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 ^* GADICKE ANSBERT	2. Issuer Name and Ticker or Trading Symbol iTeos Therapeutics, Inc. [ ITOS ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below)
(Last) (First) (Middle) C/O MPM CAPITAL, 450 KENDALL STREET	3. Date of Earliest Transaction (MM/DD/YYYY) 9/23/2021
(Street) CAMBRIDGE, MA 02142 (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)
Common Stock	9/23/2021		S⁽¹⁾		60600 ⁽²⁾⁽³⁾	D	$27.96 ⁽⁴⁾	5458833	I	See Footnote ⁽⁵⁾
Common Stock	9/23/2021		S⁽¹⁾		1200 ⁽⁶⁾	D	$28.38 ⁽⁷⁾	5457633	I	See Footnote ⁽⁸⁾
Common Stock	9/24/2021		S⁽¹⁾		8221 ⁽⁹⁾	D	$27.81 ⁽¹⁰⁾	5449412	I	See Footnote ⁽¹¹⁾
Common Stock	9/27/2021		S⁽¹⁾		19455 ⁽¹²⁾	D	$27.09 ⁽¹³⁾	5429957	I	See Footnote ⁽¹⁴⁾

*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)

Explanation of Responses:
(1)	Transaction effected pursuant to a plan established pursuant to Rule 10b5-1.
(2)	The shares were sold as follows: 21,575 by MPM BioVentures 2014, L.P. ("BV 2014"), 743 by MPM Asset Management Investors BV2014 LLC ("AM BV2014"), 13,626 by MPM BioVentures 2018, L.P. ("BV 2018"), 269 by MPM Asset Management Investors BV2018 LLC ("AM BV2018") and 24,387 by UBS Oncology Impact Fund L.P. ("UBS Oncology"). MPM BioVentures 2014 GP LLC and MPM BioVentures 2014 LLC ("BV 2014 LLC") are the direct and indirect general partners of BV 2014 and BV 2014(B). BV 2014 LLC is the manager of AM BV2014. MPM BioVentures 2018 GP LLC and MPM BioVentures 2018 LLC ("BV 2018 LLC") are the direct and indirect general partners of BV 2018 and BV 2018(B). BV 2018 LLC is the manager of AM BV2018. Ansbert Gadicke is a managing director of BV 2014 LLC and BV 2018 LLC.
(3)	BioImpact Capital LLC ("BioImpact") is the General Partner of Oncology Impact Fund (Cayman) Management L.P., the General Partner of UBS Oncology Impact Fund, L.P. Ansbert Gadicke is a managing partner of BioImpact. Each of the Reporting Persons disclaims beneficial ownership of the securities herein except to the extent of his or its respective pecuniary interest therein, if any.
(4)	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $27.25 to $28.24 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
(5)	The shares are held as follows: 1,885,806 by BV 2014, 107,713 by MPM BioVentures 2014(B), L.P. ("BV 2014(B)"), 64,908 by AM BV2014, 1,191,035 by BV 2018, 54,213 by MPM BioVentures 2018(B), L.P. ("BV 2018(B)"), 23,505 by AM BV2018 and 2,131,653 by UBS Oncology. Each of the Reporting Persons disclaims beneficial ownership of the securities herein except to the extent of his or its respective pecuniary interest therein, if any.
(6)	The shares were sold as follows: 427 by BV 2014, 15 by AM BV2014, 270 by BV 2018, 5 by AM BV2018 and 483 by UBS Oncology.
(7)	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $28.26 to $28.46 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
(8)	The shares are held as follows: 1,885,379 by BV 2014, 107,713 by BV 2014(B), 64,893 by AM BV2014, 1,190,765 by BV 2018, 54,213 by BV 2018(B), 23,500 by AM BV2018 and 2,131,170 by UBS Oncology. Each of the Reporting Persons disclaims beneficial ownership of the securities herein except to the extent of his or its respective pecuniary interest therein, if any.
(9)	The shares were sold as follows: 2,927 by BV 2014, 101 by AM BV2014, 1,849 by BV 2018, 36 by AM BV2018 and 3,308 by UBS Oncology.
(10)	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $27.39 to $28.26 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
(11)	The shares are held as follows: 1,882,452 by BV 2014, 107,713 by BV 2014(B), 64,792 by AM BV2014, 1,188,916 by BV 2018, 54,213 by BV 2018(B), 23,464 by AM BV2018 and 2,127,862 by UBS Oncology. Each of the Reporting Persons disclaims beneficial ownership of the securities herein except to the extent of his or its respective pecuniary interest therein, if any.
(12)	The shares were sold as follows: 6,926 by BV 2014, 238 by AM BV2014, 4,375 by BV 2018, 86 by AM BV2018 and 7,830 by UBS Oncology.
(13)	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $26.95 to $27.40 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
(14)	The shares are held as follows: 1,875,526 by BV 2014, 107,713 by BV 2014(B), 64,554 by AM BV2014, 1,184,541 by BV 2018, 54,213 by BV 2018(B), 23,378 by AM BV2018 and 2,120,032 by UBS Oncology. Each of the Reporting Persons disclaims beneficial ownership of the securities herein except to the extent of his or its respective pecuniary interest therein, if any.

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
GADICKE ANSBERT C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE, MA 02142		X
UBS Oncology Impact Fund L.P. C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE, MA 02142		X
BioImpact Capital LLC C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE, MA 02142		X
Oncology Impact Fund (Cayman) Management L.P. C/O MPM CAPITAL 450 KENDALL STREET CAMBRIDGE, MA 02142		X

Signatures
/s/ Ansbert Gadicke		9/27/2021
^**Signature of Reporting Person		Date
/s/ Ansbert Gadicke, managing partner of BioImpact Capital LLC, the general partner of Oncology Impact Fund (Cayman) Management L.P., the general partner of UBS Oncology Impact Fund L.P		9/27/2021
^**Signature of Reporting Person		Date
/s/ Ansbert Gadicke, managing partner of BioImpact Capital LLC		9/27/2021
^**Signature of Reporting Person		Date
/s/ Ansbert Gadicke, managing partner of BioImpact Capital LLC, the general partner of Oncology Impact Fund (Cayman) Management L.P.		9/27/2021
^**Signature of Reporting Person		Date