Sio Gene Therapies (SIOX) 10-Q 7 Nov 18 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Sep. 30, 2018	Nov. 05, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	Axovant Sciences Ltd.
Entity Central Index Key	1,636,050
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Amendment Flag	false
Current Fiscal Year End Date	--03-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		122,279,348
Document Fiscal Year Focus	2,019
Document Fiscal Period Focus	Q2
Entity Emerging Growth Company	true
Entity Small Business	false
Entity Ex Transition Period	true

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Mar. 31, 2018
Current assets:
Cash	$ 90,726	$ 154,337
Prepaid expenses and other current assets	4,095	2,174
Income tax receivable	1,530	1,751
Total current assets	96,351	158,262
Other non-current assets	4,324	0
Property and equipment, net	1,513	2,524
Total assets	102,188	160,786
Current liabilities:
Accounts payable	1,817	3,949
Due to RSL, RSI and RSG	2,859	1,011
Accrued expenses	24,315	31,862
Current portion of long-term debt	20,009	9,753
Total current liabilities	49,000	46,575
Long-term debt	33,309	42,925
Total liabilities	82,309	89,500
Commitments and contingencies (Note 11)
Shareholders’ equity:
Common shares, par value $0.00001 per share, 1,000,000,000 shares authorized, 122,175,480 and 107,788,074 issued and outstanding at September 30, 2018 and March 31, 2018, respectively	1	1
Additional paid-in capital	661,980	628,110
Accumulated deficit	(642,674)	(556,951)
Accumulated other comprehensive income	572	126
Total shareholders’ equity	19,879	71,286
Total liabilities and shareholders’ equity	$ 102,188	$ 160,786

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2018	Mar. 31, 2018
Common stock
Common shares par value (in dollars per share)	$ 0.00001	$ 0.00001
Common shares authorized (in shares)	1,000,000,000	1,000,000,000
Common shares issued (in shares)	122,175,480	107,788,074
Common shares outstanding (in shares)	122,175,480	107,788,074

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Operating expenses:
Research and development expenses	[1]	$ 21,502	$ 38,555	$ 58,920	$ 82,267
General and administrative expenses	[2]	10,622	30,112	22,376	51,630
Total operating expenses		32,124	68,667	81,296	133,897
Other expenses:
Interest expense		1,932	1,878	3,902	3,752
Other expense (income)		(315)	131	353	(226)
Loss before income tax expense		(33,741)	(70,676)	(85,551)	(137,423)
Income tax expense (benefit)		94	(1,590)	172	929
Net loss		$ (33,835)	$ (69,086)	$ (85,723)	$ (138,352)
Net loss per common share — basic and diluted (in dollars per share)		$ (0.28)	$ (0.64)	$ (0.75)	$ (1.29)
Weighted average common shares outstanding - basic and diluted (in shares)		120,863,455	107,593,609	114,362,408	107,000,519
Research and development expenses
Costs allocated		$ (3,069)	$ 2,257	$ (450)	$ 5,258
General and administrative expenses
Costs allocated		$ 772	$ 1,623	$ 2,074	$ 3,496
[1]	Includes total costs allocated from RSL, RSI and RSG of $(3,069) and $2,257 for the three months ended September 30, 2018 and 2017, respectively, and $(450) and $5,258 for the six months ended September 30, 2018 and 2017, respectively.
[2]	Includes total costs allocated from RSL, RSI and RSG of $772 and $1,623 for the three months ended September 30, 2018 and 2017, respectively, and $2,074 and $3,496 for the six months ended September 30, 2018 and 2017, respectively.

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Research and development expenses
Share-based compensation	$ (1,128)	$ 5,916	$ 1,389	$ 12,172
General and administrative expenses
Share-based compensation	$ 3,585	$ 9,424	$ 6,927	$ 18,768

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net loss	$ (33,835)	$ (69,086)	$ (85,723)	$ (138,352)
Other comprehensive income (loss):
Foreign currency translation adjustment	(113)	99	446	(250)
Total other comprehensive income (loss)	(113)	99	446	(250)
Comprehensive loss	$ (33,948)	$ (68,987)	$ (85,277)	$ (138,602)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Shareholders' Equity - 6 months ended Sep. 30, 2018 - USD ($) $ in Thousands	Total	Common Shares	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income	RSLPrivate Placement	RSLPrivate PlacementCommon Shares	RSLPrivate PlacementAdditional Paid-in Capital	Cowen and Company, LLCPrivate Placement	Cowen and Company, LLCPrivate PlacementCommon Shares	Cowen and Company, LLCPrivate PlacementAdditional Paid-in Capital
Beginning Balance (in shares) at Mar. 31, 2018		107,788,074
Beginning Balance at Mar. 31, 2018	$ 71,286	$ 1	$ 628,110	$ (556,951)	$ 126
Increase (Decrease) in Shareholders' Equity (Deficit)
Exercise of stock options (in shares)		95,742
Exercise of stock options	118		118
Shares issued (in shares)							14,285,714			5,950
Shares issued						$ 25,000		$ 25,000	$ 14		$ 14
Share-based compensation expense	11,004		11,004
Capital contribution — share-based compensation expense	(2,688)		(2,688)
Non-cash capital contribution received by ASG from RSI	422		422
Foreign currency translation adjustment	446				446
Net loss	(85,723)			(85,723)
Ending Balance (in shares) at Sep. 30, 2018		122,175,480
Ending Balance at Sep. 30, 2018	$ 19,879	$ 1	$ 661,980	$ (642,674)	$ 572

Condensed Consolidated Statem_5

Condensed Consolidated Statement of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net loss	$ (85,723)	$ (138,352)
Adjustments to reconcile net loss to net cash used in operating activities:
Disposal of fixed assets	9	0
Foreign currency translation adjustment	446	(250)
Share-based compensation	8,316	30,940
Depreciation and non-cash amortization	1,647	1,050
Deferred tax assets	0	2,709
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(1,921)	1,870
Other non-current assets	(4,324)	0
Accounts payable	(2,132)	(5,691)
Due to RSL, RSI and RSG	2,283	1,323
Accrued expenses	(7,547)	(1,002)
Income tax receivable	221	(2,155)
Net cash used in operating activities	(88,725)	(109,558)
Cash flows from investing activities:
Purchases of property and equipment	(18)	(3,643)
Net cash used in investing activities	(18)	(3,643)
Cash flows from financing activities:
Exercise of stock options	118	1,486
Cash proceeds from issuance of common shares, net of costs	25,014	134,515
Net cash provided by financing activities	25,132	136,001
Net change in cash	(63,611)	22,800
Cash—beginning of period	154,337	212,573
Cash—end of period	90,726	235,373
Non-cash financing activities:
Non-cash capital contribution received by ASG from RSI	422	0
Issuance of common stock upon exercise of warrant	$ 0	$ 2,594

