,000
Trademark	175,000	175,000
Restricted cash, long term	150,000
Long-term service contract		23,000
Total assets	44,582,000	66,954,000
Current liabilities:
Accounts payable	997,000	1,660,000
Accrued expenses	2,268,000	1,151,000
Research and development contract liability, current portion	1,095,000	2,500,000
Deferred rent	225,000	36,000
Total current liabilities	4,585,000	5,347,000
Research and development contract liability, net of current portion	593,000
Total liabilities	5,178,000	5,347,000
Stockholders’ equity:
Preferred Stock, $0.001 par value; 10,000,000 shares authorized and 0 shares issued and outstanding at September 30, 2018 and December 31, 2017
Common stock, $0.001 par value; 50,000,000 shares authorized; 20,133,266 and 19,459,194 shares issued and outstanding, at September 30, 2018 and December 31, 2017, respectively	20,000	19,000
Common stock to be issued		1,000
Additional paid in capital	99,584,000	94,408,000
Accumulated other comprehensive loss	(20,000)
Accumulated deficit	(60,180,000)	(32,821,000)
Total stockholders’ equity	39,404,000	61,607,000
Total liabilities and stockholders’ equity	$ 44,582,000	$ 66,954,000

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Sep. 30, 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	50,000,000	50,000,000
Common stock, shares issued	20,133,266	19,459,194
Common stock, shares outstanding	20,133,266	19,459,194

Statements of Operations and Ot

Statements of Operations and Other Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Collaboration revenue	$ 449		$ 812
Operating expenses:
General and administrative	2,895	$ 1,030	6,821	$ 2,914
Research and development	10,313	4,002	21,721	9,881
Total operating expenses	13,208	5,032	28,542	12,795
Loss from operations	(12,759)	(5,032)	(27,730)	(12,795)
Other income (expense):
Interest income	102		272
Other income (expense), net	98		99
Total other income (expense)	200		371
Net loss	$ (12,559)	$ (5,032)	$ (27,359)	$ (12,795)
Net loss per share basic and diluted	$ (0.62)	$ (0.47)	$ (1.36)	$ (1.20)
Weighted average common shares outstanding, basic and diluted	20,132,277	10,635,684	20,111,519	10,635,684
Other comprehensive loss:
Unrealized loss from available-for-sale securities, net of tax of $0	$ (20)		$ (20)
Total other comprehensive loss	(20)		(20)
Comprehensive loss	$ (12,579)	$ (5,032)	$ (27,379)	$ (12,795)

Statements of Operations and _2

Statements of Operations and Other Comprehensive Loss (Parenthetical) (Unaudited) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Income Statement [Abstract]
Unrealized gains (losses) from available-for-sale securities. Net of tax	$ 0	$ 0

Statements of Cash Flows (Unaud

Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities
Net loss	$ (27,359,000)	$ (12,795,000)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation	556,000	293,000
Stock-based compensation expense	5,163,000	2,001,000
Deferred rent	188,000	(82,000)
Non-cash investment expense	(52,000)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(101,000)	(300,000)
Deposits	(551,000)	(109,000)
Accounts payable	(662,000)	222,000
Accrued expenses	1,117,000	317,000
Research and development contract liability	(812,000)	157,000
Net cash used in operating activities	(22,513,000)	(10,296,000)
Cash flows from investing activities
Purchases of property and equipment	(1,734,000)	(1,011,000)
Purchases of marketable securities	(23,307,000)
Acquisition of trademark		(175,000)
Net cash used in investing activities	(25,041,000)	(1,186,000)
Cash flows from financing activities
Payments of deferred public offering costs		(44,000)
Proceeds from the exercise of stock options	12,000
Net cash provided by (used in) financing activities	12,000	(44,000)
Net decrease in cash, cash equivalents, and restricted cash	(47,542,000)	(11,526,000)
Cash, cash equivalents, and restricted cash at beginning of period	63,584,000	14,976,000
Cash, cash equivalents, and restricted cash at end of period	$ 16,042,000	3,450,000
Supplemental disclosures of cash flow information:
Accrual of deferred offering costs		$ 197,000

