T2 Biosystems (TTOO) 10-Q 1 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 30, 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	TTOO
Entity Registrant Name	T2 Biosystems, Inc.
Entity Central Index Key	1,492,674
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		44,038,754

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 60,225	$ 41,799
Accounts receivable	1,734	467
Prepaid expenses and other current assets	2,024	708
Inventories	3,337	1,344
Total current assets	67,320	44,318
Property and equipment, net	8,190	10,015
Restricted cash	180	260
Other assets	206	268
Total assets	75,896	54,861
Current liabilities:
Accounts payable	551	648
Accrued expenses and other current liabilities	4,427	6,218
Derivative liability		2,238
Notes payable	3,399	40,696
Deferred revenue	762	1,736
Current portion of lease incentives	262	246
Total current liabilities	9,401	51,782
Notes payable, net of current portion	38,869	1,008
Lease incentives, net of current portion	553	731
Deferred revenue, net of current portion	91
Derivative liability	2,063
Other liabilities	1,157
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value; 10,000,000 shares authorized; no shares issued and outstanding at September 30, 2018 and December 31, 2017
Common stock, $0.001 par value; 200,000,000 shares authorized; 44,038,754 and 35,948,900 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively	44	36
Additional paid-in capital	325,740	267,421
Accumulated deficit	(302,022)	(266,117)
Total stockholders’ equity	23,762	1,340
Total liabilities and stockholders’ equity	$ 75,896	$ 54,861

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 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 (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	44,038,754	35,948,900
Common stock, shares outstanding	44,038,754	35,948,900

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue:
Total revenue	$ 2,466	$ 1,108	$ 8,708	$ 3,005
Costs and expenses:
Research and development	2,725	5,880	11,193	19,577
Selling, general and administrative	5,873	5,559	19,238	17,192
Total costs and expenses	11,640	13,545	40,204	42,491
Loss from operations	(9,174)	(12,437)	(31,496)	(39,486)
Interest expense, net	(1,836)	(1,718)	(4,910)	(5,008)
Other income, net	243	79	402	260
Net loss and comprehensive loss	$ (10,767)	$ (14,076)	$ (36,004)	$ (44,234)
Net loss per share — basic and diluted	$ (0.25)	$ (0.45)	$ (0.91)	$ (1.43)
Weighted-average number of common shares used in computing net loss per share — basic and diluted	43,762,551	31,420,726	39,363,294	30,873,930
Product [Member]
Revenue:
Total revenue	$ 1,218	$ 739	$ 3,486	$ 2,105
Costs and expenses:
Cost of product revenue	3,042	2,106	9,773	5,722
Research [Member]
Revenue:
Total revenue	$ 1,248	$ 369	$ 5,222	$ 900

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities
Net loss	$ (36,004)	$ (44,234)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,862	2,194
Stock-based compensation expense	7,487	3,806
Change in fair value of derivative instrument	(175)
Loss on sale of T2 owned equipment		134
Loss on disposal of property and equipment	18
Impairment of property and equipment	173
Non-cash interest expense	1,658	1,968
Deferred rent	(162)	(95)
Changes in operating assets and liabilities:
Accounts receivable	(1,267)	(115)
Prepaid expenses and other assets	(1,254)	129
Inventories	(1,191)	(451)
Accounts payable	(40)	31
Accrued expenses and other liabilities	(771)	361
Deferred revenue	(784)	(369)
Net cash used in operating activities	(30,450)	(36,641)
Cash flows from investing activities
Purchases and manufacture of property and equipment	(950)	(2,601)
Net cash used in investing activities	(950)	(2,601)
Cash flows from financing activities
Proceeds from issuance of common stock and stock option exercises, net	1,604	717
Proceeds from issuance of common stock in public offering, net of offering costs	49,236	18,795
Proceeds from issuance of common stock in connection with private offering, net of offering costs		37
Principal repayments of note payable	(1,094)	(898)
Net cash provided by financing activities	49,746	18,651
Net increase (decrease) in cash, cash equivalents and restricted cash	18,346	(20,591)
Cash, cash equivalents and restricted cash at beginning of period	42,059	73,748
Cash, cash equivalents and restricted cash at end of period	60,405	53,157
Supplemental disclosures of cash flow information
Cash paid for interest	2,859	2,967
Supplemental disclosures of noncash activities
Transfer of T2 owned instruments and components to inventory	802
Purchases of property and equipment included in accounts payable and accrued expenses	$ 109	$ 90

Nature of Business

Nature of Business	9 Months Ended
	Sep. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business	1. Nature of Business T2 Biosystems, Inc. (the “Company”) was incorporated on April 27, 2006 as a Delaware corporation with operations based in Lexington, Massachusetts. The Company is an in vitro The Company has devoted substantially all of its efforts to research and development, business planning, recruiting management and technical staff, acquiring operating assets, raising capital, and, most recently, the commercialization and improvement of its existing products. Liquidity and Going Concern At September 30, 2018, the Company had cash and cash equivalents of $60.2 million and an accumulated deficit of $302.0 million. The future success of the Company is dependent on its ability to successfully commercialize its products, obtain regulatory clearance for and successfully launch its future product candidates, obtain additional capital and ultimately attain profitable operations. Historically, the Company has funded its operations primarily through its August 2014 initial public offering, its December 2015 public offering, its September 2016 private investment in public equity (“PIPE”) financing, its September 2017 public offering, its June 2018 public offering, private placements of redeemable convertible preferred stock and through debt financing arrangements. The Company is subject to a number of risks similar to other newly commercial life science companies, including, but not limited to commercially launching the Company’s products, development and market acceptance of the Company’s product candidates, development by its competitors of new technological innovations, protection of proprietary technology, and raising additional capital. Having obtained authorization from the FDA to market the T2Dx, T2Candida, and T2Bacteria, the Company has incurred significant commercialization expenses related to product sales, marketing, manufacturing and distribution. The Company may seek to fund its operations through public equity, private equity or debt financings, as well as other sources. However, the Company may be unable to raise additional funds or enter into such other arrangements when needed, on favorable terms, or at all. The Company’s failure to raise capital or enter into such other arrangements if and when needed would have a negative impact on the Company’s business, results of operations, financial condition and the Company’s ability to develop and commercialize T2Dx, T2Candida, T2Bacteria and other product candidates. Pursuant to the requirements of Accounting Standards Codification (“ASC”) 205-40, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern Management believes that its existing cash and cash equivalents at September 30, 2018 will be sufficient to allow the Company to fund its current operating plan through November 30, 2019. At December 31, 2017, management had concluded that substantial doubt existed about the Company’s ability to continue as a going concern for a period of at least twelve months from the date of issuance of those consolidated financial statements. However, management alleviated the substantial doubt during the nine months ended September 30, 2018. On June 4, 2018, the Company raised net proceeds of $49.2 million through its June 2018 public offering. During the nine months ended September 30, 2018, the Company also received a $2.0 million milestone payment from a co-development partner and received 510(k) clearance for the marketing of T2Bacteria. At December 31, 2017, the conditions that raised substantial doubt regarding the Company’s ability to continue as a going concern resulted from certain elements of the Company’s operating plan being outside of the Company’s control, including the approval of T2Bacteria and receipt of certain development and regulatory milestone payments under the Company’s co-development agreements. Under ASC 205-40, the future receipt of potential funding from the Company’s co-development partners and other resources cannot be considered probable if the plans are not entirely within the Company’s control. T he Term Loan Agreement with CRG requires us to achieve certain annual revenue targets, whereby we are required to pay double the amount of any shortfall as an acceleration of principal payments, and maintain a minimum liquidity amount (Note 6). Should we have fallen short of the revenue target we would have sought a waiver of this provision. There can be no assurances that we would have been successful in obtaining a waiver

