# EDGAR Filing Document

**Accession Number:** 0001829802
**File Stem:** 0000950170-23-010649
**Filing Date:** 2023-3
**Character Count:** 24946
**Document Hash:** 01f3510e207a60f2b7bf076fcf1f9872
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000950170-23-010649.hdr.sgml**: 20230329

**ACCESSION NUMBER**: 0000950170-23-010649

**CONFORMED SUBMISSION TYPE**: S-8

**PUBLIC DOCUMENT COUNT**: 6

**FILED AS OF DATE**: 20230329

**DATE AS OF CHANGE**: 20230329

**EFFECTIVENESS DATE**: 20230329

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Sensei Biotherapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001829802
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **IRS NUMBER:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** S-8
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-270946
- **FILM NUMBER:** 23775999

**BUSINESS ADDRESS:**
- **STREET 1:** 620 PROFESSIONAL DRIVE
- **CITY:** GAITHERSBURG
- **STATE:** MD
- **ZIP:** 20879
- **BUSINESS PHONE:** (240) 243-8000

**MAIL ADDRESS:**
- **STREET 1:** 620 PROFESSIONAL DRIVE
- **CITY:** GAITHERSBURG
- **STATE:** MD
- **ZIP:** 20879

**As filed with the U.S. Securities and Exchange Commission on March 29, 2023**

Registration No. 333-

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

Washington, D.C. 20549

_____________________________________

**FORM S-8**

**REGISTRATION STATEMENT**

UNDER

THE SECURITIES ACT OF 1933

_____________________________________

**SENSEI BIOTHERAPEUTICS, INC.**

(Exact name of registrant as specified in its charter)

_____________________________________

---

| | |
|:---|:---|
| &nbsp;&nbsp;**Delaware** | &nbsp;&nbsp;**83-1863385** |
| &nbsp;&nbsp;(State or other jurisdiction of<br>Incorporation or organization) | &nbsp;&nbsp;(I.R.S. Employer <br>Identification No.) |

---

**1405 Research Blvd, Suite 125<br>Rockville, MD 20850**

**(Address of principal executive offices) (Zip code)**

_____________________________________

**2021 Equity Incentive Plan**

**2021 Employee Stock Purchase Plan**

**(Full title of the plan)**

_____________________________________

**John Celebi**

**President and Chief Executive Officer**

**Sensei Biotherapeutics, Inc.**

**1405 Research Blvd, Suite 125,<br>Rockville, MD 20850**

**(240) 243-8000**

**(Name and address of agent for service) (Telephone number, including area code, of agent for service)**

**Copies to:** 

---

| | |
|:---|:---|
| **Mark Ballantyne**<br>**Michael E. Tenta<br>Cooley LLP<br>11951 Freedom Drive<br>Reston, VA 20190-5640<br>(703) 456-8000** | **Christopher W. Gerry<br>General Counsel and Secretary<br>Sensei Biotherapeutics, Inc.<br>1405 Research Blvd, Suite 125**<br> **Rockville, MD 20850<br>(240) 243-8000** |

---

_____________________________________

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

---

| | |
|:---|:---|
| &nbsp;&nbsp;Large accelerated filer ☐ | &nbsp;&nbsp;Accelerated filer ☐ |
| &nbsp;&nbsp;Non-accelerated filer ☒  | &nbsp;&nbsp;Smaller reporting company ☒ |
|  | &nbsp;&nbsp;Emerging growth company ☒ |

---

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ¨

------

EXPLANATORY NOTE

This Registration Statement on Form S-8 is being filed for the purpose of registering an additional (i) 307,641 shares of Common Stock of Sensei Biotherapeutics, Inc. to be issued pursuant to the 2021 Equity Incentive Plan ("2021 EIP") and (ii) 307,461 shares of Common Stock of Sensei Biotherapeutics, Inc. to be issued pursuant to the 2021 Employee Stock Purchase Plan (the "2021 ESPP"), pursuant to the provisions of the 2021 EIP

and 2021 ESPP providing for automatic increases in the number of shares of Common Stock reserved and available for issuance under the 2021 EIP and

2021 ESPP on January 1, 2023. In accordance with the instructional note to Part I of Form S-8 as promulgated by the Securities and Exchange

Commission, the information specified by Part I of the Form S-8 has been omitted from this Registration Statement.

