Albireo Pharma (ALBO) 10-K 27 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Mar. 01, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Entity Registrant Name	Albireo Pharma, Inc.
Entity Central Index Key	1,322,505
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	ALBO
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 140
Entity Common Stock, Shares Outstanding		11,897,146

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 53,231	$ 29,931
Prepaid expenses and other assets	1,054	560
Other receivables	726	370
Total current assets	55,011	30,861
Equipment, net	178	21
Intangible assets		150
Goodwill	17,260	18,110
Other noncurrent assets	775	518
Total assets	73,224	49,660
Current liabilities:
Trade payables	1,350	972
Accrued expenses	6,105	7,548
Long-term debt, current portion		3,075
Warrants liability		844
Other liabilities	474	269
Total current liabilities	7,929	12,708
Other long-term liabilities	42
Total liabilities	7,971	12,708
Stockholders’ equity (deficit):
Common stock, $0.01 par value per share — 30,000,000 and 200,000,000 authorized at December 31, 2017 and December 31, 2016; 8,902,784 and 6,292,644 issued and outstanding at December 31, 2017 and December 31, 2016	89	63
Additional paid in capital	114,522	61,338
Accumulated other comprehensive income	1,001	1,496
Accumulated deficit	(50,359)	(25,945)
Total stockholders’ equity (deficit)	65,253	36,952
Total liabilities, convertible preference shares and stockholders’ equity	$ 73,224	$ 49,660

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	30,000,000	200,000,000
Common stock, shares issued	8,902,784	6,292,644
Common stock, shares outstanding	8,902,784	6,292,644

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Revenue	$ 1	$ 11,364
Operating expenses:
Research and development	12,991	8,077
General and administrative	15,246	15,786
Other (income) expense, net	(3,659)	(205)
Total operating expenses	24,578	23,658
Operating loss	(24,577)	(12,294)
Interest income (expense), net	40	(1,319)
Non-operating income (expense), net	335	(2,675)
Net loss before income taxes	(24,202)	(16,288)
Income tax	212	62
Net loss	$ (24,414)	$ (16,350)
Net loss per share attributable to holders of common stock:
Basic and diluted	$ (3.12)	$ (13.19)
Weighted-average shares outstanding:
Basic and diluted	7,819,302	1,239,694

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (24,414)	$ (16,350)
Other comprehensive income:
Foreign currency translation adjustment	(495)	692
Total other comprehensive (loss) income	(495)	692
Total comprehensive loss	$ (24,909)	$ (15,658)

Consolidated Statements of Conv

Consolidated Statements of Convertible Preference Shares and Shareholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Convertible Preference Shares	Ordinary Shares	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Convertible Preference Shares at Dec. 31, 2015		$ 520
Convertible Preference Shares (in shares) at Dec. 31, 2015		39,354,000
Balance—December 31, 2015 at Dec. 31, 2015	$ (8,741)		$ 50			$ 804	$ (9,595)
Balance (in shares) at Dec. 31, 2015			265,560
Issuance of Ordinary A shares	40		$ 6		$ 34
Issuance of Ordinary A shares (in shares)			42,726
Issuance of warrants	39				39
Issuance of Series C preference shares		$ 9,655
Issuance of Series C preference shares (in Shares)		9,708,740
Conversion of 2014 and 2015 conversion loans		$ 8,074
Conversion of 2014 and 2015 conversion loans, shares		5,918,777
Conversion of convertible preference shares and the 2014 and 2015 Convertible Notes to common stock	18,248	$ (18,249)		$ 38	18,210
Conversion of convertible preference shares and the 2014 and 2015 Convertible Notes to common stock, shares		(54,981,517)		3,846,083
Share exchange and adjustment for reverse acquisition	41,886		$ (56)	$ 25	41,917
Share exchange and adjustment for reverse acquisition, shares			(308,286)	2,446,561
Share based compensation expense	1,138				1,138
Other comprehensive loss	692					692
Net loss	(16,350)			$ (16,350)			(16,350)
Balance—December 31, 2016 at Dec. 31, 2016	36,952			$ 63	61,338	1,496	(25,945)
Balance (in shares) at Dec. 31, 2016				6,292,644
Share based compensation expense	3,700				3,700
Exercise of options	$ 385			$ 1	384
Exercise of options, shares	50,309			50,309
Exercise of warrants	$ 617				617
Exercise of warrants, shares				29,831
Issuance of common stock, net of costs	48,508			$ 25	48,483
Issuance of common stock, net of costs, shares				2,530,000
Other comprehensive loss	(495)					(495)
Net loss	(24,414)			$ (24,414)			(24,414)
Balance—December 31, 2016 at Dec. 31, 2017	$ 65,253			$ 89	$ 114,522	$ 1,001	$ (50,359)
Balance (in shares) at Dec. 31, 2017				8,902,784

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net loss	$ (24,414)	$ (16,350)
Adjustments to reconcile net loss to net cash used in operating activities:
Accretion of debt discount and amortization of issuance costs	163	1,065
Depreciation and amortization	35	14
Noncash gain on foreign currency translation	(1,107)
Loss on settlement of 2014 Convertible Loans and 2015 Convertible Loans		2,095
Gain from the sale of IPR&D	(3,500)
Change in fair value of financial instruments	(251)	(13)
Stock-based compensation expense	3,700	1,138
Changes in operating assets and liabilities:
Trade receivables	28	1,246
Prepaid expenses and other current assets	(467)	(214)
Other receivables	(339)	(142)
Other non-current assets	(245)	183
Trade payables	263	(1,164)
Accrued expenses	(1,705)	3,214
Other liabilities	231	144
Other non-current liabilities	42
Net cash used in operating activities	(27,566)	(8,784)
Cash flows from investing activities:
Purchase of property, plant and equipment	(190)	(3)
Cash acquired in business combinations		25,483
Proceeds from sale of property, plant and equipment	4,500
Net cash provided by investing activities	4,310	25,480
Cash flows from financing activities:
Proceeds from issuance of stock	48,508
Proceeds from issuance of warrants, net of issuance costs		39
Proceeds from exercise of stock options	385
Payments of principal on borrowings	(3,055)	(2,157)
Net cash provided by in financing activities	45,838	7,612
Effect of exchange rate changes on cash and cash equivalents	718	503
Net increase in cash and cash equivalents	23,300	24,811
Cash and cash equivalents—beginning of period	29,931	5,120
Cash and cash equivalents—end of period	53,231	29,931
Supplemental disclosures of cash flow information:
Cash paid for interest	178	450
Settlement of derivative liabilities		2,343
Ordinary A Shares
Cash flows from financing activities:
Proceeds from issuance of stock		40
Series C Preference Shares
Cash flows from financing activities:
Proceeds from issuance of Series C preference shares		9,690
2014 and 2015 Convertible Notes
Supplemental disclosures of cash flow information:
Conversion of convertible preference shares and the 2014 and 2015 Convertible Notes to common stock		8,563
Biodel Inc.
Supplemental disclosures of cash flow information:
Shares issued		$ 41,886
Kreos
Supplemental disclosures of cash flow information:
Shares issued	$ 617