Organization and Basis of Prese

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Basis of Presentation	1. Cue Biopharma, Inc. (the “Company”) was incorporated in the State of Delaware on December 31, 2014 under the name Imagen Biopharma, Inc., and completed its organization, formation and initial capitalization activities effective as of January 1, 2015. In October 2016, the Company changed its name to Cue Biopharma, Inc. The Company’s corporate office and research facilities are located in Cambridge, Massachusetts. The Company is a pre-clinical biopharmaceutical company that is developing a novel and proprietary class of biologic drugs for the selective modulation of the human immune system to treat a broad range of cancers, chronic infectious diseases, and autoimmune disorders. The Company is in the development stage and has incurred recurring losses and negative cash flows from operations. As of September 30, 2018, the Company had cash, cash equivalents and marketable securities of approximately $39,181,000. Management believes that current cash, cash equivalents and marketable securities on hand at September 30, 2018 should be sufficient to fund operations for at least the next twelve months from the date of issuance of these financial statements; however, the future viability of the Company is dependent on its ability to raise additional capital to finance its operations and to fund increased research and development costs in order to seek approval for commercialization of its product candidates. The Company’s failure to raise capital as and when needed would have a negative impact on its financial condition and its ability to pursue its business strategies as this capital is necessary for the Company to perform the research and development activities required to develop the Company’s product candidates in order to generate future revenue streams.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Basis of Presentation The accompanying financial statements as of September 30, 2018, and for the three and nine months ended September 30, 2018 and 2017, have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) for Form 10-Q. Accordingly, they do not include all of the information and footnotes required by United States Generally Accepted Accounting Principles, (“U.S. GAAP”) for complete financial statements. In the opinion of management, these financial statements reflect all adjustments which are necessary for a fair statement of the Company’s financial position and results of its operations, as of and for the periods presented. These financial statements should be read in conjunction with the financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K filed with the SEC on March 29, 2018. The information presented in the financial statements and related notes as of September 30, 2018, and for the three and nine months ended September 30, 2018 and 2017, is unaudited. The December 31, 2017 balance sheet included herein was derived from the audited financial statements as of that date, but does not include all disclosures, including notes, required by U.S. GAAP for complete financial statements. Interim results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2018, or any future periods. Reclassification Certain amounts previously reported in current liabilities for the prior period have been reclassified to the current period presentation to segregate accounts payable and accrued liabilities to conform with current period presentation. Also, certain amounts previously reported in research and development contract advances have been reclassified to the current period presentation to combine research and development contract advances and prepaid expenses. In addition, certain amounts previously reported as reductions to research and development expenses have been reclassified to collaboration revenue to conform with current period presentation. There was no impact to reported net loss. The reclassifications did not have a material impact on previously reported financial statements. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expense during the reporting period. Significant estimates include the accounting for revenue recognition, collaboration agreements, potential liabilities, the assumptions utilized in valuing stock-based compensation issued for services, the realization of deferred tax assets, and the impairment of long-lived assets and intangibles. Actual results could differ from those estimates. Risks and Uncertainties The Company’s operations are subject to a number of factors that may affect its operating results and financial condition. Such factors include, but are not limited to: the Company’s ability to determine candidates for clinical testing, the results of clinical testing and trial activities of the Company’s product candidates, the Company’s ability to obtain regulatory approval to market its product candidates, the Company’s intellectual property, competition from products manufactured and sold or being developed by other companies, the price of, and demand for, the Company’s product candidates if approved for sale, the Company’s ability to negotiate favorable licensing or other manufacturing and marketing agreements for its product candidates, and the Company’s ability to raise capital. The Company currently has no commercially approved product candidates and there can be no assurance that the Company’s research and development programs will be successfully commercialized. Developing and commercializing a product requires significant time and capital and is subject to regulatory review and approval, as well as competition from other biotechnology and pharmaceutical companies. The Company operates in an environment of rapid change and is dependent upon the continued services of its employees and consultants and obtaining and protecting its intellectual property. Cash Concentrations The Company maintains its cash balances with a financial institution in Federally-insured accounts and may periodically have cash balances in excess of insurance limits. The Company maintains its accounts with a financial institution with a high credit rating. The Company has not experienced any losses to date and believes that it is not exposed to any significant credit risk on cash. Cash and Cash Equivalents The Company considers all highly liquid investments with a maturity of three months or less at the date of purchase to be cash equivalents. The Company currently invests available cash in money market funds of a major financial institution and Unites States Treasury obligations. Marketable Securities Marketable securities consist of investments with original maturities greater than ninety days and less than one year from the balance sheet date. The Company classifies all of its investments as available-for-sale securities. Accordingly, these investments are recorded at fair value, which is based on quoted market prices. Realized gains and losses are determined on a specific identification basis and are included in other comprehensive income (loss). Amortization and accretion of discounts and premiums is recorded in other income. Restricted Cash The Company purchased a $50,000 certificate of deposit to collateralize a credit card account with a commercial bank that was classified as short-term restricted cash as of September 30, 2018 and December 31, 2017. In June 2018, the Company also placed $150,000 in a separate account to collateralize a credit card account with a commercial bank that was classified as long-term restricted cash as of September 30, 2018. Property and Equipment Property and equipment is recorded at cost. Major improvements are capitalized, while maintenance and repairs are charged to expense as incurred. Gains and losses from disposition of property and equipment are included in income and expense when realized. Amortization of leasehold improvements is provided using the straight-line method over the shorter of the lease term or the useful life of the underlying assets. Depreciation of property and equipment is provided using the straight-line method over the following estimated useful lives: Laboratory equipment 5 years Computer and office equipment 3 years Furniture and fixtures 3-8 years The Company recognizes depreciation and amortization expense in general and administrative expenses and in research and development expenses in the Company’s statements of operations, depending on how each category of property and equipment is utilized in the Company’s business activities. Revenue Recognition The Company adopted Accounting Standards Codification, Topic 606, Revenue from Contracts with Customers (“ASC 606”), during 2018. The Company will recognize collaboration revenue under certain of the Company’s license or collaboration agreements that are within the scope of ASC 606. The Company’s contracts with customers typically include promises related to licenses to intellectual property and research and development services. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgement to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. Currently, none of the Company’s contracts include options to acquire additional goods and/or services. Research and Development Expenses Research and development expenses consist primarily of compensation costs, fees paid to consultants, outside service providers and organizations (including research institutes at universities), facility costs, and development and clinical trial costs with respect to the Company’s product candidates. Research and development expenses incurred under contracts are expensed ratably over the life of the underlying contracts, unless the achievement of milestones, the completion of contracted work, or other information indicates that a different pattern of performance is more appropriate. Other research and development expenses are charged to operations as incurred. Nonrefundable advance payments are recognized as an expense as the related services are performed. The Company evaluates whether it expects the services to be rendered at each quarter end and year end reporting date. If the Company does not expect the services to be rendered, the advance payment is charged to expense. Nonrefundable advance payments for research and development services are included in prepaid and other current assets on the balance sheet. To the extent that a nonrefundable advance payment is for contracted services to be performed within 12 months from the reporting date, such advance is included in current assets; otherwise, such advance is included in non-current assets. The Company evaluates the status of its research and development agreements and contracts, and the carrying amount of the related assets and liabilities, at each quarter end and year end reporting date, and adjusts the carrying amounts and their classification on the balance sheet as appropriate. Research and Development Funding Arrangements The Company’s proprietary biologics will require substantial time and funding to continue development. There can be no assurances that any of the Company’s biologics will ultimately become commercially viable product candidates. In order to finance its research and development programs, the Company may periodically enter into collaboration agreements with third parties that provide funding for certain aspects of the Company’s ongoing research and development activities. The Company considers various factors in determining the appropriate accounting treatment for such collaboration agreements, including, among others, the risks of and costs associated with the research and development program being funded, the stage of development of the proprietary biologics subject to the research and development program, the likelihood at initiation that the collaboration arrangement will result in an economically successful outcome to the third party, the continuing involvement of the Company in the research and development program and the expenditure of the funds, the transfer of the financial risk associated with the research and development program to the third party, the intended use of the funds and any restrictions thereon, and the probability of any repayment obligations or other forms of consideration if the proprietary biologics subject to the research and development program are not successfully developed and commercialized. Patent Expenses The Company is the exclusive worldwide licensee of, and has patent applications pending for, numerous domestic and foreign patents. Due to the significant uncertainty associated with the successful development of one or more commercially viable product candidates based on the Company’s research efforts and any related patent applications, all patent costs, including patent-related legal fees, filing fees and other costs are charged to expense as incurred. For the three and nine months ended September 30, 2018, patent expenses were $225,000 and $493,000, respectively, and $139,000 and $345,000 for the three and nine months ended September 30, 2017, respectively. Patent expenses are included in general and administrative expenses in the Company’s statements of operations. Licensing Fees and Costs Licensing fees and costs consist primarily of costs relating to the acquisition of the Company’s license agreement with the Albert Einstein College of Medicine (“Einstein”) further described in Note 8, Related Party Transactions, including related royalties, maintenance fees, milestone payments and product development costs. Licensing fees and costs are charged to expense as incurred. Long-Lived Assets The Company reviews long-lived assets, consisting of property and equipment, for impairment at each fiscal year end or when events or changes in circumstances indicate the carrying value of these assets may exceed their current fair values. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to the estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized for the amount by which the carrying amount of the asset exceeds the fair value of the assets. Assets to be disposed of are separately presented in the balance sheet and reported at the lower of the carrying amount or fair value less costs to sell, and are no longer depreciated. The Company has not historically recorded any impairment to its long-lived assets. In the future, if events or market conditions affect the estimated fair value to the extent that a long-lived asset is impaired, the Company will adjust the carrying value of these long-lived assets in the period in which the impairment occurs. Rent Expense and Deferred Rent Liability Operating lease agreements which contain provisions for future rent increases or periods in which rent payments are reduced or abated are recorded in monthly rent on a straight line basis. The difference between rent expense recorded and the amount paid is credited or charged to a deferred rent liability account. The current portion of deferred rent is included in current liabilities, and the remaining amount is shown in the balance sheets as a non-current liability. Stock-Based Compensation The Company periodically issues stock options to officers, directors, employees, Scientific and Clinical Advisory Board members, non-employees and consultants for services rendered. Such issuances vest and expire according to terms established at the issuance date. Stock-based payments to officers, directors and employees, including grants of employee stock options, are recognized in the financial statements based on their grant date fair values. Stock option grants, which are generally time-vested, are measured at the grant date fair value and charged to operations on a straight-line basis over the service period, which generally approximates the vesting term. The Company also grants performance based awards to periodically to officers of the Company. The Company recognizes compensation costs related to performance awards over the requisite service period if and when the Company concludes that it is probable that the performance condition will be achieved. The fair value of stock options is determined utilizing the Black-Scholes option-pricing model, which is affected by several variables, including the risk-free interest rate, the expected dividend yield, the life of the equity award, the exercise price of the stock option as compared to the fair value of the common stock on the grant date, and the estimated volatility of the common stock over the term of the equity award. Stock options granted to members of the Company’s Scientific and Clinical Advisory Board, non-employees and outside consultants are revalued each reporting period to determine the amount to be recorded as an expense in the respective period. As the stock options vest, they are valued on each vesting date and an adjustment is recorded for the difference between the value already recorded and the value on the date of vesting. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant. Until the Company has established a trading market for its common stock, estimated volatility is based on the average historical volatilities of comparable public companies in a similar industry. The expected dividend yield is based on the current yield at the grant date; the Company has never declared or paid dividends and has no plans to do so for the foreseeable future. As permitted by Staff Accounting Bulletin No. 107, due to the Company’s lack of trading history and option activity, management utilizes the simplified method to estimate the expected term of options at the date of grant. The exercise price is determined based on the fair value of the Company’s common stock at the date of grant. The Company accounts for forfeitures as they occur. The Company recognizes the fair value of stock-based compensation in general and administrative expenses and in research and development expenses in the Company’s statements of operations, depending on the type of services provided by the recipient of the equity award. Comprehensive Loss Comprehensive loss includes net loss as well as other changes in stockholders’ deficit that results from transactions and economic events other than those with stockholders. The Company’s only element of other comprehensive loss is all periods presented was unrealized loss on available-for-sale securities. Earnings (Loss) Per Share The Company’s computation of earnings (loss) per share (“EPS”) for the respective periods includes basic and diluted EPS. Basic EPS is measured as the income (loss) attributable to common stockholders divided by the weighted average number of common shares outstanding for the period. Diluted EPS is similar to basic EPS but presents the dilutive effect on a per share basis of potential common shares that would result from the exercise of outstanding stock options and warrants as if they had been exercised at the beginning of the periods presented, or issuance date, if later. Potential common shares that have an anti-dilutive effect (i.e., those that increase income per share or decrease loss per share) are excluded from the calculation of diluted EPS. Basic and diluted loss per common share is the same for all periods presented because all outstanding stock options and warrants are anti-dilutive. At September 30, 2018 and 2017, the Company excluded the outstanding securities summarized below, which entitle the holders thereof to acquire shares of common stock, from its calculation of earnings per share, as their effect would have been anti-dilutive. September 30, 2018 2017 Common stock warrants 1,252,441 370,370 Common stock options 4,427,821 2,366,221 Total 5,680,262 2,736,591 Recent Accounting Pronouncements and Adopted Standards In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross Versus Net) Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients ASC 606 clarifies the principles for recognizing revenue and develops a common revenue standard for U.S. GAAP providing a more robust framework for addressing revenue issues, improves comparability of revenue recognition practices across entities, industries, jurisdictions, and capital markets, provides more useful information to users of financial statements through improved disclosure requirements, and simplifies the preparation of financial statements by reducing the number of requirements to which an entity must refer. This update is effective for annual periods beginning after December 15, 2017, including interim periods within that reporting period. The Company adopted this standard during 2018. There was no revenue recognized during the year ended December 31, 2017 and therefore no cumulative effect adjustment was required. The Company has recorded approximately $449,000 and $812,000 in collaboration revenue for the three and nine months ended September 30, 2018, respectively, pursuant to this guidance. In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases In July 2018, the FASB issued Accounting Standards Update No. 2018-10, Leases In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows: Restricted Cash (“ASU 2016-18”) . The amendments in this update require that amounts generally described as restricted cash and restricted cash equivalents be included within cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-18 was effective January 1, 2018. As a result of adopting ASU 2016-18, the Company includes its restricted cash balance in the cash and cash equivalents reconciliation of operating, investing and financing activities. in thousands September 30, 2018 2017 Cash and cash equivalents $ 15,842 $ 3,400 Restricted cash 50 50 Restricted cash (long-term) 150 — Total cash, cash equivalents, and restricted cash shown in the statement of cash flows $ 16,042 $ 3,450 In May 2017, the FASB issued Accounting Standards Update No. 2017-09, Compensation-Stock Compensation In July 2017, the FASB issued Accounting Standards Update No. 2017-11, Earnings Per Share Distinguishing Liabilities from Equity Derivatives and Hedging (Part I) Accounting for Certain Financial Instruments with Down Round Features; (Part II) Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception In June 2018, the FASB issued Accounting Standards Update No. 2018-07 (“ASU 2018-07”), Stock Compensation This update 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 is evaluating the impact, if any, of ASU 2018-17 on the Company’s consolidated financial statements. Management does not believe that any other recently issued, but not yet effective, authoritative guidance, if currently adopted, would have a material impact on the Company’s financial statement presentation or disclosures.

