Kiniksa Reports First Quarter 2020 Financial Results and Highlights Recent Corporate and Pipeline Activity - Financial guidance and clinical timelines for rilonacept, mavrilimumab, vixarelimab and KPL-404 remain intact a

Reports First Quarter 2020 Financial Results and Highlights Recent Corporate and Pipeline Activity

- April 28, 2020 - Kiniksa Pharmaceuticals, Ltd. (Nasdaq: KNSA) ("Kiniksa"),

a biopharmaceutical company focused on discovering, acquiring, developing and commercializing therapeutic medicines for patients

with significant unmet medical need, today reported first quarter 2020 financial results and highlighted recent corporate and

"Kiniksa continued to advance its clinical-stage pipeline

in the first quarter despite the COVID-19 pandemic," said Sanj K. Patel, Chief Executive Officer and Chairman of the Board

of Kiniksa. "Our projected cash runway extends into the second half of 2021, and our clinical timelines remain on track.

Our evaluation of mavrilimumab in COVID-19 pneumonia and hyperinflammation is progressing, and we continue to expect further clinical

data from vixarelimab in the first half of 2020 as well as data from rilonacept, mavrilimumab and KPL-404 in the second half of

Rilonacept (IL-1 and IL-1 cytokine trap)

Mavrilimumab (monoclonal antibody inhibitor targeting GM-CSFR )

Vixarelimab (monoclonal antibody inhibitor of signaling through

KPL-404 (monoclonal antibody inhibitor of signaling between

1 The treatment protocol with the investigational

drug mavrilimumab was conducted by Professor Lorenzo Dagna, MD, FACP, Head, Unit of Immunology, Rheumatology, Allergy and Rare

Diseases IRCCS San Raffaele Scientific Institute and Vita-Salute San Raffaele University in Milan, Italy within a COVID-19 Program

directed by Professor Alberto Zangrillo, Head of Department of Anesthesia and Intensive Care of the Scientific Institute San Raffaele

Hospital and Professor in Anesthesiology and Intensive Care, Universit Vita-Salute San Raffaele.

Kiniksa is a biopharmaceutical company focused on discovering,

acquiring, developing and commercializing therapeutic medicines for patients suffering from debilitating diseases with significant

unmet medical need. Kiniksa's clinical-stage product candidates, rilonacept, mavrilimumab, vixarelimab and KPL-404, are

based on strong biologic rationale or validated mechanisms, target underserved conditions and offer the potential for differentiation.

These pipeline assets are designed to modulate immunological signaling pathways that are implicated across a spectrum of diseases.

For more information, please visit www.kiniksa.com.

Rilonacept is a weekly, subcutaneously-injected, recombinant

fusion protein that blocks interleukin-1 alpha (IL-1 ) and interleukin-1 beta (IL-1 ) signaling. Rilonacept was discovered

and developed by Regeneron Pharmaceuticals, Inc. (Regeneron) and is approved by the FDA under the brand name ARCALYST

for the treatment of Cryopyrin-Associated Periodic Syndromes (CAPS), which includes Familial Cold Autoinflammatory Syndrome and

Muckle-Wells Syndrome. Interleukin-1 (IL-1) blockade may interfere with immune response to infections. Serious, life-threatening

infections have been reported in patients taking ARCALYST. ARCALYST should be discontinued if a patient develops a serious infection.

Taking ARCALYST with tumor necrosis factor (TNF) inhibitors is not recommended because this may increase the risk of serious infections.

Kiniksa exclusively licensed rilonacept from Regeneron for recurrent pericarditis and certain other indications. Rilonacept in

recurrent pericarditis is an investigational drug. The FDA has granted Breakthrough Therapy designation to rilonacept for recurrent

Mavrilimumab is an investigational fully-human monoclonal antibody

that is designed to antagonize GM-CSF signaling by binding to the alpha subunit of the GM-CSF receptor (GM-CSFR ). Kiniksa's

lead indication for mavrilimumab is GCA, an inflammatory disease of medium-to-large arteries. Mavrilimumab was dosed in over 550

patients with rheumatoid arthritis through Phase 2b clinical studies in Europe and achieved prospectively-defined primary endpoints

of efficacy and safety. Additionally, Kiniksa and Kite have a clinical collaboration to evaluate mavrilimumab in combination with

Yescarta (axicabtagene ciloleucel) in patients with relapsed or refractory large B-cell lymphoma.