Description of Business

Description of Business	6 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business Axovant Sciences Ltd., together with its wholly owned subsidiaries (the "Company"), is a clinical-stage gene therapy company focused on developing a pipeline of innovative product candidates for debilitating neurological and neuromuscular diseases such as Parkinson's disease, oculopharyngeal muscular dystrophy ("OPMD"), amyotrophic lateral sclerosis ("ALS"), frontotemporal dementia, and other indications. The Company is also developing nelotanserin for the treatment of Lewy body dementia ("LBD") and potentially other neurology and psychiatry indications. The Company is an exempted limited company incorporated under the laws of Bermuda in October 2014 under the name Roivant Neurosciences Ltd. The Company changed its name to Axovant Sciences Ltd. in March 2015 . The Company has six wholly owned subsidiaries: Axovant Holdings Limited ("AHL"), a direct wholly owned subsidiary of Axovant Sciences Ltd., was incorporated in England and Wales in August 2016; Axovant Sciences, Inc. ("ASI"), a direct wholly owned subsidiary of AHL, was incorporated in Delaware in February 2015; Axovant Sciences GmbH ("ASG"), a direct wholly owned subsidiary of AHL, was organized in Switzerland in August 2016; Axovant Sciences America, Inc. ("ASA"), a direct wholly owned subsidiary of AHL, was incorporated in Delaware in July 2017; and Axovant Treasury Holdings, Inc. ("ATH"), a direct wholly owned subsidiary of ASL and Axovant Treasury, Inc. ("ATI"), a direct wholly owned subsidiary of ATH, were each incorporated in Delaware in March 2018. ASG holds all of the Company's intellectual property rights and is the principal operating company for conducting the Company’s business. The Company's near-term focus is to develop its gene therapy product candidates AXO-Lenti-PD, a potential one-time treatment for Parkinson's disease, and AXO-AAV-OPMD, a potential one-time treatment for OPMD. The Company has initiated a clinical study of AXO-Lenti-PD in patients with Parkinson's disease and intends to initiate a clinical study of AXO-AAV-OPMD in patients with OPMD in the second half of 2019. Prior to the recent in-licensing of AXO-Lenti-PD in June 2018 and AXO-AAV-OPMD in July 2018, the Company's primary focus had been on developing nelotanserin, a selective inverse agonist of the 5-HT 2A receptor, and intepirdine, an antagonist of the 5-HT 6 receptor for which development had been terminated in January 2018. Topline data from the ongoing Phase 2 study of nelotanserin in REM Sleep Behavior Disorder ("RBD") in LBD patients is expected to be available in December 2018. The Company is evaluating the possibility of partnering or pursuing other strategic opportunities for nelotanserin. In October 2018, the Company discontinued its development plans for RVT-104 as a potential treatment for patients with Alzheimer's disease or dementia with Lewy bodies ("DLB"), which is a sub-type of LBD. From its inception, the Company has devoted substantially all of its efforts to organizing and staffing the Company, raising capital, acquiring product candidates and advancing its product candidates into clinical development. The Company has determined that it has one operating and reporting segment as it allocates resources and assesses financial performance on a consolidated basis. The Company does not expect to generate revenue unless and until it successfully completes development and obtains regulatory approval for one of its product candidates. The Company believes it currently has access to sufficient funds to meet its financial needs for at least the next 12 months. The Company will be required to obtain further funding through public or private offerings of its share capital, debt financing, collaboration and licensing arrangements or other sources as it advances its product candidates through preclinical and clinical development. Adequate additional funding may not be available to the Company on acceptable terms, or at all.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies (A) Basis of Presentation: The Company’s fiscal year ends on March 31, and its fiscal quarters end on June 30, September 30 and December 31. The accompanying interim unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States ("U.S. GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and disclosures required by U.S. GAAP for complete financial statements. These interim unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended March 31, 2018 the ("Annual Report"), filed with the Securities and Exchange Commission ("SEC") on June 11, 2018. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary to present fairly the financial position of the Company and its results of operations and cash flows for the interim periods presented have been included. Operating results for the three and six-months ended September 30, 2018 are not necessarily indicative of the results that may be expected for the year ending March 31, 2019, for any other interim period, or for any other future year. Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification ("ASC") and Accounting Standards Update ("ASU") issued by the Financial Accounting Standards Board ("FASB"). The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. The Company has no unconsolidated subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. There have been no significant changes in the Company’s accounting policies from those disclosed in its Annual Report. (B) Use of Estimates: The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company regularly evaluates estimates and assumptions related to the assets, liabilities, costs and expenses (including compensation expense) allocated to the Company under its services agreements with Roivant Sciences, Inc. ("RSI") and Roivant Sciences GmbH ("RSG"), each a wholly owned subsidiary of the Company’s parent company, RSL, as well as the evaluation of the Company's ability to continue as a going concern, contingent liabilities, share-based compensation and research and development costs. Specifically, the Company estimates the grant date fair value of stock option awards with only time-based vesting requirements using a Black-Scholes valuation model and uses a Monte Carlo Simulation method under the income approach to estimate the grant date fair value of stock option awards with market-based performance conditions. The Company bases its estimates and assumptions on historical experience and on various other factors that it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates. (C) Net Loss per Common Share: Basic net loss per common share is computed by dividing the net loss applicable to common shareholders by the weighted-average number of common shares outstanding during the period. Diluted net loss per common share is computed by dividing the net loss applicable to common shareholders by the diluted weighted-average number of common shares outstanding during the period calculated in accordance with the treasury stock method. Stock options to purchase approximately 15.8 million common shares were not included in the calculation of diluted weighted-average common shares outstanding for each of the three and six -months ended September 30, 2018 because they were anti-dilutive given the net loss of the Company. Stock options and a warrant which, combined, would enable the purchase of an aggregate of 5.4 million and 10.4 million common shares were not included in the calculation of diluted weighted-average common shares outstanding for the three and six -months ended September 30, 2017 , respectively, because they were anti-dilutive given the net loss of the Company. (D) Fair Value Measurements: The Company utilizes fair value measurement guidance prescribed by accounting standards to value its financial instruments. The guidance establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. Fair value is defined as the exchange price, or exit price, representing the amount that would be received from the sale of an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, the guidance establishes a three-tier fair value hierarchy that distinguishes among the following: • Level 1-Valuations are based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access. • Level 2-Valuations are based on quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active and models for which all significant inputs are observable, either directly or indirectly. • Level 3-Valuations are based on inputs that are unobservable (supported by little or no market activity) and significant to the overall fair value measurement. To the extent the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The Company’s financial instruments include cash, accounts payable and long-term debt. Cash and accounts payable are stated at their respective historical carrying amounts, which approximate fair value due to their short-term nature. The carrying value of the Company’s debt was $53.3 million as of September 30, 2018 and approximates fair value based on current interest rates for similar types of borrowings and is in Level 2 of the fair value hierarchy. See Note 5 for the actual book carrying value of the Company's long-term debt at September 30, 2018 . (E) Recent Accounting Pronouncements: In February 2016, the FASB issued ASU No. 2016-02, " Leases (Topic 842) " ("ASU No. 2016-02"), as well as ASU No. 2018-10, " Codification Improvements to Topic 842, Leases " and ASU No. 2018-11, " Leases (Topic 842): Targeted Improvements " in July 2018 (collectively, the "Lease Standards"), which relate to a comprehensive new lease standard that amends various aspects of existing accounting guidance for leases. The core principle of the Lease Standards will require lessees to present the assets and liabilities that arise from leases on their balance sheets. The Lease Standards are effective for annual periods beginning after December 15, 2018, and interim periods within fiscal years beginning after December 15, 2018. Early adoption is permitted. The Company has implemented a process to identify its outstanding lease portfolio and is currently evaluating its outstanding leases to determine the impact the Lease Standards will have on its consolidated financial statements. In January 2017, the FASB issued ASU 2017-01, " Business Combinations (Topic 805): Clarifying the Definition of a Business " ("ASU No. 2017-01"), which clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The Company adopted the provisions of ASU No. 2017-01 on April 1, 2018 on a prospective basis. The impact on the Company's consolidated financial statements and disclosures will depend on the facts and circumstances of any specific future transactions. See Note 3 for further information regarding the impact of the adoption of ASU No. 2017-01 on the license agreements executed during the three and six-months ended September 30, 2018. In February 2018, the FASB issued ASU No. 2018-02, " Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income" ("ASU No. 2018-02"). ASU No. 2018-02 allows companies to reclassify stranded tax effects resulting from the Tax Cuts and Jobs Act, from accumulated other comprehensive (loss) income to retained earnings. ASU No. 2018-02 is effective for interim and annual reporting periods beginning after December 15, 2018 and early adoption is permitted. The Company expects to adopt the provisions of ASU No. 2018-02 for the fiscal year beginning April 1, 2019. As the Company has not yet completed its final review of the impact of ASU No. 2018-02 but expects to by March 31, 2019, the Company has not determined whether the adoption of this guidance will have a material impact on its consolidated financial statements or disclosures. In March 2018, the FASB issued ASU No. 2018-05, " Income Taxes (Topic 740): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 ," ("ASU No. 2018-05"). ASU No. 2018-05 amends certain SEC material in Topic 740 for the income tax accounting implications of the Tax Cuts and Jobs Act. ASU No. 2018-05 was effective immediately. The Company evaluated the impact of the Tax Cuts and Jobs Act as well as the guidance of Staff Accounting Bulletin 118 ("SAB 118") and incorporated the changes into the determination of a reasonable estimate of deferred taxes and appropriate disclosures in the notes to the Company’s consolidated financial statements. The Company will continue to evaluate the impact this tax reform legislation may have on our results of operations, financial position, cash flows and related disclosures. In June 2018, the FASB issued ASU No. 2018-07, " Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting," ("ASU No. 2018-07") . ASU No. 2018-07 requires equity-classified share-based payment awards issued to nonemployees to be measured on the grant date, rather than remeasuring the awards through the performance completion date as previously required. Additionally, for nonemployee awards with performance conditions, compensation cost associated with the award is to be recognized when achievement of the performance condition is probable, rather than upon achievement of the performance condition. Further, the requirement to reassess the liability or equity classification for nonemployee awards upon vesting is eliminated, except for awards in the form of convertible instruments. ASU No. 2018-07 also clarifies that any share-based payment awards issued to customers should be evaluated under ASC 606, Revenue from Contracts with Customers . ASU No. 2018-07 is effective for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year, with early adoption permitted after the adoption of ASU No. 2014-09. The Company expects to adopt the provisions of ASU No. 2018-07 for the fiscal year beginning April 1, 2019. As the Company has not yet completed its final review of the impact of ASU No. 2018-07 but expects to by March 31, 2019, the Company has not determined whether the adoption of this guidance will have a material impact on its consolidated financial statements or disclosures. In August 2018, the FASB issued ASU No. 2018-13, " Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement" ("ASU No. 2018-13") . ASU No. 2018-13 removes, modifies, and adds certain recurring and nonrecurring fair value measurement disclosures, including removing disclosures around the amount(s) of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, the policy for timing of transfers between levels, and the valuation processes for Level 3 fair value measurements, among other things. ASU No. 2018-13 adds disclosure requirements around changes in unrealized gains and losses included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and a narrative description of measurement uncertainty. The amendments in ASU No. 2018-13 are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty are to be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption, with all other amendments applied retrospectively to all periods presented. Early adoption is permitted. The Company early adopted the provisions of ASU No. 2018-13 during the three months ended September 30, 2018, which did not have a material impact on its consolidated financial statements or disclosures because the Company does not currently have any Level 3 fair value measurements on a recurring or nonrecurring basis, and also has not had transfers between Level 1 and Level 2 of the fair value hierarchy.

