Kiniksa Pharmaceuticals (KNSA) 10-Q 3 Nov 22 2022 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Oct. 31, 2022
Document information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2022
Entity File Number	001-38492
Entity Registrant Name	Kiniksa Pharmaceuticals, Ltd.
Entity Incorporation, State or Country Code	D0
Entity Tax Identification Number	98-1327726
Entity Address, Address Line One	Clarendon House
Entity Address, Address Line Two	2 Church Street
Entity Address, City or Town	Hamilton
Entity Address, Country	BM
Entity Address, Postal Zip Code	HM11
City Area Code	808
Local Phone Number	451-3453
Title of 12(b) Security	Class A Common Shares
Trading Symbol	KNSA
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
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001730430
Amendment Flag	false
Common Shares
Document information
Entity Common Stock, Shares Outstanding		69,531,762
Class A common shares
Document information
Entity Common Stock, Shares Outstanding		34,531,084
Class B common shares
Document information
Entity Common Stock, Shares Outstanding		1,813,457
Class A1 common shares
Document information
Entity Common Stock, Shares Outstanding		17,129,603
Class B1 common shares
Document information
Entity Common Stock, Shares Outstanding		16,057,618

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 175,761	$ 122,470
Short-term investments	24,963	59,731
Accounts receivable, net	11,159	3,985
Inventory	14,621	3,675
Prepaid expenses and other current assets	15,311	6,585
Total current assets	241,815	196,446
Property and equipment, net	1,995	2,834
Operating lease right-of-use assets	6,173	5,550
Other long-term assets	5,627	8,720
Intangible asset, net	18,500	19,250
Deferred tax assets	185,843
Total assets	459,953	232,800
Current liabilities:
Accounts payable	1,469	1,868
Accrued expenses	30,868	38,031
Deferred revenue	12,092
Operating lease liabilities	3,274	3,381
Other current liabilities	8,789	1,544
Total current liabilities	56,492	44,824
Non-current liabilities:
Non-current deferred revenue	14,198
Non-current operating lease liabilities	3,435	2,669
Other long-term liabilities	1,820	270
Total liabilities	75,945	47,763
Commitments and contingencies (Note 14)
Shareholders' equity:
Additional paid-in capital	880,554	860,482
Accumulated other comprehensive loss	(70)	(66)
Accumulated deficit	(496,495)	(675,397)
Total shareholders' equity	384,008	185,037
Total liabilities and shareholders' equity	459,953	232,800
Class A common shares
Shareholders' equity:
Common stock value	9	8
Class B common shares
Shareholders' equity:
Common stock value	1	1
Class A1 common shares
Shareholders' equity:
Common stock value	5	5
Class B1 common shares
Shareholders' equity:
Common stock value	$ 4	$ 4

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2022	Dec. 31, 2021
Class A common shares
Common stock, par value (in dollars per share)	$ 0.000273235	$ 0.000273235
Common stock, shares issued (in shares)	34,523,660	34,059,725
Common stock, shares outstanding (in shares)	34,523,660	34,059,725
Class B common shares
Common stock, par value (in dollars per share)	$ 0.000273235	$ 0.000273235
Common stock, shares issued (in shares)	1,813,457	1,813,457
Common stock, shares outstanding (in shares)	1,813,457	1,813,457
Class A1 common shares
Common stock, par value (in dollars per share)	$ 0.000273235	$ 0.000273235
Common stock, shares issued (in shares)	17,129,603	17,129,603
Common stock, shares outstanding (in shares)	17,129,603	17,129,603
Class B1 common shares
Common stock, par value (in dollars per share)	$ 0.000273235	$ 0.000273235
Common stock, shares issued (in shares)	16,057,618	16,057,618
Common stock, shares outstanding (in shares)	16,057,618	16,057,618

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenue:
Product revenue, net	$ 99,135	$ 12,095	$ 158,296	$ 19,799
Costs and operating expenses:
Research and development	16,485	19,236	51,100	71,864
Selling, general and administrative	24,677	20,759	70,736	63,207
Total operating expenses	52,722	42,762	154,570	140,304
Income (loss) from operations	46,413	(30,667)	3,726	(120,505)
Interest income	322	5	459	20
Income (loss) before income taxes	46,735	(30,662)	4,185	(120,485)
(Provision) benefit for income taxes	177,358	118	174,717	(1,106)
Net income (loss)	$ 224,093	$ (30,544)	$ 178,902	$ (121,591)
Net income (loss) per share attributable to common shareholders, basic	$ 3.23	$ (0.44)	$ 2.58	$ (1.78)
Net income (loss) per share attributable to common shareholders, diluted	$ 3.18	$ (0.44)	$ 2.55	$ (1.78)
Weighted average common shares outstanding, basic	69,445,071	68,662,673	69,305,755	68,444,061
Weighted average common shares outstanding, diluted	70,552,018	68,662,673	70,286,444	68,444,061
Comprehensive income (loss):
Net income (loss)	$ 224,093	$ (30,544)	$ 178,902	$ (121,591)
Other comprehensive income (loss):
Unrealized gain (loss) on short-term investments and currency translation adjustments, net of tax	20	(72)	(4)	(11)
Total other comprehensive income (loss)	20	(72)	(4)	(11)
Total comprehensive income (loss)	224,113	(30,616)	178,898	(121,602)
Product revenue, net
Revenue:
Product revenue, net	33,424	12,095	82,585	19,799
Costs and operating expenses:
Cost of goods sold	6,937	$ 2,767	16,185	$ 5,233
License and collaboration revenue
Revenue:
Product revenue, net	65,711		75,711
Costs and operating expenses:
Cost of goods sold	$ 4,623		$ 16,549

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Common Shares	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Total
Balance at the beginning of the period at Dec. 31, 2020	$ 18	$ 829,424	$ (34)	$ (517,473)	$ 311,935
Balance at the beginning of the period (in shares) at Dec. 31, 2020	68,215,022
Changes in equity
Issuance of Class A common shares under incentive award plans		1,106			1,106
Issuance of Class A common shares under incentive award plans (in shares)	115,012
Share-based compensation expense		7,126			7,126
Unrealized gain on short-term investments and currency translation adjustments			13		13
Net income (loss)				(49,484)	(49,484)
Balance at the end of the period at Mar. 31, 2021	$ 18	837,656	(21)	(566,957)	270,696
Balance at the end of the period (in shares) at Mar. 31, 2021	68,330,034
Balance at the beginning of the period at Dec. 31, 2020	$ 18	829,424	(34)	(517,473)	311,935
Balance at the beginning of the period (in shares) at Dec. 31, 2020	68,215,022
Changes in equity
Unrealized gain on short-term investments and currency translation adjustments					(11)
Net income (loss)					(121,591)
Balance at the end of the period at Sep. 30, 2021	$ 18	853,139	(45)	(639,064)	214,048
Balance at the end of the period (in shares) at Sep. 30, 2021	68,888,435
Balance at the beginning of the period at Mar. 31, 2021	$ 18	837,656	(21)	(566,957)	270,696
Balance at the beginning of the period (in shares) at Mar. 31, 2021	68,330,034
Changes in equity
Issuance of Class A common shares under incentive award plans		887			887
Issuance of Class A common shares under incentive award plans (in shares)	134,715
Share-based compensation expense		5,717			5,717
Unrealized gain on short-term investments and currency translation adjustments			48		48
Net income (loss)				(41,563)	(41,563)
Balance at the end of the period at Jun. 30, 2021	$ 18	844,260	27	(608,520)	235,785
Balance at the end of the period (in shares) at Jun. 30, 2021	68,464,749
Changes in equity
Issuance of Class A common shares under incentive award plans		2,680			2,680
Issuance of Class A common shares under incentive award plans (in shares)	423,686
Share-based compensation expense		6,199			6,199
Unrealized gain on short-term investments and currency translation adjustments			(72)		(72)
Net income (loss)				(30,544)	(30,544)
Balance at the end of the period at Sep. 30, 2021	$ 18	853,139	(45)	(639,064)	214,048
Balance at the end of the period (in shares) at Sep. 30, 2021	68,888,435
Balance at the beginning of the period at Dec. 31, 2021	$ 18	860,482	(66)	(675,397)	185,037
Balance at the beginning of the period (in shares) at Dec. 31, 2021	69,060,403
Changes in equity
Issuance of Class A common shares under incentive award plans	$ 1	422			423
Issuance of Class A common shares under incentive award plans (in shares)	210,720
Share-based compensation expense		6,031			6,031
Unrealized gain on short-term investments and currency translation adjustments			(37)		(37)
Net income (loss)				(25,210)	(25,210)
Balance at the end of the period at Mar. 31, 2022	$ 19	866,935	(103)	(700,607)	166,244
Balance at the end of the period (in shares) at Mar. 31, 2022	69,271,123
Balance at the beginning of the period at Dec. 31, 2021	$ 18	860,482	(66)	(675,397)	185,037
Balance at the beginning of the period (in shares) at Dec. 31, 2021	69,060,403
Changes in equity
Unrealized gain on short-term investments and currency translation adjustments					(4)
Net income (loss)					178,902
Balance at the end of the period at Sep. 30, 2022	$ 19	880,554	(70)	(496,495)	384,008
Balance at the end of the period (in shares) at Sep. 30, 2022	69,524,338
Balance at the beginning of the period at Mar. 31, 2022	$ 19	866,935	(103)	(700,607)	166,244
Balance at the beginning of the period (in shares) at Mar. 31, 2022	69,271,123
Changes in equity
Issuance of Class A common shares under incentive award plans		542			542
Issuance of Class A common shares under incentive award plans (in shares)	155,644
Share-based compensation expense		6,676			6,676
Unrealized gain on short-term investments and currency translation adjustments			13		13
Net income (loss)				(19,981)	(19,981)
Balance at the end of the period at Jun. 30, 2022	$ 19	874,153	(90)	(720,588)	153,494
Balance at the end of the period (in shares) at Jun. 30, 2022	69,426,767
Changes in equity
Issuance of Class A common shares under incentive award plans		360			360
Issuance of Class A common shares under incentive award plans (in shares)	97,571
Share-based compensation expense		6,041			6,041
Unrealized gain on short-term investments and currency translation adjustments			20		20
Net income (loss)				224,093	224,093
Balance at the end of the period at Sep. 30, 2022	$ 19	$ 880,554	$ (70)	$ (496,495)	$ 384,008
Balance at the end of the period (in shares) at Sep. 30, 2022	69,524,338

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities:
Net income (loss)	$ 178,902	$ (121,591)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	1,800	1,687
Share-based compensation expense	18,748	19,042
Non-cash lease expense	2,253	1,895
Amortization of premiums and accretion of discounts on short-term investments	121	617
Loss on disposal of property and equipment	23
Deferred income taxes	(185,843)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(8,726)	1,034
Accounts receivable, net	(7,174)	(3,224)
Inventory	(10,946)	(5,606)
Other long-term assets	2,919	(1,059)
Accounts payable	(399)	1,116
Accrued expenses and other current liabilities	82	295
Operating lease liabilities	(2,217)	(1,700)
Deferred revenue	26,290
Other long-term liabilities	1,550	80
Net cash provided (used) in operating activities	17,383	(107,414)
Cash flows from investing activities:
Proceeds from sale of property and equipment	81
Purchases of property and equipment	(137)	(164)
Purchases of short-term investments	(73,062)	(97,460)
Proceeds from the maturities of short-term investments	107,700	296,300
Intangible asset acquired		(20,000)
Net cash provided by investing activities	34,582	178,676
Cash flows from financing activities:
Proceeds from issuance of Class A common shares under incentive award plans and employee share purchase plans	2,127	4,673
Payments in connection with Common Stock tendered for employee tax obligations	(801)
Net cash provided by financing activities	1,326	4,673
Net increase in cash, cash equivalents and restricted cash	53,291	75,935
Cash, cash equivalents and restricted cash at beginning of period	122,470	114,248
Cash, cash equivalents and restricted cash at end of period	175,761	190,183
Supplemental information:
Cash paid for income taxes	4,608	859
Supplemental disclosure of non-cash investing and financing activities:
Right-of-use asset obtained in exchange for operating lease obligation	$ 2,876	$ 1,462

