Arbutus Biopharma (ABUS) 10-Q 7 Nov 23 2023 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2023	Nov. 03, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	001-34949
Entity Registrant Name	ARBUTUS BIOPHARMA CORP
Entity Incorporation, State or Country Code	A1
Entity Tax Identification Number	98-0597776
Entity Address, Address Line One	701 Veterans Circle
Entity Address, City or Town	Warminster
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	18974
City Area Code	267
Local Phone Number	469-0914
Title of 12(b) Security	Common Shares, without par value
Trading Symbol	ABUS
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		167,695,247
Amendment Flag	false
Entity Central Index Key	0001447028
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 17,531	$ 30,776
Investments in marketable short-term securities	116,649	116,137
Accounts receivable	2,171	1,352
Prepaid expenses and other current assets	5,256	2,874
Total current assets	141,607	151,139
Property and equipment, net of accumulated depreciation of $11,541 (December 31, 2022: $10,801)	5,033	5,070
Investments in marketable securities, non-current	10,496	37,363
Right of use asset	1,502	1,744
Other non-current assets	3	103
Total assets	158,641	195,419
Current liabilities:
Accounts payable and accrued liabilities	9,806	16,029
Deferred license revenue, current	12,106	16,456
Lease liability, current	412	372
Total current liabilities	22,324	32,857
Liability related to sale of future royalties	8,110	10,365
Contingent consideration	7,373	7,531
Deferred license revenue, non-current	0	5,999
Lease liability, non-current	1,497	1,815
Total liabilities	39,304	58,567
Stockholders’ equity
Issued and outstanding: 167,695,247 (December 31, 2022: 157,455,363)	1,346,015	1,318,737
Additional paid-in capital	79,546	72,406
Deficit	(1,257,340)	(1,203,803)
Accumulated other comprehensive loss	(48,884)	(50,488)
Total stockholders’ equity	119,337	136,852
Total liabilities and stockholders’ equity	$ 158,641	$ 195,419

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Accumulated depreciation of property and equipment	$ 11,541	$ 10,801
Common shares, shares issued (in shares)	167,695,247	157,455,363
Common shares, shares outstanding (in shares)	167,695,247	157,455,363

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue
Revenues	$ 4,658	$ 5,952	$ 15,996	$ 32,774
Operating expenses
Research and development	20,169	20,055	56,136	61,459
General and administrative	5,842	3,493	17,374	13,585
Change in fair value of contingent consideration	205	215	(158)	624
Total operating expenses	26,216	23,763	73,352	75,668
Loss from operations	(21,558)	(17,811)	(57,356)	(42,894)
Interest income	1,494	694	4,223	1,249
Interest expense	(46)	(429)	(415)	(1,417)
Foreign exchange (gain) loss	6	(21)	11	(18)
Total other income (loss)	1,454	244	3,819	(186)
Loss before income taxes	(20,104)	(17,567)	(53,537)	(43,080)
Income tax expense	0	0	0	(4,444)
Net loss	$ (20,104)	$ (17,567)	$ (53,537)	$ (47,524)
Loss per share
Basic (in USD per share)	$ (0.12)	$ (0.12)	$ (0.32)
Diluted (in USD per share)	$ (0.12)	$ (0.12)	$ (0.32)	$ (0.32)
Weighted average number of common shares
Basic (in shares)	167,512,708	150,995,191	165,085,243
Diluted (in shares)	167,512,708	150,995,191	165,085,243	149,385,999
Comprehensive loss
Unrealized gain (loss) on available-for-sale securities	$ 584	$ (907)	$ 1,604	$ (2,669)
Comprehensive loss	(19,520)	(18,474)	(51,933)	(50,193)
Collaborations and licenses
Revenue
Revenues	3,935	3,607	13,329	27,381
Non-cash royalty revenue
Revenue
Revenues	$ 723	$ 2,345	$ 2,667	$ 5,393

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Stockholders’ Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Shares	Additional Paid-In Capital	Deficit	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2021		144,987,736
Beginning balance at Dec. 31, 2021	$ 169,439	$ 1,286,636	$ 65,485	$ (1,134,347)	$ (48,335)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	1,736		1,736
Certain fair value adjustments to liability stock option awards	21		21
Issuance of common shares pursuant to the Open Market Sale Agreement (in shares)		69,048
Issuance of common shares pursuant to the Open Market Sale Agreement	268	$ 268
Issuance of common shares pursuant to exercise of options (in shares)		5,000
Issuance of common shares pursuant to ESPP	8	$ 18	(10)
Issuance of common shares pursuant to ESPP (in shares)		86,501
Issuance of common shares pursuant to ESPP	236	$ 317	(81)
Issuance of common shares pursuant to Share Purchase Agreement		3,579,952
Issuance of common shares pursuant to Share Purchase Agreement	10,973	$ 10,973
Unrealized gain on available-for-sale securities	(1,071)				(1,071)
Net loss	(15,765)			(15,765)
Ending balance (in shares) at Mar. 31, 2022		148,728,237
Ending balance at Mar. 31, 2022	165,845	$ 1,298,212	67,151	(1,150,112)	(49,406)
Beginning balance (in shares) at Dec. 31, 2021		144,987,736
Beginning balance at Dec. 31, 2021	169,439	$ 1,286,636	65,485	(1,134,347)	(48,335)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(47,524)
Ending balance (in shares) at Sep. 30, 2022		152,711,702
Ending balance at Sep. 30, 2022	145,517	$ 1,307,654	70,738	(1,181,871)	(51,004)
Beginning balance (in shares) at Mar. 31, 2022		148,728,237
Beginning balance at Mar. 31, 2022	165,845	$ 1,298,212	67,151	(1,150,112)	(49,406)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	2,064		2,064
Certain fair value adjustments to liability stock option awards	3		3
Issuance of common shares pursuant to exercise of options (in shares)		66,025
Issuance of common shares pursuant to ESPP	113	$ 197	(84)
Unrealized gain on available-for-sale securities	(691)				(691)
Net loss	(14,192)			(14,192)
Ending balance (in shares) at Jun. 30, 2022		148,794,262
Ending balance at Jun. 30, 2022	153,142	$ 1,298,409	69,134	(1,164,304)	(50,097)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	1,715		1,715
Certain fair value adjustments to liability stock option awards	2		2
Issuance of common shares pursuant to the Open Market Sale Agreement (in shares)		3,832,717
Issuance of common shares pursuant to the Open Market Sale Agreement	8,973	$ 8,973
Issuance of common shares pursuant to ESPP (in shares)		84,723
Issuance of common shares pursuant to ESPP	159	$ 272	(113)
Unrealized gain on available-for-sale securities	(907)				(907)
Net loss	(17,567)			(17,567)
Ending balance (in shares) at Sep. 30, 2022		152,711,702
Ending balance at Sep. 30, 2022	$ 145,517	$ 1,307,654	70,738	(1,181,871)	(51,004)
Beginning balance (in shares) at Dec. 31, 2022	157,455,363	157,455,363
Beginning balance at Dec. 31, 2022	$ 136,852	$ 1,318,737	72,406	(1,203,803)	(50,488)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	2,131		2,131
Issuance of common shares pursuant to the Open Market Sale Agreement (in shares)		7,423,622
Issuance of common shares pursuant to the Open Market Sale Agreement	19,862	$ 19,862
Issuance of common shares pursuant to exercise of options (in shares)		101,356
Issuance of common shares pursuant to ESPP	259	$ 457	(198)
Issuance of common shares pursuant to ESPP (in shares)		151,852
Issuance of common shares pursuant to ESPP	296	$ 397	(101)
Unrealized gain on available-for-sale securities	854				854
Net loss	(16,339)			(16,339)
Ending balance (in shares) at Mar. 31, 2023		165,132,193
Ending balance at Mar. 31, 2023	$ 143,915	$ 1,339,453	74,238	(1,220,142)	(49,634)
Beginning balance (in shares) at Dec. 31, 2022	157,455,363	157,455,363
Beginning balance at Dec. 31, 2022	$ 136,852	$ 1,318,737	72,406	(1,203,803)	(50,488)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (53,537)
Ending balance (in shares) at Sep. 30, 2023	167,695,247	167,695,247
Ending balance at Sep. 30, 2023	$ 119,337	$ 1,346,015	79,546	(1,257,340)	(48,884)
Beginning balance (in shares) at Mar. 31, 2023		165,132,193
Beginning balance at Mar. 31, 2023	143,915	$ 1,339,453	74,238	(1,220,142)	(49,634)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	2,964		2,964
Issuance of common shares pursuant to the Open Market Sale Agreement (in shares)		1,790,546
Issuance of common shares pursuant to the Open Market Sale Agreement	4,742	$ 4,742
Unrealized gain on available-for-sale securities	166				166
Net loss	(17,094)			(17,094)
Ending balance (in shares) at Jun. 30, 2023		166,922,739
Ending balance at Jun. 30, 2023	134,693	$ 1,344,195	77,202	(1,237,236)	(49,468)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	2,483		2,483
Issuance of common shares pursuant to the Open Market Sale Agreement (in shares)		633,922
Issuance of common shares pursuant to the Open Market Sale Agreement	1,396	$ 1,396
Issuance of common shares pursuant to ESPP (in shares)		138,586
Issuance of common shares pursuant to ESPP	285	$ 424	(139)
Unrealized gain on available-for-sale securities	584				584
Net loss	$ (20,104)			(20,104)
Ending balance (in shares) at Sep. 30, 2023	167,695,247	167,695,247
Ending balance at Sep. 30, 2023	$ 119,337	$ 1,346,015	$ 79,546	$ (1,257,340)	$ (48,884)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flow (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
OPERATING ACTIVITIES
Net loss	$ (53,537)	$ (47,524)
Non-cash items:
Depreciation	1,045	1,120
Gain on sale of property and equipment	(20)	(20)
Stock-based compensation expense	7,578	5,515
Change in fair value of contingent consideration	(158)	624
Non-cash royalty revenue	(2,667)	(5,393)
Non-cash interest expense	412	1,413
Net accretion and amortization of investments in marketable securities	(1,577)	170
Net change in operating items:
Accounts receivable	(819)	(936)
Prepaid expenses and other assets	(2,040)	27
Accounts payable and accrued liabilities	(6,223)	1,456
Change in deferred license revenue	(10,349)	25,463
Other liabilities	(289)	(281)
Net cash used in operating activities	(68,644)	(18,366)
INVESTING ACTIVITIES
Purchase of investments in marketable securities	(56,490)	(117,266)
Disposition of investments in marketable securities	86,026	30,000
Proceeds from sale of property and equipment	20	20
Acquisition of property and equipment	(1,008)	(378)
Net cash provided by (used in) investing activities	28,548	(87,624)
FINANCING ACTIVITIES
Issuance of common shares pursuant to Share Purchase Agreement	0	10,973
Issuance of common shares pursuant to the Open Market Sale Agreement	26,000	9,241
Issuance of common shares pursuant to exercise of stock options	259	121
Issuance of common shares pursuant to exercise of ESPP	581	395
Net cash provided by financing activities	26,840	20,730
Effect of foreign exchange rate changes on cash and cash equivalents	11	(18)
Decrease in cash and cash equivalents	(13,245)	(85,278)
Cash and cash equivalents, beginning of period	30,776	109,282
Cash and cash equivalents, end of period	$ 17,531	$ 24,004