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The Company’s financial statements have been prepared in conformity with generally accepted accounting principles in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States GAAP as defined in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). The Company’s condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary, T2 Biosystems Securities Corporation. All intercompany balances and transactions have been eliminated. We have evaluated subsequent events from September 30, 2018 through the date of the issuance of these condensed consolidated financial statements and have determined that no material subsequent events have occurred that would have a material effect on the information presented in these consolidated financial statements. Unaudited Interim Financial Information Certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. The accompanying interim condensed consolidated balance sheet as of September 30, 2018, the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2018 and 2017, the condensed consolidated statements of cash flows for the nine months ended September 30, 2018 and 2017 and the related financial data and other information disclosed in these notes are unaudited. The unaudited interim financial statements have been prepared on the same basis as the audited annual financial statements, and, in the opinion of management, reflect all adjustments, consisting of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of September 30, 2018, and the results of its operations and its cash flows for the three and nine months ended September 30, 2018 and 2017. The results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results to be expected for the year ending December 31, 2018, any other interim periods, or any future year or period. Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker is the Chief Executive Officer. The Company views its operations and manages its business in one operating segment, which is the business of developing and, upon regulatory clearance, commercializing its diagnostic products aimed at lowering mortality rates, improving patient outcomes and reducing the cost of healthcare by helping medical professionals make targeted treatment decisions earlier. Net Loss Per Share Basic net loss per share is calculated by dividing net loss by the weighted-average number of shares of common stock outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is calculated by adjusting the weighted-average number of shares outstanding for the dilutive effect of common stock equivalents outstanding for the period, determined using the treasury-stock method. For purposes of the diluted net loss per share calculation, stock options and unvested restricted stock are considered to be common stock equivalents, but have been excluded from the calculation of diluted net loss per share, as their effect would be anti-dilutive for all periods presented. Therefore, basic and diluted net loss per share applicable to common stockholders was the same for all periods presented. Guarantees As permitted under Delaware law, the Company indemnifies its officers and directors for certain events or occurrences while each such officer or director is, or was, serving at the Company’s request in such capacity. The term of the indemnification is the officer’s or director’s lifetime. The maximum potential amount of future payments the Company could be required to make is unlimited; however, the Company has directors’ and officers’ liability insurance coverage that limits its exposure and enables the Company to recover a portion of any future amounts paid. The Company leases office, laboratory and manufacturing space under noncancelable operating leases. The Company has standard indemnification arrangements under the leases that require it to indemnify the landlords against all costs, expenses, fines, suits, claims, demands, liabilities, and actions directly resulting from any breach, violation or nonperformance of any covenant or condition of the Company’s leases. In the ordinary course of business, the Company enters into indemnification agreements with certain suppliers and business partners where the Company has certain indemnification obligations limited to the costs, expenses, fines, suits, claims, demands, liabilities and actions directly resulting from the Company’s gross negligence or willful misconduct, and in certain instances, breaches, violations or nonperformance of covenants or conditions under the agreements. As of September 30, 2018 and December 31, 2017, the Company had not experienced any material losses related to these indemnification obligations, and no material claims with respect thereto were outstanding. The Company does not expect significant claims related to these indemnification obligations and, consequently, concluded that the fair value of these obligations is negligible, and no related reserves were established. Revenue Recognition The Company adopted ASC 606, Revenue from Contracts with Customers The Company generates revenue from the sale of instruments, consumable diagnostic tests, related services, reagent rental agreements and research and development agreements with third parties. Pursuant to ASC 606, revenue is recognized when a customer obtains control of promised goods or services. The amount of revenue recognized reflects the consideration the Company expects to be entitled to receive in exchange for these goods and services. Once a contract is determined to be within the scope of ASC 606 at contract inception, the Company reviews the contract to determine which performance obligations the Company must deliver and which of these performance obligations are distinct. The Company recognizes as revenues the amount of the transaction price that is allocated to the respective performance obligation when the performance obligation is satisfied or as it is satisfied. Generally, the Company's performance obligations are transferred to customers at a point in time, typically upon shipment, or over time, as services are performed. Most of the Company’s contracts with customers contain multiple performance obligations. For these contracts, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to the separate performance obligations on a relative standalone selling price basis. Product revenue is generated by the sale of instruments and consumable diagnostic tests predominantly through the Company’s direct sales force in the United States and distributors in geographic regions outside the United States. The Company does not offer product return or exchange rights (other than those relating to defective goods under warranty) or price protection allowances to its customers, including its distributors. Payment terms granted to distributors are the same as those granted to end-user customers and payments are not dependent upon the distributors’ receipt of payment from their end-user customers. The Company either sells instruments to customers and international distributors, or retains title and places the instrument at the customer site pursuant to a reagent rental agreement. When an instrument is purchased by a customer, the Company recognizes revenue when the related performance obligation is satisfied (i.e. when the control of an instrument has passed to the customer; typically, at shipping point). When the instrument is placed under a reagent rental agreement, the Company’s customers generally agree to fixed term agreements, which can be extended, and incremental charges on each consumable diagnostic test purchased. Revenue from the sale of consumable diagnostic tests (under a reagent rental agreement) is recognized upon shipment. The transaction price from consumables purchases is allocated between the lease of the instrument (under a contingent rent methodology as provided for in ASC 840, Leases Direct sales of instruments include warranty, maintenance and technical support services typically for one year following the installation of the purchased instrument (“Maintenance Services”). Maintenance Services are separate performance obligations as they are service based warranties and are recognized on a straight-line basis over the service delivery period. After the completion of the initial Maintenance Services period, customers have the option to renew or extend the Maintenance Services typically for additional one-year periods in exchange for additional consideration. The extended Maintenance Services are also service based warranties that represent separate purchasing decisions. The Company recognizes revenue allocated to the extended Maintenance Services performance obligation on a straight-line basis over the service delivery period. The Company warrants that consumable diagnostic tests will be free from defects, when handled according to product specifications, for the stated life of the product. To fulfill valid warranty claims, the Company provides replacement product free of charge. Accordingly, the Company accrues warranty expense associated with the estimated defect rates of the consumable diagnostic tests. Revenue earned from activities performed pursuant to research and development agreements is reported as research revenue in the condensed consolidated statements of operations and comprehensive loss, and is recognized over time using an input method as the work is completed. The related costs are expensed as incurred as research and development expense. The timing of receipt of cash from the Company’s research and development agreements generally differs from when revenue is recognized. Milestones are contingent on the occurrence of future events and are considered variable consideration being constrained until the Company believes a significant revenue reversal will not occur. Refer to Note 11 for further details regarding the Company’s research and development arrangements. Disaggregation of Revenue The Company disaggregates revenue from contracts with customers by type of products and services, as it best depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. The following table disaggregates our revenue by major source (in thousands): Three months ended, September 30, 2018 Nine months ended, September 30, 2018 Product Revenue Instruments $ 504 $ 1,213 Consumables 608 1,929 Instrument Rentals 106 344 Total Product Revenue 1,218 3,486 Research Revenue 1,248 5,222 Total Revenue $ 2,466 $ 8,708 Remaining Performance Obligations Remaining performance obligations represent the transaction price of firm orders for which work has not been performed or goods and services have not been delivered. As of September 30, 2018, the aggregate amount of transaction price allocated to remaining performance obligations for contracts with an original duration greater than one year was $3.8 million. We do not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less and (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for services performed. The Company expects to recognize revenue on the remaining performance obligations over the next 2 years. Significant Judgments Our contracts with customers often include promises to transfer multiple products and services to a customer. Determining whether products and services are considered distinct performance obligations that should be accounted for separately versus together may require significant judgment. Once we determine the performance obligations, the Company determines the transaction price, which includes estimating the amount of variable consideration, based on the most likely amount, to be included in the transaction price, if any. We then allocate the transaction price to each performance obligation in the contract based on a relative stand-alone selling price method. The corresponding revenue is recognized as the related performance obligations are satisfied as discussed in the revenue categories above. Judgment is required to determine the standalone selling price for each distinct performance obligation. We determine standalone selling price based on the price at which the performance obligation is sold separately. If the standalone selling price is not observable through past transactions, we estimate the standalone selling price taking into account available information such as market conditions and the expected costs and margin related to the performance obligations. Contract Assets and Liabilities At September 30, 2018, the Company has recorded $0.9 million of contract assets, which represents unbilled amounts related to work performed under a co-development agreement for which the milestone has not yet been achieved but is probable of being achieved. The Company did not record any contract assets at December 31, 2017. The Company’s contract liabilities consist of upfront payments for research and development contracts and Maintenance Services on instrument sales. We classify these contract liabilities in deferred revenue as current or noncurrent based on the timing of when we expect to recognize revenue. At September 30, 2018 and December 31, 2017, the Company had contract liabilities of $0.7 million and $1.7 million, respectively. Revenue recognized in the nine months ended September 30, 2018 relating to contract liabilities at December 31, 2017 was $1.7 million, and related to performance of research and development services and straight-line revenue recognition associated with maintenance agreements. No revenue was recognized during the three months ended September 30, 2018 relating to contract liabilities at December 31, 2017. Cost to Obtain and Fulfill a Contract The Company does not meet the recoverability criteria to capitalize costs to obtain or fulfill instrument purchases. Reagent rental agreements do not meet the recoverability criteria to capitalize costs to obtain the contracts and the costs to fulfill the contracts are under the scope of ASC 840. At the end of each reporting period, the Company assesses whether any circumstances have changed to meet the criteria for capitalization. The Company did not incur any expenses to obtain research and development agreements and costs to fulfill those contracts do not generate or enhance resources of the entity. As such, no costs to obtain or fulfill contracts have been capitalized at period end. Cost of Product Revenue Cost of product revenue includes the cost of materials, direct labor and manufacturing overhead costs used in the manufacture of consumable diagnostic tests sold to customers and related license and royalty fees. Cost of product revenue also includes depreciation on revenue generating T2Dx instruments that have been placed with customers under reagent rental agreements; costs of materials, direct labor and manufacturing overhead costs on the T2Dx instruments sold to customers; and other costs such as customer support costs, royalties and license fees, warranty and repair and maintenance expense on the T2Dx instruments that have been placed with customers under reagent rental agreements. Research and Development Costs Costs incurred in the research and development of the Company’s product candidates are expensed as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including activities associated with performing services under research revenue arrangements, costs associated with the manufacture of developed products and include salaries and benefits, stock compensation, research‑related facility and overhead costs, laboratory supplies, equipment and contract services. Recent Accounting Standards From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption. Accounting Standards Adopted In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows Restricted Cash In June 2014, the FASB issued amended guidance, ASU No. 2014-09, Revenue from Contracts with Customers Revenue Recognition Accounting Standards Issued, Not Adopted In February 2016, the FASB issued ASU No. 2016-02, Leases Emerging Growth Company Status In April 2012, the Jumpstart Our Business Startups Act, or the JOBS Act, was enacted in the United States. Section 107 of the JOBS Act provides that an “emerging growth company” can take advantage of the extended transition period provided in Section 7(a)(2)(B) of the Securities Act, as amended, for complying with new or revised accounting standards. Thus, an emerging growth company can delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. We have irrevocably elected not to avail ourselves of this extended transition period and, as a result, we will adopt new or revised accounting standards on the relevant dates on which adoption of such standards is required for non-emerging growth companies.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements The Company measures the following financial assets at fair value on a recurring basis. There were no transfers between levels of the fair value hierarchy during any of the periods presented. The following tables set forth the Company’s financial assets carried at fair value categorized using the lowest level of input applicable to each financial instrument as of September 30, 2018 and December 31, 2017 (in thousands): Balance at September 30, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Cash $ 1,508 $ 1,508 $ — $ — Money market funds 58,717 58,717 — — Restricted cash 180 180 — — $ 60,405 $ 60,405 $ — $ — Liabilities: Derivative liability $ 2,063 $ — $ — $ 2,063 $ 2,063 $ — $ — $ 2,063 Balance at December 31, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Cash $ 3,463 $ 3,463 $ — $ — Money market funds 38,336 38,336 — — Restricted cash 260 260 — — $ 42,059 $ 42,059 $ — $ — Liabilities: Derivative liability $ 2,238 $ — $ — $ 2,238 $ 2,238 $ — $ — $ 2,238 The Company’s Term Loan Agreement with CRG (Note 6) contains certain provisions that change the underlying cash flows of the instrument, including an interest-only period dependent on the achievement of receiving 510(k) clearance for the marketing of T2Bacteria by the FDA by a certain date (the “Approval Milestone”), which originally was April 30, 2018 During the fourth quarter of 2017, the Company received communication from the FDA that suggested the approval timeline of T2Bacteria could be longer than the Company initially anticipated. The delay resulted in an increase in the probability of not achieving the Approval Milestone by April 30, 2018, as well as an increase in the probability of the payment of contingent interest in future periods, based on the contractual payments that exist as of December 31, 2017. At December 31, 2017, the Company recorded a derivative liability related to the Company’s Term Loan Agreement with CRG of $2.2 million. The estimated fair value of the derivative liability was determined using a probability-weighted discounted cash flow model that includes principal and interest payments under the following scenarios: FDA approval by April 30, 2018 (40%), FDA approval after April 30, 2018 (20%) and no FDA approval (40%). In March 2018, the Term Loan Agreement was amended to extend the Approval Milestone to June 30, 2018, which was achieved in May 2018, to extend the additional $10.0 million funding through September 27, 2018 and reduce the fiscal year 2018 product revenue target to $7.0 million. The fair value of the derivative at September 30, 2018 is $2.1 million. Should the Company’s assessment of these probabilities change, including amendments of certain revenue targets, there could be a change to the fair value of the derivative liability. The following table provides a roll-forward of the fair value of the derivative liability (in thousands): Balance at December 31, 2017 $ 2,238 Change in fair value of derivative liability, recorded as interest expense (175 ) Balance at September 30, 2018 $ 2,063

Restricted Cash

Restricted Cash	9 Months Ended
	Sep. 30, 2018
Restricted Cash [Abstract]
Restricted Cash	4. Restricted Cash The Company is required to maintain a security deposit for its operating lease agreement for the duration of the lease agreement and for its credit cards as long as they are in place. At September 30, 2018 and December 31, 2017, the Company had certificates of deposit for $180,000 and $260,000, respectively, which represented collateral as security deposits for its operating lease agreement for its facility and its credit cards. The $80,000 change is classified as unrestricted cash at September 30, 2018.

