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) i
1a. Identity of the issuer or the underlying issuer of existing shares to which voting rights are attached ii:			4basebio PLC
1b. Please indicate if the issuer is a non-UK issuer  (please mark with an “X” if appropriate)
Non-UK issuer
2. Reason for the notification (please mark the appropriate box or boxes with an “X”)
An acquisition or disposal of voting rights						X
An acquisition or disposal of financial instruments
An event changing the breakdown of voting rights
Other (please specify) iii:
3. Details of person subject to the notification obligation iv
Name			Franciscus De Busschere
City and country of registered office (if applicable)			Cambridge, UK
4. Full name of shareholder(s) (if different from 3.) v
Name
City and country of registered office (if applicable)
5. Date on which the threshold was crossed or reached vi:			13 November 2024
6. Date on which issuer notified (DD/MM/YYYY):			13 November 2024
7. 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) vii
Resulting situation on the date on which threshold was crossed or reached	3.47%	N/A		3.47%	537,255
Position of previous notification (if applicable)	4.19%	N/A		4.19%

8. Notified details of the resulting situation on the date on which the threshold was crossed or reached viii
A: Voting rights attached to shares
Class/type of sharesISIN code (if possible)		Number of voting rights ix					% of voting rights
		Direct(DTR5.1)		Indirect (DTR5.2.1)			Direct(DTR5.1)		Indirect(DTR5.2.1)
GB00BMCLYF79		537,255		N/A			3.47%		N/A
SUBTOTAL 8. A		537,255					3.47%
B 1: Financial Instruments according to DTR5.3.1R (1) (a)
Type of financial instrument		Expiration date x	Exercise/ Conversion Period xi			Number of voting rights that may be acquired if the instrument is exercised/converted.			% of voting rights
			SUBTOTAL 8. B 1
B 2: Financial Instruments with similar economic effect according to DTR5.3.1R (1) (b)
Type of financial instrument	Expiration date x		Exercise/ Conversion Period xi		Physical or cash Settlement xii			Number of voting rights	% of voting rights
					SUBTOTAL 8.B.2

9. 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 xiii				X
Full chain of controlled undertakings through which the voting rights and/or the financial instruments are effectively held starting with the ultimate controlling natural person or legal entity (please add additional rows as necessary) xiv
Name 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 threshold	Total of both if it equals or is higher than the notifiable threshold
10. In case of proxy voting, please identify:
Name of the proxy holder
The number and % of voting rights held
The date until which the voting rights will be held
11. Additional information xvi

Place of completion	London, UK
Date of completion	15 November 2024

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