PART II ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE

The contents of the earlier registration statement relating to (i) the 2018 Stock Incentive Plan, (ii) the 2021 EIP and (iii) the 2021 ESPP, previously filed with the Securities and Exchange Commission on February 10, 2021 (<u>File No. 333-252954</u>) are incorporated herein by reference and made a part

of this Registration Statement.

------

**ITEM 8. EXHIBITS Incorporated by Reference**

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
| **Exhibit**<br>**<u>Number</u>** | &nbsp;&nbsp; <br>**<u>Description</u>** | &nbsp;&nbsp;&nbsp;&nbsp;**Schedule**<br>**<u>Form</u>**  | &nbsp;&nbsp;&nbsp;**File** <br>**<u>Number</u>**  | &nbsp;&nbsp;&nbsp; <br>**<u>Exhibit</u>** | &nbsp;&nbsp;&nbsp; <br>**<u>Filing Date</u>**  |
| 4.1 | [<u>Amended and Restated Certificate of Incorporation.</u>](https://www.sec.gov/Archives/edgar/data/1829802/000119312521037280/d95909dex31.htm) | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8-K | &nbsp;&nbsp;&nbsp;&nbsp;001-39980 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.1 | &nbsp;&nbsp;&nbsp;&nbsp;02/11/2021 |
| 4.2 | [<u>Amended and Restated Bylaws.</u>](https://www.sec.gov/Archives/edgar/data/1829802/000119312521037280/d95909dex32.htm) | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8-K | &nbsp;&nbsp;&nbsp;&nbsp;001-39980 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.2 | &nbsp;&nbsp;&nbsp;&nbsp;02/11/2021 |
| 4.3 | [<u>Certificate of Designations of the Series A Junior Participating Cumulative Preferred Stock of the Registrant.</u>](https://www.sec.gov/Archives/edgar/data/1829802/000119312523063093/d470819dex31.htm) | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8-K | &nbsp;&nbsp;&nbsp;&nbsp;001-39980 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.1 | &nbsp;&nbsp;&nbsp;&nbsp;03/07/2023 |
| 4.4 | [<u>Stockholder Rights Agreement (which includes the form of Right Certificate as Exhibit B thereto).</u>](https://www.sec.gov/Archives/edgar/data/1829802/000119312523063093/d470819dex41.htm) | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8-K | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;001-39980 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;4.1 | &nbsp;&nbsp;&nbsp;&nbsp;03/07/2023 |
| 4.5 | [<u>Sensei Biotherapeutics, Inc. 2021 Equity Incentive Plan and forms of option agreements thereunder.</u>](https://www.sec.gov/Archives/edgar/data/1829802/000119312521023615/d43789dex102.htm) | &nbsp;&nbsp;&nbsp;&nbsp;S-1/A | &nbsp;&nbsp;&nbsp;&nbsp;333-252138 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.2 | &nbsp;&nbsp;&nbsp;&nbsp;02/01/2021 |
| 4.6 | [<u>Sensei Biotherapeutics, Inc. 2021 Employee Stock Purchase Plan.</u>](https://www.sec.gov/Archives/edgar/data/1829802/000119312521023615/d43789dex1010.htm) | &nbsp;&nbsp;&nbsp;&nbsp;S-1/A | &nbsp;&nbsp;&nbsp;&nbsp;333-252138 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;10.10 | &nbsp;&nbsp;&nbsp;&nbsp;02/01/2021 |
| 4.7 | [<u>Form of Restricted Stock Unit Grant Notice and Award Agreement under 2021 Equity Incentive Plan.</u>](https://www.sec.gov/Archives/edgar/data/1829802/000119312522146308/d298373dex45.htm) | &nbsp;&nbsp;&nbsp;&nbsp;S-8  | &nbsp;&nbsp;&nbsp;&nbsp;333-264827 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;4.5  | &nbsp;&nbsp;&nbsp;&nbsp;05/10/2022 |
| 5.1\* | [<u>Opinion of Cooley LLP.</u>](snse-ex5_1.htm) | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— |  |
| 23.1\* | [<u>Consent of Cooley LLP (included in Exhibit 5.1).</u>](snse-ex5_1.htm) | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— |  |
| 23.2\* | [<u>Consent of Deloitte & Touche LLP, independent registered public accounting firm.</u>](snse-ex23_2.htm) | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— |  |
| 24.1\* | Power of Attorney (included on the signature page of this Form S-8). | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— |  |
| 107\* | [<u>Filing Fee Table</u>](snse-exfiling_fees.htm) | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;— |  |

