GW Pharmaceuticals (GWPRF) 10-K 27 Feb 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 21, 2020	Jun. 30, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Registrant Name	GW PHARMACEUTICALS PLC
Entity Central Index Key	0001351288
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Document Annual Report	true
Document Transition Report	false
Entity File Number	001-35892
Entity Incorporation, State or Country Code	X0
Entity Tax Identification Number	00-0000000
City Area Code	+44
Local Phone Number	1223 266800
Entity Address, Address Line One	Sovereign House
Entity Address, Address Line Two	Vision Park
Entity Address, Address Line Three	Chivers Way, Histon
Entity Address, City or Town	Cambridge
Entity Address, Postal Zip Code	CB24 9BZ
Entity Address, Country	GB
Entity Common Stock, Shares Outstanding		371,731,604
Entity Public Float			$ 5,165,756,855
Title of 12(b) Security	American Depositary Shares, each representing 12 Ordinary Shares, par value £0.001 per share
Trading Symbol	GWPH
Security Exchange Name	NASDAQ
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of the Registrant’s Proxy Statement to be used in connection with the solicitation of proxies for the Registrant’s 2020 Annual Meeting of Shareholders are incorporated by reference in Part III of this Annual Report on Form 10-K.

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets
Cash and cash equivalents	$ 536,933	$ 591,497
Accounts receivable, net	48,883	4,192
Inventory	85,528	33,030
Prepaid expenses and other current assets	28,292	17,903
Total current assets	699,636	646,622
Property, plant, and equipment, net	127,765	90,832
Operating lease assets	24,916
Goodwill	6,959	6,959
Deferred tax assets	18,123	8,720
Other assets	4,850	2,935
Total assets	882,249	756,068
Liabilities and stockholders’ equity
Accounts payable	9,990	9,796
Accrued liabilities	99,374	52,477
Current tax liabilities	437	2,384
Other current liabilities	7,760	1,559
Total current liabilities	117,561	66,216
Long-term liabilities:
Finance lease liabilities	5,573	5,690
Operating lease liabilities	21,650
Other liabilities	11,431	10,082
Total long-term liabilities	38,654	15,772
Total liabilities	156,215	81,988
Commitments and contingencies (Note 10)
Stockholders’ equity:
Ordinary shares par value £0.001; 371,068,436 and 366,616,688 shares outstanding as of December 31, 2019 and 2018, respectively	570	564
Additional paid-in capital	1,632,046	1,581,144
Accumulated deficit	(837,959)	(828,940)
Accumulated other comprehensive loss	(68,623)	(78,688)
Total stockholders’ equity	726,034	674,080
Total liabilities and stockholders’ equity	$ 882,249	$ 756,068

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - £ / shares	Dec. 31, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Ordinary shares, par value	£ 0.001	£ 0.001
Ordinary shares, outstanding	371,068,436	366,616,688

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Revenues
Total revenues	$ 6,654	$ 311,332	$ 12,737	$ 8,629
Operating expenses
Cost of product sales	1,829	27,199	5,986	4,521
Research and development	29,086	142,678	153,736	112,249
Selling, general and administrative	49,083	259,880	141,818	58,020
Total operating expenses	79,998	429,757	301,540	174,790
Loss from operations	(73,344)	(118,425)	(288,803)	(166,161)
Interest income	2,449	8,464	3,645	2,063
Interest expense	(295)	(1,087)	(1,249)	(951)
Other income	0	104,117	0	0
Foreign exchange loss	(982)	(2,272)	(4,963)	(6,442)
Loss before income taxes	(72,172)	(9,203)	(291,370)	(171,491)
Income tax (benefit) expense	(266)	(184)	3,797	(1,032)
Net loss	$ (71,906)	$ (9,019)	$ (295,167)	$ (170,459)
Net loss per common share, basic and diluted	$ (0.20)	$ (0.02)	$ (0.88)	$ (0.56)
Weighted average common shares outstanding, basic and diluted	366,458	371,580	333,936	305,826
Product Net Sales
Revenues
Total revenues	$ 6,617	$ 310,331	$ 10,469	$ 7,957
Other Revenue
Revenues
Total revenues	$ 37	$ 1,001	$ 2,268	$ 672

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (71,906)	$ (9,019)	$ (295,167)	$ (170,459)
Foreign currency translation adjustments	(3,494)	10,065	(676)	10,008
Comprehensive income (loss)	$ (75,400)	$ 1,046	$ (295,843)	$ (160,451)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities
Net loss	$ (71,906)	$ (9,019)	$ (295,167)	$ (170,459)
Adjustments to reconcile net loss to net cash used in operating activities:
Foreign exchange loss	742	2,709	4,917	9,280
Stock-based compensation	9,683	48,030	31,627	15,479
Depreciation and amortization	2,534	9,240	9,290	7,054
Deferred income taxes	(1,265)	(9,698)	(317)	(3,770)
Gain from sale of priority review voucher		(104,117)
Other		39	241	1,554
Changes in operating assets and liabilities:
Accounts receivable, net	(2,125)	(44,623)	(804)	(277)
Inventory	(14,460)	(51,125)	(13,646)	5
Prepaid expenses and other current assets	(3,635)	(9,831)	14,489	(12,471)
Other assets	(47)	3,888	(564)
Accounts payable	(1,211)	805	2,238	3,171
Current tax liabilities	878	(963)	54	57
Accrued liabilities	5,942	43,110	16,507	1,253
Other liabilities	410	(1,914)	(733)	150
Net cash used in operating activities	(74,460)	(123,469)	(231,868)	(148,974)
Cash flows from investing activities
Proceeds from sale of priority review voucher		104,117
Additions to property, plant and equipment	(18,687)	(40,386)	(31,362)	(19,285)
Additions to capitalized software	(63)	(2,102)	(2,042)	(812)
Proceeds from disposal of property, plant and equipment			517
Net cash provided by (used in) investing activities	(18,750)	61,629	(32,887)	(20,097)
Cash flows from financing activities
Proceeds from issuance of ordinary shares, net of issuance costs	324,638		297,931
Proceeds from exercise of stock options		2,878	621	122
Payments on finance leases	(40)	(389)	(276)	(261)
Payments on landlord financing obligation	(130)	(543)	(522)	(1,074)
Net cash provided by (used in) financing activities	324,468	1,946	297,754	(1,213)
Effect of exchange rate changes on cash	5,326	5,330	(240)	8,993
Net increase (decrease) in cash and cash equivalents	236,584	(54,564)	32,759	(161,291)
Cash and cash equivalents at beginning of period	354,913	591,497	322,154	483,445
Cash and cash equivalents at end of period	591,497	536,933	354,913	322,154
Supplemental disclosure of cash flow information:
Income taxes paid		10,462	3,726	2,928
Interest paid	198	1,087	1,249	1,232
Supplemental disclosure of noncash information:
Property and equipment purchases in accounts payable and accrued liabilities	$ 1,899	$ 923	$ 322	$ 1,793

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning balance at Sep. 30, 2016	$ 525,673	$ 479	$ 901,128	$ (291,408)	$ (84,526)
Beginning balance, Shares at Sep. 30, 2016		302,093
Issuance of common stock from exercise of stock options	122	$ 3	119
Issuance of common stock from exercise of stock options, Shares		2,347
Net loss	(170,459)			(170,459)
Stock-based compensation	15,479		15,479
Other comprehensive income (loss)	10,008				10,008
Ending balance at Sep. 30, 2017	380,823	$ 482	916,726	(461,867)	(74,518)
Ending balance, Shares at Sep. 30, 2017		304,440
Issuance of common stock in public offering,net of issuance costs	297,932	$ 44	297,888
Issuance of common stock in public offering, net of issuance costs, Shares		33,120
Issuance of common stock from exercise of stock options	620	$ 4	616
Issuance of common stock from exercise of stock options, Shares		2,687
Net loss	(295,167)			(295,167)
Stock-based compensation	31,627		31,627
Other comprehensive income (loss)	(676)				(676)
Ending balance at Sep. 30, 2018	415,159	$ 530	1,246,857	(757,034)	(75,194)
Ending balance, Shares at Sep. 30, 2018		340,247
Issuance of common stock in public offering,net of issuance costs	324,638	$ 34	324,604
Issuance of common stock in public offering, net of issuance costs, Shares		26,220
Issuance of common stock from exercise of stock options, Shares		150
Net loss	(71,906)			(71,906)
Stock-based compensation	9,683		9,683
Other comprehensive income (loss)	(3,494)				(3,494)
Ending balance at Dec. 31, 2018	674,080	$ 564	1,581,144	(828,940)	(78,688)
Ending balance, Shares at Dec. 31, 2018		366,617
Issuance of common stock from exercise of stock options	2,878	$ 6	2,872
Issuance of common stock from exercise of stock options, Shares		4,452
Net loss	(9,019)			(9,019)
Stock-based compensation	48,030		48,030
Other comprehensive income (loss)	10,065				10,065
Ending balance at Dec. 31, 2019	$ 726,034	$ 570	$ 1,632,046	$ (837,959)	$ (68,623)
Ending balance, Shares at Dec. 31, 2019		371,069