Nature of business and future o

Nature of business and future operations	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of business and future operations	Nature of business and future operations Description of the Business Arbutus Biopharma Corporation (“Arbutus” or the “Company”) is a clinical-stage biopharmaceutical company leveraging its extensive virology expertise to develop a functional cure for patients with chronic hepatitis B virus (“cHBV”). The Company believes the key to success in developing a functional cure involves suppressing HBV DNA, reducing surface antigen and boosting HBV-specific immune response. The Company’s pipeline of internally developed, proprietary compounds includes an RNAi therapeutic, imdusiran (AB-729), and an oral PD-L1 inhibitor, AB-101. Imdusiran has generated meaningful clinical data demonstrating an impact on both surface antigen reduction and reawakening of the HBV-specific immune response. Imdusiran is currently in two Phase 2a combination clinical trials. AB-101 is currently being evaluated in a Phase 1a/1b clinical trial. Additionally, the Company has identified compounds in its internal PD-L1 portfolio that could be used in oncology indications. Liquidity At September 30, 2023, the Company had an aggregate of $144.7 million in cash, cash equivalents and investments in marketable securities. The Company had no outstanding debt as of September 30, 2023. The Company believes it has sufficient cash resources to fund its operations for at least the next 12 months. The success of the Company is dependent on obtaining the necessary regulatory approvals to bring its products to market and achieve profitable operations. The Company’s research and development activities and the commercialization of its products are dependent on its ability to successfully complete these activities and to obtain adequate financing through a combination of financing activities and operations. It is not possible to predict either the outcome of the Company’s existing or future research and development programs or the Company’s ability to continue to fund these programs in the future.

Significant accounting policies

Significant accounting policies	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Significant accounting policies	Significant accounting policies Basis of presentation and principles of consolidation These unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles for interim financial statements and accordingly, do not include all disclosures required for annual financial statements. These statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto for the year ended December 31, 2022 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. These unaudited condensed consolidated financial statements include the accounts of Arbutus Biopharma Corporation and its one wholly-owned subsidiary, Arbutus Biopharma, Inc., and reflect, in the opinion of management, all adjustments and reclassifications necessary to fairly present the Company’s financial position as of September 30, 2023 and December 31, 2022, the Company’s results of operations for the three and nine months ended September 30, 2023 and 2022, and the Company’s cash flows for the nine months ended September 30, 2023 and 2022. Such adjustments are of a normal recurring nature. The results of operations for the three and nine months ended September 30, 2023 are not necessarily indicative of the results for the full year. These unaudited condensed consolidated financial statements follow the same significant accounting policies as those described in the notes to the audited consolidated financial statements of the Company for the year ended December 31, 2022, except as described below under Recent Accounting Pronouncements. All intercompany balances and transactions have been eliminated. Certain prior year amounts have been reclassified to conform to the current year presentation. Net loss per share Net loss per share is calculated based on the weighted average number of common shares outstanding. Diluted net loss per share does not differ from basic net loss per share for the three and nine months ended September 30, 2023 and 2022, since the effect of including potential common shares would be anti-dilutive. For the nine months ended September 30, 2023, potential common shares of 21.0 million pertaining to outstanding stock options and unvested restricted stock units were excluded from the calculation of net loss per share. A total of approximately 15.9 million outstanding stock options were excluded from the calculation for the nine months ended September 30, 2022. Revenue from collaborations and licenses The Company generates revenue through certain collaboration agreements and license agreements. Such agreements may require the Company to deliver various rights and/or services, including intellectual property rights or licenses and research and development services. Under such agreements, the Company is generally eligible to receive non-refundable upfront payments, funding for research and development services, milestone payments and royalties. The Company’s collaboration agreements fall under the scope of Accounting Standards Codification (“ASC”) Topic 808, Collaborative Arrangements (“ASC 808”), when both parties are active participants in the arrangement and are exposed to significant risks and rewards. For certain arrangements under the scope of ASC 808, the Company analogizes to ASC Topic 606, Revenue from Contracts with Customers (“ASC 606”), for some aspects, including for the delivery of a good or service (i.e., a unit of account). ASC 606 requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers under a five-step model: (i) identify 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 a performance obligation is satisfied. In contracts where the Company has more than one performance obligation to provide its customer with goods or services, each performance obligation is evaluated to determine whether it is distinct based on whether (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available and (ii) the good or service is separately identifiable from other promises in the contract. The consideration under the contract is then allocated between the distinct performance obligations based on their respective relative stand-alone selling prices. The estimated stand-alone selling price of each deliverable reflects the Company’s best estimate of what the selling price would be if the deliverable was regularly sold on a stand-alone basis and is determined by reference to market rates for the good or service when sold to others or by using an adjusted market assessment approach if the selling price on a stand-alone basis is not available. The consideration allocated to each distinct performance obligation is recognized as revenue when control is transferred to the customer for the related goods or services. Consideration associated with at-risk substantive performance milestones, including sales-based milestones, is recognized as revenue when it is probable that a significant reversal of the cumulative revenue recognized will not occur. Sales-based royalties received in connection with licenses of intellectual property are subject to a specific exception in the revenue standards, whereby the consideration is not included in the transaction price and recognized in revenue until the customer’s subsequent sales or usages occur. Deferred Revenue When consideration is received or is unconditionally due from a customer, collaborator or licensee prior to the Company completing its performance obligation to the customer, collaborator or licensee under the terms of a contract, deferred revenue is recorded. Deferred revenue expected to be recognized as revenue within the 12 months following the balance sheet date is classified as a current liability. Deferred revenue not expected to be recognized as revenue within the 12 months following the balance sheet date is classified as a long-term liability. In accordance with ASC Topic 210-20, Balance Sheet - Offsetting (“ASC 210-20”) the Company’s deferred revenue is offset by a contract asset as further discussed in Note 9. Segment information The Company operates as a single segment. Recent accounting pronouncements In June 2016, the Financial Accounting Standards Board issued Accounting Standards Update 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses in Financial Instruments (“ASC 326”). The guidance is effective for the Company beginning January 1, 2023 and it changes how entities account for credit losses on the financial assets and other instruments that are not measured at fair value through net income, including available-for-sale debt securities. The adoption of ASC 326 did not have a material impact on the consolidated financial statements. The Company has reviewed all other recently issued standards and has determined that such standards will not have a material impact on the Company’s financial statements or do not otherwise apply to the Company’s operations.

Fair value measurements

Fair value measurements	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurements The Company measures certain financial instruments and other items at fair value. To determine the fair value, the Company uses the fair value hierarchy for inputs used in measuring fair value that maximize the use of observable inputs and minimize the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs are inputs market participants would use to value an asset or liability and are developed based on market data obtained from independent sources. Unobservable inputs are inputs based on assumptions about the factors market participants would use to value an asset or liability. The three levels of inputs that may be used to measure fair value are as follows: • Level 1 inputs are quoted market prices for identical instruments available in active markets. • Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability either directly or indirectly. If the asset or liability has a contractual term, the input must be observable for substantially the full term. An example includes quoted market prices for similar assets or liabilities in active markets. • Level 3 inputs are unobservable inputs for the asset or liability and will reflect management’s assumptions about market assumptions that would be used to price the asset or liability. Assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurements. Changes in the observability of valuation inputs may result in a reclassification of levels for certain securities within the fair value hierarchy. The carrying values of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair values due to the immediate or short-term maturity of these financial instruments. To determine the fair value of the contingent consideration (Note 8), the Company uses a probability weighted assessment of the likelihood the milestones would be met and the estimated timing of such payments, and then the potential contingent payments are discounted to their present value using a probability adjusted discount rate that reflects the early stage nature of the development program, the time to complete the program development, and overall biotech indices. The Company determined the fair value of the contingent consideration was $7.4 million as of September 30, 2023 and the decrease of $0.2 million from December 31, 2022 has been recorded as a component of total operating expenses in the statements of operations and comprehensive loss for the nine months ended September 30, 2023. The assumptions used in the discounted cash flow model are level 3 inputs as defined above. The Company assessed the sensitivity of the fair value measurement to changes in these unobservable inputs, and determined that changes within a reasonable range would not result in a materially different assessment of fair value. The following tables present information about the Company’s assets and liabilities that are measured at fair value on a recurring basis, and indicates the fair value hierarchy of the valuation techniques used to determine such fair value: Level 1 Level 2 Level 3 Total As of September 30, 2023 (in thousands) Assets Cash and cash equivalents $ 17,531 $ — $ — $ 17,531 Investments in marketable securities, current — 116,649 — 116,649 Investments in marketable securities, non-current — 10,496 — 10,496 Total $ 17,531 $ 127,145 $ — $ 144,676 Liabilities Contingent consideration — — 7,373 7,373 Total $ — $ — $ 7,373 $ 7,373 Level 1 Level 2 Level 3 Total As of December 31, 2022 (in thousands) Assets Cash and cash equivalents $ 30,776 $ — $ — $ 30,776 Investments in marketable securities, current — 116,137 — 116,137 Investments in marketable securities, non-current — 37,363 — 37,363 Total $ 30,776 $ 153,500 $ — $ 184,276 Liabilities Contingent consideration — — 7,531 7,531 Total $ — $ — $ 7,531 $ 7,531 The following table presents the changes in fair value of the Company’s contingent consideration: Liability at beginning of the period Change in fair value of liability Liability at end of the period (in thousands) Nine Months Ended September 30, 2023 $ 7,531 $ (158) $ 7,373 Nine Months Ended September 30, 2022 $ 5,298 $ 624 $ 5,922