---

\* Filed herewith.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2. ------

**SIGNATURES**

Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Boston, Commonwealth of Massachusetts, on this 29th day of March, 2023.

---

| | | | |
|:---|:---|:---|:---|
|  |  | Sensei Biotherapeutics, Inc. | Sensei Biotherapeutics, Inc. |
| Date: | March 29, 2023 | By: | /s/ John Celebi |
|  |  |  | **John Celebi** |
|  |  |  | **President and Chief Executive Officer** |

---

**POWER OF ATTORNEY**

**KNOW ALL PERSONS BY THESE PRESENTS**, that each person whose signature appears below constitutes and appoints John Celebi and Erin Colgan, each of them, as his or her true and lawful attorneys-in-fact and agents, each with the full power of substitution, for him or her and in their name, place or stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement on Form S-8, and to file the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or any of them, or his, her or their substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, this Report has been signed below by the following persons on behalf of the Registrant in the capacities and on the dates indicated.

---

| | | |
|:---|:---|:---|
| **Name** | **Title** | **Date** |
| /s/ John Celebi | President, Chief Executive Officer and Director (Principal Executive Officer) | March 29, 2023 |
| **John Celebi** |  |  |
| /s/ Erin Colgan | Chief Financial Officer (Principal Financial and Accounting Officer) | March 29, 2023 |
| **Erin Colgan** |  |  |
| /s/ William Ringo | Chair | March 29, 2023 |
| **William Ringo** |  |  |
| /s/ Bob Holmen | Director | March 29, 2023 |
| **Bob Holmen** |  |  |
| /s/ James Peyer, Ph.D. | Director | March 29, 2023 |
| **James Peyer, Ph.D.** |  |  |
| /s/ Samuel Broder, M.D. | Director | March 29, 2023 |
| **Samuel Broder, M.D.** |  |  |
| /s/ Thomas Ricks | Director | March 29, 2023 |
| **Thomas Ricks** |  |  |
| /s/ Deneen Vojta, M.D. | Director | March 29, 2023 |
| **Deneen Vojta, M.D.** |  |  |
| /s/ Jessie English, Ph.D. | Director | March 29, 2023 |
| **Jessie English, Ph.D.** |  |  |
| /s/ Kristian Humer | Director | March 29, 2023 |
| **Kristian Humer** |  |  |

---

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3. ------

## Ex-5

Exhibit 5.1

![img268142887_0.jpg](img268142887_0.jpg)

Mark Ballantyne

T: +1 703 456 8084

mballantyne@cooley.com

March 29, 2023

Sensei Biotherapeutics, Inc. 451 D Street, Suite 710

Boston, MA 02210 Ladies and Gentlemen:

