Celyad Oncology SA — Major Shareholding Notification 2013

Jul 12, 2013

Regulated information July 12, 2013 – 18:00 CET

Information on the total number of voting rights and shares

(Article 15 of the Law of 2 August 2007)

Transparency Notification Tolefi SA Participatie Maatschappij Vlaanderen NV, SRIW SA / SA SOFIPOLE and Mayo Foundation for Medical Research and Education

(Article 14 of the Law of 2 August 2007)

Mont-Saint-Guibert, Belgium, 11 July, 2013 - The biotechnology company, Cardio3 BioSciences SA (Cardio3 BioSciences), a leader in the discovery and development of regenerative, protective and reconstructive therapies for the treatment of cardiac diseases, today announces it has received a transparency declaration from Tolefi SA, Participatie Maatschappij Vlanderen (PMV) NV, Sofipole SA and Mayo Foundation for Medical Education and Research in accordance with the Belgian Law of 2nd May 2007 concerning disclosure of major holdings in issuers whose shares are admitted to trading on a Belgian regulated market.

As of today, the Company's share capital amounts to EUR 21,412,720.43 and is represented by a total 6,125,567 shares (each share given one voting right).

1. Transparency notification from Tolefi SA

Cardio3 BioSciences received on July 11, 2013 notification of transparency arising from Tolefi SA having passed, on July 9, 2013, the 35% threshold.

• Reason for notification: an ownership interest at the time of the IPO
• Notification by a parent company or controlling person.
• Person (s) holding (s) notification:

Name	Address
Tolefi SA	TOLEFI SA Drève of Carloo 27, 1180 Brussels
Serge GOBLET	48 Golf Avenue, 1640 Rhode Saint Genese
Isabelle THOUMYRE	48 Golf Avenue, 1640 Rhode Saint Genese

Voting rights	Previous notification	Post transaction
	# voting rights	# voting rights		% voting rights
Holders of voting rights		Attached to shares	Non related securities	Attached to shares	Non related securities
Tolefi SA	N/A	2,267,844	-	37.02%	-
Serge Goblet		-	-	0.00%	-
Isabelle Thoumyre		-	-	0.00%	-
	TOTAL	2,267,844	-	37.02%	-

Tolefi SA is a family holding company 100% owned by Mr. Serge Goblet and his wife Isabelle Thoumyre.

The company also holds 2,504 warrants giving 2504 voting rights.

2. Transparency notification from Participatie Maatschappij Vlanderen NV

Cardio3 BioSciences received on July 10 2013, a transparency notification from Participatie Maatschappij Vlanderen NV, having passed, on July 5, 2013, the 5% threshold.

• Reason for notification: an ownership interest at the time of the IPO
• Notification by a parent company or controlling person.
• Person (s) holding (s) notification

Name	Address
Participatiemaatschappij Vlaanderen NV (PMV NV)	Oude Graanmarkt 63, 1000 Brussels
PMV-TINA Comm VA	Oude Graanmarkt 63, 1000 Brussels
Het Vlaams Gewest	Martelaarsplein 19, 1000 Brussels

	Previous	Post transaction
Voting rights	notification

	# voting rights	# voting rights		% voting rights
Holders of voting rights		Attached to shares	Non related securities	Attached to shares	Non related securities
PMV-TINA Comm VA	N/A	570.571	-	9,31%	-
Het Vlaams Gewest		0	-	0,00%	-
Participatiemaatschap pij Vlaanderen NV (PMV NV)		0	-	0,00%	-
	TOTAL	570.571	-	9,31%	-

Participatiemaatschappij Vlaanderen NV controls PMV-Tina Comm VA.

3. Transparency notification from SRIW SA/Sofipole SA

Cardio3 BioSciences, received on July 9 2013, a transparency notification from SRIW SA/Sofipole, having passed, on July 5, 2013, the 10% threshold.

• Reason for notification: an ownership interest at the time of the IPO
• Notification by a parent company or controlling person.
• Person (s) holding (s) notification

Name	Address
S.R.I.W SA	avenue Maurice Destenay 13, 4000 Liège
SOFIPOLE SA	avenue Maurice Destenay 13, 4000 Liège

Voting rights	Previous notification	Post the transaction
	# voting rights	# voting rights % voting rights
Holders of voting rights		Attached to shares	Non related securities	Attached to shares	Non related securities
SRIW SA	N/A	290,526	-	4.74%	-
SOFIPOLE SA		370,646	-	6.05%	-
	TOTAL	661,172	-	10.79%	-

The Walloon Region owns 98.65% of SRIW SA, which owns 60% of shares in SOFIPOLE SA.

4. Transparency notification from Mayo Foundation for Medical Education and Research

Cardio3 BioSciences received July 9, 2013 a transparency notification from the Mayo Foundation for Medical Education and Research, having passed on July 5, 2013, the 5% threshold.

• Reason for notification: an ownership interest at the time of the IPO
• Notification by a parent company or controlling person.
• Person (s) holding (s) notification

Name	Address
Mayo Foundation for Medical Education	200 First Street SW, Rochester, MN 55906-001 (United
and Research	States of America)

Voting rights	Previous notification	Post transaction
	# voting rights	# voting rights		% voting rights
Holders of voting rights		Attached to shares	Non related securities	Attached to shares	Non related securities
Mayo Foundation for Medical Education and Research	N/A	340,947	-	5.57%	-
	TOTAL	340,947	-	5.57%	-

Mayo Foundation for Medical Education and Research is not a controlled entity.

*** END ***

For more information contact:

Cardio3 BioSciences

www.c3bs.com

Dr Christian Homsy, CEO Anne Portzenheim, Communication Manager

Citigate Dewe Rogerson David Dible/Chris Gardner/Malcolm Robertson

Tel : +32 10 39 41 00 aportzenheim@c3bs.com

Tel : +44 (0) 207 638 9571 david.dible@citigatedr.co.uk