Investments in marketable secur

Investments in marketable securities	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Investments in marketable securities	Investments in marketable securities Investments in marketable securities consisted of the following: Amortized Cost Gross Unrealized Gain (1) Gross Unrealized Loss (1) Fair Value As of September 30, 2023 (in thousands) Cash equivalents Money market $ 10,805 $ — $ — $ 10,805 Total $ 10,805 $ — $ — $ 10,805 Investments in marketable short-term securities US government agency bonds $ 31,706 $ — $ (158) $ 31,548 US corporate bonds 57,692 — (341) 57,351 US treasury bills 10,940 — (2) 10,938 Yankee bonds 2,000 — (32) 1,968 US government bonds 14,985 — (141) 14,844 Total $ 117,323 $ — $ (674) $ 116,649 Investments in marketable long-term securities US corporate bonds 10,522 — (29) 10,496 Total $ 10,522 $ 3 $ (29) $ 10,496 (1) Gross unrealized gain (loss) is pre-tax and is reported in accumulated other comprehensive loss. Amortized Cost Gross Unrealized Gain (1) Gross Unrealized Loss (1) Fair Value As of December 31, 2022 (in thousands) Cash equivalents Money market $ 23,218 $ — $ — $ 23,218 Total $ 23,218 $ — $ — $ 23,218 Investments in marketable short-term securities US government agency bonds $ 26,686 $ — $ (424) $ 26,262 US corporate bonds 27,144 — (303) 26,841 US treasury bills 8,483 — (16) 8,467 US government bonds $ 55,361 $ — $ (794) $ 54,567 Total $ 117,674 $ — $ (1,537) $ 116,137 Investments in marketable long-term securities US government agency bonds $ 3,724 $ — $ (130) $ 3,594 US treasury bills 25,433 — (336) 25,097 US government bonds 8,972 — (300) 8,672 Total $ 38,129 $ — $ (766) $ 37,363 (1) Gross unrealized gain (loss) is pre-tax and is reported in accumulated other comprehensive loss. The contractual term to maturity of the $116.6 million of short-term marketable securities held by the Company as of September 30, 2023 is less than one year. As of September 30, 2023, the Company held $10.5 million of long-term marketable securities with contractual maturities of more than one year, but less than five years. As of December 31, 2022, the Company’s $116.1 million of short-term marketable securities had contractual maturities of less than one year, while the Company’s $37.4 million of long-term marketable securities had maturities of more than one year, but less than five years. At September 30, 2023 and December 31, 2022, the Company had 40 and 53, respectively, available-for-sale investment debt securities in an unrealized loss position without an allowance for credit losses. Unrealized losses on the Company’s investments in debt securities have not been recognized into income as the issuers’ bonds are of high credit quality and the decline in fair value is largely due to market conditions and/or changes in interest rates. The Company does not intend to sell and it is more likely than not that the Company will not be required to sell the securities prior to the anticipated recovery of their amortized cost basis. The issuers continue to make timely interest payments on the bonds. The fair value is expected to recover as the bonds approach maturity. Accrued interest receivable on investments in marketable securities of $0.6 million at both September 30, 2023 and December 31, 2022 is included in prepaid expenses and other current assets. The Company had realized gains of less than $0.1 million for both the three and nine months ended September 30, 2023 and 2022.

Investment in Genevant

Investment in Genevant	9 Months Ended
	Sep. 30, 2023
Equity Method Investments and Joint Ventures [Abstract]
Investment in Genevant	Investment in Genevant In April 2018, the Company entered into an agreement with Roivant Sciences Ltd., its largest shareholder, to launch Genevant Sciences Ltd. (“Genevant”), a company focused on the discovery, development, and commercialization of a broad range of RNA-based therapeutics enabled by the Company’s lipid nanoparticle (“LNP”) and ligand conjugate delivery technologies. The Company licensed exclusive rights to its LNP and ligand conjugate delivery platforms to Genevant for RNA-based applications outside of HBV, except to the extent certain rights had already been licensed to other third parties (the “Genevant License”). The Company retained all rights to its LNP and conjugate delivery platforms for HBV. Under the Genevant License, as amended, if a third party sublicensee of intellectual property licensed by Genevant from the Company commercializes a sublicensed product, the Company becomes entitled to receive a specified percentage of certain revenue that may be received by Genevant for such sublicense, including royalties, commercial milestones and other sales-related revenue, or, if less, tiered low single-digit royalties on net sales of the sublicensed product. The specified percentage is 20% in the case of a mere sublicense (i.e., naked sublicense) by Genevant without additional contribution and 14% in the case of a bona fide collaboration with Genevant. Additionally, if Genevant receives proceeds from an action for infringement by any third parties of the Company’s intellectual property licensed to Genevant, the Company would be entitled to receive, after deduction of litigation costs, 20% of the proceeds received by Genevant or, if less, tiered low single-digit royalties on net sales of the infringing product (inclusive of the proceeds from litigation or settlement, which would be treated as net sales). The Company accounts for its interest in Genevant as equity securities without readily determinable fair values. Accordingly, an estimate of the fair value of the securities is based on the original cost less previously recognized equity method losses, less impairments, plus or minus changes resulting from observable price changes in orderly transactions for identical or a similar Genevant securities. As of September 30, 2023, the carrying value of the Company’s investment in Genevant was zero and the Company owned approximately 16% of the common equity of Genevant.

Accounts payable and accrued li

Accounts payable and accrued liabilities	9 Months Ended
	Sep. 30, 2023
Payables and Accruals [Abstract]
Accounts payable and accrued liabilities	Accounts payable and accrued liabilities Accounts payable and accrued liabilities are comprised of the following: September 30, 2023 December 31, 2022 (in thousands) Trade accounts payable $ 2,260 $ 3,520 Research and development accruals 4,210 8,261 Professional fee accruals 691 512 Payroll accruals 2,645 3,730 Other accrued liabilities — 6 Total accounts payable and accrued liabilities $ 9,806 $ 16,029

Sale of future royalties

Sale of future royalties	9 Months Ended
	Sep. 30, 2023
Other Liabilities Disclosure [Abstract]
Sale of future royalties	Sale of future royalties On July 2, 2019, the Company entered into a Purchase and Sale Agreement (the “Agreement”) with the Ontario Municipal Employees Retirement System (“OMERS”), pursuant to which the Company sold to OMERS part of its royalty interest on future global net sales of ONPATTRO ® (Patisiran) (“ONPATTRO”), an RNA interference therapeutic currently being sold by Alnylam Pharmaceuticals, Inc. (“Alnylam”). ONPATTRO utilizes the Company’s LNP technology, which was licensed to Alnylam pursuant to the Cross-License Agreement, dated November 12, 2012, by and between the Company and Alnylam (the “LNP License Agreement”). Under the terms of the LNP License Agreement, the Company is entitled to tiered royalty payments on global net sales of ONPATTRO ranging from 1.00% to 2.33% after offsets, with the highest tier applicable to annual net sales above $500 million. This royalty interest was sold to OMERS, effective as of January 1, 2019, for $20 million in gross proceeds before advisory fees. OMERS will retain this entitlement until it has received $30 million in royalties, at which point 100% of such royalty interest on future global net sales of ONPATTRO will revert to the Company. OMERS has assumed the risk of collecting up to $30 million of future royalty payments from Alnylam and the Company is not obligated to reimburse OMERS if they fail to collect any such future royalties. The $30 million in royalties to be paid to OMERS is accounted for as a liability, with the difference between the liability and the gross proceeds received accounted for as a discount. The discount, as well as $1.5 million of transaction costs, will be amortized as interest expense based on the projected balance of the liability as of the beginning of each period. As of September 30, 2023, the Company estimated an effective annual interest rate of approximately 2.3%. Over the course of the Agreement, the actual interest rate will be affected by the amount and timing of royalty revenue recognized and changes in the timing of forecasted royalty revenue. On a quarterly basis, the Company will reassess the expected timing of the royalty revenue, recalculate the amortization and effective interest rate and adjust the accounting prospectively as needed. The Company recognizes non-cash royalty revenue related to the sales of ONPATTRO during the term of the Agreement. As royalties are remitted to OMERS from Alnylam, the balance of the recognized liability is effectively repaid over the life of the Agreement. From the inception of the royalty sale through September 30, 2023, the Company has recorded an aggregate of $21.5 million of non-cash royalty revenue for royalties earned by OMERS. There are a number of factors that could materially affect the amount and timing of royalty payments from Alnylam, none of which are within the Company’s control. During the nine months ended September 30, 2023, the Company recognized non-cash royalty revenue of $2.7 million and related non-cash interest expense of $0.4 million. During the nine months ended September 30, 2022, the Company recognized non-cash royalty revenue of $5.4 million and related non-cash interest expense of $1.4 million. The table below shows the activity related to the net liability for the nine months ended September 30, 2023 and 2022: Nine Months Ended September 30, 2023 2022 (in thousands) Net liability related to sale of future royalties - beginning balance $ 10,365 $ 16,296 Non-cash royalty revenue (2,667) (5,393) Non-cash interest expense 412 1,413 Net liability related to sale of future royalties - ending balance $ 8,110 $ 12,316 In addition to the royalty from the LNP License Agreement, the Company is also receiving a second royalty interest ranging from 0.75% to 1.125% on global net sales of ONPATTRO, with 0.75% applying to sales greater than $500 million, originating from a settlement agreement and subsequent license agreement with Acuitas Therapeutics, Inc. (“Acuitas”). The royalty from Acuitas has been retained by the Company and was not part of the royalty sale to OMERS.