Nature of the Business and Basi

Nature of the Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2022
Nature of the Business and Basis of Presentation
Nature of the Business and Basis of Presentation	1. Nature of the Business and Basis of Presentation Kiniksa Pharmaceuticals, Ltd. (the “Company”) is a biopharmaceutical company focused on discovering, acquiring, developing and commercializing therapeutic medicines for patients suffering from debilitating diseases with significant unmet medical need. The Company’s portfolio of assets is based on strong biologic rationale or validated mechanisms, target underserved conditions and offer the potential for differentiation. The Company is subject to risks and uncertainties common to early, commercial stage companies in the biopharmaceutical industry and global health, societal, economic and market conditions, including the Company’s dependence on third parties, including contract research organizations and contract manufacturing organizations, the Company’s limited experience obtaining regulatory approvals, the potential failure of the Company to successfully complete research and development of its current or future product candidates, the potential inability of the Company to adequately protect its technology, potential competition, the uncertainty that any current or future product candidates will obtain necessary government regulatory approval, that ARCALYST will continue to be commercially viable, whether any of the Company’s current or future product candidates, if approved, will be commercially viable, adverse impact from the coronavirus disease 2019 (“COVID-19”) pandemic and global and political turmoil, including the ongoing war in Ukraine. Such risks and uncertainties, especially those risks and uncertainties arising from the ongoing COVID-19 pandemic, may be subject to substantial and uncertain changes, which may cause significant disruption to the Company’s business and operations, preclinical studies and clinical trials, the business and operations of the third parties with whom the Company conducts business and the national and global economies, all of which may have material impacts on the Company’s business, financial condition and results of operations. Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and include the accounts of the Company and its wholly owned subsidiaries, Kiniksa Pharmaceuticals Corp. (“Kiniksa US”), Primatope Therapeutics, Inc. (“Primatope”) and Kiniksa Pharmaceuticals (UK), Ltd. (“Kiniksa UK”) as well as the subsidiaries of Kiniksa UK, Kiniksa Pharmaceuticals (Germany) GmbH (“Kiniksa Germany”), Kiniksa Pharmaceuticals (France) SARL (“Kiniksa France”), and Kiniksa Pharmaceuticals GmbH (“Kiniksa Switzerland”), after elimination of all significant intercompany accounts and transactions. Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the recognition of revenue, the capitalization of inventory, the accrual for research and development expenses, the valuation of share-based awards and the realizability of deferred tax assets. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from those estimates. Unaudited Interim Consolidated Financial Information The accompanying unaudited consolidated financial statements have been prepared in accordance with GAAP for interim financial information. The accompanying unaudited consolidated financial statements do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. The information included in this quarterly report on Form 10-Q should be read in conjunction with the Company’s audited consolidated financial statements and the accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021 (the “2021 Form 10-K”). The Company’s accounting policies are described in the Notes to Consolidated Financial Statements in the Company’s 2021 Form 10-K and updated, as necessary, in this report. The accompanying year-end consolidated balance sheet was derived from audited financial statements but does not include all disclosures required by GAAP. The unaudited interim consolidated financial statements have been prepared on the same basis as the audited annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of September 30, 2022 and the results of its operations for the three and nine months ended September 30, 2022 and 2021, the changes in its shareholders’ equity for the three and nine months ended September 30, 2022 and 2021 and its cash flows for the nine months ended September 30, 2022 and 2021. The results for the three and nine months ended September 30, 2022 are not necessarily indicative of results to be expected for the year ending December 31, 2022, any other interim periods or any future year or period. Liquidity The Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date the consolidated financial statements are issued. As of September 30, 2022, the Company had an accumulated deficit of $496,495. During the nine months ended September 30, 2022, the Company reported net income of $178,902 and provided $17,383 cash in operating activities. As of September 30, 2022, the Company had cash, cash equivalents and short-term investments of $200,724. Based on its current operating plan, the Company expects that its cash, cash equivalents and short-term investments will be sufficient to fund its operations and capital expenditure requirements for at least twelve months from the issuance date of these consolidated financial statements. The future viability of the Company beyond that point is dependent on its ability to fund its operations through sales of ARCALYST and/or raise additional capital, as needed. If the Company is unable to grow sales of ARCALYST in future periods, the Company would need to seek additional financing through public or private securities offerings, debt financings, government funding or grants, or other sources, which may include licensing, collaborations or other strategic transactions or arrangements. Although the Company has been successful in raising capital in the past, there is no assurance that it will be successful in obtaining such additional financing on terms acceptable to the Company, if at all. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate some or all of its commercialization efforts, research and development programs for product candidates or product portfolio expansion, which could adversely affect its business prospects, or the Company may be unable to continue operations. ​ ​

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2022
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Revenue Recognition ​ ASC Topic 606, Revenue from Contracts with Customers (“ASC 606”) outlines a five-step process for recognizing revenue from contracts with customers: (i) identify the contract with the customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the separate performance obligations in the contract, and (v) recognize revenue associated with the performance obligations as they are satisfied. ​ The Company only applies the five-step model to contracts when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. Once a contract is determined to be within the scope of ASC 606, the Company determines the performance obligations that are distinct. The Company recognizes as revenues the amount of the transaction price that is allocated to each respective performance obligation when the performance obligation is satisfied. Generally, the Company’s performance obligations are transferred to customers at a point in time, typically upon delivery of the product to the customer. ​ ASC 606 requires entities to record a contract asset when a performance obligation has been satisfied or partially satisfied, but the amount of consideration has not yet been received because the receipt of the consideration is conditioned on something other than the passage of time. ASC 606 also requires an entity to present a revenue contract as a contract liability in instances when a customer pays consideration, or an entity has a right to an amount of consideration that is unconditional (e.g., receivable), before the entity transfers a good or service to the customer. Collaboration Revenue The Company analyzes its collaboration arrangements to assess whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities and therefore within the scope of ASC Topic 808, Collaborative Arrangements (“Topic 808”). This assessment is performed throughout the life of the arrangement based on changes in the responsibilities of all parties in the arrangement. For collaboration arrangements within the scope of Topic 808 that contain multiple elements, the Company first determines which elements of the collaboration are deemed to be within the scope of Topic 808 and which elements of the collaboration are more reflective of a vendor-customer relationship and therefore within the scope of Topic 606. For elements of collaboration arrangements that are accounted for pursuant to ASC 606, we identify the performance obligations and allocate the total consideration we expect to receive on a relative standalone selling price basis to each performance obligation. Variable consideration such as performance-based milestones will be included in the total consideration if we expect to receive such consideration and if it is probable that the inclusion of the variable consideration will not result in a significant reversal in the cumulative amount of revenue recognized under the arrangement. Our estimate of the total consideration we expect to receive under each collaboration arrangement is updated for each reporting period, and any adjustments to revenue are recorded on a cumulative catch-up basis. We exclude sales-based royalty and milestone payments from the total consideration we expect to receive until the underlying sales occur because the license to our intellectual property is deemed to be the predominant item to which the royalties or milestones relate as it is the primary driver of value in our collaboration arrangements. Key assumptions to determine the standalone selling price may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success. We recognize revenue associated with each performance obligation as the control over the promised goods or services transfer to our collaboration partner which occurs either at a point in time or over time. If control transfers over time, revenue is recognized by using a method of measuring progress that best depicts the transfer of goods or services. We evaluate the measure of progress and related inputs each reporting period and any resulting adjustments to revenue are recorded on a cumulative catch-up basis. Consideration received that does not meet the requirements to satisfy ASC 808 or ASC 606 revenue recognition criteria is recorded as deferred revenue in the accompanying consolidated balance sheets, classified as either short-term (less than 12 months) or long-term (more than 12 months) deferred revenue based on our best estimate of when such revenue will be recognized. There have been no other material changes to the significant accounting policies previously disclosed in the Company’s 2021 Form 10-K. Recently Adopted Accounting Pronouncements ​ ​

Fair Value of Financial Assets

Fair Value of Financial Assets and Liabilities	9 Months Ended
	Sep. 30, 2022
Fair Value of Financial Assets and Liabilities
Fair Value of Financial Assets and Liabilities	3. Fair Value of Financial Assets and Liabilities Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: ● Level 1—Quoted prices in active markets for identical assets or liabilities. ● Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. ● Level 3—Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The following tables present information about the Company’s financial instruments measured at fair value on a recurring basis and indicate the level of the fair value hierarchy used to determine such fair values: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ as of September 30, 2022 Using: ​ Level 1 Level 2 Level 3 Total Assets: ​ ​ ​ ​ Cash equivalents — money market funds ​ $ 39,533 ​ $ — ​ $ — ​ $ 39,533 Short-term investments — U.S. Treasury notes ​ ​ — ​ ​ 24,963 ​ ​ — ​ ​ 24,963 ​ ​ $ 39,533 ​ $ 24,963 ​ $ — ​ $ 64,496 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ as of December 31, 2021 Using: ​ Level 1 Level 2 Level 3 Total Assets: ​ ​ ​ ​ Cash equivalents — money market funds ​ $ 94,324 ​ $ — ​ $ — ​ $ 94,324 Short-term investments — U.S. Treasury notes ​ ​ — ​ ​ 59,731 ​ ​ — ​ ​ 59,731 ​ ​ $ 94,324 ​ $ 59,731 ​ $ — ​ $ 154,055 ​ During the nine months ended September 30, 2022 and the year ended December 31, 2021 there were no transfers between Level 1, Level 2 and Level 3. The money market funds were valued using quoted prices in active markets, which represent a Level 1 measurement in the fair value hierarchy. The Company’s cash equivalents and short-term investments as of September 30, 2022 and December 31, 2021 included U.S. Treasury notes, which are not traded on a daily basis and, therefore, represent a Level 2 measurement in the fair value hierarchy at each period end. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Credit ​ Fair ​ ​ Cost ​ Gains ​ Losses ​ Losses ​ Value September 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Short-term investments — U.S. Treasury notes ​ $ 24,986 ​ $ — ​ $ (23) ​ $ — ​ $ 24,963 ​ ​ $ 24,986 ​ $ — ​ $ (23) ​ $ — ​ $ 24,963 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Credit ​ Fair ​ ​ Cost ​ Gains ​ Losses ​ Losses ​ Value December 31, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Short-term investments — U.S. Treasury notes ​ $ 59,745 ​ $ 1 ​ $ (15) ​ $ — ​ $ 59,731 ​ ​ $ 59,745 ​ $ 1 ​ $ (15) ​ $ — ​ $ 59,731 ​ As of September 30, 2022, the Company held 6 securities that were in an unrealized loss position. The aggregate fair value of securities held by the Company in an unrealized loss position was $22,466 at September 30, 2022. As of December 31, 2021, the Company held 11 securities that were in an unrealized loss position. The aggregate fair value of securities held by the Company in an unrealized loss position was $49,739 at December 31, 2021. As of September 30, 2022 and December 31, 2021, these securities were held by the Company in an unrealized loss position for less than 12 months. The Company determined that there was no material change in the credit risk of these securities. As a result, the Company determined it did not hold any investments with an other-than-temporary impairment as of September 30, 2022 and December 31, 2021.

Product Revenue, Net

Product Revenue, Net	9 Months Ended
	Sep. 30, 2022
Product Revenue, Net
Product Revenue, Net	4. Product Revenue, Net ARCALYST ​ Following the approval by the U.S. Food and Drug Administration (“FDA”) of ARCALYST on March 18, 2021, the Company began generating product revenue from sales of ARCALYST in April 2021. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ ​ 2022 ​ 2021 ​ 2022 ​ 2021 Product revenue, net ​ $ 33,424 ​ $ 12,095 ​ $ 82,585 ​ $ 19,799 ​ The following table summarizes balances and activity in each of the product revenue allowance and reserve categories for the nine months ended September 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contractual ​ Government ​ ​ ​ ​ ​ ​ Adjustments ​ Rebates ​ Returns ​ Total Balance at December 31, 2021 ​ $ 515 ​ $ 719 ​ $ 101 ​ $ 1,335 Current provisions relating to sales in the current year ​ ​ 4,993 ​ ​ 3,011 ​ ​ 227 ​ ​ 8,231 Payments/returns relating to sales in the current year ​ ​ (3,797) ​ ​ (1,659) ​ ​ — ​ ​ (5,456) Payments/returns relating to sales in the prior years ​ ​ (295) ​ ​ (535) ​ ​ — ​ ​ (830) Balance at September 30, 2022 ​ $ 1,416 ​ $ 1,536 ​ $ 328 ​ $ 3,280 ​ ​ ​ ​ ​ ​ Total revenue-related reserves as of September 30, 2022 and December 31, 2021, included in our consolidated balance sheets, are summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2022 ​ 2021 Reduction of accounts receivable ​ $ (157) ​ $ (50) Components of other current liabilities ​ ​ 3,437 ​ ​ 1385 Total revenue-related reserves ​ $ 3,280 ​ $ 1,335 ​

Inventory

Inventory	9 Months Ended
	Sep. 30, 2022
Inventory
Inventory	5. Inventory Inventory consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2022 2021 Raw materials ​ $ — ​ $ — Work-in-process ​ — ​ — Finished Goods ​ ​ 14,621 ​ ​ 3,675 ​ ​ $ 14,621 ​ $ 3,675 ​

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2022
Property and Equipment, Net
Property and Equipment, Net	6. Property and Equipment, Net Property and equipment, net consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2022 2021 Furniture, fixtures and vehicles ​ $ 224 ​ $ 62 Computer hardware and software ​ 345 ​ 341 Leasehold improvements ​ ​ 3,931 ​ ​ 3,931 Lab equipment ​ ​ 4,068 ​ ​ 4,249 Construction in progress ​ 32 ​ 166 Total property and equipment ​ ​ 8,600 ​ ​ 8,749 Less: Accumulated depreciation ​ (6,605) ​ (5,915) Total property and equipment, net ​ $ 1,995 ​ $ 2,834 ​ Depreciation expense was $177 and $373 during the three months ended September 30, 2022 and 2021, respectively, and $885 and $1,079 during the nine months ended September 30, 2022 and 2021, respectively.