Summary of Significant Accounti

Summary of Significant Accounting Policies and Basis of Presentation	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies and Basis of Presentation	1. Summary of significant accounting policies and basis of presentation Organization and Share Exchange Albireo Pharma, Inc. (Parent), together with its direct and indirect subsidiaries (the Company), is a clinical-stage biopharmaceutical company focused on the development and commercialization of novel bile acid modulators to treat orphan pediatric liver diseases and other liver and gastrointestinal diseases and disorders. The Company’s clinical pipeline includes a Phase 3 product candidate, a Phase 2 product candidate, and elobixibat, which is approved in Japan for the treatment of chronic constipation. A4250, the Company’s Phase 3 lead product candidate, is in development initially for the treatment of patients with progressive familial intrahepatic cholestasis (PFIC), a rare, life-threatening genetic disorder affecting young children. Prior to November 3, 2016, Parent’s name was Biodel Inc. (Biodel). On that date, Biodel effected a 1-for-30 reverse stock split of its common stock (Reverse Stock Split) and completed a share exchange transaction with Albireo Limited, a limited company domiciled in London, United Kingdom, in accordance with the terms of an Amended and Restated Share Exchange Agreement (the Share Exchange Agreement), dated as of July 13, 2016, by and among Biodel, Albireo Limited and the shareholders and noteholders of Albireo Limited. Pursuant to the Share Exchange Agreement, each holder of shares or notes convertible into shares of Albireo Limited received newly issued shares of Biodel common stock and Albireo Limited became a wholly owned subsidiary of Biodel (the Biodel Transaction). Following completion of the Biodel Transaction, the business of Albireo Limited became the business of Parent and Parent changed its name to Albireo Pharma, Inc. For accounting purposes, the Biodel Transaction was treated as a “reverse acquisition” and Albireo Limited was considered the accounting acquirer. Accordingly, these Consolidated Financial Statements reflect the historical results of Albireo Limited and its direct and indirect subsidiaries prior to completion of the Biodel Transaction and do not include the historical results of Biodel prior to completion of the Biodel Transaction. See Note 6. Except as provided in Note 9, all 2017 and 2016 share and per share information has been adjusted to reflect the exchange of shares in the Biodel Transaction based on an exchange ratio of 0.06999 and, where applicable, the Reverse Stock Split. Basis of presentation These Consolidated Financial Statements have been prepared in conformity with generally accepted accounting principles in the United States (U.S. GAAP). Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Update (ASU) of the Financial Accounting Standards Board (FASB). Any reference in these Consolidated Financial Statements to common stock or options or warrants to purchase shares of common stock of the Company means the common stock or options or warrants to purchase shares of common stock of Parent. Any reference in these Consolidated Financial Statements to common stock means, for periods prior to November 3, 2016, Ordinary shares of Albireo Limited. Principles of consolidation The accompanying Consolidated Financial Statements include the accounts of Parent and its direct or indirect wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. In the opinion of management, all adjustments (including normal recurring accruals) considered necessary for fair presentation have been included in the Consolidated Financial Statements. Foreign currency translation Functional and presentation currency Items included in the financial statements of each entity comprising the Company are measured using the currency of the primary economic environment in which the entity operates (the functional currency). The functional currency for Parent, Albireo Security Corp. and Albireo, Inc. is the U.S. Dollar (USD), the functional currency for Albireo Limited, Elobix AB and Biodel UK Limited is the Euro, and the functional currency for Albireo AB is the Swedish Krona (SEK). The Company consolidates its financial statements in USD. Transactions and balances Foreign currency transactions in each entity comprising the Company are translated into the functional currency of the entity using the exchange rates prevailing at the dates of the transactions. Foreign exchange gains and losses resulting from the settlement of such transactions and from the translation at year-end exchange rates of monetary assets and liabilities denominated in foreign currencies are recognized within Other income (expense), net in the Consolidated Statements of Operations. The results and financial position of the Company and its subsidiaries that have a functional currency different from the presentation currency are translated into the presentation currency as follows: a. assets and liabilities presented are translated at the closing exchange rate as of December 31, 2017 and 2016; b. income and expenses for the statements of operations and comprehensive loss are translated at average exchange rates that are relevant for the respective periods for which the income and expenses occurred; c. significant transactions use the exchange rate on the date of the transaction; and d. all resulting exchange differences arising from such translation are recognized directly in other comprehensive (loss) income and the cumulative impact is presented in accumulated other comprehensive income as a separate component of equity. Use of estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts of assets, liabilities, revenues and expenses reported in the financial statements and accompanying notes. Management must apply significant judgment in this process. On an ongoing basis, the Company evaluates its estimates and assumptions, including but not limited to accruals, valuation allowances associated with deferred tax assets and, historically, warrant liability, which is estimated at fair value. Actual results could materially differ from these estimates. Segment information The Company’s entire business is managed by a single management team, which reports to the chief executive officer. The chief executive officer is the chief operating decision maker. The Company has determined it has one operating segment as its chief operating decision maker allocates resources and assesses the performance of the business at this level. Accordingly, the Company has one reporting segment, which is the research and development of novel treatments for liver and gastrointestinal diseases and disorders. Cash and cash equivalents The Company considers all short-term highly liquid investments with an original maturity at the date of purchase of three months or less to be cash equivalents. Concentration of risk Credit risk Financial instruments that potentially subject the Company to significant concentration of credit risk consist primarily of cash and cash equivalents. For banks and financial institutions, only independent financial institutions with a high credit rating are utilized. The Company’s current license agreement is with an established and reputable pharmaceutical company and, historically, the Company has not had any material collection risk related to its accounts receivable. Concentration of revenue and accounts receivable The Company generally does not require collateral or other security in support of accounts receivable. Allowances are provided for individual accounts receivable when the Company becomes aware of a customer’s inability to meet its financial obligations, such as in the case of bankruptcy, deterioration in the customer’s operating results or change in financial position. If circumstances related to a customer change, estimates of the recoverability of receivables would be further adjusted. The Company also considers broad factors in evaluating the sufficiency of its allowances for doubtful accounts, including the length of time receivables are past due, significant one-time events, creditworthiness of customers and historical experience. There is no allowance for doubtful accounts as of December 31, 2017 or 2016. Equipment, net Equipment is stated at historical cost less depreciation and consists of computers, furniture and fixtures, and other equipment. Depreciation is computed using a straight-line method over the estimated useful lives. Computers and other equipment purchased for less than $2,000 or the equivalent thereof are expensed immediately. Gains and losses on disposals of equipment are determined by comparing the proceeds with the carrying amount and are recognized within Other income (expense), net in the Consolidated Statements of Operations. Impairment of long-lived assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. In such instances, the recoverability of assets to be held and used is measured first by a comparison of the carrying amount of an asset group to future undiscounted net cash flows expected to be generated by the assets. If such assets are considered to be impaired, an impairment loss would be recognized if the carrying amount of the asset exceeds the fair value of the asset. There were no impairments recorded for the years ended December 31, 2017 and 2016. Research and development expenses Research and development costs are expensed as incurred and include primarily salaries, benefits and other staff-related costs; clinical trial and related clinical manufacturing costs; contract services and other outside costs. The Company’s preclinical studies and clinical trials are performed by third-party contract research organizations (CROs). Some of these expenses are billed monthly for services performed, while others are billed based upon milestones achieved. For preclinical studies, the significant factors used in estimating accruals include the percentage of work completed to date and contract milestones achieved. For clinical trial expenses, the significant factors used in estimating accruals include the number of patients enrolled and percentage of work completed to date or contract milestones achieved. The Company’s estimates are highly dependent upon the timeliness and accuracy of the data provided by the respective CROs regarding the status of the contracted activity, with adjustments made when deemed necessary. Revenue recognition Revenue is generated from the receipt of upfront or license fees, milestone payments and payments for pharmaceutical ingredient or related procurement services that are made pursuant to out-licensing or related supply agreements. Where an out-licensing arrangement of the Company involves the provision of multiple elements that may contain different remuneration arrangements such as upfront payments, milestone payments or product sales, the arrangement is assessed to determine whether separate delivery of the individual elements of such arrangement comprises more than one unit of accounting. The delivered elements are separated if (a) they have value to the licensee on a stand-alone basis, (b) there is objective and reliable evidence of the fair value of the undelivered element(s) and (c) if the arrangement includes a general right of return relative to the delivered element(s), delivery or performance of the undelivered element(s) is considered probable and is substantially in the control of the Company. Allocation of revenue to the different elements that require separate accounting is based on the separate selling prices determined for each component, and total consideration is then allocated pro rata across the components of the arrangement. If separate selling prices are not available, the Company will use its best estimate of such selling prices, consistent with the overall pricing strategy and relevant market factors. The Company has determined that each element of its out-licensing agreements is a separate and distinct unit of accounting, and, as such, the fair value of each element has been subscribed and recognized as follows: • Nonrefundable upfront payments received from the Company’s out-licensing agreements relating to technical expertise and intellectual property are recognized in income if all rights relating to the intellectual property and all obligations resulting from them have been relinquished under the contract terms and the Company has no continuing material obligation to perform under the agreement. However, if rights to the intellectual property continue to exist or obligations resulting from them have yet to be fulfilled, the payments received would be deferred until all rights and obligations have been fulfilled. • Nonrefundable payments that are linked to the achievement of significant and substantive development or regulatory milestones in the research and development process are recognized as revenue upon the achievement of the specified milestone. • Revenue and costs associated with procurement services associated with pharmaceutical ingredients are recognized net in revenue when title and risk of loss of the pharmaceutical ingredients have passed to the licensee as the Company is not the primary obligor, and revenue and costs associated with related procurement services are recognized net in revenue when the Company is contractually bound. As of December 31, 2017, the Company had a license agreement with EA Pharma Co., Ltd. (EA Pharma, formerly Ajinomoto Pharmaceuticals Co., Ltd.), entered into in 2012, to develop a select product candidate (elobixibat) for registration and subsequent commercialization in select markets. The Company satisfied its material performance obligations under the agreement in 2012, upon the delivery of technical expertise and intellectual property rights to EA Pharma. Payments resulting from pharmaceutical ingredient or related procurement services are recognized as revenue as the activities are performed and are presented on a net basis. Revenue is recorded on a net basis because the Company acts as an agent, as it does not have discretion to change suppliers and does not perform any part of the services or manufacture of the subject pharmaceutical ingredients. The costs associated with these activities are netted against the related revenue in the Consolidated Statements of Operations. For certain contingent payments under research and development arrangements, the Company recognizes revenue using the milestone method. Under the milestone method, a payment that is contingent upon the achievement of a substantive milestone is recognized in its entirety in the period in which the milestone is achieved. A milestone is an event: (i) that can be achieved based in whole or in part on either the Company’s performance or on the occurrence of a specific outcome resulting from the Company’s performance, (ii) for which there is substantive uncertainty at the date the arrangement is entered into that the event will be achieved and (iii) that would result in additional payments being due to the Company. The determination that a milestone is substantive requires estimation and judgment and is made at the inception of the arrangement. Milestones are considered substantive when the consideration earned from the achievement of the milestone is: (i) commensurate with either the Company’s performance to achieve the milestone or the enhancement of value of the item delivered as a result of a specific outcome resulting from the Company’s performance to achieve the milestone, (ii) related solely to past performance and (iii) reasonable relative to all deliverables and payment terms in the arrangement. In making the determination as to whether a milestone is substantive or not, management of the Company considers all facts and circumstances relevant to the arrangement, including factors such as the scientific, regulatory, commercial and other risks that must be overcome to achieve the milestone, the level of effort and investment required to achieve the milestone and whether any portion of the milestone consideration is related to future performance or deliverables. The Company has evaluated each milestone specified under its license agreement with EA Pharma and determined the milestone to be substantive. For the year ended December 31, 2017, the Company did not recognize any milestone-based revenue from EA Pharma. For the year ended December 31, 2016, the Company recognized in full into revenue nonrefundable payments of (a) $8.0 million received in April 2016 in connection with a renegotiated payment stream with EA Pharma linked to know-how and intellectual property delivered by the Company upon inception of the license agreement in 2012 and (b) $3.6 million triggered by the decision of EA Pharma to proceed with the preparation of a new drug application for elobixibat in Japan. The renegotiated payment stream was implemented via an amendment to the license agreement that did not change the contingent nature of the remaining deliverables or the parties’ respective obligations under the agreement. Under the terms of the license agreement with EA Pharma, the Company was eligible as of December 31, 2017 to receive up to approximately (a) €13.3 million ($15.9 million based on the Euro to USD exchange rate at December 31, 2017) if specified regulatory events are achieved for elobixibat in Japan and (b) ¥3.5 billion ($31.1 million based on the Japanese Yen to USD exchange rate at December 31, 2017) if specified sales milestones are achieved for elobixibat following regulatory approval in any country in EA Pharma’s licensed territory. Subsequently, in January 2018, the Japanese In December 2017, the Company entered into a royalty interest acquisition agreement, or RIAA, with HealthCare Royalty Partners III, L.P. ( If EA Pharma does not successfully commercialize elobixibat in Japan, the Company may not receive any future payments under its RIAA with HCR or its license agreement with EA Pharma. Stock-based compensation The Company accounts for stock-based compensation awards in accordance with FASB ASC Topic 718, Compensation—Stock Compensation The fair value of the Company’s stock options has been determined using the Black-Scholes option pricing model, which requires the input of subjective assumptions, including (i) the expected stock price volatility, (ii) the expected term of the award, (iii) the risk-free interest rate and (iv) expected dividends. For the years ended December 31, 2017 and December 31, 2016, due to the lack of historical and implied volatility data of the Company’s common stock and equivalents, the expected volatility has been estimated based on the historical volatilities of peer companies in the Company’s industry that are publicly traded. The Company selected companies that it considers to have comparable characteristics to the Company, including enterprise value, risk profiles and position within the industry and with historical share price information sufficient to meet the expected term of the stock options. The historical volatility data has been computed using the daily closing prices for the selected companies. Due to the lack of sufficient historical data, the Company used the “simplified” method, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the award, to determine the expected term of stock options. For periods prior to completion of the Biodel Transaction, the risk-free interest rate for periods within the expected term of the option were based on the United Kingdom Government Bond rate with a maturity date commensurate with the expected term of the associated award. For the periods after completion of the Biodel Transaction, the risk-free interest rate for periods within the expected term of the option is based on the United States Government Bond rate with a maturity date commensurate with the expected term of the associated award. In addition, it is assumed that the Company will not pay dividends in the near future. The Company’s stock-based awards are subject to either service-based or service and performance-based vesting conditions. Prior to the Biodel Transaction, the Company issued certain stock options with exercise prices denominated in a foreign currency (Euro) that were required to be accounted for as liabilities. The Company accounted for liability-classified stock-based awards based on the then-current fair values at each financial reporting date. Changes in the amounts attributed to these awards between the reporting dates were included in the Consolidated Statement of Operations. On November 3, 2016, these stock options were replaced with stock options denominated in USD. The replacement was accounted for as a modification, and the post-modification awards are no longer liability-classified awards. The Company records compensation expense for service-based awards over the vesting period of the award on a straight-line basis. For awards with service and performance based conditions, compensation related to the performance-based vesting conditions is recognized when achievement of the performance condition is considered probable and the compensation expense related to the service condition is recorded using the accelerated method. Modifications to stock-based awards are treated as an exchange of the original award for a new award with total compensation equal to the grant-date fair value of the original award plus any incremental value of the modification. The incremental value is based on the excess of the fair value of the modified award over the fair value of the original award immediately before the modification. Temporary equity The Series A and B preference shares of Albireo Limited prior to completion of the Biodel Transaction are classified outside of Stockholders’ Equity (Deficit) on the basis that the shares were redeemable upon a liquidation event that could be forced by the holders of preference shares through their voting rights on the Albireo Limited Board of Directors. Any undeclared dividends are not recognized until the time it becomes probable that the preference shares will be redeemable. No dividends were recognized for either of the years ended December 31, 2017 or 2016. All preference shares of Albireo Limited were converted into Ordinary shares that were exchanged for shares of common stock of the Company as part of the Biodel Transaction. Employee benefits Pension obligations The Company has defined contribution plans for its Sweden-based employees whereby the Company pays contributions to employee benefit or insurance plans on a mandatory, contractual or voluntary basis. The Company has no legal or constructive obligations to pay further contributions if the fund does not hold sufficient assets to pay all employees the benefits relating to employee service in the current and prior periods. The Company has no further payment obligations once the contributions have been paid. The contributions are recognized as employee benefit expense when they are due. Prepaid contributions are recognized as an asset to the extent that a cash refund or a reduction in the future payments is available. The Company paid $317,000 and $331,000 to the plans for the years ended December 31, 2017 and 2016, respectively. 401(k) The Company has a 401(k) retirement plan in which all U.S.-based employees are eligible to participate. The Company contributed $70,200 and $33,000 to the plan for the years ended December 31, 2017 and 2016, respectively. The Company matches employee contributions to the plan, on a per employee basis, up to 4% of each employee’s wages for the years ended December 31, 2017 and 2016. Loss contingencies Loss contingencies are recorded as liabilities when it is probable that a liability has occurred and the amount of loss is reasonably estimable. Disclosure is required when there is a reasonable possibility that an ultimate loss will be material. Contingent liabilities are often resolved over long periods of time. Estimating probable losses requires analysis that often depends on judgments about potential actions by third parties, such as regulators. Income taxes The Company accounts for income taxes in accordance with ASC 740, Income Taxes Income tax expense consists of taxes currently payable and changes in deferred tax assets and liabilities calculated according to local tax rules. Deferred tax assets and liabilities are based on temporary differences that arise between carrying values used for financial reporting purposes and amounts used for taxation purposes of assets and liabilities and the future tax benefits of tax loss carry forwards. A deferred tax asset is recognized only to the extent that it is more likely than not that future taxable profits will be available against which the asset can be utilized. Significant judgment is required in determining any valuation allowance recorded against deferred tax assets. In assessing the need for a valuation allowance, the Company considers all available evidence for each jurisdiction including past operating results, estimates of future taxable income and the feasibility of ongoing tax planning strategies. In the event that the Company changes its determination as to the amount of deferred tax assets that can be realized, the Company will adjust its valuation allowance with a corresponding impact to income tax expense in the period in which such determination is made. The amount of deferred tax provided is calculated using tax rates in effect at the balance sheet date. The impact of tax law changes is recognized in periods when the change is enacted. A two-step approach is applied pursuant to ASC 740 in the recognition and measurement of uncertain tax positions taken or expected to be taken in a tax return. The first step is to determine if the weight of available evidence indicates that it is more likely than not that the tax position will be sustained in an audit, including resolution of any related appeals or litigation processes. The second step is to measure the tax benefit as the largest amount that is more than 50% likely to be realized upon ultimate settlement. The Company’s policy is to recognize interest and penalty expenses associated with uncertain tax positions as a component of income tax expense in the Consolidated Statements of Operations. As of the years ended December 31, 2017 and 2016, the Company had no accrued interest or penalties related to uncertain tax positions and no amounts have been recognized in the Consolidated Statements of Operations. Net loss per share Basic net loss per share is calculated by dividing the net loss attributable to holders of common stock by the weighted average number of shares of common stock outstanding. Diluted net loss per share is calculated by dividing the net loss attributable to holders of common stock by the weighted-average number of shares of common stock outstanding. If the Company were in a net income position, diluted net income per share would be calculated by dividing the net income attributable to holders of common stock by the weighted-average number of shares of common stock plus dilutive common stock equivalents outstanding, including any dilutive effect from such shares. For the years ended December 31, 2017 and 2016, common stock equivalents included convertible preference shares, stock options and warrants. The Company’s Convertible Loan Notes (see Note 11) were not included in common stock equivalents, as they were not readily convertible at the option of the respective holders. Goodwill and long-lived assets Goodwill is the excess of the purchase price in a business combination over the fair value of identifiable net assets acquired. Goodwill and certain other intangible assets having indefinite lives are not amortized to earnings, but instead are subject to periodic testing for impairment. Goodwill and indefinite-lived intangible assets are assessed at least annually, but also whenever events or changes in circumstances indicate the carrying values may not be recoverable. Factors that could trigger an impairment review, include: (a) significant underperformance relative to historical or projected future operating results; (b) significant changes in the manner of or use of the acquired assets or the strategy for the Company’s overall business; (c) significant negative industry or economic trends; (d) significant decline in the Company’s stock price for a sustained period; and (e) a decline in the Company’s market capitalization below net book value. An entity may assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit, including goodwill, is less than its carrying amount. In evaluating whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, an entity shall assess relevant events and circumstances, both positive and mitigating. An entity shall consider the extent to which each of the adverse events and circumstances identified could affect the comparison of a reporting unit’s fair value with its carrying amount and place more weight on the events and circumstances that most affect a reporting unit’s fair value or the carrying amount of its net assets. If, after assessing the totality of events or circumstances, including those described in the preceding paragraph, an entity determines that it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then the quantitative goodwill impairment test is unnecessary. There are inherent assumptions and estimates used in developing future cash flows requiring management judgment in applying these assumptions, including projecting revenues, interest rates and the cost of capital. Many of the factors used in assessing fair value are outside the Company’s control and it is reasonably likely that assumptions and estimates will change in future periods. These changes can result in future impairments. In the event the Company’s planning assumptions are modified and result in an impairment, the associated expense would be included in the Consolidated Statements of Operations, which could materially impact the Company’s results of operations. The Company conducts an impairment assessment on October 1 each year taking a qualitative evaluation approach to determine if there are any adverse market factors or changes in circumstances indicating that the carrying value of goodwill may not be recoverable. Assessment for possible impairment of long-lived assets is based on the Company’s ability to recover the carrying value of the long-lived asset from the expected future pre-tax cash flows. The expected future pre-tax cash flows are estimated based on historical experience, knowledge and market data. Estimates of future cash flows require the Company to make assumptions and to apply judgment, including forecasting future sales and expenses and estimating the useful lives of assets. If the expected future cash flows related to a long-lived asset are less than the asset’s carrying value, an impairment charge is recognized for the difference between the estimated fair value and the carrying value. Business combination adjustment At the time of the Biodel Transaction in November 2016, the Company preliminarily estimated the fair value of Biodel’s in-process research and development (IPR&D) to be $150,000. Subsequently, the Company continued to evaluate the IPR&D acquired, including the underlying patents, based on information available to the Company as of November 2016. Upon a final evaluation of the IPR&D in 2017, the Company increased the acquisition date value of the IPR&D by $850,000 to $1.0 million and recorded a corresponding reduction to goodwill. In October 2017, the Company entered into an asset purchase agreement pursuant to which it sold IPR&D for $4.5 million, which resulted in a gain recorded in other operating income. Recently adopted accounting pronouncements In March 2016, the FASB issued ASU No. 2016-09, “ Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting In January 2016, the FASB issued ASU No. 2017-04, “ Intangibles—Goodwill and other (Topic 350): Simplifying the test for goodwill impairments Accounting pronouncements issued but not yet adopted

