# EDGAR Filing Document

**Accession Number:** 0001587114
**File Stem:** 0000935836-25-000476
**Filing Date:** 2025-7
**Character Count:** 9105
**Document Hash:** fc847509e6e56e2a44a864f3f0f2bf74
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000935836-25-000476.hdr.sgml**: 20250730

**ACCESSION NUMBER**: 0000935836-25-000476

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250728

**FILED AS OF DATE**: 20250730

**DATE AS OF CHANGE**: 20250730

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** EcoR1 Capital, LLC
- **CENTRAL INDEX KEY:** 0001587114

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

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-37368
- **FILM NUMBER:** 251168504

**BUSINESS ADDRESS:**
- **STREET 1:** 357 TEHAMA STREET #3
- **CITY:** SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94103
- **BUSINESS PHONE:** 415-448-6534

**MAIL ADDRESS:**
- **STREET 1:** 357 TEHAMA STREET #3
- **CITY:** SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94103
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Adaptimmune Therapeutics PLC
- **CENTRAL INDEX KEY:** 0001621227
- **STANDARD INDUSTRIAL CLASSIFICATION:** BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** X0
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** 60 JUBILEE AVENUE
- **STREET 2:** MILTON PARK
- **CITY:** ABINGDON, OXFORDSHIRE
- **PROVINCE COUNTRY:** X0
- **BUSINESS PHONE:** 44 1235 430000

**MAIL ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** 60 JUBILEE AVENUE
- **STREET 2:** MILTON PARK
- **CITY:** ABINGDON, OXFORDSHIRE
- **PROVINCE COUNTRY:** X0

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Adaptimmune Ltd
- **DATE OF NAME CHANGE:** 20141001

### 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>EcoR1 Capital, LLC<br><sub>(Last) (First) (Middle)</sub><br>357 TEHAMA STREET #3<br><sub>(Street)</sub><br>SAN FRANCISCO, CA 94103<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-07-28 | **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>Adaptimmune Therapeutics PLC [ ADAP ] | **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 |
| Ordinary Shares<sup>(1)</sup> | 2025-07-28 |  | S |  | 33931740<sup>(3)</sup> | D | 0.1125<sup>(4)</sup> | 130492680<sup>(5)</sup> | I | See Note<sup>(2)</sup> |
| Ordinary Shares<sup>(1)</sup> | 2025-07-29 |  | S |  | 2687460<sup>(6)</sup> | D | 0.1012<sup>(7)</sup> | 127805220<sup>(8)</sup> | I | See Note<sup>(2)</sup> |
| Ordinary Shares<sup>(1)</sup> | 2025-07-30 |  | S |  | 27433338<sup>(9)</sup> | D | 0.1021<sup>(7)</sup> | 100371882<sup>(10)</sup> | I | See Note<sup>(2)</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) These Ordinary Shares are held through American Depositary Shares ("ADS") of the Issuer. Each ADS represents 6 Ordinary Shares.

(2) The reporting persons are EcoR1 Capital, LLC ("Ecor1"), Oleg Nodelman and EcoR1 Capital Fund Qualified, L.P. ("Qualified Fund"). EcoR1 is the general partner and investment adviser of private funds, including Qualified Fund (the "Fund"). Mr. Nodelman is the manager and controlling owner of EcoR1. EcoR1 is filing this Form 4 for itself, Mr. Nodelman and Qualified Fund. The filers are filing this Form 4 jointly, but not as a group, and each expressly disclaims membership in a group within the meaning of Rule 13d-5(b) under the Securities Exchange Act of 1934. The Funds hold these securities directly for the benefit of their investors. EcoR1 may be deemed to indirectly beneficially own them as the investment adviser to the Funds. Mr. Nodelman may be deemed to indirectly beneficially own them as the control person of EcoR1. The filers disclaim beneficial ownership of the securities except to the extent of their respective pecuniary interests therein.

(3) The reporting persons sold 5,655,290 ADSs representing 33,931,740 Ordinary Shares. Qualified Fund sold 5,281,476 of those ADSs, representing 31,688,856 Ordinary Shares.

(4) The price reported in Column 4 is the price per ADS sold by the reporting persons. This price is a weighted average price. These ADSs were sold in multiple transactions at prices ranging from $0.1086 to $0.1184, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission upon request, full information regarding the number of ADSs sold at each separate price within the ranges set forth in this footnote.

(5) After this transaction, the reporting persons beneficially owned 21,748,780 ADSs, including 20,569,634 ADS held by Qualified Fund representing 123,417,804 Ordinary Shares.

(6) The reporting persons sold 447,910 ADSs representing 2,687,460 Ordinary Shares. Qualified Fund sold 418,303 of those ADSs, representing 2,509,818 Ordinary Shares.

(7) The price reported in Column 4 is the price per ADS sold by the reporting persons.

(8) After this transaction, the reporting persons beneficially owned 21,300,870 ADSs, including 20,151,331 ADSs held by Qualified Fund representing 120,907,986 Ordinary Shares.

(9) The reporting persons sold 4,572,223 ADSs representing 27,433,338 Ordinary Shares. Qualified Fund sold 4,270,000 of those ADSs, representing 25,620,000 Ordinary Shares.

(10) After this transaction, the reporting persons beneficially owned 16,728,647 ADSs, including 15,881,331 ADSs held by Qualified Fund representing 95,287,986 Ordinary Shares.

**Signature:** /s/ Oleg Nodelman  
**Date:** 2025-07-30

### 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.**