Business Overview

Business Overview	12 Months Ended
	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Business Overview	Note 1: Business Overview GW Pharmaceuticals plc and its subsidiaries (referred to herein as “we,” “us,” “our,” and the “Company”) is a biopharmaceutical company focused on discovering, developing and commercializing novel therapeutics from our proprietary cannabinoid product platform in a broad range of disease areas. The Company is developing a portfolio of cannabinoid medicines, of which the lead product is Epidiolex, an oral medicine for the treatment of certain refractory childhood epilepsies. The Company is a public limited company, which has had American Depository Shares (ADSs) registered with the U.S. Securities and Exchange Commission (SEC) and has been listed on Nasdaq since May 1, 2013. Until December 5, 2016, the Company was also listed on the Alternative Investment Market, which is a submarket of the London Stock Exchange. The Company is incorporated and domiciled in the United Kingdom. The address of the Company’s registered office and principal place of business is Sovereign House, Vision Park, Histon, Cambridgeshire.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2: Summary of Significant Accounting Policies Basis of Presentation The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Change of Fiscal Year We changed our fiscal year end to December 31 from September 30, effective December 31, 2018. This annual report is for the year ended December 31, 2019. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States (U.S. GAAP) requires management to make estimates and assumptions that affect the reported amounts in the consolidated financial statements and accompanying notes. Actual results could differ from these estimates. Foreign Currency Translation The financial position and results of operations of the Company’s non-U.S. subsidiaries are generally determined using local currency as the functional currency. Assets and liabilities of these subsidiaries are translated at the exchange rate in effect at each year end. Income statement accounts are translated at the average rate of exchange prevailing during the year. Adjustments arising from the use of differing exchange rates from period to period are included in accumulated other comprehensive loss in stockholders’ equity. Foreign currency transaction gains and losses are included in “foreign exchange loss” in the Company’s consolidated statements of operations. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity date of three months or less to be cash equivalents. Fair Value of Financial Instruments The carrying values of the Company’s financial instruments, consisting of cash and cash equivalents, trade receivables, interest and other receivables, and accounts payable and accrued liabilities, approximate fair value due to the relative short-term nature of these instruments. Accounts Receivable Accounts receivable are recorded net of customer allowances for prompt payment discounts, chargebacks, and doubtful accounts. Allowances for prompt payment discounts and chargebacks are based on contractual terms. The Company estimates the allowance for doubtful accounts based on existing contractual payment terms, actual payment patterns of its customers and individual customer circumstances. As of December 31, 2019, the allowance for doubtful accounts was $0.3 million. At December 31, 2018, the Company determined that an allowance for doubtful accounts was not required and no accounts were written off during the period. Inventory Inventory is stated at the lower of cost or estimated net realizable value. The Company uses a combination of standard and actual costing methodologies to determine the cost basis for its inventories which approximates actual cost. Inventory is valued on a first-in, first-out basis. The Company reduces its inventory to net realizable value for potentially excess, dated or obsolete inventory based on an analysis of forecasted demand compared to quantities on hand, as well as product shelf life. Our inventory production process includes the cultivation of botanical raw material. Because of the duration of the cultivation process, a portion of our inventory will not be sold within one year. Consistent with the practice in other industries that cultivate botanical raw materials, all inventory is classified as a current asset. The Company capitalizes inventory costs associated with its products upon regulatory approval when, based on management’s judgment, future commercialization is considered probable and the future economic benefit is expected to be realized; otherwise, such costs are expensed. Prior to FDA approval of Epidiolex, all costs related to the manufacturing of Epidiolex were charged to research and development expense in the period incurred. Property, Plant, and Equipment Property, plant, and equipment are recorded at cost and depreciated over their estimated useful lives using the straight-line method. Leasehold improvements are amortized over the shorter of their estimated useful lives or the term of the lease by use of the straight-line method. The estimated useful lives for buildings and leasehold improvements range from 4 to 20 years. The estimated useful lives of machinery and equipment range from 3 to 20 years. Construction-in-process reflects amounts incurred for property, equipment or improvements that have not been placed in service. Maintenance and repair costs are expensed as incurred. When assets are retired or sold, the assets and accumulated depreciation are removed from the respective accounts and any gain or loss is recognized. Impairment of Long-Lived Assets The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by a comparison of the carrying amount of an asset to estimated future operating cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset. Goodwill Goodwill represents the excess of purchase price over fair value of net assets acquired in a business combination and is not amortized. Goodwill is subject to impairment testing at least annually or when a triggering event occurs that could indicate a potential impairment. We performed the annual assessment for goodwill impairment in December of 2019, noting no impairment Revenue Recognition The Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Accounting Standards Codification (ASC) Topic 606, Revenue from Contracts with Customers (Topic 606), the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. Revenue for the Company’s product sales has not been adjusted for the effects of a financing component as the Company expects, at contract inception, that the period between when the Company’s transfers control of the product and when the Company receives payment will be one year or less. Product shipping and handling costs are included in cost of product sales. Epidiolex Product Net Sales Epidiolex was approved by the FDA in June 2018. Subsequent to the approval by the FDA, the United States Drug Enforcement Agency (DEA) took action to change the classification of Epidiolex from a Schedule I controlled substance to a Schedule V controlled substance, thereby allowing Epidiolex to be prescribed and distributed in the United States. On November 1, 2018, the Company launched sales of Epidiolex to specialty pharmacies (SPs) and specialty distributors (SDs). The Company recognizes revenue from product sales upon receipt of product at the SPs and SDs, the date at which the control is transferred, net of the following allowances which are reflected either as a reduction to the related account receivable or as an accrued liability, depending on how the allowance is settled: Distribution Fees : Distribution fees include distribution service fees paid to the SPs and SDs based on a contractually fixed percentage of the wholesale acquisition cost (WAC), and prompt payment discounts. Distribution fees are recorded as an offset to revenue based on contractual terms at the time revenue from the sale is recognized. Rebates : Allowances for rebates include mandated discounts under the Medicaid Drug Rebate Program and the Medicare Part D prescription drug benefit, and contractual rebates with commercial payers. Rebates are amounts owed after the final dispensing of the product to a benefit plan participant and are based upon contractual agreements or statutory requirements. The allowance for rebates is based on contracted or statutory discount rates and expected utilization by benefit plan participants. The Company’s estimates for expected utilization of rebates is based on utilization data received from the SPs since product launch. Rebates are generally invoiced and paid in arrears so that the accrual balance consists of an estimate of the amount expected to be incurred for the current quarter’s activity, plus an accrual balance for prior quarters’ unpaid rebates. If actual future rebates vary from estimates, the Company may need to adjust prior period accruals, which would affect revenue in the period of adjustment. Chargebacks : Chargebacks are discounts and fees that relate to contracts with government and other entities purchasing from the SDs at a discounted price. The SDs charge back to the Company the difference between the price initially paid by the SDs and the discounted price paid to the SDs by these entities. The Company also incurs group purchasing organization fees for transactions through certain purchasing organizations. The Company estimates sales with these entities and accrues for anticipated chargebacks and organization fees, based on the applicable contractual terms. If actual future chargebacks vary from these estimates, the Company may need to adjust prior period accruals, which would affect revenue in the period of adjustment. Co-Payment Assistance : The Company offers co-payment assistance to commercially insured patients meeting certain eligibility requirements. Co-payment assistance is accrued for based on actual program participation and estimates of program redemption using data provided by third-party administrators. Product Returns : Consistent with industry practice, the Company offers the SPs and SDs limited product return rights for damages, shipment errors, and expiring product , provided that the return is within a specified period around the product expiration date as set forth in the applicable individual distribution agreement. The Company does not allow product returns for product that has been dispensed to a patient. As the Company receives inventory reports from the SPs and SDs and has the ability to control the amount of product that is sold to the SPs and SDs, it is able to make a reasonable estimate of future potential product returns based on this on-hand channel inventory data and sell-through data obtained from the SPs and SDs. In arriving at its estimate, the Company also considers historical product returns, the underlying product demand, and industry data specific to the specialty pharmaceutical distribution industry. On September 23, 2019, the Company announced that the European Commission (EC) approved the marketing authorization for Epidyolex™ (the trade name in Europe for Epidiolex) for use as adjunctive therapy of seizures associated with Lennox‑Gastaut syndrome (LGS) or Dravet syndrome, in conjunction with clobazam, for patients two years of age and older. The Company recognizes revenue from product sales in Europe upon delivery of the product, which is the point at which control of the goods is transferred to the customer. The Company recognizes revenue net of standard discounts and allowances, which are reflected as accrued liabilities. The Company also sells Epidiolex in certain markets outside of the United States under early access programs that enable patients to receive the product prior to regulatory approval. Revenue under early access programs is generally recognized when the product is delivered. The total amount deducted from gross sales for the allowances described above for the year ended December 31, 2019 was $63.3 million Sativex Product Net Sales Sales of Sativex are made outside of the United States for the treatment of spasticity due to multiple sclerosis, or MS, pursuant to license agreements with commercial partners. Under these license agreements, the Company sells fully labeled Sativex vials to its commercial partners for a contractually agreed price, which is generally based on percentages of the commercial partners’ in-market net selling price charged to end customers. Product net sales revenue related to Sativex shipments to commercial license partners is recognized when shipped, at which point the customer obtains control of the product. The Company commercializes Sativex in Australia and New Zealand through a consignment relationship with a local distributor. Product net sales revenues related to Sativex sales in Australia and New Zealand are recognized when the product is sold through to the end customer. Other Revenue The Company’s other revenue primarily consists of research and development fee revenue for services provided under a license agreement with Otsuka Pharmaceutical Co. Ltd (Otsuka) The research and development fee revenue is recognized at the time the underlying services are performed. The Sativex license agreements contain provisions for the Company to earn variable consideration in the form of regulatory milestone payments, sales-based milestone payments, and royalty payments. The Company has no further performance obligations related to the regulatory milestone payments and these amounts are recognized in accordance with Topic 606 when receipt of these payments becomes probable and there is no significant risk of revenue reversal. Revenue related to the sales-based milestone payments and product royalty payments are subject to the sales-based royalty exception under Topic 606 and is recognized when the underlying sales are made. Research and Development Expenses Research and development expenses are charged to operations as incurred. Research and development expenses include, among other things, internal and external costs associated with preclinical development, pre-commercialization manufacturing expenses, and clinical trials. The Company accrues for costs incurred as the services are being provided by monitoring the status of the trial or services provided and the invoices received from its external service providers. In the case of clinical trials, a portion of the estimated cost normally relates to the projected cost to treat a patient in the trials, and this cost is recognized based on the number of patients enrolled in the trial. As actual costs become known, the Company adjusts its accruals accordingly. Research and development expense is presented net of reimbursements from reimbursable tax and expenditure credits from the U.K. government. The majority of the Company’s pipeline research, clinical trials management and the Epidiolex and Sativex chemistry and manufacturing controls development activities, which are generally carried out by a subsidiary in the U.K., are eligible for inclusion under the U.K tax and expenditure rebate schemes. For the year ended December 31, 2019, three months ended December 31, 2018 and years ended September 30, 2018 and 2017, the Company recorded $4.0 million, $0.8 million, $4.3 million, and $26.0 million, respectively, of U.K. tax and expenditure rebates as a component of research and development expense. Concentration Risk Financial instruments, which potentially subject the Company to concentrations of credit risk, principally consist of cash, cash equivalents, investment securities, and accounts receivable. The Company’s cash and cash equivalents balances are primarily in depository accounts at major financial institutions in accordance with the Company’s investment policy. The Company’s investment policy defines allowable investments and establishes guidelines relating to credit quality, diversification, and maturities of its investments to preserve principal and maintain liquidity. Further, the Company specifies credit quality standards for its customers that are designed to limit the Company’s credit exposure to any single party. For the year ended December 31, 2019, the Company’s five largest customers represented approximately 85% of the Company’s product net sales and 86% of the Company’s accounts receivable balance as of December 31, 2019. For the three months ended December 31, 2018, the Company’s five largest customers represented approximately 71% of the Company’s product net sales and 75% of the Company’s accounts receivable balance as of December 31, 2018. For the years ended September 30, 2018 and 2017, product net sales consisted entirely of Sativex sales outside of the United States pursuant to license agreements with a small number of commercial partners. Share-based Compensation The Company recognizes share-based compensation expense for grants of stock options under the Company's Long-Term Incentive Plans to employees and non-employee members of the Company's board of directors based on the grant-date fair value of those awards. The grant-date fair value of an award is generally recognized as compensation expense over the award's requisite service period. Expense related to awards with graded vesting is generally recognized over the vesting period using the accelerated attribution method. The Company uses the Black-Scholes model to compute the estimated fair value of stock option awards. Using this model, fair value is calculated based on assumptions with respect to (i) expected volatility of the Company's ADS price, (ii) the periods of time over which employees and members of the board of directors are expected to hold their options prior to exercise (expected lives), (iii) expected dividend yield on the ordinary shares, and (iv) risk-free interest rates. Share-based compensation expense also includes an estimate, which is made at the time of grant, of the number of awards that are expected to be forfeited. This estimate is revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Income Taxes The Company recognizes deferred tax assets and liabilities for temporary differences between the financial reporting basis and the tax basis of the Company's assets and liabilities along with net operating loss and tax credit carryovers. The Company records a valuation allowance against its deferred tax assets to reduce the net carrying value to an amount that it believes is more likely than not to be realized. When the Company establishes or reduces the valuation allowance against its deferred tax assets, its provision for income taxes will increase or decrease, respectively, in the period such determination is made. Valuation allowances against the Company’s deferred tax assets were $114.5 million and $101.6 million at December 31, 2019 and 2018, respectively. Changes in the valuation allowances are generally recognized in the provision for income taxes as a component of the estimated annual effective tax rate. Uncertain tax positions, for which management's assessment is that there is more than a 50% probability of sustaining the position upon challenge by a taxing authority based upon its technical merits, are subjected to certain recognition and measurement criteria. The Company re-evaluates uncertain tax positions and considers various factors, including, but not limited to, changes in tax law, the measurement of tax positions taken or expected to be taken in tax returns, and changes in facts or circumstances related to a tax position. The Company adjusts the level of the liability to reflect any subsequent changes in the relevant facts and circumstances surrounding the uncertain positions. The Company recognizes interest and penalties related to income tax matters in income tax expense. Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share is computed by dividing the net loss by the weighted average number of common shares and common stock equivalents outstanding for the period determined using the treasury stock method. For purposes of this calculation, market-priced stock options are considered to be common stock equivalents but are not included in the calculations of diluted net loss per share for the periods presented as their effect would be anti-dilutive. Nominal strike-price options are considered common stock equivalents and are included in the calculation of basic weighted average shares outstanding once they have become vested. The Company incurred net losses for all periods presented and there were no reconciling items for potentially dilutive securities. More specifically, at December 31, 2019, December 31, 2018, and September 30, 2018, and 2017, options totaling approximately 11.8 million, Segment and Geographic Reporting Management has determined that the Company operates in one business segment which is the discovery, development and commercialization of novel therapeutics from its proprietary cannabinoid product platform in a broad range of disease areas. Revenues recorded in the year ended December 31, 2019, three months ended December 31, 2018, and years ended September 30, 2018, and 2017 were generated in the following geographical areas: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 (in thousands) United Kingdom 2,550 220 1,761 1,758 United States 288,164 4,669 1,560 121 Europe 16,516 1,131 6,882 5,447 Other 4,102 634 2,534 1,303 Total revenues $ 311,332 $ 6,654 $ 12,737 $ 8,629 Long-lived assets which include property, plant, and equipment were located as follows: December 31, 2019 2018 (in thousands) United Kingdom $ 123,207 $ 89,550 United States 4,558 1,282 Total long-lived assets $ 127,765 $ 90,832 Recently Issued Accounting Standards Accounting Standards Update (ASU) 2016-13, Measurement of Credit Losses on Financial Instruments: In June 2016, the FASB issued ASU 2016-13, which amends the impairment model by requiring entities to use a forward-looking approach based on expected losses to estimate credit losses on certain types of financial instruments, including trade receivables and available-for-sale debt securities. This guidance is effective for annual reporting periods beginning after December 15, 2019, including interim periods. The Company is finalizing the credit loss calculations and does not expect the adoption of this standard to have a significant impact on the Company’s consolidated financial statements. ASU 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes: In December 2019, the FASB issued ASU No. 2019-12, Simplifying the Accounting for Income Taxes, as part of its initiative to reduce complexity in accounting standards. The amendments in the ASU are effective for fiscal years beginning after December 15, 2020, including interim periods therein. Early adoption of the standard is permitted, including adoption in interim or annual periods for which financial statements have not yet been issued. We have not early adopted this ASU for 2019. The ASU is currently not expected to have a material impact on our consolidated financial statements. Recently Adopted Accounting Standards ASU 2016-02, Leases: On January 1, 2019, the Company adopted ASU 2016-02 using the modified retrospective method. This new accounting standard requires a lessee to recognize an asset and liability for most leases on its balance sheet. The Company elected the optional transition method that allowed for a cumulative-effect adjustment as of January 1, 2019 and did not restate previously reported results in the comparative periods. The Company also elected to adopt certain practical expedients allowed by the new standard, which among other things, allowed the Company to carry forward its historical lease classification. As a result of adoption of the new standard, the Company recorded operating lease assets and liabilities of approximately $20.5 million and $21.1 million, respectively, as of January 1, 2019. The operating lease liability was determined based on the present value of the remaining minimum rental payments and the operating lease asset was determined based on the value of the lease liability, adjusted for existing deferred rent balances, which were previously included in other current liabilities and other liabilities. Accounting for the Company’s finance leases remains substantially unchanged. As a result of the adoption of the new leasing accounting standard, the Company’s build-to-suit asset has been reclassified to buildings and the build-to-suit financing obligation has been reclassified to finance lease obligation in the consolidated balance sheets. In addition, the adoption of this new accounting standard resulted in increased qualitative and quantitative disclosures regarding the amount, timing, and uncertainty of cash flows arising from leases. For further details, see Note 11, Leases .

Sativex License Agreements

Sativex License Agreements	12 Months Ended
	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Sativex License Agreements	Note 3: Sativex License Agreements The Company has entered into license agreements for Sativex with major pharmaceutical companies that provide the license partners with exclusive rights in a defined geographic territory to commercialize Sativex for all indications. The Company has retained the exclusive right to manufacture and supply Sativex to license partners on commercial supply terms for the duration of the commercial life of the product. In 2007, the Company entered into an exclusive license agreement with Otsuka Pharmaceutical Co., Ltd

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 4: Fair Value Measurements At December 31, 2019 and December 31, 2018, the Company’s cash equivalents consisted of money market funds, which are classified as Level 1 within the fair value hierarchy defined by authoritative guidance. Securities classified as Level 1 are valued using quoted market prices.