Intangible Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2022
Intangible Assets
Intangible Assets	7. Intangible Assets Intangible assets, net of accumulated amortization, impairment charges and adjustments as of September 30, 2022 and December 31, 2021 are summarized in the following table. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, 2022 ​ As of December 31, 2021 ​ ​ Estimated ​ ​ ​ Accumulated ​ ​ ​ ​ ​ Accumulated ​ ​ ​ life Cost Amortization Net ​ Cost Amortization Net Regulatory milestone ​ 20 years ​ $ 20,000 ​ $ 1,500 ​ $ 18,500 ​ $ 20,000 ​ $ 750 ​ $ 19,250 ​ ​ ​ ​ $ 20,000 ​ $ 1,500 ​ $ 18,500 ​ $ 20,000 ​ $ 750 ​ $ 19,250 ​

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2022
Accrued Expenses
Accrued Expenses	8. Accrued Expenses Accrued expenses consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2022 2021 Accrued research and development expenses ​ $ 13,559 ​ $ 24,977 Accrued employee compensation and benefits ​ ​ 8,316 ​ ​ 8,916 Accrued collaboration expenses ​ ​ 4,660 ​ ​ 835 Accrued legal, commercial and professional fees ​ 3,754 ​ 2,933 Other ​ 579 ​ 370 ​ ​ $ 30,868 ​ $ 38,031 ​

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2022
Share-Based Compensation
Share-Based Compensation	9. Share-Based Compensation The Company maintains several equity compensation plans, including the 2018 Incentive Award Plan (the “2018 Plan”), 2018 Employee Share Purchase Plan (the “2018 ESPP”), and Rilonacept Long-Term Incentive Plan (“RLTIP”) which was approved under the 2018 Plan. Upon the effectiveness of the 2018 Plan, the Company ceased granting awards under its 2015 Equity Incentive Plan (as amended, the “2015 Plan” and together with the 2018 Plan, the “Plans”). 2015 Plan As of September 30, 2022, there were 2,029,355 Class A common shares subject to outstanding awards under the 2015 Plan and reserved for issuance thereunder pursuant to such awards. 2018 Plan In May 2018, the Company’s board of directors and shareholders approved the 2018 Plan, which became effective on May 23, 2018. The 2018 Plan provides for the grant of incentive share options, nonqualified share options, share appreciation rights, restricted shares, dividend equivalents, restricted share units (“RSUs”) and other share- or cash- based awards. Pursuant to the 2018 Plan’s evergreen provision, the number of shares available for future issuance under the 2018 Plan, as of January 1, 2022, increased by 2,762,416 Class A common shares. As of September 30, 2022, 4,117,546 shares remained available for future grant under the 2018 Plan. 2018 ESPP In December 2021, pursuant to the 2018 ESPP’s evergreen provision, the Company’s board of directors approved an increase in the number of shares available for future issuance under the 2018 ESPP, as of January 1, 2022, of 90,000 Class A common shares. As of September 30, 2022, 604,290 Class A common shares were available for future issuance under the 2018 ESPP. ​ ​ ​ ​ ​ Options Share option activity under the Plans is summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ Number of ​ Average ​ ​ Shares ​ Exercise Price Outstanding as of December 31, 2021 9,226,846 ​ $ 14.14 Granted 2,792,460 ​ $ 11.22 Exercised (226,230) ​ $ 5.81 Forfeited (1,468,620) ​ $ 15.59 Outstanding as of September 30, 2022 10,324,456 ​ $ 13.32 Share options exercisable as of September 30, 2022 5,525,898 ​ $ 13.52 Share options unvested as of September 30, 2022 4,798,558 ​ $ 13.10 ​ As of September 30, 2022, total unrecognized compensation expense related to the unvested share option awards was $40,360 which is expected to be recognized over a weighted average remaining period of 2.73 years. ​ Restricted Share Units ​ Beginning in March 2021, the Company began granting RSUs with service conditions (“Time-Based RSUs”) to eligible employees as part of its equity incentive compensation. The Time-Based RSUs vest 25% on each of the first, second, third and fourth anniversaries of the date of grant, subject to continued employment through such dates. During the years ended December 31, 2020 and 2019, the Company granted the first RSU awards (“First RLTIP RSU Awards”) as part of the RLTIP to eligible employees. During the year ended December 31, 2021, the FDA Milestone (as defined in RLTIP) was achieved (the date of such achievement, the “Achievement Date”) and (1) the number of Class A common shares issuable under the First RLTIP RSU Awards were determined in accordance with the RLTIP and vested in one installment on the first anniversary of the Achievement Date, subject to continued employment through such date, and (2) the Company granted a second set of RSU awards to eligible employees on the Achievement Date with respect to a number of shares determined in accordance with the RLTIP, which will vest on the second anniversary of the Achievement Date, subject to continued employment through such date. During the three months ended September 30, 2022 and 2021, the Company recognized compensation expense of $1,146 and $838, respectively, related to RSUs including those granted in connection with the RLTIP. During the nine months ended September 30, 2022 and 2021, the Company recognized compensation expense of $2,697 and $2,868, respectively, related to RSUs including those granted in connection with the RLTIP. The following table summarizes RSU activity, including the RSUs outstanding under the RLTIP for the nine months ended September 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ Number of ​ Grant Date ​ ​ Shares ​ Fair Value Unvested RSUs as of December 31, 2021 ​ 885,021 ​ $ 15.72 Granted ​ 1,318,583 ​ $ 10.71 Vested ​ (229,151) ​ $ 15.79 Forfeited ​ (320,710) ​ $ 14.08 Unvested RSUs as of September 30, 2022 ​ 1,653,743 ​ $ 13.17 ​ As of September 30, 2022, total unrecognized compensation cost related to the RSU awards was $17,821 which is expected to be recognized over a weighted average remaining period of 3.38 years. Share-Based Compensation Share-based compensation expense was classified in the consolidated statements of operations and comprehensive loss as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ 2022 2021 ​ 2022 2021 Cost of goods sold ​ $ 164 ​ $ 62 ​ $ 456 ​ $ 101 Research and development expenses ​ ​ 1,532 ​ ​ 1,912 ​ ​ 5,116 ​ ​ 6,469 Selling, general and administrative expenses ​ 4,345 ​ 4,225 ​ 13,176 ​ 12,472 ​ ​ $ 6,041 ​ $ 6,199 ​ $ 18,748 ​ $ 19,042 ​