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value	3. The Company accounts for its financial assets and liabilities using fair value measurements. The authoritative accounting guidance defines fair value, establishes a framework for measuring fair value under generally accepted accounting principles and enhances disclosures about fair value measurements. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The fair value hierarchy is based on three levels of inputs, of which the first two are considered observable and the last unobservable, that may be used to measure fair value as follows: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The following table presents information about the Company’s assets that are measured at fair value on a recurring basis as of September 30, 2018 and indicate the level of the fair value hierarchy utilized to determine such fair value: Fair Value Measurements as of September 30, 2018 (in thousands) Level 1 Level 2 Level 3 Fair Value Cash equivalents $ 15,842 $ — $ — $ 15,842 Marketable securities — 23,339 — 23,339 Total $ 15,842 $ 23,339 $ — $ 39,181 As of September 30, 2018, the Company’s cash equivalents that are invested in money market funds and United States Treasury securities are valued using Level 1 inputs for identical securities. The Company measures the fair value of marketable securities using Level 2 inputs and primarily relies on quoted prices in active markets for similar marketable securities. During the nine months ended September 30, 2018, there were no transfers between Level 2 and Level 3. As of December 31, 2017, the Company did not have assets measured at fair value as the majority of its assets consisted of cash. The carrying values of accounts receivable, prepaid expenses, other current assets, accounts payable and accrued expenses approximate their fair value due to the short-term nature of these balances.

Marketable Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2018
Investments Debt And Equity Securities [Abstract]
Marketable Securities	4. Marketable Securities As of September 30, 2018, the fair value of available-for-sale marketable securities by type of security was as follows: September 30, 2018 (In thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury Securities $ 23,359 $ — $ (20 ) $ 23,339 $ 23,359 $ — $ (20 ) $ 23,339 At September 30, 2018, marketable securities consisted of $23,339,000 of investments that mature within twelve months. At December 31, 2017, the Company did not have marketable securities as the majority of its assets consisted of cash.

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2018
Property Plant And Equipment [Abstract]
Property and Equipment	5 . Property and equipment as of September 30, 2018 and December 31, 2017 consisted of the following: September 30, 2018 December 31, 2017 (in thousands) Computer and office equipment $ 159 $ 83 Laboratory equipment 3,793 2,205 Furniture and fixtures 79 10 Leasehold improvements — 54 4,031 2,352 Less: Accumulated depreciation (1,162 ) (661 ) Total property and equipment, net $ 2,869 $ 1,691 Depreciation expense for the nine months ended September 30, 2018 and 2017 was approximately $556,000 and $293,000, respectively. During the nine months ended September 30, 2018 there were $55,000 in disposals of fully depreciated lease hold improvements related to our prior lease. There were no disposals of property and equipment for the nine months ended September 30, 2017.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	6 . For stock options requiring an assessment of value during the nine months ended September 30, 2018, the fair value of each stock option award was estimated using the Black-Scholes option-pricing model utilizing the following assumptions: September 30, 2018 Risk-free interest rate 2.43 to 2.92% Expected dividend yield 0% Expected volatility 82.0-83.6% Expected life 4.0 to 7.0 years A summary of stock option activity for the nine months ended September 30, 2018 is as follows: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (in Years) Stock options outstanding at December 31, 2017 2,732,221 $ 4.07 5.76 Granted 1,705,600 $ 11.88 Exercised (2,500 ) $ — Cancelled (7,500 ) $ — Stock options outstanding at September 30, 2018 4,427,821 $ 7.08 5.65 Stock options exercisable at September 30, 2018 1,192,953 $ 3.85 4.72 As of September 30, 2018, total unrecognized stock-based compensation was approximately $17,488,000, which is expected to be recognized as an operating expense in the Company’s statement of operations through July 2022. The intrinsic value of exercisable but unexercised in-the-money stock options at September 30, 2018 was approximately $6,208,000, based on a fair value of $9.05 per share on September 28, 2018. Stock-based compensation for the three and nine months ended September 30, 2018 and 2017 was included in the statement of operations as follows: Three months ended September 30, Nine months ended September 30, (in thousands) 2018 2017 2018 2017 General and administrative $ 856 $ 261 $ 1,828 $ 737 Research and development 1,875 490 3,335 1,264 Total $ 2,730 $ 751 $ 5,163 $ 2,001

Warrants

Warrants	9 Months Ended
	Sep. 30, 2018
Warrants And Rights Note Disclosure [Abstract]
Warrants	7 . Warrants The Company has two tranches of common stock warrants outstanding at September 30, 2018 and December 31, 2017. The first tranche is exercisable for 370,370 shares of common stock issued on June 15, 2015 with an exercise price of $2.70 per share. These warrants were issued with a 7 year life and expire on June 15, 2022. The second tranche is exercisable for 882,071 shares of common stock issued on December 27, 2017 with an exercise price of $9.38 per share. These warrants were issued with a 5 year life and expire on December 26, 2022. The intrinsic value of exercisable but unexercised in-the-money common stock warrants at September 30, 2018 was approximately $2,352,000 based on a fair value of $9.05 per share on September 28, 2018. Each tranche of warrants was evaluated under ASC 480, Distinguishing Liabilities from Equity, and ASC 815, Derivatives and Hedging , and the Company determined that equity classification was appropriate.