Composition of Certain Balance

Composition of Certain Balance Sheet Captions	12 Months Ended
	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Composition of Certain Balance Sheet Captions	Note 5: Composition of Certain Balance Sheet Captions: Inventory consisted of the following: December 31, 2019 2018 (in thousands) Raw materials $ 1,976 $ 676 Work in process 78,547 28,709 Finished goods 5,005 3,645 $ 85,528 $ 33,030 Property, plant and equipment, net, consisted of the following: December 31, 2019 2018 (in thousands) Buildings 4,725 4,573 Machinery and equipment 36,323 32,598 Leasehold improvements 42,744 36,004 Office and IT equipment 3,837 2,481 Construction-in-process 78,485 44,546 166,114 120,202 Accumulated depreciation (38,349 ) (29,370 ) $ 127,765 $ 90,832 Depreciation of property and equipment was $ million, $ million, $ 8.5 million, and $ 7.0 million, for the year ended December 31, 2019, three months ended December 31, 2018 and for the years ended September 30, 2018, and 2017, respectively. The Company did no t retire any property, plant, or equipment in the year ended December 31, 2019 and three months ended December 31, 2018. During the years ended September 30, 2018 and 2017 , the Company retired $ 0.5 million, $ 1.8 million, respectively, of fully depreciated property , plant and equipment. Accrued liabilities consisted of the following: December 31, 2019 2018 (in thousands) Accrued compensation and benefits $ 25,469 $ 18,482 Accrued vendor fees 29,731 11,452 Clinical trial accruals 10,382 10,059 Accrued growing fees 3,818 2,717 Accrued sales rebates and discounts 22,995 628 Other 6,979 9,139 $ 99,374 $ 52,477 Other current liabilities consisted of the following: December 31, 2019 2018 (in thousands) Finance lease liabilities $ 305 $ 400 Operating lease liabilities 5,902 — Landlord financing 595 539 Other 958 620 $ 7,760 $ 1,559 Other liabilities consisted of the following: December 31, 2019 2018 (in thousands) Landlord financing obligation $ 9,152 $ 9,434 Other 2,279 648 $ 11,431 $ 10,082

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Stockholders' Equity	Note 6: Stockholders’ Equity In October 2018, the Company completed a public offering of 2,185,000 ADSs listed on the Nasdaq Global Market, representing 26,220,000 ordinary shares of the Company, at a price of $158.00 per ADS. The net proceeds from this transaction after underwriting discounts and commissions were approximately $324.6 million. In December 2017, the Company completed a public offering of 2,760,000 ADSs listed on the Nasdaq Global market, representing 33,120,000 ordinary shares of the Company, at a price of $115.00 per ADS. The net proceeds from this transaction after underwriting discounts and commissions were approximately $297.9 million.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation	Note 7: Share-Based Compensation Stock Plans In March 2008, the Company adopted the GW Pharmaceuticals plc Long-Term Incentive Plan (the 2008 LTIP Plan). Share based awards granted by the Company from March 2008 to March 2017 were granted under the 2008 LTIP Plan. On March 14, 2017, the Company adopted the GW Pharmaceuticals plc 2017 Long-Term Incentive Plan (the 2017 LTIP Plan). The 2017 LTIP plan authorizes the Company to issue up to an aggregate of 15.0 million ordinary shares, or 1.3 million ADSs, related to share-based awards to employees, non-employee directors and consultants. No grants under the 2017 LTIP Plan may be made after March 13, 2022. As of December 31, 2019, 10.3 million ordinary shares have been or may be issued pursuant to share-based awards that have been granted under the 2017 LTIP Plan. The Company issues new ordinary shares and the commensurate number of ADS when share-based awards are exercised. Provisions of Share-Based Awards The Company issues nominal strike price stock options, which have an exercise price equal to the £0.001 par value per ordinary share of the Company’s ordinary shares, to executive officers, employees and non-employee directors. The Company also issues market-priced options to executive officers and non-employee directors. Nominal strike priced options granted to U.S. residents prior to April 2017 contain short-term expiration provisions so the awards are compliant with provisions of IRS Code 409(a). Nominal strike price options granted to U.S. residents beginning in April 2017 are awarded in the form of RSU-style options that automatically exercise on the vesting date. Substantially all of the share-based awards issued by the Company have service-based vesting conditions. Many awards also have non-market-based performance conditions, which must be achieved within the service-based vesting period for the awards to vest. These performance conditions are generally linked to operational, regulatory or strategic milestones and are designed to incentivize individual employees and advance the Company’s progress towards its strategic objectives. Share-based awards that do not automatically exercise at vest date expire ten years from the date of grant. Share-Based Award Activity The following tables summarize the Company’s stock option activity. The number of options, the weighted average grant date fair value per stock option, and the weighted average exercise price are all on a per ordinary shares basis. The Company’s ADSs that are listed on the Nasdaq Global Market each represent twelve ordinary shares. The following table summarizes the Company’s nominal strike price stock option activity: Year Ended Three Months Ended Years Ended December 31, December 31, September 30, 2019 2018 2018 2017 Nominal Strike Price Options Weighted Average Grant Date Fair Value Nominal Strike Price Options Weighted Average Grant Date Fair Value Nominal Strike Price Options Weighted Average Grant Date Fair Value Nominal Strike Price Options Weighted Average Grant Date Fair Value (in thousands, except weighted average grant date fair value) Outstanding, beginning of period 11,182 $ 8.44 11,240 $ 8.41 9,752 $ 7.90 9,182 $ 5.16 Granted 3,493 13.93 184 9.58 4,247 9.34 3,097 9.66 Exercised (3,798 ) 5.43 (150 ) 7.36 (2,617 ) 7.21 (2,239 ) 3.21 Cancelled (418 ) 11.69 (92 ) 8.61 (142 ) 9.37 (288 ) 6.69 Outstanding, end of period 10,459 $ 11.24 11,182 $ 8.44 11,240 $ 8.41 9,752 $ 7.90 Exercisable, end of period 1,434 $ 5.47 1,054 $ 3.65 1,136 $ 6.11 1,986 $ 4.52 The following table summarizes the Company’s market-priced stock option activity: Year Ended Three Months Ended Years Ended December 31, December 31, September 30, 2019 2018 2018 2017 Market Strike Price Options Weighted Average Exercise Price Market Strike Price Options Weighted Average Exercise Price Market Strike Price Options Weighted Average Exercise Price Market Strike Price Options Weighted Average Exercise Price (in thousands, except weighted average grant date fair value) Outstanding, beginning of period 2,889 $ 8.49 2,889 $ 8.49 2,174 $ 8.28 1,452 $ 5.80 Granted 602 14.82 — — 785 9.65 830 9.62 Exercised (654 ) 2.32 — — (70 ) 9.03 (108 ) 1.15 Cancelled (1 ) 3.89 — — — — — — Outstanding, end of period 2,836 $ 9.60 2,889 $ 8.49 2,889 $ 8.49 2,174 $ 8.28 Exercisable, end of period 620 $ 4.99 461 $ 6.90 257 $ 8.74 — — The weighted average per share fair value of market priced options granted during the year ended December 31, 2019 and years ended September 30, 2017 and 2018 was $14.82, $5.98, and $6.00, respectively. No market priced options were granted in the three months ended December 31, 2018. The aggregate intrinsic value of the stock options exercised in the year ended December 31, 2019 was $52.9 million. The aggregate intrinsic value of the stock options exercised in the three months ended December 31, 2018 was $1.6 million. The aggregate intrinsic value of stock options exercised in the years ended September 30, 2018, and 2017 was $ 30.7 22.9 4.6 4.3 102.01 92.2 12.5 Valuation and Expense Recognition of Share-Based Awards The fair value of stock option awards that do not contain a market condition is estimated using the Black-Scholes option-pricing model. The estimated fair value of each stock option is then expensed over the requisite service period, which is generally the vesting period. The determination of fair value using the Black-Scholes model is affected by the Company’s ADS price as well as assumptions regarding a number of complex and subjective variables, including expected ADS price volatility, risk-free interest rate, expected dividends and projected employee stock option exercise behaviors. Stock options granted during the year ended December 31, 2019, three months ended December 31, 2018 and the years ended September 30, 2018 and 2017 were valued using the Black-Scholes option-pricing model with the following weighted-average assumptions: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 Expected volatility 56 % 58 % 63 % 69 % Risk-free interest rate 2.56 % 2.70 % 2.30 % 1.93 % Expected dividend yield 0 % 0 % 0 % 0 % Expected life of options in years 6.50 6.50 6.50 6.50 The Company estimates its stock price volatility based using a combination of historical stock price volatility and the average implied volatility of options traded in the open market. The risk-free interest rate assumption is based on observed interest rates for the appropriate term of the Company’s stock options. The Company has never declared or paid dividends and has no plans to do so in the foreseeable future. The expected option life assumption is estimated using the simplified method prescribed by ASC 718 and is based on the mid-point between vest date and expiration date since the Company does not have sufficient exercise history to estimate expected option life of historical grants. Compensation expense for share-based awards based on a service condition is recognized only for those awards that are ultimately expected to vest. An estimated forfeiture rate has been applied to unvested awards for the purpose of calculating compensation cost. Forfeitures were estimated based on historical experience. These estimates are revised, if necessary, in future periods if actual forfeitures differ from the estimates. Changes in forfeiture estimates impact compensation cost in the period in which the change in estimate occurs. Compensation expense for share-based awards with graded, service-based vesting conditions is recognized over the requisite service period using the accelerated attribution method. The table below summarizes the total share-based compensation expense included in the Company’s statements of operations for the periods presented: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 (in thousands) Research and development $ 9,757 $ 6,887 $ 9,385 $ 5,239 Sales, general and administrative 35,468 2,382 22,242 10,240 45,225 $ 9,269 $ 31,627 $ 15,479 For the year ended December 31, 2019, $2.8 million of share-based compensation related to manufacturing operations was capitalized into inventory. For the three months ended December 31, 2018, $0.4 million of share-based compensation related to manufacturing operations was capitalized into inventory. Share-based compensation related to manufacturing operations capitalized into inventory for the years ended September 30, 2018 and 2017 were negligible. As of December 31, 2019, total compensation cost related to non-vested stock options not yet recognized was approximately $45.2 million, which is expected to be recognized over the next 42 months (10 months on a weighted average basis).

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Retirement Plans	Note 8: Retirement Plans The Company operates defined contribution retirement plans in the U.S. and U.K. for the benefit of all qualifying employees. The Company makes discretionary contributions to these plans and contributed $4.6 million, $0.9 million, $3.3 million, and $2.5 million

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Note 9: Income Taxes Income (loss) before income taxes is as follows: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 (in thousands) United States $ 22,822 $ 1,487 $ 12,041 $ 3,725 United Kingdom (32,025 ) (73,659 ) (303,411 ) (175,216 ) $ (9,203 ) $ (72,172 ) $ (291,370 ) $ (171,491 ) The components of income tax (benefit) expense are as follows: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 (in thousands) Current U.S. federal $ 7,397 $ 945 $ 3,885 $ 2,676 U.S. state and local 2,117 54 229 62 United Kingdom — — — — Total Current $ 9,514 $ 999 $ 4,114 $ 2,738 Deferred U.S. federal $ (6,372 ) $ (1,166 ) $ (263 ) $ (3,685 ) U.S. state and local (3,326 ) (99 ) (54 ) (85 ) United Kingdom — — — — Total Deferred $ (9,698 ) $ (1,265 ) $ (317 ) $ (3,770 ) Total income tax (benefit) expense $ (184 ) $ (266 ) $ 3,797 $ (1,032 ) As of December 31, 2019, December 31, 2018, September 30, 2018, and September 30, 2017, respectively, the tax effects of temporary differences and carryforwards that give rise to deferred tax assets and liabilities were as follows: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 (in thousands) Deferred tax assets: Net operating losses $ 106,421 $ 94,999 $ 94,570 $ 46,379 Research and development tax credits 668 180 180 506 Share-based compensation 14,515 10,057 8,745 7,496 Accrued expenses 3,268 2,275 2,320 1,787 Capitalized costs 1,688 3,219 — — Operating lease liabilities 1,837 — — — Rebates and allowances 5,172 136 — — Depreciation 279 — — — Other 428 689 291 199 Total gross deferred tax assets, net of valuation allowance 134,276 111,555 106,106 56,367 Valuation allowance (114,525 ) (101,606 ) (97,462 ) (46,126 ) 19,751 9,949 8,644 10,241 Deferred tax liabilities: Depreciation — $ (1,229 ) $ (1,310 ) $ (2,220 ) Operating lease assets (1,628 ) — — — Deferred revenue — — — (1,216 ) Total gross deferred tax liabilities (1,628 ) (1,229 ) (1,310 ) (3,436 ) Net of deferred tax assets and liabilities $ 18,123 $ 8,720 $ 7,334 $ 6,805 A valuation allowance of $114.5 million, $101.6 million, $97.5 million, and $46.1 million at December 31, 2019, December 31, 2018, September 30, 2018 and 2017, respectively, has been recognized to offset net deferred tax assets where realization of such assets is uncertain. The valuation allowances are primarily related to deferred tax assets for operating loss carryforwards and temporary differences related to share-based compensation expense of the Company’s U.K. operations. The following table reconciles the Company’s effective tax rate to the United Kingdom statutory rate: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 Tax, computed at the U.K. statutory rate 19.0 % 19.0 % 19.0 % 19.5 % Non-deductible expenses (5.2 %) (0.2 %) (0.1 %) (0.6 %) U.S. research tax credits, net 39.3 % 0.4 % 0.9 % 1.6 % Surrender of R&D expenditures for U.K. research tax credits, net (1.9 %) — (0.1 %) (5.7 %) Foreign Derived Intangible Income 6.8 % 0.8 % — — Share-based compensation 61.2 % 0.2 % 0.9 % 2.1 % Changes in valuation allowances (96.2 %) (19.6 %) (20.5 %) (16.2 %) State rate change 13.5 % — — — Current/Deferred tax rate differential (21.4 %) — — — Overseas profits taxed at different rates (13.9 %) (0.1 %) (0.3 %) — Remeasurement of deferred taxes from 2017 Tax Act 0.0 % — (1.0 %) — Other 0.8 % (0.1 %) (0.1 %) (0.1 %) Effective income tax rate 2.0 % 0.4 % (1.3 %) 0.6 % The Company is headquartered in the United Kingdom and has subsidiaries in the United Kingdom, United States, Europe, and Australia. The Company incurs tax losses in the United Kingdom. The weighted-average U.K. corporate tax rate for the year ended December 31, 2019, three months ended December 31, 2018, and years ended September 30, 2018, and 2017 was 19.0%, 19.0%, 19.0%, and 19.5%, respectively. The United Kingdom’s 2016 Finance Bill, which was enacted on September 15, 2016, contained reductions in corporation tax to 19% from April 1, 2017 and 17% from April 1, 2020. The Company used a 17% tax rate as of December 31, 2019 in respect of the measurement of deferred taxes arising in the United Kingdom, which reflects the currently enacted tax rate based upon the anticipated timing of the unwinding of the deferred tax balances. As of December 31, 2019, the Company had U.K. net operating loss carryforwards of approximately $626.0 million. Unsurrendered U.K. tax losses and tax credit carryforwards can be carried forward indefinitely to be offset against future taxable profits, however this is restricted to an annual £5 million allowance in each standalone company or group and above this allowance, there will be a 50% restriction in the profits that can be covered by losses brought forward. The Company’s subsidiary in the United States has generated taxable profits due to the commercialization of Epidiolex in the United States and service agreements between the Company’s subsidiaries in the United States and the United Kingdom. The U.S. federal corporate tax rate for the year ended December 31, 2019, three months ended December 31, 2018, and years ended September 30, 2018 and 2017 was 21.0%, 21.0%, 24.5%, and 35%, respectively. The U.S. federal statutory tax rate has decreased due to U.S. tax reform which was enacted in December 2017. The impact of income taxes outside of the United States and United Kingdom are not significant. The Company’s tax returns are subject to examination in the U.K. and U.S. The Company is no longer subject to examinations by tax authorities for tax years ended September 30, 2017 and prior in the United Kingdom. The Company’s U.K. income tax returns have been submitted to Her Majesty’s Revenue and Customs through the period ended December 31, 2018 and may be subject to audit until December 31, 2020. The Company is subject to examinations by U.S. Federal tax authorities for tax years ended December 31, 2018 and September 30, 2018, 2017, and 2016, and by state authorities for the tax years ended December 31, 2018 and September 30, 2018, 2017, 2016, and 2015. The California Franchise Tax Board has initiated an income tax audit of the Company’s U.S. subsidiary for tax years ended September 30, 2017, 2016, and 2015. Unrecognized tax benefits arise when the estimated benefit recorded in the financial statements differs from the amounts taken or expected to be taken in a tax return because of the uncertainties described above. The Company’s total amount of unrecognized tax benefits was $2.4 million, $1.9 million, $1.8 million, and $1.1 million as of December 31, 2019, December 31, 2018, September 30, 2018 and 2017, respectively. The Company’s policy is to recognize interest and penalties related to uncertain tax positions as a component of income tax expense and unrecognized tax benefits. The amounts accrued for interest and penalty charges as of December 31, 2019, December 31, 2018, September 30, 2018 and 2017 were not significant. If recognized, $2.4 million would affect the effective tax rate. The Company does not anticipate that the amount of unrecognized tax benefits as of December 31, 2019 will significantly change within the next twelve months. The reconciliation of the beginning and ending amount of unrecognized tax benefits was as follows: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 (in thousands) Balance, beginning of period $ 1,943 $ 1,826 $ 1,134 $ 884 Additions for tax positions related to current year 416 34 771 453 Additions for tax positions related to prior years 32 83 46 18 Reduction for tax positions related to prior years — — (125 ) (221 ) Balance, end of period $ 2,391 $ 1,943 $ 1,826 $ 1,134