Out-Licensing Agreements

Out-Licensing Agreements	9 Months Ended
	Sep. 30, 2022
Out-licensing Agreements
Out-licensing Agreements	10. Genentech License Agreement On August 2, 2022, the Company entered into a license agreement (the “Genentech License Agreement”) with Genentech, Inc. and F. Hoffmann-La Roche Ltd (collectively, “Genentech”), pursuant to which the Company granted Genentech exclusive worldwide rights to develop, manufacture and commercialize vixarelimab and related antibodies (each, a “Genentech Licensed Product”). The Genentech License Agreement became effective on September 12, 2022 (the “Genentech Effective Date”) following termination of the statutory waiting period under the Hart-Scott Rodino Act. Under the Genentech License Agreement, the Company received an upfront payment of $80,000 for the license and is eligible to receive a near-term cash payment of $20,000 for delivery of certain materials to Genentech. In addition, the Company will be eligible to receive up to approximately $600,000 in contingent payments, including specified development, regulatory and sales-based milestones, before fulfilling the Company’s upstream financial obligations. The Company will also be eligible to receive tiered percentage royalties on a Genentech Licensed Product-by-Genentech Licensed Product basis ranging from low-double digits to mid-teens on annual net sales of each Genentech Licensed Product, subject to certain customary reductions, with an aggregate minimum floor, before fulfilling the Company’s upstream financial obligations. Royalties will be payable on a Genentech Licensed Product-by-Genentech Licensed Product and country-by-country basis until the latest to occur of the expiration of certain patents that cover a Genentech Licensed Product, the expiration of regulatory exclusivity for such Genentech Licensed Product, or the tenth anniversary of first commercial sale of such Genentech Licensed Product in such country. Pursuant and subject to the terms of the Genentech License Agreement, Genentech has the exclusive worldwide right to conduct development and commercialization activities for Genentech Licensed Products at its sole cost. Notwithstanding the foregoing, the Company is responsible, at its sole cost, for continuing to conduct and finalize its Phase 2b clinical trial assessing the efficacy, safety and tolerability of vixarelimab in reducing pruritis in prurigo nodularis. Both the Company and Genentech participate in a joint transition committee, which coordinates and oversees the technology and inventory transition activities relating to the development of the Genentech Licensed Products and the Company’s conduct and finalization of its Phase 2b clinical trial. The Company will provide to Genentech an initial drug supply and a drug product resupply and Genentech will be obligated to pay $20,000 to the Company after delivery of the last of such supply; provided Agreement at cost plus a markup. Under the Genentech License Agreement, Genentech has the right to assume manufacturing responsibilities for Genentech Licensed Products. Absent early termination, the Genentech License Agreement will continue until there are no more royalty or other payment obligations owed to the Company. Genentech has the right to terminate the Genentech License Agreement at its discretion with prior written notice and either party may terminate the Genentech License Agreement in the event of an uncured material breach of the other party or in the case of insolvency of the other party. In addition, the Genentech License Agreement will terminate upon termination of the Biogen Agreement (as defined below). The Company concluded that Genentech is a customer in this license agreement, and as such, the Genentech License Agreement falls within the scope of the revenue recognition guidance in ASC 606. Accounting for Genentech License Agreement As of the Genentech Effective Date, the Company identified the following material promises in the Genentech License Agreement: (i) the delivery of the exclusive license for vixarelimab; (ii) an initial drug supply delivery; (iii) a drug product resupply delivery; and (iv) completion of the Phase 2b clinical trial for vixarelimab. The Company also evaluated whether certain options outlined within the Genentech License Agreement represented material rights that would give rise to a performance obligation, including the option to purchase additional drug substance, and concluded that none of the options convey a material right to Genentech and therefore are not considered separate performance obligations within the Genentech License Agreement. The Company assessed the above promises and determined that the exclusive license for vixarelimab is reflective of a vendor-customer relationship and therefore represents a performance obligation. The exclusive license for vixarelimab is considered functional intellectual property and distinct from other promises under the Genentech License Agreement as Genentech can benefit from the license on its own or together with other readily available resources and the license is separately identifiable from the other promises. The initial drug supply and drug product resupply are considered distinct from the exclusive license for vixarelimab as Genentech can benefit from such supply together with the license transferred by the Company at the inception of the Genentech License Agreement. The completion of the Phase 2b clinical trial is considered distinct from the exclusive license for vixarelimab as Genentech can benefit from the data generated by such trial together with such license. Therefore, each represents a separate performance obligation within a contract with a customer at contract inception. The Company determined the transaction price at the inception of the Genentech License Agreement which consists of the $80,000 upfront payment. The Company determined that any variable consideration, including the $20,000 related to the delivery of the initial drug supply and drug product resupply and future development and regulatory milestones, are deemed fully constrained and therefore excluded from the transaction price due to the high degree of uncertainty and risk associated with these potential payments, as the Company also determined that it could not assert that it was not probable that a significant reversal in the amount of cumulative revenue recognized would occur. The Company also determined that royalties and sales milestones relate solely to the license of intellectual property. Revenue related to these royalties and sales milestones will only be recognized when the associated sales occur, and relevant thresholds are met, under the sales or usage-based royalty exception of Topic 606. As noted above, the Company identified four performance obligations in the Genentech License Agreement: (i) the delivery of the exclusive license for vixarelimab; (ii) an initial drug supply delivery; (iii) a drug product resupply delivery; and (iv) completion of the Phase 2b clinical trial for vixarelimab. The selling price of each performance obligation in the Genentech License Agreement was determined based on the Company’s standalone selling price (“SSP”) with the objective of determining the price at which it would sell such an item if it were to be sold regularly on a standalone basis. The Company allocated the transaction price to the exclusive license, initial drug supply delivery, drug product resupply delivery and completion of the Phase 2b clinical trial for vixarelimab. The Company recognizes revenue for the license performance obligations at a point in time, that is upon transfer of the license to Genentech. As control of the license was transferred on the Genentech Effective Date and Genentech could begin to use and benefit from the license, the Company recognized $65,711 of collaboration revenue during the three and nine months ended September 30, 2022 under the Genentech License Agreement. The Company will recognize revenue for deliveries of certain drug supply to Genentech at a point in time upon delivery. The Company will recognize revenue for the completion of the Phase 2b clinical trial for vixarelimab over time using the cost-to-cost input method, which it believes best depicts the transfer of control to the customer. Under the cost-to-cost input method, the extent of progress towards completion is measured based on the ratio of actual costs incurred to the total estimated costs expected upon satisfying the identified performance obligation. Under this method, revenue is recorded as a percentage of the allocated transaction price based on the progress of completion. The calculation of the total estimated costs to fulfill the performance obligation includes costs associated with employees, development, manufacturing, and out-of-pocket costs expected to be paid to third parties. Huadong Collaboration Agreements On February 21, 2022 (the “Effective Date”), the Company entered into two collaboration and license agreements (each, a “Collaboration Agreement” and together, the “Collaboration Agreements”) with Hangzhou Zhongmei Huadong Pharmaceutical Co., Ltd. (“Huadong”), pursuant to which the Company granted Huadong exclusive rights to develop and commercialize rilonacept and develop, manufacture and commercialize mavrilimumab (each, a “Licensed Product” and together, the “Licensed Products”) in the following countries: People’s Republic of China, Hong Kong SAR, Macao SAR, Taiwan Region, South Korea, Indonesia, Singapore, The Philippines, Thailand, Australia, Bangladesh, Bhutan, Brunei, Burma, Cambodia, India, Laos, Malaysia, Maldives, Mongolia, Nepal, New Zealand, Sri Lanka, and Vietnam (collectively, the “Territory”). Under the Collaboration Agreements, the Company received a total upfront cash payment of $22,000, which includes $12,000 for the Territory license of rilonacept and $10,000 for the Territory license of mavrilimumab. The Company will be eligible to receive up to approximately $70,000 in payments for rilonacept, and up to approximately $576,000 in payments for mavrilimumab, including specified development, regulatory and sales-based milestones. Huadong will also be obligated to pay the Company tiered percentage royalties on a Licensed Product-by-Licensed Product basis ranging from the low-teens to low-twenties on annual net sales of each Licensed Product in the Territory, subject to certain reductions tied to rilonacept manufacturing costs and certain other customary reductions, with an aggregate minimum floor. Royalties will be payable on a Licensed Product-by-Licensed Product and country-by-country or region-by-region basis until the later of (i) 12 years after the first commercial sale of the applicable Licensed Product in such country or region in the Territory, (ii) the date of expiration of the last valid patent claim of the Company’s patent rights or any joint collaboration patent rights that covers the applicable Licensed Product in such country or region in the Territory, and (iii) the expiration of the last regulatory exclusivity for the applicable Licensed Product in such country or region in the Territory. Pursuant and subject to the terms of the Collaboration Agreements, Huadong has the exclusive right to conduct Territory-specific development activities for the Licensed Products in the Territory, the first right to support global development of the Licensed Products by serving as the sponsor of the global clinical trials conducted in the Territory and the exclusive right to commercialize the Licensed Products in the Territory. Huadong will be responsible for all costs of development activities and commercialization in the Territory. Both the Company and Huadong participate in a Joint Steering Committee (“JSC”), which coordinates and oversees the exploitation of the Licensed Products in the Territory. The Company will supply certain materials to support development and commercialization activities for both mavrilimumab and rilonacept. Under the Collaboration Agreement for mavrilimumab, Huadong has the right to assume manufacturing responsibilities for materials in the Territory. Under the Collaboration Agreement for rilonacept, Huadong does not have rights to perform manufacturing activities in the Territory. Absent early termination, each Collaboration Agreement will continue on a country-by-country or region-by-region basis until there are no more royalty payments owed to the Company in such country or region for the applicable Licensed Product. Huadong has the right to terminate each Collaboration Agreement at its discretion upon 12 months’ notice and either party may terminate the applicable Collaboration Agreement in the event of an uncured material breach of the other party or in the case of insolvency of the other party. In addition, the Company may terminate the applicable Collaboration Agreement if Huadong or its affiliates or sublicensees challenges the scope, validity, or enforceability of the Company’s patent rights being licensed to Huadong. If Huadong and its affiliates do not conduct any material development or commercialization activities with respect to a Licensed Product in the People’s Republic of China for a continuous period of longer than six months, then, subject to certain exceptions, the Company may terminate the Collaboration Agreement applicable to such Licensed Product with 60 days’ prior written notice. In addition, Huadong’s rights under each Collaboration Agreement in certain regions within the Territory may be subject to termination upon failure by Huadong to perform certain clinical, development or commercialization activities, as applicable, with respect to the applicable Licensed Product in such regions. The Company concluded that Huadong is a customer in these Collaboration Agreements, and as such, each Collaboration Agreement falls within the scope of the revenue recognition guidance in ASC 606. The Company concluded that the Collaboration Agreements should not be combined and treated as a single arrangement for accounting purposes as the Collaboration Agreements were negotiated separately with separate and distinct commercial objectives, the amount of consideration in one Collaboration Agreement is not dependent on the price or performance of the other Collaboration Agreement, and the goods and services promised in the Collaboration Agreements are not a single performance obligation. Accounting for Mavrilimumab Collaboration Agreement As of the Effective Date, the Company identified the following material promises in the mavrilimumab Collaboration Agreement: delivery of (i) exclusive license for mavrilimumab in the Territory and (ii) clinical manufacturing supply of certain materials for mavrilimumab products in the Territory. The Company also evaluated whether certain options outlined within the mavrilimumab Collaboration Agreement represented material rights that would give rise to a performance obligation and concluded that none of the options convey a material right to Huadong and therefore are not considered separate performance obligations within the mavrilimumab Collaboration Agreement. The Company assessed the above promises and determined that the exclusive license for mavrilimumab in the Territory is reflective of a vendor-customer relationship and therefore represents a performance obligation. The exclusive license for mavrilimumab in the Territory is considered functional intellectual property and distinct from other promises under the Collaboration Agreement as Huadong can benefit from the license on its own or together with other readily available resources and the license is separately identifiable from the other promises. The clinical manufacturing supply of certain materials for mavrilimumab products in the Territory is considered distinct from the exclusive license for mavrilimumab as Huadong can benefit from the manufacturing services together with the license transferred by the Company at the inception of the Collaboration Agreement. Therefore, each represents a separate performance obligation within a contract with a customer at contract inception. The Company determined the transaction price at the inception of the mavrilimumab Collaboration Agreement which includes $10,000, consisting of the upfront payment. The Company also includes an estimate of variable consideration associated with the clinical manufacturing supply of certain materials when those materials are shipped. The Company determined that any variable consideration related to development and regulatory milestones is deemed fully constrained and therefore excluded from the transaction price due to the high degree of uncertainty and risk associated with these potential payments, as the Company determined that it could not assert that it was probable that a significant reversal in the amount of cumulative revenue recognized will not occur. The Company also determined that royalties and sales milestones relate solely to the licenses of intellectual property. Revenue related to these royalties and sales milestones will only be recognized when the associated sales occur, and relevant thresholds are met, under the sales or usage-based royalty exception of Topic 606. As noted above, the Company identified two performance obligations in the mavrilimumab Collaboration Agreement: (i) the delivery of the exclusive license for mavrilimumab in the Territory; and (ii) the clinical manufacturing supply of certain materials for mavrilimumab products in the Territory. The selling price of each performance obligation in the mavrilimumab Collaboration Agreement was determined based on the Company’s standalone selling price (“SSP”) with the objective of determining the price at which it would sell such an item if it were to be sold regularly on a standalone basis. The Company allocated the variable consideration related to the manufacturing obligations to the future clinical supply of mavrilimumab products in the Territory and the remaining fixed and variable consideration to the license obligation. The Company recognizes revenue for the license performance obligations at a point in time, that is upon transfer of the license to Huadong. As control of the license was transferred on the Effective Date and Huadong could begin to use and benefit from the license, the Company recognized $10,000 of collaboration revenue during the nine months ended September 30, 2022 under the mavrilimumab Collaboration Agreement. The Company will recognize revenue for the clinical manufacturing supply obligations at a point in time, that is upon each delivery of the supply to Huadong. ​ Accounting for Rilonacept Collaboration Agreement As of the Effective Date, the Company identified the following material promises in the rilonacept Collaboration Agreement that were evaluated: delivery of (i) exclusive license for rilonacept in the Territory; (ii) clinical manufacturing supply of certain materials for rilonacept products in the Territory; and (iii) commercial manufacturing supply of certain material for rilonacept products in the Territory. The Company also evaluated whether certain options outlined within the rilonacept Collaboration Agreement represented material rights that would give rise to a performance obligation and concluded that none of the options convey a material right to Huadong and therefore are not considered separate performance obligations within the rilonacept Collaboration Agreement. The Company assessed the above promises and determined that there is one combined performance obligation for the exclusive license for rilonacept and clinical and commercial manufacturing obligations for rilonacept products in the Territory. Huadong cannot exploit the value of the exclusive license for rilonacept products in the Territory without receipt of supply as the exclusive license for rilonacept products in the Territory does not convey to Huadong the right to manufacture and therefore the Company has combined the exclusive license for rilonacept products in the Territory and the manufacturing obligations into one performance obligation. ​ The Company determined the transaction price at the inception of the rilonacept Collaboration Agreement which includes $12,000, consisting of the upfront payment. The Company also includes an estimate of variable consideration associated with the clinical manufacturing supply of certain materials when those materials are shipped. The Company determined that any variable consideration related to development and regulatory milestones, sales milestones and royalties are deemed fully constrained and therefore excluded from the transaction price due to the high degree of uncertainty and risk associated with these potential payments, as the Company determined that it could not assert that it was probable that a significant reversal in the amount of cumulative revenue recognized will not occur. Royalties and sales milestones will be recognized as the Company delivers the commercial manufactured product to Huadong. Any changes in estimates may result in a cumulative catch-up based on the number of units of manufactured product delivered. ​ As noted above, the Company identified a single combined performance obligation in the rilonacept Collaboration Agreement consisting of the exclusive license for rilonacept and clinical and commercial manufacturing obligations for rilonacept products in the Territory. The Company recognizes revenue for the combined performance obligation consisting of the exclusive license for rilonacept and clinical and commercial manufacturing obligations for rilonacept products in the Territory at a point in time, upon which control of materials are transferred to Huadong for each delivery of the associated materials. The Company currently expects to recognize the revenue over the life of the agreement. This estimate considers the timing of development and commercial activities under the rilonacept Collaboration Agreement and may be reduced or increased based on changes in the various activities. ​ The Company has not recognized any revenue under the rilonacept Collaboration Agreement for the three and nine months ended September 30, 2022 as there has been no delivery of materials under the rilonacept Collaboration Agreement to date. The full transaction price of $12,000 is recorded in long-term deferred revenue, based upon timing of anticipated future shipments. ​ The following table summarizes deferred revenue in connection with license and collaboration agreements for the nine months ended September 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at ​ ​ ​ ​ ​ ​ Balance at End ​ ​ Beginning of Period ​ Additions ​ Deductions ​ of Period Nine Months Ended September 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Huadong rilonacept ​ $ — ​ $ 12,000 ​ $ — ​ $ 12,000 Genentech vixarelimab ​ ​ — ​ ​ 14,290 ​ ​ — ​ ​ 14,290 Deferred revenue ​ $ — ​ $ 26,290 ​ $ — ​ $ 26,290 ​