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information	9 Months Ended
	Sep. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Supplemental Balance Sheet Information	5. Supplemental Balance Sheet Information Inventories Inventories are stated at the lower of cost or net realizable value on a first-in, first-out basis and are comprised of the following (in thousands): September 30, 2018 December 31, 2017 Raw materials $ 715 $ 539 Work-in-process 2,069 562 Finished goods 553 243 Total inventories, net $ 3,337 $ 1,344 Property and Equipment Property and equipment consists of the following (in thousands): September 30, 2018 December 31, 2017 Office and computer equipment $ 409 $ 409 Software 751 743 Laboratory equipment 4,390 4,224 Furniture 200 200 Manufacturing equipment 695 910 Manufacturing tooling and molds 576 255 T2-owned instruments and components 6,758 7,370 Leasehold improvements 3,437 3,437 Construction in progress 1,701 1,591 18,917 19,139 Less accumulated depreciation and amortization (10,727 ) (9,124 ) Property and equipment, net $ 8,190 $ 10,015 Construction in progress is primarily comprised of equipment and leasehold improvement projects that have not been placed in service. T2-owned instruments and components is comprised of raw materials and work-in-process inventory that are expected to be used or used to produce T2-owned instruments, based on our business model and forecast, and completed instruments that will be used for internal research and development, clinical studies or reagent rental agreements with customers. At September 30, 2018, there were no raw materials and work-in-process inventory in T2-owned instruments and components compared to $0.8 million at December 31, 2017. Completed T2-owned instruments are placed in service once installation procedures are completed and are depreciated over five years. Depreciation expense for T2-owned instruments placed at customer sites pursuant to reagent rental agreements is recorded as a component of cost of product revenue and totaled approximately $0.2 million for the three months ended September 30, 2018 and 2017 and $0.7 million for the nine months ended September 30, 2018 and 2017. Depreciation expense for T2-owned instruments used for internal research and development and clinical studies is recorded as a component of research and development expense. During the fourth quarter of 2017, the Company received communication from the FDA that suggested the approval timeline for T2Bacteria would be longer than the Company initially anticipated. The Company assessed the recoverability of T2-owned instruments based on delayed T2Bacteria cash flows and recorded an impairment charge of related to T2-owned instruments and components. The fair value used in the impairment calculation was based on the best estimated selling price of the underlying T2-owned instruments, less the estimated cost to sell the instruments. During the nine months ended September 30, 2018, the Company recorded a $ million impairment charge, in the cost of product revenue and selling, general and administrative, related to manufacturing equipment for the Candida 1.0 cartridge, which was replaced by the Candida 1.1 cartridge. Accrued Expenses Accrued expenses consist of the following (in thousands): September 30, 2018 December 31, 2017 Accrued payroll and compensation $ 3,077 $ 2,793 Accrued research and development expenses 189 818 Accrued professional services 566 1,018 Other accrued expenses 595 1,589 Total accrued expenses and other current liabilities $ 4,427 $ 6,218 At December 31, 2017, a fee associated with the Company’s Term Loan Agreement (Note 6) of $0.6 million is included in accrued expenses and other current liabilities, to match the classification of the associated debt. At September 30, 2018, the Company’s Term Loan Agreement with CRG and the associated fee are classified as non-current liabilities.