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 10: Commitments and Contingencies Landlord Financing In 2013, the Company entered into an agreement with its landlord for the construction of a new production facility. In conjunction with agreement, the Company’s landlord provided $13.1 million of funding to the Company for the internal fit out of the production facility. The repayment of this landlord financing takes the form of quarterly rent payments over a 15-year period that commenced in May 2016. The landlord financing liability is accounted for at amortized cost using the effective interest method at a rate of 7.0%. As of December 31, 2019 and 2018, the total landlord financing liability balance was $9.7 million and $10.0 million, respectively and included in “other current liabilities” and “other liabilities” in the Company’s consolidated balance sheets. Legal Proceedings As of December 31, 2019, the Company was not a party to any material legal proceedings. The Company is not aware of any other proceedings or claims that it believes will have, individually or in the aggregate, a material adverse effect on its business, financial condition or results of operations.

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	Note 11: Leases The Company leases buildings, land, equipment, and automobiles. Additionally, the Company has growing and cultivation contracts that contain embedded facility leases. The Company determines if an arrangement is a lease or contains a lease at contract inception. For contracts that are or contain leases, the Company records right-of-use (ROU) lease assets and lease liabilities at lease commencement based on the present value of lease payments over the lease term. The lease term includes renewal option periods when those options are reasonably certain to be exercised. The present value of lease payments is calculated using the Company’s incremental collateralized borrowing rate unless an implicit rate is readily determinable. ROU lease assets include any upfront payments Leases are classified at lease commencement as either operating leases or finance leases. Operating lease assets are included in non-current assets and operating lease liabilities are included in other current liabilities and operating lease liabilities in our c onsolidated balance sheets. Operating lease cost is recognized on a straight-line basis over the lease term. Finance lease assets are included in property, plant and equipment, net, and finance lease liabilities are included in other current liabilities and finance lease liabilities in our consolidated balance sheets. Finance lease cost is recognized as depreciation expense of fixed assets and interest expense on finance lease liabilities. Leases with an initial term of 12 months or less are not recorded in the consolidated balance sheets and expense for these leases is recognized on a straight-line basis over the lease term. The Company’s lease costs consist of the following: Year Ended December 31, 2019 (in thousands) Lease cost Operating lease cost (1) $ 7,446 Finance lease cost Amortization of leased assets 383 Interest on lease liabilities 403 Total lease cost $ 8,232 (1) For the year ended December 31, 2019, approximately $2.7 million of operating and finance lease cost related to manufacturing operations was capitalized into inventory. The following table summarizes cash flow information related to the Company’s lease obligations: Year Ended December 31, 2019 (in thousands) Operating cash used for operating leases $ 7,081 Operating cash used for finance leases $ 403 Financing cash used for finance leases $ 389 In the year ended December 31, 2019, $7.6 million of operating lease assets were exchanged for lease liabilities related to newly commenced leases. The following table summarizes the Company’s lease assets and liabilities: As of December 31, 2019 (in thousands) Lease assets Operating lease assets $ 24,916 Finance lease assets 5,571 Total lease assets $ 30,487 Lease liabilities Current Operating lease liabilities 5,902 Finance lease liabilities 305 Non-current Operating lease liabilities 21,650 Finance lease liabilities 5,573 Total lease liabilities $ 33,430 The following table summarizes other supplemental information related to the Company’s lease obligations: As of December 31, 2019 Weighted average remaining lease term (years) Operating leases 7.2 Finance leases 14.2 Weighted average discount rate Operating leases 5.5 % Finance leases 7.6 % The Company’s future minimum annual lease payments under operating and finance leases as of December 31, 2019 are as follows: Operating Leases Finance Leases (in thousands) 2020 5,900 729 2021 5,498 729 2022 4,599 721 2023 3,782 718 2024 3,701 718 Thereafter 11,437 6,173 Total lease payments $ 34,917 $ 9,788 Future cash lease incentives 746 — Less amounts representing interest 6,619 3,910 Total lease obligations $ 27,552 $ 5,878 Prior to January 1, 2019, the Company accounted for leases under the previous U.S. GAAP lease guidance, Accounting Standards Codification Topic 840, Leases. Rent expense for operating leases was $1.8 million and $5.7 million for the three months ended December 31, 2018 and year ended September 30, 2018, respectively. The aggregate future minimum rent payments under leases in effect as of December 31, 2018 were $6.4 million in 2019, $6.9 million in 2020, $5.7 million in 2021, $4.2 million in 2022, $2.8 million in 2023, and $11.8 million thereafter.

Sale of Priority Review Voucher

Sale of Priority Review Voucher	12 Months Ended
	Dec. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Sale of Priority Review Voucher	Note 12: Sale of Priority Review Voucher In April 2019, the Company sold the rare pediatric disease PRV it received from the FDA in connection with the United States approval of Epidiolex to Biohaven Pharmaceutical Holding Ltd. for consideration of $105.0 million. The net proceeds of $104.1 million from the sale of the PRV was recognized as a gain on the sale of an intangible asset within other income on the consolidated statements of operations, as the PRV did not have a carrying value on the Company’s consolidated balance sheet at the time of sale.

Financial Statements and Supple

Financial Statements and Supplementary Data (Unaudited)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Data [Abstract]
Financial Statements and Supplementary Data (Unaudited)	Note 13: Financial Statements and Supplementary Data (Unaudited) The following interim financial information reflects all normal recurring adjustments necessary to fairly present the Company’s quarterly financial results. The summarized quarterly data for the year ended December 31, 2019, three months ended December 31, 2018, and year ended September 30, 2018 are as follows: March 31, June 30, September 30, December 31, 2019 2019 2019 2019 (in thousands, except share and per share amounts) Revenue $ 39,247 $ 72,038 $ 90,971 $ 109,076 Operating loss (51,337 ) (29,322 ) (17,658 ) (20,108 ) Net (loss) income attributable to ordinary shareholders (50,064 ) 79,748 (13,757 ) (24,946 ) Net (loss) income per ordinary share, basic (0.14 ) 0.21 (0.04 ) (0.07 ) Net (loss) income per ordinary share, diluted (0.14 ) 0.21 (0.04 ) (0.07 ) Weighted average shares outstanding, basic 369,823 371,712 372,246 372,447 Weighted average shares outstanding, diluted 369,823 377,435 372,246 372,447 December 31, March 31, June 30, September 30, December 31, 2017 2018 2018 2018 2018 (in thousands, except share and per share amounts) Revenue $ 3,992 $ 3,041 $ 3,284 $ 2,420 $ 6,654 Operating loss (58,548 ) (68,242 ) (81,406 ) (80,607 ) (73,344 ) Net loss attributable to ordinary shareholders (61,816 ) (69,461 ) (84,011 ) (79,879 ) (71,906 ) Net loss per ordinary share, basic and diluted (0.20 ) (0.20 ) (0.25 ) (0.23 ) (0.20 ) Weighted average shares outstanding, basic and diluted 313,730 340,252 340,457 341,302 366,458

Transition Period

Transition Period	12 Months Ended
	Dec. 31, 2019
Transition Period [Abstract]
Transition Period	Note 14: Transition Period The Company is presenting audited financial statements for the three months ended December 31, 2018. The following tables provide certain unaudited comparative financial information for the same period of the prior year. Three Months Ended December 31, 2018 2017 (in thousands, except share and per share amounts) Revenues Product net sales $ 6,617 $ 2,220 Other revenue 37 1,772 Total revenues 6,654 3,992 Operating expenses Cost of product sales 1,829 1,171 Research and development 29,086 36,195 Selling, general and administrative 49,083 25,174 Total operating expenses 79,998 62,540 Loss from operations (73,344 ) (58,548 ) Interest income 2,449 604 Interest expense (295 ) (314 ) Foreign exchange (loss) gain (982 ) 160 Loss before income taxes (72,172 ) (58,098 ) Income tax (benefit) expense (266 ) 3,718 Net loss $ (71,906 ) $ (61,816 ) Net loss per common share, basic and diluted $ (0.20 ) $ (0.20 ) Weighted average common shares outstanding, basic and diluted 366,458 313,730 F-29 Three Months Ended December 31, 2018 2017 (in thousands) Cash flows from operating activities Net loss $ (71,906 ) $ (61,816 ) Adjustments to reconcile net loss to net cash used in operating activities: Foreign exchange loss (gain) 742 (180 ) Stock-based compensation 9,683 5,592 Depreciation and amortization 2,534 2,163 Deferred income taxes (1,265 ) (1,152 ) Other — 8 Changes in operating assets and liabilities: Accounts receivable, net (2,125 ) (223 ) Inventory (14,460 ) 378 Prepaid expenses and other current assets (3,635 ) (516 ) Other assets (47 ) (166 ) Accounts payable (1,211 ) (1,802 ) Current tax liabilities 878 4,898 Accrued liabilities 5,942 3,004 Other current liabilities 93 (2,071 ) Long-term liabilities 317 325 Net cash used in operating activities (74,460 ) (51,558 ) Cash flows from investing activities Additions to property, plant and equipment (18,687 ) (7,748 ) Additions to capitalized software (63 ) (993 ) Proceeds from disposal of property, plant and equipment — — Net cash used in investing activities (18,750 ) (8,741 ) Cash flows from financing activities Proceeds from issuance of ordinary shares, net of issuance costs 324,638 297,932 Proceeds from exercise of stock options — 1 Payments on build-to-suit financing obligation — (26 ) Payments on capital leases (40 ) (39 ) Payments on landlord financing obligation (130 ) (125 ) Net cash provided by (used in) financing activities 324,468 297,743 Effect of exchange rate changes on cash 5,326 (371 ) Net increase (decrease) in cash and cash equivalents 236,584 237,073 Cash and cash equivalents at beginning of period 354,913 322,154 Cash and cash equivalents at end of period $ 591,497 $ 559,227