Fair Value Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value of Financial instruments	2. Fair value of financial instruments In measuring fair value, the Company evaluates valuation techniques such as the market approach, the income approach and the cost approach. A three-level valuation hierarchy, which prioritizes the inputs to valuation techniques that are used to measure fair value, is based upon whether such inputs are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect market assumptions made by the reporting entity. The three-level hierarchy for the inputs to valuation techniques is briefly summarized as follows: Level 1—Observable inputs such as quoted prices (unadjusted) for identical Level 2—Observable inputs such as quoted prices for similar Level 3—Unobservable inputs that reflect the reporting entity’s estimate of assumptions that market participants would use in pricing the asset or liability. The following tables present the fair values for the Company’s financial instruments as well as the input levels used to determine these fair values as of December 31, 2017 and 2016. The Company values its current assets, which include trade and other receivables, and liabilities, which include advances from licensees and accounts payable, at historical cost, which approximates fair value. The fair value of the Loan Facility (see Note 11) was $3.4 million as of December 31, 2016. The valuation method used to value the Loan Facility was the income approach. On December 17, 2014, the Company executed a convertible loan instrument, which provided 1,251,000 €1.00 ($1.12) unsecured convertible loan notes (2014 Convertible Loans), denominated in Euros, and was subsequently amended on October 1, 2015. On October 1, 2015, the Company executed a convertible loan instrument which provided 5,000,000 $1.00, unsecured convertible loan notes (the 2015 Convertible Loans), denominated in USD. See Note 11 for a further understanding of these instruments. Immediately prior to completion of the Biodel Transaction on November 3, 2016, the conversion rights for the 2014 and 2015 Convertible Loans were exercised. Total Carrying Value on the Consolidated Balance Sheet Fair Value Measurements Fair Value Level December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 (in thousands) Financial Instruments Recorded at Fair Value on a Recurring Basis Current liabilities: Warrants 3 $ — $ 844 $ — $ 844 Derivative Liabilities Warrants December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 (in thousands) Financial Instruments with a Level 3 measurement Balance, beginning $ — $ 2,047 $ 844 $ 1,163 (Income) loss recognized in earnings — 261 (227 ) (294 ) Purchases, sales, issues and settlements — (2,343 ) (617 ) — Foreign currency (gains) losses — 35 — (25 ) Transfers in (out) — — — — Balance, ending $ — $ — $ — $ 844 There were no transfers from one level to the other during the reporting periods. Warrants In connection with the Loan Facility, the Company issued to Kreos Capital IV (Expert Fund) Limited (Kreos Capital) detachable warrants with a right to acquire shares at €720,000 (the Warrants). The Company recognized the Warrants at fair value at the time of execution of the Loan Facility and remeasured their fair value on a recurring basis thereafter. In connection with the Biodel Transaction, the Warrants were replaced with warrants to purchase 67,271 shares of the Company’s common stock at an exercise price of $11.78 per share (the Replacement Kreos Warrants). The exchange was accounted for as a modification whereby the fair value of the Replacement Kreos Warrants was compared to the fair value of the Warrants immediately before the terms were modified, measured based on the market price of the common stock of the Company and other pertinent factors on the date of the modification. See Note 11 for a further description of the Warrants and Loan Facility. Beginning with the quarter ended June 30, 2016, the Company estimated the fair value of the Warrants, primarily using the binomial method. The revision from December 31, 2015 was due to the execution of the agreement for the Biodel Transaction in 2016. The binomial method used assumptions that were based on the Warrants being exchanged for warrants exercisable for shares of the Company’s common stock. The key assumptions used in the binomial method as of December 31, 2016 included the following: December 31, 2016 Stock price $ 17.73 Exercise price $ 11.78 Term (in years) 1.00 Risk-free interest rate 0.85 % Volatility 83.4 % The fair value of the Replacement Kreos Warrants was determined to be $844,000 (€762,000) as of December 31, 2016. This fair value was classified as a current liability because the Replacement Kreos Warrants were immediately exercisable. On May 10, 2017, Kreos Capital notified the Company of its intent to exercise the Replacement Kreos Warrants on a “cashless” basis. In conjunction with the exercise, the Company remeasured the fair value of the Replacement Kreos Warrants to be $617,000, immediately prior to the exercise. The number of shares of the Company’s common stock issued in the cashless exercise, 29,831 shares, was determined by a formula specified in the warrant document. The existing liability of the fair value at the date of exercise was reclassified to Additional paid in capital. Under the binomial method, the fair value of the Replacement Kreos Warrants decreased by $227,000 and $294,000 for the year ended December 31, 2017 and 2016, respectively.

Equipment, Net

Equipment, Net	12 Months Ended
	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Equipment, Net	3. Equipment, net Equipment, net consisted of the following (in thousands): December 31, 2017 December 31, 2016 Cost: Equipment cost as of January 1, $ 143 $ 142 Additions 190 3 Exchange differences 1 (2 ) Equipment cost as of period end 334 143 Less: Accumulated depreciation as of January 1 (122 ) (108 ) Depreciation for the period (35 ) (12 ) Exchange differences 1 (2 ) Accumulated depreciation as of period end (156 ) (122 ) Total equipment, net $ 178 21 Depreciation expense for the years ended December 31, 2017 and 2016 was $34,000 and $14,000, respectively.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2017
Payables And Accruals [Abstract]
Accrued Expenses	4. Accrued expenses Accrued expenses consisted of the following (in thousands): December 31, 2017 December 31, 2016 Accrued bonuses $ 1,717 $ 849 Accrued vacation pay 464 318 Accrued social security pay 217 1,461 Accrued professional fees 470 730 Accrued development costs 1,747 522 Accrued severance 152 2,864 Accrued other 1,338 804 Total accrued expenses $ 6,105 $ 7,548

Commitments

Commitments	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	5. Commitments and contingencies Operating lease commitments Parent is a party to an Office Lease Agreement with SHIGO 10 PO Owner LLC for approximately 5,116 rentable square feet in the building located at 10 Post Office Square, Boston, Massachusetts, which serves as Parent’s corporate headquarters. The initial term of the lease is 62 months beginning on March 1, 2017. Parent has the option to extend the lease one time for an additional 5-year period. Following an initial two-month rent abatement period, Parent is obligated to make monthly rent payments in an amount that began at $20,997 and escalates by approximately 2% annually for the term of the lease. In addition, Parent is responsible under the lease for specified costs and charges, including certain operating expense, utilities, taxes and insurance. Albireo AB is a party to a 36-month building lease for approximately 5,100 square feet of office space in Gothenburg, Sweden. The lease does not have stated escalating rent clauses, except for changes in the Swedish Consumer Price Index (CPI). The current quarterly payment under the lease is SEK 322,917 ($37,818 based on the SEK to USD exchange rate as of December 31, 2017). The current term of the lease expires in November 2019, but renews automatically thereafter for consecutive three-year terms unless notice of nonrenewal is given by either party at least nine months prior to the end of the current term and subject to Albireo AB’s right to terminate the lease at any time upon six months’ notice. As of December 31, 2017, future minimum commitments under facility operating leases were $1.2 million. Year ended December 31, (in thousands) 2018 331 2019 260 2020 266 2021 271 2022 91 Total Minimum Commitments $ 1,219 Rent expense recognized under the Company’s operating leases was $394,000 and $122,000 for the years ended December 31, 2017 and 2016, respectively. Agreements with CROs As of December 31, 2017, the Company had various agreements with CROs for the conduct of specified research and development activities and, based on the terms of the respective agreements, may be required to make future payments of up to $18.8 million upon the completion of contracted work. Other Commitments In connection with the spin-off from AstraZeneca in 2008 and associated transfer agreements, the Company became party to an assignment agreement between AstraZeneca and a named inventor on a patent related to elobixibat. In connection with this agreement, the inventor is entitled upon the initial launch of a pharmaceutical product that constitutes an IBAT-inhibitor in specified countries, including Japan, to a one-time “launch fee” payment of SEK 4.0 million ($487,000, based on the SEK to USD exchange rate at December 31, 2017).

Business Combination

Business Combination	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Business Combination	6. Business Combination On November 3, 2016, the Company completed the Biodel Transaction pursuant to the Share Exchange Agreement. Subsequent to the Biodel Transaction, the Company is under the leadership of the former management team of Albireo Limited and its board of directors was comprised of two former directors of Biodel and five former directors of Albireo Limited. In the Biodel Transaction, Biodel issued to the former holders of shares of Albireo Limited an aggregate of 4,154,369 shares of Biodel common stock, representing approximately two-thirds of the combined organization’s common stock outstanding at the completion of the Biodel Transaction. The number of shares of Biodel common stock issued was determined based on a negotiated exchange ratio of 0.06999. In addition, in accordance with the terms of the Share Exchange Agreement, all outstanding options or warrants to purchase Albireo Limited shares immediately prior to the Biodel Transaction were converted into options to purchase 351,550 shares of Biodel common stock. The Biodel Transaction was accounted for as a “reverse acquisition” pursuant to which Albireo Limited was considered the accounting acquirer. As such, these Consolidated Financial Statements reflect the historical results of Albireo Limited prior to completion of the Biodel Transaction and do not include the historical results of Biodel prior to completion of the Biodel Transaction. Transaction Costs The Company incurred costs related to the Biodel Transaction, which were expensed in the period ended December 31, 2016. The expensed transaction costs include: (in thousands) Legal fees 1,187 Accounting fees 653 Advisory fees 2,031 Termination and severance 1,749 Total Transaction Costs $ 5,620 In addition to the Biodel Transaction-related costs described above, the Company also recorded general and administrative expense of $1.2 million for the period ended December 31, 2016 associated with a lease termination payment obligation incurred for Biodel’s corporate offices in Danbury, Connecticut. Purchase Consideration and Net Assets Acquired The fair value of Biodel common stock used in determining the purchase price was $19.50 per share, the closing price on November 3, 2016. The acquisition-date fair value of the outstanding stock options of Biodel is included in the purchase consideration based on the amount attributable to services provided by the Biodel employees prior to the Biodel Transaction, calculated using the Black-Scholes option pricing model. In accordance with the change of control provisions, all Biodel options vested on November 3, 2016. Assumptions used in Black-Scholes calculations during such periods included: volatility ranging from 75.7% to 79.0%; risk-free interest rates ranging between 0.64% and 0.72%; and the expected terms ranging from 1.0 to 1.5 years. The purchase price is as follows: (in thousands) Fair value of Biodel shares outstanding $ 41,696 Fair value of Biodel stock options 242 Purchase price $ 41,938 The following presents the final allocation of the purchase consideration to the assets acquired and liabilities assumed as of the acquisition date: (in thousands) Cash and cash equivalents $ 25,483 Other current assets 701 Intangible assets 1,000 Goodwill 17,260 Accounts payable and accrued liabilities (2,215 ) Other current liabilities (286 ) Warrant liabilities (5 ) Total net assets acquired $ 41,938 The amount allocated to in-process research and development represents an estimate of the fair value of purchased in-process technology for research projects (IPR&D), primarily related to Biodel’s glucagon emergency management product candidate and BIOD-531 concentrated prandial/basal insulin combination product candidate. IPR&D is considered an indefinite-lived intangible asset until the completion or abandonment of the associated research and development efforts. Accordingly, during the development period, the IPR&D is not amortized but subject to impairment review. No amortization of the IPR&D has been reflected in these Consolidated Financial Statements as the assets are considered indefinite-lived. The excess purchase consideration over the fair values of assets acquired and liabilities assumed is recorded as goodwill. Goodwill is not amortized but tested for impairment on an annual basis or when an indicator for impairment exists. The goodwill recorded is not tax deductible since the Biodel Transaction was structured as a tax-free exchange. The following table summarizes the Company’s goodwill activity: (in thousands) Goodwill at January 1, 2016 $ — Goodwill resulting from share exchange 18,110 Goodwill at December 31, 2016 $ 18,110 Purchasing accounting adjustment (850 ) Goodwill at December 31, 2017 $ 17,260

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Net Loss Per Share	7. Net loss per share Basic net loss per share, or Basic EPS, is calculated by dividing the net loss attributable to holders of common stock by the weighted average number of shares of common stock outstanding. Diluted net loss per share, or Diluted EPS, is calculated by dividing the net loss attributable to holders of common stock by the weighted-average number of common stock outstanding. If the Company were in a net income position, Diluted EPS would be calculated by dividing the net income attributable to holders of common stock by the weighted-average number of common stock plus dilutive common stock equivalents outstanding. The following table sets forth the computation of Basic EPS and Diluted EPS (in thousands, except for share and per share data): Year Ended December 31, 2017 2016 Basic and Diluted EPS: Numerator Net loss $ (24,414 ) $ (16,350 ) Net loss attributable to holders of common stock $ (24,414 ) $ (16,350 ) Denominator Weighted average number of shares 7,819,302 1,239,694 Number of shares used for basic and diluted EPS computation 7,819,302 1,239,694 Basic and Diluted EPS $ (3.12 ) $ (13.19 ) The following weighted-average outstanding common stock equivalents were excluded from the computation of Diluted EPS for the periods presented because including them would have been anti-dilutive: Year Ended December 31, 2017 2016 Convertible preference shares (on an as-converted basis) — 2,317,898 Warrants to purchase convertible preference shares (on an as-converted basis) — 6,946 Kreos Warrants to purchase common stock — 67,271 Options to purchase to common stock 889,934 390,155