Notes Payable

Notes Payable	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Notes Payable	6. Notes Payable Future principal payments on the notes payable are as follows (in thousands): September 30, 2018 December 31, 2017 Term loan agreement, net of deferred issuance costs of $1.9 million and $2.4 million, respectively $ 40,869 $ 39,228 Equipment lease credit facility, net of deferred issuance cost of $9 thousand and $24 thousand, respectively 1,399 2,476 Total notes payable 42,268 41,704 Less: current portion of notes payable (3,399 ) (40,696 ) Notes payable, net of current portion $ 38,869 $ 1,008 The Term Loan Agreement with CRG is classified as a current liability on the balance sheet at December 31, 2017 based on the Company’s consideration of the probability of violating the minimum liquidity covenant included in the Term Loan Agreement. The Term Loan Agreement with CRG is classified as a non-current liability at September 30, 2018, based on the remote probability of violating the minimum liquidity covenant, as a result of the Company’s June 2018 public offering and FDA market clearance of T2Bacteria. The contractual terms of the agreement require principal payments of $23.2 million and $23.2 million during the years ended December 31, 2021 and 2022, respectively. Term Loan Agreement In December 2016, the Company entered into a Term Loan Agreement (the “Term Loan Agreement”) with CRG. The Company initially borrowed $40.0 million pursuant to the Term Loan Agreement and could borrow up to an additional $10.0 million at any time through and including July 27, 2018, provided that, among other conditions, the Company receives 510(k) clearance for the marketing of T2Bacteria by the FDA by a certain date (the “Approval Milestone”), which originally was April 30, 2018. The Term Loan Agreement has a six-year term with three years (through December 30, 2019) of interest-only payments, which period shall be extended to four years (through December 30, 2020) if the Company achieves the Approval Milestone, after which quarterly principal and interest payments will be due through the December 30, 2022 maturity date. Interest on the amounts borrowed under the Term Loan Agreement accrues at an annual fixed rate of (a) prior to the Approval Milestone, 12.5%, 4.0% of which may be deferred during the interest-only period by adding such amount to the aggregate principal loan amount and (b) following the Approval Milestone, 11.5%, 3.5% of which may be deferred during the interest-only period by adding such amount to the aggregate principal loan amount. In addition, if the Company achieves certain financial performance metrics, the loan will convert to interest-only until the December 30, 2022 maturity, at which time all unpaid principal and accrued unpaid interest will be due and payable. The Company is required to pay CRG a financing fee based on the loan principal amount drawn. The Company is also required to pay a final payment fee of 8.0% of the principal outstanding upon repayment. The Company is accruing the final payment fee as interest expense and it is included as a current liability at December 31, 2017 and a non-current liability at September 30, 2018 on the balance sheet. The Company may prepay all or a portion of the outstanding principal and accrued unpaid interest under the Term Loan Agreement at any time upon prior notice subject to a certain prepayment fee during the first five years of the term and no prepayment fee thereafter. As security for its obligations under the Term Loan Agreement the Company entered into a security agreement with CRG whereby the Company granted a lien on substantially all of its assets, including intellectual property. The Term Loan Agreement also contains customary affirmative and negative covenants for a credit facility of this size and type, including a requirement to maintain a minimum cash balance. The Term Loan Agreement also requires the Company to achieve certain revenue targets, whereby the Company is required to pay double the amount of any shortfall as an acceleration of principal payments. In March 2018, the Term Loan Agreement was amended to extend the Approval Milestone to June 30, 2018, extend the additional $10.0 million funding through September 27, 2018 and reduce the fiscal year 2018 product revenue target to $7.0 million. At September 30, 2018, the Company classified $2.0 million as current notes payable in anticipation of accelerated principal payments. The Term Loan Agreement includes a subjective acceleration clause whereby an event of default, including a material adverse change in the business, operations, or conditions (financial or otherwise), could result in the acceleration of the obligations under the Term Loan Agreement. Under certain circumstances, a default interest rate of an additional 4.0% per annum will apply at the election of CRG on all outstanding obligations during the occurrence and continuance of an event of default. CRG has not exercised its right under this clause, as there have been no such events. During the fourth quarter of 2017, the Company received communication from the FDA that suggested the approval timeline of T2Bacteria would be longer than the Company initially anticipated. The delay resulted in an increase in the probability of not achieving the Approval Milestone by April 30, 2018, as well an increase in the probability of the payment of contingent interest in future periods, based on the contractual payments requirements that exist as of December 31, 2017. The Company assessed the terms and features of the Term Loan Agreement, including the interest-only period dependent on the achievement of the Approval Milestone by June 30, 2018, which was achieved in May 2018, and the acceleration of the obligations under the Term Loan Agreement under an event of default, of the Term Loan Agreement in order to identify any potential embedded features that would require bifurcation. In addition, under certain circumstances, a default interest rate of an additional 4.0% per annum will apply at the election of CRG on all outstanding obligations during the occurrence and continuance of an event of default, The Company concluded that the features of the Term Loan Agreement are not clearly and closely related to the host instrument, and represent a single compound derivative that is required to be re-measured at fair value on a quarterly basis. At December 31, 2017, the Company recorded a derivative liability related to the Company’s Term Loan Agreement with CRG of $2.2 million. derivative at September 30, 2018 is $2.1 million. The Company reclassified the derivative liability to non-current liabilities, at September 30, 2018, to match the classification of the related Term Loan Agreement. In December 2016, pursuant to the Term Loan Agreement, the Company made an initial draw of $39.2 million, net of financing fees. The Company used approximately $28.0 million of the initial proceeds to repay approximately $28.0 million of outstanding debt. Upon the repayment of all amounts owed by the Company related to debt outstanding prior to the Term Loan Agreement, all commitments related to prior debt terminated and al security interests granted by the Company were released. In connection with the Term Loan Agreement entered into in December 2016, the Company issued to CRG four separate warrants to purchase a total of 528,958 shares of the Company’s common stock. The warrants are exercisable any time prior to December 30, 2026 at a price of $8.06 per share, with typical provisions for termination upon a change of control or a sale of all or substantially all of the assets of the Company. The warrants are classified within shareholders’ equity, and the proceeds were allocated between the debt and warrants based on their relative fair value. The fair value of the warrants was determined by the Black Scholes Merton option pricing model. The fair value of the warrants at issuance on December 30, 2016 was $1.8 million. Equipment Lease Credit Facility In October 2015, the Company signed a $10.0 million Credit Facility (the “Credit Facility”) with Essex Capital Corporation (the “Lessor”) to fund capital equipment needs. As one of the conditions of the Term Loan Agreement, the Credit Facility is capped at a maximum of $5.0 million. Under the Credit Facility, Essex will fund capital equipment purchases presented by the Company. The Company will repay the amounts borrowed in 36 equal monthly installments from the date of the amount funded. At the end of the 36 month lease term, the Company has the option to (a) repurchase the leased equipment at the lesser of fair market value or 10% of the original equipment value, (b) extend the applicable lease for a specified period of time, which will not be less than one year, or (c) return the leased equipment to the Lessor. In April 2016 and June 2016, the Company completed the first two draws under the Credit Facility, of $2.1 million and $2.5 million, respectively. The Company will make monthly payments of $67,000 under the first draw and $79,000 under the second draw. The borrowings under the Credit Facility are treated as capital leases. The amortization of the assets conveyed under the Credit Facility is included as a component of depreciation expense.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Stockholders' Equity	7. Stockholders’ Equity Private Investment in Public Equity Financing On September 21, 2016, Canon U.S.A., Inc. (“Canon”) became a related party when the Company sold 6,055,341 shares of its common stock (the “Canon Shares”) to Canon at $6.56 per share, the closing price on this date, for an aggregate cash purchase price of $39.7 million. As of September 21, 2016, the Canon Shares represented 19.9% of the outstanding shares of common stock of the Company. In connection with the sale of the Canon Shares, the Company agreed to grant Canon certain board designation rights, including the right to initially appoint a Class I director to the Company’s board of directors. On March 20, 2017, the Company filed with the Securities and Exchange Commission (the “SEC”) a registration statement on Form S-3 for purposes of registering the resale of the Canon Shares with the SEC. Public Offering On September 15, 2017, the Company sold 5,031,250 shares of its common stock in a public offering at $4.00 per share, for an aggregate gross cash purchase price of $20.1 million, or proceeds of $18.8 million after underwriters discount and expenses. On June 4, 2018, the Company sold 7,015,000 shares of its common stock in a public offering at $7.50 per share, for an aggregate gross cash purchase price of $52.6 million, or proceeds of $49.2 million after underwriters discount and expenses. Common Stock The Company authorized 200,000,000 shares of common stock, $0.001 par value per share, of which 44,038,754 and 35,948,900 were outstanding as of September 30, 2018 and December 31, 2017, respectively.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	8. Stock-Based Compensation Stock Incentive Plans 2006 Stock Incentive Plan The Company’s 2006 Employee, Director and Consultant Stock Option Plan (“2006 Plan”) was established for granting stock incentive awards to directors, officers, employees and consultants of the Company. Upon closing of the Company’s IPO in August 2014, the Company ceased granting stock incentive awards under the 2006 Plan. The 2006 Plan provided for the grant of incentive and non-qualified stock options and restricted stock grants as determined by the Company’s board of directors. Under the 2006 Plan, stock options were generally granted with exercise prices equal to or greater than the fair value of the common stock as determined by the board of directors, expired no later than 10 years from the date of grant, and vest over various periods not exceeding 4 years. 2014 Stock Incentive Plan The Company’s 2014 Incentive Award Plan (“2014 Plan”, and together with the 2006 Plan, the “Stock Incentive Plans”), provides for the issuance of shares of common stock in the form of stock options, awards of restricted stock, awards of restricted stock units, performance awards, dividend equivalent awards, stock payment awards and stock appreciation rights to directors, officers, employees and consultants of the Company. Since the establishment of the 2014 Plan, the Company has primarily granted stock options and restricted stock units. Generally, stock options are granted with exercise prices equal to or greater than the fair value of the common stock on the date of grant, expire no later than 10 years from the date of grant, and vest over various periods not exceeding 4 years. The number of shares reserved for future issuance under the 2014 Plan is the sum of (1) 823,529 shares, (2) any shares that were granted under the 2006 Plan which are forfeited, lapsed unexercised or are settled in cash subsequent to the effective date of the 2014 Plan and (3) an annual increase on the first day of each calendar year beginning January 1, 2015 and ending on January 1, 2024, equal to the lesser of (A) 4% of the shares outstanding (on an as-converted basis) on the final day of the immediately preceding calendar year, and (B) such smaller number of shares determined by the Company’s Board of Directors. As of September 30, 2018, there were 755,341 shares available for future grant under the 2014 Plan. Inducement Award Plan The Company’s Inducement Award Plan (“Inducement Plan”), which was adopted in March 2018, provides for the granting of equity awards to new employees, which includes options, restricted stock awards, restricted stock units, performance awards, dividend equivalent awards, stock payment awards and stock appreciation rights. The aggregate number of shares of common stock which may be issued or transferred pursuant to awards under the Inducement Plan is 625,000 shares. Any awards that forfeit, expire, lapse, or are settled for cash without the delivery of shares to the holder are available for the grant of an award under the Inducement Plan. Any shares repurchased by or surrendered to the Company that are returned shall be available for grant of an award under the Inducement Plan. The payment of dividend equivalents in cash in conjunction with any outstanding Award shall not be counted against the shares available for issuance under the Inducement Plan. As of September 30, 2018, there were 262,750 shares available for future grant under the Inducement Plan. Stock Options During the nine months ended September 30, 2018 and 2017, the Company granted stock options with an aggregate fair value of $5.5 million and $2.5 million, respectively, which are being amortized into compensation expense over the vesting period of the stock options as the services are being provided. The following is a summary of stock option activity under the Plans (in thousands, except share and per share amounts): Number of Shares Weighted-Average Exercise Price Per Share Weighted-Average Remaining Contractual Term (In years) Aggregate Intrinsic Value Outstanding at December 31, 2017 3,785,083 $ 7.31 6.88 $ 1,989 Granted 1,542,250 5.66 Exercised (395,245 ) 3.90 1,294 Forfeited (595,291 ) 6.46 Cancelled (100,202 ) 13.73 Outstanding at September 30, 2018 4,236,595 6.99 7.17 8,570 Exercisable at September 30, 2018 2,308,545 7.74 5.59 5,222 Vested or expected to vest at September 30, 2018 3,775,876 7.14 6.92 7,731 Included in the stock options outstanding as of December 31, 2017 are 106,066 performance based options, which were forfeited during the nine month period ended September 30, 2018 as the performance conditions were not achieved. The weighted-average grant date fair values of stock options granted in the nine month periods ended September 30, 2018 and 2017 were $3.55 per share and $3.04 per share, respectively, and were calculated using the following estimated assumptions: Nine Months Ended September 30, 2018 2017 Weighted-average risk-free interest rate 2.66 % 1.98 % Expected dividend yield — % — % Expected volatility 68 % 63 % Expected terms 6.0 years 6.0 years The total fair values of stock options that vested during the nine months ended September 30, 2018 and 2017 were $2.3 million and $3.5 million, respectively. As of September 30, 2018, there was $6.8 million of total unrecognized compensation cost related to unvested stock options granted under the Stock Incentive Plans. Total unrecognized compensation cost will be adjusted for future changes in the estimated forfeiture rate. The Company expects to recognize that cost over a remaining weighted-average period of 2.90 years as of September 30, 2018. Restricted Stock Units During the nine months ended September 30, 2018, the Company awarded shares of restricted stock units to certain employees and directors at no cost to them, which cannot be sold, assigned, transferred or pledged during the restriction period. The restricted stock and restricted stock units, excluding any restricted stock units with market conditions, vest through the passage of time, assuming continued employment. Restricted stock units are not included in issued and outstanding common stock until the shares are vested and released. The fair value of the award at the time of the grant is expensed on a straight line basis. The granted restricted stock units had an aggregate fair value of $6.2 million, which are being amortized into compensation expense over the vesting period of the options as the services are being provided. Included in the restricted stock units granted during the nine months ended September 30, 2018 are 1,179,090 restricted stock units with market conditions, which vest upon the achievement of stock price targets. The compensation cost for restricted stock units with market conditions is being recorded over the derived service period and was $0.9 million and $3.6 million for the three and nine months ended September 30, 2018, respectively. During the nine months ended September 30, 2018, 294,775 restricted stock units with market conditions vested upon achievement of a stock price target causing acceleration of the remaining expense for these units. These restricted stock units vested during the three months ended June 30, 2018 but were not reflected as outstanding shares until the three months ended September 30, 2018 due to a deferred release date. The following is a summary of restricted stock unit activity under the 2014 Plan (in thousands, except share and per share amounts): Number of Shares Weighted-Average Grant Date Fair Value Nonvested at December 31, 2017 606,497 5.23 Granted 1,217,190 5.06 Vested (546,547 ) 5.33 Forfeited (75,017 ) 5.63 Cancelled — — Nonvested at September 30, 2018 1,202,123 4.99 During the nine months ended September 30, 2018, 546,547 restricted stock units vested and 14,803 shares were withheld to cover employee tax. As of September 30, 2018, there was $3.2 million of total unrecognized compensation cost related to unvested restricted stock units granted under the Stock Incentive Plans, including the unrecognized compensation expense of stock options with market conditions deemed probable of vesting. The Company expects to recognize that cost over a remaining weighted-average period of 0.66 years, as of September 30, 2018. Stock-Based Compensation Expense The following table summarizes the stock-based compensation expense resulting from awards granted under stock incentive plans, including the 2014 ESPP, that was recorded in the Company’s results of operations for the periods presented (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Cost of product revenue $ 23 $ 18 $ 408 $ 87 Research and development 409 340 1,271 1,047 Selling, general and administrative 1,601 862 5,561 2,555 Total stock-based compensation expense $ 2,033 $ 1,220 $ 7,240 $ 3,689 For the three months ended September 30, 2018 and 2017, $0.2 million and $0.0 million of stock-based compensation expenses were capitalized as part of inventory or T2Dx instruments and components, respectively. For the nine months ended September 30, 2018 and 2017, $0.3 million and $0.1 million of stock-based compensation expenses were capitalized as part of inventory or T2 instruments and components, respectively.

Warrants

Warrants	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Warrants	9. Warrants In connection with the Term Loan Agreement entered into in December 2016, the Company issued to CRG four separate warrants to purchase a total of 528,958 shares of the Company’s common stock. The warrants are exercisable any time prior to December 30, 2026 at a price of $8.06 per share, with typical provisions for termination upon a change of control or a sale of all or substantially all of the assets of the Company. The warrants are classified within shareholders’ equity, and the proceeds were allocated between the debt and warrants based on their relative fair value. The fair value of the warrants was determined by the Black-Scholes-Merton option pricing model. The fair value of the warrants at issuance was $1.8 million.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Net Loss Per Share	10. Net Loss Per Share The following shares were excluded from the calculation of diluted net loss per share applicable to common stockholders, prior to the application of the treasury stock method, because their effect would have been anti-dilutive for the periods presented: Three and Nine Months Ended September 30, 2018 2017 Options to purchase common shares 4,236,595 3,833,300 Restricted stock units 1,202,123 750,320 Warrants to purchase common stock 528,958 528,958 Total 5,967,676 5,112,578