License and Collaboration Agree

License and Collaboration Agreements	6 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
License and Collaboration Agreements	License and Collaboration Agreements Oxford BioMedica License Agreement On June 5, 2018, the Company, through its wholly owned subsidiary, ASG, entered into an exclusive license agreement (the "Oxford BioMedica Agreement") with Oxford BioMedica (UK) Ltd. ("Oxford BioMedica"), pursuant to which the Company received a worldwide, exclusive, royalty-bearing, sub-licensable license under certain patents and other intellectual property controlled by Oxford BioMedica to develop and commercialize AXO-Lenti-PD and related gene therapy products for all diseases and conditions. In June 2018, as consideration for the license, the Company made an upfront nonrefundable payment to Oxford BioMedica of $30.0 million , $5.0 million of which will be applied as a credit against the process development work and clinical supply that Oxford BioMedica will provide to the Company. Under the terms of the Oxford BioMedica Agreement, the Company could be obligated to make payments to Oxford BioMedica totaling up to $55.0 million upon the achievement of specified development milestones and $757.5 million upon the achievement of specified regulatory and sales milestones. The Company will also be obligated to pay Oxford BioMedica a tiered royalty from 7% to 10% , based on yearly aggregate net sales of the underlying gene therapy products, subject to specified reductions upon the occurrence of certain events as set forth in the Oxford BioMedica Agreement. These royalties are required to be paid, on a product-by-product and country-by-country basis, until the latest to occur of the expiration of the last to expire valid claim of a licensed patent covering such product in such country, the expiration of regulatory exclusivity for such product in such country, or 10 years after the first commercial sale of such product in such country. The Company is solely responsible, at its expense, for all activities related to the development and commercialization of the gene therapy products underlying the Oxford BioMedica Agreement. Pursuant to the Oxford BioMedica Agreement, the Company is required to use commercially reasonable efforts to develop, obtain regulatory approval of, and commercialize a gene therapy product underlying the Oxford BioMedica Agreement in the United States and at least one major market country in Europe. In addition, the Company is required to meet certain diligence milestones and to include at least one U.S.-based clinical trial site in a pivotal study of a gene therapy product underlying the Oxford BioMedica Agreement. If the Company fails to meet any of these specified development milestones, it may cure such failure by paying Oxford BioMedica certain fees, which range from $0.5 million to $1.0 million . The Company has evaluated the Oxford BioMedica Agreement and has determined that the acquired set of assets and activities did not meet the definition of a business and thus the transaction was not considered a business combination. The Company determined that the in-process research and development ("IPR&D") had not reached technological feasibility and therefore has no alternative future use. Accordingly, $25.0 million of the initial payment required under the license agreement was recorded as research and development expense in the Company's unaudited condensed consolidated statements of operations during the six months ended September 30, 2018. As the remaining $5.0 million of the initial payment under the licensing agreement represents a nonrefundable payment for process development work and clinical supply that Oxford BioMedica will provide over the term of the license agreement, the Company fully capitalized this portion of the payment upon execution, with $1.1 million remaining capitalized within prepaid expenses and other current assets and $3.7 million remaining capitalized within other non-current assets in its unaudited condensed consolidated balance sheet as of September 30, 2018, which will be recorded to research and development expense as the process development work and clinical supply are provided by Oxford BioMedica. Additionally, the Company incurred $1.2 million and $1.3 million of AXO-Lenti-PD program-specific costs in its unaudited condensed consolidated statements of operations during the three and six-months ended September 30, 2018, respectively. During the three and six-months ended September 30, 2018, the Company paid a total of $0.1 million and $30.1 million , respectively, to Oxford BioMedica, including the upfront nonrefundable payment during the six months ended September 30, 2018. Benitec Biopharma License and Collaboration Agreement On July 8, 2018, ASG entered into a license and collaboration agreement (the "Benitec Agreement") with Benitec Biopharma Limited ("Benitec"). Pursuant to the Benitec Agreement, the Company received a worldwide, exclusive, royalty-bearing, sub-licensable license under certain patents and other intellectual property controlled by Benitec to develop and commercialize investigational gene therapy AXO-AAV-OPMD and related gene therapy products (collectively, the "AXO-AAV-OPMD Program") for all diseases and conditions. Under the Benitec Agreement, the Company will also collaborate with Benitec on five additional research plans as part of the "Collaboration Programs" for other genetic neurological or neuromuscular disorders using Benitec technologies. The Company will receive a worldwide, exclusive, royalty-bearing, sub-licensable license under certain patents and other intellectual property controlled by Benitec to develop and commercialize products arising from each Collaboration Program. The Company has evaluated the Benitec Agreement and has determined that the acquired set of assets and activities did not meet the definition of a business and thus the transaction was not considered a business combination. The Company determined that the IPR&D had not reached technological feasibility and therefore has no alternative future use. Accordingly, the $10.0 million upfront nonrefundable payment required under the terms of the Benitec Agreement was recorded as research and development expense in the Company's unaudited condensed consolidated statements of operations during the three and six-months ended September 30, 2018. Additionally, the Company incurred $1.7 million of AXO-AAV-OPMD program-specific costs in its unaudited condensed consolidated statements of operations during the three and six-months ended September 30, 2018. During the three and six-months ended September 30, 2018, the Company paid a total of $10.0 million to Benitec, including the upfront nonrefundable payment. Further, the Company will be obligated to make payments to Benitec totaling up to (i) for the AXO-AAV-OPMD Program, $67.5 million upon the achievement of specified development and regulatory milestones and $120.0 million upon the achievement of specified sales milestones, and (ii) for each Collaboration Program, $33.5 million upon the achievement of specified development and regulatory milestones and $60.0 million upon the achievement of specified sales milestones. Benitec will receive 30% of net profits of world-wide sales of products from the AXO-AAV-OPMD Program, subject to an agreed minimum amount for such payments. This profit-sharing payment will be made for so long as the Company or its affiliates or sublicensees commercialize such products. The Company will also pay Benitec a tiered royalty based on yearly aggregate net sales of products arising from each Collaboration Program, subject to specified reductions upon the occurrence of certain events as set forth in the Benitec Agreement. These royalties are required to be paid, on a product-by-product and country-by-country basis, until the latest to occur of the expiration of the last to expire valid claim of a licensed patent covering such product in such country, the expiration of regulatory exclusivity for such product in such country, or ten years after the first commercial sale of such product in such country. Under the Benitec Agreement, Benitec will perform certain development and manufacturing activities for the AXO-AAV-OPMD Program and research activities for each Collaboration Program, and the Company will reimburse Benitec for its costs incurred, in accordance with an agreed-upon research and development plan and budget. The Company is solely responsible, at its expense, for all other activities related to the research, development and commercialization of products from the AXO-AAV-OPMD Program and the Collaboration Programs.