In-license, Acquisition and Col

In-license, Acquisition and Collaboration Agreements	9 Months Ended
	Sep. 30, 2022
License, Acquisition and Collaboration Agreements
In-license, Acquisition and Collaboration Agreements	11. In-license, Acquisition and Collaboration Agreements Biogen Asset Purchase Agreement In September 2016, the Company entered into an asset purchase agreement (the “Biogen Agreement”) with Biogen MA Inc. (“Biogen”) to acquire all of Biogen’s right, title and interest in and to certain assets used in or relating to vixarelimab and other antibodies covered by certain patent rights, including patents and other intellectual property rights, clinical data, know-how, and clinical drug supply. In addition, Biogen granted to the Company a non-exclusive, sublicensable, worldwide license to certain background patent rights related to the vixarelimab program. The Company is obligated to use commercially reasonable efforts to develop and commercialize such acquired products. Under the Biogen Agreement, the Company is obligated to make milestone payments to Biogen of up to $179,000 upon the achievement of specified clinical and regulatory milestones in multiple indications in various territories, of which $165,000 remains as of September 30, 2022. Additionally, the Company could be obligated to make up to an aggregate of up to $150,000 of payments upon the achievement of specified annual net sales milestones and to pay tiered royalties on escalating tiers of annual net sales of licensed products starting in the high single-digit percentages and ending below the teens. The Company also agreed to pay certain obligations under third-party contracts retained by Biogen that relate to the vixarelimab program. Under these retained contracts, the Company paid a one-time upfront sublicense fee and is obligated to pay insignificant annual maintenance fees as well as clinical and regulatory milestone payments of up to an aggregate of $1,575. The Biogen Agreement will terminate upon the expiration of all payment obligations with respect to the last product in all countries in the territory. The Company has the right to terminate the agreement with 90 days’ prior written notice. Both parties may terminate by mutual written consent or in the event of material breach of the agreement by the other party that remains uncured for 90 days (or 30 days for payment-related breaches). In July 2017, the Company and Biogen entered into Amendment No. 1 to the Biogen Agreement, which clarified the scope of the antibodies subject to the Biogen Agreement. On August 2, 2022, the Company entered into Amendment No. 2 to the Biogen Agreement (the “Second Biogen Amendment”). Pursuant to the terms of the Second Biogen Amendment, commencing on the effective date of the Genentech License Agreement, certain defined terms in the Biogen Agreement were amended, including “Net Sales”, “Indication”, “Product”, “Combination Product” and “Valid Claim”. In addition, the tiered royalty rates to be paid by the Company to Biogen increased by an amount equal to less than one percent. Upon the termination or expiration of the Genentech License Agreement, the amendments to the terms of the Biogen Agreement, as set forth in the Second Biogen Amendment, will terminate and all terms of the Biogen Agreement will revert to the version of such terms in effect as of immediately prior to the effective date of the Genentech License Agreement. During the three and nine months ended September 30, 2022, the Company recorded research and development expense of $11 and $45, respectively, related to the annual maintenance in connection with the Biogen Agreement. During the three and nine months ended September 30, 2021, the Company recorded research and development expense of $14 and $42 respectively, related to the annual maintenance fee in connection with the retained contracts. Beth Israel Deaconess Medical Center License Agreement In 2019, the Company exercised the call option under the stock purchase option agreement with Primatope and acquired all of the outstanding securities of Primatope (the “Primatope Acquisition”). As a result of the Primatope Acquisition, the Company acquired the rights to an exclusive license to certain intellectual property rights controlled by Beth Israel Deaconess Medical Center, Inc. (“BIDMC”) to make, use, develop and commercialize KPL-404 (the “BIDMC Agreement”). Under the BIDMC Agreement, the Company is solely responsible for all development, regulatory and commercial activities and costs. The Company is also responsible for costs related to filing, prosecuting and maintaining the licensed patent rights. Under the BIDMC Agreement, the Company is obligated to pay an insignificant annual maintenance fee as well as clinical and regulatory milestone payments of up to an aggregate of $1,200 to BIDMC. The Company is also obligated to pay a low single-digit royalty on annual net sales of products licensed under the agreement. During the three and nine months ended September 30, 2022 and 2021, the Company did not record any research and development expense in connection with the BIDMC Agreement. Regeneron License Agreement In September 2017, the Company entered into a license agreement (the “Regeneron Agreement”) with Regeneron Pharmaceuticals, Inc. (“Regeneron”), pursuant to which the Company has been granted an exclusive license under certain intellectual property rights controlled by Regeneron to develop and commercialize ARCALYST worldwide, excluding the Middle East and North Africa, for all indications other than those in oncology and local administration to the eye or ear. Upon receiving positive data in RHAPSODY, the Company’s pivotal Phase 3 clinical trial of ARCALYST, Regeneron transferred the biologics license application, for ARCALYST to the Company. In March 2021, when the FDA granted approval of ARCALYST for the treatment of recurrent pericarditis and reduction in risk of recurrence in adults and children 12 years and older, the Company assumed the sales and distribution of ARCALYST for Cryopyrin-Associated Periodic Syndromes and Deficiency of Interleukin-1 Receptor Antagonist in the United States. ​ The Company made a $20,000 payment in the first quarter of 2021 in connection with the achievement of a specified regulatory milestone event. The $20,000 milestone was accounted for as an intangible asset and will be amortized over the life of the underlying asset. Related amortization expense will be recorded as cost of goods sold in the Company’s consolidated statement of operations and comprehensive loss. The Company evenly splits profits on sales of ARCALYST with Regeneron, where profits are determined after deducting from net sales of ARCALYST certain costs related to the manufacturing and commercialization of ARCALYST. Such costs include but are not limited to (i) the Company’s cost of goods sold for product used, sold or otherwise distributed for patient use by the Company; (ii) customary commercialization expenses, including the cost of the Company’s field force, and (iii) the Company’s cost to market, advertise and otherwise promote ARCALYST, with such costs identified in subsection (iii) subject to specified limits.  In addition, should there be a transfer of technology related to the manufacture of ARCALYST, then, to the extent permitted in accordance with the Regeneron Agreement, the fully-burdened costs incurred by each of the Company and Regeneron in performing (or having performed) such technology transfer shall also be deducted from net sales of ARCALYST to determine profit. The Company also evenly splits with Regeneron any proceeds received by the Company from any licensees, sublicensees and distributors in consideration for the sale, license or other disposition of rights with respect to ARCALYST, including upfront payments, milestone payments and royalties. For the three and nine months ended September 30, 2022, the Company recognized $4,623 and $16,549 respectively, of expenses related to the profit sharing agreement presented within collaboration expenses. The Company recorded $6,000 of profit sharing expense in February 2022 related to the rilonacept Collaboration Agreement. For the three and nine months ended September 30, 2021 the Company did not recognize any collaboration expenses related to the profit sharing agreement. ​ Pursuant to the Regeneron Agreement, in September 2017, the parties entered into a clinical supply agreement under which Regeneron agreed to manufacture materials solely for the Company’s use in development activities. Pursuant to the Regeneron Agreement, during the year ended December 31, 2021, the Company entered into a commercial supply agreement under which Regeneron agreed to manufacture product for the Company’s use, including for commercial sales. The commercial supply agreement terminates upon the termination of the Regeneron Agreement or the date of completion of the transfer of technology related to the manufacture of ARCALYST. During the three and nine months ended September 30, 2022 and 2021, the Company did not incur any research and development expense related to the purchase of drug materials under the clinical supply agreement. As of September 30, 2022 and December 31, 2021, the Company recorded inventory of $14,621 and $3,675, respectively, related to the purchase of commercial product under the commercial supply agreement (see Note 5). As of September 30, 2022, the Company had non-cancelable purchase commitments under the commercial supply agreement (see Note 14). The Regeneron Agreement will expire when the Company is no longer developing or commercializing any licensed product under the Regeneron Agreement. Either party may terminate the agreement upon the other party’s insolvency or bankruptcy or for material breach of the agreement by the other party that remains uncured for 90 days (or 30 days for payment related breaches). Regeneron has the right to terminate the agreement if the Company suspends its development or commercialization activities for a consecutive 12 month period or does not grant a sublicense to a third party to perform such activities, or if the Company challenges any of the licensed patent rights. The Company may terminate the agreement at any time with one year’s written notice. The Company may also terminate the agreement with three months’ written notice if the licensed product is determined to have certain safety concerns. MedImmune License Agreement In December 2017, the Company entered into a license agreement (as amended from time to time, the “MedImmune Agreement”) with MedImmune, Limited (“MedImmune”), pursuant to which MedImmune granted the Company an exclusive, sublicensable, worldwide license to certain intellectual property rights to make, use, develop and commercialize mavrilimumab. Under the MedImmune Agreement, the Company also acquired reference rights to relevant manufacturing and regulatory documents and MedImmune’s existing supply of mavrilimumab drug substance and product. The Company is obligated to use commercially reasonable efforts to develop and commercialize the licensed products. The Company is obligated to make clinical, regulatory and initial sales milestone payments of up to $72,500 in aggregate for the first two indications, of which $57,500 remain as of September 30, 2022. In addition, the Company is obligated to make clinical and regulatory milestone payments of up to $15,000 in the aggregate for each subsequent indication. In July 2020, the Company entered into an amendment to the MedImmune Agreement to establish a new coronavirus field and defer the payment of certain development and regulatory milestones as applied to the new coronavirus field. The Company is obligated to make milestone payments to MedImmune of up to $85,000 upon the achievement of annual net sales thresholds up to, but excluding, $1,000,000 in annual net sales as well as additional milestone payments aggregating up to $1,100,000 upon the achievement of additional specified annual net sales thresholds starting at $1,000,000 and higher. The Company has also agreed to pay tiered royalties on escalating tiers of annual net sales of licensed products starting in the low double-digit percentages and ending at twenty percent. Royalty rates are subject to reductions upon certain events. ​ The Company is solely responsible for all development, manufacturing, and commercial activities and costs of the licensed products, including clinical studies or other tests necessary to support the use of a licensed product. The Company is also responsible for costs related to the filing, prosecution and maintenance of the licensed patent rights. The MedImmune Agreement will expire upon the expiration of the royalty term in the last country for the last indication, as defined in the agreement. Either party may terminate the agreement upon the other party’s insolvency or bankruptcy or for material breach of the agreement by the other party that remains uncured for 90 days. MedImmune has the right to terminate the agreement if the Company challenges any of the licensed patent rights. The Company may terminate the agreement at any time upon 90 days’ prior written notice. During the three and nine months ended September 30, 2022 and 2021, the Company did not record research and development expense in connection with milestone payments due under the MedImmune Agreement.

Earnings (Loss) per Share

Earnings (Loss) per Share	9 Months Ended
	Sep. 30, 2022
Earnings (Loss) per Share
Earnings (Loss) per Share	​ 12. Earnings (Loss) per Share The rights, including the liquidation and dividend rights, of the holders of Class A, Class B, Class A1 and Class B1 common shares are identical, except with respect to voting, transferability and conversion (see the Notes to Consolidated Financial Statements to our Form 10-K ​ Basic and diluted EPS attributable to common shareholders was calculated as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ 2022 2021 2022 2021 Numerator: ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) attributable to common shareholders ​ $ 224,093 ​ $ (30,544) ​ $ 178,902 ​ $ (121,591) Denominator: ​ ​ ​ ​ Weighted-average basic shares outstanding ​ 69,445,071 ​ 68,662,673 ​ 69,305,755 ​ 68,444,061 Effect of dilutive securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options to purchase common shares ​ ​ 937,492 ​ ​ — ​ ​ 906,866 ​ ​ — Unvested RSUs ​ ​ 169,455 ​ ​ — ​ ​ 73,823 ​ ​ — Weighted-average diluted shares ​ ​ 70,552,018 ​ ​ 68,662,673 ​ ​ 70,286,444 ​ ​ 68,444,061 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic EPS ​ $ 3.23 ​ $ (0.44) ​ $ 2.58 ​ $ (1.78) Diluted EPS ​ $ 3.18 ​ $ (0.44) ​ $ 2.55 ​ $ (1.78) ​ The Company’s unvested RSUs have been excluded from the computation of basic net loss per share attributable to common shareholders. Diluted earnings per share includes the assumed exercise of dilutive options and the assumed issuance of unvested RSUs and performance-based awards for which the performance condition has been met as of the date of determination, using the treasury stock method unless the effect is anti-dilutive. The treasury stock method assumes that proceeds, including cash received from the exercise of employee stock options and the average unrecognized compensation expense for unvested share-based compensation awards, would be used to purchase the Company’s common stock at the average market price during the period. For the three and nine months ended September 30, 2021 the Company’s potentially dilutive securities, which include options and unvested RSUs, have been excluded from the computation of diluted net loss per share attributable to common shareholders for the periods indicated as the effect would be to reduce the EPS attributable to common shareholders. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted EPS attributable to common shareholders is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted EPS attributable to common shareholders for the periods indicated because including them would have had an anti-dilutive effect: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ September 30, ​ September 30, ​ 2022 2021 2022 2021 Options to purchase common shares ​ 8,472,937 ​ ​ 9,556,481 ​ ​ 8,880,055 ​ ​ 9,556,481 Unvested RSUs ​ 837,457 ​ ​ 801,154 ​ ​ 1,547,383 ​ ​ 801,154 ​ ​ 9,310,394 ​ ​ 10,357,635 ​ ​ 10,427,438 ​ ​ 10,357,635 ​