Co-Development Agreements

Co-Development Agreements	9 Months Ended
	Sep. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Co-Development Agreements	11. Co-Development Agreements Canon US Life Sciences On February 3, 2015, the Company entered into a Co-Development Partnership Agreement (the “Co-Development Agreement”) with Canon U.S. Life Sciences, Inc. (“Canon US Life Sciences”) to develop a diagnostic test panel to rapidly detect Lyme disease. Under the terms of the Co-Development Agreement, the Company received an upfront payment of $2.0 million from Canon US Life Sciences, and the agreement includes an additional $6.5 million of consideration upon achieving certain development and regulatory milestones for total aggregate payments of up to $8.5 million. In October 2015 and June 2018, the Company achieved specified technical requirements and received $1.5 million and $2.0 million, respectively, related to the achievement of the milestones. The Company is eligible to receive an additional $3.0 million under the arrangement related to the achievement of a regulatory milestone. All payments under the Co-Development Agreement are non-refundable once received. The Company will retain exclusive worldwide commercialization rights of any products developed under the Co-Development Agreement, including sales, marketing and distribution and Canon US Life Sciences will not receive any commercial rights and will be entitled to only receive royalty payments on the sales of all products developed under the Co-Development Agreement. Either party may terminate the Co-Development Agreement upon the occurrence of a material breach by the other party (subject to a cure period). On September 21, 2016, Canon became a related party when the Company sold the Canon Shares for an aggregate cash purchase price of $39.7 million, which represented 19.9% of the outstanding shares of common stock of the Company. The Company evaluated the promised goods and services under the Co-Development Agreement and determined that the Co-Development Agreement included one performance obligation, the research and development services. The Company is recognizing revenue for research and development services as a component of research revenue in the condensed consolidated financial statements over time, as the services are delivered. The Company uses the input method by allocating and recognizing revenue over time based on the total full-time equivalent effort incurred to date as a percentage of total full-time equivalent time expected, limited to payments earned. Costs incurred to deliver the services under the Co-Development Agreement are recorded as research and development expense in the condensed consolidated financial statements. Under the Co-Development Agreement, the Company recorded revenue of $0.2 million for the three months ended September 30, 2018 and did not record any revenue for the three months ended September 30, 2017. The Company recorded revenue of $1.5 million and $0.3 million during the nine months ended September 30, 2018 and 2017. Under the Co-Development Agreement, the Company expects to record revenue over the next two years, provided milestones are achieved. Allergan Sales, LLC On November 1, 2016, the Company entered into a Co-Development, Collaboration and Co-Marketing Agreement (the “Allergan Agreement”) with Allergan Sales, LLC (“Allergan Sales”) to develop (1) a direct detection diagnostic test panel that adds one additional bacteria species to the existing T2Bacteria product candidate (the “T2Bacteria II Panel”), and (2) a direct detection diagnostic test panel for testing drug resistance directly in whole blood (the “T2GNR Panel” and, together with the T2Bacteria II Panel, the “Developed Products”). In addition, both the Company and Allergan Sales will participate in a joint research and development committee and Allergan Sales will receive the right to cooperatively market the T2Candida, T2Bacteria, and the Developed Products under the Allergan Agreement to certain agreed-upon customers. On June 1, 2017, the Company and Allergan Sales entered into an Amendment to the Allergan Agreement which primarily modified the project plan to combine the T2Bacteria II Panel and T2GNR Panel into one test panel. Under the terms of the Allergan Agreement, the Company received an upfront payment of $2.0 million from Allergan Sales and will receive additional milestone payments upon achieving certain developmental milestones for total aggregate payments of up to $4.0 million. All payments under the Allergan Agreement are non-refundable once received. The Company will retain exclusive worldwide commercialization rights of any products developed under the Allergan Agreement, including distribution, subject to Allergan Sales’ right to co-market the Developed Products. Allergan Sales, at its election, may co-market T2Candida, T2Bacteria and the Developed Products worldwide to certain agreed-upon customers and will receive a royalty based on its sales for a period of time. The Company evaluated the promised goods and services under the Allergan Agreement and determined that the Allergan Agreement included two performance obligations, the research and development services for the T2Bacteria II Panel and the research and development services for the T2GNR Panel. The Company uses the input method by allocating and recognizing revenue over time based on the total full-time equivalent effort incurred to date as a percentage of total full-time equivalent time expected, limited to payments earned. Costs incurred to deliver the services under the Allergan Agreement are recorded as research and development expense in the consolidated financial statements. The Company recorded revenue of $0.7 million and $0.4 million for the three months ended September 30, 2018 and 2017, respectively, and $2.9 million and $0.6 million for the nine months ended September 30, 2018 and 2017, respectively, under the Allergan Agreement. The Company expects to record revenue over the next three months, provided development and regulatory milestones are achieved. CARB-X In March 2018, the Company was awarded a grant of up to $2.0 million from CARB-X. The collaboration with CARB-X will be used to accelerate the development of new tests to identify bacterial pathogens and resistance markers directly in whole blood more rapidly than is possible using today’s diagnostic tools. The new tests aim to expand the T2Dx instrument product line by detecting 20 additional bacterial species and resistance targets, with a focus on blood borne pathogens on the United States Centers for Disease Control and Prevention (“CDC”) antibiotic resistance threat list. Under this cost-sharing agreement, the Company may be reimbursed up to $1.1 million, with the possibility of up to an additional $0.9 million based on the achievement of certain project milestones. The Company recorded revenue of $0.4 million and $0.9 million for the three and nine months ended September 30, 2018, respectively, under the CARB-X Agreement. The Company expects to record revenue over the next two years, based upon cost-sharing and the achievement of certain project milestones.