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 30, 2018
Revenue From Contract With Customer [Abstract]
Revenue Recognition	8 . Revenue Recognition The Company adopted Accounting Standards Codification, Topic 606, Revenue from Contracts with Customers (“ASC 606”), during 2018. The Company will recognize collaboration revenue under certain of the Company’s license or collaboration agreements that are within the scope of ASC 606. The Company’s contracts with customers typically include promises related to licenses to intellectual property and research and development services. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgement to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. Currently, none of the Company’s contracts include options to acquire additional goods and/or services. The terms of the Company’s arrangements with customers typically include the payment of one or more of the following: (i) Non-refundable, up-front payment, (ii) Development, regulatory and commercial milestone payments, (iii) Future options and (iv) Royalties on net sales of licensed products. Accordingly, the transaction price is generally comprised of a fixed fee due at contract inception and variable consideration in the form of milestone payments due upon the achievement of specified events and tiered royalties earned when customers recognize net sales of licensed products. The Company measures the transaction price based on the amount of consideration to which it expects to be entitled in exchange for transferring the promised goods and/or services to the customer. The Company utilizes the “most likely amount” method to estimate the amount of variable consideration, to predict the amount of consideration to which it will be entitled for its one open contract. Amounts of variable consideration are included in the transaction price 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. At the inception of each arrangement that includes development and regulatory milestone payments, the Company evaluates whether the associated event is considered probable of achievement and estimates the amount to be included in the transaction price using the most likely amount method. Milestone payments that are not within the control of the Company or the licensee, such as those dependent upon receipt of regulatory approval, are not considered to be probable of achievement until the triggering event occurs. At the end of each reporting period, the Company reevaluates the probability of achievement of each milestone and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenue and net loss in the period of adjustment. For arrangements that include sales-based royalties, including milestone payments based upon the achievement of a certain level of product sales, the Company recognizes revenue upon the later of: (i) When the related sales occur or (ii) When the performance obligation to which some or all of the payment has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any development, regulatory or commercial milestones or royalty revenue resulting from any of its collaboration arrangements. Consideration that would be received for optional goods and/or services is excluded from the transaction price at contract inception. The Company allocates the transaction price to each performance obligation identified in the contract on a relative standalone selling price basis, when applicable. However, certain components of variable consideration are allocated specifically to one or more particular performance obligations in a contact to the extent both of the following criteria are met: (i) The terms of the payment relate specifically to the efforts to satisfy the performance obligation or transfer the distinct good or service and (ii) Allocating the variable amount of consideration entirely to the performance obligation or the distinct good or service is consistent with the allocation objective of the standard whereby the amount allocated depicts the amount of consideration to which the entity expects to be entitled in exchange for transferring the promised goods or services. The Company develops assumptions that require judgement to determine the standalone selling price for each performance obligation identified in each contract. The key assumptions utilized in determining the standalone selling price for each performance obligation may include forecasted revenues, development timelines, estimated research and development costs, discount rates, likelihood of exercise and probabilities of technical and regulatory success. Revenue is recognized based on the amount of the transaction price that is allocated to each respective performance obligation when or as the performance obligation is satisfied by transferring a promised good and/or service to the customer. For performance obligations that are satisfied over time, the Company recognizes revenue by measuring the progress toward complete satisfaction of the performance obligation using a single method of measuring progress which depicts the performance in transferring control of the associated goods and/or services to the customer. The Company uses input methods to measure the progress toward the complete satisfaction of performance obligations satisfied over time. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Any such adjustments are recorded on a cumulative catch-up basis, which would affect revenue and net loss in the period of adjustment. As it relates to the Merck Sharp & Dohme Corp. (“Merck”) Revenue is recognized over time by allocating a portion of the Company’s direct costs incurred to provide research and development services related to the performance obligation. Furthermore, the Company has not capitalized any contract costs under the guidance in ASC 340-40, Other Assets and Deferred Costs: Contracts with Customers The Company does not believe that any variable consideration should be included in the transaction price at the date of adoption of ASC 606 in 2018. Such assessment considered the application of the constraint to ensure that estimates of variable consideration would be included in the transaction price only to the extent the Company had a high degree of confidence that revenue would not be reversed in a subsequent reporting period. The Company will re-evaluate the transaction price, including the estimated variable consideration included in the transaction price and all constrained amounts, in each reporting period and as other changes in circumstances occur.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
Related Party Transactions	9 . R The former interim Chief Financial Officer of the Company, who is also the Chief Financial Officer of MDB, a related party, was compensated at a rate of $6,000 per month, reflecting an aggregate charge to operations for the three months ended September 30, 2018 and 2017 of $0 and $18,000, respectively and $24,000 and $54,000 for the nine months ended September 30, 2018 and 2017, respectively. In 2015, the Company entered into a license agreement, (the “Einstein License”) with the Albert Einstein College of Medicine (“Einstein”) for certain patent rights relating to the Company’s core technology platform for the engineering of biologics to control T-cell activity, precision, immune-modulatory drug candidates, and two supporting technologies that enable the discovery of costimulatory signaling molecules (ligands) and T-cell targeting peptides. On July 31, 2017, the Company entered into an amended and restated license agreement which modified certain obligations of the parties under the Einstein License. For the three months ended September 30, 2018 and 2017, the Company incurred approximately $12,500 and $10,000, respectively, and for the nine months ended September 30, 2018 and 2017, the Company incurred approximately $38,000 and $35,000, respectively, in fees and expenses to Einstein in relation to this license.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	10 . Einstein License and Service Agreement The Company’s remaining commitments with respect to the Einstein License are based on the attainment of future milestones. The aggregate amount of milestone payments made under the Einstein License may equal up to $1.85 million for each product, process or service that use the patents covered by the Einstein License, including certain technology received from Einstein relating thereto (“Licensed Products”), and up to $1.85 million for each new indication of a Licensed Product. Additionally, the aggregate amount of one-time milestone payments based on cumulative sales of all Licensed Products may equal up to $5.75 million. The Company is also party to a service agreement with Einstein to support the Company’s ongoing research and development activities. Agreements with Catalent On March 7, 2017, the Company entered into an agreement with Catalent Pharma Solutions, LLC (“Catalent”) for Catalent to provide services on a sequential milestone basis with respect to the development and manufacture of the Company’s lead drug candidate, CUE-101. The services under the agreement are designed to support the preparation and filing of an Investigational New Drug Application with the United States Food and Drug Administration to allow for the commencement of a Phase 1 clinical trial of CUE-101 in the United States. The Company incurred total direct costs under this agreement aggregating $4.3 million during the nine months ended September 30, 2018 and currently estimates that it will incur an additional $0.3 million of such costs during the year ended December 31, 2018. Certain of these agreements contain nonrefundable advance payments for which the Company anticipates receiving the contracted services within 12 months from the date of payment. Management periodically reviews and updates the project’s estimated budget and timeline. Collaboration Agreement with Merck On November 14, 2017, the Company entered into an Exclusive Patent License and Research Collaboration Agreement (the “Collaboration Agreement”) with Merck Sharp & Dohme Corp. (“Merck”) for a partnership to research and develop certain of the Company’s proprietary biologics that target certain autoimmune disease indications (the “Initial Indications”). We view this Collaboration Agreement as a component of our development strategy since it will allow us to advance our autoimmune programs in partnership with a world class pharmaceutical company, while also continuing our focus on our more advanced cancer programs. The research program outlined in the Collaboration Agreement entails (1) our research, discovery and development of certain Immuno-STAT™ drug candidates up to the point of demonstration of certain biologically relevant effects (“Proof of Mechanism”) and (2) the further development by Merck of the Immuno-STAT™ drug candidates that have demonstrated Proof of Mechanism (the “Proposed Product Candidates”) up to the point of demonstration of all or substantially all of the properties outlined in such Proposed Product Candidates’ profiles as described in the Collaboration Agreement. For the purposes of this collaboration, the Company granted to Merck under the Collaboration Agreement an exclusive license under certain of is patent rights, including a sublicense of patent rights licensed from Einstein, to the extent applicable to the specific Immuno-STAT™ that are elected to be developed by Merck. From the effective date of the Collaboration Agreement until the earlier of  (i) the first achievement of Proof of Mechanism for a Immuno-STAT™ drug candidate or (ii) 18 months after the Company notifies the joint steering committee that the first Product Candidate has been synthesized under the research program, the Company is required to forebear from researching, developing or licensing to a third party rights related to any Immuno-STAT™ drug candidate for the treatment of autoimmune diseases other than pursuant to the Collaboration Agreement. On July 12, 2018, the Company announced the generation of the first Product Candidate establishing the end-date of the forbearance period as no later than December 14, 2019. In addition, so long as Merck continues product development on a Proposed Product Candidate, the Company is restricted from conducting any development activities within the Initial Indication covered by such Proposed Product Candidate other than pursuant to the Collaboration Agreement. The Company is not required to forbear at any time, however, from developing other Immuno-STAT™ for use in therapeutic areas other than autoimmune diseases, e.g., for use in treating cancer or infectious diseases. In exchange for the licenses and other rights granted to Merck under the Collaboration Agreement, Merck paid to the Company a $2.5 million nonrefundable up-front payment. Additionally, the Company may be eligible to receive funding in developmental milestone payments, as well as tiered royalties, if all research, development, regulatory and commercial milestones agreed upon by both parties are successfully achieved. Excluding the up-front payment described above, the Company is eligible to earn up to $101 million for the achievement of certain research and development milestones, $120 million for the achievement of certain regulatory milestones and $150 million for the achievement of certain commercial milestones, in addition to tiered royalties on sales, if all pre-specified milestones associated with multiple products across the primary disease indication areas are achieved. The Collaboration Agreement requires the Company to use the first $2.7 million of milestone payments we receive under the agreement to fund contract research. The amount of the royalty payments is a percentage of product sales ranging in the single digits based on the amount of such sales. For the three and nine months ended September 30, 2018, the Company recorded approximately $449,000 and $812,000 in collaboration revenue related to this agreement. There was no revenue recognized during the year ended December 31, 2017. The term of the Collaboration Agreement extends until the expiration of all royalty obligations following a product candidate’s receipt of marketing authorization, at which point Merck’s licenses and sublicenses granted under the agreement shall become fully paid-up, perpetual licenses and sublicenses, as applicable. Royalties on each product subject to the Collaboration Agreement shall continue on a country-by-country basis until the expiration of the later of: (1) the last-to-expire patent claiming the compound on which such product is based and (2) a period of ten years after the first commercial sale of such product in such country. Notwithstanding the foregoing, Merck may terminate the Collaboration Agreement at any time upon 30 days’ notice to the Company. The Collaboration Agreement may also be terminated by either party if the other party is in breach of its obligations thereunder and fails to cure such breach within 90 days after notice or by either party if the other party files for bankruptcy or other similar insolvency proceedings. Leased Facilities On July 29, 2015, the Company entered into an operating lease agreement for its previous laboratory space for the period from August 1, 2015 through April 30, 2018. The lease contained escalating payments during the lease period. The Company records monthly rent expense on the straight-line basis. On November 14, 2016 and January 16, 2018 the Company entered into an amendments to the operating lease agreement that each provided the Company with additional laboratory space. These amendments were effective beginning December 1, 2016 and January 16, 2018, respectively, and continued through the expiration of the lease on April 30, 2018. On January 18, 2018, the Company entered into an operating lease agreement for its laboratory and office space in Cambridge, Massachusetts for the period from May 1, 2018 through April 30, 2021. The lease contains escalating payments during the lease period. Upon execution of this lease agreement the Company prepaid three months of rent, two of which will be held in escrow and credited against future rent payments and one month that was applied to the first months rent. The Company also prepaid seven and one half months rent pursuant to an amendment to the lease agreement executed on June 18, 2018. These amounts were recorded to deposits and prepaid expenses, respectively at September 30, 2018. Future minimum lease payments under these leases at September 30, 2018 are as follows: Year (in thousands) 2018 (fourth quarter) $ 904 2019 4,461 2020 4,911 2021 1,432 Total $ 11,708 Total rent expense of approximately $863,000 and $505,000 was included in the statement of operations for the three months ended September 30, 2018 and 2017, respectively, and $2,250,000 and $1,471,000 for the nine months ended September 30, 2018 and 2017, respectively. On June 18, 2018, the Company entered into an amended lease agreement that provided the Company with a reduction in rental fees for its office and laboratory space in exchange for prepayment of a portion of the fees. This amendment was effective beginning on May 15, 2018 and expires on April 14, 2021. On September 20, 2018, the Company entered into an operating lease for additional laboratory space in Cambridge, Massachusetts for the period from October 15, 2018 through April 14, 2021. The lease contains escalating payments during the lease period. Upon execution of this lease agreement the Company prepaid three months of rent which will be held in escrow and credited against future rent payments. The Company also prepaid twelve months rent pursuant to the lease agreement executed on September 20, 2018. These amounts were recorded to deposits and prepaid expenses, respectively at September 30, 2018. Legal Contingencies The Company may be subject to various legal proceedings from time to time as part of its business. As of September 30, 2018, the Company was not a party to any legal proceedings or threatened legal proceedings, the adverse outcome of which, individually or in the aggregate, would have a material adverse effect on its business, financial condition or results of operations.