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income taxes	8. Income taxes Effects of the Tax Cuts and Job Act On December 22, 2017, The Tax Cuts and Job Act (the Tax Act) was signed into U.S. law. The Tax Act significantly changes the Internal Revenue Code of 1986, as amended (the Code). Changes under the new tax law include a reduction in the federal corporate tax rate from 34% to 21%, limitations or eliminations to certain tax deductions, and usage of tax benefits in the future. The Company has re-measured its assets and liabilities associated with such future tax benefits in the current year and recognized a decrease in its deferred tax asset of $939,000. This reduction in the deferred tax asset has been offset by a coinciding reduction in the associated valuation allowance, resulting in no net impact. The U.S. Securities and Exchange Commission issued Staff Accounting Bulletin No. 118 (SAB 118), which allows registrants to record provisional amounts during a one year "measurement period" similar to that used when accounting for business combinations. However, the measurement period is deemed to have ended earlier when the registrant has obtained, prepared and analyzed the information necessary to finalize its accounting. During the measurement period, impacts of the law are expected to be recorded at the time a reasonable estimate for all or a portion of the effects can be made, and provisional amounts can be recognized and adjusted as information becomes available, prepared or analyzed. SAB 118 summarizes a three-step process to be applied at each reporting period to account for and disclose: (1) the effects of the change in tax law for which accounting is complete; (2) provisional amounts (or adjustments to provisional amounts) for the effects of the change in tax law where accounting is not complete, but a reasonable estimate has been determined; and (3) current or deferred tax amounts reflected in accordance with law prior to the enactment of the change in tax law because the accounting of the effects of the change in tax law are not complete and a reasonable estimate has not been determined, together with qualitative disclosure of the effects of the changes in tax law for which the accounting is not compete, the reason why the accounting is not complete, and the additional information that is needed to be obtained, prepared or analyzed in order to complete the accounting. As the Tax Act was passed late in 2017 and ongoing guidance and accounting interpretation is expected over the next 12 months, the Company considers the accounting to be preliminary due to the forthcoming guidance and its ongoing analysis of final year-end data and tax positions. Adjustments to these preliminary amounts identified during the measurement period will be included as an adjustment to tax expense from continuing operations in the period the amounts are determined. SAB 118 provides that the measurement period is complete when a company's accounting is complete and that in no circumstances should the measurement period extend beyond one year from the enactment date of the applicable change in tax law. Corporate Tax Rate Reduction The Tax Act reduces the federal corporate tax rate to 21.0% effective January 1, 2018. In accordance with Section 15 of the Code, the Company will utilize this rate for its 2017 deferred tax asset and any future reversals. The Company recorded provisional charges for the re-measurement of the deferred tax assets of $939,000 to its income tax expense related to long-term deferred tax assets for the year ended December 31, 2017. The change had no impact on the Company’s financial statements due to a reduction of the valuation allowance. Deemed Repatriation Transition Tax The Deemed Repatriation Transition Tax (the Transition Tax) is a tax on previously untaxed accumulated earnings and profits (E&P) of certain foreign subsidiaries. To determine the amount of the Transition Tax, the Company must determine, in addition to other factors, the amount of post-1986 E&P of the relevant subsidiaries, as well as the amount of non-U.S. income taxes paid on such earnings. Based on preliminary estimates, the Company recorded a provisional Transition Tax obligation of $0. This is due to Parent’s foreign subsidiaries being in a net E&P deficit at December 31, 2017. Former Code Section 162(m) Prior to the enactment of the Tax Act, Section 162(m) of the Code provided for a $1 million limitation on deductible compensation for certain covered employees of SEC filers that traded on an exchange. The definition of compensation did not include amounts related to certain performance-based compensation items. The Tax Act eliminates the exception for all performance-based compensation, including bonuses, stock options and restricted stock. In addition, the term “covered employees” was expanded to additional employees, including the chief financial officer. The new provisions require an analysis of deferred tax assets related to stock compensation to determine whether those assets are more likely than not to be realized, or whether they need to be written off at December 31, 2017. Based on preliminary estimates, the Company does not believe there is any limitation under this provision. Bonus Depreciation/Immediate Expensing For the period of September 27, 2017 through December 31, 2023, companies are allowed to claim 100% bonus depreciation on certain qualified property placed into service. Since the enactment impacts assets placed into service during a period of time for the year ended December 31, 2017, companies may need to recognize the deduction in the current year provision at the enacted tax rate for 2017 (35%) and the related deferral at the enacted tax rate for 2018 (21%). The Company expects to opt out of any bonus deprecation on post September 27, 2017 assets. Any and all deferred tax asset/liability related to the difference in depreciation has been determined using the newly enacted tax rates. The Company has had an overall net operating loss position since its inception. For the years ended December 31, 2017 and 2016, the components of loss before income taxes were as follows (in thousands): Year Ended December 31, 2017 2016 U.S. $ (2,031 ) $ (5,555 ) Foreign (22,171 ) (10,733 ) Total $ (24,202 ) $ (16,288 ) The components of income tax (benefit) for the years ended December 31, 2017 and 2016 were as follows (in thousands): Year Ended December 31, 2017 2016 Current tax expense: Federal $ (1 ) 50 State $ (12 ) 12 Foreign 225 — Total $ 212 $ 62 Deferred tax benefit: Federal $ — $ — State — — Foreign — — Total $ — $ — Total provision for income taxes $ 212 $ 62 A reconciliation of the U.S. statutory income tax rate to the consolidated effective income tax rate was as follows: Year Ended December 31, 2017 2016 U.S. statutory income tax rate 34 % 34 % Non-deductible interest expense — (6 %) Kreos warrant replacement — (2 %) Stock compensation (2 %) — Permanent differences — (1 %) State taxes, net of federal tax effect — 2 % Change in valuation allowance 125 % (20 %) Write off of disallowed recognized built in loss (143 %) — Change in U.S. tax rate (4 %) — Foreign tax rate differences (11 %) (7 %) Other items 1 % — Effective income tax rate 0.0 % 0.0 % Deferred taxes are recognized for temporary differences between the bases of assets and liabilities for financial statement and income tax purposes. The tax effect of temporary differences that give rise to significant portions of the deferred tax assets are as follows (in thousands): Year Ended December 31, 2017 2016 Deferred tax assets: Tax loss carryforwards $ 21,653 $ 15,420 Capitalized expenses — 36,254 Research and development credits 127 140 Accrued expenses 295 1,088 Stock compensation 825 383 Other 35 43 Total gross deferred tax assets 22,935 53,328 Valuation allowance (22,910 ) (53,257 ) Total deferred tax assets 25 71 Deferred tax liabilities: Intangible assets $ 25 $ 40 Temporary difference on financial instruments — 31 Total deferred tax liabilities 25 71 Net deferred tax assets $ — $ — A valuation allowance is recorded against deferred tax assets if it is more likely than not that some or all of the deferred tax assets will not be realized. Due to the uncertainty surrounding the realization of the favorable tax attributes in future returns, the Company has reserved against its deferred tax assets at December 31, 2017 and 2016. The Company had approximately $22.9 million and $53.3 million in valuation allowances recorded against its deferred tax assets as of December 31, 2017 and 2016, respectively. The Company recorded a benefit of $30.2 million due to the change in valuation allowance for the year ended December 31, 2017 and an expense of $3.2 million for the change in valuation allowance for the year ended December 31, 2016. In connection with the Company’s 2017 sale of legacy Biodel IPR&D, the Company realized a previous unrealized built-in loss related to capitalized research expenses and wrote-off the remaining tax basis of $88.4 million, which, when tax effected is $34.7 million. Total net deferred taxes are classified as follows (in thousands) As of December 31, 2017 2016 Noncurrent deferred tax assets $ — $ — Noncurrent deferred tax liabilities — — As of December 31, 2017, deferred tax assets related to net operating loss (NOL) carryforwards were $21.7 million, which may be used subject to certain limitations to offset future taxable income, if any. The NOL includes approximately $14.6 million for U.S. federal tax purposes and $146.0 million for U.S. state tax purposes. These loss carryforwards expire between 2024 and 2036. Additional NOL of approximately $43.8 million were generated in various non-U.S. jurisdictions and will not expire. Utilization of the NOL and credit carryforwards may be subject to a substantial annual limitation due to ownership change limitations that have occurred previously or that could occur in the future as provided by Section 382 of the Code and similar state and foreign provisions. These ownership changes may limit the amount of NOL and credit carryforwards that can be utilized annually to offset future taxable income and tax, respectively. In general, an ownership change, as defined by Code Section 382, results from transactions increasing the ownership of certain shareholders or public groups in the stock of a corporation by more than 50 percentage points over a three‑year period. During 2016, the Company completed an analysis to assess and concluded that an ownership change within the meaning of Code Section 382 occurred. The analysis has not yet been updated beyond 2016. The Company also has state research and development credit carryforwards of approximately $160,000, which expire commencing in fiscal 2022. A valuation allowance has been established on the NOL carryforward and research and development credits as it is uncertain as to whether future taxable income will be generated. The Company’s policy is for any earnings of non-U.S. subsidiaries to be indefinitely invested outside the United States on the basis of estimates that future domestic cash generation will be sufficient to meet future domestic cash needs and the Company’s specific plans for reinvestment of those subsidiary earnings, if any. Uncertain tax positions The Company accounts for uncertain tax positions under the recognition and measurement criteria of ASC 740-10. For those tax positions for which it is more likely than not that a tax benefit will be sustained, the Company records the largest amount of tax benefit with a greater than 50% likelihood of being realized upon settlement with a taxing authority that has full knowledge of all relevant information. If the Company does not believe that it is not more likely than not that a tax benefit will be sustained, no tax benefit is recognized. As of December 31, 2017 and 2016, no uncertain tax positions have been recorded. Interest and penalties related to the settlement of uncertain tax positions, if any, will be reflected in income tax expense. The Company did not recognize any interest or penalties associated with unrecognized tax benefits in the accompanying consolidated financial statements. The Company does not expect any material changes to the unrecognized benefits within 12 months of the reporting date. Due to existence of the valuation allowance, future changes in the Company’s unrecognized tax benefits will not impact its effective tax rate. The Company files U.S. federal and state tax returns and has determined that its major tax jurisdictions are the United States and Massachusetts, as well as United Kingdom and Sweden. There have been no uncertain tax benefits recognized, or related interest or potential penalties, as of December 31, 2017 or 2016. The Company’s tax returns may be examined for certain tax jurisdictions back to December 31, 2014.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Shareholders' Equity	9. Stockholders’ equity Preferred Stock As of December 31, 2017, the Company has 50,000,000 shares of preferred stock authorized. There are no shares of preferred stock issued or outstanding. Common Stock Prior to the closing date of the Biodel Transaction, Albireo Limited had collectively 308,286 Ordinary shares and Ordinary A shares outstanding (pre-exchange ratio 4,404,817 Ordinary shares and Ordinary A shares). In conjunction with the Biodel Transaction: • immediately prior to completion of the Biodel Transaction, Albireo Limited received an investment of $10.0 million in exchange for 9,708,740 Series C preference shares from certain of its existing shareholders; • the 2015 Convertible Loans were converted into 4,248,780 Series C preference shares and the 2014 Convertible Loans were converted into 1,669,997 Series C preference shares, at a conversion rate of €0.749; • 4,679,365 Series A preference shares, 34,674,635 Series B preference shares and 15,627,517 Series C preference shares were converted into 54,981,517 Ordinary shares; and • 59,386,334 Ordinary shares were exchanged for 4,154,639 shares of the Company’s common stock, based on an exchange ratio of 0.06999. Financing On May 30, 2017, the Company completed an underwritten public offering of 2,530,000 shares of its common stock, which included the full exercise of the underwriter’s option to purchase 330,000 shares to cover overallotments, at a price to the public of $20.50 per share. The Company received net proceeds from this offering of $48.5 million, after deducting underwriting discounts, commissions and offering expenses.

Stock-based Compensation

Stock-based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based Compensation	10. Stock-based Compensation On November 3, 2016, the Albireo Pharma, Inc. 2016 Equity Incentive Plan (the 2016 Equity Plan) was approved by the Company’s stockholders. The 2016 Equity Plan replaced Biodel’s 2010 Stock Incentive Plan, as amended (the 2010 Plan), in connection with completion of the Biodel Transaction. The 2016 Equity Plan authorized the issuance of up to 635,000 shares, plus up to 249,059 shares issued if awards outsanding under the 2010 Plan were cancelled, forfeited or expired on or after the Biodel Transaction. All stock options outstanding under the 2010 Plan remain in full force and effect pursuant to their terms and the terms of the 2010 Plan. On September 13, 2017, the Parent’s Board of Directors adopted the Albireo Pharma, Inc. 2017 Inducement Equity Incentive Plan (the 2017 Inducement Plan) without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Listing Rules. Pursuant to the 2017 Inducement Plan, Parent may grant stock options, stock awards and other stock-based awards for up to a total of 150,000 shares of common stock to new employees of the Company. Prior to completion of the Biodel Transaction, Albireo Limited adopted a share option plan on March 18, 2016, providing for the grant of share options to employees, consultants, officers and directors of Albireo Limited or its subsidiaries (the Pre-Transaction Plan). The Pre-Transaction Plan was amended by Albireo Limited on April 18, 2016. Pursuant to the terms of the Pre-Transaction Plan and prior to completion of the Biodel Transaction, Albireo Limited issued or granted options to purchase 246,666 Ordinary A shares. These options were classified as a liability on the basis that they were granted in a currency other than the functional currency of the employing entity of the recipients and were subject to revaluation until exercised or forfeited. The options were replaced with options to purchase shares of the Company’s common stock in conjunction with the Biodel Transaction. The replacement was accounted for as a modification whereby the fair value of the replacement awards was compared to the fair value of the original award immediately before the terms were modified, measured based on the market price of the common stock of Biodel and other pertinent factors on the date of the modification. The options were then classified as equity awards with the liability reclassified to Additional paid in capital. The Company recognized stock-based compensation expense for employees in the accompanying Consolidated Statements of Operations as follows (in thousands): Years Ended December 31, 2017 2016 General and administrative $ 3,406 $ 1,138 Research and development 294 — Total stock-based compensation $ 3,700 $ 1,138 A summary of the outstanding stock options as of December 31, 2017 is as follows: Stock Options Outstanding Number of Shares Weighted- Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding—December 31, 2016 694,869 $ 26.71 7.35 $ 6,435 Granted 448,650 $ 21.44 — $ — Expirations (57,849 ) $ 170.04 — $ — Exercises (50,309 ) $ 7.64 — $ — Outstanding—December 31, 2017 1,035,361 $ 17.78 8.71 $ 11,896 Exercisable—December 31, 2017 365,933 $ 17.20 8.25 $ 5,965 Vested or expected to vest at—December 31, 2017 1,015,939 $ 17.73 8.25 $ 11,408 Aggregate intrinsic value represents the difference between the fair value of the underlying common stock and the exercise price of outstanding, in-the-money options. Options to purchase 19,422 shares of common stock are performance based and vest upon the date the Company files a drug approval application for A4250 for any orphan indication, if such filing occurs prior to a specified date. This unvested performance-based option is excluded from the vested or expected to vest balance as of December 31, 2017. As of December 31, 2017, the total unrecognized compensation expense related to unvested options was $8.9 million, which the Company expects to recognize over a weighted average vesting period of 2.7 years. In determining the estimated fair value of the stock-based awards, the Company uses the Black-Scholes option pricing model and assumptions discussed below. Each of these inputs is subjective and generally requires significant judgment to determine. The fair value of share option awards was estimated with the following assumptions: As of December 31, 2017 As of December 31, 2016 Price per share of common stock $ 17.05-$26.12 $ 1.00-$29.76 Expected term (in years) 5.2-6.9 4.7-6.0 Risk-free interest rate 1.9-2.3% 1.03%-2.0% Expected volatility 69.5-78.4% 81.0%-83.4% Dividend rate 0% 0% The Company recorded additional stock-based compensation expense of $788,000 in general and administrative expenses in its consolidated statement of operations for the year ended December 31, 2017. The additional expense was attributable to the correction of an understatement of expense recorded for the year ended December 31, 2016 due to the use of incorrect service periods for stock options.

Long-term Debt

Long-term Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Long-term Debt	11. Long-term debt December 31, 2017 December 31, 2016 (in thousands) Long-term debt, including current portion: Loan Facility $ — $ 3,075 2014 Convertible Loans — — 2015 Convertible Loans — — Total debt — 3,075 Less: current portion — (3,075 ) Long-term debt $ — $ — Loan Facility The Company (in particular, Albireo Limited) executed a loan agreement (Loan Facility) with Kreos Capital IV (UK) Limited (Kreos UK) in December 2014, at which time the Company borrowed €6.0 million ($7.3 million). The Loan Facility had a term of 36 months with principal and interest payable monthly, with an annual interest rate of 11.5%. In addition, the Company was required to make an end-of-loan payment equal to 1.25% of the amounts lent by Kreos UK. The amount outstanding as of December 31, 2017 was $0, as the Loan Facility has been paid in full. The amount outstanding as of December 31, 2016 was $3.1 million (€2.9 million). The Company paid $178,000 and $552,000 in interest on the Loan Facility for the years ended December 31, 2017 and 2016, respectively. The debt was paid in full during 2017 and therefore there was no remaining debt discount as of December 31, 2017. Interest expense included $161,000 and $907,000 of discount accretion for the years ended December 31, 2017 and 2016, respectively. In May 2017, Kreos Capital exercised the Replacement Kreos Warrants in full on a “cashless” basis. The number of shares of the Company’s common stock issued in the cashless exercise, 29,831 shares, was determined by a formula specified in the warrant document. 2015 Convertible Loans In connection with the Biodel Transaction, the 2015 Convertible Loans were converted into 297,372 shares of the Company’s common stock based on a conversion price of $19.50. The carrying value of the debt at the time of conversion was $2.1 million and the fair value of the derivative liabilities was $1.8 million. The fair value of the shares received at conversion was $5.8 million. The difference between the fair value of the shares and the carrying value of the debt plus the fair value of the derivative liabilities was $1.9 million, which was recognized as a loss on conversion and recorded in Other income and expense for the year ended December 31, 2016. 2014 Convertible Loans In connection with the Biodel Transaction, the 2014 Convertible Loans were converted into 116,883 shares of the Company’s common stock based on a conversion price of $19.50. The carrying value of the debt at the time of conversion was $1.0 million and the fair value of the derivative liabilities was $545,000. The fair value of the shares received at conversion was $2.3 million. The difference between the fair value of the shares and the carrying value of the debt plus the fair value of the derivative liabilities was $732,000, which was recognized as a loss on conversion and recorded in Other income and expense for the year ended December 31, 2016.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	12. Subsequent Events Underwritten Public Offering In January 2018, the Company completed an underwritten public offering of 2,265,500 shares of its common stock at a price to the public of $33.00 per share. The Company’s net proceeds from the offering, after underwriting discounts, commissions and offering expenses, were approximately $69.9 million. Royalty Monetization In December 2017, the Company entered into the RIAA with HCR. Pursuant to the RIAA, HCR agreed, subject to customary closing conditions, to pay to the Company (specifically, Elobix AB) $45 million if elobixibat was approved in Japan by the MHLW and an additional $15 million if a specified sales milestone is achieved for elobixibat in Japan. The MHLW approved a new drug application for elobixibat for the treatment of chronic constipation in January 2018. The Company’s net proceeds from the initial payment received in February 2018, net of certain transaction expenses, were $44.8 million. Milestone Payment In January 2018, the MHLW approved a new drug application filed by EA Pharma for elobixibat for the treatment of chronic constipation, triggering a milestone payment to the Company of €9.0 million ($11.2 million based on the Euro to USD exchange rate at January 31, 2018). At-the-Market Sales In October 2017, the Company entered into an at-the-market offering program Sales Agreement with Cowen and Company, LLC (Cowen) 24.2 million

