David Kerstein Form 3 Theseus Pharmaceuticals / David Kerstein ownership change

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person^*

Kerstein David

(Last) (First) (Middle)

C/O THESEUS PHARMACEUTICALS, INC.

245 MAIN STREET

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
10/06/2021

3. Issuer Name and Ticker or Trading Symbol
Theseus Pharmaceuticals, Inc. [ THRX ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	10% Owner
X	Officer (give title below)	Other (specify below)
Chief Medical Officer

5. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (right to buy)	(1)	12/23/2030	Common Stock	293,068	0.3175	D
Stock Option (right to buy)	(2)	03/22/2031	Common Stock	14,426	4.0347	D
Stock Option (right to buy)	(3)	05/26/2031	Common Stock	24,620	4.0347	D
Stock Option (right to buy)	(4)	08/26/2031	Common Stock	48,342	9.9876	D

Explanation of Responses:

1. The options are immediately exercisable in full due to early exercise rights, subject to the issuer's right of repurchase. The options are subject to a service-based vesting requirement, which shall be satisfied over a four-year period with 25% of the options vesting on October 26, 2021 and 1/48th of the options vesting monthly thereafter, subject to the Reporting Person's continuous service with the issuer

2. The options are immediately exercisable in full due to early exercise rights, subject to the issuer's right of repurchase. The options are subject to a service-based vesting requirement, which shall be satisfied over a four-year period with 25% of the options vesting on October 26, 2021 and 1/48th of the options vesting monthly thereafter, subject to the Reporting Person's continuous service with the issuer.

3. The options are subject to a service-based vesting requirement, which shall be satisfied over a four-year period with 1/48th of the options vesting monthly after May 27, 2021, subject to the Reporting Person's continuous service with the issuer.

4. The options are subject to a service-based vesting requirement, which shall be satisfied over a four-year period with 25% of the options vesting on August 27, 2022 and 1/48th of the options vesting monthly thereafter, subject to the Reporting Person's continuous service with the issuer.

Remarks:

	/s/ Bradford Dahms - Attorney-in-Fact	10/06/2021
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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