Subsequent Event

Subsequent Event	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	11. Subsequent Event Collaboration Agreement with LG Chem Life Sciences On November 6, 2018, the Company entered into a Research Collaboration Agreement (the “Collaboration Agreement”) with LG Chem Life Sciences. (“LG Chem”) related to the development of the Company’s Immuno-STAT Biologics focused in the field of oncology. Pursuant to the Collaboration Agreement the Company granted LG Chem an exclusive license to develop, manufacture and commercialize the Company’s lead product, CUE-101, as well as Immuno-STAT Biologics that target T-cells against two additional cancer antigens, in certain Asian countries (collectively, the “LG Chem Territory”). LG Chem has the option to elect one additional Immuno-STAT biologic for an oncology target within two years of the agreement for a worldwide development and commercialization license, and Cue Biopharma will retain an option to co-develop and co-commercialize the additional program worldwide. Cue Biopharma retains rights to develop and commercialize all assets included in the agreement in the United States and in global markets outside of Asia. In exchange for the licenses and other rights granted to LG Chem under the Collaboration Agreement, LG Chem will make a $5.0 million equity investment in common stock of Cue Biopharma, Inc. and a $5.0 million nonrefundable upfront cash payment. Cue Biopharma is also be eligible to receive up to an additional $400 million in research, development, regulatory and sales milestones. In addition, the Collaboration Agreement also provides that LG Chem will pay the Company tiered single-digit royalties on net sales of commercialized product candidates in the LG Chem Territory.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying financial statements as of September 30, 2018, and for the three and nine months ended September 30, 2018 and 2017, have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”) for Form 10-Q. Accordingly, they do not include all of the information and footnotes required by United States Generally Accepted Accounting Principles, (“U.S. GAAP”) for complete financial statements. In the opinion of management, these financial statements reflect all adjustments which are necessary for a fair statement of the Company’s financial position and results of its operations, as of and for the periods presented. These financial statements should be read in conjunction with the financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K filed with the SEC on March 29, 2018. The information presented in the financial statements and related notes as of September 30, 2018, and for the three and nine months ended September 30, 2018 and 2017, is unaudited. The December 31, 2017 balance sheet included herein was derived from the audited financial statements as of that date, but does not include all disclosures, including notes, required by U.S. GAAP for complete financial statements. Interim results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2018, or any future periods.
Reclassification	Reclassification Certain amounts previously reported in current liabilities for the prior period have been reclassified to the current period presentation to segregate accounts payable and accrued liabilities to conform with current period presentation. Also, certain amounts previously reported in research and development contract advances have been reclassified to the current period presentation to combine research and development contract advances and prepaid expenses. In addition, certain amounts previously reported as reductions to research and development expenses have been reclassified to collaboration revenue to conform with current period presentation. There was no impact to reported net loss. The reclassifications did not have a material impact on previously reported financial statements.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenue and expense during the reporting period. Significant estimates include the accounting for revenue recognition, collaboration agreements, potential liabilities, the assumptions utilized in valuing stock-based compensation issued for services, the realization of deferred tax assets, and the impairment of long-lived assets and intangibles. Actual results could differ from those estimates.
Risks and Uncertainties	Risks and Uncertainties The Company’s operations are subject to a number of factors that may affect its operating results and financial condition. Such factors include, but are not limited to: the Company’s ability to determine candidates for clinical testing, the results of clinical testing and trial activities of the Company’s product candidates, the Company’s ability to obtain regulatory approval to market its product candidates, the Company’s intellectual property, competition from products manufactured and sold or being developed by other companies, the price of, and demand for, the Company’s product candidates if approved for sale, the Company’s ability to negotiate favorable licensing or other manufacturing and marketing agreements for its product candidates, and the Company’s ability to raise capital. The Company currently has no commercially approved product candidates and there can be no assurance that the Company’s research and development programs will be successfully commercialized. Developing and commercializing a product requires significant time and capital and is subject to regulatory review and approval, as well as competition from other biotechnology and pharmaceutical companies. The Company operates in an environment of rapid change and is dependent upon the continued services of its employees and consultants and obtaining and protecting its intellectual property.
Cash Concentrations	Cash Concentrations The Company maintains its cash balances with a financial institution in Federally-insured accounts and may periodically have cash balances in excess of insurance limits. The Company maintains its accounts with a financial institution with a high credit rating. The Company has not experienced any losses to date and believes that it is not exposed to any significant credit risk on cash.
Restricted Cash	Cash and Cash Equivalents The Company considers all highly liquid investments with a maturity of three months or less at the date of purchase to be cash equivalents. The Company currently invests available cash in money market funds of a major financial institution and Unites States Treasury obligations. Marketable Securities Marketable securities consist of investments with original maturities greater than ninety days and less than one year from the balance sheet date. The Company classifies all of its investments as available-for-sale securities. Accordingly, these investments are recorded at fair value, which is based on quoted market prices. Realized gains and losses are determined on a specific identification basis and are included in other comprehensive income (loss). Amortization and accretion of discounts and premiums is recorded in other income. Restricted Cash The Company purchased a $50,000 certificate of deposit to collateralize a credit card account with a commercial bank that was classified as short-term restricted cash as of September 30, 2018 and December 31, 2017. In June 2018, the Company also placed $150,000 in a separate account to collateralize a credit card account with a commercial bank that was classified as long-term restricted cash as of September 30, 2018.
Property and Equipment	Property and Equipment Property and equipment is recorded at cost. Major improvements are capitalized, while maintenance and repairs are charged to expense as incurred. Gains and losses from disposition of property and equipment are included in income and expense when realized. Amortization of leasehold improvements is provided using the straight-line method over the shorter of the lease term or the useful life of the underlying assets. Depreciation of property and equipment is provided using the straight-line method over the following estimated useful lives: Laboratory equipment 5 years Computer and office equipment 3 years Furniture and fixtures 3-8 years The Company recognizes depreciation and amortization expense in general and administrative expenses and in research and development expenses in the Company’s statements of operations, depending on how each category of property and equipment is utilized in the Company’s business activities.
Research and Development Expenses	Revenue Recognition The Company adopted Accounting Standards Codification, Topic 606, Revenue from Contracts with Customers (“ASC 606”), during 2018. The Company will recognize collaboration revenue under certain of the Company’s license or collaboration agreements that are within the scope of ASC 606. The Company’s contracts with customers typically include promises related to licenses to intellectual property and research and development services. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgement to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. Currently, none of the Company’s contracts include options to acquire additional goods and/or services. Research and Development Expenses Research and development expenses consist primarily of compensation costs, fees paid to consultants, outside service providers and organizations (including research institutes at universities), facility costs, and development and clinical trial costs with respect to the Company’s product candidates. Research and development expenses incurred under contracts are expensed ratably over the life of the underlying contracts, unless the achievement of milestones, the completion of contracted work, or other information indicates that a different pattern of performance is more appropriate. Other research and development expenses are charged to operations as incurred. Nonrefundable advance payments are recognized as an expense as the related services are performed. The Company evaluates whether it expects the services to be rendered at each quarter end and year end reporting date. If the Company does not expect the services to be rendered, the advance payment is charged to expense. Nonrefundable advance payments for research and development services are included in prepaid and other current assets on the balance sheet. To the extent that a nonrefundable advance payment is for contracted services to be performed within 12 months from the reporting date, such advance is included in current assets; otherwise, such advance is included in non-current assets. The Company evaluates the status of its research and development agreements and contracts, and the carrying amount of the related assets and liabilities, at each quarter end and year end reporting date, and adjusts the carrying amounts and their classification on the balance sheet as appropriate.
Research and Development Funding Arrangements	Research and Development Funding Arrangements The Company’s proprietary biologics will require substantial time and funding to continue development. There can be no assurances that any of the Company’s biologics will ultimately become commercially viable product candidates. In order to finance its research and development programs, the Company may periodically enter into collaboration agreements with third parties that provide funding for certain aspects of the Company’s ongoing research and development activities. The Company considers various factors in determining the appropriate accounting treatment for such collaboration agreements, including, among others, the risks of and costs associated with the research and development program being funded, the stage of development of the proprietary biologics subject to the research and development program, the likelihood at initiation that the collaboration arrangement will result in an economically successful outcome to the third party, the continuing involvement of the Company in the research and development program and the expenditure of the funds, the transfer of the financial risk associated with the research and development program to the third party, the intended use of the funds and any restrictions thereon, and the probability of any repayment obligations or other forms of consideration if the proprietary biologics subject to the research and development program are not successfully developed and commercialized.