Accrued Expenses

Accrued Expenses	6 Months Ended
	Sep. 30, 2018
Payables and Accruals [Abstract]
Accrued Expenses	Accrued Expenses As of September 30, 2018 , and March 31, 2018 , the Company’s accrued expenses consisted of the following (in thousands): September 30, 2018 March 31, 2018 Research and development expenses $ 18,409 $ 21,855 Salaries, bonuses, and other compensation expenses 3,169 7,718 Legal expenses 1,073 779 Other expenses 1,664 1,510 Total accrued expenses $ 24,315 $ 31,862

Long Term Debt

Long Term Debt	6 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Long Term Debt	Long-term Debt On February 2, 2017, the Company and its subsidiaries, AHL, ASG and ASI, entered into a loan and security agreement (as amended on May 24 and September 22, 2017) (the "Loan Agreement") with Hercules Capital, Inc., ("Hercules"), under which the Company, AHL and ASG (the "Borrowers") borrowed an aggregate of $55.0 million (the "Term Loan"). Subsequently, the Company added its subsidiary ASA as a Borrower in July 2017 and its subsidiaries ATH and ATI as Borrowers in April 2018. Pursuant to the Loan Agreement, ASI has issued a guaranty of the Borrowers’ obligations under the Loan Agreement. The Term Loan bears interest at a variable per annum rate calculated for any day as the greater of either (i) the prime rate plus 6.80% , and (ii) 10.55% . The Term Loan has a scheduled maturity date of March 1, 2021. The Borrowers were obligated to make monthly payments of accrued interest under the Loan Agreement until September 1, 2018, followed by monthly installments of principal and interest beginning October 1, 2018 through March 1, 2021. In connection with the Loan Agreement, the Borrowers and ASI, as guarantor, granted Hercules a first position lien on substantially all of their respective assets, excluding intellectual property. Prepayment of the Term Loan is subject to penalty. On May 24, 2017, the Loan Agreement was amended such that, commencing July 1, 2017, the required minimum amount of unrestricted cash is equal to the lesser of (i) $35.0 million (the "Applicable Amount") plus certain aged accounts payable amounts (as further defined in the Loan Agreement) and (ii) the outstanding amount of debt under the Loan Agreement plus certain aged accounts payable (as further defined in the Loan Agreement), provided that the Applicable Amount may be lowered to $30 million upon the achievement of certain clinical milestones as set forth in the Loan Agreement. The Loan Agreement also includes customary events of default. Upon the occurrence of an event of default, a default interest rate of an additional 5.0% may be applied to the outstanding principal balance, and Hercules may declare all outstanding obligations immediately due and payable and take such other actions as set forth in the Loan Agreement. At no time has the Company been in default under the provisions of the Loan Agreement. In addition, for so long as the Term Loan remains outstanding, the Company shall be required to use its commercially reasonable efforts to afford Hercules the opportunity to participate in future underwritten equity offerings of the Company’s common shares up to a total of $3.0 million . In connection with the Loan Agreement, the Company issued a warrant to Hercules, exercisable for an aggregate of 274,086 of the Company’s common shares at an exercise price of $12.04 per share (the "Warrant"). In August 2017, Hercules exercised the Warrant on a cashless basis and received a net issuance of 129,827 of the Company's common shares. The Company has accounted for the Warrant as an equity instrument since it was indexed to the Company’s common shares and met the criteria for classification in shareholders’ equity. The relative fair value of the Warrant on the date of issuance was approximately $2.3 million and was treated as a discount to the debt. This amount will be amortized to interest expense under the effective interest method over the life of the Term Loan, which is a period of 48 months. The Company estimated the value of the Warrant using the Black-Scholes model. The key assumptions used to value the Warrant were as follows: Exercise price $ 12.04 Share price on date of issuance $ 11.96 Volatility 77.6 % Risk-free interest rate 2.27 % Expected dividend yield — % Contractual term (in years) 7 In addition, at the closing of the Term Loan, the Company paid transaction costs of $1.5 million , which were recorded as a discount on the debt and will be amortized to interest expense using the effective interest method over the life of the Term Loan, which is a period of 48 months. Outstanding debt obligations are as follows (in thousands): September 30, 2018 March 31, 2018 Principal amount $ 55,000 $ 55,000 Less: unamortized discount and debt issuance costs (1,682 ) (2,322 ) Loan payable less unamortized discount and debt issuance costs 53,318 52,678 Less: current portion of long-term debt (20,009 ) (9,753 ) Long-term loan payable, net of current maturities $ 33,309 $ 42,925

Related Party Transactions

Related Party Transactions	6 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions (A) Services Agreements: In 2015, the Company and ASI entered into a services agreement with RSI (the "Services Agreement") under which RSI has agreed to provide certain administrative and research and development services to the Company. The Company and ASI amended and restated the Services Agreement with RSI on October 13, 2015 effective for the fiscal year commencing April 1, 2015. Under the Services Agreement, as amended and restated, the Company pays or reimburses RSI for any expenses it, or third parties acting on its behalf, incurs for the Company. For any general and administrative and research and development activities performed by RSI employees, RSI charges back the employee compensation expense plus a predetermined mark-up. Employee compensation expense, inclusive of base salary and fringe benefits, is determined based upon the relative percentage of time utilized on Company matters. All other costs are billed back at cost. The accompanying interim unaudited condensed consolidated financial statements include third-party expenses that have been paid by RSI and RSL, as well as share-based compensation expense allocated to the Company by RSL (see Note 8(B)(2)). In February 2017, the Company and ASI amended and restated the Services Agreement, effective as of December 13, 2016, to add ASG as a services recipient. In addition, in February 2017, ASG entered into a separate services agreement with RSG, effective as of December 13, 2016, for the provision of services by RSG to ASG in relation to the identification of potential product candidates and project management of clinical trials, as well as other services related to development, administrative and financial activities. Under the Services Agreements, the Company incurred expenses of $0.9 million and $1.6 million for the three months ended September 30, 2018 and 2017, respectively, and $4.3 million and $4.4 million for the six months ended September 30, 2018 and 2017, respectively, inclusive of the predetermined mark-up. (B) Family Relationships: Geetha Ramaswamy, MD, the former Vice President, Medical and Scientific Strategy of ASI and an employee of RSI, is the mother of Vivek Ramaswamy, the Chief Executive Officer of RSI, former Chairman of the Company's Board of Directors and former Chief Executive Officer of the Company. Sarah Friedhoff, formerly Senior Business Operations and Research and Development Specialist of ASI, is the daughter of Lawrence Friedhoff, MD, PhD, formerly the Chief Development Officer of ASI and an officer of RSI. Shankar Ramaswamy, MD, the Senior Vice President, Business Development of ASI, and a former employee of RSI, is the brother of Vivek Ramaswamy. Lawrence Friedhoff, MD, PhD, Geetha Ramaswamy, MD and Sarah Friedhoff were no longer employed by ASI beginning in October 2017. The accompanying interim unaudited condensed consolidated financial statements include share-based compensation expense associated with family members Geetha Ramaswamy, MD, Shankar Ramaswamy, MD and Sarah Friedhoff (see Note 8(B)(3)). Salary expenses for Shankar Ramaswamy, MD were $75,000 and $66,950 for the three months ended September 30, 2018 and 2017, respectively and $150,000 and $133,900 for the six months ended September 30, 2018 and 2017, respectively. Salary expenses for Geetha Ramaswamy, MD were $ 66,950 and $133,900 for the three and six-months ended September 30, 2017 , respectively. Salary expenses for Sarah Friedhoff were $19,312 and $38,625 for the three and six-months ended September 30, 2017 , respectively. (C) RSL Private Placement Financing: On July 9, 2018, the Company received $25.0 million of net proceeds from RSL in exchange for the issuance and sale of 14,285,714 of the Company's common shares to RSL at a purchase price of $1.75 per common share, which was the closing price per share of the Company's common shares on the Nasdaq Global Select Market on June 5, 2018, the date of the share purchase agreement (see Note 7).

