4basebio Plc - Holding(s) in Company

TR-1: Standard form for notification of major holdings

NOTIFICATION OF MAJOR HOLDINGS (to be sent to the relevant issuer and to the FCA in Microsoft Word format if possible) i1a. Identity of the issuer or the underlying issuer of existing shares to which voting rights are attached ii: 4basebio PLC1b. Please indicate if the issuer is a non-UK issuer  (please mark with an “X” if appropriate)Non-UK issuer2. Reason for the notification (please mark the appropriate box or boxes with an “X”)An acquisition or disposal of voting rightsXAn acquisition or disposal of financial instrumentsAn event changing the breakdown of voting rightsOther (please specify) iii: acting in concert under DTR 5.2.1(a) X3. Details of person subject to the notification obligation iv NameM&G plc (as indirect parent shareholder under DTR 5.1.2 and 5.2.1(e) and indirect holder of voting rights under DTR 5.2.1(a))City and country of registered office (if applicable)London, United Kingdom4. Full name of shareholder(s) (if different from 3.) vNameThe Prudential Assurance Company Limited (as direct shareholder) and Fort Aggregator, LP (as the other party to the agreement under DTR5.2.1(a)) City and country of registered office (if applicable)

Prudential Assurance Company Limited: London, United Kingdom

Fort Aggregator, LP: Wilmington, Delaware, United States

5. Date on which the threshold was crossed or reached vi:13 November 20246. Date on which issuer notified (DD/MM/YYYY):14 November 20247. Total positions of person(s) subject to the notification obligation% of voting rights attached to shares (total of 8. A)% of voting rights through financial instruments(total of 8.B 1 + 8.B 2)Total of both in % (8.A + 8.B)Total number of voting rights held in issuer (8.A + 8.B) viiResulting situation on the date on which threshold was crossed or reached29.9029.94,627,741Position of previous notification (if applicable)N/AN/AN/A8. Notified details of the resulting situation on the date on which the threshold was crossed or reached viiiA: Voting rights attached to sharesClass/type ofsharesISIN code (if possible)Number of voting rights ix% of voting rightsDirect(DTR5.1)Indirect (DTR5.2.1)Direct(DTR5.1)Indirect(DTR5.2.1)Ordinary shares of €1.00 each under DTR 5.2.1(e)ISIN: GB00BMCLYF7901,961,074012.7%Ordinary shares of €1.00 each under DTR 5.2.1(a)ISIN: GB00BMCLYF7902,666,667017.2%SUBTOTAL 8. A4,627,74129.9%B 1: Financial Instruments according to DTR5.3.1R (1) (a)Type of financial instrumentExpirationdate xExercise/Conversion Period xiNumber of voting rights that may be acquired if the instrument is exercised/converted.% of voting rightsSUBTOTAL 8. B 1B 2: Financial Instruments with similar economic effect according to DTR5.3.1R (1) (b)Type of financial instrumentExpirationdate xExercise/Conversion Period xiPhysical or cash Settlement xiiNumber of voting rights % of voting rightsSUBTOTAL 8.B.29. Information in relation to the person subject to the notification obligation (please mark the applicable box with an “X”)Person subject to the notification obligation is not controlled by any natural person or legal entity and does not control any other undertaking(s) holding directly or indirectly an interest in the (underlying) issuer xiiiFull chain of controlled undertakings through which the voting rights and/or thefinancial instruments are effectively held starting with the ultimate controlling natural person or legal entity (please add additional rows as necessary) xivXName xv% of voting rights if it equals or is higher than the notifiable threshold% of voting rights through financial instruments if it equals or is higher than the notifiable thresholdTotal of both if it equals or is higher than the notifiable thresholdChain 1 in respect of the Prudential Assurance Company LimitedM&G plc 12.7%12.7%M&G Group Regulated Entity Holding Company Limited12.7%12.7%M&G Group Limited12.7%12.7%M&G FA Limited12.7%12.7%M&G Investment Management Limited 12.7%12.7%Chain 2 in respect of Fort Aggregator LP: Elevage Medical Technologies Holdings, LLC 17.2%17.2%Elevage Medical Technologies GP, LLC 17.2%17.2%Fort Aggregator, LP 17.2%17.2%10. In case of proxy voting, please identify:Name of the proxy holderThe number and % of voting rights heldThe date until which the voting rights will be held11. Additional information xviFort Aggregator, LP and the Prudential Assurance Company Limited have concluded pursuant to DTR 5.2.1(a). As such, the disclosure in sections 7, 8 and 9 of this form reflects their aggregated position. A separate notification will be made on behalf of Elevage Medical Technologies Holdings, LLC in respect of Fort Aggregator, LP’s shareholding. Place of completionLondon, United KingdomDate of completion15 November 2024