Summary of Significant Accoun20

Summary of Significant Accounting Policies and Basis of Presentation (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Organization and Share Exchange	Organization and Share Exchange Albireo Pharma, Inc. (Parent), together with its direct and indirect subsidiaries (the Company), is a clinical-stage biopharmaceutical company focused on the development and commercialization of novel bile acid modulators to treat orphan pediatric liver diseases and other liver and gastrointestinal diseases and disorders. The Company’s clinical pipeline includes a Phase 3 product candidate, a Phase 2 product candidate, and elobixibat, which is approved in Japan for the treatment of chronic constipation. A4250, the Company’s Phase 3 lead product candidate, is in development initially for the treatment of patients with progressive familial intrahepatic cholestasis (PFIC), a rare, life-threatening genetic disorder affecting young children. Prior to November 3, 2016, Parent’s name was Biodel Inc. (Biodel). On that date, Biodel effected a 1-for-30 reverse stock split of its common stock (Reverse Stock Split) and completed a share exchange transaction with Albireo Limited, a limited company domiciled in London, United Kingdom, in accordance with the terms of an Amended and Restated Share Exchange Agreement (the Share Exchange Agreement), dated as of July 13, 2016, by and among Biodel, Albireo Limited and the shareholders and noteholders of Albireo Limited. Pursuant to the Share Exchange Agreement, each holder of shares or notes convertible into shares of Albireo Limited received newly issued shares of Biodel common stock and Albireo Limited became a wholly owned subsidiary of Biodel (the Biodel Transaction). Following completion of the Biodel Transaction, the business of Albireo Limited became the business of Parent and Parent changed its name to Albireo Pharma, Inc. For accounting purposes, the Biodel Transaction was treated as a “reverse acquisition” and Albireo Limited was considered the accounting acquirer. Accordingly, these Consolidated Financial Statements reflect the historical results of Albireo Limited and its direct and indirect subsidiaries prior to completion of the Biodel Transaction and do not include the historical results of Biodel prior to completion of the Biodel Transaction. See Note 6. Except as provided in Note 9, all 2017 and 2016 share and per share information has been adjusted to reflect the exchange of shares in the Biodel Transaction based on an exchange ratio of 0.06999 and, where applicable, the Reverse Stock Split.
Basis of Presentation	Basis of presentation These Consolidated Financial Statements have been prepared in conformity with generally accepted accounting principles in the United States (U.S. GAAP). Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification (ASC) and Accounting Standards Update (ASU) of the Financial Accounting Standards Board (FASB). Any reference in these Consolidated Financial Statements to common stock or options or warrants to purchase shares of common stock of the Company means the common stock or options or warrants to purchase shares of common stock of Parent. Any reference in these Consolidated Financial Statements to common stock means, for periods prior to November 3, 2016, Ordinary shares of Albireo Limited.
Principles of Consolidation	Principles of consolidation The accompanying Consolidated Financial Statements include the accounts of Parent and its direct or indirect wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. In the opinion of management, all adjustments (including normal recurring accruals) considered necessary for fair presentation have been included in the Consolidated Financial Statements.
Foreign Currency Translation	Foreign currency translation Functional and presentation currency Items included in the financial statements of each entity comprising the Company are measured using the currency of the primary economic environment in which the entity operates (the functional currency). The functional currency for Parent, Albireo Security Corp. and Albireo, Inc. is the U.S. Dollar (USD), the functional currency for Albireo Limited, Elobix AB and Biodel UK Limited is the Euro, and the functional currency for Albireo AB is the Swedish Krona (SEK). The Company consolidates its financial statements in USD. Transactions and balances Foreign currency transactions in each entity comprising the Company are translated into the functional currency of the entity using the exchange rates prevailing at the dates of the transactions. Foreign exchange gains and losses resulting from the settlement of such transactions and from the translation at year-end exchange rates of monetary assets and liabilities denominated in foreign currencies are recognized within Other income (expense), net in the Consolidated Statements of Operations. The results and financial position of the Company and its subsidiaries that have a functional currency different from the presentation currency are translated into the presentation currency as follows: a. assets and liabilities presented are translated at the closing exchange rate as of December 31, 2017 and 2016; b. income and expenses for the statements of operations and comprehensive loss are translated at average exchange rates that are relevant for the respective periods for which the income and expenses occurred; c. significant transactions use the exchange rate on the date of the transaction; and d. all resulting exchange differences arising from such translation are recognized directly in other comprehensive (loss) income and the cumulative impact is presented in accumulated other comprehensive income as a separate component of equity.
Use of Estimates	Use of estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts of assets, liabilities, revenues and expenses reported in the financial statements and accompanying notes. Management must apply significant judgment in this process. On an ongoing basis, the Company evaluates its estimates and assumptions, including but not limited to accruals, valuation allowances associated with deferred tax assets and, historically, warrant liability, which is estimated at fair value. Actual results could materially differ from these estimates.
Segment Information	Segment information The Company’s entire business is managed by a single management team, which reports to the chief executive officer. The chief executive officer is the chief operating decision maker. The Company has determined it has one operating segment as its chief operating decision maker allocates resources and assesses the performance of the business at this level. Accordingly, the Company has one reporting segment, which is the research and development of novel treatments for liver and gastrointestinal diseases and disorders.
Cash and Cash Equivalents	Cash and cash equivalents The Company considers all short-term highly liquid investments with an original maturity at the date of purchase of three months or less to be cash equivalents.
Concentration of Risk	Concentration of risk Credit risk Financial instruments that potentially subject the Company to significant concentration of credit risk consist primarily of cash and cash equivalents. For banks and financial institutions, only independent financial institutions with a high credit rating are utilized. The Company’s current license agreement is with an established and reputable pharmaceutical company and, historically, the Company has not had any material collection risk related to its accounts receivable. Concentration of revenue and accounts receivable The Company generally does not require collateral or other security in support of accounts receivable. Allowances are provided for individual accounts receivable when the Company becomes aware of a customer’s inability to meet its financial obligations, such as in the case of bankruptcy, deterioration in the customer’s operating results or change in financial position. If circumstances related to a customer change, estimates of the recoverability of receivables would be further adjusted. The Company also considers broad factors in evaluating the sufficiency of its allowances for doubtful accounts, including the length of time receivables are past due, significant one-time events, creditworthiness of customers and historical experience. There is no allowance for doubtful accounts as of December 31, 2017 or 2016.
Equipment, Net	Equipment, net Equipment is stated at historical cost less depreciation and consists of computers, furniture and fixtures, and other equipment. Depreciation is computed using a straight-line method over the estimated useful lives. Computers and other equipment purchased for less than $2,000 or the equivalent thereof are expensed immediately. Gains and losses on disposals of equipment are determined by comparing the proceeds with the carrying amount and are recognized within Other income (expense), net in the Consolidated Statements of Operations.
Impairment of long-lived Assets	Impairment of long-lived assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. In such instances, the recoverability of assets to be held and used is measured first by a comparison of the carrying amount of an asset group to future undiscounted net cash flows expected to be generated by the assets. If such assets are considered to be impaired, an impairment loss would be recognized if the carrying amount of the asset exceeds the fair value of the asset. There were no impairments recorded for the years ended December 31, 2017 and 2016.
Research and Development Expenses	Research and development expenses Research and development costs are expensed as incurred and include primarily salaries, benefits and other staff-related costs; clinical trial and related clinical manufacturing costs; contract services and other outside costs. The Company’s preclinical studies and clinical trials are performed by third-party contract research organizations (CROs). Some of these expenses are billed monthly for services performed, while others are billed based upon milestones achieved. For preclinical studies, the significant factors used in estimating accruals include the percentage of work completed to date and contract milestones achieved. For clinical trial expenses, the significant factors used in estimating accruals include the number of patients enrolled and percentage of work completed to date or contract milestones achieved. The Company’s estimates are highly dependent upon the timeliness and accuracy of the data provided by the respective CROs regarding the status of the contracted activity, with adjustments made when deemed necessary.
Revenue Recognition	Revenue recognition Revenue is generated from the receipt of upfront or license fees, milestone payments and payments for pharmaceutical ingredient or related procurement services that are made pursuant to out-licensing or related supply agreements. Where an out-licensing arrangement of the Company involves the provision of multiple elements that may contain different remuneration arrangements such as upfront payments, milestone payments or product sales, the arrangement is assessed to determine whether separate delivery of the individual elements of such arrangement comprises more than one unit of accounting. The delivered elements are separated if (a) they have value to the licensee on a stand-alone basis, (b) there is objective and reliable evidence of the fair value of the undelivered element(s) and (c) if the arrangement includes a general right of return relative to the delivered element(s), delivery or performance of the undelivered element(s) is considered probable and is substantially in the control of the Company. Allocation of revenue to the different elements that require separate accounting is based on the separate selling prices determined for each component, and total consideration is then allocated pro rata across the components of the arrangement. If separate selling prices are not available, the Company will use its best estimate of such selling prices, consistent with the overall pricing strategy and relevant market factors. The Company has determined that each element of its out-licensing agreements is a separate and distinct unit of accounting, and, as such, the fair value of each element has been subscribed and recognized as follows: • Nonrefundable upfront payments received from the Company’s out-licensing agreements relating to technical expertise and intellectual property are recognized in income if all rights relating to the intellectual property and all obligations resulting from them have been relinquished under the contract terms and the Company has no continuing material obligation to perform under the agreement. However, if rights to the intellectual property continue to exist or obligations resulting from them have yet to be fulfilled, the payments received would be deferred until all rights and obligations have been fulfilled. • Nonrefundable payments that are linked to the achievement of significant and substantive development or regulatory milestones in the research and development process are recognized as revenue upon the achievement of the specified milestone. • Revenue and costs associated with procurement services associated with pharmaceutical ingredients are recognized net in revenue when title and risk of loss of the pharmaceutical ingredients have passed to the licensee as the Company is not the primary obligor, and revenue and costs associated with related procurement services are recognized net in revenue when the Company is contractually bound. As of December 31, 2017, the Company had a license agreement with EA Pharma Co., Ltd. (EA Pharma, formerly Ajinomoto Pharmaceuticals Co., Ltd.), entered into in 2012, to develop a select product candidate (elobixibat) for registration and subsequent commercialization in select markets. The Company satisfied its material performance obligations under the agreement in 2012, upon the delivery of technical expertise and intellectual property rights to EA Pharma. Payments resulting from pharmaceutical ingredient or related procurement services are recognized as revenue as the activities are performed and are presented on a net basis. Revenue is recorded on a net basis because the Company acts as an agent, as it does not have discretion to change suppliers and does not perform any part of the services or manufacture of the subject pharmaceutical ingredients. The costs associated with these activities are netted against the related revenue in the Consolidated Statements of Operations. For certain contingent payments under research and development arrangements, the Company recognizes revenue using the milestone method. Under the milestone method, a payment that is contingent upon the achievement of a substantive milestone is recognized in its entirety in the period in which the milestone is achieved. A milestone is an event: (i) that can be achieved based in whole or in part on either the Company’s performance or on the occurrence of a specific outcome resulting from the Company’s performance, (ii) for which there is substantive uncertainty at the date the arrangement is entered into that the event will be achieved and (iii) that would result in additional payments being due to the Company. The determination that a milestone is substantive requires estimation and judgment and is made at the inception of the arrangement. Milestones are considered substantive when the consideration earned from the achievement of the milestone is: (i) commensurate with either the Company’s performance to achieve the milestone or the enhancement of value of the item delivered as a result of a specific outcome resulting from the Company’s performance to achieve the milestone, (ii) related solely to past performance and (iii) reasonable relative to all deliverables and payment terms in the arrangement. In making the determination as to whether a milestone is substantive or not, management of the Company considers all facts and circumstances relevant to the arrangement, including factors such as the scientific, regulatory, commercial and other risks that must be overcome to achieve the milestone, the level of effort and investment required to achieve the milestone and whether any portion of the milestone consideration is related to future performance or deliverables. The Company has evaluated each milestone specified under its license agreement with EA Pharma and determined the milestone to be substantive. For the year ended December 31, 2017, the Company did not recognize any milestone-based revenue from EA Pharma. For the year ended December 31, 2016, the Company recognized in full into revenue nonrefundable payments of (a) $8.0 million received in April 2016 in connection with a renegotiated payment stream with EA Pharma linked to know-how and intellectual property delivered by the Company upon inception of the license agreement in 2012 and (b) $3.6 million triggered by the decision of EA Pharma to proceed with the preparation of a new drug application for elobixibat in Japan. The renegotiated payment stream was implemented via an amendment to the license agreement that did not change the contingent nature of the remaining deliverables or the parties’ respective obligations under the agreement. Under the terms of the license agreement with EA Pharma, the Company was eligible as of December 31, 2017 to receive up to approximately (a) €13.3 million ($15.9 million based on the Euro to USD exchange rate at December 31, 2017) if specified regulatory events are achieved for elobixibat in Japan and (b) ¥3.5 billion ($31.1 million based on the Japanese Yen to USD exchange rate at December 31, 2017) if specified sales milestones are achieved for elobixibat following regulatory approval in any country in EA Pharma’s licensed territory. Subsequently, in January 2018, the Japanese In December 2017, the Company entered into a royalty interest acquisition agreement, or RIAA, with HealthCare Royalty Partners III, L.P. ( If EA Pharma does not successfully commercialize elobixibat in Japan, the Company may not receive any future payments under its RIAA with HCR or its license agreement with EA Pharma.
Stock-based Compensation	Stock-based compensation The Company accounts for stock-based compensation awards in accordance with FASB ASC Topic 718, Compensation—Stock Compensation The fair value of the Company’s stock options has been determined using the Black-Scholes option pricing model, which requires the input of subjective assumptions, including (i) the expected stock price volatility, (ii) the expected term of the award, (iii) the risk-free interest rate and (iv) expected dividends. For the years ended December 31, 2017 and December 31, 2016, due to the lack of historical and implied volatility data of the Company’s common stock and equivalents, the expected volatility has been estimated based on the historical volatilities of peer companies in the Company’s industry that are publicly traded. The Company selected companies that it considers to have comparable characteristics to the Company, including enterprise value, risk profiles and position within the industry and with historical share price information sufficient to meet the expected term of the stock options. The historical volatility data has been computed using the daily closing prices for the selected companies. Due to the lack of sufficient historical data, the Company used the “simplified” method, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the award, to determine the expected term of stock options. For periods prior to completion of the Biodel Transaction, the risk-free interest rate for periods within the expected term of the option were based on the United Kingdom Government Bond rate with a maturity date commensurate with the expected term of the associated award. For the periods after completion of the Biodel Transaction, the risk-free interest rate for periods within the expected term of the option is based on the United States Government Bond rate with a maturity date commensurate with the expected term of the associated award. In addition, it is assumed that the Company will not pay dividends in the near future. The Company’s stock-based awards are subject to either service-based or service and performance-based vesting conditions. Prior to the Biodel Transaction, the Company issued certain stock options with exercise prices denominated in a foreign currency (Euro) that were required to be accounted for as liabilities. The Company accounted for liability-classified stock-based awards based on the then-current fair values at each financial reporting date. Changes in the amounts attributed to these awards between the reporting dates were included in the Consolidated Statement of Operations. On November 3, 2016, these stock options were replaced with stock options denominated in USD. The replacement was accounted for as a modification, and the post-modification awards are no longer liability-classified awards. The Company records compensation expense for service-based awards over the vesting period of the award on a straight-line basis. For awards with service and performance based conditions, compensation related to the performance-based vesting conditions is recognized when achievement of the performance condition is considered probable and the compensation expense related to the service condition is recorded using the accelerated method. Modifications to stock-based awards are treated as an exchange of the original award for a new award with total compensation equal to the grant-date fair value of the original award plus any incremental value of the modification. The incremental value is based on the excess of the fair value of the modified award over the fair value of the original award immediately before the modification.
Temporary Equity	Temporary equity The Series A and B preference shares of Albireo Limited prior to completion of the Biodel Transaction are classified outside of Stockholders’ Equity (Deficit) on the basis that the shares were redeemable upon a liquidation event that could be forced by the holders of preference shares through their voting rights on the Albireo Limited Board of Directors. Any undeclared dividends are not recognized until the time it becomes probable that the preference shares will be redeemable. No dividends were recognized for either of the years ended December 31, 2017 or 2016. All preference shares of Albireo Limited were converted into Ordinary shares that were exchanged for shares of common stock of the Company as part of the Biodel Transaction.
Employee Benefits	Employee benefits Pension obligations The Company has defined contribution plans for its Sweden-based employees whereby the Company pays contributions to employee benefit or insurance plans on a mandatory, contractual or voluntary basis. The Company has no legal or constructive obligations to pay further contributions if the fund does not hold sufficient assets to pay all employees the benefits relating to employee service in the current and prior periods. The Company has no further payment obligations once the contributions have been paid. The contributions are recognized as employee benefit expense when they are due. Prepaid contributions are recognized as an asset to the extent that a cash refund or a reduction in the future payments is available. The Company paid $317,000 and $331,000 to the plans for the years ended December 31, 2017 and 2016, respectively. 401(k) The Company has a 401(k) retirement plan in which all U.S.-based employees are eligible to participate. The Company contributed $70,200 and $33,000 to the plan for the years ended December 31, 2017 and 2016, respectively. The Company matches employee contributions to the plan, on a per employee basis, up to 4% of each employee’s wages for the years ended December 31, 2017 and 2016.
Loss Contingencies	Loss contingencies Loss contingencies are recorded as liabilities when it is probable that a liability has occurred and the amount of loss is reasonably estimable. Disclosure is required when there is a reasonable possibility that an ultimate loss will be material. Contingent liabilities are often resolved over long periods of time. Estimating probable losses requires analysis that often depends on judgments about potential actions by third parties, such as regulators.
Income Taxes	Income taxes The Company accounts for income taxes in accordance with ASC 740, Income Taxes Income tax expense consists of taxes currently payable and changes in deferred tax assets and liabilities calculated according to local tax rules. Deferred tax assets and liabilities are based on temporary differences that arise between carrying values used for financial reporting purposes and amounts used for taxation purposes of assets and liabilities and the future tax benefits of tax loss carry forwards. A deferred tax asset is recognized only to the extent that it is more likely than not that future taxable profits will be available against which the asset can be utilized. Significant judgment is required in determining any valuation allowance recorded against deferred tax assets. In assessing the need for a valuation allowance, the Company considers all available evidence for each jurisdiction including past operating results, estimates of future taxable income and the feasibility of ongoing tax planning strategies. In the event that the Company changes its determination as to the amount of deferred tax assets that can be realized, the Company will adjust its valuation allowance with a corresponding impact to income tax expense in the period in which such determination is made. The amount of deferred tax provided is calculated using tax rates in effect at the balance sheet date. The impact of tax law changes is recognized in periods when the change is enacted. A two-step approach is applied pursuant to ASC 740 in the recognition and measurement of uncertain tax positions taken or expected to be taken in a tax return. The first step is to determine if the weight of available evidence indicates that it is more likely than not that the tax position will be sustained in an audit, including resolution of any related appeals or litigation processes. The second step is to measure the tax benefit as the largest amount that is more than 50% likely to be realized upon ultimate settlement. The Company’s policy is to recognize interest and penalty expenses associated with uncertain tax positions as a component of income tax expense in the Consolidated Statements of Operations. As of the years ended December 31, 2017 and 2016, the Company had no accrued interest or penalties related to uncertain tax positions and no amounts have been recognized in the Consolidated Statements of Operations.
Net loss per share	Net loss per share Basic net loss per share is calculated by dividing the net loss attributable to holders of common stock by the weighted average number of shares of common stock outstanding. Diluted net loss per share is calculated by dividing the net loss attributable to holders of common stock by the weighted-average number of shares of common stock outstanding. If the Company were in a net income position, diluted net income per share would be calculated by dividing the net income attributable to holders of common stock by the weighted-average number of shares of common stock plus dilutive common stock equivalents outstanding, including any dilutive effect from such shares. For the years ended December 31, 2017 and 2016, common stock equivalents included convertible preference shares, stock options and warrants. The Company’s Convertible Loan Notes (see Note 11) were not included in common stock equivalents, as they were not readily convertible at the option of the respective holders.
Goodwill and Long-Lived Assets	Goodwill and long-lived assets Goodwill is the excess of the purchase price in a business combination over the fair value of identifiable net assets acquired. Goodwill and certain other intangible assets having indefinite lives are not amortized to earnings, but instead are subject to periodic testing for impairment. Goodwill and indefinite-lived intangible assets are assessed at least annually, but also whenever events or changes in circumstances indicate the carrying values may not be recoverable. Factors that could trigger an impairment review, include: (a) significant underperformance relative to historical or projected future operating results; (b) significant changes in the manner of or use of the acquired assets or the strategy for the Company’s overall business; (c) significant negative industry or economic trends; (d) significant decline in the Company’s stock price for a sustained period; and (e) a decline in the Company’s market capitalization below net book value. An entity may assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit, including goodwill, is less than its carrying amount. In evaluating whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, an entity shall assess relevant events and circumstances, both positive and mitigating. An entity shall consider the extent to which each of the adverse events and circumstances identified could affect the comparison of a reporting unit’s fair value with its carrying amount and place more weight on the events and circumstances that most affect a reporting unit’s fair value or the carrying amount of its net assets. If, after assessing the totality of events or circumstances, including those described in the preceding paragraph, an entity determines that it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then the quantitative goodwill impairment test is unnecessary. There are inherent assumptions and estimates used in developing future cash flows requiring management judgment in applying these assumptions, including projecting revenues, interest rates and the cost of capital. Many of the factors used in assessing fair value are outside the Company’s control and it is reasonably likely that assumptions and estimates will change in future periods. These changes can result in future impairments. In the event the Company’s planning assumptions are modified and result in an impairment, the associated expense would be included in the Consolidated Statements of Operations, which could materially impact the Company’s results of operations. The Company conducts an impairment assessment on October 1 each year taking a qualitative evaluation approach to determine if there are any adverse market factors or changes in circumstances indicating that the carrying value of goodwill may not be recoverable. Assessment for possible impairment of long-lived assets is based on the Company’s ability to recover the carrying value of the long-lived asset from the expected future pre-tax cash flows. The expected future pre-tax cash flows are estimated based on historical experience, knowledge and market data. Estimates of future cash flows require the Company to make assumptions and to apply judgment, including forecasting future sales and expenses and estimating the useful lives of assets. If the expected future cash flows related to a long-lived asset are less than the asset’s carrying value, an impairment charge is recognized for the difference between the estimated fair value and the carrying value.
Business Combination Adjustment	Business combination adjustment At the time of the Biodel Transaction in November 2016, the Company preliminarily estimated the fair value of Biodel’s in-process research and development (IPR&D) to be $150,000. Subsequently, the Company continued to evaluate the IPR&D acquired, including the underlying patents, based on information available to the Company as of November 2016. Upon a final evaluation of the IPR&D in 2017, the Company increased the acquisition date value of the IPR&D by $850,000 to $1.0 million and recorded a corresponding reduction to goodwill. In October 2017, the Company entered into an asset purchase agreement pursuant to which it sold IPR&D for $4.5 million, which resulted in a gain recorded in other operating income.
Recently Adopted Accounting Pronouncements	Recently adopted accounting pronouncements In March 2016, the FASB issued ASU No. 2016-09, “ Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting In January 2016, the FASB issued ASU No. 2017-04, “ Intangibles—Goodwill and other (Topic 350): Simplifying the test for goodwill impairments
Accounting Pronouncements Issued but not Yet Adopted	Accounting pronouncements issued but not yet adopted In May 2014, the FASB issued ASU No. 2014-09, “ Revenue from Contracts with Customers: (Topic 606) Revenue Recognition Property, Plant, and Equipment Intangibles-Goodwill and Other In February 2016, the FASB issued ASU 2016-02, “ Leases (Topic 842) In September 2016, the FASB issued ASU 2016-15, “ Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force)