Contingencies and commitments

Contingencies and commitments	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Contingencies and commitments	Contingencies and commitments Stock Purchase Agreement with Enantigen In October 2014, Arbutus Inc., the Company’s wholly-owned subsidiary, acquired all of the outstanding shares of Enantigen Therapeutics, Inc. (“Enantigen”) pursuant to a stock purchase agreement. The amount paid to Enantigen’s selling shareholders could be up to an additional $102.5 million in sales performance milestones in connection with the sale of the first commercialized product by the Company for the treatment of HBV, regardless of whether such product is based upon assets acquired under this agreement, and a low single-digit royalty on net sales of such first commercialized HBV product, up to a maximum royalty payment of $1.0 million that, if paid, would be offset against the Company’s milestone payment obligations. Certain other development milestones related to the acquisition were tied to programs which are no longer under development by the Company, and therefore the contingency related to those development milestones is zero. The contingent consideration is a financial liability and is measured at its fair value at each reporting period, with any changes in fair value from the previous reporting period recorded in the statements of operations and comprehensive loss (see Note 3). The fair value of the contingent consideration was $7.4 million as of September 30, 2023.

Collaborations, contracts and l

Collaborations, contracts and licensing agreements	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Collaborations, contracts and licensing agreements	Collaborations, contracts and licensing agreements Collaborations Qilu Pharmaceutical Co., Ltd. In December 2021, the Company entered into a technology transfer and licensing agreement (the “License Agreement”) with Qilu Pharmaceutical Co., Ltd. (“Qilu”), pursuant to which the Company granted Qilu a sublicensable, royalty-bearing license, under certain intellectual property owned by the Company, which is non-exclusive as to development and manufacturing and exclusive with respect to commercialization of imdusiran, including pharmaceutical products that include imdusiran, for the treatment or prevention of hepatitis B in China, Hong Kong, Macau and Taiwan (the “Territory”). In partial consideration for the rights granted by the Company, Qilu paid the Company a one-time upfront cash payment of $40.0 million, net of withholding taxes, on January 5, 2022, and agreed to pay the Company milestone payments totaling up to $245.0 million, net of withholding taxes, upon the achievement of certain technology transfer, development, regulatory and commercialization milestones. Qilu paid $4.4 million of withholding taxes to the Chinese taxing authority on the Company’s behalf, related to the upfront cash payment. In addition, Qilu agreed to pay the Company double-digit royalties into the low twenties percent based upon annual net sales of imdusiran in the Territory. The royalties are payable on a product-by-product and region-by-region basis, subject to certain limitations. Qilu is responsible for all costs related to developing, obtaining regulatory approval for, and commercializing imdusiran for the treatment or prevention of hepatitis B in the Territory. Qilu is required to use commercially reasonable efforts to develop, seek regulatory approval for, and commercialize at least one imdusiran product candidate in the Territory. A joint development committee has been established between the Company and Qilu to coordinate and review the development, manufacturing and commercialization plans. Both parties also have entered into a supply agreement and related quality agreement pursuant to which the Company will manufacture or have manufactured and supply Qilu with all quantities of imdusiran necessary for Qilu to develop and commercialize in the Territory until the Company has completed manufacturing technology transfer to Qilu and Qilu has received all approvals required for it or its designated contract manufacturing organization to manufacture imdusiran in the Territory. Concurrent with the execution of the License Agreement, the Company entered into a Share Purchase Agreement (the “Share Purchase Agreement”) with Anchor Life Limited, a company established pursuant to the applicable laws and regulations of Hong Kong and an affiliate of Qilu (the “Investor”), pursuant to which the Investor purchased 3,579,952 of the Company’s common shares at a purchase price of USD $4.19 per share, which was a 15% premium on the thirty-day average closing price of the common shares as of the close of trading on December 10, 2021 (the “Share Transaction”). The Company received $15.0 million of gross proceeds from the Share Transaction on January 6, 2022. The common shares sold to the Investor in the Share Transaction represented approximately 2.5% of the common shares outstanding immediately prior to the execution of the Share Purchase Agreement. The License Agreement falls under the scope of ASC 808 as both parties are active participants in the arrangement and are exposed to significant risks and rewards. While this arrangement is in the scope of ASC 808, the Company analogizes to ASC 606 for some aspects of this arrangement, including for the delivery of a good or service (i.e., a unit of account). In accordance with the guidance, the Company identified the following commitments under the arrangement: (i) rights to develop, use, sell, have sold, offer for sale and import any product comprised of Licensed Product (as defined in the License Agreement) (the “Qilu License”) and (ii) drug supply obligations and manufacturing technology transfer (the “Manufacturing Obligations”). The Company determined that these two commitments are not distinct performance obligations for purposes of recognizing revenue as the manufacturing process is highly specialized and Qilu would not be able to benefit from the Qilu License without the Company’s involvement in the manufacturing activities until the transfer of the manufacturing know-how is complete. As such, the Company will combine these commitments into one performance obligation to which the transaction price will be allocated to and will recognize this transaction price associated with the bundled performance obligation over time using an inputs method based on labor hours expended by the Company on its Manufacturing Obligations. The Company determined the initial transaction price of the combined performance obligation to be $49.3 million, which includes the $40.0 million upfront fee, $4.4 million of withholding taxes paid by Qilu on behalf of the Company, the premium paid for the Share Transaction of $4.1 million, and $0.8 million associated with certain manufacturing costs expected to be reimbursed by Qilu. The Company determined the Milestone Payments to be variable consideration subject to constraint at inception. At the end of each subsequent reporting period, the Company will reevaluate the probability of achievement of the future development, regulatory, and sales milestones subject to constraint and, if necessary, will adjust its estimate of the overall transaction price. Any such adjustments will be recorded on a cumulative catch-up basis, which would affect revenues and earnings in the period of adjustment. The following table outlines the transaction price and the changes to the related asset and liability balances during the nine months ended September 30, 2023: Nine Months Ended September 30, 2023 Transaction Price Cumulative Collaboration Revenue Recognized Deferred License Revenue (in thousands) Combined performance obligation $ 49,270 $ 36,364 $ 12,906 Less contract asset (800) Total deferred license revenue 12,106 Less current portion of deferred license revenue 12,106 Non-current deferred license revenue $ — The Company recognized $3.2 million and $10.3 million of revenue based on labor hours expended by the Company on its Manufacturing Obligations during the three and nine months ended September 30, 2023, respectively, and $2.4 million and $23.0 million during the three and nine months ended September 30, 2022, respectively. As of September 30, 2023, the balance of the deferred license revenue was $12.9 million, which, in accordance with ASC 210-20, was partially offset by the contract asset associated with the manufacturing cost reimbursement of $0.8 million, resulting in a net deferred license revenue liability of $12.1 million. The $4.4 million of withholding taxes paid by Qilu on behalf of the Company was recorded as income tax expense during the twelve months ended December 31, 2022. The Company incurred $0.6 million of incremental costs in obtaining the Qilu License, which the Company capitalized in other current assets and other assets and amortizes as a component of general and administrative expense commensurate with the recognition of the combined performance obligation. The Company recognized amortization expense of less than $0.1 million and $0.1 million for the three and nine months ended September 30, 2023, respectively, and less than $0.1 million and $0.3 million for the three and nine months ended September 30, 2022, respectively. The Company reevaluates the transaction price and the total estimated labor hours expected to be incurred to satisfy the performance obligations and adjusts the deferred revenue at the end of each reporting period. Such changes will result in a change to the amount of collaboration revenue recognized and deferred revenue. Barinthus Biotherapeutics plc In July 2021, the Company entered into a clinical collaboration agreement with Barinthus Biotherapeutics plc (“Barinthus”), formerly Vaccitech plc, to evaluate imdusiran followed by Barinthus’ VTP-300, an HBV antigen specific immunotherapy, and ongoing nucleos(t)ide analogue therapy in patients with cHBV. Recently, the clinical trial was amended and is now dosing patients in an additional treatment arm that includes an approved PD-1 monoclonal antibody inhibitor, nivolumab (Opdivo ® ). The Company is responsible for managing this Phase 2a proof-of-concept clinical trial, subject to oversight by a joint development committee comprised of representatives from the Company and Barinthus. The Company and Barinthus retain full rights to their respective product candidates and will split all costs associated with the clinical trial. The Company incurred $0.7 million and $1.6 million of expenses, net of reimbursements from Barinthus, related to the collaboration during the three and nine months ended September 30, 2023, respectively, and reflected those costs in research and development in the statements of operations and comprehensive loss. The Company incurred $0.3 million and $0.7 million of such costs for the same respective periods in 2022. Assembly Biosciences, Inc. In August 2020, the Company entered into a clinical collaboration agreement with Assembly Biosciences, Inc. (“Assembly”) to evaluate imdusiran in combination with Assembly’s first-generation HBV core inhibitor (capsid inhibitor) candidate vebicorvir (“VBR”) and standard-of-care NA therapy for the treatment of patients with HBV infection. After completing enrollment in the Phase 2a proof-of-concept clinical trial, in July 2022, Assembly announced its plan to discontinue development of VBR. In consultation with Assembly, the Company continued dosing patients in this clinical trial until completion of the final, on-treatment visit at week 48, at which point both parties mutually agreed to discontinue the clinical trial. The Company and Assembly shared in the costs of the collaboration. The Company incurred $0.1 million and $1.4 million of expenses related to the collaboration during the three and nine months ended September 30, 2023, respectively, and $0.6 million and $2.1 million during the three and nine months ended September 30, 2022, respectively. Those costs are reflected in research and development in the statements of operations and comprehensive loss. Except to the extent necessary to carry out Assembly’s responsibilities with respect to the collaboration trial, the Company has not provided any license grant to Assembly for use of its imdusiran compound. X-Chem, Inc. and Proteros biostructures GmbH In March 2021, the Company entered into a discovery research and license agreement, as amended, with X-Chem, Inc. (“X-Chem”) and Proteros biostructures GmbH (“Proteros”) to focus on the discovery of novel inhibitors targeting the SARS-CoV-2 nsp5 main protease (“Mpro”). The agreement was designed to accelerate the development of pan-coronavirus agents to treat COVID-19 and potential future coronavirus outbreaks. This collaboration brought together the Company’s expertise in the discovery and development of antiviral agents with X-Chem’s industry leading DNA-encoded library (DEL) technology and Proteros’ protein sciences, biophysics and structural biology capabilities and provides important synergies to potentially identify safe and effective therapies against coronaviruses including SARS-CoV-2. The collaboration allowed for the rapid screening of one of the largest small molecule libraries against Mpro (an essential protein required for the virus to replicate itself) and the use of state-of-the-art structure guided methods to rapidly optimize Mpro inhibitors to progress to clinical candidates. Through this collaboration, the Company identified and obtained a worldwide exclusive license to several molecules that inhibit Mpro, a validated target for the treatment of COVID-19 and potential future coronavirus outbreaks. In the fourth quarter of 2022, the Company nominated AB-343 as its lead candidate that inhibits Mpro. The agreement, as amended, provided for payments by the Company to X-Chem and Proteros upon satisfaction of certain development, regulatory and commercial milestones, as well as royalties on sales. The Company incurred less than $0.1 million and $1.0 million of expenses related to the collaboration during the three and nine months ended September 30, 2023, respectively, and $0.6 million and $0.9 million during the three and nine months ended September 30, 2022, respectively. Those costs are reflected in research and development in the statements of operations and comprehensive loss. During the third quarter of 2023, the Company discontinued its efforts to identify and develop a coronavirus combination therapy due to an unfavorable pharmacokinetic (PK) profile noted in the IND-enabling studies for AB-343. The Company also terminated this discovery research and license agreement with X-Chem and Proteros. Royalty Entitlements Alnylam Pharmaceuticals, Inc. and Acuitas Therapeutics, Inc. The Company has two royalty entitlements to Alnylam’s global net sales of ONPATTRO. In 2012, the Company entered into the LNP License Agreement with Alnylam that entitles Alnylam to develop and commercialize products with the Company’s LNP technology. Alnylam launched ONPATTRO, the first approved application of the Company’s LNP technology, in 2018. Under the terms of this license agreement, the Company is entitled to tiered royalty payments on global net sales of ONPATTRO ranging from 1.00% - 2.33% after offsets, with the highest tier applicable to annual net sales above $500 million. This royalty interest was sold to OMERS, effective as of January 1, 2019, for $20 million in gross proceeds before advisory fees. OMERS will retain this entitlement until it has received $30 million in royalties, at which point 100% of this royalty entitlement on future global net sales of ONPATTRO will revert back to the Company. OMERS has assumed the risk of collecting up to $30 million of future royalty payments from Alnylam and the Company is not obligated to reimburse OMERS if they fail to collect any such future royalties. If this royalty entitlement reverts to the Company, it has the potential to provide an active royalty stream or to be otherwise monetized again in full or in part. From the inception of the royalty sale through September 30, 2023, an aggregate of $21.5 million of royalties have been earned by OMERS. The Company also is receiving a second royalty interest of 0.75% to 1.125% on global net sales of ONPATTRO, with 0.75% applying to sales greater than $500 million, originating from a settlement agreement and subsequent license agreement with Acuitas. This royalty entitlement from Acuitas has been retained by the Company and was not part of the royalty entitlement sale to OMERS. Revenues are summarized in the following table: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) (in thousands) Revenue from collaborations and licenses Acuitas Therapeutics, Inc. $ 714 $ 1,256 $ 2,980 $ 4,339 Qilu Pharmaceutical Co., Ltd. 3,221 2,352 10,349 23,007 Other milestone and royalty payments — — — 35 Non-cash royalty revenue Alnylam Pharmaceuticals, Inc. 723 2,344 2,667 5,393 Total revenue $ 4,658 $ 5,952 $ 15,996 $ 32,774