We have acted as counsel to Sensei Biotherapeutics, Inc., a Delaware corporation (the "**Company**"), in connection with the filing by the Company of a Registration Statement on Form S-8 (the "**Registration Statement**") with the Securities and Exchange Commission relating to the offering of up to 615,282 shares (the "**Shares**") of the Company's Common Stock, par value $0.0001 per share (the "**Common Stock**"), consisting of (i) 307,641 shares of the Company's Common Stock issuable pursuant to the Company's 2021 Equity Incentive Plan (the "**2021 EIP**"), (ii) 307,641 shares of the Company's Common Stock issuable pursuant to the Company's 2021 Employee Stock Purchase Plan (together with the 2021 EIP, the "**Plans**"), and (iii) the preferred stock purchase rights (the "**Rights**") associated with the Shares to be issued pursuant to that certain Stockholder Rights Agreement, dated March 7, 2023 (the "**Rights Agreement**"), between the Company and American Stock Transfer & Trust Company, LLC, as rights agent (the "**Rights Agent**").

In connection with this opinion, we have examined and relied upon (a) the Registration Statement and the related prospectuses, (b) the Company's certificate of incorporation and bylaws, each as currently in effect, (c) the Plans, (d) the Rights Agreement and (e) originals or copies certified to our satisfaction of such records, documents, certificates, memoranda and other instruments as in our judgment are necessary or appropriate to enable us to render the opinion expressed below. We have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to originals of all documents submitted to us as copies, the accuracy, completeness and authenticity of certificates of public officials and the due authorization, execution and delivery of all documents by all persons other than the Company where authorization, execution and delivery are prerequisites to the effectiveness thereof. As to certain factual matters, we have relied upon a certificate of an officer of the Company and have not independently verified such matters.

We have also assumed that the Rights Agreement has been duly authorized, executed and delivered by the Rights Agent and that the members of the Board of Directors of the Company (the "**Board**") have acted in a manner consistent with their fiduciary duties as required under applicable law in adopting the Rights Agreement. This opinion does not address the determination a court of competent jurisdiction may make regarding whether the Board may be required to redeem or terminate, or take other action with respect to, the Rights in the future based on the facts and circumstances then existing. Moreover, this opinion addresses corporate procedures in connection with the issuance of the Rights associated with the Shares, and not any particular provision of the Rights or the Rights Agreement. It should be understood that it is not settled whether the invalidity of any particular provision of a rights agreement or purchase rights issued thereunder would invalidate such rights in their entirety.

Our opinion is expressed only with respect to the General Corporation Law of the State of Delaware. We express no opinion to the extent that any other laws are applicable to the subject matter hereof and express no opinion and provide no assurance as to compliance with any federal or state securities law, rule or regulation.

Cooley LLP Reston Town Center 11951 Freedom Drive 14th Floor Reston, VA 20190-5656 t: +1 703 456 8000 f: +1 703 456 8100 cooley.com

------

![img268142887_1.jpg](img268142887_1.jpg)

March 29, 2023 Page Two

On the basis of the foregoing, and in reliance thereon, we are of the opinion that the Shares and the associated Rights, when sold and issued in accordance with the Plans, the Registration Statement and the related prospectuses, will be validly issued, and the Shares will be fully paid and nonassessable (except as to shares issued pursuant to deferred payment arrangements, which will be fully paid and nonassessable when such deferred payments are made in full).

We consent to the filing of this opinion as an exhibit to the Registration Statement. In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act of 1933, as amended, or the rules and regulations of the Commission thereunder.

Sincerely

Cooley LLP

By: <u>/s/ Mark Ballantyne</u> 

&nbsp;&nbsp;&nbsp;&nbsp;Mark Ballantyne

Cooley LLP Reston Town Center 11951 Freedom Drive 14th Floor Reston, VA 20190-5656 t: +1 703 456 8000 f: +1 703 456 8100 cooley.com

------

## Ex-23

Exhibit 23.2

**CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM**

We consent to the incorporation by reference in this Registration Statement on Form S-8 of our report dated March 29, 2023 relating to the financial statements of Sensei Biotherapeutics, Inc., appearing in the Annual Report on Form 10-K of Sensei Biotherapeutics, Inc. for the year ended December 31, 2022.

