# EDGAR Filing Document

**Accession Number:** 0001662244
**File Stem:** 0001209191-23-007528
**Filing Date:** 2023-2
**Character Count:** 9939
**Document Hash:** 6ce63eb1efe867f24b442e2331b5308c
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001209191-23-007528.hdr.sgml**: 20230207

**ACCESSION NUMBER**: 0001209191-23-007528

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20211220

**FILED AS OF DATE**: 20230207

**DATE AS OF CHANGE**: 20230207

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Gaiero David G
- **CENTRAL INDEX KEY:** 0001799784

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-40499
- **FILM NUMBER:** 23595587

**MAIL ADDRESS:**
- **STREET 1:** 733 CONCORD AVENUE
- **STREET 2:** C/O WAVE LIFE SCIENCES USA, INC.
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02138
**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

```

                             LIMITED POWER OF ATTORNEY

	The undersigned hereby constitutes and appoints Markus Renschler and Adam
Veness, and each of them individually, with full power of substitution, as the
undersigned's true and lawful attorney-in-fact to:

(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.

	The undersigned hereby grants to each such attorney-in-fact full power and
authority to do and perform any and every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of any of the rights and powers
herein granted, as fully to all intents and purposes as the undersigned might or
could do if personally present, with full power of substitution or revocation,
hereby ratifying and confirming all that each such attorney-in-fact, or each
such attorney-in-fact's substitute or substitutes, shall lawfully do or cause to
be done by virtue of this power of attorney and the rights and powers herein
granted.  The undersigned acknowledges that each foregoing attorney-in-fact, in
serving in such capacity at the request of the undersigned, are not assuming,
nor is the Company assuming, any of the undersigned's responsibilities to comply
with Section 16 of the Securities Exchange Act of 1934, as amended.

	This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4, 5, and any Schedules 13D
or 13G with respect to the undersigned's holdings of and transactions in
securities issued by the Company, unless earlier revoked by the undersigned in a
signed writing delivered to each foregoing attorney-in-fact.

                  [Remainder of page intentionally left blank]

	IN WITNESS WHEREOF, the undersigned has caused this 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>Gaiero David G<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>2021-12-20 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [ ] 10% Owner<br>[X] Officer (give title below) [ ] Other (specify below)<br>_Chief Financial Officer_ |
| **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 |
| Common Stock | 2021-12-20 |  | M |  | 4100 | A | 1.68<sup>(1)</sup> | 4100 | D |  |

---

## 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) | 1.68<sup>(1)</sup> | 2021-12-20 |  | M |  |  | 4100 | <sup>(2)</sup> | 2030-12-10 | Common Stock | 4100 | $0.00 | 73639 | D |  |

---

### Footnotes:

(1) Due to rounding in connection with the Issuer's reverse stock split during its initial public offering, the exercise price for this option was immaterially incorrect as reported on the Reporting Person's Form 3 filing on June 17, 2021, and has been corrected in this Form 4.

(2) The option vested as to 25% of the underlying shares of common stock on December 7, 2021, the first anniversary of the vesting commencement date, and vests 1/48th of the underlying shares thereafter on each subsequent monthly anniversary of the vesting commencement date until the option is fully vested, subject to the Reporting Person's continued employment with the Issuer through the applicable vesting date.

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

**Signature:** /s/ Adam M. Veness, as attorney-in-fact for David Gaiero  
**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.**