Fair Value of Financial Instrum

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial Instruments Recorded at Fair Value on Recurring Basis	Total Carrying Value on the Consolidated Balance Sheet Fair Value Measurements Fair Value Level December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 (in thousands) Financial Instruments Recorded at Fair Value on a Recurring Basis Current liabilities: Warrants 3 $ — $ 844 $ — $ 844
Financial Instruments with Level 3 Measurement	Derivative Liabilities Warrants December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 (in thousands) Financial Instruments with a Level 3 measurement Balance, beginning $ — $ 2,047 $ 844 $ 1,163 (Income) loss recognized in earnings — 261 (227 ) (294 ) Purchases, sales, issues and settlements — (2,343 ) (617 ) — Foreign currency (gains) losses — 35 — (25 ) Transfers in (out) — — — — Balance, ending $ — $ — $ — $ 844
Binomial Method
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Summary of Assumptions used to Calculate Fair Value of Warrants	The key assumptions used in the binomial method as of December 31, 2016 included the following: December 31, 2016 Stock price $ 17.73 Exercise price $ 11.78 Term (in years) 1.00 Risk-free interest rate 0.85 % Volatility 83.4 %

Equipment, Net (Tables)

Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Summary of Equipment, Net	Equipment, net consisted of the following (in thousands): December 31, 2017 December 31, 2016 Cost: Equipment cost as of January 1, $ 143 $ 142 Additions 190 3 Exchange differences 1 (2 ) Equipment cost as of period end 334 143 Less: Accumulated depreciation as of January 1 (122 ) (108 ) Depreciation for the period (35 ) (12 ) Exchange differences 1 (2 ) Accumulated depreciation as of period end (156 ) (122 ) Total equipment, net $ 178 21

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2017
Payables And Accruals [Abstract]
Summary of Accrued Expenses	Accrued expenses consisted of the following (in thousands): December 31, 2017 December 31, 2016 Accrued bonuses $ 1,717 $ 849 Accrued vacation pay 464 318 Accrued social security pay 217 1,461 Accrued professional fees 470 730 Accrued development costs 1,747 522 Accrued severance 152 2,864 Accrued other 1,338 804 Total accrued expenses $ 6,105 $ 7,548

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Minimum Commitments under Facility Operating Leases	As of December 31, 2017, future minimum commitments under facility operating leases were $1.2 million. Year ended December 31, (in thousands) 2018 331 2019 260 2020 266 2021 271 2022 91 Total Minimum Commitments $ 1,219

Business Combination (Tables)

Business Combination (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Summary of Biodel Transaction Costs Expensed	The expensed transaction costs include: (in thousands) Legal fees 1,187 Accounting fees 653 Advisory fees 2,031 Termination and severance 1,749 Total Transaction Costs $ 5,620
Schedule of Purchase Price	The purchase price is as follows: (in thousands) Fair value of Biodel shares outstanding $ 41,696 Fair value of Biodel stock options 242 Purchase price $ 41,938
Final Allocation of Purchase Consideration to Assets Acquired and Liabilities Assumed	The following presents the final allocation of the purchase consideration to the assets acquired and liabilities assumed as of the acquisition date: (in thousands) Cash and cash equivalents $ 25,483 Other current assets 701 Intangible assets 1,000 Goodwill 17,260 Accounts payable and accrued liabilities (2,215 ) Other current liabilities (286 ) Warrant liabilities (5 ) Total net assets acquired $ 41,938
Summary of Goodwill Activity	The following table summarizes the Company’s goodwill activity: (in thousands) Goodwill at January 1, 2016 $ — Goodwill resulting from share exchange 18,110 Goodwill at December 31, 2016 $ 18,110 Purchasing accounting adjustment (850 ) Goodwill at December 31, 2017 $ 17,260

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Summary of Computation of Basic EPS and Diluted EPS	The following table sets forth the computation of Basic EPS and Diluted EPS (in thousands, except for share and per share data): Year Ended December 31, 2017 2016 Basic and Diluted EPS: Numerator Net loss $ (24,414 ) $ (16,350 ) Net loss attributable to holders of common stock $ (24,414 ) $ (16,350 ) Denominator Weighted average number of shares 7,819,302 1,239,694 Number of shares used for basic and diluted EPS computation 7,819,302 1,239,694 Basic and Diluted EPS $ (3.12 ) $ (13.19 )
Summary of Weighted-Average Outstanding Shares Excluded from Computation of Diluted EPS	The following weighted-average outstanding common stock equivalents were excluded from the computation of Diluted EPS for the periods presented because including them would have been anti-dilutive: Year Ended December 31, 2017 2016 Convertible preference shares (on an as-converted basis) — 2,317,898 Warrants to purchase convertible preference shares (on an as-converted basis) — 6,946 Kreos Warrants to purchase common stock — 67,271 Options to purchase to common stock 889,934 390,155

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Components of Loss Before Income Taxes	For the years ended December 31, 2017 and 2016, the components of loss before income taxes were as follows (in thousands): Year Ended December 31, 2017 2016 U.S. $ (2,031 ) $ (5,555 ) Foreign (22,171 ) (10,733 ) Total $ (24,202 ) $ (16,288 )
Schedule of Components of Income Tax (Benefit)	The components of income tax (benefit) for the years ended December 31, 2017 and 2016 were as follows (in thousands): Year Ended December 31, 2017 2016 Current tax expense: Federal $ (1 ) 50 State $ (12 ) 12 Foreign 225 — Total $ 212 $ 62 Deferred tax benefit: Federal $ — $ — State — — Foreign — — Total $ — $ — Total provision for income taxes $ 212 $ 62
Schedule of Reconciliations of Statutory Income Tax Rate to Consolidated Effective Income Tax Rate	A reconciliation of the U.S. statutory income tax rate to the consolidated effective income tax rate was as follows: Year Ended December 31, 2017 2016 U.S. statutory income tax rate 34 % 34 % Non-deductible interest expense — (6 %) Kreos warrant replacement — (2 %) Stock compensation (2 %) — Permanent differences — (1 %) State taxes, net of federal tax effect — 2 % Change in valuation allowance 125 % (20 %) Write off of disallowed recognized built in loss (143 %) — Change in U.S. tax rate (4 %) — Foreign tax rate differences (11 %) (7 %) Other items 1 % — Effective income tax rate 0.0 % 0.0 %
Schedule of Tax Effect of Temporary Differences To Significant Portions of Deferred Tax Assets	Deferred taxes are recognized for temporary differences between the bases of assets and liabilities for financial statement and income tax purposes. The tax effect of temporary differences that give rise to significant portions of the deferred tax assets are as follows (in thousands): Year Ended December 31, 2017 2016 Deferred tax assets: Tax loss carryforwards $ 21,653 $ 15,420 Capitalized expenses — 36,254 Research and development credits 127 140 Accrued expenses 295 1,088 Stock compensation 825 383 Other 35 43 Total gross deferred tax assets 22,935 53,328 Valuation allowance (22,910 ) (53,257 ) Total deferred tax assets 25 71 Deferred tax liabilities: Intangible assets $ 25 $ 40 Temporary difference on financial instruments — 31 Total deferred tax liabilities 25 71 Net deferred tax assets $ — $ —
Schedule of Components of Total Net Deferred Taxes	Total net deferred taxes are classified as follows (in thousands) As of December 31, 2017 2016 Noncurrent deferred tax assets $ — $ — Noncurrent deferred tax liabilities — —