Patent Expenses	Patent Expenses The Company is the exclusive worldwide licensee of, and has patent applications pending for, numerous domestic and foreign patents. Due to the significant uncertainty associated with the successful development of one or more commercially viable product candidates based on the Company’s research efforts and any related patent applications, all patent costs, including patent-related legal fees, filing fees and other costs are charged to expense as incurred. For the three and nine months ended September 30, 2018, patent expenses were $225,000 and $493,000, respectively, and $139,000 and $345,000 for the three and nine months ended September 30, 2017, respectively. Patent expenses are included in general and administrative expenses in the Company’s statements of operations.
Licensing Fees and Costs	Licensing Fees and Costs Licensing fees and costs consist primarily of costs relating to the acquisition of the Company’s license agreement with the Albert Einstein College of Medicine (“Einstein”) further described in Note 8, Related Party Transactions, including related royalties, maintenance fees, milestone payments and product development costs. Licensing fees and costs are charged to expense as incurred.
Long-Lived Assets	Long-Lived Assets The Company reviews long-lived assets, consisting of property and equipment, for impairment at each fiscal year end or when events or changes in circumstances indicate the carrying value of these assets may exceed their current fair values. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to the estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized for the amount by which the carrying amount of the asset exceeds the fair value of the assets. Assets to be disposed of are separately presented in the balance sheet and reported at the lower of the carrying amount or fair value less costs to sell, and are no longer depreciated. The Company has not historically recorded any impairment to its long-lived assets. In the future, if events or market conditions affect the estimated fair value to the extent that a long-lived asset is impaired, the Company will adjust the carrying value of these long-lived assets in the period in which the impairment occurs.
Rent Expense and Deferred Rent Liability	Rent Expense and Deferred Rent Liability Operating lease agreements which contain provisions for future rent increases or periods in which rent payments are reduced or abated are recorded in monthly rent on a straight line basis. The difference between rent expense recorded and the amount paid is credited or charged to a deferred rent liability account. The current portion of deferred rent is included in current liabilities, and the remaining amount is shown in the balance sheets as a non-current liability.
Stock-Based Compensation	Stock-Based Compensation The Company periodically issues stock options to officers, directors, employees, Scientific and Clinical Advisory Board members, non-employees and consultants for services rendered. Such issuances vest and expire according to terms established at the issuance date. Stock-based payments to officers, directors and employees, including grants of employee stock options, are recognized in the financial statements based on their grant date fair values. Stock option grants, which are generally time-vested, are measured at the grant date fair value and charged to operations on a straight-line basis over the service period, which generally approximates the vesting term. The Company also grants performance based awards to periodically to officers of the Company. The Company recognizes compensation costs related to performance awards over the requisite service period if and when the Company concludes that it is probable that the performance condition will be achieved. The fair value of stock options is determined utilizing the Black-Scholes option-pricing model, which is affected by several variables, including the risk-free interest rate, the expected dividend yield, the life of the equity award, the exercise price of the stock option as compared to the fair value of the common stock on the grant date, and the estimated volatility of the common stock over the term of the equity award. Stock options granted to members of the Company’s Scientific and Clinical Advisory Board, non-employees and outside consultants are revalued each reporting period to determine the amount to be recorded as an expense in the respective period. As the stock options vest, they are valued on each vesting date and an adjustment is recorded for the difference between the value already recorded and the value on the date of vesting. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant. Until the Company has established a trading market for its common stock, estimated volatility is based on the average historical volatilities of comparable public companies in a similar industry. The expected dividend yield is based on the current yield at the grant date; the Company has never declared or paid dividends and has no plans to do so for the foreseeable future. As permitted by Staff Accounting Bulletin No. 107, due to the Company’s lack of trading history and option activity, management utilizes the simplified method to estimate the expected term of options at the date of grant. The exercise price is determined based on the fair value of the Company’s common stock at the date of grant. The Company accounts for forfeitures as they occur. The Company recognizes the fair value of stock-based compensation in general and administrative expenses and in research and development expenses in the Company’s statements of operations, depending on the type of services provided by the recipient of the equity award.
Earnings (Loss) Per Share	Comprehensive Loss Comprehensive loss includes net loss as well as other changes in stockholders’ deficit that results from transactions and economic events other than those with stockholders. The Company’s only element of other comprehensive loss is all periods presented was unrealized loss on available-for-sale securities. Earnings (Loss) Per Share The Company’s computation of earnings (loss) per share (“EPS”) for the respective periods includes basic and diluted EPS. Basic EPS is measured as the income (loss) attributable to common stockholders divided by the weighted average number of common shares outstanding for the period. Diluted EPS is similar to basic EPS but presents the dilutive effect on a per share basis of potential common shares that would result from the exercise of outstanding stock options and warrants as if they had been exercised at the beginning of the periods presented, or issuance date, if later. Potential common shares that have an anti-dilutive effect (i.e., those that increase income per share or decrease loss per share) are excluded from the calculation of diluted EPS. Basic and diluted loss per common share is the same for all periods presented because all outstanding stock options and warrants are anti-dilutive. At September 30, 2018 and 2017, the Company excluded the outstanding securities summarized below, which entitle the holders thereof to acquire shares of common stock, from its calculation of earnings per share, as their effect would have been anti-dilutive. September 30, 2018 2017 Common stock warrants 1,252,441 370,370 Common stock options 4,427,821 2,366,221 Total 5,680,262 2,736,591
Recent Accounting Pronouncements and Adopted Standards	Recent Accounting Pronouncements and Adopted Standards In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross Versus Net) Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients ASC 606 clarifies the principles for recognizing revenue and develops a common revenue standard for U.S. GAAP providing a more robust framework for addressing revenue issues, improves comparability of revenue recognition practices across entities, industries, jurisdictions, and capital markets, provides more useful information to users of financial statements through improved disclosure requirements, and simplifies the preparation of financial statements by reducing the number of requirements to which an entity must refer. This update is effective for annual periods beginning after December 15, 2017, including interim periods within that reporting period. The Company adopted this standard during 2018. There was no revenue recognized during the year ended December 31, 2017 and therefore no cumulative effect adjustment was required. The Company has recorded approximately $449,000 and $812,000 in collaboration revenue for the three and nine months ended September 30, 2018, respectively, pursuant to this guidance. In February 2016, the FASB issued Accounting Standards Update No. 2016-02, Leases In July 2018, the FASB issued Accounting Standards Update No. 2018-10, Leases In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows: Restricted Cash (“ASU 2016-18”) . The amendments in this update require that amounts generally described as restricted cash and restricted cash equivalents be included within cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-18 was effective January 1, 2018. As a result of adopting ASU 2016-18, the Company includes its restricted cash balance in the cash and cash equivalents reconciliation of operating, investing and financing activities. in thousands September 30, 2018 2017 Cash and cash equivalents $ 15,842 $ 3,400 Restricted cash 50 50 Restricted cash (long-term) 150 — Total cash, cash equivalents, and restricted cash shown in the statement of cash flows $ 16,042 $ 3,450 In May 2017, the FASB issued Accounting Standards Update No. 2017-09, Compensation-Stock Compensation In July 2017, the FASB issued Accounting Standards Update No. 2017-11, Earnings Per Share Distinguishing Liabilities from Equity Derivatives and Hedging (Part I) Accounting for Certain Financial Instruments with Down Round Features; (Part II) Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception In June 2018, the FASB issued Accounting Standards Update No. 2018-07 (“ASU 2018-07”), Stock Compensation This update 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 is evaluating the impact, if any, of ASU 2018-17 on the Company’s consolidated financial statements. Management does not believe that any other recently issued, but not yet effective, authoritative guidance, if currently adopted, would have a material impact on the Company’s financial statement presentation or disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Summary of Estimated Useful Lives of Assets	Depreciation of property and equipment is provided using the straight-line method over the following estimated useful lives: Laboratory equipment 5 years Computer and office equipment 3 years Furniture and fixtures 3-8 years
Schedule of Anti-dilutive Securities Excluded from Computation of Earnings Per Share	At September 30, 2018 and 2017, the Company excluded the outstanding securities summarized below, which entitle the holders thereof to acquire shares of common stock, from its calculation of earnings per share, as their effect would have been anti-dilutive. September 30, 2018 2017 Common stock warrants 1,252,441 370,370 Common stock options 4,427,821 2,366,221 Total 5,680,262 2,736,591
Summary of Reconciliation of Cash, Cash Equivalents, and Restricted Cash within Statement of Financial Position	The following table provides a reconciliation of cash, cash equivalents, and restricted cash within the statement of financial position that sum to the total of the same such amounts shown in the statement of cash flows. in thousands September 30, 2018 2017 Cash and cash equivalents $ 15,842 $ 3,400 Restricted cash 50 50 Restricted cash (long-term) 150 — Total cash, cash equivalents, and restricted cash shown in the statement of cash flows $ 16,042 $ 3,450