Shareholders_ equity

Shareholders’ equity	9 Months Ended
	Sep. 30, 2023
Stockholders' Equity Note [Abstract]
Shareholders’ equity	Shareholders’ equity Authorized share capital The Company’s authorized share capital consists of an unlimited number of common shares and preferred shares, without par value, and 1,164,000 Series A participating convertible preferred shares, without par value. Open Market Sale Agreement The Company has an Open Market Sale Agreement with Jefferies LLC dated December 20, 2018, as amended by Amendment No. 1, dated December 20, 2019, Amendment No. 2, dated August 7, 2020 and Amendment No. 3, dated March 4, 2021 (as amended, the “Sale Agreement”), under which the Company may issue and sell common shares, from time to time. On December 23, 2019, the Company filed a shelf registration statement on Form S-3 with the Securities and Exchange Commission (the “SEC”) (File No. 333-235674) and accompanying base prospectus, which was declared effective by the SEC on January 10, 2020 (the “January 2020 Registration Statement”), for the offer and sale of up to $150.0 million of the Company’s securities. The January 2020 Registration Statement also contained a prospectus supplement for an offering of up to $50.0 million of the Company’s common shares pursuant to the Sale Agreement. This prospectus supplement was fully utilized during 2020. On August 7, 2020, the Company filed a prospectus supplement with the SEC (the “August 2020 Prospectus Supplement”) for an offering of up to an additional $75.0 million of its common shares pursuant to the Sale Agreement under the January 2020 Registration Statement. The August 2020 Prospectus Supplement was fully utilized during 2020. The January 2020 Registration Statement expired in January 2023. On August 28, 2020, the Company filed a shelf registration statement on Form S-3 with the SEC (File No. 333-248467) and accompanying base prospectus, which was declared effective by the SEC on October 22, 2020 (the “October 2020 Registration Statement”), for the offer and sale of up to $200.0 million of the Company’s securities. On March 4, 2021, the Company filed a prospectus supplement with the SEC (the “March 2021 Prospectus Supplement”) for an offering of up to an additional $75.0 million of its common shares pursuant to the Sale Agreement under the October 2020 Registration Statement. The March 2021 Prospectus Supplement was fully utilized during 2021. On October 8, 2021, the Company filed a prospectus supplement with the SEC (the “October 2021 Prospectus Supplement”) for an offering of up to an additional $75.0 million of its common shares pursuant to the Sale Agreement under the October 2020 Registration Statement. The October 2020 Registration Statement expired in October 2023 with $29.3 million that was not utilized under the October 2021 Prospectus Supplement. On November 4, 2021, the Company filed a shelf registration statement on Form S-3 with the SEC (File No. 333-260782) and accompanying base prospectus, which was declared effective by the SEC on November 18, 2021 (the “November 2021 Registration Statement”), for the offer and sale of up to $250.0 million of the Company’s securities. On March 3, 2022, the Company filed a prospectus supplement with the SEC (the “March 2022 Prospectus Supplement”) for an offering of up to an additional $100.0 million of its common shares pursuant to the Sale Agreement under: (i) the January 2020 Registration Statement; (ii) the October 2020 Registration Statement; and (iii) the November 2021 Registration Statement, of which only the November 2021 Registration Statement remains active. During the three and nine months ended September 30, 2023, the Company issued 633,922 and 9,848,090 common shares pursuant to the Sale Agreement, respectively, resulting in net proceeds of approximately $1.4 million and $26.0 million, respectively. During the three and nine months ended September 30, 2022, the Company issued 3,832,717 common shares pursuant to the Sale Agreement, resulting in net proceeds of $9.0 million. As of September 30, 2023, there was approximately $104.3 million of common shares remaining available in aggregate under the October 2021 Prospectus Supplement and March 2022 Prospectus Supplement. In October 2023, the October 2020 Registration Statement expired with $29.3 million that was not utilized under the October 2021 Prospectus Supplement, leaving $75.0 million remaining available under the March 2022 Prospectus Supplement pursuant to the November 2021 Registration Statement. Stock-based compensation The table below summarizes information about the Company’s stock-based compensation for the three and nine months ended September 30, 2023 and 2022 and the expense recognized in the condensed consolidated statements of operations: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands, except share and per share data) Stock options Options granted during period 784,240 62,700 5,082,640 4,797,000 Weighted average exercise price $ 2.25 $ 2.37 $ 2.78 $ 2.77 Restricted stock units (“RSUs”) Restricted stock units granted during period — — 1,344,550 — Grant date fair value $ — $ — $ 2.90 $ — Stock compensation expense Research and development $ 1,002 $ 736 $ 2,854 $ 2,191 General and administrative 1,481 978 4,724 3,324 Total stock compensation expense $ 2,483 $ 1,714 $ 7,578 $ 5,515 The RSUs vest over three years in equal annual installments beginning one year from the grant date.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent eventsOn November 6, 2023, the Company reduced its workforce by 24% primarily affecting its research function. As a result, the Company will incur a one-time restructuring charge of approximately $1.1 million that will be recorded in the fourth quarter of 2023. The Company has maintained a group of research scientists as it remains committed to continuing discovery research in HBV.