Shareholders' Equity

Shareholders' Equity	6 Months Ended
	Sep. 30, 2018
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders' Equity In April 2017, the Company issued and sold 7,753,505 common shares, including 1,011,326 common shares sold pursuant to the exercise in full of the underwriters’ option to purchase additional shares, at an offering price of $18.54 per common share for gross proceeds of $143.7 million . The net proceeds to the Company were $134.5 million , after deducting underwriting discounts and commissions and offering expenses paid by the Company. During the three months ended March 31, 2018 and September 30, 2018, RSL incurred $0.3 million and RSI incurred $ 0.4 million , respectively, of expenses on behalf of the Company. These amounts were treated as capital contributions. On June 5, 2018, the Company entered into a share purchase agreement with RSL, its majority shareholder, pursuant to which the Company agreed to issue and sell to RSL 14,285,714 of its common shares at a purchase price of $ 1.75 per share, which was the closing price per share of the Company's common shares on the Nasdaq Global Select Market on June 5, 2018. On July 9, 2018, the Company received $25.0 million of net proceeds from RSL upon the closing of this private placement (see Note 6 (C)). On June 22, 2018, the Company entered into a sales agreement with Cowen and Company, LLC ("Cowen") to sell the Company's common shares having an aggregate offering price of up to $75.0 million from time to time through an at-the-market equity offering program under which Cowen is acting as the Company's agent. Cowen is entitled to compensation for its services in an amount up to 3% of the gross proceeds of any of the Company's common shares sold under the sales agreement. As of September 30, 2018, approximately $75.0 million of the Company's common shares remained available for sale under the sales agreement.

Share-Based Compensation

Share-Based Compensation	6 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-Based Compensation In April 2017, the number of common shares authorized for issuance under the Company's 2015 Equity Incentive Plan increased automatically to an aggregate of approximately 16.5 million common shares in accordance with the terms of the 2015 Equity Incentive Plan. In June 2017, the Company's Board of Directors amended and restated the 2015 Equity Incentive Plan (the "2015 Plan") to, among other things, increase the number of common shares authorized for issuance thereunder to approximately 20.5 million common shares. The 2015 Plan became effective upon shareholder approval in August 2017. In April 2018, the number of common shares authorized for issuance under the 2015 Plan increased automatically to approximately 24.8 million common shares in accordance with the terms of the 2015 Plan. At September 30, 2018 , a total of 8.2 million common shares were available for future grant under the 2015 Plan, and options to purchase approximately 15.8 million common shares were outstanding under the 2015 Plan, with a weighted average exercise price of $4.66 per share. (A) Stock Options Granted to Employees and Directors: During the six months ended September 30, 2018 and 2017 , the Company granted options to its employees and directors under the 2015 Plan to purchase a total of 2.1 million and 8.8 million common shares, respectively. The stock options granted during the six months ended September 30, 2018 include approximately 0.6 million common shares with market-based performance conditions to employees with a weighted average exercise price of $2.98 per share, a contractual term of 10 years, and a corresponding estimated grant date fair value of $1.1 million . As of September 30, 2018 , stock options with market-based performance conditions to purchase 1.5 million common shares were outstanding with a weighted-average exercise price of $2.02 per share. The market-based performance options vest based on exceeding certain closing prices of the Company's common shares. As of September 30, 2018 , stock options with market-based performance conditions to purchase approximately 0.4 million common shares with a weighted-average exercise price of $1.46 per share were vested, which occurred during the six months ended September 30, 2018 . The Company recorded total share-based compensation expense related to stock options issued to Company employees and directors of $5.2 million and $12.7 million , respectively, for the three months ended September 30, 2018 and 2017, and $9.8 million and $24.9 million for the six months ended September 30, 2018 and 2017. At September 30, 2018 , total unrecognized compensation expense related to non-vested options was $27.8 million , which is expected to be recognized over the remaining weighted-average service period of 2.3 years . (B) Share-Based Compensation for Related Parties: (1) Stock Options Granted to Non-Employees: During the six months ended September 30, 2018 and 2017 , the Company granted options to purchase a total of 1.0 million and 0.2 million common shares, respectively, to consultants as well as employees and consultants of RSI as compensation for support services provided to the Company. The fair value of the stock options granted to RSI employees and other consultants is accounted for by the Company in accordance with the authoritative guidance for non-employee equity awards and is remeasured on each valuation date until performance is complete using the Black-Scholes pricing model. Each award is subject to a specified vesting schedule. Compensation expense will be recognized by the Company over the required service period to earn each award. The Company recorded $(23) thousand and $0.3 million of share-based compensation expense (benefit) for the three months ended September 30, 2018 and 2017, respectively, and $0.4 million and $1.3 million for the six months ended September 30, 2018 and 2017, respectively. The share-based compensation expense (benefit) was recorded within research and development and general and administrative expenses in the accompanying unaudited condensed consolidated statements of operations. The total remaining unrecognized compensation cost related to the non-vested stock options amounted to $1.2 million as of September 30, 2018 , which is expected to be recognized over the remaining weighted-average service period of 2.3 years . (2) Share-Based Compensation Allocated to the Company by RSL: The Company incurs share-based compensation expense for RSL common share awards and RSL options issued by RSL to RSL, RSG and RSI employees. Share-based compensation expense is allocated to the Company by RSL based upon the relative percentage of time utilized by RSL, RSG and RSI employees on Company matters. The RSL common share awards are fair valued on the date of grant and that fair value is recognized over the requisite service period. Significant judgment and estimates were used to estimate the fair value of these awards, as they are not publicly traded. RSL common share awards are subject to specified vesting schedules and requirements (a mix of time-based, performance-based and corporate event-based, including targets for RSL’s post-IPO market capitalization and future financing events). The Company estimated the fair value of each RSL option on the date of grant using the Black-Scholes closed-form option-pricing model. The Company recorded share-based compensation expense (benefit) of $(3.2) million and $2.3 million for the three months ended September 30, 2018 and 2017 , respectively, and $(2.7) million and $4.4 million for the six months ended September 30, 2018 and 2017 , respectively, in relation to the RSL common share awards and options issued by RSL to RSG and RSI employees, net of forfeitures. (3) Share-Based Compensation for Family Members: The Company recorded aggregate share-based compensation expense of $0.9 million and $1.0 million for the three months ended September 30, 2018 and 2017 , respectively, and $1.7 million and $2.4 million for the six months ended September 30, 2018 and 2017, respectively, in connection with options vesting for Geetha Ramaswamy, MD, Shankar Ramaswamy, MD and Sarah Friedhoff. Shankar Ramaswamy, MD, while previously employed by RSI, was also granted RSL common shares. The Company recorded share-based compensation expense of $7 thousand and $0.1 million for the three months ended September 30, 2018 and 2017, respectively, and $0.1 million and $0.2 million for the six months ended September 30, 2018 and 2017, respectively, related to the RSL common share awards held by Shankar Ramaswamy, which the Company has recorded as research and development expense in the accompanying unaudited condensed consolidated statements of operations. At September 30, 2018 , all compensation expense related to these RSL common share awards had been recognized.