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Change of Fiscal Year	Change of Fiscal Year We changed our fiscal year end to December 31 from September 30, effective December 31, 2018. This annual report is for the year ended December 31, 2019.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States (U.S. GAAP) requires management to make estimates and assumptions that affect the reported amounts in the consolidated financial statements and accompanying notes. Actual results could differ from these estimates.
Foreign Currency Translation	Foreign Currency Translation The financial position and results of operations of the Company’s non-U.S. subsidiaries are generally determined using local currency as the functional currency. Assets and liabilities of these subsidiaries are translated at the exchange rate in effect at each year end. Income statement accounts are translated at the average rate of exchange prevailing during the year. Adjustments arising from the use of differing exchange rates from period to period are included in accumulated other comprehensive loss in stockholders’ equity. Foreign currency transaction gains and losses are included in “foreign exchange loss” in the Company’s consolidated statements of operations.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity date of three months or less to be cash equivalents.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying values of the Company’s financial instruments, consisting of cash and cash equivalents, trade receivables, interest and other receivables, and accounts payable and accrued liabilities, approximate fair value due to the relative short-term nature of these instruments.
Accounts Receivable	Accounts Receivable Accounts receivable are recorded net of customer allowances for prompt payment discounts, chargebacks, and doubtful accounts. Allowances for prompt payment discounts and chargebacks are based on contractual terms. The Company estimates the allowance for doubtful accounts based on existing contractual payment terms, actual payment patterns of its customers and individual customer circumstances. As of December 31, 2019, the allowance for doubtful accounts was $0.3 million. At December 31, 2018, the Company determined that an allowance for doubtful accounts was not required and no accounts were written off during the period.
Inventory	Inventory Inventory is stated at the lower of cost or estimated net realizable value. The Company uses a combination of standard and actual costing methodologies to determine the cost basis for its inventories which approximates actual cost. Inventory is valued on a first-in, first-out basis. The Company reduces its inventory to net realizable value for potentially excess, dated or obsolete inventory based on an analysis of forecasted demand compared to quantities on hand, as well as product shelf life. Our inventory production process includes the cultivation of botanical raw material. Because of the duration of the cultivation process, a portion of our inventory will not be sold within one year. Consistent with the practice in other industries that cultivate botanical raw materials, all inventory is classified as a current asset. The Company capitalizes inventory costs associated with its products upon regulatory approval when, based on management’s judgment, future commercialization is considered probable and the future economic benefit is expected to be realized; otherwise, such costs are expensed. Prior to FDA approval of Epidiolex, all costs related to the manufacturing of Epidiolex were charged to research and development expense in the period incurred.
Property, Plant, and Equipment	Property, Plant, and Equipment Property, plant, and equipment are recorded at cost and depreciated over their estimated useful lives using the straight-line method. Leasehold improvements are amortized over the shorter of their estimated useful lives or the term of the lease by use of the straight-line method. The estimated useful lives for buildings and leasehold improvements range from 4 to 20 years. The estimated useful lives of machinery and equipment range from 3 to 20 years. Construction-in-process reflects amounts incurred for property, equipment or improvements that have not been placed in service. Maintenance and repair costs are expensed as incurred. When assets are retired or sold, the assets and accumulated depreciation are removed from the respective accounts and any gain or loss is recognized.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by a comparison of the carrying amount of an asset to estimated future operating cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset.
Goodwill	Goodwill Goodwill represents the excess of purchase price over fair value of net assets acquired in a business combination and is not amortized. Goodwill is subject to impairment testing at least annually or when a triggering event occurs that could indicate a potential impairment. We performed the annual assessment for goodwill impairment in December of 2019, noting no impairment
Revenue Recognition	Revenue Recognition The Company recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of Accounting Standards Codification (ASC) Topic 606, Revenue from Contracts with Customers (Topic 606), the entity performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. Revenue for the Company’s product sales has not been adjusted for the effects of a financing component as the Company expects, at contract inception, that the period between when the Company’s transfers control of the product and when the Company receives payment will be one year or less. Product shipping and handling costs are included in cost of product sales.
Product Net Sales	Epidiolex Product Net Sales Epidiolex was approved by the FDA in June 2018. Subsequent to the approval by the FDA, the United States Drug Enforcement Agency (DEA) took action to change the classification of Epidiolex from a Schedule I controlled substance to a Schedule V controlled substance, thereby allowing Epidiolex to be prescribed and distributed in the United States. On November 1, 2018, the Company launched sales of Epidiolex to specialty pharmacies (SPs) and specialty distributors (SDs). The Company recognizes revenue from product sales upon receipt of product at the SPs and SDs, the date at which the control is transferred, net of the following allowances which are reflected either as a reduction to the related account receivable or as an accrued liability, depending on how the allowance is settled: Distribution Fees : Distribution fees include distribution service fees paid to the SPs and SDs based on a contractually fixed percentage of the wholesale acquisition cost (WAC), and prompt payment discounts. Distribution fees are recorded as an offset to revenue based on contractual terms at the time revenue from the sale is recognized. Rebates : Allowances for rebates include mandated discounts under the Medicaid Drug Rebate Program and the Medicare Part D prescription drug benefit, and contractual rebates with commercial payers. Rebates are amounts owed after the final dispensing of the product to a benefit plan participant and are based upon contractual agreements or statutory requirements. The allowance for rebates is based on contracted or statutory discount rates and expected utilization by benefit plan participants. The Company’s estimates for expected utilization of rebates is based on utilization data received from the SPs since product launch. Rebates are generally invoiced and paid in arrears so that the accrual balance consists of an estimate of the amount expected to be incurred for the current quarter’s activity, plus an accrual balance for prior quarters’ unpaid rebates. If actual future rebates vary from estimates, the Company may need to adjust prior period accruals, which would affect revenue in the period of adjustment. Chargebacks : Chargebacks are discounts and fees that relate to contracts with government and other entities purchasing from the SDs at a discounted price. The SDs charge back to the Company the difference between the price initially paid by the SDs and the discounted price paid to the SDs by these entities. The Company also incurs group purchasing organization fees for transactions through certain purchasing organizations. The Company estimates sales with these entities and accrues for anticipated chargebacks and organization fees, based on the applicable contractual terms. If actual future chargebacks vary from these estimates, the Company may need to adjust prior period accruals, which would affect revenue in the period of adjustment. Co-Payment Assistance : The Company offers co-payment assistance to commercially insured patients meeting certain eligibility requirements. Co-payment assistance is accrued for based on actual program participation and estimates of program redemption using data provided by third-party administrators. Product Returns : Consistent with industry practice, the Company offers the SPs and SDs limited product return rights for damages, shipment errors, and expiring product , provided that the return is within a specified period around the product expiration date as set forth in the applicable individual distribution agreement. The Company does not allow product returns for product that has been dispensed to a patient. As the Company receives inventory reports from the SPs and SDs and has the ability to control the amount of product that is sold to the SPs and SDs, it is able to make a reasonable estimate of future potential product returns based on this on-hand channel inventory data and sell-through data obtained from the SPs and SDs. In arriving at its estimate, the Company also considers historical product returns, the underlying product demand, and industry data specific to the specialty pharmaceutical distribution industry. On September 23, 2019, the Company announced that the European Commission (EC) approved the marketing authorization for Epidyolex™ (the trade name in Europe for Epidiolex) for use as adjunctive therapy of seizures associated with Lennox‑Gastaut syndrome (LGS) or Dravet syndrome, in conjunction with clobazam, for patients two years of age and older. The Company recognizes revenue from product sales in Europe upon delivery of the product, which is the point at which control of the goods is transferred to the customer. The Company recognizes revenue net of standard discounts and allowances, which are reflected as accrued liabilities. The Company also sells Epidiolex in certain markets outside of the United States under early access programs that enable patients to receive the product prior to regulatory approval. Revenue under early access programs is generally recognized when the product is delivered. The total amount deducted from gross sales for the allowances described above for the year ended December 31, 2019 was $63.3 million Sativex Product Net Sales Sales of Sativex are made outside of the United States for the treatment of spasticity due to multiple sclerosis, or MS, pursuant to license agreements with commercial partners. Under these license agreements, the Company sells fully labeled Sativex vials to its commercial partners for a contractually agreed price, which is generally based on percentages of the commercial partners’ in-market net selling price charged to end customers. Product net sales revenue related to Sativex shipments to commercial license partners is recognized when shipped, at which point the customer obtains control of the product. The Company commercializes Sativex in Australia and New Zealand through a consignment relationship with a local distributor. Product net sales revenues related to Sativex sales in Australia and New Zealand are recognized when the product is sold through to the end customer.
Other Revenue	Other Revenue The Company’s other revenue primarily consists of research and development fee revenue for services provided under a license agreement with Otsuka Pharmaceutical Co. Ltd (Otsuka) The research and development fee revenue is recognized at the time the underlying services are performed. The Sativex license agreements contain provisions for the Company to earn variable consideration in the form of regulatory milestone payments, sales-based milestone payments, and royalty payments. The Company has no further performance obligations related to the regulatory milestone payments and these amounts are recognized in accordance with Topic 606 when receipt of these payments becomes probable and there is no significant risk of revenue reversal. Revenue related to the sales-based milestone payments and product royalty payments are subject to the sales-based royalty exception under Topic 606 and is recognized when the underlying sales are made.
Research and Development Expenses	Research and Development Expenses Research and development expenses are charged to operations as incurred. Research and development expenses include, among other things, internal and external costs associated with preclinical development, pre-commercialization manufacturing expenses, and clinical trials. The Company accrues for costs incurred as the services are being provided by monitoring the status of the trial or services provided and the invoices received from its external service providers. In the case of clinical trials, a portion of the estimated cost normally relates to the projected cost to treat a patient in the trials, and this cost is recognized based on the number of patients enrolled in the trial. As actual costs become known, the Company adjusts its accruals accordingly. Research and development expense is presented net of reimbursements from reimbursable tax and expenditure credits from the U.K. government. The majority of the Company’s pipeline research, clinical trials management and the Epidiolex and Sativex chemistry and manufacturing controls development activities, which are generally carried out by a subsidiary in the U.K., are eligible for inclusion under the U.K tax and expenditure rebate schemes. For the year ended December 31, 2019, three months ended December 31, 2018 and years ended September 30, 2018 and 2017, the Company recorded $4.0 million, $0.8 million, $4.3 million, and $26.0 million, respectively, of U.K. tax and expenditure rebates as a component of research and development expense.
Concentration Risk	Concentration Risk Financial instruments, which potentially subject the Company to concentrations of credit risk, principally consist of cash, cash equivalents, investment securities, and accounts receivable. The Company’s cash and cash equivalents balances are primarily in depository accounts at major financial institutions in accordance with the Company’s investment policy. The Company’s investment policy defines allowable investments and establishes guidelines relating to credit quality, diversification, and maturities of its investments to preserve principal and maintain liquidity. Further, the Company specifies credit quality standards for its customers that are designed to limit the Company’s credit exposure to any single party. For the year ended December 31, 2019, the Company’s five largest customers represented approximately 85% of the Company’s product net sales and 86% of the Company’s accounts receivable balance as of December 31, 2019. For the three months ended December 31, 2018, the Company’s five largest customers represented approximately 71% of the Company’s product net sales and 75% of the Company’s accounts receivable balance as of December 31, 2018. For the years ended September 30, 2018 and 2017, product net sales consisted entirely of Sativex sales outside of the United States pursuant to license agreements with a small number of commercial partners.
Stock-based Compensation	Share-based Compensation The Company recognizes share-based compensation expense for grants of stock options under the Company's Long-Term Incentive Plans to employees and non-employee members of the Company's board of directors based on the grant-date fair value of those awards. The grant-date fair value of an award is generally recognized as compensation expense over the award's requisite service period. Expense related to awards with graded vesting is generally recognized over the vesting period using the accelerated attribution method. The Company uses the Black-Scholes model to compute the estimated fair value of stock option awards. Using this model, fair value is calculated based on assumptions with respect to (i) expected volatility of the Company's ADS price, (ii) the periods of time over which employees and members of the board of directors are expected to hold their options prior to exercise (expected lives), (iii) expected dividend yield on the ordinary shares, and (iv) risk-free interest rates. Share-based compensation expense also includes an estimate, which is made at the time of grant, of the number of awards that are expected to be forfeited. This estimate is revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates.
Income Taxes	Income Taxes The Company recognizes deferred tax assets and liabilities for temporary differences between the financial reporting basis and the tax basis of the Company's assets and liabilities along with net operating loss and tax credit carryovers. The Company records a valuation allowance against its deferred tax assets to reduce the net carrying value to an amount that it believes is more likely than not to be realized. When the Company establishes or reduces the valuation allowance against its deferred tax assets, its provision for income taxes will increase or decrease, respectively, in the period such determination is made. Valuation allowances against the Company’s deferred tax assets were $114.5 million and $101.6 million at December 31, 2019 and 2018, respectively. Changes in the valuation allowances are generally recognized in the provision for income taxes as a component of the estimated annual effective tax rate. Uncertain tax positions, for which management's assessment is that there is more than a 50% probability of sustaining the position upon challenge by a taxing authority based upon its technical merits, are subjected to certain recognition and measurement criteria. The Company re-evaluates uncertain tax positions and considers various factors, including, but not limited to, changes in tax law, the measurement of tax positions taken or expected to be taken in tax returns, and changes in facts or circumstances related to a tax position. The Company adjusts the level of the liability to reflect any subsequent changes in the relevant facts and circumstances surrounding the uncertain positions. The Company recognizes interest and penalties related to income tax matters in income tax expense.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing the net loss by the weighted average number of common shares outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share is computed by dividing the net loss by the weighted average number of common shares and common stock equivalents outstanding for the period determined using the treasury stock method. For purposes of this calculation, market-priced stock options are considered to be common stock equivalents but are not included in the calculations of diluted net loss per share for the periods presented as their effect would be anti-dilutive. Nominal strike-price options are considered common stock equivalents and are included in the calculation of basic weighted average shares outstanding once they have become vested. The Company incurred net losses for all periods presented and there were no reconciling items for potentially dilutive securities. More specifically, at December 31, 2019, December 31, 2018, and September 30, 2018, and 2017, options totaling approximately 11.8 million,
Segment and Geographic Reporting	Segment and Geographic Reporting Management has determined that the Company operates in one business segment which is the discovery, development and commercialization of novel therapeutics from its proprietary cannabinoid product platform in a broad range of disease areas. Revenues recorded in the year ended December 31, 2019, three months ended December 31, 2018, and years ended September 30, 2018, and 2017 were generated in the following geographical areas: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 (in thousands) United Kingdom 2,550 220 1,761 1,758 United States 288,164 4,669 1,560 121 Europe 16,516 1,131 6,882 5,447 Other 4,102 634 2,534 1,303 Total revenues $ 311,332 $ 6,654 $ 12,737 $ 8,629 Long-lived assets which include property, plant, and equipment were located as follows: December 31, 2019 2018 (in thousands) United Kingdom $ 123,207 $ 89,550 United States 4,558 1,282 Total long-lived assets $ 127,765 $ 90,832
Recently Issued Accounting Standards	Recently Issued Accounting Standards Accounting Standards Update (ASU) 2016-13, Measurement of Credit Losses on Financial Instruments: In June 2016, the FASB issued ASU 2016-13, which amends the impairment model by requiring entities to use a forward-looking approach based on expected losses to estimate credit losses on certain types of financial instruments, including trade receivables and available-for-sale debt securities. This guidance is effective for annual reporting periods beginning after December 15, 2019, including interim periods. The Company is finalizing the credit loss calculations and does not expect the adoption of this standard to have a significant impact on the Company’s consolidated financial statements. ASU 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes: In December 2019, the FASB issued ASU No. 2019-12, Simplifying the Accounting for Income Taxes, as part of its initiative to reduce complexity in accounting standards. The amendments in the ASU are effective for fiscal years beginning after December 15, 2020, including interim periods therein. Early adoption of the standard is permitted, including adoption in interim or annual periods for which financial statements have not yet been issued. We have not early adopted this ASU for 2019. The ASU is currently not expected to have a material impact on our consolidated financial statements. Recently Adopted Accounting Standards ASU 2016-02, Leases: On January 1, 2019, the Company adopted ASU 2016-02 using the modified retrospective method. This new accounting standard requires a lessee to recognize an asset and liability for most leases on its balance sheet. The Company elected the optional transition method that allowed for a cumulative-effect adjustment as of January 1, 2019 and did not restate previously reported results in the comparative periods. The Company also elected to adopt certain practical expedients allowed by the new standard, which among other things, allowed the Company to carry forward its historical lease classification. As a result of adoption of the new standard, the Company recorded operating lease assets and liabilities of approximately $20.5 million and $21.1 million, respectively, as of January 1, 2019. The operating lease liability was determined based on the present value of the remaining minimum rental payments and the operating lease asset was determined based on the value of the lease liability, adjusted for existing deferred rent balances, which were previously included in other current liabilities and other liabilities. Accounting for the Company’s finance leases remains substantially unchanged. As a result of the adoption of the new leasing accounting standard, the Company’s build-to-suit asset has been reclassified to buildings and the build-to-suit financing obligation has been reclassified to finance lease obligation in the consolidated balance sheets. In addition, the adoption of this new accounting standard resulted in increased qualitative and quantitative disclosures regarding the amount, timing, and uncertainty of cash flows arising from leases. For further details, see Note 11, Leases .

