# EDGAR Filing Document

**Accession Number:** 0001783647
**File Stem:** 0001104659-26-062608
**Filing Date:** 2026-5
**Character Count:** 16914
**Document Hash:** 10ffc6d4ca4344268ced30733975a5da
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-26-062608.hdr.sgml**: 20260515

**ACCESSION NUMBER**: 0001104659-26-062608

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260402

**FILED AS OF DATE**: 20260515

**DATE AS OF CHANGE**: 20260515

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** ENGLANDER ISRAEL A
- **CENTRAL INDEX KEY:** 0001017456

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39980
- **FILM NUMBER:** 26988159

**MAIL ADDRESS:**
- **STREET 1:** C/O MILLENNIUM MANAGEMENT LLC
- **STREET 2:** 399 PARK AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10022
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** MILLENNIUM MANAGEMENT LLC
- **CENTRAL INDEX KEY:** 0001273087

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39980
- **FILM NUMBER:** 26988162

**BUSINESS ADDRESS:**
- **STREET 1:** 399 PARK AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10022
- **BUSINESS PHONE:** (212) 841-4100

**MAIL ADDRESS:**
- **STREET 1:** 399 PARK AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10022

**FORMER NAME:**
- **FORMER CONFORMED NAME:** MILLENNIUM MANAGEMENT, L.L.C.
- **DATE OF NAME CHANGE:** 20050310

**FORMER NAME:**
- **FORMER CONFORMED NAME:** MILLENNIUM MANAGEMENT LLC
- **DATE OF NAME CHANGE:** 20031212
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** MILLENNIUM GROUP MANAGEMENT LLC
- **CENTRAL INDEX KEY:** 0001446830

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39980
- **FILM NUMBER:** 26988160

**BUSINESS ADDRESS:**
- **STREET 1:** C/O MILLENNIUM MANAGEMENT LLC
- **STREET 2:** 399 PARK AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10022
- **BUSINESS PHONE:** (212) 841-4100

**MAIL ADDRESS:**
- **STREET 1:** C/O MILLENNIUM MANAGEMENT LLC
- **STREET 2:** 399 PARK AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10022

**FORMER NAME:**
- **FORMER CONFORMED NAME:** MILLENNIUM INTERNATIONAL MANAGEMENT GP LLC
- **DATE OF NAME CHANGE:** 20081002
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** ICS OPPORTUNITIES II LLC
- **CENTRAL INDEX KEY:** 0001783647

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** E9
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39980
- **FILM NUMBER:** 26988161

**BUSINESS ADDRESS:**
- **STREET 1:** MILLENNIUM INTERNATIONAL MANAGEMENT LP
- **STREET 2:** 399 PARK AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10022
- **BUSINESS PHONE:** (212) 841-4100

**MAIL ADDRESS:**
- **STREET 1:** MILLENNIUM INTERNATIONAL MANAGEMENT LP
- **STREET 2:** 399 PARK AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10022
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Sensei Biotherapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001829802
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 1405 RESEARCH BLVD, SUITE 125
- **CITY:** ROCKVILLE
- **STATE:** MD
- **ZIP:** 20850
- **BUSINESS PHONE:** (240) 243-8000

**MAIL ADDRESS:**
- **STREET 1:** 1405 RESEARCH BLVD, SUITE 125
- **CITY:** ROCKVILLE
- **STATE:** MD
- **ZIP:** 20850

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

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[x] 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>MILLENNIUM MANAGEMENT LLC<br><sub>(Last) (First) (Middle)</sub><br>399 PARK AVENUE<br><sub>(Street)</sub><br>NEW YORK, NY 10022<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-04-02 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sensei Biotherapeutics, Inc. [ SNSE ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>ICS OPPORTUNITIES II LLC<br><sub>(Last) (First) (Middle)</sub><br>C/O MILLENNIUM MANAGEMENT LLC<br>399 PARK AVENUE<br><sub>(Street)</sub><br>NEW YORK, NY 10022<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-04-02 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sensei Biotherapeutics, Inc. [ SNSE ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>MILLENNIUM GROUP MANAGEMENT LLC<br><sub>(Last) (First) (Middle)</sub><br>399 PARK AVENUE<br><sub>(Street)</sub><br>NEW YORK, NY 10022<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-04-02 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sensei Biotherapeutics, Inc. [ SNSE ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>ENGLANDER ISRAEL A<br><sub>(Last) (First) (Middle)</sub><br>C/O MILLENNIUM MANAGEMENT LLC<br>399 PARK AVENUE<br><sub>(Street)</sub><br>NEW YORK, NY 10022<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-04-02 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sensei Biotherapeutics, Inc. [ SNSE ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] 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 | 2026-04-02 |  | P |  | 26 | A | 33.4704<sup>(1)</sup> | 144974<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-02 |  | P |  | 1276 | A | 34.7524<sup>(4)</sup> | 144974<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-02 |  | P |  | 701 | A | 35.5472<sup>(5)</sup> | 144974<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-02 |  | S |  | 3099 | D | 30.8638<sup>(6)</sup> | 144974<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-02 |  | S |  | 1265 | D | 31.7510<sup>(7)</sup> | 144974<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-02 |  | S |  | 1794 | D | 32.6041<sup>(8)</sup> | 144974<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-02 |  | S |  | 374 | D | 33.3470<sup>(9)</sup> | 144974<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-02 |  | S |  | 1134 | D | 34.8007<sup>(10)</sup> | 144974<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-06 |  | P |  | 1104 | A | 31.0200<sup>(11)</sup> | 141029<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-06 |  | S |  | 1214 | D | 31.0227<sup>(12)</sup> | 141029<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-06 |  | S |  | 45 | D | 31.9628<sup>(13)</sup> | 141029<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-07 |  | P |  | 1108 | A | 33.3800<sup>(14)</sup> | 133986<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-07 |  | S |  | 2115 | D | 28.9417<sup>(15)</sup> | 133986<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-07 |  | S |  | 205 | D | 29.7146<sup>(16)</sup> | 133986<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-07 |  | S |  | 4423 | D | 31.3843<sup>(17)</sup> | 133986<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-07 |  | S |  | 300 | D | 32.2467<sup>(18)</sup> | 133986<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |
| Common Stock | 2026-04-07 |  | S |  | 1108 | D | 33.3800<sup>(19)</sup> | 133986<sup>(2)</sup> | I | See Footnote<sup>(3)</sup> |

