ANNUAL GENERAL AND SPECIAL MEETING OF SHAREHOLDERS TO BE HELD ON JUNE 21, 2022 NOTICE OF ANNUAL GENERAL AND SPECIAL MEETING OF SHAREHOLDERS and MANAGEMENT PROXY CIRCULAR This Notice and Management Proxy Circular, along w

GENERAL AND SPECIAL MEETING OF SHAREHOLDERS

BE HELD ON JUNE 21, 2022

OF ANNUAL GENERAL AND SPECIAL MEETING OF SHAREHOLDERS

Notice and Management Proxy Circular,

with accompanying materials, require your immediate attention.

BOARD OF DIRECTORS RECOMMENDS A VOTE IN FAVOUR OF ALL PROPOSED RESOLUTIONS.

VOTE IS IMPORTANT. PLEASE VOTE TODAY.

OF ANNUAL GENERAL AND SPECIAL MEETING OF SHAREHOLDERS

IS HEREBY GIVEN that the annual general and special meeting (the "Meeting") of shareholders of Aeterna Zentaris

Inc. (the "Corporation" or "Aeterna Zentaris") will be held on Tuesday, June 21, 2022, at 10:00

a.m. (Eastern time). The Meeting will be a virtual meeting conducted via live audio webcast. Shareholders can access the Meeting by visiting

www.virtualshareholdermeeting.com/AEZS2022. The Meeting is being held for the following purposes:

record date for the determination of shareholders of Aeterna Zentaris entitled to receive notice of and to vote at the Meeting is May

Meeting will be held virtually on the Internet. Shareholders will not be able to attend the Meeting in person. Shareholders (both registered

and non-registered) who choose to attend the Meeting will do so by accessing a live audio webcast of the Meeting via the Internet. To

attend the Meeting, shareholders will need to visit www.virtualshareholdermeeting.com/AEZS2022 and check-in using the control

number included either on your proxy form or voting instruction form, as applicable. The Meeting platform is fully supported across browsers

and devices running the most updated version of applicable software plugins. You should ensure you have a strong, preferably high-speed,

Internet connection wherever you intend to participate in the Meeting. The Meeting will begin promptly at 10:00 a.m. (Eastern time) on

Tuesday, June 21, 2022. Online check-in will begin 15 minutes prior, at 9:45 a.m. (Eastern time). You should allow ample time for online

check-in procedures.

www.virtualshareholdermeeting.com/AEZS2022, shareholders will be able to listen to the Meeting live, submit questions and submit

their vote while the Meeting is being held. As a response to the global pandemic of the novel coronavirus, we believe that hosting the

Meeting virtually will minimize the health risk that may be associated with large gatherings, while enabling increased shareholder attendance

from locations around the world and encouraging more active shareholder engagement and participation at the Meeting.

you are unable to attend the Meeting or if you wish to vote in advance of the Meeting, please carefully follow the instructions on the

proxy or voting instruction form. Shareholders that hold their common shares with a bank, broker or financial intermediary and wish to

vote at the Meeting must carefully follow the instructions provided by their intermediary. In order to be effective, proxies must be

received by the Chair of the Meeting no later than 48 hours (if voting by mail) or 24 hours (if voting by telephone or Internet) prior

to the close of business on the date of the Meeting or any adjournment or postponement thereof. The time limit for the deposit of proxies

may be waived by the Chair of the Meeting without notice. If you are attending the Meeting, please log-on to the virtual meeting platform

in advance to ensure that your vote will be counted.

shareholders of Aeterna Zentaris, it is very important that you read the management proxy circular of the Corporation dated May 16, 2022

and other Meeting materials carefully. Even if you intend to attend the Meeting, it is recommended that you vote in advance by telephone

or Internet to ensure that your vote is received before the Meeting. To cast your vote by telephone or Internet, please have your

proxy card or voting instruction form in hand and carefully follow the instructions contained therein. Your telephone or Internet vote

authorizes the named proxies to vote your common shares in the same manner as if you mark, sign and return your proxy card. To be valid,

your vote must be received before 5:00 p.m. (Eastern time) on Friday, June 17, 2022.

order of the Board of Directors,

management proxy circular (this "Circular") is being furnished in connection with the solicitation of proxies

by and on behalf of the management of Aeterna Zentaris Inc. (the "Corporation", "Aeterna Zentaris",

"we" or "our") for use at the annual general and special meeting of our shareholders

(the "Meeting") and any adjournment(s) or postponement(s) thereof. No person has been authorized to give any

information or to make any representation in connection with any matters to be considered at the Meeting other than those contained in

this Circular and, if given or made, any such information or representation must not be relied upon as having been authorized.