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Revenues by Geographic Areas	Revenues recorded in the year ended December 31, 2019, three months ended December 31, 2018, and years ended September 30, 2018, and 2017 were generated in the following geographical areas: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 (in thousands) United Kingdom 2,550 220 1,761 1,758 United States 288,164 4,669 1,560 121 Europe 16,516 1,131 6,882 5,447 Other 4,102 634 2,534 1,303 Total revenues $ 311,332 $ 6,654 $ 12,737 $ 8,629
Long-lived Assets Includes Property Plant and Equipment	Long-lived assets which include property, plant, and equipment were located as follows: December 31, 2019 2018 (in thousands) United Kingdom $ 123,207 $ 89,550 United States 4,558 1,282 Total long-lived assets $ 127,765 $ 90,832

Composition of Certain Balanc_2

Composition of Certain Balance Sheet Captions (Tables)	12 Months Ended
	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Schedule of Inventory	Inventory consisted of the following: December 31, 2019 2018 (in thousands) Raw materials $ 1,976 $ 676 Work in process 78,547 28,709 Finished goods 5,005 3,645 $ 85,528 $ 33,030
Schedule of Property, Plant and Equipment, Net	Property, plant and equipment, net, consisted of the following: December 31, 2019 2018 (in thousands) Buildings 4,725 4,573 Machinery and equipment 36,323 32,598 Leasehold improvements 42,744 36,004 Office and IT equipment 3,837 2,481 Construction-in-process 78,485 44,546 166,114 120,202 Accumulated depreciation (38,349 ) (29,370 ) $ 127,765 $ 90,832
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following: December 31, 2019 2018 (in thousands) Accrued compensation and benefits $ 25,469 $ 18,482 Accrued vendor fees 29,731 11,452 Clinical trial accruals 10,382 10,059 Accrued growing fees 3,818 2,717 Accrued sales rebates and discounts 22,995 628 Other 6,979 9,139 $ 99,374 $ 52,477
Schedule of Other Current Liabilities	Other current liabilities consisted of the following: December 31, 2019 2018 (in thousands) Finance lease liabilities $ 305 $ 400 Operating lease liabilities 5,902 — Landlord financing 595 539 Other 958 620 $ 7,760 $ 1,559
Schedule of Other Liabilities	Other liabilities consisted of the following: December 31, 2019 2018 (in thousands) Landlord financing obligation $ 9,152 $ 9,434 Other 2,279 648 $ 11,431 $ 10,082

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Nominal Strike Price Stock Option Activity	The following table summarizes the Company’s nominal strike price stock option activity: Year Ended Three Months Ended Years Ended December 31, December 31, September 30, 2019 2018 2018 2017 Nominal Strike Price Options Weighted Average Grant Date Fair Value Nominal Strike Price Options Weighted Average Grant Date Fair Value Nominal Strike Price Options Weighted Average Grant Date Fair Value Nominal Strike Price Options Weighted Average Grant Date Fair Value (in thousands, except weighted average grant date fair value) Outstanding, beginning of period 11,182 $ 8.44 11,240 $ 8.41 9,752 $ 7.90 9,182 $ 5.16 Granted 3,493 13.93 184 9.58 4,247 9.34 3,097 9.66 Exercised (3,798 ) 5.43 (150 ) 7.36 (2,617 ) 7.21 (2,239 ) 3.21 Cancelled (418 ) 11.69 (92 ) 8.61 (142 ) 9.37 (288 ) 6.69 Outstanding, end of period 10,459 $ 11.24 11,182 $ 8.44 11,240 $ 8.41 9,752 $ 7.90 Exercisable, end of period 1,434 $ 5.47 1,054 $ 3.65 1,136 $ 6.11 1,986 $ 4.52
Summary of Market Priced Stock Option Activity	The following table summarizes the Company’s market-priced stock option activity: Year Ended Three Months Ended Years Ended December 31, December 31, September 30, 2019 2018 2018 2017 Market Strike Price Options Weighted Average Exercise Price Market Strike Price Options Weighted Average Exercise Price Market Strike Price Options Weighted Average Exercise Price Market Strike Price Options Weighted Average Exercise Price (in thousands, except weighted average grant date fair value) Outstanding, beginning of period 2,889 $ 8.49 2,889 $ 8.49 2,174 $ 8.28 1,452 $ 5.80 Granted 602 14.82 — — 785 9.65 830 9.62 Exercised (654 ) 2.32 — — (70 ) 9.03 (108 ) 1.15 Cancelled (1 ) 3.89 — — — — — — Outstanding, end of period 2,836 $ 9.60 2,889 $ 8.49 2,889 $ 8.49 2,174 $ 8.28 Exercisable, end of period 620 $ 4.99 461 $ 6.90 257 $ 8.74 — —
Summary of Stock Options Granted Valued with Weighted-Average Assumptions	Stock options granted during the year ended December 31, 2019, three months ended December 31, 2018 and the years ended September 30, 2018 and 2017 were valued using the Black-Scholes option-pricing model with the following weighted-average assumptions: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 Expected volatility 56 % 58 % 63 % 69 % Risk-free interest rate 2.56 % 2.70 % 2.30 % 1.93 % Expected dividend yield 0 % 0 % 0 % 0 % Expected life of options in years 6.50 6.50 6.50 6.50
Summary of Share-based Compensation Expense Included in Statements of Operations	The table below summarizes the total share-based compensation expense included in the Company’s statements of operations for the periods presented: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 (in thousands) Research and development $ 9,757 $ 6,887 $ 9,385 $ 5,239 Sales, general and administrative 35,468 2,382 22,242 10,240 45,225 $ 9,269 $ 31,627 $ 15,479

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Summary of Income (Loss) Before Income Taxes	Income (loss) before income taxes is as follows: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 (in thousands) United States $ 22,822 $ 1,487 $ 12,041 $ 3,725 United Kingdom (32,025 ) (73,659 ) (303,411 ) (175,216 ) $ (9,203 ) $ (72,172 ) $ (291,370 ) $ (171,491 )
Components of Income Tax (Benefit) Expense	The components of income tax (benefit) expense are as follows: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 (in thousands) Current U.S. federal $ 7,397 $ 945 $ 3,885 $ 2,676 U.S. state and local 2,117 54 229 62 United Kingdom — — — — Total Current $ 9,514 $ 999 $ 4,114 $ 2,738 Deferred U.S. federal $ (6,372 ) $ (1,166 ) $ (263 ) $ (3,685 ) U.S. state and local (3,326 ) (99 ) (54 ) (85 ) United Kingdom — — — — Total Deferred $ (9,698 ) $ (1,265 ) $ (317 ) $ (3,770 ) Total income tax (benefit) expense $ (184 ) $ (266 ) $ 3,797 $ (1,032 )
Significant Components of Deferred Tax Assets and Liabilities	As of December 31, 2019, December 31, 2018, September 30, 2018, and September 30, 2017, respectively, the tax effects of temporary differences and carryforwards that give rise to deferred tax assets and liabilities were as follows: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 (in thousands) Deferred tax assets: Net operating losses $ 106,421 $ 94,999 $ 94,570 $ 46,379 Research and development tax credits 668 180 180 506 Share-based compensation 14,515 10,057 8,745 7,496 Accrued expenses 3,268 2,275 2,320 1,787 Capitalized costs 1,688 3,219 — — Operating lease liabilities 1,837 — — — Rebates and allowances 5,172 136 — — Depreciation 279 — — — Other 428 689 291 199 Total gross deferred tax assets, net of valuation allowance 134,276 111,555 106,106 56,367 Valuation allowance (114,525 ) (101,606 ) (97,462 ) (46,126 ) 19,751 9,949 8,644 10,241 Deferred tax liabilities: Depreciation — $ (1,229 ) $ (1,310 ) $ (2,220 ) Operating lease assets (1,628 ) — — — Deferred revenue — — — (1,216 ) Total gross deferred tax liabilities (1,628 ) (1,229 ) (1,310 ) (3,436 ) Net of deferred tax assets and liabilities $ 18,123 $ 8,720 $ 7,334 $ 6,805
Reconciliation of Effective Tax Rate	The following table reconciles the Company’s effective tax rate to the United Kingdom statutory rate: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 Tax, computed at the U.K. statutory rate 19.0 % 19.0 % 19.0 % 19.5 % Non-deductible expenses (5.2 %) (0.2 %) (0.1 %) (0.6 %) U.S. research tax credits, net 39.3 % 0.4 % 0.9 % 1.6 % Surrender of R&D expenditures for U.K. research tax credits, net (1.9 %) — (0.1 %) (5.7 %) Foreign Derived Intangible Income 6.8 % 0.8 % — — Share-based compensation 61.2 % 0.2 % 0.9 % 2.1 % Changes in valuation allowances (96.2 %) (19.6 %) (20.5 %) (16.2 %) State rate change 13.5 % — — — Current/Deferred tax rate differential (21.4 %) — — — Overseas profits taxed at different rates (13.9 %) (0.1 %) (0.3 %) — Remeasurement of deferred taxes from 2017 Tax Act 0.0 % — (1.0 %) — Other 0.8 % (0.1 %) (0.1 %) (0.1 %) Effective income tax rate 2.0 % 0.4 % (1.3 %) 0.6 %
Reconciliation of Unrecognized Tax Benefits	The reconciliation of the beginning and ending amount of unrecognized tax benefits was as follows: Year Ended December 31, Three Months Ended December 31, Years Ended September 30, 2019 2018 2018 2017 (in thousands) Balance, beginning of period $ 1,943 $ 1,826 $ 1,134 $ 884 Additions for tax positions related to current year 416 34 771 453 Additions for tax positions related to prior years 32 83 46 18 Reduction for tax positions related to prior years — — (125 ) (221 ) Balance, end of period $ 2,391 $ 1,943 $ 1,826 $ 1,134

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Summary of Lease Costs	The Company’s lease costs consist of the following: Year Ended December 31, 2019 (in thousands) Lease cost Operating lease cost (1) $ 7,446 Finance lease cost Amortization of leased assets 383 Interest on lease liabilities 403 Total lease cost $ 8,232 (1)
Summary of Cash Flow Information Related to Lease Obligations	The following table summarizes cash flow information related to the Company’s lease obligations: Year Ended December 31, 2019 (in thousands) Operating cash used for operating leases $ 7,081 Operating cash used for finance leases $ 403 Financing cash used for finance leases $ 389
Summary of Lease Assets and Liabilities	The following table summarizes the Company’s lease assets and liabilities: As of December 31, 2019 (in thousands) Lease assets Operating lease assets $ 24,916 Finance lease assets 5,571 Total lease assets $ 30,487 Lease liabilities Current Operating lease liabilities 5,902 Finance lease liabilities 305 Non-current Operating lease liabilities 21,650 Finance lease liabilities 5,573 Total lease liabilities $ 33,430
Summary of Other Supplemental Information Related to Lease Obligations	The following table summarizes other supplemental information related to the Company’s lease obligations: As of December 31, 2019 Weighted average remaining lease term (years) Operating leases 7.2 Finance leases 14.2 Weighted average discount rate Operating leases 5.5 % Finance leases 7.6 %
Summary of Future Minimum Annual Lease Payments Under Operating and Finance Leases	The Company’s future minimum annual lease payments under operating and finance leases as of December 31, 2019 are as follows: Operating Leases Finance Leases (in thousands) 2020 5,900 729 2021 5,498 729 2022 4,599 721 2023 3,782 718 2024 3,701 718 Thereafter 11,437 6,173 Total lease payments $ 34,917 $ 9,788 Future cash lease incentives 746 — Less amounts representing interest 6,619 3,910 Total lease obligations $ 27,552 $ 5,878

Financial Statements and Supp_2

Financial Statements and Supplementary Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Data [Abstract]
Summary of Quarterly Data	The summarized quarterly data for the year ended December 31, 2019, three months ended December 31, 2018, and year ended September 30, 2018 are as follows: March 31, June 30, September 30, December 31, 2019 2019 2019 2019 (in thousands, except share and per share amounts) Revenue $ 39,247 $ 72,038 $ 90,971 $ 109,076 Operating loss (51,337 ) (29,322 ) (17,658 ) (20,108 ) Net (loss) income attributable to ordinary shareholders (50,064 ) 79,748 (13,757 ) (24,946 ) Net (loss) income per ordinary share, basic (0.14 ) 0.21 (0.04 ) (0.07 ) Net (loss) income per ordinary share, diluted (0.14 ) 0.21 (0.04 ) (0.07 ) Weighted average shares outstanding, basic 369,823 371,712 372,246 372,447 Weighted average shares outstanding, diluted 369,823 377,435 372,246 372,447 December 31, March 31, June 30, September 30, December 31, 2017 2018 2018 2018 2018 (in thousands, except share and per share amounts) Revenue $ 3,992 $ 3,041 $ 3,284 $ 2,420 $ 6,654 Operating loss (58,548 ) (68,242 ) (81,406 ) (80,607 ) (73,344 ) Net loss attributable to ordinary shareholders (61,816 ) (69,461 ) (84,011 ) (79,879 ) (71,906 ) Net loss per ordinary share, basic and diluted (0.20 ) (0.20 ) (0.25 ) (0.23 ) (0.20 ) Weighted average shares outstanding, basic and diluted 313,730 340,252 340,457 341,302 366,458

