ANNUAL MEETING OF SHAREHOLDERS TO BE HELD ON MAY 5, 2021 NOTICE OF ANNUAL MEETING OF SHAREHOLDERS and MANAGEMENT PROXY CIRCULAR This Notice and Management Proxy Circular, along with accompanying materials, require your i

MEETING OF SHAREHOLDERS

BE HELD ON MAY 5, 2021

OF ANNUAL MEETING OF SHAREHOLDERS

Notice and Management Proxy Circular,

with accompanying materials, require your immediate attention.

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

VOTE IS IMPORTANT. PLEASE VOTE TODAY.

OF ANNUAL MEETING OF SHAREHOLDERS

IS HEREBY GIVEN that the annual meeting (the "Meeting") of shareholders of Aeterna Zentaris Inc. (the "Corporation"

or "Aeterna Zentaris") will be held on Wednesday, May 5, 2021 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/AEZS2021.

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

Meeting will be held virtually via 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/AEZS2021 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 Wednesday, May 5, 2021. 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/AEZS2021, 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

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 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 April

5, 2021 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. If you vote by mail, your vote must be received before 5:00 p.m. (Eastern time) on Monday, May 3,

2021. If you vote by telephone or Internet, your vote must be received before 5:00 p.m. (Eastern time) on Tuesday, May 4, 2021.

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 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 Wednesday, May 5, 2021 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/AEZS2021. 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 April 5, 2021 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, 2020: 1.000 = U.S.$1.140 and CAN$1.000 = U.S.$0.745; for the financial

year ended December 31, 2019: 1.000 = U.S.$1.120 and CAN$1.000 = U.S.$0.754; and for the financial year ended December 31,

2018: 1.000 = U.S.$1.181 and CAN$1.000 = U.S.$0.772.

2 - INFORMATION CONCERNING VOTING AT THE MEETING

Your Vote is Important

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 shareholder.

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 phone line the day of the Meeting to attend the Meeting live, submit your questions and submit your vote while the Meeting

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.

Vote in Advance of the Meeting - Voting by Proxy

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:

you are using mail, your 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 Monday, May 3, 2021

(Eastern time). For all other methods, you must have voted before 5:00 p.m. on Tuesday, May 4, 2021, (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.

Voting at the 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, whether you are a registered or non-registered shareholder, 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/AEZS2021 and check-in using the control