Stock-based Compensation (Table

Stock-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Recognized Stock-based Compensation Expense	The Company recognized stock-based compensation expense for employees in the accompanying Consolidated Statements of Operations as follows (in thousands): Years Ended December 31, 2017 2016 General and administrative $ 3,406 $ 1,138 Research and development 294 — Total stock-based compensation $ 3,700 $ 1,138
Summary of Outstanding Stock Options	A summary of the outstanding stock options as of December 31, 2017 is as follows: Stock Options Outstanding Number of Shares Weighted- Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding—December 31, 2016 694,869 $ 26.71 7.35 $ 6,435 Granted 448,650 $ 21.44 — $ — Expirations (57,849 ) $ 170.04 — $ — Exercises (50,309 ) $ 7.64 — $ — Outstanding—December 31, 2017 1,035,361 $ 17.78 8.71 $ 11,896 Exercisable—December 31, 2017 365,933 $ 17.20 8.25 $ 5,965 Vested or expected to vest at—December 31, 2017 1,015,939 $ 17.73 8.25 $ 11,408
Summary of Estimated Fair Value of Share Option Awards	The fair value of share option awards was estimated with the following assumptions: As of December 31, 2017 As of December 31, 2016 Price per share of common stock $ 17.05-$26.12 $ 1.00-$29.76 Expected term (in years) 5.2-6.9 4.7-6.0 Risk-free interest rate 1.9-2.3% 1.03%-2.0% Expected volatility 69.5-78.4% 81.0%-83.4% Dividend rate 0% 0%

Long-term Debt (Tables)

Long-term Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Long-term Debt	December 31, 2017 December 31, 2016 (in thousands) Long-term debt, including current portion: Loan Facility $ — $ 3,075 2014 Convertible Loans — — 2015 Convertible Loans — — Total debt — 3,075 Less: current portion — (3,075 ) Long-term debt $ — $ —

Summary of Significant Accoun30

Summary of Significant Accounting Policies and Basis of Presentation - Additional Information (Details) € in Millions, ¥ in Billions	Nov. 03, 2016USD ($)	Jul. 13, 2016	Feb. 28, 2018USD ($)	Jan. 31, 2018USD ($)	Jan. 31, 2018EUR (€)	Dec. 31, 2017USD ($)	Oct. 31, 2017USD ($)	Dec. 31, 2017USD ($)Segment	Dec. 31, 2017EUR (€)Segment	Dec. 31, 2017JPY (¥)Segment	Dec. 31, 2016USD ($)	Jan. 01, 2018USD ($)	Dec. 31, 2015USD ($)
Summary Of Significant Accounting Policies [Line Items]
Reverse stock split	0.033	0.06999
Operating segments | Segment								1	1	1
Reportable segments | Segment								1	1	1
Allowance for doubtful accounts						$ 0		$ 0			$ 0
Computer and other equipment purchased						334,000		334,000			143,000		$ 142,000
Impairment of long-lived assets								0			0
Milestone-based revenue								0
Revenue recognized nonrefundable amount received											8,000,000
Revenue recognition to be received upon approval of new drug application											3,600,000
Revenue recognition milestone received								15,900,000	€ 13.3
Dividends								0			0
Pension expense paid								317,000			331,000
Accrued interest or penalties related to uncertain tax positions						0		0			0
Biodel Inc.
Summary Of Significant Accounting Policies [Line Items]
Reverse stock split	0.06999
Estimated research and development in process	$ 150,000					1,000,000		1,000,000
Research and development in process increased after final evaluation								850,000
Sale of research and develpment in process							$ 4,500,000
U.S.-Based Employees Retirement Plan
Summary Of Significant Accounting Policies [Line Items]
Defined contribution plan, employer contribution amount								$ 70,200,000			$ 33,000,000
Maximum employer matching contribution to 401(k) plan, percent								400.00%	400.00%	400.00%	400.00%
Royalty Interest Acquisition Agreement
Summary Of Significant Accounting Policies [Line Items]
Revenue recognition milestone received						45,000,000
Subsequent Event
Summary Of Significant Accounting Policies [Line Items]
Revenue recognition milestone received				$ 11,200,000	€ 9
Subsequent Event | ASU No. 2014-09
Summary Of Significant Accounting Policies [Line Items]
Cumulative adjustment on date of adoption												$ 0
Subsequent Event | Royalty Interest Acquisition Agreement
Summary Of Significant Accounting Policies [Line Items]
Revenue recognition milestone received			$ 45,000,000	$ 11,200,000	€ 9
Sales Milestones
Summary Of Significant Accounting Policies [Line Items]
Revenue recognition milestone received								$ 31,100,000		¥ 3.5
Sales Milestones | Royalty Interest Acquisition Agreement
Summary Of Significant Accounting Policies [Line Items]
Revenue recognition milestone received						$ 15,000,000
Sales Milestones | Subsequent Event | Royalty Interest Acquisition Agreement
Summary Of Significant Accounting Policies [Line Items]
Revenue recognition milestone received			$ 15,000,000
Maximum | Royalty Interest Acquisition Agreement
Summary Of Significant Accounting Policies [Line Items]
Maximum percentage of royalty interest to be payable under license agreement						175.00%
Computer and Other Equipment | Maximum
Summary Of Significant Accounting Policies [Line Items]
Computer and other equipment purchased						$ 2,000,000		$ 2,000,000

Fair Value of Financial Instr31

Fair Value of Financial Instruments - Additional Information (Details)	Oct. 01, 2015Note$ / Note	Dec. 17, 2014Note	Dec. 17, 2014$ / Note	Dec. 17, 2014€ / Note	Sep. 30, 2016EUR (€)	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)shares	May 31, 2017shares	May 10, 2017USD ($)shares	Dec. 31, 2016EUR (€)shares
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of Loan Facility							$ 3,400,000
Fair value of liabilities transferred from level 1 to level 2						$ 0
Fair value of liabilities transferred from level 2 to level 1						0
Fair value of liabilities transferred into level 3						0
Fair value of liabilities transferred from level 3						$ 0
Fair value of warrants							$ 844,000
Common stock, shares issued | shares						8,902,784	6,292,644			6,292,644
Binomial Method
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of warrants decreased						$ 227,000	$ 294,000
Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Common stock, shares issued | shares								29,831	29,831
Replacement Kreos Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants to purchase common stock | shares						67,271
Exercise price warrants | $ / shares						$ 11.78
Fair value of warrants							$ 844,000		$ 617,000	€ 762,000
Kreos Capital | Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants issued with a right to acquire shares | €					€ 720,000
2014 Convertible Loans
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Number of convertible loan notes outstanding | Note		1,251,000
Convertible notes price per unit			1.12	1
2015 Convertible Loans
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Number of convertible loan notes outstanding | Note	5,000,000
Convertible notes price per unit | $ / Note	1

Fair Value of Financial Instr32

Fair Value of Financial Instruments - Financial Instruments Recorded at Fair Value on Recurring Basis (Details) $ in Thousands	Dec. 31, 2016USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants liability	$ 844
Recurring [Member] | Total Carrying Value on the Consolidated Balance Sheet | Fair Value Level 3 | Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants liability	844
Recurring [Member] | Fair Value Measurements | Fair Value Level 3 | Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants liability	$ 844

Fair Value of Financial Instr33

Fair Value of Financial Instruments - Financial Instruments with Level 3 Measurement (Details) - Fair Value Level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Warrants
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning	$ 844	$ 1,163
(Income) loss recognized in earnings	(227)	(294)
Purchases, sales, issues and settlements	$ (617)
Foreign currency (gains) losses		(25)
Balance, ending		844
Derivative Liabilities
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning		2,047
(Income) loss recognized in earnings		261
Purchases, sales, issues and settlements		(2,343)
Foreign currency (gains) losses		$ 35

Fair Value of Financial Instr34

Fair Value of Financial Instruments - Summary of Assumptions used to Calculate Fair Value of Warrants (Details) - Binomial Method - Warrants	12 Months Ended
	Dec. 31, 2016$ / shares
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Stock price	$ 17.73
Exercise price	$ 11.78
Term (in years)	1 year
Risk-free interest rate	0.85%
Volatility	83.40%

Equipment, Net - Summary of Equ

Equipment, Net - Summary of Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Cost:
Equipment cost, beginning balance	$ 143	$ 142
Additions	190	3
Exchange differences	1	(2)
Equipment cost, ending balance	334	143
Less:
Accumulated depreciation, beginning balance	(122)	(108)
Depreciation for the period	(35)	(12)
Exchange differences	1	(2)
Accumulated depreciation, ending balance	(156)	(122)
Total equipment, net	$ 178	$ 21

Equipment, Net - Additional Inf

Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Property Plant And Equipment [Abstract]
Depreciation expense	$ 34,000	$ 14,000

Accrued Expenses - Summary of A

Accrued Expenses - Summary of Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Payables And Accruals [Abstract]
Accrued bonuses	$ 1,717	$ 849
Accrued vacation pay	464	318
Accrued social security pay	217	1,461
Accrued professional fees	470	730
Accrued development costs	1,747	522
Accrued severance	152	2,864
Accrued other	1,338	804
Total accrued expenses	$ 6,105	$ 7,548

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017USD ($)ft²Time	Dec. 31, 2017SEK (kr)ft²Time	Dec. 31, 2016USD ($)
Loss Contingencies [Line Items]
Future minimum commitments under facility operating leases	$ 1,219,000
IBAT- Inhibitor
Loss Contingencies [Line Items]
One-time, launch fee payment	487,000	kr 4,000,000
CROs
Loss Contingencies [Line Items]
Agreement on leases future minimum payments upon completion of contracted work	$ 18,800,000
Office Space
Loss Contingencies [Line Items]
Lease expiration date	Nov. 30, 2019	Nov. 30, 2019
Operating Lease Commitments
Loss Contingencies [Line Items]
Future minimum commitments under facility operating leases	$ 1,200,000
Rent expense	$ 394,000		$ 122,000
Operating Lease Commitments | Office Space | Albireo
Loss Contingencies [Line Items]
Building lease agreement term	36 months	36 months
Number of square feet | ft²	5,100	5,100
Operating leases periodic payment	$ 37,818	kr 322,917
Operating leases renewal term	The current term of the lease expires in November 2019, but renews automatically thereafter for consecutive three-year terms unless notice of nonrenewal is given by either party at least nine months prior to the end of the current term and subject to Albireo AB’s right to terminate the lease at any time upon six months’ notice.	The current term of the lease expires in November 2019, but renews automatically thereafter for consecutive three-year terms unless notice of nonrenewal is given by either party at least nine months prior to the end of the current term and subject to Albireo AB’s right to terminate the lease at any time upon six months’ notice.
Automatic lease renewal term	3 years	3 years
Period of notice for non-renewal of lease	9 months	9 months
Period of notice for termination	6 months	6 months
Operating Lease Commitments | SHIGO 10 PO Owner LLC
Loss Contingencies [Line Items]
Term of lease	The initial term of the lease is 62 months beginning on March 1, 2017. Parent has the option to extend the lease one time for an additional 5-year period.	The initial term of the lease is 62 months beginning on March 1, 2017. Parent has the option to extend the lease one time for an additional 5-year period.
Number of option available to extend the lease period | Time	1	1
Additional period of lease	5 years	5 years
Rent abatement period	2 months	2 months
Monthly rent payments	$ 20,997
Annual increase rent payment percentage	2.00%
Operating Lease Commitments | SHIGO 10 PO Owner LLC | 10 Post Office Square, Boston, Massachusetts
Loss Contingencies [Line Items]
Rentable square feet | ft²	5,116

Commitments and Contingencies39

Commitments and Contingencies - Schedule of Future Minimum Commitments under Facility Operating Leases (Details) $ in Thousands	Dec. 31, 2017USD ($)
Commitments And Contingencies Disclosure [Abstract]
2,018	$ 331
2,019	260
2,020	266
2,021	271
2,022	91
Total Minimum Commitments	$ 1,219

Business Combination - Addition

Business Combination - Additional Information (Details) $ / shares in Units, $ in Thousands	Nov. 03, 2016director$ / sharesshares	Jul. 13, 2016	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)shares
Business Acquisition [Line Items]
Aggregate shares of common stock issued			8,902,784	6,292,644
Stock exchange ratio	0.033	0.06999
General and administrative expense | $			$ 15,246	$ 15,786
Employee Stock Option
Business Acquisition [Line Items]
Volatility rate, minimum			69.50%	81.00%
Volatility rate, maximum			78.40%	83.40%
Risk free interest rate' minimum			1.90%	1.03%
Risk free interest rate, maximum			2.30%	2.00%
Employee Stock Option | Minimum
Business Acquisition [Line Items]
Expected term			5 years 2 months 12 days	4 years 8 months 12 days
Employee Stock Option | Maximum
Business Acquisition [Line Items]
Expected term			6 years 10 months 24 days	6 years
Albireo Limited
Business Acquisition [Line Items]
Number of former directors | director	5
Biodel Inc.
Business Acquisition [Line Items]
Date of merger agreement	Nov. 3, 2016
Number of former directors | director	2
Aggregate shares of common stock issued	4,154,369
Combined organization common stock outstanding, percentage	66.70%
Stock exchange ratio	0.06999
Options to purchase common stock shares outstanding	351,550
General and administrative expense | $				$ 1,200
Purchase price per share | $ / shares	$ 19.50
Biodel Inc. | Employee Stock Option
Business Acquisition [Line Items]
Volatility rate, minimum	75.70%
Volatility rate, maximum	79.00%
Risk free interest rate' minimum	0.64%
Risk free interest rate, maximum	0.72%
Biodel Inc. | Employee Stock Option | Minimum
Business Acquisition [Line Items]
Expected term	1 year
Biodel Inc. | Employee Stock Option | Maximum
Business Acquisition [Line Items]
Expected term	1 year 6 months

Business Combination - Summary

Business Combination - Summary of Biodel Transaction Costs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Business Combinations [Abstract]
Legal fees	$ 1,187
Accounting fees	653
Advisory fees	2,031
Termination and severance	1,749
Total Transaction Costs	$ 5,620

Business Combination - Schedule

Business Combination - Schedule of Purchase Price (Details) - Biodel Inc. $ in Thousands	Nov. 03, 2016USD ($)
Business Acquisition [Line Items]
Fair value of Biodel shares	$ 41,696
Purchase price	41,938
Employee Stock Option
Business Acquisition [Line Items]
Fair value of Biodel shares	$ 242

Business Combination - Final Al

Business Combination - Final Allocation of Purchase Consideration to Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Nov. 03, 2016
Business Acquisition [Line Items]
Goodwill	$ 17,260	$ 18,110
Biodel Inc.
Business Acquisition [Line Items]
Cash and cash equivalents			$ 25,483
Other current assets			701
Intangible assets			1,000
Goodwill			17,260
Accounts payable and accrued liabilities			(2,215)
Other current liabilities			(286)
Warrant liabilities			(5)
Total net assets acquired			$ 41,938

