Kiniksa Pharmaceuticals : Investor Presentation

Corporate Presentation

JANUARY 2023

Forward Looking Statements

This presentation (together with any other statements or information that we may make in connection herewith) contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 with respect to Kiniksa Pharmaceuticals, Ltd. (and its consolidated subsidiaries, collectively, unless context otherwise requires, "Kiniksa," "we," "us" or "our"). In some cases, you can identify forward looking statements by terms such as "may," "will," "should," "expect," "plan," "anticipate," "could," "intend," "goal," "design," "target," "project," "contemplate," "believe," "estimate," "predict," "potential," "strategy," or "continue" or the negative of these terms or other similar expressions, although not all forward-looking statements contain these identifying words. All statements contained in this presentation that do not relate to matters of historical fact should be considered forward-looking statements, including without limitation, statements regarding our strategy; potential value drivers; potential indications; potential market opportunities and competitive position; ongoing, planned and potential clinical trials and other studies; timing and potential impact of clinical data; regulatory and other submissions, applications and approvals; commercial strategy and commercial activities; expected run rate for our cash, cash equivalents and short-term investments; expected funding of our operating plan; financial guidance; third-party collaborations and licensing; and capital allocation.

These statements involve known and unknown risks, uncertainties, and other important factors that may cause our actual results, performance or achievements to be materially different from those expressed or implied by the forward-looking statements, including, without limitation, potential delays or difficulties with our clinical trials; potential inability to demonstrate safety or efficacy or otherwise producing negative, inconclusive or uncompetitive results; potential for changes in final data from preliminary or interim data; potential inability to replicate in later clinical trials positive results from earlier trials and studies; our reliance on third parties for manufacturing and conducting clinical trials, research and other studies; our ability to realize value from our licensing and collaboration arrangements; our ability to source sufficient drug product, as needed, to meet our clinical and commercial requirements; our ability to demonstrate safety and efficacy to the satisfaction of applicable regulatory authorities; potential for applicable regulatory authorities to not accept our filings or to delay or deny approval of any of our product candidates or to require additional data or trials to support any such approval or authorization; delays, difficulty or inability to successfully execute on our commercial strategy for ARCALYST; potential changes in our strategy, clinical trial priority, operating plan and funding requirements; raw materials, important ancillary product and drug substance and/or drug product shortages; substantial new or existing competition; potential impact of the COVID-19 pandemic or any subsequent pandemic, and measures taken in response to such pandemics, on our business and operations as well as the business and operations of our manufacturers, CROs upon whom we rely to conduct our clinical trials, and other third parties with whom we conduct business or otherwise engage, including the FDA and other regulatory authorities; risks related to the ongoing war in Ukraine; risks arising from global political and economic instability; and our ability to attract and retain qualified personnel.

These and the important factors discussed in our filings with the U.S. Securities and Exchange Commission, including under the caption "Risk Factors" contained therein could cause actual results to differ materially from those indicated by the forward-looking statements made in this presentation. These forward-looking statements reflect various assumptions of Kiniksa's management that may or may not prove to be correct. No forward-looking statement is a guarantee of future results, performance, or achievements, and one should avoid placing undue reliance on such statements. Except as otherwise indicated, this presentation speaks as of the date of this presentation. We undertake no obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

This presentation also contains estimates, projections, and/or other information regarding our industry, our business and the markets for certain of our product candidates, including data regarding the estimated size of those markets, and the incidence and prevalence of certain medical conditions. Unless otherwise expressly stated, we obtained this industry, business, market and other data from reports, research surveys, clinical trials, studies and similar data prepared by market research firms and other third parties, from industry, medical and general publications, and from government data and similar sources. Information that is based on estimates, forecasts, projections, market research, or similar methodologies is inherently subject to uncertainties and actual events or circumstances may differ materially from events and circumstances reflected in this information.

ARCALYST is a registered trademark of Regeneron Pharmaceuticals, Inc. All other trademarks are the property of their respective owners.