/s/ Deloitte & Touche LLP

Baltimore, Maryland

March 29, 2023

------

## Ex-Filing

Exhibit 107

Calculation of Filing Fee Table

<u>Form S-8</u> (Form Type)

<u>Sensei Biotherapeutics, Inc.</u>

(Exact Name of Registrant as Specified in its Charter)

Table 1: Newly Registered

---

| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
| &nbsp;&nbsp;&nbsp;Security Type | &nbsp;&nbsp;&nbsp;Security Class Title | &nbsp;&nbsp;&nbsp;Fee Calculation Rule | &nbsp;&nbsp;&nbsp;Amount<br>Registered(1) | &nbsp;&nbsp;&nbsp;Proposed<br>Maximum Offering Price Per Share | &nbsp;&nbsp;&nbsp;Maximum Aggregate Offering Price | &nbsp;&nbsp;&nbsp;<br>Fee Rate | &nbsp;&nbsp;&nbsp;Amount of Registration Fee |
| &nbsp;&nbsp;&nbsp;Security Type | &nbsp;&nbsp;&nbsp;Security Class Title | &nbsp;&nbsp;&nbsp;Fee Calculation Rule | &nbsp;&nbsp;&nbsp;Amount<br>Registered(1) | &nbsp;&nbsp;&nbsp;Proposed<br>Maximum Offering Price Per Share | &nbsp;&nbsp;&nbsp;Maximum Aggregate Offering Price | &nbsp;&nbsp;&nbsp;<br>Fee Rate | &nbsp;&nbsp;&nbsp;Amount of Registration Fee |
| &nbsp;&nbsp;Equity | &nbsp;&nbsp;Common Stock, par value<br>$0.0001 per share, Sensei<br>Biotherapeutics, Inc. 2021<br>Equity Incentive Plan, including related rights to purchase Series A Junior Participating Preferred Stock (2) | &nbsp;&nbsp;Other (3) | &nbsp;&nbsp;307461 (3) | &nbsp;&nbsp;$1.36 (5) | &nbsp;&nbsp;$418146.96  | &nbsp;&nbsp;$0.0001102  | &nbsp;&nbsp;$46.08 |
| &nbsp;&nbsp;Equity | &nbsp;&nbsp;Common Stock, par value<br>$0.0001 per share, Sensei<br>Biotherapeutics, Inc. 2021<br>Equity Incentive Plan, including related rights to purchase Series A Junior Participating Preferred Stock (2) | &nbsp;&nbsp;Other (3) | &nbsp;&nbsp;307461 (3) | &nbsp;&nbsp;$1.36 (5) | &nbsp;&nbsp;$418146.96  | &nbsp;&nbsp;$0.0001102  | &nbsp;&nbsp;$46.08 |
| &nbsp;&nbsp;Equity | &nbsp;&nbsp;Common Stock, par value<br>$0.0001 per share, Sensei<br>Biotherapeutics, Inc. 2021<br>Equity Incentive Plan, including related rights to purchase Series A Junior Participating Preferred Stock (2) | &nbsp;&nbsp;Other (3) | &nbsp;&nbsp;307461 (3) | &nbsp;&nbsp;$1.36 (5) | &nbsp;&nbsp;$418146.96  | &nbsp;&nbsp;$0.0001102  | &nbsp;&nbsp;$46.08 |
| &nbsp;&nbsp;Equity | &nbsp;&nbsp;Common Stock, par value<br>$0.0001 per share, Sensei<br>Biotherapeutics, Inc. 2021<br>Employee Share Purchase Plan, including related rights to purchase Series A Junior Participating Preferred Stock (2) | &nbsp;&nbsp;Other (4) | &nbsp;&nbsp;307461 (4) | &nbsp;&nbsp;$1.36 (5) | &nbsp;&nbsp;$418146.96 | &nbsp;&nbsp;$0.0001102  | &nbsp;&nbsp;$46.08 |
| &nbsp;&nbsp;Equity | &nbsp;&nbsp;Common Stock, par value<br>$0.0001 per share, Sensei<br>Biotherapeutics, Inc. 2021<br>Employee Share Purchase Plan, including related rights to purchase Series A Junior Participating Preferred Stock (2) | &nbsp;&nbsp;Other (4) | &nbsp;&nbsp;307461 (4) | &nbsp;&nbsp;$1.36 (5) | &nbsp;&nbsp;$418146.96 | &nbsp;&nbsp;$0.0001102  | &nbsp;&nbsp;$46.08 |
| &nbsp;&nbsp;Equity | &nbsp;&nbsp;Common Stock, par value<br>$0.0001 per share, Sensei<br>Biotherapeutics, Inc. 2021<br>Employee Share Purchase Plan, including related rights to purchase Series A Junior Participating Preferred Stock (2) | &nbsp;&nbsp;Other (4) | &nbsp;&nbsp;307461 (4) | &nbsp;&nbsp;$1.36 (5) | &nbsp;&nbsp;$418146.96 | &nbsp;&nbsp;$0.0001102  | &nbsp;&nbsp;$46.08 |
| &nbsp;&nbsp;Total Offering Amount | &nbsp;&nbsp;Total Offering Amount | &nbsp;&nbsp;Total Offering Amount | &nbsp;&nbsp;Total Offering Amount |  | &nbsp;&nbsp;$836293.92 |  | &nbsp;&nbsp;— |
| &nbsp;&nbsp;Total Fees Previously Paid | &nbsp;&nbsp;Total Fees Previously Paid | &nbsp;&nbsp;Total Fees Previously Paid | &nbsp;&nbsp;Total Fees Previously Paid |  |  |  | &nbsp;&nbsp;— |
| &nbsp;&nbsp;Total Fee Offsets | &nbsp;&nbsp;Total Fee Offsets | &nbsp;&nbsp;Total Fee Offsets | &nbsp;&nbsp;Total Fee Offsets |  |  |  | &nbsp;&nbsp;— |
| &nbsp;&nbsp;Net Fee Due | &nbsp;&nbsp;Net Fee Due | &nbsp;&nbsp;Net Fee Due | &nbsp;&nbsp;Net Fee Due |  |  |  | &nbsp;&nbsp;$92.16 |

