# EDGAR Filing Document

**Accession Number:** 0001662244
**File Stem:** 0001209191-23-007547
**Filing Date:** 2023-2
**Character Count:** 8969
**Document Hash:** e9d7d06304d8ca1e38814b415f67ecba
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001209191-23-007547.hdr.sgml**: 20230207

**ACCESSION NUMBER**: 0001209191-23-007547

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20230203

**FILED AS OF DATE**: 20230207

**DATE AS OF CHANGE**: 20230207

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Molineaux Susan
- **CENTRAL INDEX KEY:** 0001553389

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-40499
- **FILM NUMBER:** 23595682

**MAIL ADDRESS:**
- **STREET 1:** C/O CALITHERA BIOSCIENCES, INC.
- **STREET 2:** 343 OYSTER POINT BLVD., SUITE 200
- **CITY:** SOUTH SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94080
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Cyteir Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001662244
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **IRS NUMBER:** 455429901
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 128 SPRING STREET
- **STREET 2:** BUILDING A, SUITE 510
- **CITY:** LEXINGTON
- **STATE:** MA
- **ZIP:** 02421
- **BUSINESS PHONE:** 857-285-4140

**MAIL ADDRESS:**
- **STREET 1:** 128 SPRING STREET
- **STREET 2:** BUILDING A, SUITE 510
- **CITY:** LEXINGTON
- **STATE:** MA
- **ZIP:** 02421

## Ex-24

```

                             SUBSTITUTE POWER OF ATTORNEY

	Pursuant to the Limited Power of Attorney of Susan Molineaux, Ph.D. (the "Power
of Attorney"), dated May 24, 2021 and filed with the Securities and Exchange
Commission, the undersigned has been constituted and appointed true and lawful
attorney-in-fact, with full power of substitution, to, on behalf of Dr.
Molineaux:

(1)	prepare, execute in the undersigned's name and on the undersigned's behalf,
and submit to the U.S. Securities and Exchange Commission (the "SEC") a Form ID,
including amendments thereto, and any other documents necessary or appropriate
to obtain codes and passwords enabling the undersigned to make electronic
filings with the SEC of reports required by Section 16(a) of the Securities
Exchange Act of 1934, as amended, or any rule or regulation of the SEC;

(2)	execute for and on behalf of the undersigned, in the undersigned's capacity
as officer and/or director of Cyteir Therapeutics, Inc. (the "Company"), Forms
3, 4, 5 and any Schedules 13D or 13G in accordance with Section 16(a) of the
Securities Exchange Act of 1934, as amended, and the rules thereunder;

(3)	do and perform any and all acts for and on behalf of the undersigned that
may be necessary or desirable to complete and execute any such Form 3, 4, or 5
or Schedule 13D or 13G, complete and execute any amendment or amendments
thereto, and timely file such form with the SEC and any stock exchange or
similar authority; and

(4)	take any other action of any type whatsoever in connection with the
foregoing that, in the opinion of each such attorney-in-fact, may be of benefit
to, in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by each such attorney-in-fact on behalf
of the undersigned pursuant to this Power of Attorney shall be in such form and
shall contain such terms and conditions as each such attorney-in-fact may
approve in each such attorney-in-fact's discretion.

	Pursuant to the powers granted to the undersigned in the Power of Attorney, the
undersigned hereby constitutes and appoints Adam Veness as a substitute to the
undersigned attorney-in-fact, with full power of substitution, and with full
power and authority to do and perform every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of the rights and powers granted
to the undersigned in said Power of Attorney.  For the avoidance of doubt, the
foregoing appointment shall not serve as a revocation of the powers granted to
the undersigned himself in the Power of Attorney.

	This Substitute Power of Attorney shall remain in full force and effect unless
and until revoked by the undersigned.

                  [Remainder of page intentionally left blank]

	IN WITNESS WHEREOF, the undersigned has caused this Substitute Power of
Attorney to be executed as of this 7th day of February, 2023.

		/s/ David Gaiero
		-------------------
		David Gaiero

```

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

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

[ ] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Molineaux Susan<br><sub>(Last) (First) (Middle)</sub><br>C/O CYTEIR THERAPEUTICS, INC.<br>128 SPRING ST, BUILDING A, SUITE 510<br><sub>(Street)</sub><br>LEXINGTON, MA 02421<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2023-02-03 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [ ] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Cyteir Therapeutics, Inc. [ CYT ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
|  |  |  |  |  |  |  |  |  |  |  |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| Stock Option (Right to Buy) | $1.69 | 2023-02-03 |  | A |  | 14150 |  | <sup>(1)</sup> | 2033-02-03 | Common Stock | 14150 | $0.00 | 14150 | D |  |

---

### Footnotes:

(1) The shares of common stock underlying this stock option award vest in full on February 3, 2024, subject to the Reporting Person's continued service to the board of directors of the Company through the applicable vesting date.

**Remarks:**
Exhibit List: Exhibit 24 - Power of Attorney

**Signature:** /s/ Adam M. Veness, as attorney-in-fact for Susan Molineaux  
**Date:** 2023-02-07

### Remarks:

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 4 (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.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**