Significant accounting polici_2

Significant accounting policies (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Basis of presentation	Basis of presentation and principles of consolidation These unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles for interim financial statements and accordingly, do not include all disclosures required for annual financial statements. These statements should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto for the year ended December 31, 2022 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022. These unaudited condensed consolidated financial statements include the accounts of Arbutus Biopharma Corporation and its one wholly-owned subsidiary, Arbutus Biopharma, Inc., and reflect, in the opinion of management, all adjustments and reclassifications necessary to fairly present the Company’s financial position as of September 30, 2023 and December 31, 2022, the Company’s results of operations for the three and nine months ended September 30, 2023 and 2022, and the Company’s cash flows for the nine months ended September 30, 2023 and 2022. Such adjustments are of a normal recurring nature. The results of operations for the three and nine months ended September 30, 2023 are not necessarily indicative of the results for the full year. These unaudited condensed consolidated financial statements follow the same significant accounting policies as those described in the notes to the audited consolidated financial statements of the Company for the year ended December 31, 2022, except as described below under Recent Accounting Pronouncements.
Principles of consolidation	All intercompany balances and transactions have been eliminated. Certain prior year amounts have been reclassified to conform to the current year presentation.
Net loss attributable to common shareholders per share	Net loss per shareNet loss per share is calculated based on the weighted average number of common shares outstanding. Diluted net loss per share does not differ from basic net loss per share for the three and nine months ended September 30, 2023 and 2022, since the effect of including potential common shares would be anti-dilutive. For the nine months ended September 30, 2023, potential common shares of 21.0 million pertaining to outstanding stock options and unvested restricted stock units were excluded from the calculation of net loss per share. A total of approximately 15.9 million outstanding stock options were excluded from the calculation for the nine months ended September 30, 2022.
Revenue from collaborations and licenses and Deferred Revenue	Revenue from collaborations and licenses The Company generates revenue through certain collaboration agreements and license agreements. Such agreements may require the Company to deliver various rights and/or services, including intellectual property rights or licenses and research and development services. Under such agreements, the Company is generally eligible to receive non-refundable upfront payments, funding for research and development services, milestone payments and royalties. The Company’s collaboration agreements fall under the scope of Accounting Standards Codification (“ASC”) Topic 808, Collaborative Arrangements (“ASC 808”), when both parties are active participants in the arrangement and are exposed to significant risks and rewards. For certain arrangements under the scope of ASC 808, the Company analogizes to ASC Topic 606, Revenue from Contracts with Customers (“ASC 606”), for some aspects, including for the delivery of a good or service (i.e., a unit of account). ASC 606 requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers under a five-step model: (i) identify 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 a performance obligation is satisfied. In contracts where the Company has more than one performance obligation to provide its customer with goods or services, each performance obligation is evaluated to determine whether it is distinct based on whether (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available and (ii) the good or service is separately identifiable from other promises in the contract. The consideration under the contract is then allocated between the distinct performance obligations based on their respective relative stand-alone selling prices. The estimated stand-alone selling price of each deliverable reflects the Company’s best estimate of what the selling price would be if the deliverable was regularly sold on a stand-alone basis and is determined by reference to market rates for the good or service when sold to others or by using an adjusted market assessment approach if the selling price on a stand-alone basis is not available. The consideration allocated to each distinct performance obligation is recognized as revenue when control is transferred to the customer for the related goods or services. Consideration associated with at-risk substantive performance milestones, including sales-based milestones, is recognized as revenue when it is probable that a significant reversal of the cumulative revenue recognized will not occur. Sales-based royalties received in connection with licenses of intellectual property are subject to a specific exception in the revenue standards, whereby the consideration is not included in the transaction price and recognized in revenue until the customer’s subsequent sales or usages occur. Deferred Revenue When consideration is received or is unconditionally due from a customer, collaborator or licensee prior to the Company completing its performance obligation to the customer, collaborator or licensee under the terms of a contract, deferred revenue is recorded. Deferred revenue expected to be recognized as revenue within the 12 months following the balance sheet date is classified as a current liability. Deferred revenue not expected to be recognized as revenue within the 12 months following the balance sheet date is classified as a long-term liability. In accordance with ASC Topic 210-20, Balance Sheet - Offsetting (“ASC 210-20”) the Company’s deferred revenue is offset by a contract asset as further discussed in Note 9.
Segment information	Segment informationThe Company operates as a single segment.
Recent accounting pronouncements	Recent accounting pronouncements In June 2016, the Financial Accounting Standards Board issued Accounting Standards Update 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses in Financial Instruments (“ASC 326”). The guidance is effective for the Company beginning January 1, 2023 and it changes how entities account for credit losses on the financial assets and other instruments that are not measured at fair value through net income, including available-for-sale debt securities. The adoption of ASC 326 did not have a material impact on the consolidated financial statements. The Company has reviewed all other recently issued standards and has determined that such standards will not have a material impact on the Company’s financial statements or do not otherwise apply to the Company’s operations.
Fair value measurements	Fair value measurements The Company measures certain financial instruments and other items at fair value. To determine the fair value, the Company uses the fair value hierarchy for inputs used in measuring fair value that maximize the use of observable inputs and minimize the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs are inputs market participants would use to value an asset or liability and are developed based on market data obtained from independent sources. Unobservable inputs are inputs based on assumptions about the factors market participants would use to value an asset or liability. The three levels of inputs that may be used to measure fair value are as follows: • Level 1 inputs are quoted market prices for identical instruments available in active markets. • Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability either directly or indirectly. If the asset or liability has a contractual term, the input must be observable for substantially the full term. An example includes quoted market prices for similar assets or liabilities in active markets. • Level 3 inputs are unobservable inputs for the asset or liability and will reflect management’s assumptions about market assumptions that would be used to price the asset or liability. Assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurements. Changes in the observability of valuation inputs may result in a reclassification of levels for certain securities within the fair value hierarchy. The carrying values of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair values due to the immediate or short-term maturity of these financial instruments.

Fair Value Measures and Disclos

Fair Value Measures and Disclosures (Policies)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurements The Company measures certain financial instruments and other items at fair value. To determine the fair value, the Company uses the fair value hierarchy for inputs used in measuring fair value that maximize the use of observable inputs and minimize the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs are inputs market participants would use to value an asset or liability and are developed based on market data obtained from independent sources. Unobservable inputs are inputs based on assumptions about the factors market participants would use to value an asset or liability. The three levels of inputs that may be used to measure fair value are as follows: • Level 1 inputs are quoted market prices for identical instruments available in active markets. • Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability either directly or indirectly. If the asset or liability has a contractual term, the input must be observable for substantially the full term. An example includes quoted market prices for similar assets or liabilities in active markets. • Level 3 inputs are unobservable inputs for the asset or liability and will reflect management’s assumptions about market assumptions that would be used to price the asset or liability. Assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurements. Changes in the observability of valuation inputs may result in a reclassification of levels for certain securities within the fair value hierarchy. The carrying values of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair values due to the immediate or short-term maturity of these financial instruments.

Fair value measurements (Tables

Fair value measurements (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Assets and liabilities measured at fair value on a recurring basis	The following tables present information about the Company’s assets and liabilities that are measured at fair value on a recurring basis, and indicates the fair value hierarchy of the valuation techniques used to determine such fair value: Level 1 Level 2 Level 3 Total As of September 30, 2023 (in thousands) Assets Cash and cash equivalents $ 17,531 $ — $ — $ 17,531 Investments in marketable securities, current — 116,649 — 116,649 Investments in marketable securities, non-current — 10,496 — 10,496 Total $ 17,531 $ 127,145 $ — $ 144,676 Liabilities Contingent consideration — — 7,373 7,373 Total $ — $ — $ 7,373 $ 7,373 Level 1 Level 2 Level 3 Total As of December 31, 2022 (in thousands) Assets Cash and cash equivalents $ 30,776 $ — $ — $ 30,776 Investments in marketable securities, current — 116,137 — 116,137 Investments in marketable securities, non-current — 37,363 — 37,363 Total $ 30,776 $ 153,500 $ — $ 184,276 Liabilities Contingent consideration — — 7,531 7,531 Total $ — $ — $ 7,531 $ 7,531
Schedule of changes in fair value of contingent consideration	The following table presents the changes in fair value of the Company’s contingent consideration: Liability at beginning of the period Change in fair value of liability Liability at end of the period (in thousands) Nine Months Ended September 30, 2023 $ 7,531 $ (158) $ 7,373 Nine Months Ended September 30, 2022 $ 5,298 $ 624 $ 5,922

Investments in marketable sec_2

Investments in marketable securities (Tables)	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Marketable securities	Investments in marketable securities consisted of the following: Amortized Cost Gross Unrealized Gain (1) Gross Unrealized Loss (1) Fair Value As of September 30, 2023 (in thousands) Cash equivalents Money market $ 10,805 $ — $ — $ 10,805 Total $ 10,805 $ — $ — $ 10,805 Investments in marketable short-term securities US government agency bonds $ 31,706 $ — $ (158) $ 31,548 US corporate bonds 57,692 — (341) 57,351 US treasury bills 10,940 — (2) 10,938 Yankee bonds 2,000 — (32) 1,968 US government bonds 14,985 — (141) 14,844 Total $ 117,323 $ — $ (674) $ 116,649 Investments in marketable long-term securities US corporate bonds 10,522 — (29) 10,496 Total $ 10,522 $ 3 $ (29) $ 10,496 (1) Gross unrealized gain (loss) is pre-tax and is reported in accumulated other comprehensive loss. Amortized Cost Gross Unrealized Gain (1) Gross Unrealized Loss (1) Fair Value As of December 31, 2022 (in thousands) Cash equivalents Money market $ 23,218 $ — $ — $ 23,218 Total $ 23,218 $ — $ — $ 23,218 Investments in marketable short-term securities US government agency bonds $ 26,686 $ — $ (424) $ 26,262 US corporate bonds 27,144 — (303) 26,841 US treasury bills 8,483 — (16) 8,467 US government bonds $ 55,361 $ — $ (794) $ 54,567 Total $ 117,674 $ — $ (1,537) $ 116,137 Investments in marketable long-term securities US government agency bonds $ 3,724 $ — $ (130) $ 3,594 US treasury bills 25,433 — (336) 25,097 US government bonds 8,972 — (300) 8,672 Total $ 38,129 $ — $ (766) $ 37,363 (1) Gross unrealized gain (loss) is pre-tax and is reported in accumulated other comprehensive loss.