Business Combination - Summar44

Business Combination - Summary of Goodwill Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Business Combinations [Abstract]
Beginning Balance	$ 18,110
Goodwill resulting from share exchange		$ 18,110
Purchasing accounting adjustment	(850)
Ending Balance	$ 17,260	$ 18,110

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Computation of Basic EPS and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Numerator
Net loss	$ (24,414)	$ (16,350)
Denominator
Weighted average number of shares used for basic and diluted EPS computation	7,819,302	1,239,694
Basic and Diluted EPS	$ (3.12)	$ (13.19)
Common Stock
Numerator
Net loss	$ (24,414)	$ (16,350)
Denominator
Weighted average number of shares used for basic and diluted EPS computation	7,819,302	1,239,694

Net Loss Per Share - Summary 46

Net Loss Per Share - Summary of Weighted-Average Outstanding Shares Excluded from Computation of Diluted EPS (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Convertible Preference Shares (on an as-converted basis)
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share		2,317,898
Warrants to Purchase Convertible Preference Shares (on an as-converted basis)
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share		6,946
Kreos Warrants to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share		67,271
Options to Purchase to Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share	889,934	390,155

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended			75 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2023
Income Tax [Line Items]
Federal corporate tax rate		34.00%	34.00%
Tax Cuts and Jobs Act of 2017, decrease in deferred tax asset		$ 939,000
Net impact of decrease in deferred tax asset and valuation allowance		0
Tax Cuts and Jobs Act of 2017, deferred tax assets, provisional income tax expense		939,000
Tax Cuts and Jobs Act of 2017, provisional Transitional Tax obligation		0
Limitation on deductible compensation		1,000,000
Deferred tax assets, valuation allowances		22,910,000	$ 53,257,000
Tax cuts and job acts of 2017, income tax expense (benefit) due to change in valuation allowance		(30,200,000)	3,200,000
Tax loss carryforwards		$ 21,653,000	15,420,000
Period for change in ownership percentage		3 years
Unrecognized tax benefits		$ 0	0
Interest or potential penalties accrued for uncertain tax positions		$ 0	$ 0
Minimum [Member]
Income Tax [Line Items]
Percentage of change in ownership for operating loss carryforward		50.00%
Earliest Tax Year
Income Tax [Line Items]
Operating loss carryforwards expiration year		2,024
Latest Tax Year
Income Tax [Line Items]
Operating loss carryforwards expiration year		2,036
U.S. Federal Tax
Income Tax [Line Items]
Net operating loss		$ 14,600,000
U.S. State Tax
Income Tax [Line Items]
Net operating loss		146,000,000
U.S. State Tax | Research and Development Tax Credit Carryforwards
Income Tax [Line Items]
Tax credit carryforwards		$ 160,000
U.S. State Tax | Earliest Tax Year | Research and Development Tax Credit Carryforwards
Income Tax [Line Items]
Tax credit carryforward expiration year		2,022
Non-U.S. Jurisdictions
Income Tax [Line Items]
Net operating loss		$ 43,800,000
IPR&D | Biodel Inc.
Income Tax [Line Items]
Write off the remaining capitalized research expense		88,400,000
Write off the remaining capitalized research expense, tax effected		$ 34,700,000
Scenario Plan
Income Tax [Line Items]
Federal corporate tax rate	21.00%
Scenario Forecast
Income Tax [Line Items]
Percentage of bonus depreciation on certain qualified property placed into service				100.00%

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Loss Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
U.S.	$ (2,031)	$ (5,555)
Foreign	(22,171)	(10,733)
Net loss before income taxes	$ (24,202)	$ (16,288)

Income Taxes - Schedule of Co49

Income Taxes - Schedule of Components of Income Tax (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Current tax expense:
Federal	$ (1)	$ 50
State	(12)	12
Foreign	225
Total	212	62
Deferred tax benefit:
Total provision for income taxes	$ 212	$ 62

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliations of Statutory Income Tax Rate to Consolidated Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
U.S. statutory income tax rate	34.00%	34.00%
Non-deductible interest expense		(6.00%)
Kreos warrant replacement		(2.00%)
Stock compensation	(2.00%)
Permanent differences		(1.00%)
State taxes, net of federal tax effect		2.00%
Change in valuation allowance	125.00%	(20.00%)
Write off of disallowed recognized built in loss	(143.00%)
Change in U.S. tax rate	(4.00%)
Foreign tax rate differences	(11.00%)	(7.00%)
Other items	1.00%
Effective income tax rate	0.00%	0.00%

Income Taxes - Schedule of Tax

Income Taxes - Schedule of Tax Effect of Temporary Differences To Significant Portions of Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Tax loss carryforwards	$ 21,653	$ 15,420
Capitalized expenses		36,254
Research and development credits	127	140
Accrued expenses	295	1,088
Stock compensation	825	383
Other	35	43
Total gross deferred tax assets	22,935	53,328
Valuation allowance	(22,910)	(53,257)
Total deferred tax assets	25	71
Deferred tax liabilities:
Intangible assets	25	40
Temporary difference on financial instruments		31
Total deferred tax liabilities	$ 25	$ 71

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Details) $ / shares in Units, $ in Thousands	May 30, 2017USD ($)$ / sharesshares	Dec. 31, 2017USD ($)shares	Dec. 31, 2017€ / sharesshares	Dec. 31, 2016USD ($)shares
Class Of Stock [Line Items]
Preferred stock, shares authorized		50,000,000	50,000,000
Preferred stock, shares issued		0	0
Preferred stock, shares outstanding		0	0
Common stock, shares outstanding		8,902,784	8,902,784	6,292,644
Investment received | $				$ 40
Convertible preferred stock conversion rate | € / shares			€ 0.749
Exchange ratio		0.06999
May 2017 Underwritten Public Offering
Class Of Stock [Line Items]
Number of shares issued in transaction	2,530,000
Sale of stock, price per share | $ / shares	$ 20.50
Proceeds from sale of stock | $	$ 48,500
Option to purchase shares	330,000
Common Stock
Class Of Stock [Line Items]
Number of ordinary shares exchanged for common stock		4,154,639
Ordinary Shares And Ordinary A Shares
Class Of Stock [Line Items]
Common stock, shares outstanding		308,286	308,286
Series C Preference Shares
Class Of Stock [Line Items]
Convertible loans converted		15,627,517
Series C Preference Shares | 2015 Convertible Loans
Class Of Stock [Line Items]
Convertible loans converted		4,248,780
Series C Preference Shares | 2014 Convertible Loans
Class Of Stock [Line Items]
Convertible loans converted		1,669,997
Series C Preference Shares | Albireo Limited
Class Of Stock [Line Items]
Investment received | $		$ 10,000
Exchange of preference shares		9,708,740
Series A Preferred Stock
Class Of Stock [Line Items]
Convertible loans converted		4,679,365
Series B Preferred Stock
Class Of Stock [Line Items]
Convertible loans converted		34,674,635
Ordinary Shares
Class Of Stock [Line Items]
Convertible loans converted		54,981,517
Number of ordinary shares exchanged for common stock		59,386,334

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Details) - USD ($)	Nov. 03, 2016	Apr. 18, 2016	Dec. 31, 2017	Dec. 31, 2016	Sep. 13, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options issued or granted			448,650
Total unrecognized compensation expense related to unvested options			$ 8,900,000
Total stock-based compensation			3,700,000	$ 1,138,000
General and Administrative Expenses
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation			3,406,000	$ 1,138,000
General and Administrative Expenses | Miscalculation
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation			$ 788,000
Albireo Limited | Ordinary A Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options issued or granted		246,666
Performance Based Options | Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options, non vested			19,422
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average vesting period for unvested options			2 years 8 months 12 days
2016 Equity Incentive Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized under plan	635,000
Additional number of shares to be issued if awards outstanding under the 2010 Plan were cancelled, forfeited or expired on or after the Transaction	249,059
2017 Inducement Equity Incentive Plan | Maximum | Stock Options, Stock Awards or Other Stock-Based Awards to New Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock available for grant					150,000

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Recognized Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 3,700	$ 1,138
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	3,406	$ 1,138
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 294

Stock-based Compensation - Su55

Stock-based Compensation - Summary of Outstanding Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Summary of the stock option activity
Number of Shares Outstanding, Beginning Balance	694,869
Number of Shares, Granted	448,650
Number of Shares, Expirations	(57,849)
Number of Shares, Exercises	(50,309)
Number of Shares Outstanding, Ending Balance	1,035,361	694,869
Number of Shares, Exercisable	365,933
Number of Shares, Vested or expected to vest	1,015,939
Weighted- Average Exercise Price Per Share Outstanding, Beginning Balance	$ 26.71
Weighted- Average Exercise Price Per Share, Granted	21.44
Weighted- Average Exercise Price Per Share, Expirations	170.04
Weighted Average Exercise Price Per Share, Exercises	7.64
Weighted- Average Exercise Price Per Share Outstanding, Ending Balance	17.78	$ 26.71
Weighted- Average Exercise Price Per Share Exercisable	17.20
Weighted- Average Exercise Price Per Share Vested or expected to vest	$ 17.73
Outstanding, Weighted Average Remaining Contractual Term (Years)	8 years 8 months 15 days	7 years 4 months 6 days
Exercisable , Weighted- Average Remaining Contractual Term (Years)	8 years 3 months
Vested or expected to vest, Weighted- Average Remaining Contractual Term (Years)	8 years 3 months
Outstanding options, Aggregate Intrinsic Value	$ 6,435
Outstanding options, Aggregate Intrinsic Value	11,896	$ 6,435
Exercisable options, Aggregate Intrinsic Value	5,965
Vested or expected to vest options, Aggregate Intrinsic Value	$ 11,408

Stock-based Compensation - Su56

Stock-based Compensation - Summary of Estimated Fair Value of Share Option Awards (Details) - Employee Stock Option - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Stock Based Compensation [Line Items]
Risk-free interest rate, minimum	1.90%	1.03%
Risk-free interest rate, maximum	2.30%	2.00%
Expected volatility, minimum	69.50%	81.00%
Expected volatility, maximum	78.40%	83.40%
Dividend rate	0.00%	0.00%
Minimum
Stock Based Compensation [Line Items]
Price per share of common stock	$ 17.05	$ 1
Expected term (in years)	5 years 2 months 12 days	4 years 8 months 12 days
Maximum
Stock Based Compensation [Line Items]
Price per share of common stock	$ 26.12	$ 29.76
Expected term (in years)	6 years 10 months 24 days	6 years

Long-term Debt - Schedule of Lo

Long-term Debt - Schedule of Long-term Debt (Details) $ in Thousands, € in Millions	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2016EUR (€)
Debt Instrument [Line Items]
Total debt		$ 3,075
Less: current portion		(3,075)
Long-term debt	$ 0	0
Loan Facility
Debt Instrument [Line Items]
Total debt		$ 3,075	€ 2.9

Long-term Debt - Loan Facility

Long-term Debt - Loan Facility - Additional Information (Details) € in Millions	1 Months Ended		12 Months Ended
	Dec. 31, 2014USD ($)	Dec. 31, 2014EUR (€)	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)shares	May 31, 2017shares	May 10, 2017shares	Dec. 31, 2016EUR (€)shares
Debt Instrument [Line Items]
Long-term debt				$ 3,075,000
Interest paid on loan facility			$ 178,000	$ 450,000
Common stock, shares issued | shares			8,902,784	6,292,644			6,292,644
Warrants
Debt Instrument [Line Items]
Common stock, shares issued | shares					29,831	29,831
Loan Facility
Debt Instrument [Line Items]
Long-term debt, borrowed amount	$ 7,300,000	€ 6
Long-term debt				$ 3,075,000			€ 2.9
Loan facility, term			36 months
Loan facility, description			The Loan Facility had a term of 36 months with principal and interest payable monthly, with an annual interest rate of 11.5%. In addition, the Company was required to make an end-of-loan payment equal to 1.25% of the amounts lent by Kreos UK.
Long-term debt			$ 0
Loan facility annual interest rate				11.50%			11.50%
Interest paid on loan facility			178,000	$ 552,000
Debt discount			0
Interest expense include discount accretion			$ 161,000	$ 907,000

Long-term Debt - 2015 Convertib

Long-term Debt - 2015 Convertible Loans - Additional Information (Details) - 2015 Convertible Loans - Biodel Transaction - USD ($) $ / shares in Units, $ in Millions	Dec. 31, 2015	Dec. 31, 2016	Nov. 03, 2016
Debt Instrument [Line Items]
Carrying value of the debt at the time of conversion			$ 2.1
Derivative liabilities			1.8
Fair value of convertible loan			$ 5.8
Common Stock
Debt Instrument [Line Items]
Convertible loans converted into shares	297,372
Convertible loans conversion price			$ 19.50
Other income and expense
Debt Instrument [Line Items]
Loss on conversion of convertible loans		$ (1.9)

Long-term Debt - 2014 Convertib

Long-term Debt - 2014 Convertible Loans - Additional Information (Details) - 2014 Convertible Loans - Biodel Transaction - USD ($)	Dec. 31, 2015	Dec. 31, 2016	Nov. 03, 2016
Debt Instrument [Line Items]
Carrying value of the debt at the time of conversion			$ 1,000,000
Derivative liabilities			545,000
Fair value of convertible loan			$ 2,300,000
Common Stock
Debt Instrument [Line Items]
Convertible loans converted into shares	116,883
Convertible loans conversion price			$ 19.50
Other income and expense
Debt Instrument [Line Items]
Loss on conversion of convertible loans		$ (732,000)

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) $ / shares in Units, € in Millions, ¥ in Billions	1 Months Ended					12 Months Ended
	Feb. 28, 2018USD ($)shares	Jan. 31, 2018USD ($)$ / sharesshares	Jan. 31, 2018EUR (€)shares	Dec. 31, 2017USD ($)	Oct. 31, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2017EUR (€)	Dec. 31, 2017JPY (¥)
Subsequent Event [Line Items]
Revenue recognition milestone received						$ 15,900,000	€ 13.3
Sales Milestones
Subsequent Event [Line Items]
Revenue recognition milestone received						$ 31,100,000		¥ 3.5
Royalty Interest Acquisition Agreement
Subsequent Event [Line Items]
Revenue recognition milestone received				$ 45,000,000
Royalty Interest Acquisition Agreement | Sales Milestones
Subsequent Event [Line Items]
Revenue recognition milestone received				$ 15,000,000
At-the-market Offering Program | Cowen | Maximum
Subsequent Event [Line Items]
Common stock to be offered and sold at sole discretion					$ 50,000,000
Subsequent Event
Subsequent Event [Line Items]
Revenue recognition milestone received		$ 11,200,000	€ 9
Subsequent Event | Royalty Interest Acquisition Agreement
Subsequent Event [Line Items]
Revenue recognition milestone received	$ 45,000,000	$ 11,200,000	€ 9
Net proceeds from agreement, after offering expenses	44,800
Subsequent Event | Royalty Interest Acquisition Agreement | Sales Milestones
Subsequent Event [Line Items]
Revenue recognition milestone received	$ 15,000,000
Subsequent Event | Underwritten Public Offering
Subsequent Event [Line Items]
Number of shares issued in transaction | shares		2,265,500	2,265,500
Sale of stock, price per share | $ / shares		$ 33
Proceeds from sale of stock		$ 69,900,000
Subsequent Event | At-the-market Offering Program | Cowen
Subsequent Event [Line Items]
Aggregate shares of common stock sold | shares	728,862
Proceeds from issuance of common stock, net of offering expenses	$ 24,200,000