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 Company’s financial statements have been prepared in conformity with generally accepted accounting principles in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States GAAP as defined in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). The Company’s condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary, T2 Biosystems Securities Corporation. All intercompany balances and transactions have been eliminated. We have evaluated subsequent events from September 30, 2018 through the date of the issuance of these condensed consolidated financial statements and have determined that no material subsequent events have occurred that would have a material effect on the information presented in these consolidated financial statements.
Unaudited Interim Financial Information	Unaudited Interim Financial Information Certain information and footnote disclosures normally included in the Company’s annual financial statements have been condensed or omitted. Accordingly, these interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017. The accompanying interim condensed consolidated balance sheet as of September 30, 2018, the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2018 and 2017, the condensed consolidated statements of cash flows for the nine months ended September 30, 2018 and 2017 and the related financial data and other information disclosed in these notes are unaudited. The unaudited interim financial statements have been prepared on the same basis as the audited annual financial statements, and, in the opinion of management, reflect all adjustments, consisting of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of September 30, 2018, and the results of its operations and its cash flows for the three and nine months ended September 30, 2018 and 2017. The results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results to be expected for the year ending December 31, 2018, any other interim periods, or any future year or period.
Segment Information	Segment Information Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker is the Chief Executive Officer. The Company views its operations and manages its business in one operating segment, which is the business of developing and, upon regulatory clearance, commercializing its diagnostic products aimed at lowering mortality rates, improving patient outcomes and reducing the cost of healthcare by helping medical professionals make targeted treatment decisions earlier.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing net loss by the weighted-average number of shares of common stock outstanding during the period, without consideration for common stock equivalents. Diluted net loss per share is calculated by adjusting the weighted-average number of shares outstanding for the dilutive effect of common stock equivalents outstanding for the period, determined using the treasury-stock method. For purposes of the diluted net loss per share calculation, stock options and unvested restricted stock are considered to be common stock equivalents, but have been excluded from the calculation of diluted net loss per share, as their effect would be anti-dilutive for all periods presented. Therefore, basic and diluted net loss per share applicable to common stockholders was the same for all periods presented.
Guarantees	Guarantees As permitted under Delaware law, the Company indemnifies its officers and directors for certain events or occurrences while each such officer or director is, or was, serving at the Company’s request in such capacity. The term of the indemnification is the officer’s or director’s lifetime. The maximum potential amount of future payments the Company could be required to make is unlimited; however, the Company has directors’ and officers’ liability insurance coverage that limits its exposure and enables the Company to recover a portion of any future amounts paid. The Company leases office, laboratory and manufacturing space under noncancelable operating leases. The Company has standard indemnification arrangements under the leases that require it to indemnify the landlords against all costs, expenses, fines, suits, claims, demands, liabilities, and actions directly resulting from any breach, violation or nonperformance of any covenant or condition of the Company’s leases. In the ordinary course of business, the Company enters into indemnification agreements with certain suppliers and business partners where the Company has certain indemnification obligations limited to the costs, expenses, fines, suits, claims, demands, liabilities and actions directly resulting from the Company’s gross negligence or willful misconduct, and in certain instances, breaches, violations or nonperformance of covenants or conditions under the agreements. As of September 30, 2018 and December 31, 2017, the Company had not experienced any material losses related to these indemnification obligations, and no material claims with respect thereto were outstanding. The Company does not expect significant claims related to these indemnification obligations and, consequently, concluded that the fair value of these obligations is negligible, and no related reserves were established.
Revenue Recognition	Revenue Recognition The Company adopted ASC 606, Revenue from Contracts with Customers The Company generates revenue from the sale of instruments, consumable diagnostic tests, related services, reagent rental agreements and research and development agreements with third parties. Pursuant to ASC 606, revenue is recognized when a customer obtains control of promised goods or services. The amount of revenue recognized reflects the consideration the Company expects to be entitled to receive in exchange for these goods and services. Once a contract is determined to be within the scope of ASC 606 at contract inception, the Company reviews the contract to determine which performance obligations the Company must deliver and which of these performance obligations are distinct. The Company recognizes as revenues the amount of the transaction price that is allocated to the respective performance obligation when the performance obligation is satisfied or as it is satisfied. Generally, the Company's performance obligations are transferred to customers at a point in time, typically upon shipment, or over time, as services are performed. Most of the Company’s contracts with customers contain multiple performance obligations. For these contracts, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to the separate performance obligations on a relative standalone selling price basis. Product revenue is generated by the sale of instruments and consumable diagnostic tests predominantly through the Company’s direct sales force in the United States and distributors in geographic regions outside the United States. The Company does not offer product return or exchange rights (other than those relating to defective goods under warranty) or price protection allowances to its customers, including its distributors. Payment terms granted to distributors are the same as those granted to end-user customers and payments are not dependent upon the distributors’ receipt of payment from their end-user customers. The Company either sells instruments to customers and international distributors, or retains title and places the instrument at the customer site pursuant to a reagent rental agreement. When an instrument is purchased by a customer, the Company recognizes revenue when the related performance obligation is satisfied (i.e. when the control of an instrument has passed to the customer; typically, at shipping point). When the instrument is placed under a reagent rental agreement, the Company’s customers generally agree to fixed term agreements, which can be extended, and incremental charges on each consumable diagnostic test purchased. Revenue from the sale of consumable diagnostic tests (under a reagent rental agreement) is recognized upon shipment. The transaction price from consumables purchases is allocated between the lease of the instrument (under a contingent rent methodology as provided for in ASC 840, Leases Direct sales of instruments include warranty, maintenance and technical support services typically for one year following the installation of the purchased instrument (“Maintenance Services”). Maintenance Services are separate performance obligations as they are service based warranties and are recognized on a straight-line basis over the service delivery period. After the completion of the initial Maintenance Services period, customers have the option to renew or extend the Maintenance Services typically for additional one-year periods in exchange for additional consideration. The extended Maintenance Services are also service based warranties that represent separate purchasing decisions. The Company recognizes revenue allocated to the extended Maintenance Services performance obligation on a straight-line basis over the service delivery period. The Company warrants that consumable diagnostic tests will be free from defects, when handled according to product specifications, for the stated life of the product. To fulfill valid warranty claims, the Company provides replacement product free of charge. Accordingly, the Company accrues warranty expense associated with the estimated defect rates of the consumable diagnostic tests. Revenue earned from activities performed pursuant to research and development agreements is reported as research revenue in the condensed consolidated statements of operations and comprehensive loss, and is recognized over time using an input method as the work is completed. The related costs are expensed as incurred as research and development expense. The timing of receipt of cash from the Company’s research and development agreements generally differs from when revenue is recognized. Milestones are contingent on the occurrence of future events and are considered variable consideration being constrained until the Company believes a significant revenue reversal will not occur. Refer to Note 11 for further details regarding the Company’s research and development arrangements. Disaggregation of Revenue The Company disaggregates revenue from contracts with customers by type of products and services, as it best depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. The following table disaggregates our revenue by major source (in thousands): Three months ended, September 30, 2018 Nine months ended, September 30, 2018 Product Revenue Instruments $ 504 $ 1,213 Consumables 608 1,929 Instrument Rentals 106 344 Total Product Revenue 1,218 3,486 Research Revenue 1,248 5,222 Total Revenue $ 2,466 $ 8,708 Remaining Performance Obligations Remaining performance obligations represent the transaction price of firm orders for which work has not been performed or goods and services have not been delivered. As of September 30, 2018, the aggregate amount of transaction price allocated to remaining performance obligations for contracts with an original duration greater than one year was $3.8 million. We do not disclose the value of unsatisfied performance obligations for (i) contracts with an original expected length of one year or less and (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for services performed. The Company expects to recognize revenue on the remaining performance obligations over the next 2 years. Significant Judgments Our contracts with customers often include promises to transfer multiple products and services to a customer. Determining whether products and services are considered distinct performance obligations that should be accounted for separately versus together may require significant judgment. Once we determine the performance obligations, the Company determines the transaction price, which includes estimating the amount of variable consideration, based on the most likely amount, to be included in the transaction price, if any. We then allocate the transaction price to each performance obligation in the contract based on a relative stand-alone selling price method. The corresponding revenue is recognized as the related performance obligations are satisfied as discussed in the revenue categories above. Judgment is required to determine the standalone selling price for each distinct performance obligation. We determine standalone selling price based on the price at which the performance obligation is sold separately. If the standalone selling price is not observable through past transactions, we estimate the standalone selling price taking into account available information such as market conditions and the expected costs and margin related to the performance obligations. Contract Assets and Liabilities At September 30, 2018, the Company has recorded $0.9 million of contract assets, which represents unbilled amounts related to work performed under a co-development agreement for which the milestone has not yet been achieved but is probable of being achieved. The Company did not record any contract assets at December 31, 2017. The Company’s contract liabilities consist of upfront payments for research and development contracts and Maintenance Services on instrument sales. We classify these contract liabilities in deferred revenue as current or noncurrent based on the timing of when we expect to recognize revenue. At September 30, 2018 and December 31, 2017, the Company had contract liabilities of $0.7 million and $1.7 million, respectively. Revenue recognized in the nine months ended September 30, 2018 relating to contract liabilities at December 31, 2017 was $1.7 million, and related to performance of research and development services and straight-line revenue recognition associated with maintenance agreements. No revenue was recognized during the three months ended September 30, 2018 relating to contract liabilities at December 31, 2017. Cost to Obtain and Fulfill a Contract The Company does not meet the recoverability criteria to capitalize costs to obtain or fulfill instrument purchases. Reagent rental agreements do not meet the recoverability criteria to capitalize costs to obtain the contracts and the costs to fulfill the contracts are under the scope of ASC 840. At the end of each reporting period, the Company assesses whether any circumstances have changed to meet the criteria for capitalization. The Company did not incur any expenses to obtain research and development agreements and costs to fulfill those contracts do not generate or enhance resources of the entity. As such, no costs to obtain or fulfill contracts have been capitalized at period end.
Cost of Product Revenue	Cost of Product Revenue Cost of product revenue includes the cost of materials, direct labor and manufacturing overhead costs used in the manufacture of consumable diagnostic tests sold to customers and related license and royalty fees. Cost of product revenue also includes depreciation on revenue generating T2Dx instruments that have been placed with customers under reagent rental agreements; costs of materials, direct labor and manufacturing overhead costs on the T2Dx instruments sold to customers; and other costs such as customer support costs, royalties and license fees, warranty and repair and maintenance expense on the T2Dx instruments that have been placed with customers under reagent rental agreements.
Research and Development Costs	Research and Development Costs Costs incurred in the research and development of the Company’s product candidates are expensed as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including activities associated with performing services under research revenue arrangements, costs associated with the manufacture of developed products and include salaries and benefits, stock compensation, research‑related facility and overhead costs, laboratory supplies, equipment and contract services.
Recent Accounting Standards	Recent Accounting Standards From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption. Accounting Standards Adopted In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows Restricted Cash In June 2014, the FASB issued amended guidance, ASU No. 2014-09, Revenue from Contracts with Customers Revenue Recognition Accounting Standards Issued, Not Adopted In February 2016, the FASB issued ASU No. 2016-02, Leases
Emerging Growth Company Status	Emerging Growth Company Status In April 2012, the Jumpstart Our Business Startups Act, or the JOBS Act, was enacted in the United States. Section 107 of the JOBS Act provides that an “emerging growth company” can take advantage of the extended transition period provided in Section 7(a)(2)(B) of the Securities Act, as amended, for complying with new or revised accounting standards. Thus, an emerging growth company can delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. We have irrevocably elected not to avail ourselves of this extended transition period and, as a result, we will adopt new or revised accounting standards on the relevant dates on which adoption of such standards is required for non-emerging growth companies.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Disaggregation of Revenue by Major Source	The following table disaggregates our revenue by major source (in thousands): Three months ended, September 30, 2018 Nine months ended, September 30, 2018 Product Revenue Instruments $ 504 $ 1,213 Consumables 608 1,929 Instrument Rentals 106 344 Total Product Revenue 1,218 3,486 Research Revenue 1,248 5,222 Total Revenue $ 2,466 $ 8,708

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities at Fair value on a Recurring Basis	The Company measures the following financial assets at fair value on a recurring basis. There were no transfers between levels of the fair value hierarchy during any of the periods presented. The following tables set forth the Company’s financial assets carried at fair value categorized using the lowest level of input applicable to each financial instrument as of September 30, 2018 and December 31, 2017 (in thousands): Balance at September 30, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Cash $ 1,508 $ 1,508 $ — $ — Money market funds 58,717 58,717 — — Restricted cash 180 180 — — $ 60,405 $ 60,405 $ — $ — Liabilities: Derivative liability $ 2,063 $ — $ — $ 2,063 $ 2,063 $ — $ — $ 2,063 Balance at December 31, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Cash $ 3,463 $ 3,463 $ — $ — Money market funds 38,336 38,336 — — Restricted cash 260 260 — — $ 42,059 $ 42,059 $ — $ — Liabilities: Derivative liability $ 2,238 $ — $ — $ 2,238 $ 2,238 $ — $ — $ 2,238
Roll-Forward of Fair Value of Derivative Liability	The following table provides a roll-forward of the fair value of the derivative liability (in thousands): Balance at December 31, 2017 $ 2,238 Change in fair value of derivative liability, recorded as interest expense (175 ) Balance at September 30, 2018 $ 2,063

Supplemental Balance Sheet In_2

Supplemental Balance Sheet Information (Tables)	9 Months Ended
	Sep. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Schedule of Inventory	Inventories are stated at the lower of cost or net realizable value on a first-in, first-out basis and are comprised of the following (in thousands): September 30, 2018 December 31, 2017 Raw materials $ 715 $ 539 Work-in-process 2,069 562 Finished goods 553 243 Total inventories, net $ 3,337 $ 1,344
Schedule of Property and Equipment	Property and equipment consists of the following (in thousands): September 30, 2018 December 31, 2017 Office and computer equipment $ 409 $ 409 Software 751 743 Laboratory equipment 4,390 4,224 Furniture 200 200 Manufacturing equipment 695 910 Manufacturing tooling and molds 576 255 T2-owned instruments and components 6,758 7,370 Leasehold improvements 3,437 3,437 Construction in progress 1,701 1,591 18,917 19,139 Less accumulated depreciation and amortization (10,727 ) (9,124 ) Property and equipment, net $ 8,190 $ 10,015
Components of Accrued Expenses	Accrued expenses consist of the following (in thousands): September 30, 2018 December 31, 2017 Accrued payroll and compensation $ 3,077 $ 2,793 Accrued research and development expenses 189 818 Accrued professional services 566 1,018 Other accrued expenses 595 1,589 Total accrued expenses and other current liabilities $ 4,427 $ 6,218

Notes Payable (Tables)

Notes Payable (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Schedule of Debt	Future principal payments on the notes payable are as follows (in thousands): September 30, 2018 December 31, 2017 Term loan agreement, net of deferred issuance costs of $1.9 million and $2.4 million, respectively $ 40,869 $ 39,228 Equipment lease credit facility, net of deferred issuance cost of $9 thousand and $24 thousand, respectively 1,399 2,476 Total notes payable 42,268 41,704 Less: current portion of notes payable (3,399 ) (40,696 ) Notes payable, net of current portion $ 38,869 $ 1,008

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	The following is a summary of stock option activity under the Plans (in thousands, except share and per share amounts): Number of Shares Weighted-Average Exercise Price Per Share Weighted-Average Remaining Contractual Term (In years) Aggregate Intrinsic Value Outstanding at December 31, 2017 3,785,083 $ 7.31 6.88 $ 1,989 Granted 1,542,250 5.66 Exercised (395,245 ) 3.90 1,294 Forfeited (595,291 ) 6.46 Cancelled (100,202 ) 13.73 Outstanding at September 30, 2018 4,236,595 6.99 7.17 8,570 Exercisable at September 30, 2018 2,308,545 7.74 5.59 5,222 Vested or expected to vest at September 30, 2018 3,775,876 7.14 6.92 7,731
Schedule of Estimated Assumptions Used to Calculate Weighted-Average Grant Date Fair Value of Options Granted	The weighted-average grant date fair values of stock options granted in the nine month periods ended September 30, 2018 and 2017 were $3.55 per share and $3.04 per share, respectively, and were calculated using the following estimated assumptions: Nine Months Ended September 30, 2018 2017 Weighted-average risk-free interest rate 2.66 % 1.98 % Expected dividend yield — % — % Expected volatility 68 % 63 % Expected terms 6.0 years 6.0 years
Schedule of Nonvested Restricted Stock Units Activity	The following is a summary of restricted stock unit activity under the 2014 Plan (in thousands, except share and per share amounts): Number of Shares Weighted-Average Grant Date Fair Value Nonvested at December 31, 2017 606,497 5.23 Granted 1,217,190 5.06 Vested (546,547 ) 5.33 Forfeited (75,017 ) 5.63 Cancelled — — Nonvested at September 30, 2018 1,202,123 4.99
Summary of Stock-Based Compensation Expense for Stock Options Granted that was Recorded in the Company's Results of Operations	The following table summarizes the stock-based compensation expense resulting from awards granted under stock incentive plans, including the 2014 ESPP, that was recorded in the Company’s results of operations for the periods presented (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Cost of product revenue $ 23 $ 18 $ 408 $ 87 Research and development 409 340 1,271 1,047 Selling, general and administrative 1,601 862 5,561 2,555 Total stock-based compensation expense $ 2,033 $ 1,220 $ 7,240 $ 3,689

