[Form 4] Adaptimmune Therapeutics plc American Insider Trading Activity

Rhea-AI Filing Summary

Adaptimmune insider sales by a director reduced his indirect holdings to zero. Ali Behbahani, a director and manager of entities holding shares, reported two dispositions of Adaptimmune ordinary shares represented by ADSs. On 08/15/2025 he reported sale of 4,828,206 ordinary shares at a weighted average price of $0.011 per share, leaving 14,671,794 shares indirectly owned. On 08/18/2025 he reported sale of 14,671,794 ordinary shares at a weighted average price of $0.012 per share, resulting in zero indirect beneficial ownership. The filings state these ordinary shares were held as ADSs by NEA 16 and explain price ranges and ownership through NEA entities.

Positive

• Full disclosure of transaction details including weighted average prices and price ranges
• Clarification of ownership structure showing sales occurred through NEA entities and ADS mechanics
• Undertaking to provide transaction-level price details to the issuer or SEC upon request

Negative

• Complete indirect divestiture by a director-associated manager, reducing reported indirect holdings to zero
• Large insider sales executed over a short period (08/15/2025 and 08/18/2025) representing significant share volume

Insights

Securities Analyst

TL;DR: A director-associated investor fully divested its indirect stake via two ADS-based sales within three days.

The Form 4 shows staged dispositions totaling 19,499,? ? (sum of 4,828,206 and 14,671,794) ordinary shares represented by ADSs managed through NEA entities, executed on 08/15/2025 and 08/18/2025 at weighted average per-share prices of $0.011 and $0.012 respectively. The reporting person disclaims direct pecuniary interest beyond the NEA structure. For investors, the filing is a clear disclosure of insider-related liquidation and complete indirect exit from the reported position.

Corporate Governance Expert

TL;DR: Filing documents compliant, timely insider sales and clarifies complex indirect ownership through fund GP structure.

The report provides transparent mechanics: ADSs representing six ordinary shares each, weighted average price derivations, and the reporting person's role as manager of NEA GP entities. The disclosure includes undertaking to provide detailed per-transaction price breakdowns on request, which supports regulatory compliance and record completeness. The filings leave no remaining indirect holdings reported.

SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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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^*

Behbahani Ali

(Last) (First) (Middle)

2855 SAND HILL ROAD

(Street)

MENLO PARK CA 94025

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Adaptimmune Therapeutics PLC [ ADAP ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
08/15/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Ordinary Shares with a nominal value of 0.001 GBP per share(1)	08/15/2025		S		4,828,206	D	$0.011(2)	14,671,794	I	See Note 3(3)
Ordinary Shares with a nominal value of 0.001 GBP per share(1)	08/18/2025		S		14,671,794	D	$0.012(4)	0	I	See Note 3(3)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. The Ordinary Shares whose sale is reported in this row are represented by American Depositary Shares ("ADSs") and are held of record by New Enterprise Associates 16, L.P. ("NEA 16"). NEA 16 holds these Ordinary Shares in the form of ADSs. Each ADS represents six Ordinary Shares of Adaptimmune Therapeutics plc (the "Issuer").

2. The prices reported in Column 4 are per Ordinary Share and were derived from the price per ADS divided by six. The reported price of $0.011 is a weighted average price. These ADSs were sold in multiple transactions at prices ranging from $0.0099 to $0.0118 per Ordinary Share, 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 (the "SEC"), upon request, full information regarding the number of ADSs sold at each separate price within the range set forth in this footnote.

3. The Reporting Person is a manager of NEA 16 GP, LLC ("NEA 16 GP"), which is the sole general partner of NEA Partners 16, L.P. ("NEA Partners 16"). NEA Partners 16 is the sole general partner of NEA 16, which is the direct beneficial owner of the securities. The Reporting Person disclaims beneficial ownership within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise of such portion of the securities held by NEA 16 in which the Reporting Person has no pecuniary interest.

4. The prices reported in Column 4 are per Ordinary Share and were derived from the price per ADS divided by six. The reported price of $0.012 is a weighted average price. These ADSs were sold in multiple transactions at prices ranging from $0.0114 to $0.0130 per Ordinary Share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of ADSs sold at each separate price within the range set forth in this footnote.

	/s/ Zachary Bambach, attorney-in-fact	08/19/2025
	** Signature of Reporting Person	Date
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.

FAQ

What transactions were reported on the ADAP Form 4?

The Form 4 reports two dispositions: sale of 4,828,206 ordinary shares on 08/15/2025 at a weighted average price of $0.011 per share and sale of 14,671,794 ordinary shares on 08/18/2025 at a weighted average price of $0.012 per share.

Who is the reporting person on this Form 4 for ADAP?

The reporting person is Ali Behbahani, identified as a director and a manager of NEA-related entities that held the ADSs representing the ordinary shares.

Did the reporting person retain any ADAP shares after these transactions?

No. After the reported 08/18/2025 sale of 14,671,794 ordinary shares, the filing shows 0 ordinary shares beneficially owned following the transactions.

How were the ordinary share prices derived in the filing?

Prices are reported per ordinary share and were derived by dividing the ADS price by six; the filing discloses the per-share price ranges used to calculate the weighted averages.

Through what vehicle were the ordinary shares held?

The ordinary shares were held of record by New Enterprise Associates 16, L.P. (NEA 16) in the form of ADSs, each ADS representing six ordinary shares.