Celyad Oncology SA — Proxy Solicitation & Information Statement 2020

Apr 3, 2020

Translation for information purposes only

CELYAD SA Listed limited liability company

Rue Edouard Belin, 2 1435 Mont-Saint-Guibert LER Nivelles 0891.118.115

INFORMATION CONCERNING THE RIGHTS OF SHAREHOLDERS PURSUANT TO ARTICLES ARTICLE 7:130 OF THE CODE OF COMPANIES AND ASSOCIATIONS ON THE OCCASION OF THE SHAREHOLDERS' MEETING OF THE COMPANY TO BE HELD ON 5 MAY 2020 AT 3PM AT THE COMPANY'S REGISTERED OFFICE

1. RIGHT OF SHAREHOLDERS TO INCLUDE ITEMS ON THE AGENDA AND TO SUBMIT DECISIONS' PROPOSALS

In accordance with the article 7:130 of the Code of Companies and Associations, one or more shareholders holding together at least 3% of the share capital may request the inclusion of items on the agenda to be addressed at the general meeting, and submit decisions' proposals concerning items to be addressed or included on the agenda.

The shareholder(s) exercising this right must meet the following two conditions in order for their request to be addressed at the general meeting:

• prove that it/they still hold(s) the abovementioned required percentage on the request date (either by way of a certificate mentioning the registration of the corresponding shares on the company's share register, or by way of an attest of a settlement institution or a certified account holder setting out the number of corresponding dematerialised shares registered in its accounts under the name of the shareholder, and
• prove that it/they is/are still shareholder(s) for up to 3% of the company's share capital at the record date (21 April 2020 at midnight (CET)).

Shareholders may then exercise their right by submitting (i) the draft new items for the agenda, and/or (ii) the draft proposals for resolution to be reflected in the agenda. Items to be included on this agenda and/or decisions' proposals must be sent to the company on 10 April 2020 at the latest by email to investors@celyad.com or by ordinary mail marked for the attention of Celyad, Mr Philippe Dechamps, Chief Legal Officer, rue Edouard Belin 2, B-1435 Mont-Saint-Guibert.

The company will acknowledge receipt of the requests sent by email or by mail to the address set out above by the shareholder within 48 hours after receipt.

The revised agenda will be published on 17 April at the latest (on the company's website at www.celyad.com, in the Belgian Official Gazette and in the press) if one or more requests to include new items or proposals for decisions on the agenda have been received within the aforementioned deadline.

Further information in relation to the abovementioned rights and the modalities for exercising them are available on the company's website (www.celyad.com).

2. RIGHT OF SHAREHOLDERS TO ASK WRITTEN QUESTIONS

Shareholders have the right to ask questions in writing to the directors prior to the shareholders' meeting that will be held on 5 May 2020.

The exercise of this right is subject to the fulfilment of the following two conditions:

• being a shareholder of the company at the record date (21 April 2020 at midnight (CET)); and
• having informed the company of the intent to participate in the general meeting, pursuant to the provisions set out in the convening notice.

These questions can be asked prior to the shareholders' meeting by email to investors@celyad.com or by mail marked for the attention of Celyad, Mr Philippe Dechamps, Chief Legal Officer, rue Edouard Belin 2, B-1435 Mont-Saint-Guibert.

These questions must be received on 27 April 2020 at 5pm (CET) at the latest.

In accordance with applicable legal provisions, the directors answer questions that are asked by the shareholders during the meeting or that have been asked in writing prior to the meeting, during the general meeting on their report or on the agenda. The auditor also answers questions asked by the shareholders at the meeting or in writing prior to the meeting on its report.

Further information in relation to the abovementioned rights and the modalities for exercising them are available on the company's website (www.celyad.com).