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following shares were excluded from the calculation of diluted net loss per share applicable to common stockholders, prior to the application of the treasury stock method, because their effect would have been anti-dilutive for the periods presented: Three and Nine Months Ended September 30, 2018 2017 Options to purchase common shares 4,236,595 3,833,300 Restricted stock units 1,202,123 750,320 Warrants to purchase common stock 528,958 528,958 Total 5,967,676 5,112,578

Nature of Business - Additional

Nature of Business - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 04, 2018	Sep. 30, 2018	Dec. 31, 2017
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Cash and cash equivalents		$ 60,225	$ 41,799
Accumulated deficit		(302,022)	$ (266,117)
Secondary Offering [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Net proceeds from private investment in public equity	$ 49,200
Co Development Partnership Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds received for achievement of milestone		$ 2,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended	9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2018USD ($)Segment	Dec. 31, 2017USD ($)
Product Information [Line Items]
Number of operating segments | Segment		1
Aggregate amount of transaction price allocated to remaining performance obligations for contracts with original duration greater than one year	$ 3,800,000	$ 3,800,000
Remaining performance obligation, expected timing of satisfaction		The Company expects to recognize revenue on the remaining performance obligations over the next 2 years.
Contract assets	900,000	$ 900,000	$ 0
Contract liabilities	700,000	700,000	$ 1,700,000
Revenue recognized relating to contract liabilities	0	1,700,000
Costs to obtain or fulfill contract capitalized	0	$ 0
Minimum [Member]
Product Information [Line Items]
Aggregate amount of transaction price allocated to remaining performance obligations, original duration		1 year
Maximum [Member]
Product Information [Line Items]
Original expected period of contracts for which value of unsatisfied performance obligations not to be disclosed		1 year
T2 Dx [Member]
Product Information [Line Items]
Maintenance Services period (in years)		1 year
Additional period for Maintenance Service option (in years)		1 year
Accounting Standards Update 2014-09 [Member]
Product Information [Line Items]
Impact of ASC 606 on revenue	$ 100,000	$ 300,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Disaggregation of Revenue by Major Resource (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation Of Revenue [Line Items]
Revenue	$ 2,466	$ 1,108	$ 8,708	$ 3,005
Product Instruments [Member]
Disaggregation Of Revenue [Line Items]
Revenue	504		1,213
Total Product Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	1,218	739	3,486	2,105
Product Consumables [Member]
Disaggregation Of Revenue [Line Items]
Revenue	608		1,929
Research [Member]
Disaggregation Of Revenue [Line Items]
Revenue	1,248	$ 369	5,222	$ 900
Instrument Rentals [Member]
Disaggregation Of Revenue [Line Items]
Revenue	$ 106		$ 344

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities at Fair value on a Recurring Basis (Detail) - Estimate of Fair Value Measurement [Member] - Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Assets:
Restricted cash	$ 180	$ 260
Total assets	60,405	42,059
Liabilities:
Derivative liability	2,063	2,238
Total Liabilities	2,063	2,238
Cash [Member]
Assets:
Cash	1,508	3,463
Money Market Funds [Member]
Assets:
Cash	58,717	38,336
Level 1 [Member]
Assets:
Restricted cash	180	260
Total assets	60,405	42,059
Level 1 [Member] | Cash [Member]
Assets:
Cash	1,508	3,463
Level 1 [Member] | Money Market Funds [Member]
Assets:
Cash	58,717	38,336
Level 3 [Member]
Liabilities:
Derivative liability	2,063	2,238
Total Liabilities	$ 2,063	$ 2,238

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - CRG [Member] - Term Loan Agreement [Member] - USD ($) $ in Millions	1 Months Ended		9 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2016	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Additional interest rate, event of default (as a percent)	4.00%	4.00%	4.00%
Derivative liability			$ 2.1	$ 2.2
Line of credit, additional borrowing capacity	$ 10	$ 10
Debt instrument covenant compliance revenue targeted for fiscal year	$ 7		$ 7
FDA approval by April 30, 2018 [Member] | Measurement Input, Discount Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value of discount rate				40.00%
FDA approval After April 30, 2018 [Member] | Measurement Input, Discount Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value of discount rate				20.00%
No FDA approval [Member] | Measurement Input, Discount Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value of discount rate				40.00%
Contingent Interest Beginning in 2020 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent payment of interest rate			4.00%
Contingent Interest Beginning in 2020 [Member] | Measurement Input, Discount Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value of discount rate			70.00%
Contingent Interest Beginning in 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent payment of interest rate			4.00%
Contingent Interest Beginning in 2021 | Measurement Input, Discount Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value of discount rate			30.00%

Fair Value Measurements - Roll-

Fair Value Measurements - Roll-Forward of Fair Value of Derivative Liability (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Change in fair value of derivative liability, recorded as interest expense	$ (175)
Probability-Weighted Discounted Cash Flow Model [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance at December 31, 2017	2,238
Change in fair value of derivative liability, recorded as interest expense	(175)
Balance at September 30, 2018	$ 2,063

Restricted Cash - Additional In

Restricted Cash - Additional Information (Detail) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Restricted Cash And Cash Equivalents Items [Line Items]
Unrestricted cash	$ 60,225,000	$ 41,799,000
Certificates of deposit [Member]
Restricted Cash And Cash Equivalents Items [Line Items]
Security deposit	180,000	$ 260,000
Unrestricted cash	$ 80,000

Supplemental Balance Sheet In_3

Supplemental Balance Sheet Information - Schedule of Inventory (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Raw materials	$ 715	$ 539
Work-in-process	2,069	562
Finished goods	553	243
Total inventories, net	$ 3,337	$ 1,344

Supplemental Balance Sheet In_4

Supplemental Balance Sheet Information - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 18,917	$ 19,139
Less accumulated depreciation and amortization	(10,727)	(9,124)
Property and equipment, net	8,190	10,015
Office and Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	409	409
Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	751	743
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	4,390	4,224
Furniture [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	200	200
Manufacturing Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	695	910
Manufacturing Tooling and Molds [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	576	255
T2-Owned Instruments and Components [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	6,758	7,370
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,437	3,437
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,701	$ 1,591

Supplemental Balance Sheet In_5

Supplemental Balance Sheet Information - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Supplemental Balance Sheet Information [Line Items]
Raw materials and work-in-process inventory	$ 0		$ 0		$ 800,000
Transfer from other liabilities to accrued expenses and other current liabilities related to fee from debt					$ 600,000
T2 Owned Instruments in Service [Member]
Supplemental Balance Sheet Information [Line Items]
Estimated useful lives (in years)	5 years
T2 Owned Instruments in Service [Member] | Product [Member]
Supplemental Balance Sheet Information [Line Items]
Depreciation expense recorded as a component of cost of product revenue	$ 200,000	$ 200,000	700,000	$ 700,000
T2-Owned Instruments and Components [Member]
Supplemental Balance Sheet Information [Line Items]
Impairment charges			2,600,000
T2 Candida 1.0 Cartridge [Member]
Supplemental Balance Sheet Information [Line Items]
Impairment charges			$ 200,000

Supplemental Balance Sheet In_6

Supplemental Balance Sheet Information - Components of Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accrued Liabilities Current [Abstract]
Accrued payroll and compensation	$ 3,077	$ 2,793
Accrued research and development expenses	189	818
Accrued professional services	566	1,018
Other accrued expenses	595	1,589
Total accrued expenses and other current liabilities	$ 4,427	$ 6,218

Notes Payable - Schedule of Deb

Notes Payable - Schedule of Debt (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument
Total notes payable	$ 42,268	$ 41,704
Less: current portion of notes payable	(3,399)	(40,696)
Notes payable, net of current portion	38,869	1,008
Medium-term Notes [Member] | Term Loan Agreement [Member]
Debt Instrument
Total notes payable	40,869	39,228
Line of Credit [Member] | Equipment Lease Credit Facility [Member]
Debt Instrument
Total notes payable	$ 1,399	$ 2,476

Notes Payable - Schedule of D_2

Notes Payable - Schedule of Debt (Parenthetical) (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Term Loan Agreement [Member] | Medium-term Notes [Member]
Debt Instrument
Deferred issuance costs	$ 1,900	$ 2,400
Equipment Lease Credit Facility [Member] | Line of Credit [Member]
Debt Instrument
Deferred issuance costs	$ 9	$ 24

Notes Payable - Term Loan Agree

Notes Payable - Term Loan Agreement - Additional Information (Detail) $ / shares in Units, $ in Thousands	1 Months Ended		9 Months Ended
	Mar. 31, 2018USD ($)	Dec. 31, 2016USD ($)Warrant$ / sharesshares	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Debt Instrument
Current notes payable in anticipation of accelerated principal payments			$ 2,000
Repayments of note payable			1,094	$ 898
Common Stock [Member]
Debt Instrument
Number of warrants | Warrant		4
Number of shares issuable for warrants outstanding (in shares) | shares		528,958
Exercise price of warrants | $ / shares		$ 8.06
Fair market value of warrants		$ 1,800
Loan and Security Agreement [Member]
Debt Instrument
Repayments of note payable		28,000
CRG [Member] | Term Loan Agreement [Member]
Debt Instrument
Debt instrument, required payment in December 31, 2021			23,200
Debt instrument, required payment in December 31, 2022			23,200
Proceeds from issuance of long-term debt		40,000
Line of credit, additional borrowing capacity	$ 10,000	$ 10,000
Debt term (in years)		6 years
Debt instrument, term of interest-only payments (in years)		3 years
Debt instrument, extended term interest only payments (in years)		4 years
Final fee as a percentage of the principal outstanding (as a percent)		8.00%
Debt instrument, prepayment fee term (in years)		5 years
Debt instrument covenant compliance revenue targeted for fiscal year 2018	$ 7,000		$ 7,000
Additional interest rate, event of default (as a percent)	4.00%	4.00%	4.00%
Derivative liability			$ 2,100		$ 2,200
Proceeds from issuance of note payable, net		$ 39,200
Portion of proceeds used for debt repayment		$ 28,000
CRG [Member] | Term Loan Agreement [Member] | Prior to Approval Milestone [Member]
Debt Instrument
Annual fixed rate (as a percent)		12.50%
Deferred interest rate (as a percent)		4.00%
CRG [Member] | Term Loan Agreement [Member] | Following Approval Milestone [Member]
Debt Instrument
Annual fixed rate (as a percent)		11.50%
Deferred interest rate (as a percent)		3.50%