---

(1) Pursuant to Rule 416(a) promulgated under the Securities Act of 1933, as amended (the "Securities Act"), this Registration Statement shall also cover any additional shares of common stock, par value $0.0001 per share ("Common Stock") of Sensei Biotherapeutics, Inc. (the "Registrant") that become issuable under the 2021 Equity Incentive Plan (the "2021 EIP") or 2021 Employee Stock Purchase Plan (the "2021 ESPP") set forth herein by reason of any stock dividend, stock split, recapitalization, or other similar transaction effected that results in an increase to the number of outstanding shares of Registrant's Common Stock, as applicable.

(2) Each share of the Registrant's Common Stock being registered hereunder, if issued prior to the termination by the Registrant of its Stockholder Rights Agreement (the "Rights Agreement"), dated March 7, 2023, between the Registrant and the rights agent named therein, includes Series A Junior Participating Cumulative Preferred Stock purchase rights (the "Rights"). Prior to the occurrence of certain events, the Rights will not be exercisable or evidenced separately from the Registrant's Common Stock and have no value except as reflected in the market price of the shares to which they are attached.

&nbsp;&nbsp;&nbsp;&nbsp;(3) Represents shares of Common Stock that were added to the shares authorized for issuance under the 2021 EIP on January 1, 2023 pursuant to an

"evergreen" provision contained in the 2021 EIP.

(4) Represents shares of Common Stock that were added to the shares authorized for future issuance under the 2021 ESPP on January 1, 2023 pursuant to an "evergreen" provision contained in the 2021 ESPP.

(5) Estimated in accordance with Rule 457(c) and Rule 457(h) promulgated under the Securities Act solely for the purpose of calculating the registration fee. The offering price per share and the aggregate offering price are based upon a per share price of $1.36, which is the average of the high and low prices per share of the Registrant's Common Stock on March 24, 2023, as reported on The Nasdaq Global Market.

------