Transition Period (Tables)

Transition Period (Tables)	12 Months Ended
	Dec. 31, 2019
Transition Period [Abstract]
Unaudited Comparative Financial Information Statements of Operations	The following tables provide certain unaudited comparative financial information for the same period of the prior year. Three Months Ended December 31, 2018 2017 (in thousands, except share and per share amounts) Revenues Product net sales $ 6,617 $ 2,220 Other revenue 37 1,772 Total revenues 6,654 3,992 Operating expenses Cost of product sales 1,829 1,171 Research and development 29,086 36,195 Selling, general and administrative 49,083 25,174 Total operating expenses 79,998 62,540 Loss from operations (73,344 ) (58,548 ) Interest income 2,449 604 Interest expense (295 ) (314 ) Foreign exchange (loss) gain (982 ) 160 Loss before income taxes (72,172 ) (58,098 ) Income tax (benefit) expense (266 ) 3,718 Net loss $ (71,906 ) $ (61,816 ) Net loss per common share, basic and diluted $ (0.20 ) $ (0.20 ) Weighted average common shares outstanding, basic and diluted 366,458 313,730 F-29
Unaudited Comparative Financial Information Statements of Cash Flows	Three Months Ended December 31, 2018 2017 (in thousands) Cash flows from operating activities Net loss $ (71,906 ) $ (61,816 ) Adjustments to reconcile net loss to net cash used in operating activities: Foreign exchange loss (gain) 742 (180 ) Stock-based compensation 9,683 5,592 Depreciation and amortization 2,534 2,163 Deferred income taxes (1,265 ) (1,152 ) Other — 8 Changes in operating assets and liabilities: Accounts receivable, net (2,125 ) (223 ) Inventory (14,460 ) 378 Prepaid expenses and other current assets (3,635 ) (516 ) Other assets (47 ) (166 ) Accounts payable (1,211 ) (1,802 ) Current tax liabilities 878 4,898 Accrued liabilities 5,942 3,004 Other current liabilities 93 (2,071 ) Long-term liabilities 317 325 Net cash used in operating activities (74,460 ) (51,558 ) Cash flows from investing activities Additions to property, plant and equipment (18,687 ) (7,748 ) Additions to capitalized software (63 ) (993 ) Proceeds from disposal of property, plant and equipment — — Net cash used in investing activities (18,750 ) (8,741 ) Cash flows from financing activities Proceeds from issuance of ordinary shares, net of issuance costs 324,638 297,932 Proceeds from exercise of stock options — 1 Payments on build-to-suit financing obligation — (26 ) Payments on capital leases (40 ) (39 ) Payments on landlord financing obligation (130 ) (125 ) Net cash provided by (used in) financing activities 324,468 297,743 Effect of exchange rate changes on cash 5,326 (371 ) Net increase (decrease) in cash and cash equivalents 236,584 237,073 Cash and cash equivalents at beginning of period 354,913 322,154 Cash and cash equivalents at end of period $ 591,497 $ 559,227

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) shares in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)shares	Dec. 31, 2019USD ($)Segmentshares	Sep. 30, 2018USD ($)shares	Sep. 30, 2017USD ($)shares	Jan. 01, 2019USD ($)
Summary Of Significant Accounting Policies [Line Items]
Accounts receivable written off		$ 0
Allowance for doubtful accounts	$ 300,000		$ 300,000
Goodwill Impairment charges	0
Amount deducted from gross sales for allowances			63,300,000
Income tax expenditure rebates of research and development expense		800,000	4,000,000	$ 4,300,000	$ 26,000,000
Deferred tax assets, valuation allowance	114,525,000	$ 101,606,000	$ 114,525,000	$ 97,462,000	$ 46,126,000
Number of business segment | Segment			1
Operating lease assets	24,916,000		$ 24,916,000			$ 20,500,000
Lease liabilities	$ 33,430,000		$ 33,430,000			$ 21,100,000
Ordinary Shares
Summary Of Significant Accounting Policies [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share | shares		13	11.8	13	9.9
Customer Concentration Risk | Product Net Sales
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage		71.00%	85.00%
Customer Concentration Risk | Accounts Receivable
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage		75.00%	86.00%
Buildings and Leasehold Improvements | Minimum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life			4 years
Buildings and Leasehold Improvements | Maximum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life			20 years
Machinery and Equipment | Minimum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life			3 years
Machinery and Equipment | Maximum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life			20 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Revenues by Geographical Areas (Details) - USD ($) $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Information [Line Items]
Total revenues	$ 109,076	$ 90,971	$ 72,038	$ 39,247	$ 6,654	$ 2,420	$ 3,284	$ 3,041	$ 3,992	$ 311,332	$ 12,737	$ 8,629
United Kingdom
Segment Reporting Information [Line Items]
Total revenues					220					2,550	1,761	1,758
United States
Segment Reporting Information [Line Items]
Total revenues					4,669					288,164	1,560	121
Europe
Segment Reporting Information [Line Items]
Total revenues					1,131					16,516	6,882	5,447
Other
Segment Reporting Information [Line Items]
Total revenues					$ 634					$ 4,102	$ 2,534	$ 1,303

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Long-lived Assets Includes Property Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total long-lived assets	$ 127,765	$ 90,832
United Kingdom
Segment Reporting Information [Line Items]
Total long-lived assets	123,207	89,550
United States
Segment Reporting Information [Line Items]
Total long-lived assets	$ 4,558	$ 1,282

Sativex License Agreements - Ad

Sativex License Agreements - Additional Information (Details) - Sativex License Agreements - USD ($)	Dec. 31, 2019	Dec. 31, 2017
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent future milestone payment		$ 10,000,000
Potential sale based milestone		$ 30,000,000
Accrued milestones contingent payments	$ 0

Composition of Certain Balanc_3

Composition of Certain Balance Sheet Captions - Schedule of Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Raw materials	$ 1,976	$ 676
Work in process	78,547	28,709
Finished goods	5,005	3,645
Inventory	$ 85,528	$ 33,030

Composition of Certain Balanc_4

Composition of Certain Balance Sheet Captions - Schedule of Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 166,114	$ 120,202
Accumulated depreciation	(38,349)	(29,370)
Property, plant and equipment, net	127,765	90,832
Buildings
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	4,725	4,573
Machinery and Equipment
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	36,323	32,598
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	42,744	36,004
Office and IT Equipment
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	3,837	2,481
Construction-in-Process
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 78,485	$ 44,546

Composition of Certain Balanc_5

Composition of Certain Balance Sheet Captions - Additional Information (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Balance Sheet Related Disclosures [Abstract]
Depreciation of property and equipment	$ 2,200,000	$ 8,000,000	$ 8,500,000	$ 7,000,000
Retired fully depreciated property, plant and equipment	$ 0	$ 0	$ 500,000	$ 1,800,000

Composition of Certain Balanc_6

Composition of Certain Balance Sheet Captions - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Accrued compensation and benefits	$ 25,469	$ 18,482
Accrued vendor fees	29,731	11,452
Clinical trial accruals	10,382	10,059
Accrued growing fees	3,818	2,717
Accrued sales rebates and discounts	22,995	628
Other	6,979	9,139
Accrued liabilities	$ 99,374	$ 52,477

Composition of Certain Balanc_7

Composition of Certain Balance Sheet Captions - Schedule of Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Other Liabilities Current [Abstract]
Finance lease liabilities	$ 305	$ 400
Operating lease liabilities	5,902
Landlord financing	595	539
Other	958	620
Other current liabilities	$ 7,760	$ 1,559

Composition of Certain Balanc_8

Composition of Certain Balance Sheet Captions - Schedule of Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Landlord financing obligation	$ 9,152	$ 9,434
Other	2,279	648
Other liabilities	$ 11,431	$ 10,082

Stockholder's Equity - Addition

Stockholder's Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended	12 Months Ended
	Oct. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Sep. 30, 2018
Class Of Stock [Line Items]
ADS price per share	$ 158	$ 115
Proceeds from issuance of shares	$ 324.6	$ 297.9
American Depositary Shares ("ADSs")
Class Of Stock [Line Items]
Shares issued	2,185,000	2,760,000
Common Stock
Class Of Stock [Line Items]
Shares issued	26,220,000	33,120,000	26,220,000	33,120,000

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2018USD ($)shares	Dec. 31, 2019USD ($)$ / sharesshares	Sep. 30, 2018USD ($)$ / sharesshares	Sep. 30, 2017USD ($)$ / sharesshares	Dec. 31, 2019£ / shares	Dec. 31, 2018£ / shares	Mar. 14, 2017shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares issued | shares	0	602,000	785,000	830,000
Exercise price | £ / shares					£ 0.001	£ 0.001
Aggregate intrinsic value stock option exercised	$ 1.6	$ 52.9	$ 30.7	$ 22.9
Weighted average remaining contractual life of option outstanding		4 years 7 months 6 days
Weighted average remaining contractual life of option exercisable		4 years 3 months 18 days
Share price | $ / shares		$ 8.50
Aggregate intrinsic value of options outstanding		$ 92.2
Aggregate intrinsic value of options exercisable		12.5
Inventory
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation related to manufacturing operations capitalized	$ 0.4	$ 2.8
American Depositary Shares ("ADSs")
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share price | $ / shares		$ 102.01
2017 LTIP Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grant expiration date		Mar. 13, 2022
Number of shares issued | shares		10,300,000
2017 LTIP Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized for issuance | shares							15,000,000
2017 LTIP Plan | American Depositary Shares ("ADSs")
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized for issuance | shares							1,300,000
Market Priced Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average per share fair value of market priced options granted | $ / shares		$ 14.82	$ 5.98	$ 6
Non-Vested Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total compensation cost not yet recognized		$ 45.2
Total compensation cost expected period of recognition		42 months
Total compensation cost weighted-average basis period		10 months

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Nominal Strike Price Stock Option Activity (Details) - $ / shares shares in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Nominal Strike Price Options, Outstanding, beginning of period	11,240	11,182	9,752	9,182
Nominal Strike Price Options, Granted	184	3,493	4,247	3,097
Nominal Strike Price Options, Exercised	(150)	(3,798)	(2,617)	(2,239)
Nominal Strike Price Options, Cancelled	(92)	(418)	(142)	(288)
Nominal Strike Price Options, Outstanding, end of period	11,182	10,459	11,240	9,752
Nominal Strike Price Options, Exercisable, end of period	1,054	1,434	1,136	1,986
Weighted Average Grant Date Fair Value, Outstanding, beginning of period	$ 8.41	$ 8.44	$ 7.90	$ 5.16
Weighted Average Grant Date Fair Value, Granted	9.58	13.93	9.34	9.66
Weighted Average Grant Date Fair Value, Exercised	7.36	5.43	7.21	3.21
Weighted Average Grant Date Fair Value, Cancelled	8.61	11.69	9.37	6.69
Weighted Average Grant Date Fair Value, Outstanding, end of period	8.44	11.24	8.41	7.90
Weighted Average Grant Date Fair Value, Exercisable, end of period	$ 3.65	$ 5.47	$ 6.11	$ 4.52

Share-Based Compensation - Su_2

Share-Based Compensation - Summary of Market Priced Stock Option Activity (Details) - $ / shares shares in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Market Strike Price Options, Outstanding, beginning of period	2,889	2,889	2,174	1,452
Market Strike Price Options, Granted	0	602	785	830
Market Strike Price Options, Exercised	0	(654)	(70)	(108)
Market Strike Price Options, Cancelled	0	(1)	0	0
Market Strike Price Options, Outstanding, end of period	2,889	2,836	2,889	2,174
Market Strike Price Options, Exercisable, end of period	461	620	257
Weighted Average Exercise Price, Outstanding, beginning of period	$ 8.49	$ 8.49	$ 8.28	$ 5.80
Weighted Average Exercise Price, Granted	0	14.82	9.65	9.62
Weighted Average Exercise Price, Exercised	0	2.32	9.03	1.15
Weighted Average Exercise Price, Cancelled	0	3.89	0	0
Weighted Average Exercise Price, Outstanding, end of period	8.49	9.60	8.49	$ 8.28
Weighted Average Exercise Price, Exercisable, end of period	$ 6.90	$ 4.99	$ 8.74

Share-Based Compensation - Su_3

Share-Based Compensation - Summary of Stock Options Granted Valued with Weighted-Average Assumptions (Details)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected volatility	58.00%	56.00%	63.00%	69.00%
Risk-free interest rate	2.70%	2.56%	2.30%	1.93%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Expected life of options in years	6 years 6 months	6 years 6 months	6 years 6 months	6 years 6 months

Share-Based Compensation - Su_4

Share-Based Compensation - Summary of Share-based Compensation Expense Included in Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 9,269	$ 45,225	$ 31,627	$ 15,479
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	6,887	9,757	9,385	5,239
Sales, General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 2,382	$ 35,468	$ 22,242	$ 10,240

Retirement Plans - Additional I

Retirement Plans - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Defined Contribution Retirement Plan
Defined Contribution Plan Disclosure [Line Items]
Employer discretionary contribution amount to retirement plans	$ 0.9	$ 4.6	$ 3.3	$ 2.5

Income Taxes - Summary of Incom

Income Taxes - Summary of Income (Loss) Before Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
United States	$ 1,487	$ 22,822	$ 12,041	$ 3,725
United Kingdom	(73,659)	(32,025)	(303,411)	(175,216)
Income (loss) before income taxes	$ (72,172)	$ (9,203)	$ (291,370)	$ (171,491)

Income Taxes - Components of In

Income Taxes - Components of Income Tax (Benefit) Expense (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Current
U.S. federal	$ 945		$ 7,397	$ 3,885	$ 2,676
U.S. state and local	54		2,117	229	62
Total Current	999		9,514	4,114	2,738
Deferred
U.S. federal	(1,166)		(6,372)	(263)	(3,685)
U.S. state and local	(99)		(3,326)	(54)	(85)
Total Deferred	(1,265)		(9,698)	(317)	(3,770)
Total income tax (benefit) expense	$ (266)	$ 3,718	$ (184)	$ 3,797	$ (1,032)