Accounts payable and accrued _2

Accounts payable and accrued liabilities (Tables)	9 Months Ended
	Sep. 30, 2023
Payables and Accruals [Abstract]
Schedule of accounts payable and accrued liabilities	Accounts payable and accrued liabilities are comprised of the following: September 30, 2023 December 31, 2022 (in thousands) Trade accounts payable $ 2,260 $ 3,520 Research and development accruals 4,210 8,261 Professional fee accruals 691 512 Payroll accruals 2,645 3,730 Other accrued liabilities — 6 Total accounts payable and accrued liabilities $ 9,806 $ 16,029

Sale of future royalties (Table

Sale of future royalties (Tables)	9 Months Ended
	Sep. 30, 2023
Other Liabilities Disclosure [Abstract]
Schedule of activity related to the net liability from inception of the Agreement	The table below shows the activity related to the net liability for the nine months ended September 30, 2023 and 2022: Nine Months Ended September 30, 2023 2022 (in thousands) Net liability related to sale of future royalties - beginning balance $ 10,365 $ 16,296 Non-cash royalty revenue (2,667) (5,393) Non-cash interest expense 412 1,413 Net liability related to sale of future royalties - ending balance $ 8,110 $ 12,316

Collaborations, contracts and_2

Collaborations, contracts and licensing agreements (Tables)	9 Months Ended
	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Schedule of deferred collaborations and contracts revenue	The following table outlines the transaction price and the changes to the related asset and liability balances during the nine months ended September 30, 2023: Nine Months Ended September 30, 2023 Transaction Price Cumulative Collaboration Revenue Recognized Deferred License Revenue (in thousands) Combined performance obligation $ 49,270 $ 36,364 $ 12,906 Less contract asset (800) Total deferred license revenue 12,106 Less current portion of deferred license revenue 12,106 Non-current deferred license revenue $ —
Summary of collaborations	Revenues are summarized in the following table: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands) (in thousands) Revenue from collaborations and licenses Acuitas Therapeutics, Inc. $ 714 $ 1,256 $ 2,980 $ 4,339 Qilu Pharmaceutical Co., Ltd. 3,221 2,352 10,349 23,007 Other milestone and royalty payments — — — 35 Non-cash royalty revenue Alnylam Pharmaceuticals, Inc. 723 2,344 2,667 5,393 Total revenue $ 4,658 $ 5,952 $ 15,996 $ 32,774

Shareholders_ equity (Tables)

Shareholders’ equity (Tables)	9 Months Ended
	Sep. 30, 2023
Stockholders' Equity Note [Abstract]
Schedule of stock based compensation expense	The table below summarizes information about the Company’s stock-based compensation for the three and nine months ended September 30, 2023 and 2022 and the expense recognized in the condensed consolidated statements of operations: Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 (in thousands, except share and per share data) Stock options Options granted during period 784,240 62,700 5,082,640 4,797,000 Weighted average exercise price $ 2.25 $ 2.37 $ 2.78 $ 2.77 Restricted stock units (“RSUs”) Restricted stock units granted during period — — 1,344,550 — Grant date fair value $ — $ — $ 2.90 $ — Stock compensation expense Research and development $ 1,002 $ 736 $ 2,854 $ 2,191 General and administrative 1,481 978 4,724 3,324 Total stock compensation expense $ 2,483 $ 1,714 $ 7,578 $ 5,515

Nature of business and future_2

Nature of business and future operations (Details)	Sep. 30, 2023 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash	$ 144,700,000
Long-term debt	$ 0

Significant accounting polici_3

Significant accounting policies (Details) shares in Millions	9 Months Ended
	Sep. 30, 2023 subsidiary shares	Sep. 30, 2022 shares
Accounting Policies [Abstract]
Number of wholly-owed subsidiaries | subsidiary	1
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Anti-dilutive common shares excluded from calculation of loss per common share (in shares)		15.9
Employee Stock Option
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Anti-dilutive common shares excluded from calculation of loss per common share (in shares)	21

Fair value measurements - Narra

Fair value measurements - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair value of contingent consideration	$ 7,373	$ 5,922	$ 7,531	$ 5,298
Increase (decrease) in fair value of contingent consideration	$ (158)	$ 624

Fair value measurements - Asset

Fair value measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
Assets
Investments in marketable securities, non-current	$ 10,496	$ 37,363
Liabilities
Contingent consideration	7,373	7,531	$ 5,922	$ 5,298
Recurring
Assets
Cash and cash equivalents	17,531	30,776
Investments in marketable securities, current	116,649	116,137
Investments in marketable securities, non-current	10,496	37,363
Total	144,676	184,276
Liabilities
Contingent consideration	7,373	7,531
Total	7,373	7,531
Recurring | Level 1
Assets
Cash and cash equivalents	17,531	30,776
Investments in marketable securities, current	0	0
Investments in marketable securities, non-current	0	0
Total	17,531	30,776
Liabilities
Contingent consideration	0	0
Total	0	0
Recurring | Level 2
Assets
Cash and cash equivalents	0	0
Investments in marketable securities, current	116,649	116,137
Investments in marketable securities, non-current	10,496	37,363
Total	127,145	153,500
Liabilities
Contingent consideration	0	0
Total	0	0
Recurring | Level 3
Assets
Cash and cash equivalents	0	0
Investments in marketable securities, current	0	0
Investments in marketable securities, non-current	0	0
Total	0	0
Liabilities
Contingent consideration	7,373	7,531
Total	$ 7,373	$ 7,531

Fair value measurements - Chang

Fair value measurements - Changes in Fair Value of Contingent Consideration (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Fair Value, Liabilities Measured on Recurring Basis [Roll Forward]
Liability at beginning of the period	$ 7,531	$ 5,298
Change in fair value of liability	(158)	624
Liability at end of the period	$ 7,373	$ 5,922

Investments in marketable sec_3

Investments in marketable securities - Marketable Securities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Debt Securities, Available-for-Sale [Abstract]
Accrued investment income receivable	$ 600		$ 600		$ 600
Realized gains or losses	100	$ 100	100	$ 100
Cash and Cash Equivalents
Cash and Cash Equivalents [Abstract]
Cash Equivalents, at Carrying Value	10,805		10,805		23,218
Cash Equivalents, Fair Value Disclosure	10,805		10,805		23,218
Short Term Marketable Securities
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	117,323		117,323		117,674
Gross Unrealized Gain	0		0		0
Gross Unrealized Loss	(674)		(674)		(1,537)
Fair Value	116,649		116,649		116,137
Long Term Marketable Securities
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	10,522		10,522		38,129
Gross Unrealized Gain	3		3		0
Gross Unrealized Loss	(29)		(29)		(766)
Fair Value	10,496		10,496		37,363
Money market | Cash and Cash Equivalents
Cash and Cash Equivalents [Abstract]
Money Market Funds, at Carrying Value	10,805		10,805		23,218
US treasury bills | Short Term Marketable Securities
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	10,940		10,940		8,483
Gross Unrealized Gain	0		0		0
Gross Unrealized Loss	(2)		(2)		(16)
Fair Value	10,938		10,938		8,467
US treasury bills | Long Term Marketable Securities
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost					25,433
Gross Unrealized Gain					0
Gross Unrealized Loss					(336)
Fair Value					25,097
US government agency bonds | Short Term Marketable Securities
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	31,706		31,706		26,686
Gross Unrealized Gain	0		0		0
Gross Unrealized Loss	(158)		(158)		(424)
Fair Value	31,548		31,548		26,262
US government agency bonds | Long Term Marketable Securities
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost					3,724
Gross Unrealized Gain					0
Gross Unrealized Loss					(130)
Fair Value					3,594
US corporate bonds | Short Term Marketable Securities
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	57,692		57,692		27,144
Gross Unrealized Gain	0		0		0
Gross Unrealized Loss	(341)		(341)		(303)
Fair Value	57,351		57,351		26,841
US corporate bonds | Long Term Marketable Securities
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	10,522		10,522
Gross Unrealized Gain	0		0
Gross Unrealized Loss	(29)		(29)
Fair Value	10,496		10,496
Yankee bonds | Short Term Marketable Securities
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	2,000		2,000
Gross Unrealized Gain	0		0
Gross Unrealized Loss	(32)		(32)
Fair Value	1,968		1,968
US government bonds | Short Term Marketable Securities
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	14,985		14,985		55,361
Gross Unrealized Gain	0		0		0
Gross Unrealized Loss	(141)		(141)		(794)
Fair Value	$ 14,844		$ 14,844		54,567
US government bonds | Long Term Marketable Securities
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost					8,972
Gross Unrealized Gain					0
Gross Unrealized Loss					(300)
Fair Value					$ 8,672

Investments in marketable sec_4

Investments in marketable securities - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) numberOfSegments	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) numberOfSegments	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) numberOfSegments
Investments, Debt and Equity Securities [Abstract]
Debt securities, available-for-sale, unrealized loss Position, number of positions | numberOfSegments	40		40		53
Accrued investment income receivable	$ 600		$ 600		$ 600
Realized gains or losses	$ 100	$ 100	$ 100	$ 100

Investment in Genevant (Details

Investment in Genevant (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)
Schedule of Equity Method Investments [Line Items]
Equity investment	$ 0
Genevant
Schedule of Equity Method Investments [Line Items]
Sub-licensing revenue percentage	20%
Bona fide collaboration Percentage	14%
Ownership interest in equity method investment (as a percentage)	16%

Accounts payable and accrued _3

Accounts payable and accrued liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Trade accounts payable	$ 2,260	$ 3,520
Research and development accruals	4,210	8,261
Professional fee accruals	691	512
Payroll accruals	2,645	3,730
Other accrued liabilities	0	6
Accounts payable and accrued liabilities	$ 9,806	$ 16,029

Sale of future royalties - Narr

Sale of future royalties - Narrative (Details) - USD ($) $ in Thousands			9 Months Ended		12 Months Ended	51 Months Ended
	Jul. 02, 2019	Jan. 01, 2019	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2014	Sep. 30, 2023
Other Liabilities Disclosure [Line Items]
Non-cash royalty revenue			$ 2,667	$ 5,393
Non-cash interest expense			$ 412	1,413
Minimum
Other Liabilities Disclosure [Line Items]
Royalty interest, % interest			0.75%
Maximum
Other Liabilities Disclosure [Line Items]
Royalty interest, % interest			1.125%
OMERS
Other Liabilities Disclosure [Line Items]
Gross proceeds from sale of royalty interest. before advisory fees		$ 20,000
Entitlement of royalties to be received	$ 30,000	30,000
Future royalty payments	30,000	$ 30,000
Transaction costs on sale of royalties	$ 1,500
Effective annual interest rate on royalty liability			2.30%
Non-cash royalty revenue			$ 2,700	5,400		$ 21,500
Non-cash interest expense			$ 400	$ 1,400
OMERS | Minimum
Other Liabilities Disclosure [Line Items]
Royalty interest, % interest	1%				1%
OMERS | Maximum
Other Liabilities Disclosure [Line Items]
Royalty interest, % interest	2.33%				2.33%