2

Portfolio of Immune-Modulating Assets

Cardiovascular Franchise

PROGRAM & TARGET PRECLINICALPHASE 1PHASE 2PHASE 3COMMERCIALKINIKSA RIGHTS

ARCALYST®			Worldwide	4
(rilonacept)1,2	RECURRENT PERICARDITIS
(Excluding MENA)
IL-1α & IL-1β
Mavrilimumab3
EVALUATING DEVELOPMENT IN RARE		Worldwide4
GM-CSFRα
CARDIOVASCULAR DISEASES

Autoimmune Franchise

KPL-404

CD40/CD154

RHEUMATOID ARTHRITIS

Worldwide

Vixarelimab

OSMRβ

Roche and Genentech

GLOBAL RIGHTS FOR ALL INDICATIONS 5

1) Approved in the U.S; ARCALYST is also approved for cryopyrin-associated periodic syndromes (CAPS) and deficiency of the interleukin-1 receptor antagonist (DIRA); 2) The FDA granted Breakthrough Therapy designation to ARCALYST for recurrent
pericarditis in 2019; the FDA granted Orphan Drug exclusivity to ARCALYST in March 2021 for the treatment of recurrent pericarditis and reduction in risk of recurrence in adults and pediatric patients 12 years and older. The European Commission	3
granted Orphan Drug designation to ARCALYST for the treatment of idiopathic pericarditis in 2020; 3) Phase 2 clinical trials of mavrilimumab in rheumatoid arthritis and giant cell arteritis achieved their primary and secondary endpoints with statistical
significance; 4) Kiniksa granted Huadong Medicine exclusive rights in the Asia Pacific Region, excluding Japan; 5) In September 2022, Kiniksa granted Genentech and Roche exclusive global rights to develop and commercialize vixarelimab;
IL-1α = interleukin-1α ; IL-1β = interleukin-1β;GM-CSFRα = granulocyte macrophage colony stimulating factor receptor alpha; OSMRβ = oncostatin M receptor beta; MENA = Middle East and North Africa

Executed Across Commercial and Clinical-Stage Portfolio in 2022

Setting the stage for continued success in 2023 and beyond

2022 - Consistent Execution

2023

Emerging leader in immune-modulating therapies

Strong commercial launch of ARCALYST in recurrent pericarditis

Multiple ascending dose portion (Cohort 1 & 2) of KPL-404 Phase 2 trial in rheumatoid arthritis enrolled

License agreement with Genentech for global rights to vixarelimab

Strategic collaboration with Huadong Medicine for Asia Pacific Region

ARCALYST revenue growth opportunity by continuing to broaden reach with recurrent pericarditis physicians and patients through focus on high decile physicians

Enroll patients in proof-of-concept portion (Cohort 3) of Phase 2 trial of KPL-404 in rheumatoid arthritis

Continue to evaluate potential value-creating business development opportunities through in-licensing and out-licensing

Remain well capitalized

• Year end 2022 ~$190.4M cash reserves expected to fund current operating plan into at least 20251

Continue to help patients and build value

4

1) As used herein the term, "Cash Reserves" means our cash, cash equivalents and short-term investments (unaudited) as of December 31, 2022

Partnership with Huadong Medicine Gives Kiniksa Opportunity to Expand Footprint into Asia Pacific Region (Excluding Japan)

In February 2022, Kiniksa announced a strategic collaboration with Huadong to develop and commercialize ARCALYST and mavrilimumab in Greater China, South Korea, Australia and 18 other countries, excluding Japan

Kiniksa received a $22M upfront payment and is eligible to receive up to approximately $640M in specified development, regulatory and sales-based milestone along with tiered royalty payments

• Huadong has filed a Biologic License Application for CAPS in mainland China and if approved, Kiniksa would receive additional non-dilutive capital.

Collaboration provided non-dilutive capital, cost-sharing, and additional resources to help accelerate development and commercialization efforts

5