Restructuring

Restructuring	6 Months Ended
	Sep. 30, 2018
Restructuring and Related Activities [Abstract]
Restructuring	Restructuring In October 2017, the Company initiated and committed to the first of two corporate realignments to focus its efforts and resources on the Company's ongoing and future programs that included a reduction in its workforce and a transfer of certain employees to affiliates. The second realignment was initiated and committed to in February 2018. The Company completed the reduction in headcount from these actions in the fourth quarter of fiscal 2018. During the six months ended September 30, 2018 , the Company made cash expenditures of approximately $1.6 million for one-time severance and related costs in connection with the corporate realignments completed in the prior fiscal year. The impacted employees are eligible to receive severance payments in specified amounts, health benefits and outplacement services. The Company has recorded these charges in research and development and general and administrative expenses in the accompanying condensed consolidated statements of operations based on responsibilities of the impacted employees. The following sets forth information regarding the balances and activity associated with the Company's accrued employee severance and other personnel benefits (in thousands): Balance as of March 31, 2018 Expenses, net Cash Non-cash Balance as of September 30, 2018 Employee severance and other personnel benefits $ 2,460 $ — $ (1,573 ) $ — $ 887

Income Taxes

Income Taxes	6 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company is not subject to taxation under the laws of Bermuda since it was organized as a Bermuda Exempted Limited Company, for which there is no current tax regime. The Company’s provision for income taxes is primarily federal, state and local income taxes in the United States. The Company assesses the realizability of its deferred tax assets at each balance sheet date based on available positive and negative evidence in order to determine the amount which is more likely than not to be realized and records a valuation allowance as necessary. The Company's effective tax rates of (0.3)% and 2.2% for the three months ended September 30, 2018 and 2017, respectively, and (0.2)% and (0.7)% for the six months ended September 30, 2018 and 2017, respectively, differ from the Bermuda federal statutory rate of 0% primarily due to the U.S. permanent unfavorable tax differences, stock compensation deductions and a valuation allowance that effectively eliminates the Company's net deferred tax assets. On December 22, 2017, the President of the United States signed into law an Act to provide for reconciliation pursuant to Titles II and V of the concurrent resolution on the budget for fiscal year 2018 (commonly known as the "Tax Cuts and Jobs Act"), which introduced a comprehensive set of tax reforms. The Tax Cuts and Jobs Act significantly revises U.S. tax law by, among other provisions, lowering the U.S. federal statutory income tax rate from 35% to 21% and eliminating or reducing certain income tax deductions. The effects of changes in tax laws are required to be recognized in the period in which the legislation is enacted. However, due to the complexity and significance of the Tax Cuts and Jobs Act’s provisions, the SEC staff issued SAB 118, which allows companies to record the tax effects of the Tax Cuts and Jobs Act on a provisional basis based on a reasonable estimate, and then, if necessary, subsequently adjust such amounts during a limited measurement period as more information becomes available. The measurement period ends when a company has obtained, prepared, and analyzed the information necessary to finalize its accounting, but cannot extend beyond one year from enactment. The Tax Cuts and Jobs Act did not have a material impact on our financial statements since our deferred temporary differences are fully offset by a valuation allowance and the Company does not have any offshore earnings from which to record the mandatory transition tax. However, given the significant complexity of the Tax Cuts and Jobs Act, anticipated guidance from the U.S. Treasury about implementing the Tax Cuts and Jobs Act, and the potential for additional guidance from the SEC or the FASB related to the Tax Cuts and Jobs Act, these estimates may be adjusted during the measurement period. The Company's provisional amounts for income taxes were based on the Company’s present interpretations of the Tax Cuts and Jobs Act and current available information, including assumptions and expectations about future events, such as its projected financial performance, and are subject to further refinement as additional information becomes available (including potential new or interpretative guidance issued by the FASB or the Internal Revenue Service and other tax agencies) and further analyses are completed. The Company continues to analyze the changes in certain income tax deductions and gather additional data to compute the full impacts on the Company’s deferred and current tax assets and liabilities.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies As of September 30, 2018, the Company had entered into commitments under a license agreement with Oxford BioMedica, a license and collaboration agreement with Benitec, a development, marketing, and supply agreement with Arena Pharmaceuticals GmbH ("Arena"), a Loan Agreement with Hercules, an amended services agreement with RSI, a separate service agreement with RSG (see Note 6(A)). In addition, the Company has entered into services agreements with third parties for pharmaceutical manufacturing and research activities. Expenditures to contract research organizations and contract manufacturing organizations represent significant costs in clinical development. Subject to required notice periods and the Company's obligations under binding purchase orders, the Company can elect to discontinue the work under these agreements at any time. The Company expects to enter into other commitments as the business further develops. During the six months ended September 30, 2018 , there were no material changes outside the ordinary course of business to the Company's specified contractual obligations set forth in the contractual obligations table included in the Annual Report, other than to the license agreement for 19,554 square feet of office space in New York, New York, which was originally set to expire in January 2019 and was extended to January 2021. For the three and six-months ended September 30, 2018, the Company incurred $0.4 million and $0.9 million , respectively, in rent expense associated with all contractual rent obligations. The following table provides information regarding remaining contractual rent obligations due within each respective year ending March 31, as of September 30, 2018 (in thousands): Total 2019 2020 2021 Rent obligations, net of prepayments $ 3,576 $ 895 $ 1,791 $ 890

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation: The Company’s fiscal year ends on March 31, and its fiscal quarters end on June 30, September 30 and December 31. The accompanying interim unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States ("U.S. GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and disclosures required by U.S. GAAP for complete financial statements. These interim unaudited condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended March 31, 2018 the ("Annual Report"), filed with the Securities and Exchange Commission ("SEC") on June 11, 2018. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary to present fairly the financial position of the Company and its results of operations and cash flows for the interim periods presented have been included. Operating results for the three and six-months ended September 30, 2018 are not necessarily indicative of the results that may be expected for the year ending March 31, 2019, for any other interim period, or for any other future year. Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification ("ASC") and Accounting Standards Update ("ASU") issued by the Financial Accounting Standards Board ("FASB"). The unaudited condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. The Company has no unconsolidated subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. There have been no significant changes in the Company’s accounting policies from those disclosed in its Annual Report.
Use of Estimates	Use of Estimates: The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company regularly evaluates estimates and assumptions related to the assets, liabilities, costs and expenses (including compensation expense) allocated to the Company under its services agreements with Roivant Sciences, Inc. ("RSI") and Roivant Sciences GmbH ("RSG"), each a wholly owned subsidiary of the Company’s parent company, RSL, as well as the evaluation of the Company's ability to continue as a going concern, contingent liabilities, share-based compensation and research and development costs. Specifically, the Company estimates the grant date fair value of stock option awards with only time-based vesting requirements using a Black-Scholes valuation model and uses a Monte Carlo Simulation method under the income approach to estimate the grant date fair value of stock option awards with market-based performance conditions. The Company bases its estimates and assumptions on historical experience and on various other factors that it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates.
Net Loss per Common Share	Net Loss per Common Share: Basic net loss per common share is computed by dividing the net loss applicable to common shareholders by the weighted-average number of common shares outstanding during the period. Diluted net loss per common share is computed by dividing the net loss applicable to common shareholders by the diluted weighted-average number of common shares outstanding during the period calculated in accordance with the treasury stock method.
Financial Instruments	Fair Value Measurements: The Company utilizes fair value measurement guidance prescribed by accounting standards to value its financial instruments. The guidance establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company’s own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. Fair value is defined as the exchange price, or exit price, representing the amount that would be received from the sale of an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, the guidance establishes a three-tier fair value hierarchy that distinguishes among the following: • Level 1-Valuations are based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access. • Level 2-Valuations are based on quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active and models for which all significant inputs are observable, either directly or indirectly. • Level 3-Valuations are based on inputs that are unobservable (supported by little or no market activity) and significant to the overall fair value measurement. To the extent the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The Company’s financial instruments include cash, accounts payable and long-term debt. Cash and accounts payable are stated at their respective historical carrying amounts, which approximate fair value due to their short-term nature.
Recent Accounting Pronouncements	Recent Accounting Pronouncements: In February 2016, the FASB issued ASU No. 2016-02, " Leases (Topic 842) " ("ASU No. 2016-02"), as well as ASU No. 2018-10, " Codification Improvements to Topic 842, Leases " and ASU No. 2018-11, " Leases (Topic 842): Targeted Improvements " in July 2018 (collectively, the "Lease Standards"), which relate to a comprehensive new lease standard that amends various aspects of existing accounting guidance for leases. The core principle of the Lease Standards will require lessees to present the assets and liabilities that arise from leases on their balance sheets. The Lease Standards are effective for annual periods beginning after December 15, 2018, and interim periods within fiscal years beginning after December 15, 2018. Early adoption is permitted. The Company has implemented a process to identify its outstanding lease portfolio and is currently evaluating its outstanding leases to determine the impact the Lease Standards will have on its consolidated financial statements. In January 2017, the FASB issued ASU 2017-01, " Business Combinations (Topic 805): Clarifying the Definition of a Business " ("ASU No. 2017-01"), which clarifies the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The Company adopted the provisions of ASU No. 2017-01 on April 1, 2018 on a prospective basis. The impact on the Company's consolidated financial statements and disclosures will depend on the facts and circumstances of any specific future transactions. See Note 3 for further information regarding the impact of the adoption of ASU No. 2017-01 on the license agreements executed during the three and six-months ended September 30, 2018. In February 2018, the FASB issued ASU No. 2018-02, " Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income" ("ASU No. 2018-02"). ASU No. 2018-02 allows companies to reclassify stranded tax effects resulting from the Tax Cuts and Jobs Act, from accumulated other comprehensive (loss) income to retained earnings. ASU No. 2018-02 is effective for interim and annual reporting periods beginning after December 15, 2018 and early adoption is permitted. The Company expects to adopt the provisions of ASU No. 2018-02 for the fiscal year beginning April 1, 2019. As the Company has not yet completed its final review of the impact of ASU No. 2018-02 but expects to by March 31, 2019, the Company has not determined whether the adoption of this guidance will have a material impact on its consolidated financial statements or disclosures. In March 2018, the FASB issued ASU No. 2018-05, " Income Taxes (Topic 740): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 ," ("ASU No. 2018-05"). ASU No. 2018-05 amends certain SEC material in Topic 740 for the income tax accounting implications of the Tax Cuts and Jobs Act. ASU No. 2018-05 was effective immediately. The Company evaluated the impact of the Tax Cuts and Jobs Act as well as the guidance of Staff Accounting Bulletin 118 ("SAB 118") and incorporated the changes into the determination of a reasonable estimate of deferred taxes and appropriate disclosures in the notes to the Company’s consolidated financial statements. The Company will continue to evaluate the impact this tax reform legislation may have on our results of operations, financial position, cash flows and related disclosures. In June 2018, the FASB issued ASU No. 2018-07, " Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting," ("ASU No. 2018-07") . ASU No. 2018-07 requires equity-classified share-based payment awards issued to nonemployees to be measured on the grant date, rather than remeasuring the awards through the performance completion date as previously required. Additionally, for nonemployee awards with performance conditions, compensation cost associated with the award is to be recognized when achievement of the performance condition is probable, rather than upon achievement of the performance condition. Further, the requirement to reassess the liability or equity classification for nonemployee awards upon vesting is eliminated, except for awards in the form of convertible instruments. ASU No. 2018-07 also clarifies that any share-based payment awards issued to customers should be evaluated under ASC 606, Revenue from Contracts with Customers . ASU No. 2018-07 is effective for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year, with early adoption permitted after the adoption of ASU No. 2014-09. The Company expects to adopt the provisions of ASU No. 2018-07 for the fiscal year beginning April 1, 2019. As the Company has not yet completed its final review of the impact of ASU No. 2018-07 but expects to by March 31, 2019, the Company has not determined whether the adoption of this guidance will have a material impact on its consolidated financial statements or disclosures. In August 2018, the FASB issued ASU No. 2018-13, " Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement" ("ASU No. 2018-13") . ASU No. 2018-13 removes, modifies, and adds certain recurring and nonrecurring fair value measurement disclosures, including removing disclosures around the amount(s) of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, the policy for timing of transfers between levels, and the valuation processes for Level 3 fair value measurements, among other things. ASU No. 2018-13 adds disclosure requirements around changes in unrealized gains and losses included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and a narrative description of measurement uncertainty. The amendments in ASU No. 2018-13 are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty are to be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption, with all other amendments applied retrospectively to all periods presented. Early adoption is permitted. The Company early adopted the provisions of ASU No. 2018-13 during the three months ended September 30, 2018, which did not have a material impact on its consolidated financial statements or disclosures because the Company does not currently have any Level 3 fair value measurements on a recurring or nonrecurring basis, and also has not had transfers between Level 1 and Level 2 of the fair value hierarchy.