Meeting will be held on Tuesday, June 21, 2022 at 10:00 a.m. (Eastern time). The Meeting will be a virtual meeting conducted via live

audio webcast. Shareholders will not be able to attend the Meeting in person. Shareholders (both registered and non-registered) can access

the Meeting by visiting www.virtualshareholdermeeting.com/AEZS2022. A summary of the information that shareholders will need to

attend the Meeting online is provided below.

may solicit proxies by telephone, Internet or mail. We will bear the entire cost of any such solicitation. We may also reimburse brokers

and other persons holding our common shares (the "Common Shares") in their names, or in the names of nominees, for

their costs incurred in sending proxy materials to registered or non-registered owners and obtaining their proxies or voting instructions.

contained in this Circular is given as of May 16, 2022 unless otherwise specifically stated. Our directors and executive officers are

generally paid in their home country currency. Unless otherwise indicated, all compensation information included in this Circular is

presented in U.S. dollars and, to the extent a director or officer has been paid in a currency other than U.S. dollars, the amounts have

been converted from such person's home country currency to U.S. dollars based on the following annual average exchange rates: for

the financial year ended December 31, 2021: 1.000 = U.S.$1.18 and CAN$1.000 = U.S.$0.79; for the financial year ended December

31, 2020: 1.000 = U.S.$1.140 and CAN$1.000 = U.S.$0.745; and for the financial year ended December 31, 2019: 1.000 = U.S.$1.120

and CAN$1.000 = U.S.$0.754.

2 - INFORMATION CONCERNING VOTING AT THE MEETING

a shareholder, it is very important that you read the following information on how to vote your Common Shares, either by proxy or in

attendance at the Meeting. These materials are being sent to both our registered and non-registered shareholders. Please return your

proxy as specified in this Circular and in the form of proxy or voting instruction form.

you are eligible to vote and your Common Shares are either registered in your name or are held in the name of a nominee (non-registered),

you can vote your Common Shares at the Meeting or by proxy in advance of the Meeting, as explained below. Voting by proxy in advance

of the Meeting is the easiest way to vote your shares. The same procedures apply whether you are a registered shareholder or non-registered

are a registered shareholder if your name appears on your share certificate or your Direct Registration System ("DRS")

confirmation. If you are a registered shareholder, you will receive a proxy form containing the relevant details concerning the business

of the Meeting, including a control number that must be used to: vote by proxy in advance of the Meeting or join the live webcast and

telephone line the day of the Meeting to attend the Meeting live; submit your questions; and submit your vote while the Meeting is being

your Common Shares are not registered in your name and are held in the name of a nominee such as a trustee, financial institution or

securities broker, you are a non-registered shareholder. If your Common Shares are listed in an account statement provided to you by

your broker, those Common Shares will, in all likelihood, not be registered in your name. Such Common Shares will more likely be registered

under the name of your broker or an agent of that broker. Without specific instructions, brokers and their agents or nominees are prohibited

from voting shares for the broker's client. If you are a non-registered shareholder, you will receive a voting instruction form

containing the relevant details concerning the business of the Meeting, including a control number that must be used to vote by proxy

in advance of the Meeting or join the live webcast and phone line the day of the Meeting to attend the Meeting live, submit your questions

and submit your vote while the Meeting is being held.

are the different ways in which you can give your voting instructions, details of which are found in the proxy form or voting instruction

form, as applicable, accompanying this Circular:

duly completed proxy form or voting instruction form, as applicable, must have been received by our proxy tabulator with sufficient time

for your vote to be processed, and in all cases, no later than 5:00 p.m. on Friday, June 17, 2022 (Eastern time) or, if the Meeting

is adjourned or postponed, by no later than 5:00 p.m. (Eastern time) on the business day prior to the day fixed for the adjourned

or postponed Meeting.

you wish to vote at the Meeting, you do not need to complete or return your proxy form or voting instruction form, as applicable. The

day of the Meeting, all shareholders (registered and non-registered) will be able to vote via the live webcast by completing a ballot

online during the Meeting.

attend the Meeting, shareholders will need to visit www.virtualshareholdermeeting.com/AEZS2022 and check-in using the control

number included either on your proxy form or voting instruction form, as applicable. The Meeting platform is fully supported across Internet

browsers and devices running the most updated version of applicable software plugins. You should ensure you have a strong, preferably

high-speed, Internet connection from wherever you intend to participate in the Meeting. The Meeting will begin promptly at 10:00 a.m.

(Eastern time) on Tuesday, June 21, 2022. Online check-in will begin 15 minutes prior, at 9:45 a.m. (Eastern time). You should allow

ample time for online check-in procedures.

you wish to appoint someone as proxy to vote your shares for you at the Meeting during the live webcast, please follow the instructions

found on either your proxy form or voting instruction form, as applicable. You will need to create a unique eight character identification