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2022
Income Taxes
Income Taxes	13. Income Taxes The Company is an exempted company incorporated under the laws of Bermuda. Under the current laws of Bermuda, income tax is not charged or levied on an exempted company’s income. As a result, the Company has not recorded any income tax benefits from losses incurred in Bermuda during each reporting period, and no net operating loss carryforwards will be available to the Company for those losses. The Company’s wholly owned U.S. subsidiaries, Kiniksa US and Primatope, are subject to federal and state income taxes in the United States. The Company’s wholly owned subsidiary Kiniksa UK, and its wholly owned subsidiaries, Kiniksa Germany, Kiniksa France, and Kiniksa Switzerland are subject to taxation in their respective countries. Certain of the Company’s subsidiaries, primarily Kiniksa US, operate under cost plus arrangements. ​ Although Bermuda has no corporate income tax the Company’s income tax rate for the three and nine months ended September 30, 2022 is due to income subject to United Kingdom taxation and United States taxation under the Kiniksa US cost plus arrangements with the Company, and U.S. federal and state research tax credits (“R&D credits”). Income tax benefit for the three and nine months ended September 30, 2022 was $177,358 and $174,717, respectively. The benefit for income taxes is primarily driven by the release of the valuation allowance on the Company’s UK deferred tax assets in the third quarter. ​ Management regularly reassesses the valuation allowance on the Company’s deferred income tax assets. Valuation allowances require an assessment of both positive and negative evidence when determining whether it is more likely than not that the Company will be able to recover its deferred tax assets. Such assessment is required on a jurisdiction-by-jurisdiction basis. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. ​ In the third quarter of 2022, the Company assessed the valuation allowance on its UK deferred tax assets and considered positive evidence, including cumulative UK income in recent years, continued commercial execution of ARCALYST, and expectations regarding future probability. After assessing both the positive evidence and negative evidence, the Company determined it was more likely than not that its UK deferred tax assets would be realized in the future and released the associated valuation allowance as of September 30, 2022. This resulted in a benefit of $185,843. As of September 30, 2022, the Company maintained a full valuation allowance against its U.S. deferred tax assets. There are no material deferred tax assets in the jurisdictions outside Kiniksa US and Kiniksa UK. ​ The Company transferred all of its rights, title and interest in, among other things, certain contracts (including the Biogen Agreement), intellectual property rights, product filings and approvals and other information, plans and materials owned or controlled by the Company insofar as they related exclusively or primarily to vixarelimab to Kiniksa UK in July 2022 pursuant to an asset transfer agreement between the Company and Kiniksa UK for the consideration described therein.  The Company did not incur any material tax liabilities in connection with the transfer and Kiniksa UK received a stepped up basis in the property. ​

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2022
Commitments and Contingencies
Commitments and Contingencies	14. Commitments and Contingencies License Agreements The Company entered into license agreements with various parties under which it is obligated to make contingent and non-contingent payments (see Note 11). Manufacturing Commitments The Company entered into a commercial supply agreement with Regeneron to provide both clinical supply and commercial product (see Note 11). The Company entered into agreements with several CMOs to provide the Company with preclinical and clinical trial materials. As of September 30, 2022, the Company had committed to minimum payments under these agreements totaling $33,019 all of which are due within one year. Indemnification Agreements The Company is not aware of any claims under indemnification arrangements that are expected to have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its consolidated financial statements as of September 30, 2022 or December 31, 2021. Legal Proceedings The Company is not a party to any material litigation and does not have contingency reserves established for any litigation liabilities.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2022
Summary of Significant Accounting Policies
Principles of Consolidation	Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and include the accounts of the Company and its wholly owned subsidiaries, Kiniksa Pharmaceuticals Corp. (“Kiniksa US”), Primatope Therapeutics, Inc. (“Primatope”) and Kiniksa Pharmaceuticals (UK), Ltd. (“Kiniksa UK”) as well as the subsidiaries of Kiniksa UK, Kiniksa Pharmaceuticals (Germany) GmbH (“Kiniksa Germany”), Kiniksa Pharmaceuticals (France) SARL (“Kiniksa France”), and Kiniksa Pharmaceuticals GmbH (“Kiniksa Switzerland”), after elimination of all significant intercompany accounts and transactions.
Use of Estimates	Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of expenses during the reporting period. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the recognition of revenue, the capitalization of inventory, the accrual for research and development expenses, the valuation of share-based awards and the realizability of deferred tax assets. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from those estimates.
Unaudited Interim Consolidated Financial Information	Unaudited Interim Consolidated Financial Information The accompanying unaudited consolidated financial statements have been prepared in accordance with GAAP for interim financial information. The accompanying unaudited consolidated financial statements do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. The information included in this quarterly report on Form 10-Q should be read in conjunction with the Company’s audited consolidated financial statements and the accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021 (the “2021 Form 10-K”). The Company’s accounting policies are described in the Notes to Consolidated Financial Statements in the Company’s 2021 Form 10-K and updated, as necessary, in this report. The accompanying year-end consolidated balance sheet was derived from audited financial statements but does not include all disclosures required by GAAP. The unaudited interim consolidated financial statements have been prepared on the same basis as the audited annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of September 30, 2022 and the results of its operations for the three and nine months ended September 30, 2022 and 2021, the changes in its shareholders’ equity for the three and nine months ended September 30, 2022 and 2021 and its cash flows for the nine months ended September 30, 2022 and 2021. The results for the three and nine months ended September 30, 2022 are not necessarily indicative of results to be expected for the year ending December 31, 2022, any other interim periods or any future year or period.
Liquidity	Liquidity The Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date the consolidated financial statements are issued. As of September 30, 2022, the Company had an accumulated deficit of $496,495. During the nine months ended September 30, 2022, the Company reported net income of $178,902 and provided $17,383 cash in operating activities. As of September 30, 2022, the Company had cash, cash equivalents and short-term investments of $200,724. Based on its current operating plan, the Company expects that its cash, cash equivalents and short-term investments will be sufficient to fund its operations and capital expenditure requirements for at least twelve months from the issuance date of these consolidated financial statements. The future viability of the Company beyond that point is dependent on its ability to fund its operations through sales of ARCALYST and/or raise additional capital, as needed. If the Company is unable to grow sales of ARCALYST in future periods, the Company would need to seek additional financing through public or private securities offerings, debt financings, government funding or grants, or other sources, which may include licensing, collaborations or other strategic transactions or arrangements. Although the Company has been successful in raising capital in the past, there is no assurance that it will be successful in obtaining such additional financing on terms acceptable to the Company, if at all. If the Company is unable to obtain funding, the Company could be forced to delay, reduce or eliminate some or all of its commercialization efforts, research and development programs for product candidates or product portfolio expansion, which could adversely affect its business prospects, or the Company may be unable to continue operations.
Revenue Recognition	​ ASC Topic 606, Revenue from Contracts with Customers (“ASC 606”) outlines a five-step process for recognizing revenue from contracts with customers: (i) identify the contract with the customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the separate performance obligations in the contract, and (v) recognize revenue associated with the performance obligations as they are satisfied. ​ The Company only applies the five-step model to contracts when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. Once a contract is determined to be within the scope of ASC 606, the Company determines the performance obligations that are distinct. The Company recognizes as revenues the amount of the transaction price that is allocated to each respective performance obligation when the performance obligation is satisfied. Generally, the Company’s performance obligations are transferred to customers at a point in time, typically upon delivery of the product to the customer. ​ ASC 606 requires entities to record a contract asset when a performance obligation has been satisfied or partially satisfied, but the amount of consideration has not yet been received because the receipt of the consideration is conditioned on something other than the passage of time. ASC 606 also requires an entity to present a revenue contract as a contract liability in instances when a customer pays consideration, or an entity has a right to an amount of consideration that is unconditional (e.g., receivable), before the entity transfers a good or service to the customer.
Collaboration Revenue	Collaboration Revenue The Company analyzes its collaboration arrangements to assess whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities and therefore within the scope of ASC Topic 808, Collaborative Arrangements (“Topic 808”). This assessment is performed throughout the life of the arrangement based on changes in the responsibilities of all parties in the arrangement. For collaboration arrangements within the scope of Topic 808 that contain multiple elements, the Company first determines which elements of the collaboration are deemed to be within the scope of Topic 808 and which elements of the collaboration are more reflective of a vendor-customer relationship and therefore within the scope of Topic 606. For elements of collaboration arrangements that are accounted for pursuant to ASC 606, we identify the performance obligations and allocate the total consideration we expect to receive on a relative standalone selling price basis to each performance obligation. Variable consideration such as performance-based milestones will be included in the total consideration if we expect to receive such consideration and if it is probable that the inclusion of the variable consideration will not result in a significant reversal in the cumulative amount of revenue recognized under the arrangement. Our estimate of the total consideration we expect to receive under each collaboration arrangement is updated for each reporting period, and any adjustments to revenue are recorded on a cumulative catch-up basis. We exclude sales-based royalty and milestone payments from the total consideration we expect to receive until the underlying sales occur because the license to our intellectual property is deemed to be the predominant item to which the royalties or milestones relate as it is the primary driver of value in our collaboration arrangements. Key assumptions to determine the standalone selling price may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success. We recognize revenue associated with each performance obligation as the control over the promised goods or services transfer to our collaboration partner which occurs either at a point in time or over time. If control transfers over time, revenue is recognized by using a method of measuring progress that best depicts the transfer of goods or services. We evaluate the measure of progress and related inputs each reporting period and any resulting adjustments to revenue are recorded on a cumulative catch-up basis. Consideration received that does not meet the requirements to satisfy ASC 808 or ASC 606 revenue recognition criteria is recorded as deferred revenue in the accompanying consolidated balance sheets, classified as either short-term (less than 12 months) or long-term (more than 12 months) deferred revenue based on our best estimate of when such revenue will be recognized. There have been no other material changes to the significant accounting policies previously disclosed in the Company’s 2021 Form 10-K.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements

Fair Value of Financial Asset_2

Fair Value of Financial Assets and Liabilities (Tables)	9 Months Ended
	Sep. 30, 2022
Fair Value of Financial Assets and Liabilities
Schedule of financial assets and liabilities measured at fair value on a recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ as of September 30, 2022 Using: ​ Level 1 Level 2 Level 3 Total Assets: ​ ​ ​ ​ Cash equivalents — money market funds ​ $ 39,533 ​ $ — ​ $ — ​ $ 39,533 Short-term investments — U.S. Treasury notes ​ ​ — ​ ​ 24,963 ​ ​ — ​ ​ 24,963 ​ ​ $ 39,533 ​ $ 24,963 ​ $ — ​ $ 64,496 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ as of December 31, 2021 Using: ​ Level 1 Level 2 Level 3 Total Assets: ​ ​ ​ ​ Cash equivalents — money market funds ​ $ 94,324 ​ $ — ​ $ — ​ $ 94,324 Short-term investments — U.S. Treasury notes ​ ​ — ​ ​ 59,731 ​ ​ — ​ ​ 59,731 ​ ​ $ 94,324 ​ $ 59,731 ​ $ — ​ $ 154,055
Schedule of short-term investments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Credit ​ Fair ​ ​ Cost ​ Gains ​ Losses ​ Losses ​ Value September 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Short-term investments — U.S. Treasury notes ​ $ 24,986 ​ $ — ​ $ (23) ​ $ — ​ $ 24,963 ​ ​ $ 24,986 ​ $ — ​ $ (23) ​ $ — ​ $ 24,963 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Credit ​ Fair ​ ​ Cost ​ Gains ​ Losses ​ Losses ​ Value December 31, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Short-term investments — U.S. Treasury notes ​ $ 59,745 ​ $ 1 ​ $ (15) ​ $ — ​ $ 59,731 ​ ​ $ 59,745 ​ $ 1 ​ $ (15) ​ $ — ​ $ 59,731

Product Revenue, Net (Tables)

Product Revenue, Net (Tables)	9 Months Ended
	Sep. 30, 2022
Product Revenue, Net
Schedule of product revenue, net	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ ​ 2022 ​ 2021 ​ 2022 ​ 2021 Product revenue, net ​ $ 33,424 ​ $ 12,095 ​ $ 82,585 ​ $ 19,799
Schedule of balances and activity of the product revenue allowance and reserve categories	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contractual ​ Government ​ ​ ​ ​ ​ ​ Adjustments ​ Rebates ​ Returns ​ Total Balance at December 31, 2021 ​ $ 515 ​ $ 719 ​ $ 101 ​ $ 1,335 Current provisions relating to sales in the current year ​ ​ 4,993 ​ ​ 3,011 ​ ​ 227 ​ ​ 8,231 Payments/returns relating to sales in the current year ​ ​ (3,797) ​ ​ (1,659) ​ ​ — ​ ​ (5,456) Payments/returns relating to sales in the prior years ​ ​ (295) ​ ​ (535) ​ ​ — ​ ​ (830) Balance at September 30, 2022 ​ $ 1,416 ​ $ 1,536 ​ $ 328 ​ $ 3,280 ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2022 ​ 2021 Reduction of accounts receivable ​ $ (157) ​ $ (50) Components of other current liabilities ​ ​ 3,437 ​ ​ 1385 Total revenue-related reserves ​ $ 3,280 ​ $ 1,335