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Fair Value Assets Measured on Recurring Basis	The following table presents information about the Company’s assets that are measured at fair value on a recurring basis as of September 30, 2018 and indicate the level of the fair value hierarchy utilized to determine such fair value: Fair Value Measurements as of September 30, 2018 (in thousands) Level 1 Level 2 Level 3 Fair Value Cash equivalents $ 15,842 $ — $ — $ 15,842 Marketable securities — 23,339 — 23,339 Total $ 15,842 $ 23,339 $ — $ 39,181

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2018
Investments Debt And Equity Securities [Abstract]
Schedule of Fair Value of Available-for-Sale Marketable Securities	As of September 30, 2018, the fair value of available-for-sale marketable securities by type of security was as follows: September 30, 2018 (In thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury Securities $ 23,359 $ — $ (20 ) $ 23,339 $ 23,359 $ — $ (20 ) $ 23,339

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2018
Property Plant And Equipment [Abstract]
Summary of Property and Equipment	Property and equipment as of September 30, 2018 and December 31, 2017 consisted of the following: September 30, 2018 December 31, 2017 (in thousands) Computer and office equipment $ 159 $ 83 Laboratory equipment 3,793 2,205 Furniture and fixtures 79 10 Leasehold improvements — 54 4,031 2,352 Less: Accumulated depreciation (1,162 ) (661 ) Total property and equipment, net $ 2,869 $ 1,691

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Estimated Fair Value of Each Stock Option Award	For stock options requiring an assessment of value during the nine months ended September 30, 2018, the fair value of each stock option award was estimated using the Black-Scholes option-pricing model utilizing the following assumptions: September 30, 2018 Risk-free interest rate 2.43 to 2.92% Expected dividend yield 0% Expected volatility 82.0-83.6% Expected life 4.0 to 7.0 years
Summary of Stock Option Activity	A summary of stock option activity for the nine months ended September 30, 2018 is as follows: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Life (in Years) Stock options outstanding at December 31, 2017 2,732,221 $ 4.07 5.76 Granted 1,705,600 $ 11.88 Exercised (2,500 ) $ — Cancelled (7,500 ) $ — Stock options outstanding at September 30, 2018 4,427,821 $ 7.08 5.65 Stock options exercisable at September 30, 2018 1,192,953 $ 3.85 4.72
Schedule of Stock-Based Compensation Included in Statement of Operations	Stock-based compensation for the three and nine months ended September 30, 2018 and 2017 was included in the statement of operations as follows: Three months ended September 30, Nine months ended September 30, (in thousands) 2018 2017 2018 2017 General and administrative $ 856 $ 261 $ 1,828 $ 737 Research and development 1,875 490 3,335 1,264 Total $ 2,730 $ 751 $ 5,163 $ 2,001

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments for Operating Lease	Future minimum lease payments under these leases at September 30, 2018 are as follows: Year (in thousands) 2018 (fourth quarter) $ 904 2019 4,461 2020 4,911 2021 1,432 Total $ 11,708

Organization and Basis of Pre_2

Organization and Basis of Presentation - Additional Information (Details)	9 Months Ended
	Sep. 30, 2018USD ($)
Organization Consolidation And Presentation Of Financial Statements [Abstract]
State of incorporation	Delaware
Date of incorporation	Dec. 31, 2014
Cash, cash equivalents and marketable securities	$ 39,181,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)Product	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of commercial approved product candidates | Product			0
Collaboration revenue	$ 449,000		$ 812,000
ASC 606
Summary Of Significant Accounting Policies [Line Items]
Revenue recognized					$ 0
Cumulative effect adjustment					0
Collaboration Agreement | ASC 606
Summary Of Significant Accounting Policies [Line Items]
Collaboration revenue	449,000		812,000
General and Administrative Expense | License
Summary Of Significant Accounting Policies [Line Items]
Patent expenses	225,000	$ 139,000	493,000	$ 345,000
Certificate of Deposit
Summary Of Significant Accounting Policies [Line Items]
Short-term restricted cash	50,000		50,000		$ 50,000
Long-term restricted cash	$ 150,000		$ 150,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Estimated Useful Lives of Assets (Details)	9 Months Ended
	Sep. 30, 2018
Laboratory Equipment
Property Plant And Equipment [Line Items]
Estimated useful lives	5 years
Computer and Office Equipment
Property Plant And Equipment [Line Items]
Estimated useful lives	3 years
Furniture and Fixtures | Minimum
Property Plant And Equipment [Line Items]
Estimated useful lives	3 years
Furniture and Fixtures | Maximum
Property Plant And Equipment [Line Items]
Estimated useful lives	8 years

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of Anti-dilutive Securities Excluded from Computation of Earnings Per Share (Details) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	5,680,262	2,736,591
Common Stock Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	1,252,441	370,370
Common Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share	4,427,821	2,366,221

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Summary of Reconciliation of Cash, Cash Equivalents, and Restricted Cash within Statement of Financial Position (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Accounting Policies [Abstract]
Cash and cash equivalents	$ 15,842	$ 63,534	$ 3,400
Restricted cash	50	$ 50	50
Restricted cash (long-term)	150
Total cash, cash equivalents, and restricted cash shown in the statement of cash flows	$ 16,042		$ 3,450

Fair Value - Schedule of Fair V

Fair Value - Schedule of Fair Value Assets Measured on Recurring Basis (Details) $ in Thousands	Sep. 30, 2018USD ($)
Fair Value Assets Measured on Recurring Basis [Line Items]
Marketable securities	$ 23,339
Fair Value Measurements, Recurring Basis
Fair Value Assets Measured on Recurring Basis [Line Items]
Cash equivalents	15,842
Marketable securities	23,339
Total	39,181
Fair Value Measurements, Recurring Basis | Level 1
Fair Value Assets Measured on Recurring Basis [Line Items]
Cash equivalents	15,842
Total	15,842
Fair Value Measurements, Recurring Basis | Level 2
Fair Value Assets Measured on Recurring Basis [Line Items]
Marketable securities	23,339
Total	$ 23,339