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Sep. 30, 2018
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	As of September 30, 2018 , and March 31, 2018 , the Company’s accrued expenses consisted of the following (in thousands): September 30, 2018 March 31, 2018 Research and development expenses $ 18,409 $ 21,855 Salaries, bonuses, and other compensation expenses 3,169 7,718 Legal expenses 1,073 779 Other expenses 1,664 1,510 Total accrued expenses $ 24,315 $ 31,862

Long Term Debt (Tables)

Long Term Debt (Tables)	6 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Key Assumptions Used to Value Warrants	The key assumptions used to value the Warrant were as follows: Exercise price $ 12.04 Share price on date of issuance $ 11.96 Volatility 77.6 % Risk-free interest rate 2.27 % Expected dividend yield — % Contractual term (in years) 7
Outstanding Debt Obligations	Outstanding debt obligations are as follows (in thousands): September 30, 2018 March 31, 2018 Principal amount $ 55,000 $ 55,000 Less: unamortized discount and debt issuance costs (1,682 ) (2,322 ) Loan payable less unamortized discount and debt issuance costs 53,318 52,678 Less: current portion of long-term debt (20,009 ) (9,753 ) Long-term loan payable, net of current maturities $ 33,309 $ 42,925

Restructuring (Tables)

Restructuring (Tables)	6 Months Ended
	Sep. 30, 2018
Restructuring and Related Activities [Abstract]
Schedule of Restructuring	The following sets forth information regarding the balances and activity associated with the Company's accrued employee severance and other personnel benefits (in thousands): Balance as of March 31, 2018 Expenses, net Cash Non-cash Balance as of September 30, 2018 Employee severance and other personnel benefits $ 2,460 $ — $ (1,573 ) $ — $ 887

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of Remaining Contractual Rent Obligations	The following table provides information regarding remaining contractual rent obligations due within each respective year ending March 31, as of September 30, 2018 (in thousands): Total 2019 2020 2021 Rent obligations, net of prepayments $ 3,576 $ 895 $ 1,791 $ 890

Description of Business (Detail

Description of Business (Details)	6 Months Ended
	Sep. 30, 2018subsidiarysegment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of subsidiaries | subsidiary	6
Number of operating segments	1
Number of reporting segments	1

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Fair Value, Inputs, Level 2
Net Loss per Common Share
Long-term debt	$ 53.3		$ 53.3
Stock Options
Net Loss per Common Share
Anti-dilutive securities not included in calculation of common shares outstanding (in shares)	15.8		15.8
Stock Options and Warrants
Net Loss per Common Share
Anti-dilutive securities not included in calculation of common shares outstanding (in shares)		5.4		10.4

License and Collaboration Agr_2

License and Collaboration Agreements (Details) - USD ($)	Jul. 08, 2018	Jun. 05, 2018	Sep. 30, 2018	Sep. 30, 2018	Mar. 31, 2018
License Agreement [Line Items]
Capitalized costs, current			$ 18,409,000	$ 18,409,000	$ 21,855,000
Oxford BioMedica (UK) Ltd.
License Agreement [Line Items]
Payments for license agreement		$ 30,000,000	100,000	30,100,000
License agreement costs			1,200,000	1,300,000
Payments for license agreement, developmental milestones		55,000,000
Payments for license agreement, regulatory and sales milestones		$ 757,500,000
License agreement term		10 years
Benitec Biopharma Limited
License Agreement [Line Items]
Payments for license agreement			10,000,000	10,000,000
License agreement costs			1,700,000	1,700,000
License agreement term	10 years
Payments for license and collaboration agreement, development and regulatory milestones, total	$ 67,500,000
Payments for license and collaboration agreement, sales milestones, total	120,000,000
Payments for license and collaboration agreement, development and regulatory milestones	33,500,000
Payments for license and collaboration agreement, sales milestones	$ 60,000,000
Percentage of profits to be received by Benitec	30.00%
Research and development expenses | Oxford BioMedica (UK) Ltd.
License Agreement [Line Items]
Payments for license agreement		$ 25,000,000
Prepaid Expenses and Other Current Assets and Other Noncurrent Assets | Oxford BioMedica (UK) Ltd.
License Agreement [Line Items]
Payments for license agreement		$ 5,000,000
Prepaid Expenses and Other Current Assets | Oxford BioMedica (UK) Ltd.
License Agreement [Line Items]
Capitalized costs, current			1,100,000	1,100,000
Other Noncurrent Assets | Oxford BioMedica (UK) Ltd.
License Agreement [Line Items]
Capitalized costs, noncurrent			$ 3,700,000	$ 3,700,000
Minimum | Oxford BioMedica (UK) Ltd.
License Agreement [Line Items]
Royalty percentage		7.00%
Fee if developmental milestones are not me		$ 500,000
Maximum | Oxford BioMedica (UK) Ltd.
License Agreement [Line Items]
Royalty percentage		10.00%
Fee if developmental milestones are not me		$ 1,000,000

