[144] Centessa Pharmaceuticals plc SEC Filing

Rhea-AI Filing Summary

Centessa Pharmaceuticals (CNTA) Form 144 notice reports a proposed sale of 8,172 common shares through UBS Financial Services on Nasdaq, with an aggregate market value of $180,274.32 and an approximate sale date of 09/16/2025. The filer acquired most of these shares as founders' shares on 01/02/2020 (7,500 shares) and received 672 RSU shares on 08/01/2024. The filing also discloses three sales by the same person in the past three months totaling 30,322 shares for gross proceeds of $476,750.72. The notice includes the standard attestation that the seller is not aware of undisclosed material adverse information.

Positive

• Full Rule 144 disclosure filed with broker, sale date, share counts, and acquisition details
• Acquisitions documented (founders' shares and RSU vest) clarifying origin of securities

Negative

• Significant insider selling in the past three months (30,322 shares) plus the proposed 8,172-share sale
• Concentrated disposition timing may increase free float and could be perceived negatively by investors

Insights

Securities Analyst

TL;DR: Insider sale activity is notable but the filing is routine disclosure under Rule 144.

The Form 144 shows a proposed disposal of 8,172 common shares valued at $180,274.32 and recent completed sales totaling 30,322 shares for $476,750.72.

From a market impact perspective, these are insider-originated sales rather than company actions; they can increase available float and may be seen as modestly negative by investors seeking insider buying signals. The disclosure is complete for Rule 144 purposes, naming broker, dates, acquisition types (founders shares and RSU vest) and prior sales amounts, which supports transparency.

Corporate Governance Expert

TL;DR: Repeated insider sales within months raise governance and signaling concerns despite regulatory compliance.

Multiple sales by the same individual—15,000 on 06/24/2025, 8,322 on 07/29/2025, 7,000 on 09/09/2025—and a further proposed sale suggest a pattern of selling by an insider. While each sale is disclosed and appears executed through an institutional broker, the concentration of dispositions over a short period is material to investor perception of insider confidence.

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK
Filer CCC
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer

SEC File Number

Address of Issuer

Phone

Name of Person for Whose Account the Securities are To Be Sold

See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.

Relationship to Issuer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	UBS Financial Services, Inc Eleven Madison Avenue 4th Floor New York NY 10010	8172	180274.32	134073436	09/16/2025	Nasdaq

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	01/02/2020	Founders Shares	Issuer			7500	01/02/2020	NA
Common	08/01/2024	RSU Vest	Issuer			672	08/01/2024	NA

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Mario Alberto Accardi 3RD FLOOR 1 ASHLEY ROAD ALTRINCHAM, CHESHIRE X0 WA14 2DT	Common	06/24/2025	15000	210000.00
Mario Alberto Accardi 3RD FLOOR 1 ASHLEY ROAD ALTRINCHAM, CHESHIRE X0 WA14 2DT	Common	07/29/2025	8322	126750.72
Mario Alberto Accardi 3RD FLOOR, 1 ASHLEY ROAD ALTRINCHAM, CHESHIRE X0 WA14 2DT	Common	09/09/2025	7000	140000.00

144: Remarks and Signature

Remarks

Date of Notice

Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1

ATTENTION:

The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.

Signature

ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)

FAQ

What is Centessa Pharmaceuticals (CNTA) proposing to sell under this Form 144?

The filer proposes to sell 8,172 common shares through UBS Financial Services on Nasdaq with an aggregate market value of $180,274.32 and an approximate sale date of 09/16/2025.

How were the proposed shares acquired by the filer?

The filing shows 7,500 shares acquired as founders' shares on 01/02/2020 and 672 shares from an RSU vest on 08/01/2024.

Has the filer sold other CNTA shares recently?

Yes. The filer sold 15,000 shares on 06/24/2025, 8,322 shares on 07/29/2025, and 7,000 shares on 09/09/2025, totaling 30,322 shares for gross proceeds of $476,750.72.

Through which broker will the proposed sale be executed?

The proposed sale is to be executed through UBS Financial Services, Inc, located at Eleven Madison Avenue, New York, NY.

Does the filing state whether the filer knows any undisclosed material information?

Yes. By signing the notice the filer represents they do not know any material adverse information regarding the issuer that has not been publicly disclosed.