Marketable Securities - Schedul

Marketable Securities - Schedule of Fair Value of Available-for-Sale Marketable Securities (Details) $ in Thousands	Sep. 30, 2018USD ($)
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 23,359
Gross Unrealized Losses	(20)
Fair Value	23,339
U.S. Treasury Securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	23,359
Gross Unrealized Losses	(20)
Fair Value	$ 23,339

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) - USD ($)	Sep. 30, 2018	Sep. 30, 2017
Investments Debt And Equity Securities [Abstract]
Marketable securities	$ 23,339,000	$ 0

Property and Equipment - Summar

Property and Equipment - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 4,031	$ 2,352
Less: Accumulated depreciation	(1,162)	(661)
Total property and equipment, net	2,869	1,691
Computer and Office Equipment
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	159	83
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	3,793	2,205
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 79	10
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross		$ 54

Property and Equipment - Additi

Property and Equipment - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Property Plant And Equipment [Line Items]
Depreciation expense	$ 556,000	$ 293,000
Disposals of property and equipment		$ 0
Leasehold Improvements
Property Plant And Equipment [Line Items]
Disposals of property and equipment	$ 55,000

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Estimated Fair Value of Each Stock Option Award (Details)	9 Months Ended
	Sep. 30, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, minimum	2.43%
Risk-free interest rate, maximum	2.92%
Expected dividend yield	0.00%
Expected volatility, minimum	82.00%
Expected volatility, maximum	83.60%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life	4 years
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life	7 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Details) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward
Number of Shares, Outstanding Beginning Balance	2,732,221
Number of Shares, Granted	1,705,600
Number of Shares, Exercised	(2,500)
Number of Shares, Cancelled	(7,500)
Number of Shares, Outstanding Ending Balance	4,427,821	2,732,221
Number of Shares, Exercisable	1,192,953
Weighted Average Exercise Price, Outstanding Beginning Balance	$ 4.07
Weighted Average Exercise Price, Granted	11.88
Weighted Average Exercise Price, Outstanding Ending Balance	7.08	$ 4.07
Weighed Average Exercise Price, Exercisable	$ 3.85
Weighted Average Remaining Contractual Life (in Years)	5 years 7 months 24 days	5 years 9 months 3 days
Weighted Average Remaining Contractual Life (in Years), Exercisable	4 years 8 months 19 days

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($)	Sep. 30, 2018	Sep. 28, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Unrecognized stock-based compensation	$ 17,488,000
Intrinsic value of exercisable stock options	$ 6,208,000
Intrinsic value of exercisable fair value per share		$ 9.05

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of Stock-Based Compensation Included in Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation	$ 2,730	$ 751	$ 5,163	$ 2,001
General and Administrative Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation	856	261	1,828	737
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation	$ 1,875	$ 490	$ 3,335	$ 1,264

Warrants - Additional Informati

Warrants - Additional Information (Details)	Sep. 28, 2018$ / shares	Sep. 30, 2018USD ($)Tranche$ / sharesshares	Dec. 31, 2017$ / sharesshares
Class Of Warrant Or Right [Line Items]
Number of tranches | Tranche		2
First tranche
Class Of Warrant Or Right [Line Items]
Common stock warrants outstanding | shares		370,370	370,370
Exercise price of common stock warrants		$ 2.70	$ 2.70
Common stock warrants life		7 years
Common stock warrants expiration date		Jun. 15, 2022
Warrant
Class Of Warrant Or Right [Line Items]
Intrinsic value of common stock warrants | $		$ 2,352,000
Fair value of common stock	$ 9.05
Second tranche
Class Of Warrant Or Right [Line Items]
Common stock warrants outstanding | shares		882,071	882,071
Exercise price of common stock warrants		$ 9.38	$ 9.38
Common stock warrants life		5 years
Common stock warrants expiration date		Dec. 26, 2022

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Details) $ in Millions	Sep. 30, 2018USD ($)
Disaggregation Of Revenue [Line Items]
Transaction price allocated to single performance obligation	$ 2.5
Current Liabilities | Maximum
Disaggregation Of Revenue [Line Items]
Revenue expected to be recognized	12 months
Contract Liabilities | Minimum
Disaggregation Of Revenue [Line Items]
Revenue expected to be recognized	12 months

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2015SupportingTechnology
Einstein License
Related Party Transaction [Line Items]
Number of supporting technologies | SupportingTechnology					2
Einstein License | License
Related Party Transaction [Line Items]
Patent expenses	$ 12,500	$ 10,000	$ 38,000	$ 35,000
Chief Financial Officer | MDB
Related Party Transaction [Line Items]
Monthly compensation payable to officer			6,000
Aggregate compensation payable to officer	$ 0	$ 18,000	$ 24,000	$ 54,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)

Sep. 20, 2018

May 15, 2018

May 01, 2018

Jan. 16, 2018

Nov. 14, 2017

Dec. 01, 2016

Sep. 30, 2018

Sep. 30, 2017

Sep. 30, 2018

Sep. 30, 2017

Dec. 31, 2018

Dec. 31, 2017

Commitments And Contingencies [Line Items]

Collaboration revenue

$ 449,000

$ 812,000

Lease agreement description

Upon execution of this lease agreement the Company prepaid three months of rent, two of which will be held in escrow and credited against future rent payments and one month that was applied to the first months rent. The Company also prepaid seven and one half months rent pursuant to an amendment to the lease agreement executed on June 18, 2018. These amounts were recorded to deposits and prepaid expenses, respectively at September 30, 2018.

Rent expense

863,000

$ 505,000

$ 2,250,000

$ 1,471,000

Additional lease agreement description

Upon execution of this lease agreement the Company prepaid three months of rent which will be held in escrow and credited against future rent payments. The Company also prepaid twelve months rent pursuant to the lease agreement executed on September 20, 2018. These amounts were recorded to deposits and prepaid expenses, respectively at September 30, 2018.

Amended Lease Agreement

Commitments And Contingencies [Line Items]

Lease agreement effective date

May 15, 2018

Jan. 16, 2018

Dec. 1, 2016

Lease expiration date

Apr. 14, 2021

Apr. 30, 2018

Operating Lease Agreement

Commitments And Contingencies [Line Items]

Lease agreement effective date

Oct. 15, 2018

May 1, 2018

Lease expiration date

Apr. 14, 2021

Apr. 30, 2021

Albert Einstein College Of Medicine | Einstein License And Service Agreement

Commitments And Contingencies [Line Items]

Milestone payments for each product, process or service

$ 1,850,000

Milestone payments for each new indication of licensed product

1,850,000

Aggregate amount of additional milestone payments

5,750,000

Einstein | Collaboration Agreement with Merck

Commitments And Contingencies [Line Items]

Collaborative arrangements expiration period

10 years

Catalent | Agreements with Catalent | Services on Development and Manufacture of Lead Drug Candidate

Commitments And Contingencies [Line Items]

Total direct costs under agreement

$ 4,300,000

Anticipated contracted services to be received, period from date of payment

12 months

Catalent | Agreements with Catalent | Scenario, Forecast | Services on Development and Manufacture of Lead Drug Candidate

Commitments And Contingencies [Line Items]

Total direct costs under agreement

$ 300,000

Merck | Collaboration Agreement with Merck

Commitments And Contingencies [Line Items]

Up front non refundable payment

$ 2,500,000

Achievement of certain research and development milestones

120,000,000

Achievement of certain commercial milestones

150,000,000

Milestone payments received

$ 2,700,000

Collaboration revenue

$ 449,000

$ 812,000

$ 0

Collaboration agreement termination terms days ff written notice period

30 days

Collaboration agreement termination terms days of written notice cure breach before termination days

90 days

Merck | Collaboration Agreement with Merck | Maximum

Commitments And Contingencies [Line Items]

Eligible to earn achievement of certain research and development milestones

$ 101,000,000

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Lease Payments on Operating Leases (Details) $ in Thousands	Sep. 30, 2018USD ($)
Commitments And Contingencies Disclosure [Abstract]
2018 (fourth quarter)	$ 904
2,019	4,461
2,020	4,911
2,021	1,432
Total	$ 11,708

Subsequent Event - Additional I

Subsequent Event - Additional Information (Details) - Subsequent Event - LG Chem Life Sciences $ in Millions	Nov. 06, 2018USD ($)
Subsequent Event [Line Items]
Equity investment nonrefundable upfront cash payment	$ 5
Equity investment for research collaboration agreement	5
Maximum
Subsequent Event [Line Items]
Additional amount receivable research development regulatory and sales milestones	$ 400