Inventory (Tables)

Inventory (Tables)	9 Months Ended
	Sep. 30, 2022
Inventory
Schedule of inventory	​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2022 2021 Raw materials ​ $ — ​ $ — Work-in-process ​ — ​ — Finished Goods ​ ​ 14,621 ​ ​ 3,675 ​ ​ $ 14,621 ​ $ 3,675

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2022
Property and Equipment, Net
Schedule of property and equipment, net	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2022 2021 Furniture, fixtures and vehicles ​ $ 224 ​ $ 62 Computer hardware and software ​ 345 ​ 341 Leasehold improvements ​ ​ 3,931 ​ ​ 3,931 Lab equipment ​ ​ 4,068 ​ ​ 4,249 Construction in progress ​ 32 ​ 166 Total property and equipment ​ ​ 8,600 ​ ​ 8,749 Less: Accumulated depreciation ​ (6,605) ​ (5,915) Total property and equipment, net ​ $ 1,995 ​ $ 2,834

Intangible Assets (Tables)

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2022
Intangible Assets
Schedule of intangible assets, net of accumulated amortization, impairment charges, and adjustments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of September 30, 2022 ​ As of December 31, 2021 ​ ​ Estimated ​ ​ ​ Accumulated ​ ​ ​ ​ ​ Accumulated ​ ​ ​ life Cost Amortization Net ​ Cost Amortization Net Regulatory milestone ​ 20 years ​ $ 20,000 ​ $ 1,500 ​ $ 18,500 ​ $ 20,000 ​ $ 750 ​ $ 19,250 ​ ​ ​ ​ $ 20,000 ​ $ 1,500 ​ $ 18,500 ​ $ 20,000 ​ $ 750 ​ $ 19,250

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2022
Accrued Expenses
Schedule of accrued expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2022 2021 Accrued research and development expenses ​ $ 13,559 ​ $ 24,977 Accrued employee compensation and benefits ​ ​ 8,316 ​ ​ 8,916 Accrued collaboration expenses ​ ​ 4,660 ​ ​ 835 Accrued legal, commercial and professional fees ​ 3,754 ​ 2,933 Other ​ 579 ​ 370 ​ ​ $ 30,868 ​ $ 38,031

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2022
Share-Based Compensation
Schedule of share option activity under the Plans	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ Number of ​ Average ​ ​ Shares ​ Exercise Price Outstanding as of December 31, 2021 9,226,846 ​ $ 14.14 Granted 2,792,460 ​ $ 11.22 Exercised (226,230) ​ $ 5.81 Forfeited (1,468,620) ​ $ 15.59 Outstanding as of September 30, 2022 10,324,456 ​ $ 13.32 Share options exercisable as of September 30, 2022 5,525,898 ​ $ 13.52 Share options unvested as of September 30, 2022 4,798,558 ​ $ 13.10
Schedule of restricted share activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ Number of ​ Grant Date ​ ​ Shares ​ Fair Value Unvested RSUs as of December 31, 2021 ​ 885,021 ​ $ 15.72 Granted ​ 1,318,583 ​ $ 10.71 Vested ​ (229,151) ​ $ 15.79 Forfeited ​ (320,710) ​ $ 14.08 Unvested RSUs as of September 30, 2022 ​ 1,653,743 ​ $ 13.17
Schedule of share-based compensation expense was classified in the consolidated statements of operations and comprehensive loss	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ 2022 2021 ​ 2022 2021 Cost of goods sold ​ $ 164 ​ $ 62 ​ $ 456 ​ $ 101 Research and development expenses ​ ​ 1,532 ​ ​ 1,912 ​ ​ 5,116 ​ ​ 6,469 Selling, general and administrative expenses ​ 4,345 ​ 4,225 ​ 13,176 ​ 12,472 ​ ​ $ 6,041 ​ $ 6,199 ​ $ 18,748 ​ $ 19,042

Out-Licensing Agreements (Table

Out-Licensing Agreements (Tables)	9 Months Ended
	Sep. 30, 2022
Out-licensing Agreements
Schedule of deferred revenue in connection with collaboration agreements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at ​ ​ ​ ​ ​ ​ Balance at End ​ ​ Beginning of Period ​ Additions ​ Deductions ​ of Period Nine Months Ended September 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Huadong rilonacept ​ $ — ​ $ 12,000 ​ $ — ​ $ 12,000 Genentech vixarelimab ​ ​ — ​ ​ 14,290 ​ ​ — ​ ​ 14,290 Deferred revenue ​ $ — ​ $ 26,290 ​ $ — ​ $ 26,290

Earnings (Loss) per Share (Tabl

Earnings (Loss) per Share (Tables)	9 Months Ended
	Sep. 30, 2022
Earnings (Loss) per Share
Schedule of basic and diluted EPS attributable to common shareholders	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ 2022 2021 2022 2021 Numerator: ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) attributable to common shareholders ​ $ 224,093 ​ $ (30,544) ​ $ 178,902 ​ $ (121,591) Denominator: ​ ​ ​ ​ Weighted-average basic shares outstanding ​ 69,445,071 ​ 68,662,673 ​ 69,305,755 ​ 68,444,061 Effect of dilutive securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options to purchase common shares ​ ​ 937,492 ​ ​ — ​ ​ 906,866 ​ ​ — Unvested RSUs ​ ​ 169,455 ​ ​ — ​ ​ 73,823 ​ ​ — Weighted-average diluted shares ​ ​ 70,552,018 ​ ​ 68,662,673 ​ ​ 70,286,444 ​ ​ 68,444,061 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic EPS ​ $ 3.23 ​ $ (0.44) ​ $ 2.58 ​ $ (1.78) Diluted EPS ​ $ 3.18 ​ $ (0.44) ​ $ 2.55 ​ $ (1.78)
Schedule of anti-dilutive securities excluded from the computation of diluted EPS attributable to common shareholders	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ September 30, ​ September 30, ​ 2022 2021 2022 2021 Options to purchase common shares ​ 8,472,937 ​ ​ 9,556,481 ​ ​ 8,880,055 ​ ​ 9,556,481 Unvested RSUs ​ 837,457 ​ ​ 801,154 ​ ​ 1,547,383 ​ ​ 801,154 ​ ​ 9,310,394 ​ ​ 10,357,635 ​ ​ 10,427,438 ​ ​ 10,357,635

Nature of the Business and Ba_2

Nature of the Business and Basis of Presentation (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Liquidity
Accumulated deficit	$ 496,495						$ 496,495		$ 675,397
Net income (loss)	224,093	$ (19,981)	$ (25,210)	$ (30,544)	$ (41,563)	$ (49,484)	178,902	$ (121,591)
Cash provided by operations							17,383	$ (107,414)
Cash, cash equivalents and short-term investments	$ 200,724						$ 200,724

Fair Value of Financial Asset_3

Fair Value of Financial Assets and Liabilities (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022 USD ($) security	Dec. 31, 2021 USD ($) security
Fair Value, Assets Transfers
Fair value of assets transferred from Level 1 to Level 2	$ 0	$ 0
Fair value of assets transferred from Level 2 to Level 1	0	0
Fair value of asset transfer into Level 3	0	0
Fair value of asset transfer out of Level 3	$ 0	$ 0
Number of securities in an unrealized loss position | security	6	11
Securities in unrealized loss position	$ 22,466	$ 49,739
U.S. Treasury Notes
Assets - Fair Value
Short-term investments	24,963	59,731
Short-term investments
Amortized Cost	24,986	59,745
Gross Unrealized Gains		1
Gross Unrealized Losses	(23)	(15)
U.S. Treasury Notes | Short-term Investments
Assets - Fair Value
Short-term investments	24,963	59,731
Short-term investments
Amortized Cost	24,986	59,745
Gross Unrealized Gains		1
Gross Unrealized Losses	(23)	(15)
Fair Value | Recurring basis
Assets - Fair Value
Assets	64,496	154,055
Fair Value | Recurring basis | Money Market Funds
Assets - Fair Value
Cash equivalents	39,533	94,324
Fair Value | Recurring basis | U.S. Treasury Notes
Assets - Fair Value
Short-term investments	24,963	59,731
Fair Value | Recurring basis | Level 1
Assets - Fair Value
Assets	39,533	94,324
Fair Value | Recurring basis | Level 1 | Money Market Funds
Assets - Fair Value
Cash equivalents	39,533	94,324
Fair Value | Recurring basis | Level 2
Assets - Fair Value
Assets	24,963	59,731
Fair Value | Recurring basis | Level 2 | U.S. Treasury Notes
Assets - Fair Value
Short-term investments	$ 24,963	$ 59,731

Product Revenue, Net (Details)

Product Revenue, Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Product revenue
Product revenue, net	$ 99,135	$ 12,095	$ 158,296	$ 19,799
Contractual Adjustments
Balance at beginning of period			515
Current provisions relating to sales in the current year			4,993
Payments/returns relating to sales in the current year			(3,797)
Payments/returns relating to sales in the prior years			(295)
Balance at end of period	1,416		1,416
Government Rebates
Balance at beginning of period			719
Current provisions relating to sales in the current year			3,011
Payments/returns relating to sales in current year			(1,659)
Payments/returns relating to sales in the prior years			(535)
Balance at end of period	1,536		1,536
Returns
Balance at beginning of period			101
Current provision relating sales in the current year			227
Balance at end of period	328		328
Total
Balance at beginning of period			1,335
Current provisions relating to sales in the current year			8,231
Payments/returns relating to sales in the current year			(5,456)
Payments/returns relating to sales in the prior years			(830)
Balance at end of period	3,280		3,280
Product revenue, net
Product revenue
Product revenue, net	$ 33,424	$ 12,095	$ 82,585	$ 19,799

Product Revenue, Net - Revenue

Product Revenue, Net - Revenue Related Reserves in Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Revenue-related reserves
Revenue-related reserves	$ 3,280	$ 1,335
Accounts receivable, net	11,159	3,985
Accounts receivable, net
Revenue-related reserves
Revenue-related reserves	(157)	(50)
Other current liabilities
Revenue-related reserves
Revenue-related reserves	$ 3,437	$ 1,385

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Inventory
Finished goods	$ 14,621	$ 3,675
Total inventory	$ 14,621	$ 3,675

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Property and Equipment, Net
Total property and equipment	$ 8,600		$ 8,600		$ 8,749
Less: Accumulated depreciation	(6,605)		(6,605)		(5,915)
Total property and equipment, net	1,995		1,995		2,834
Depreciation expense	177	$ 373	885	$ 1,079
Furniture, fixtures, and vehicles
Property and Equipment, Net
Total property and equipment	224		224		62
Computer hardware and software
Property and Equipment, Net
Total property and equipment	345		345		341
Leasehold improvements
Property and Equipment, Net
Total property and equipment	3,931		3,931		3,931
Lab equipment
Property and Equipment, Net
Total property and equipment	4,068		4,068		4,249
Construction in progress
Property and Equipment, Net
Total property and equipment	$ 32		$ 32		$ 166

Intangible Assets - Finite-live

Intangible Assets - Finite-lived Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Finite-lived intangible asset
Cost	$ 20,000	$ 20,000
Accumulated Amortization	1,500	750
Net intangible assets	$ 18,500	19,250
Regulatory milestone
Finite-lived intangible asset
Estimated life	20 years
Cost	$ 20,000	20,000
Accumulated Amortization	1,500	750
Net intangible assets	$ 18,500	$ 19,250

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Accrued Expenses
Accrued research and development expenses	$ 13,559	$ 24,977
Accrued employee compensation and benefits	8,316	8,916
Accrued legal and professional fees	3,754	2,933
Accrued collaboration expenses	4,660	835
Other	579	370
Accrued expenses	$ 30,868	$ 38,031

Share Based Compensation (Detai

Share Based Compensation (Details) - shares		9 Months Ended
	Jan. 01, 2022	Sep. 30, 2022	Dec. 31, 2021
Restricted Share Units (RSUs)
Share-based compensation
RSUs Granted		1,318,583
Stock options | Class A common shares
Share-based compensation
Shares outstanding (in shares)		10,324,456	9,226,846
Number of options granted		2,792,460
2018 Plan
Share-based compensation
Number of common shares available for future grant		4,117,546
2018 Plan | Class A common shares | Maximum
Share-based compensation
Additional shares authorized	2,762,416
2015 Plan | Class A common shares
Share-based compensation
Shares outstanding (in shares)		2,029,355
2018 ESPP | Class A common shares
Share-based compensation
Number of common shares available for future grant		604,290
2018 ESPP | Class A common shares | Maximum
Share-based compensation
Additional shares authorized	90,000