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Mar. 31, 2018
Payables and Accruals [Abstract]
Research and development expenses	$ 18,409	$ 21,855
Salaries, bonuses, and other compensation expenses	3,169	7,718
Legal expenses	1,073	779
Other expenses	1,664	1,510
Total accrued expenses	$ 24,315	$ 31,862

Long Term Debt (Details)

Long Term Debt (Details) - USD ($)	Feb. 02, 2017	Aug. 31, 2017	May 24, 2017
Debt Instrument [Line Items]
Exercise of warrants (in shares)		129,827
Common Shares
Debt Instrument [Line Items]
Number of securities called by warrants (in shares)	274,086
Exercise price (in dollars per share)	$ 12.04
Fair value of warrants not settable in cash	$ 2,300,000
Loan and Security Agreement with Hercules Capital, Inc. | Secured Debt
Debt Instrument [Line Items]
Face amount	$ 55,000,000
Minimum unrestricted cash			$ 35,000,000
Minimum unrestricted cash if clinical milestone thresholds are met			$ 30,000,000
Default interest rate	5.00%
Maximum equity offering opportunity to be provided	$ 3,000,000
Loan term	48 months
Payments of loan facility costs	$ 1,500,000
Loan and Security Agreement with Hercules Capital, Inc. | Secured Debt | Minimum
Debt Instrument [Line Items]
Stated interest rate	10.55%
Loan and Security Agreement with Hercules Capital, Inc. | Secured Debt | Prime Rate
Debt Instrument [Line Items]
Variable interest rate	6.80%

Long Term Debt - Valuation Assu

Long Term Debt - Valuation Assumptions (Details) - Common Shares	Feb. 02, 2017year$ / shares
Class of Warrant or Right [Line Items]
Exercise price (in dollars per share)	$ 12.04
Share price on date of issuance (in dollars per share)	$ 11.96
Volatility
Class of Warrant or Right [Line Items]
Measurement input	0.776
Risk-free interest rate
Class of Warrant or Right [Line Items]
Measurement input	0.0227
Expected dividend yield
Class of Warrant or Right [Line Items]
Measurement input	0
Contractual term (in years)
Class of Warrant or Right [Line Items]
Measurement input | year	7

Long Term Debt - Outstanding De

Long Term Debt - Outstanding Debt Obligations (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Mar. 31, 2018
Debt Disclosure [Abstract]
Principal amount	$ 55,000	$ 55,000
Less: unamortized discount and debt issuance costs	(1,682)	(2,322)
Loan payable less unamortized discount and debt issuance costs	53,318	52,678
Less: current portion of long-term debt	(20,009)	(9,753)
Long-term loan payable, net of current maturities	$ 33,309	$ 42,925

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($)	Jul. 09, 2018	Jun. 05, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
RSI
Related Party Transaction [Line Items]
Expense under service agreement			$ 900,000	$ 1,600,000	$ 4,300,000	$ 4,400,000
Shankar Ramaswamy
Related Party Transaction [Line Items]
Officers' salary expense			$ 75,000	66,950	$ 150,000	133,900
Geetha Ramaswamy
Related Party Transaction [Line Items]
Officers' salary expense				66,950		133,900
Sarah Friedhoff
Related Party Transaction [Line Items]
Salary expense				$ 19,312		$ 38,625
Private Placement | RSL
Related Party Transaction [Line Items]
Net proceeds from common stock issued	$ 25,000,000
Shares sold in common stock issuance (in shares)	14,285,714	14,285,714
Price of shares sold in common stock issuance (in USD per share)	$ 1.75	$ 1.75

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 09, 2018	Jun. 05, 2018	Apr. 30, 2017	Sep. 30, 2018	Mar. 31, 2018	Jun. 22, 2018
Stock Offering
Shareholders' Equity
Sale of common stock in IPO (in shares)			7,753,505
Price per share (in dollars per share)			$ 18.54
Gross proceeds from common stock issued			$ 143.7
Net proceeds from common stock issued			$ 134.5
Underwriter's Option
Shareholders' Equity
Sale of common stock in IPO (in shares)			1,011,326
RSL
Shareholders' Equity
Capital contribution				$ 0.3	$ 0.3
RSI
Shareholders' Equity
Capital contribution				0.4	$ 0.4
RSL | Private Placement
Shareholders' Equity
Net proceeds from common stock issued	$ 25
Shares sold in common stock issuance (in shares)	14,285,714	14,285,714
Price of shares sold in common stock issuance (in USD per share)	$ 1.75	$ 1.75
Cowen and Company, LLC | Private Placement
Shareholders' Equity
Maximum offering under equity offering program						$ 75
Percentage of gross proceeds from common stock issuance paid for services						3.00%
Amount available for issuance under equity offering program				$ 75

Share-Based Compensation (Detai

Share-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Apr. 30, 2018	Jun. 30, 2017	Apr. 30, 2017
RSL
Share-Based Compensation
Share-based compensation expense	$ (3,200)	$ 2,300	$ (2,700)	$ 4,400
Stock Options
Share-Based Compensation
Total unrecognized compensation expense, stock options	27,800		$ 27,800
Remaining weighted-average service period			2 years 3 months 18 days
Stock Options | Grants To Directors And Employees
Share-Based Compensation
Share-based compensation expense	5,200	12,700	$ 9,800	24,900
Stock Options | Geetha Ramaswamy, Shankar Ramaswamy and Sarah Friedhoff
Share-Based Compensation
Share-based compensation expense	$ 900	1,000	$ 1,700	$ 2,400
Market-Based Performance Stock Options
Share-Based Compensation
Number of options outstanding (in shares)	1.5		1.5
Weighted average exercise price of options outstanding (in dollars per share)	$ 2.02		$ 2.02
Number of options granted (in shares)			0.6
Exercise price of options granted (in USD per share)			$ 2.98
Contractual term			10 years
Estimated grant date fair value of options granted			$ 1,100
Number of options vested (in shares)			0.4
Exercise price of options vested (in USD per share)			$ 1.46
Nonemployee Stock Options | RSI Employees
Share-Based Compensation
Number of options granted (in shares)			1	0.2
Share-based compensation expense	$ (23)	300	$ 400	$ 1,300
Total unrecognized compensation expense, stock options	1,200		$ 1,200
Remaining weighted-average service period			2 years 3 months 11 days
Common share awards | Shankar Ramaswamy | RSL
Share-Based Compensation
Share-based compensation expense	$ 7	$ 100	$ 100	$ 200
2015 Equity Incentive Plan
Share-Based Compensation
Number of shares reserved for grant (in shares)					24.8	20.5	16.5
Number of shares available for future grant (in shares)	8.2		8.2
2015 Equity Incentive Plan | Stock Options
Share-Based Compensation
Number of options outstanding (in shares)	15.8		15.8
Weighted average exercise price of options outstanding (in dollars per share)	$ 4.66		$ 4.66
Number of options granted (in shares)			2.1	8.8

Restructuring (Details)

Restructuring (Details) $ in Thousands	6 Months Ended
	Sep. 30, 2018USD ($)
Restructuring and Related Activities [Abstract]
Cash expenditures for one-time severance and related costs	$ (1,573)

Restructuring - Restructuring C

Restructuring - Restructuring Costs (Details) $ in Thousands	6 Months Ended
	Sep. 30, 2018USD ($)
Restructuring Reserve [Roll Forward]
Beginning balance	$ 2,460
Expenses, net	0
Cash	(1,573)
Non-cash	0
Ending balance	$ 887

Income Taxes (Details)

Income Taxes (Details)	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Effective income tax rate	(0.30%)	2.20%	(0.20%)	(0.70%)
Federal statutory income tax rate			0.00%

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Millions	3 Months Ended	6 Months Ended
	Sep. 30, 2018USD ($)ft²	Sep. 30, 2018USD ($)ft²
Operating Leased Assets [Line Items]
Rent expense | $	$ 0.4	$ 0.9
New York, New York Office Space
Operating Leased Assets [Line Items]
Office space rented (in sq ft) | ft²	19,554	19,554

Commitments and Contingencies_2

Commitments and Contingencies - Rent Obligations (Details) $ in Thousands	Sep. 30, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
Total	$ 3,576
2,019	895
2,020	1,791
2,021	$ 890