About Vixarelimab (KPL-716)

Vixarelimab is an investigational fully-human monoclonal antibody

that targets oncostatin M receptor beta (OSMR ), which mediates signaling of interleukin-31 (IL-31) and oncostatin M (OSM),

two key cytokines implicated in pruritus, inflammation and fibrosis. Kiniksa believes vixarelimab to be the only monoclonal antibody

in development that targets both pathways simultaneously.

KPL-404 is an investigational humanized monoclonal

antibody that is designed to inhibit CD40-CD40 ligand (CD40L) interaction, a key T-cell co-stimulatory signal critical for

B-cell maturation and immunoglobulin class switching. Kiniksa believes disrupting CD40-CD40L interaction is an attractive

approach for blocking T-cell mediated, B-cell driven responses, drivers of multiple autoimmune disease pathologies such as

rheumatoid arthritis, Sjogren's syndrome, Graves' disease, systemic lupus erythematosus and solid organ

Forward-Looking Statements

This press release contains forward-looking statements within

the meaning of the Private Securities Litigation Reform Act of 1995. In some cases, you can identify forward looking statements

by terms such as "may," "will," "should," "expect," "plan," "anticipate,"

"could," "intend," "target," "project," "contemplate," "believe,"

"estimate," "predict," "potential" 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 press release that do not relate to matters of historical fact should be considered forward-looking statements, including

without limitation, statements regarding: our expectations for fiscal year 2020 data readouts; our beliefs about the mechanisms

of action of our product candidates and potential impact of their approach; planned and preparations for potential clinical trials,

including a potential registrational development program for mavrilimumab in COVID-19 pneumonia and hyperinflammation and a Phase

2 trial evaluating the investigational combination of Yescarta (axicabtagene ciloleucel) and mavrilimumab in relapsed

or refractory large B-cell lymphoma, and the timing thereof; plans and timing to report or present preliminary, interim and final

top-line or other clinical trial data; and our projected timeframe for funding our operating plan with current cash, cash equivalents

and short-term investments.

These forward-looking statements are based on

management's current plans, estimates or expectations. These statements are neither promises nor guarantees, but

involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or

achievements to be materially different from any future results, performance or achievements expressed or implied by the

forward-looking statements, including without limitation, the following: potential delays or difficulty in enrollment of

patients in, and activation or continuation of sites for, our clinical trials; potential complications in coordinating among

requirements, regulations and guidelines of regulatory authorities across a number of jurisdictions for our global clinical

trials; potential amendments to our clinical trial protocols initiated by us or required by regulatory authorities; potential

delays or difficulty in completing our clinical trials, including as a result of our clinical trial design; potential for low

accrual of events in our clinical trials; potential undesirable side effects caused by our product candidates; our potential

inability to demonstrate safety and efficacy to the satisfaction of applicable regulatory authorities or otherwise producing

negative, inconclusive or commercially uncompetitive results; potential for changes between final data and any preliminary

and interim top-line or other data we announce; impact of additional data from us or other companies; our potential inability

to replicate in later clinical trials positive results from our earlier pre-clinical and clinical trials; drug substance

and/or drug product shortages; our reliance on third parties as the sole source of supply of the drug substance and drug

products used in our product candidates; our reliance on third parties to conduct our research, pre-clinical studies,

clinical trials, and other trials for our product candidates; changes in our operating plan and funding requirements;

substantial existing or new competition; potential impact of the COVID-19 pandemic, and measures taken in response to the

pandemic, 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; and our ability to attract and retain qualified personnel.

These and other important factors discussed under the caption

"Risk Factors" in our Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on March 5,

2020 and our other reports subsequently filed with the SEC could cause actual results to differ materially from those indicated

by the forward-looking statements made in this press release. Any such forward-looking statements represent management's

plans, estimates, or expectations as of the date of this press release. While we may elect to update such forward-looking statements

at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change. These forward-looking

statements should not be relied upon as representing our views as of any date subsequent to the date of this press release.

ARCALYST is a registered trademark of Regeneron

Pharmaceuticals, Inc. and Yescarta is a registered trademark of Gilead Sciences, Inc., or its related companies.

Every Second Counts!

Kiniksa Investor and Media Contact

KINIKSA PHARMACEUTICALS, LTD.

CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except share and per share amounts)