Sale of future royalties - Liab

Sale of future royalties - Liability Activity (Details) - USD ($) $ in Thousands		9 Months Ended		12 Months Ended
	Jul. 02, 2019	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2014
Liability Related To Sale Of Future Royalties [Roll Forward]
Net liability related to sale of future royalties - beginning balance		$ 10,365	$ 16,296
Non-cash royalty revenue		(2,667)	(5,393)
Non-cash interest expense		412	1,413
Net liability related to sale of future royalties - ending balance		8,110	$ 12,316
ONPATTRO
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty interest sold, annual revenue threshold of highest tier	$ 500,000	$ 500,000		$ 500,000

Contingencies and commitments (

Contingencies and commitments (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021	Oct. 31, 2014
Contingencies and Commitments [Line Items]
Fair value of contingent consideration	$ 7,373	$ 7,531	$ 5,922	$ 5,298
Recurring
Contingencies and Commitments [Line Items]
Fair value of contingent consideration	7,373	$ 7,531
Enantigen's Selling Shareholders | Recurring
Contingencies and Commitments [Line Items]
Fair value of contingent consideration	$ 7,400				$ 0
Enantigen's Selling Shareholders | Arbutus Inc.
Contingencies and Commitments [Line Items]
Development and regulatory milestones payment per licensed compound series, maximum					102,500
Development and regulatory milestones payment per royalty, maximum					$ 1,000

Collaborations, contracts and_3

Collaborations, contracts and licensing agreements (Details) $ / shares in Units, $ in Thousands					3 Months Ended			9 Months Ended		12 Months Ended	51 Months Ended
	Jan. 06, 2022 USD ($)	Jan. 05, 2022 USD ($)	Jul. 02, 2019 USD ($)	Jan. 01, 2019 USD ($)	Sep. 30, 2023 USD ($) product shares	Mar. 31, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) product shares	Sep. 30, 2022 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2023 USD ($) product shares	Dec. 31, 2022 USD ($) shares	Dec. 13, 2021 USD ($) $ / shares shares
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Common shares, shares issued (in shares) | shares					167,695,247			167,695,247			167,695,247	157,455,363
Premiums earned, net								$ 4,100
Deferred license revenue, current					$ 12,106			12,106			$ 12,106	$ 16,456
Deferred license revenue, non-current					0			0			0	$ 5,999
Revenues					4,658		$ 5,952	15,996	$ 32,774
Total deferred license revenue					$ 12,106			$ 12,106			$ 12,106
Number of royalty entitlements | product					2			2			2
Non Cash Royalty Revenue Related To Sale Of Future Royalties								$ 2,667	5,393
Qilu Pharmaceutical Co, LTD.
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Income taxes paid						$ 4,400		4,400
Deferred license revenue, non-current					$ 0			0			$ 0
Common Shares | Qilu Pharmaceutical Co, LTD.
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Noncontrolling interest, ownership percentage by noncontrolling owners													2.50%
Non-cash royalty revenue
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenues					723		2,345	$ 2,667	5,393
Minimum
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty interest, % interest								0.75%
Maximum
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty interest, % interest								1.125%
Assembly Biosciences, Inc.
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Costs related to collaboration					100		600	$ 1,400	2,100
Vaccitech
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Costs related to collaboration					700		300	1,600	700
OMERS
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Gross proceeds from sale of royalty interest. before advisory fees				$ 20,000
Entitlement of royalties to be received			$ 30,000	30,000
Future royalty payments			$ 30,000	$ 30,000
Non Cash Royalty Revenue Related To Sale Of Future Royalties								2,700	5,400		21,500
OMERS | Minimum
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty interest, % interest			1%							1%
OMERS | Maximum
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty interest, % interest			2.33%							2.33%
Arbutus Biopharma Corp
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty guarantees commitments percentage			100%	100%
Acuitas Therapeutics, Inc. | Revenue from collaborations and licenses
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenues					714		1,256	2,980	4,339
Other milestone and royalty payments | Revenue from collaborations and licenses
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenues					0		0	0	35
Alnylam Pharmaceuticals, Inc. | Non-cash royalty revenue
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenues					723		2,344	2,667	5,393
Qilu Pharmaceutical Co, LTD.
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential milestone payments													$ 245,000
Revenue, remaining performance obligation, amount					12,906			12,906			12,906		49,270
Recovery of direct costs								(800)
Cumulative Collaboration Revenue Recognized								36,364
Deferred license revenue, current					12,106			12,106			12,106
Total deferred license revenue					12,100			12,100			$ 12,100
Other deferred costs, gross													$ 600
Amortization of other deferred charges					100		100	100	300
Qilu Pharmaceutical Co, LTD. | Common Shares
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Common shares, shares issued (in shares) | shares													3,579,952
Share price (in USD per share) | $ / shares													$ 4.19
Premium on closing stock price (as a percent)													15%
Issuance of common shares pursuant to the Open Market Sale Agreement	$ 15,000
Qilu Pharmaceutical Co, LTD. | One-Time Upfront Cash Payment
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Proceeds from collaborators		$ 40,000
Qilu Pharmaceutical Co, LTD. | Revenue from collaborations and licenses
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenues					3,221		2,352	10,349	23,007
X-Chem, Inc. and Proteros
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Costs related to collaboration					$ 100		$ 600	1,000	$ 900
ONPATTRO
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty interest sold, annual revenue threshold of highest tier			$ 500,000					$ 500,000		$ 500,000

Shareholders_ equity - Narrativ

Shareholders’ equity - Narrative (Details) - USD ($) $ in Millions

3 Months Ended

9 Months Ended

Sep. 30, 2023

Sep. 30, 2022

Sep. 30, 2023

Sep. 30, 2022

Oct. 22, 2023

Mar. 03, 2022

Nov. 04, 2021

Oct. 08, 2021

Mar. 04, 2021

Oct. 22, 2020

Aug. 07, 2020

Jan. 10, 2020

Class of Stock [Line Items]

Preferred stock, shares authorized (in shares)

1,164,000

1,164,000

Common Shares | Jan 2020 Registration Stmt

Class of Stock [Line Items]

Aggregate sale price of common shares under agreement

$ 150

Common Shares | Oct 2020 Registration Stmt

Class of Stock [Line Items]

Aggregate sale price of common shares under agreement

$ 200

Common Shares | Nov 2021 Registration Stmt

Class of Stock [Line Items]

Aggregate sale price of common shares under agreement

$ 250

Common Shares | March 2022 Prospectus Supplement | November 2021 Registration Statement [Member]

Class of Stock [Line Items]

Aggregate sale price of common shares under agreement

$ 75

Jefferies LLC | Common Shares | Sale Agreement

Class of Stock [Line Items]

Number of shares issued under agreement (in sales)

633,922

3,832,717

9,848,090

3,832,717

Proceeds from issuance of shares under the agreement

$ 1.4

$ 9

$ 26

$ 9

Jefferies LLC | Common Shares | Mar 2021 Prospectus Supplement Agreement | Oct 2020 Registration Stmt

Class of Stock [Line Items]

Aggregate sale price of common shares under agreement

$ 75

Jefferies LLC | Common Shares | October 2021 Prospectus Supplement

Class of Stock [Line Items]

Aggregate sale price of common shares under agreement

104.3

104.3

Jefferies LLC | Common Shares | October 2021 Prospectus Supplement | Oct 2020 Registration Stmt

Class of Stock [Line Items]

Aggregate sale price of common shares under agreement

$ 75

Jefferies LLC | Common Shares | October 2021 Prospectus Supplement | Oct 2020 Registration Stmt | Subsequent Event

Class of Stock [Line Items]

Common Stock, Value, Subscriptions Expired

$ 29.3

Jefferies LLC | Common Shares | March 2022 Prospectus Supplement

Class of Stock [Line Items]

Aggregate sale price of common shares under agreement

$ 104.3

$ 104.3

Jefferies LLC | Common Shares | March 2022 Prospectus Supplement | Jan 2020 Oct 2020 and Nov 2021 Registration Stmts

Class of Stock [Line Items]

Aggregate sale price of common shares under agreement

$ 100

Jefferies LLC | Common Shares | Jan 2020 Prospectus Supplement | Jan 2020 Registration Stmt

Class of Stock [Line Items]

Aggregate sale price of common shares under agreement

$ 50

Jefferies LLC | Common Shares | Aug 2020 Prospectus Supplement | Jan 2020 Registration Stmt

Class of Stock [Line Items]

Aggregate sale price of common shares under agreement

$ 75

Shareholders_ equity - Stock-ba

Shareholders’ equity - Stock-based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average exercise price (in USD per share)	$ 2.25	$ 2.37	$ 2.78	$ 2.77
Restricted stock units granted during period (in shares)	0		1,344,550	0
Grant date fair value (in USD per share)	$ 2.90	$ 0	$ 2.90	$ 0
Allocated share-based compensation expense	$ 2,483	$ 1,714	$ 7,578	$ 5,515
Share-based compensation arrangement by share-based payment award, award vesting period			3 years
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense	1,002	736	$ 2,854	2,191
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense	$ 1,481	$ 978	$ 4,724	$ 3,324
Arbutus Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted during period (in shares)	784,240	62,700	5,082,640	4,797,000

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event - USD ($) $ in Thousands		3 Months Ended
	Nov. 06, 2023	Dec. 31, 2023
Subsequent Event [Line Items]
Restructuring and related cost, number of positions eliminated, percent	24%
Restructuring charges		$ 1,100