Centessa Pharmaceuticals Plc SEC Filings

Tia L. Bush, Chief Technology & Quality Officer of Centessa Pharmaceuticals plc (CNTA), reported insider transactions on 09/24/2025. The filing shows the exercise of a stock option to acquire 35,000 ordinary shares at an exercise price of $9.42 and a contemporaneous sale of 35,000 ordinary shares at $24.00 executed under a Rule 10b5-1 trading plan adopted on 09/14/2024. After the non-derivative transactions the filing lists 156,503 shares beneficially owned following the acquisition and 121,503 shares following the sale. The related option covers 35,000 underlying ordinary shares, is exercisable in accordance with the stated vesting schedule, has an exercise price of $9.42 and an expiration date of 05/07/2031. The Form 4 is signed by an attorney-in-fact, Raphael Deferiere, dated 09/24/2025.

Form 144 filed for Centessa Pharmaceuticals plc (CNTA) shows a proposed sale of 35,000 common shares through UBS Financial Services on NASDAQ, with an aggregate market value of $840,000 and an approximate sale date of 09/24/2025. The shares were acquired and paid for on 09/24/2025 by exercise of stock options from the issuer. The filer reported prior open-market sales in the past three months: 24,792 shares on 09/09/2025 for $495,840 and 25,000 shares on 09/10/2025 for $550,000, totaling 49,792 shares and $1,045,840 in gross proceeds. Outstanding shares are listed as 134,073,436, making the proposed 35,000-share sale about 0.026% of outstanding common stock. The filing includes the standard Rule 144 representation regarding material nonpublic information.

Mario Alberto Accardi, President, Orexin Program at Centessa Pharmaceuticals plc (CNTA), reported two sales of Ordinary Shares on 09/16/2025 executed under a Rule 10b5-1 trading plan adopted February 14, 2025. The Form 4 shows a disposition of 7,430 shares at a weighted-average price of $21.3333, leaving 198,136 shares beneficially owned, and a disposition of 742 shares at a weighted-average price of $22.0213, leaving 197,394 shares beneficially owned. The filing notes Ordinary Shares may be represented by American Depositary Shares on a one-for-one basis and provides price ranges for the multiple transactions comprising each weighted average.

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.

Centessa Pharmaceuticals plc (CNTA) Form 144 notice: This filing reports a proposed sale of 6,000 common shares to be executed through UBS Financial Services on Nasdaq with an aggregate market value of $130,860 and an acquisition date of 09/15/2025 by exercise of stock options paid in cash. The filer previously sold multiple blocks of common shares during the past three months: 12,000 on 06/24/2025 for $168,218.40; 6,000 on 07/15/2025 for $89,566.80; 6,000 on 08/15/2025 for $103,380.00; and two larger sales on 09/09/2025 and 09/10/2025 of 20,000 shares each for $400,102.00 and $440,000.00 respectively. The notice includes the required representation that the seller is not aware of undisclosed material adverse information.

Centessa Pharmaceuticals (CNTA) insider activity: Chief Technology & Quality Officer Tia L. Bush reported option exercises and matched sales on September 9-10, 2025. On 09/09/2025 she acquired 24,792 ordinary shares at $8.01 per share and on the same day sold 24,792 shares at $20 per share pursuant to a Rule 10b5-1 trading plan adopted September 14, 2024. On 09/10/2025 she acquired 25,000 shares at $9.42 and sold 25,000 shares at $22. Following the reported transactions, Ms. Bush beneficially owned 121,503 ordinary shares directly. The filing also discloses outstanding options: 24,792 shares underlying an option exercisable from 02/01/2034 (strike $8.01) and 25,000 shares underlying an option exercisable from 05/07/2031 (strike $9.42).

Centessa Pharmaceuticals plc director and General Counsel Hussain Iqbal J reported multiple transactions in ordinary shares and share options on 09/09/2025 and 09/10/2025. The Form 4 shows purchases of 20,000 ordinary shares on each date at $5.84 per share and contemporaneous sales of 20,000 shares on each date: a weighted average sale price of $20.0051 on 09/09/2025 (sales ranged $20.00–$20.03) and sales at $22.00 on 09/10/2025. After the reported transactions the reporter’s directly held ordinary shares are shown as 105,386. The filing discloses 20,000 share options exercisable at $5.84 (vesting schedule described) and indicates 5,500 shares held indirectly by the reporter’s spouse. The sales on 09/09/2025 were effected pursuant to a Rule 10b5-1 trading plan adopted on September 14, 2024.

Mario Alberto Accardi, an officer and director of Centessa Pharmaceuticals plc (CNTA), reported insider transactions on 09/09/2025. He exercised 5,000 share options at an $8.01 exercise price and received 5,000 ordinary shares. He also sold 7,000 ordinary shares at $20.00 under a Rule 10b5-1 trading plan adopted February 14, 2025. Following these transactions, Accardi beneficially owns 205,566 ordinary shares. The option exercised remains partially unvested per the disclosed vesting schedule (1/48th monthly with first installment March 1, 2024). The Form 4 is signed by an attorney-in-fact on Accardi's behalf.

Form 144 notice for Centessa Pharmaceuticals plc (CNTA) reports a proposed sale of 25,000 common shares through UBS Financial Services on 09/10/2025 on NASDAQ with an aggregate market value of $550,000.00. The shares were acquired and paid for on 09/10/2025 by exercise of a stock option and payment in cash. The filing lists 134,073,436 shares outstanding. The filing also discloses a sale the prior day: 24,792 shares sold on 09/09/2025 for gross proceeds of $495,840.00 by Tia Bush. The filer certifies no undisclosed material adverse information and includes standard Rule 10b5-1/trading-plan language.