Statement of Changes in Beneficial Ownership (4)

FORM 4 [ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES
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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person ^* BAKER BROS. ADVISORS LP	2. Issuer Name and Ticker or Trading Symbol Kiniksa Pharmaceuticals, Ltd. [ KNSA ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below)
(Last) (First) (Middle) 860 WASHINGTON STREET, 3RD FLOOR	3. Date of Earliest Transaction (MM/DD/YYYY) 6/29/2021
(Street) NEW YORK, NY 10014 (City) (State) (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) ___ Form filed by One Reporting Person _ X _ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. Code (Instr. 8)		4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)

*Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)*
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)			11. Nature of Indirect Beneficial Ownership (Instr. 4)
Non-Qualified Share Option (right to buy)	$14.33 ⁽¹⁾	6/29/2021		A		66474		⁽¹⁾	6/28/2031 ⁽¹⁾	Class A Common Shares	66474	$0	66474	I	See Footnotes ⁽¹⁾⁽²⁾⁽³⁾⁽⁴⁾

Explanation of Responses:
(1)	33,237 non-qualified share options ("Share Options") exercisable solely into Class A common shares ("Class A Common Shares") of Kiniksa Pharmaceuticals, Ltd. (the "Issuer") each granted to Felix J. Baker, a managing member of Baker Bros. Advisors (GP) LLC (the "Adviser GP") and Dr. Stephen R. Biggar, a full time employee of Baker Bros. Advisors LP (the "Adviser") on June 29, 2021, pursuant to the Issuer's 2018 Incentive Award Plan. The Share Options with a strike price of $14.33 vest in 12 equal monthly installments and expire 10 years from the date of grant. Felix J. Baker and Dr. Biggar serve on the board of directors of the Issuer (the "Board") as representatives of 667, L.P. ("667") and Baker Brothers Life Sciences, L.P. ("Life Sciences", and together with 667, the "Funds").
(2)	Pursuant to the policies of the Adviser, Felix J. Baker and Dr. Biggar do not have a right to any of the Issuer's securities issued as part of their service on the Board and the Funds are entitled to an indirect proportionate pecuniary interest in the securities. The Funds each own an indirect proportionate pecuniary interest in the Share Options. Solely as a result of their ownership interest in (i) the general partners of the Funds and (ii) the Funds, Felix J. Baker and Julian C. Baker may be deemed to have an indirect pecuniary interest in the Share Options and any Class A Common Shares resulting from the exercise of Share Options (i.e. no direct pecuniary interest).
(3)	The Adviser serves as the investment adviser to the Funds. In connection with the services provided by the Adviser, the Adviser receives an asset-based management fee that does not confer any pecuniary interest in the securities held by the Funds. The Adviser GP is the Adviser's sole general partner. Julian C. Baker and Felix J. Baker are managing members of the Adviser GP. The Adviser has complete and unlimited discretion and authority with respect to the investment and voting power of the securities held by the Funds. The general partners of the Funds relinquished to the Adviser all discretion and authority with respect to the investment and voting power of the securities held by the Funds. The Adviser has voting and dispositive power over the Share Options and any Class A Common Shares received as a result of the exercise of Share Options.
(4)	Julian C. Baker, Felix J. Baker, the Adviser GP and the Adviser disclaim beneficial ownership of the securities held directly by the Funds except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that any of Julian C. Baker, Felix J. Baker, the Adviser GP or the Adviser is a beneficial owner of such securities for purposes of Section 16 or any other purpose.

Remarks:
Felix J. Baker, a managing member of Baker Bros. Advisors (GP) LLC and Dr. Stephen R. Biggar, a full-time employee of Baker Bros. Advisors LP are directors of Kiniksa Pharmaceuticals, Ltd. (the "Issuer"). By virtue of their representation on the board of directors of the Issuer, for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, the reporting persons are deemed directors by deputization of the Issuer.

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
BAKER BROS. ADVISORS LP 860 WASHINGTON STREET 3RD FLOOR NEW YORK, NY 10014	X
667, L.P. 860 WASHINGTON STREET, 3RD FLOOR NEW YORK, NY 10014	X
Baker Bros. Advisors (GP) LLC 860 WASHINGTON STREET 3RD FLOOR NEW YORK, NY 10014	X
Baker Brothers Life Sciences LP 860 WASHINGTON STREET 3RD FLOOR NEW YORK, NY 10014	X
BAKER FELIX 860 WASHINGTON STREET 3RD FLOOR NEW YORK, NY 10014	X
BAKER JULIAN 860 WASHINGTON STREET, 3RD FLOOR NEW YORK, NY 10014	X

Signatures
By: Baker Bros. Advisors LP, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing		7/1/2021
^**Signature of Reporting Person		Date
Baker Bros. Advisors LP, Mgmt. Co. and Inv. Adviser to 667, L.P., pursuant to authority granted by Baker Biotech Capital, L.P., GP to 667, L.P. Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing		7/1/2021
^**Signature of Reporting Person		Date
By: Baker Bros. Advisors (GP) LLC, Name: Scott L. Lessing, Title: President /s/ Scott L. Lessing		7/1/2021
^**Signature of Reporting Person		Date
Baker Bros. Advisors LP, Mgmt. Co. and Inv. Adviser to BAKER BROTHERS LIFE SCIENCES, L.P., pursuant to authority granted by Baker Brothers Life Sciences Capital, L.P., GP to Baker Brothers Life Sciences, L.P., Name: Scott L. Lessing, Title: President /s/		7/1/2021
^**Signature of Reporting Person		Date
/s/ Felix J. Baker		7/1/2021
^**Signature of Reporting Person		Date
/s/ Julian C. Baker		7/1/2021
^**Signature of Reporting Person		Date