---

## 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 |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

---

### Footnotes:

(1) Represents volume-weighted average price ("VWAP") of purchases of 26 shares of common stock ("Common Stock"), par value $0.0001 per share, of Sensei Biotherapeutics, Inc. (the "Company") on April 2, 2026 at prices ranging from $32.90 to $33.62. Upon request by the Commission staff, the Company, or a security holder of the Company, the reporting persons will provide full information regarding the number of shares purchased or sold by the reporting person at each separate price within each range represented by a VWAP disclosed herein.

(2) In each case, the number of shares of the Company's Common Stock disclosed in column 5 is the number of shares of the Company's Common Stock beneficially owned by Millennium Management LLC at the conclusion of the transactions on the date disclosed in the corresponding entry in column 2.

(3) The transactions in the Company's Common Stock reported herein were made by ICS Opportunities II LLC or other trading entities, in each case subject to voting control and investment discretion by Millennium Management LLC, Millennium Group Management LLC (the managing member of Millennium Management LLC) and Israel A. Englander (the sole voting trustee of the managing member of Millennium Group Management LLC). Each reporting person disclaims beneficial ownership of the shares of the Company's Common Stock disclosed herein except to the extent of such reporting person's pecuniary interest therein, if any.

(4) Represents VWAP of purchases of 1,276 shares of the Company's Common Stock on April 2, 2026 at prices ranging from $33.97 to $34.90.

(5) Represents VWAP of purchases of 701 shares of the Company's Common Stock on April 2, 2026 at prices ranging from $35.4481 to $35.91.

(6) Represents VWAP of sales of 3,099 shares of the Company's Common Stock on April 2, 2026 at prices ranging from $30.1332 to $31.1212.

(7) Represents VWAP of sales of 1,265 shares of the Company's Common Stock on April 2, 2026 at prices ranging from $31.21 to $32.15.

(8) Represents VWAP of sales of 1,794 shares of the Company's Common Stock on April 2, 2026 at prices ranging from $32.22 to $33.1251.

(9) Represents VWAP of sales of 374 shares of the Company's Common Stock on April 2, 2026 at prices ranging from $33.23 to $33.45.

(10) Represents VWAP of sales of 1,134 shares of the Company's Common Stock on April 2, 2026 at prices ranging from $34.40 to $35.25.

(11) Represents purchases of 1,104 shares of the Company's Common Stock on April 6, 2026 at $31.02 per share.

(12) Represents VWAP of sales of 1,214 shares of the Company's Common Stock on April 6, 2026 at prices ranging from $30.64 to $31.345.

(13) Represents VWAP of sales of 45 shares of the Company's Common Stock on April 6, 2026 at prices ranging from $31.80 to $32.17.

(14) Represents VWAP of purchases of 1,108 shares of the Company's Common Stock on April 7, 2026 at $33.38 per share.

(15) Represents VWAP of sales of 2,115 shares of the Company's Common Stock on April 7, 2026 at prices ranging from $28.5071 to $29.3167.

(16) Represents VWAP of sales of 205 shares of the Company's Common Stock on April 7, 2026 at prices ranging from $29.695 to $30.50.

(17) Represents VWAP of sales of 4,423 shares of the Company's Common Stock on April 7, 2026 at prices ranging from $30.9852 to $31.813.

(18) Represents VWAP of sales of 300 shares of the Company's Common Stock on April 7, 2026 at prices ranging from $32.0625 to $32.615.

(19) Represents sales of 1,108 shares of the Company's Common Stock on April 7, 2026 at $33.38 per share.

**Remarks:**
Assuming, without conceding, the application of Section 16(b) of the Securities Exchange Act of 1934, the reporting persons have disgorged to the Company all amounts that could be deemed profit realized by them from the transactions in the Company's Common Stock reported on this Form 4 and the other two statements on Form 4 filed by Millennium Management LLC on the same date.

**Signature:** MILLENNIUM MANAGEMENT LLC: By: /s/ Gil Raviv, Global General Counsel  
**Date:** 2026-05-14

**Signature:** ICS OPPORTUNITIES II LLC, By: Millennium Management LLC, its Investment Manager: By: /s/ Gil Raviv, Global General Counsel  
**Date:** 2026-05-14

**Signature:** MILLENNIUM GROUP MANAGEMENT LLC: By: /s/ Gil Raviv, Global General Counsel  
**Date:** 2026-05-14

**Signature:** /s/ Israel A. Englander  
**Date:** 2026-05-14

### 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.**