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2017
Deferred tax assets:
Net operating losses	$ 106,421	$ 94,999	$ 94,570	$ 46,379
Research and development tax credits	668	180	180	506
Share-based compensation	14,515	10,057	8,745	7,496
Accrued expenses	3,268	2,275	2,320	1,787
Capitalized costs	1,688	3,219
Operating lease liabilities	1,837
Rebates and allowances	5,172	136
Depreciation	279
Other	428	689	291	199
Total gross deferred tax assets, net of valuation allowance	134,276	111,555	106,106	56,367
Valuation allowance	(114,525)	(101,606)	(97,462)	(46,126)
Total deferred tax assets, net of valuation allowance	19,751	9,949	8,644	10,241
Deferred tax liabilities:
Depreciation		(1,229)	(1,310)	(2,220)
Operating lease assets	(1,628)
Deferred revenue				(1,216)
Total gross deferred tax liabilities	(1,628)	(1,229)	(1,310)	(3,436)
Net of deferred tax assets and liabilities	$ 18,123	$ 8,720	$ 7,334	$ 6,805

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) $ in Thousands, £ in Millions	Apr. 01, 2020	Apr. 01, 2017	Dec. 31, 2018USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2019GBP (£)	Sep. 30, 2016USD ($)
Income Taxes [Line Items]
Deferred tax assets, valuation allowance			$ 101,606	$ 114,525	$ 97,462	$ 46,126
Weighted-average corporate tax rate			0.40%	2.00%	(1.30%)	0.60%
Unrecognized Tax Benefits			$ 1,943	$ 2,391	$ 1,826	$ 1,134		$ 884
Unrecognized tax benefits would impact effective tax rate, if recognized				$ 2,400
U.S. Federal Tax Authorities | Tax Year 2018 [Member]
Income Taxes [Line Items]
Tax year under examination				2018
U.S. Federal Tax Authorities | Tax Year 2017 [Member]
Income Taxes [Line Items]
Tax year under examination				2017
U.S. Federal Tax Authorities | Tax Year 2016 [Member]
Income Taxes [Line Items]
Tax year under examination				2016
State Authorities | Tax Year 2018 [Member]
Income Taxes [Line Items]
Tax year under examination				2018
State Authorities | Tax Year 2017 [Member]
Income Taxes [Line Items]
Tax year under examination				2017
State Authorities | Tax Year 2016 [Member]
Income Taxes [Line Items]
Tax year under examination				2016
State Authorities | Tax Year 2015 [Member]
Income Taxes [Line Items]
Tax year under examination				2015
United Kingdom
Income Taxes [Line Items]
Tax, computed at the UK statutory rate			19.00%	19.00%	19.00%	19.50%
Tax rate used for measurement of deferred tax assets				17.00%
Net operating loss carryforwards				$ 626,000
Unsurrendered tax losses and tax credit carryforwards to be offset, restricted valuation | £							£ 5
Percentage of restriction in profits covered by losses above restricted valuation amount				50.00%			50.00%
United Kingdom | Scenario, Plan
Income Taxes [Line Items]
Tax, computed at the UK statutory rate	17.00%	19.00%
United States
Income Taxes [Line Items]
Weighted-average corporate tax rate			21.00%	21.00%	24.50%	35.00%

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Effective Tax Rate (Details)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Investments Owned Federal Income Tax Note [Line Items]
Non-deductible expenses	(0.20%)	(5.20%)	(0.10%)	(0.60%)
Foreign Derived Intangible Income	0.80%	6.80%
Share-based compensation	0.20%	61.20%	0.90%	2.10%
Changes in valuation allowances	(19.60%)	(96.20%)	(20.50%)	(16.20%)
State rate change		13.50%
Current/Deferred tax rate differential		(21.40%)
Overseas profits taxed at different rates	(0.10%)	(13.90%)	(0.30%)
Remeasurement of deferred taxes from 2017 Tax Act		0.00%	(1.00%)
Other	(0.10%)	0.80%	(0.10%)	(0.10%)
Effective income tax rate	0.40%	2.00%	(1.30%)	0.60%
United Kingdom
Investments Owned Federal Income Tax Note [Line Items]
Tax, computed at the U.K. statutory rate	19.00%	19.00%	19.00%	19.50%
Surrender of R&D expenditures for U.K. research tax credits, net		(1.90%)	(0.10%)	(5.70%)
United States
Investments Owned Federal Income Tax Note [Line Items]
Research tax credits, net	0.40%	39.30%	0.90%	1.60%
Effective income tax rate	21.00%	21.00%	24.50%	35.00%

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Balance, beginning of period	$ 1,826	$ 1,943	$ 1,134	$ 884
Additions for tax positions related to current year	34	416	771	453
Additions for tax positions related to prior years	83	32	46	18
Reduction for tax positions related to prior years			(125)	(221)
Balance, end of period	$ 1,943	$ 2,391	$ 1,826	$ 1,134

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended
	May 31, 2016	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2013
Commitments And Contingencies Disclosure [Abstract]
Build-to-suit financing obligation				$ 13.1
Build to suit financing obligation rent payments period	15 years
Build to suit financing obligation effective interest rate	7.00%
Build to suit financing, landlord financing obligation		$ 9.7	$ 10

Leases - Summary of Lease Costs

Leases - Summary of Lease Costs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Lease cost
Operating lease cost	$ 7,446
Finance lease cost
Amortization of leased assets	383
Interest on lease liabilities	403
Total lease cost	$ 8,232

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018
Leases [Abstract]
Operating and finance lease cost related to manufacturing operations capitalized into inventory		$ 2.7
Operating lease assets were exchanged for lease liabilities		$ 7.6
Rent expense for operating leases	$ 1.8		$ 5.7
Leases payments, 2019	6.4
Leases payments, 2020	6.9
Leases payments, 2021	5.7
Leases payments, 2022	4.2
Leases payments, 2023	2.8
Leases payments, thereafter	$ 11.8

Leases - Summary of Cash Flow I

Leases - Summary of Cash Flow Information Related to Lease Obligations (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Leases [Abstract]
Operating cash used for operating leases		$ 7,081
Operating cash used for finance leases		403
Financing cash used for finance leases	$ 40	$ 389	$ 276	$ 261

Leases - Summary of Lease Asset

Leases - Summary of Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Lease assets
Operating lease assets	$ 24,916	$ 20,500
Finance lease assets	5,571
Total lease assets	30,487
Current
Operating lease liabilities	5,902
Finance lease liabilities	305		$ 400
Non-current
Operating lease liabilities	21,650
Finance lease liabilities	5,573		$ 5,690
Total lease liabilities	$ 33,430	$ 21,100

Leases - Summary of Other Suppl

Leases - Summary of Other Supplemental Information Related to Lease Obligations (Details)	Dec. 31, 2019
Weighted average remaining lease term (years)
Operating leases	7 years 2 months 12 days
Finance leases	14 years 2 months 12 days
Weighted average discount rate
Operating leases	5.50%
Finance leases	7.60%

Leases - Summary of Future Mini

Leases - Summary of Future Minimum Annual Lease Payments Under Operating and Finance Leases (Details) $ in Thousands	Dec. 31, 2019USD ($)
Leases [Abstract]
Operating Leases, 2020	$ 5,900
Operating Leases, 2021	5,498
Operating Leases, 2022	4,599
Operating Leases, 2023	3,782
Operating Leases, 2024	3,701
Operating Leases, Thereafter	11,437
Operating Leases, Total lease payments	34,917
Operating Leases, Future cash lease incentives	746
Operating Leases, Less amounts representing interest	6,619
Operating Leases, Total lease obligations	27,552
Finance Leases, 2020	729
Finance Leases, 2021	729
Finance Leases, 2022	721
Finance Leases, 2023	718
Finance Leases, 2024	718
Finance Leases, Thereafter	6,173
Finance Leases, Total lease payments	9,788
Finance Leases, Less amounts representings interest	3,910
Finance Leases, Total lease obligations	$ 5,878

Sale of Priority Review Vouch_2

Sale of Priority Review Voucher - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Apr. 30, 2019	Dec. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Consideration for sale of priority review voucher	$ 105,000
Proceeds from sale of priority review voucher	$ 104,100	$ 104,117

Financial Statements and Supp_3

Financial Statements and Supplementary Data (Unaudited) - Summary of Quarterly Data (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Quarterly Financial Data [Abstract]
Revenue	$ 109,076	$ 90,971	$ 72,038	$ 39,247	$ 6,654	$ 2,420	$ 3,284	$ 3,041	$ 3,992	$ 311,332	$ 12,737	$ 8,629
Operating loss	(20,108)	(17,658)	(29,322)	(51,337)	(73,344)	(80,607)	(81,406)	(68,242)	(58,548)	(118,425)	(288,803)	(166,161)
Net (loss) income attributable to ordinary shareholders	$ (24,946)	$ (13,757)	$ 79,748	$ (50,064)	$ (71,906)	$ (79,879)	$ (84,011)	$ (69,461)	$ (61,816)	$ (9,019)	$ (295,167)	$ (170,459)
Net (loss) income per ordinary share, basic	$ (0.07)	$ (0.04)	$ 0.21	$ (0.14)
Net (loss) income per ordinary share, diluted	$ (0.07)	$ (0.04)	$ 0.21	$ (0.14)
Weighted average shares outstanding, basic	372,447	372,246	371,712	369,823
Weighted average shares outstanding, diluted	372,447	372,246	377,435	369,823
Net loss per ordinary share, basic and diluted					$ (0.20)	$ (0.23)	$ (0.25)	$ (0.20)	$ (0.20)	$ (0.02)	$ (0.88)	$ (0.56)
Weighted average common shares outstanding, basic and diluted					366,458	341,302	340,457	340,252	313,730	371,580	333,936	305,826

Transition Period - Unaudited C

Transition Period - Unaudited Comparative Financial Information Statements of Operations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Revenues
Total revenues	$ 109,076	$ 90,971	$ 72,038	$ 39,247	$ 6,654	$ 2,420	$ 3,284	$ 3,041	$ 3,992	$ 311,332	$ 12,737	$ 8,629
Operating expenses
Cost of product sales					1,829				1,171	27,199	5,986	4,521
Research and development					29,086				36,195	142,678	153,736	112,249
Selling, general and administrative					49,083				25,174	259,880	141,818	58,020
Total operating expenses					79,998				62,540	429,757	301,540	174,790
Loss from operations	(20,108)	(17,658)	(29,322)	(51,337)	(73,344)	(80,607)	(81,406)	(68,242)	(58,548)	(118,425)	(288,803)	(166,161)
Interest income					2,449				604	8,464	3,645	2,063
Interest expense					(295)				(314)	(1,087)	(1,249)	(951)
Foreign exchange (loss) gain					(982)				160	(2,272)	(4,963)	(6,442)
Loss before income taxes					(72,172)				(58,098)	(9,203)	(291,370)	(171,491)
Income tax (benefit) expense					(266)				3,718	(184)	3,797	(1,032)
Net loss	$ (24,946)	$ (13,757)	$ 79,748	$ (50,064)	$ (71,906)	$ (79,879)	$ (84,011)	$ (69,461)	$ (61,816)	$ (9,019)	$ (295,167)	$ (170,459)
Net loss per common share, basic and diluted					$ (0.20)	$ (0.23)	$ (0.25)	$ (0.20)	$ (0.20)	$ (0.02)	$ (0.88)	$ (0.56)
Weighted average common shares outstanding, basic and diluted					366,458	341,302	340,457	340,252	313,730	371,580	333,936	305,826
Product Net Sales
Revenues
Total revenues					$ 6,617				$ 2,220	$ 310,331	$ 10,469	$ 7,957
Other Revenue
Revenues
Total revenues					$ 37				$ 1,772	$ 1,001	$ 2,268	$ 672

Transition Period - Unaudited_2

Transition Period - Unaudited Comparative Financial Information Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities
Net loss	$ (71,906)	$ (61,816)	$ (9,019)	$ (295,167)	$ (170,459)
Adjustments to reconcile net loss to net cash used in operating activities:
Foreign exchange loss (gain)	742	(180)	2,709	4,917	9,280
Stock-based compensation	9,683	5,592	48,030	31,627	15,479
Depreciation and amortization	2,534	2,163	9,240	9,290	7,054
Deferred income taxes	(1,265)	(1,152)	(9,698)	(317)	(3,770)
Gain from sale of priority review voucher			(104,117)
Other		8	39	241	1,554
Changes in operating assets and liabilities:
Accounts receivable, net	(2,125)	(223)	(44,623)	(804)	(277)
Inventory	(14,460)	378	(51,125)	(13,646)	5
Prepaid expenses and other current assets	(3,635)	(516)	(9,831)	14,489	(12,471)
Other assets	(47)	(166)	3,888	(564)
Accounts payable	(1,211)	(1,802)	805	2,238	3,171
Current tax liabilities	878	4,898	(963)	54	57
Accrued liabilities	5,942	3,004	43,110	16,507	1,253
Other current liabilities	93	(2,071)
Long-term liabilities	317	325
Other liabilities	410		(1,914)	(733)	150
Net cash used in operating activities	(74,460)	(51,558)	(123,469)	(231,868)	(148,974)
Cash flows from investing activities
Additions to property, plant and equipment	(18,687)	(7,748)	(40,386)	(31,362)	(19,285)
Additions to capitalized software	(63)	(993)	(2,102)	(2,042)	(812)
Proceeds from disposal of property, plant and equipment				517
Net cash provided by (used in) investing activities	(18,750)	(8,741)	61,629	(32,887)	(20,097)
Cash flows from financing activities
Proceeds from issuance of ordinary shares, net of issuance costs	324,638	297,932		297,931
Proceeds from exercise of stock options		1	2,878	621	122
Payments on build-to-suit financing obligation		(26)
Payments on capital leases	(40)	(39)
Payments on finance leases	(40)		(389)	(276)	(261)
Payments on landlord financing obligation	(130)	(125)	(543)	(522)	(1,074)
Net cash provided by (used in) financing activities	324,468	297,743	1,946	297,754	(1,213)
Effect of exchange rate changes on cash	5,326	(371)	5,330	(240)	8,993
Net increase (decrease) in cash and cash equivalents	236,584	237,073	(54,564)	32,759	(161,291)
Cash and cash equivalents at beginning of period	354,913	322,154	591,497	322,154	483,445
Cash and cash equivalents at end of period	$ 591,497	$ 559,227	$ 536,933	$ 354,913	$ 322,154