Share-Based Compensation - Opti

Share-Based Compensation - Options (Details) - Class A common shares - Stock options	9 Months Ended
	Sep. 30, 2022 $ / shares shares
Number of Shares
Outstanding, beginning of the period | shares	9,226,846
Granted | shares	2,792,460
Exercised | shares	(226,230)
Forfeited | shares	(1,468,620)
Outstanding, end of the period | shares	10,324,456
Options exercisable | shares	5,525,898
Options unvested | shares	4,798,558
Weighted Average Grant Date Fair Value
Outstanding, beginning of the period | $ / shares	$ 14.14
Granted | $ / shares	11.22
Exercised | $ / shares	5.81
Forfeited | $ / shares	15.59
Outstanding, end of the period | $ / shares	13.32
Options exercisable | $ / shares	13.52
Options unvested | $ / shares	$ 13.10

Share-Based Compensation - Rest

Share-Based Compensation - Restricted Shares and RSUs (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share-based compensation
Share-based compensation expense		$ 6,041	$ 6,199	$ 18,748	$ 19,042
Restricted Share Units (RSUs)
Share-based compensation
Share-based compensation expense		$ 1,146	$ 838	$ 2,697	$ 2,868
Number of shares
Beginning of the period				885,021
Granted				1,318,583
Vested				(229,151)
Forfeited				(320,710)
End of the period		1,653,743		1,653,743
Weighted Average Fair Value at Issuance
Beginning of the period				$ 15.72
Granted				10.71
Vested				15.79
Forfeited				14.08
End of the period		$ 13.17		$ 13.17
Time-based RSUs
Share-based compensation
Vesting percentage	25%

Share-Based Compensation - Clas

Share-Based Compensation - Classification of Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share-based compensation
Share-based compensation expense	$ 6,041	$ 6,199	$ 18,748	$ 19,042
Cost of goods sold
Share-based compensation
Share-based compensation expense	164	62	456	101
Research and development expenses
Share-based compensation
Share-based compensation expense	1,532	1,912	5,116	6,469
Selling, general and administrative expenses
Share-based compensation
Share-based compensation expense	4,345	4,225	13,176	12,472
Stock options
Share-based compensation
Total unrecognized compensation cost	40,360		$ 40,360
Expenses expected to be recognized over a weighted average remaining period			2 years 8 months 23 days
Restricted Share Units (RSUs)
Share-based compensation
Share-based compensation expense	1,146	$ 838	$ 2,697	$ 2,868
Total unrecognized compensation cost	$ 17,821		$ 17,821
Expenses expected to be recognized over a weighted average remaining period			3 years 4 months 17 days

Out-Licensing Agreements (Detai

Out-Licensing Agreements (Details) $ in Thousands			3 Months Ended		9 Months Ended
	Aug. 02, 2022 USD ($) item	Feb. 21, 2022 USD ($) item agreement	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)
Collaborative agreements
Product revenue, net			$ 99,135	$ 12,095	$ 158,296	$ 19,799
License and collaboration revenue
Collaborative agreements
Product revenue, net			$ 65,711		75,711
Collaboration Agreements | Huadong rilonacept
Collaborative agreements
Notice period to terminate the agreement		12 months
Collaboration Agreements | Huadong rilonacept
Collaborative agreements
Number of agreements entered into | agreement		2
Upfront payments received		$ 22,000
Term of agreement for royalty payments		12 years
Notice period to terminate the agreement if there is no material development or commercialization activities with respect to the licensed product in China		60 days
Collaboration Agreements | Huadong rilonacept | Minimum
Collaborative agreements
Time period threshold of continuous material development or commercialization activities in China that, if not met, can trigger the right for the Company to terminate the agreement		6 months
Territory License - Rilonacept | Huadong rilonacept
Collaborative agreements
Upfront payments received		$ 12,000
Number of performance obligations in an agreement | item		1
Transaction price					12,000
Territory License - Rilonacept | Huadong rilonacept | Maximum
Collaborative agreements
Payments to be received by the company upon the achievement of specified development, regulatory and sales milestones		$ 70
Territory License - Mavrilimumab | License and collaboration revenue
Collaborative agreements
Product revenue, net					10,000
Territory License - Mavrilimumab | Huadong rilonacept
Collaborative agreements
Upfront payments received		$ 10,000
Number of performance obligations in an agreement | item		2
Transaction price					10,000
Territory License - Mavrilimumab | Huadong rilonacept | Maximum
Collaborative agreements
Payments to be received by the company upon the achievement of specified development, regulatory and sales milestones		$ 576
Worldwide License - Vixarelimab | Genentech
Collaborative agreements
Upfront payments received	$ 80,000
Payments to be received by the company upon delivery of certain materials	20,000
Milestone receipts	$ 600,000
Number of performance obligations in an agreement | item	4
Product revenue, net					$ 65,711
Transaction price	$ 80,000

Out-Licensing Agreements - Defe

Out-Licensing Agreements - Deferred Revenue (Details) $ in Thousands	9 Months Ended	21 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2022 USD ($)
Collaborative agreements
Long-term Deferred Revenue	$ 14,198	$ 14,198
Additions	26,290
Balance at end of period	26,290	26,290
Territory License - Rilonacept | Huadong rilonacept
Collaborative agreements
Long-term Deferred Revenue	12,000	12,000
Additions	12,000
Balance at end of period	12,000	12,000
Territory License - Rilonacept | Huadong rilonacept | License and collaboration revenue
Collaborative agreements
Revenue recognized		0
Worldwide License - Vixarelimab | Genentech
Collaborative agreements
Additions	14,290
Balance at end of period	$ 14,290	$ 14,290

In-license, Acquisition and C_2

In-license, Acquisition and Collaboration Agreements - Biogen Asset Purchase Agreement (Details) - USD ($) $ in Thousands		1 Months Ended		3 Months Ended		9 Months Ended
	Aug. 02, 2022	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
License and Acquisition Agreements
Uncured period which causes termination of the agreement, due to insolvency or bankruptcy or for material breach of the agreement by the other party that remains uncured		90 days
Notice period to terminate the agreement under payment-related breaches		30 days
Research and development				$ 16,485	$ 19,236	$ 51,100	$ 71,864
Maximum
License and Acquisition Agreements
Royalty rate increase (percentage)	1%
Asset Purchase Agreement | Biogen
License and Acquisition Agreements
Remaining milestone payments to be paid upon clinical and regulatory milestone achievement				165,000		165,000
Maximum aggregate obligation to pay insignificant annual maintenance fees as well as clinical and regulatory milestone payments			$ 1,575
Notice period to terminate the agreement			90 days
Uncured period which causes termination of the agreement, due to insolvency or bankruptcy or for material breach of the agreement by the other party that remains uncured			90 days
Notice period to terminate the agreement under payment-related breaches			30 days
Research and development				$ 11	$ 14	$ 45	$ 42
Asset Purchase Agreement | Biogen | Maximum
License and Acquisition Agreements
Milestone payment to be paid upon clinical and regulatory milestone achievement			$ 179,000
Milestone payment to be paid upon net sales milestone achievement			$ 150,000

In-license, Acquisition and C_3

In-license, Acquisition and Collaboration Agreements - Beth Israel Deaconess Medical Center License Agreement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
License and Acquisition Agreements
Research and development	$ 16,485	$ 19,236	$ 51,100	$ 71,864
License Agreement | BIDMC
License and Acquisition Agreements
Research and development	0	$ 0	0	$ 0
License Agreement | BIDMC | Maximum
License and Acquisition Agreements
Milestone payment to be paid upon clinical and regulatory milestone achievement	$ 1,200		$ 1,200

In-license, Acquisition and C_4

In-license, Acquisition and Collaboration Agreements - Regeneron License Agreement (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended			9 Months Ended
	Feb. 28, 2022	Sep. 30, 2017	Sep. 30, 2022	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
License and Acquisition Agreements
Research and development			$ 16,485	$ 19,236		$ 51,100	$ 71,864
Uncured period which causes termination of the agreement, due to insolvency or bankruptcy or for material breach of the agreement by the other party that remains uncured		90 days
Notice period to terminate the agreement under payment-related breaches		30 days
Consecutive suspension of activities period for termination of agreement		12 months
Notice period to terminate the agreement		1 year
Notice period to terminate the agreement if products are having safety concerns		3 months
Intangible asset - Regulatory milestone			20,000			20,000		$ 20,000
Commercial product inventory			14,621			14,621		3,675
Regulatory milestone
License and Acquisition Agreements
Intangible asset - Regulatory milestone			20,000			20,000		20,000
Regeneron | License Agreement
License and Acquisition Agreements
Regulatory milestone payment					$ 20,000
Profit sharing recognized			4,623			16,549	$ 0
Regeneron | License Agreement | Regulatory milestone
License and Acquisition Agreements
Intangible asset - Regulatory milestone			20,000			20,000
Regeneron | License Agreement | Short-term liabilities
License and Acquisition Agreements
Profit sharing recognized	$ 6,000
Regeneron | Clinical Supply Agreement
License and Acquisition Agreements
Commercial product inventory			$ 14,621			$ 14,621		$ 3,675

In-license, Acquisition and C_5

In-license, Acquisition and Collaboration Agreements - MedImmune License Agreement (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended
	Jul. 31, 2020	Sep. 30, 2017	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2017
License and Acquisition Agreements
Notice period to terminate the agreement by both parties for material breaches		90 days
Research and development			$ 16,485	$ 19,236	$ 51,100	$ 71,864
MedImmune | License Agreement
License and Acquisition Agreements
Remaining milestone payments to be paid upon clinical and regulatory milestone achievement			57,500		57,500
Annual net sales excluded from calculation of specified annual net sales thresholds	$ 1,000,000
Maximum percentage of royalty payable on annual net sales of licensed products	20%
Notice period to terminate the agreement by both parties for material breaches	90 days
Notice period to terminate the agreement	90 days
Research and development			$ 0	$ 0	$ 0	$ 0
Minimum | MedImmune | License Agreement
License and Acquisition Agreements
Additional specified annual net sales threshold for additional milestone payment.	$ 1,000,000
Maximum | MedImmune | License Agreement
License and Acquisition Agreements
Milestone payment to be paid upon specified milestone achievements for first two indications							$ 72,500
Milestone payment to be paid upon clinical and regulatory milestone achievement							$ 15,000
Milestone payment to be paid upon specified annual sales milestone achievements	85,000
Additional specified annual net sales threshold for additional milestone payment.	$ 1,100,000

Earnings (Loss) per Share (Deta

Earnings (Loss) per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Numerator:
Net income (loss) attributable to common shareholders	$ 224,093	$ (19,981)	$ (25,210)	$ (30,544)	$ (41,563)	$ (49,484)	$ 178,902	$ (121,591)
Denominator:
Weighted-average basic shares outstanding	69,445,071			68,662,673			69,305,755	68,444,061
Effect of dilutive securities
Weighted-average diluted shares	70,552,018			68,662,673			70,286,444	68,444,061
Basic EPS	$ 3.23			$ (0.44)			$ 2.58	$ (1.78)
Diluted EPS	$ 3.18			$ (0.44)			$ 2.55	$ (1.78)
Options to purchase common shares
Effect of dilutive securities
Effect of dilutive securities	937,492						906,866
Unvested RSUs
Effect of dilutive securities
Effect of dilutive securities	169,455						73,823

Earnings (Loss) per Share - Ant

Earnings (Loss) per Share - Anti-Dilutive Securities (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Anti-dilutive securities excluded from computation of earnings per share
Total, anti-dilutive securities excluded from computation of earnings per share	9,310,394	10,357,635	10,427,438	10,357,635
Options to purchase common shares
Anti-dilutive securities excluded from computation of earnings per share
Total, anti-dilutive securities excluded from computation of earnings per share	8,472,937	9,556,481	8,880,055	9,556,481
Unvested RSUs
Anti-dilutive securities excluded from computation of earnings per share
Total, anti-dilutive securities excluded from computation of earnings per share	837,457	801,154	1,547,383	801,154

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Jul. 31, 2022
Bermuda statutory income tax rate			0%
Net operating loss carryforwards - Bermuda	$ 0	$ 0	$ 0	$ 0
Income tax benefit	177,358	$ 118	174,717	$ (1,106)
Decrease in valuation allowance			185,843
Outside Kiniksa US and Kiniksa UK
Material deferred tax assets	$ 0		$ 0
Kiniksa UK
Tax liabilities incurred					$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands	Sep. 30, 2022 USD ($)
Manufacturing commitments
Non-cancelable purchase commitments	$ 33,019