Notes Payable - Equipment Lease

Notes Payable - Equipment Lease Credit Facility - Additional Information (Detail) - Capital Lease Obligations [Member]	1 Months Ended
	Jun. 30, 2016USD ($)Draw	Apr. 30, 2016USD ($)	Oct. 31, 2015USD ($)
Debt Instrument
Initial borrowing capacity			$ 10,000,000
Maximum borrowings available (up to)			$ 5,000,000
Debt term (in months)			36 months
Repurchase price as percentage of original equipment value that the equipment under lease may be repurchased by lessee			10.00%
Minimum lease period to extend lease (in years)			1 year
Amount of draw	$ 2,500,000	$ 2,100,000
Amount of monthly payment	$ 79,000	$ 67,000
Number of draws | Draw	2

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Jun. 04, 2018	Sep. 15, 2017	Sep. 21, 2016	Sep. 30, 2018	Dec. 31, 2017
Class Of Stock [Line Items]
Common stock, shares authorized				200,000,000	200,000,000
Common stock, par value (in dollars per share)				$ 0.001	$ 0.001
Common stock, shares outstanding				44,038,754	35,948,900
Private Placement [Member] | Canon U S A Inc
Class Of Stock [Line Items]
Number of shares sold			6,055,341
Sale price of stock (in dollars per share)			$ 6.56
Proceeds from issuance of common stock			$ 39.7
Percentage of common shares outstanding (as a percentage)			19.90%
Public Offering [Member]
Class Of Stock [Line Items]
Number of shares sold	7,015,000	5,031,250
Sale price of stock (in dollars per share)	$ 7.50	$ 4
Proceeds from issuance of common stock	$ 52.6	$ 20.1
Proceeds from issuance of common stock after underwriters discount and expenses	$ 49.2	$ 18.8

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Mar. 31, 2018	Dec. 31, 2017
Share-Based Compensation
Fair value of vested stock options			$ 2,300	$ 3,500
Stock-based compensation expense	$ 2,033	$ 1,220	7,240	3,689
T2Dx Instruments and Components [Member]
Share-Based Compensation
Stock-based compensation expense	200	$ 0	$ 300	100
Performance-based awards [Member]
Share-Based Compensation
Outstanding, end of the period						106,066
Forfeited performance stock based options			106,066
Restricted Stock Units [Member]
Share-Based Compensation
Weighted-average period			7 months 28 days
Restricted stock units granted			1,217,190
Restricted stock units vested			546,547
Shares for withheld to cover employee tax			14,803
Unrecognized compensation cost related to unvested stock options	$ 3,200		$ 3,200
2014 Stock Option Plan [Member] | Stock Options [Member]
Share-Based Compensation
Shares available for future issuance under stock incentive plan	823,529		823,529
Percentage of common shares outstanding	4.00%		4.00%
Shares available for grant	755,341		755,341
Inducement Plan [Member]
Share-Based Compensation
Shares available for grant	262,750		262,750
Shares available for authorization					625,000
2006 and 2014 Stock Option Plans [Member] | Stock Options [Member]
Share-Based Compensation
Aggregate fair value of options granted			$ 5,500	$ 2,500
Outstanding, end of the period	4,236,595		4,236,595			3,785,083
Forfeited performance stock based options			595,291
Weighted average fair value of options granted			$ 3.55	$ 3.04
Unrecognized compensation cost related to unvested stock options	$ 6,800		$ 6,800
Weighted-average period			2 years 10 months 24 days
2006 and 2014 Stock Option Plans [Member] | Restricted Stock Units [Member]
Share-Based Compensation
Aggregate fair value of restricted stock units granted			$ 6,200
Restricted stock units granted			1,179,090
Restricted stock units vested			294,775
2006 and 2014 Stock Option Plans [Member] | Restricted Stock Units with Market Condition [Member]
Share-Based Compensation
Compensation Cost	$ 900		$ 3,600
Maximum [Member] | 2006 Stock Option Plan [Member] | Stock Options [Member]
Share-Based Compensation
Expiration period			10 years
Vesting period			4 years
Maximum [Member] | 2014 Stock Option Plan [Member] | Stock Options [Member]
Share-Based Compensation
Expiration period			10 years
Vesting period			4 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Detail) - 2006 and 2014 Stock Option Plans [Member] - Stock Options [Member] - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Share-Based Compensation
Number of Shares Outstanding, beginning of the period	3,785,083
Number of Shares, Granted	1,542,250
Number of Shares, Exercised	(395,245)
Number of Shares, Forfeited	(595,291)
Number of Shares, Cancelled	(100,202)
Number of Shares Outstanding, end of the period	4,236,595	3,785,083
Number of Shares, Exercisable	2,308,545
Number of Shares, Vested or expected to vest	3,775,876
Weighted-Average Exercise Price Per Share Outstanding, beginning of the period	$ 7.31
Weighted-Average Exercise Price Per Share, Granted	5.66
Weighted-Average Exercise Price Per Share, Exercised	3.90
Weighted-Average Exercise Price Per Share, Forfeited	6.46
Weighted-Average Exercise Price Per Share, Cancelled	13.73
Weighted-Average Exercise Price Per Share Outstanding, end of the period	6.99	$ 7.31
Weighted-Average Exercise Price Per Share, Exercisable	7.74
Weighted-Average Exercise Price Per Share, Vested or expected to vest	$ 7.14
Weighted-Average Remaining Contractual Term, Outstanding	7 years 2 months 1 day	6 years 10 months 17 days
Weighted-Average Remaining Contractual Term, Exercisable	5 years 7 months 2 days
Weighted-Average Remaining Contractual Term, Vested or expected to vest	6 years 11 months 1 day
Aggregate Intrinsic Value, Outstanding	$ 8,570	$ 1,989
Aggregate Intrinsic Value, Exercised	1,294
Aggregate Intrinsic Value, Exercisable	5,222
Aggregate Intrinsic Value, Vested or expected to vest	$ 7,731

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Estimated Assumptions Used to Calculate Weighted-Average Grant Date Fair Value of Options Granted (Detail) - Stock Options [Member] - 2006 and 2014 Stock Option Plans [Member]	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Share-Based Compensation
Weighted-average risk-free interest rate	2.66%	1.98%
Expected dividend yield	0.00%	0.00%
Expected volatility	68.00%	63.00%
Expected terms	6 years	6 years

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of Nonvested Restricted Stock Units Activity (Detail) - Restricted Stock Units [Member]	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Share-Based Compensation
Number of Shares, Nonvested restricted shares at the beginning of the period | shares	606,497
Number of Shares, Restricted shares granted | shares	1,217,190
Number of Shares, Restricted shares vested | shares	(546,547)
Number of Shares, Restricted shares forfeited | shares	(75,017)
Number of Shares, Cancelled | shares	0
Number of Shares, Nonvested restricted shares at the end of the period | shares	1,202,123
Weighted-Average Grant Date Fair Value, Nonvested restricted shares at the beginning of the period | $ / shares	$ 5.23
Weighted-Average Grant Date Fair Value, Granted | $ / shares	5.06
Weighted-Average Grant Date Fair Value, Vested | $ / shares	5.33
Weighted-Average Grant Date Fair Value, Forfeited | $ / shares	5.63
Weighted-Average Grant Date Fair Value, Cancelled | $ / shares	0
Weighted-Average Grant Date Fair Value, Nonvested restricted shares at the end of the period | $ / shares	$ 4.99

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock-Based Compensation Expense for Stock Options Granted that was Recorded in the Company's Results of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Stock-based compensation expense
Stock-based compensation expense	$ 2,033	$ 1,220	$ 7,240	$ 3,689
Cost of Product Revenue [Member]
Stock-based compensation expense
Stock-based compensation expense	23	18	408	87
Research and Development [Member]
Stock-based compensation expense
Stock-based compensation expense	409	340	1,271	1,047
Selling, General and Administrative [Member]
Stock-based compensation expense
Stock-based compensation expense	$ 1,601	$ 862	$ 5,561	$ 2,555

Warrants - Additional Informati

Warrants - Additional Information (Detail) - Common Stock [Member] $ / shares in Units, $ in Millions	1 Months Ended
	Dec. 31, 2016USD ($)Warrant$ / sharesshares
Class of Warrant or Right [Line Items]
Number of warrants | Warrant	4
Number of shares issuable for warrants outstanding | shares	528,958
Exercise price of warrants | $ / shares	$ 8.06
Fair market value of warrants | $	$ 1.8

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted net loss per share	5,967,676	5,112,578	5,967,676	5,112,578
Options to Purchase Common Shares [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted net loss per share	4,236,595	3,833,300	4,236,595	3,833,300
Restricted Stock Units [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted net loss per share	1,202,123	750,320	1,202,123	750,320
Warrants to Purchase Common Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from the computation of diluted net loss per share	528,958	528,958	528,958	528,958

Co-Development Agreements - Add

Co-Development Agreements - Additional Information (Detail)	Nov. 01, 2016USD ($)specie	Sep. 21, 2016USD ($)	Feb. 03, 2015USD ($)Item	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)specie	Oct. 31, 2015USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue							$ 2,466,000	$ 1,108,000	$ 8,708,000	$ 3,005,000
Co Development Partnership Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds received for achievement of milestone									2,000,000
Co Development Partnership Agreement [Member] | Canon U.S. Life Sciences Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront payment			$ 2,000,000
Additional consideration receivable upon achievement of certain development and regulatory milestones			6,500,000
Aggregate consideration receivable			$ 8,500,000
Proceeds received for achievement of milestone				$ 2,000,000		$ 1,500,000
Additional consideration receivable upon achievement of additional development and regulatory milestone							3,000,000		3,000,000
Number of units | Item			1
Revenue							200,000	0	1,500,000	300,000
Co Development Partnership Agreement [Member] | Allergan Sales [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront payment	$ 2,000,000
Aggregate consideration receivable	$ 4,000,000
Revenue							700,000	$ 400,000	2,900,000	$ 600,000
Number of additional bacteria species added to existing product candidate | specie	1
Co Development Partnership Agreement [Member] | CARB-X [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue							$ 400,000		$ 900,000
Number of additional bacteria species added to existing product candidate | specie					20
Co Development Partnership Agreement [Member] | CARB-X [Member] | Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Aggregate consideration receivable					$ 2,000,000
Collaborative arrangement reimbursement amount					1,100,000
Milestone payment					$ 900,000
Private Placement [Member] | Canon U S A Inc
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from sale of shares in related party		$ 39,700,000
Percentage of outstanding shares at date of sale		19.90%