315 Sigma Drive

Summerville, South Carolina 29486

VIA EDGAR

November 27, 2018

Sisi Cheng/Lisa Vanjoske

Division of Corporation Finance

Office of Healthcare & Insurance

United States Securities and Exchange Commission

Washington, D.C. 20549

RE:Æterna Zentaris Inc.

Form 20-F for the Year Ended December 31, 2017

Filed March 28, 2018

Form 6-K for the Month of May 2018

Filed May 7, 2018

File No. 001-38064

Dear Ms. Cheng and Ms. Vanjoske:

We are writing in response to comments from the Staff of the Division of Corporation Finance, Office of Healthcare and Insurance (“Staff”) of the Securities and Exchange Commission (“Commission”) contained in your November 7, 2018 letter (the “Comment Letter”) concerning Æterna Zentaris Inc.’s (“Company”) above-referenced filings (such filings, the “financial statements”).

The Comment Letter raises further questions regarding the Company’s October 9, 2018 response to the Staff’s September 13, 2018 letter (“October 9 Response”), which are set out in bullets within Question 1 of the Comment Letter.

Thank-you for your time on November 13, 2018 and on November 15, 2018 to discuss and clarify the areas where further focus needed to be provided by the Company in its response to the Comment Letter.

At this time we are requesting an extension to file our final response to the Comment Letter on December 3, 2018. If you have any questions, I can be contacted at (416) 254-2192 or by email at lauld@aezsinc.com.

Thank you for your attention to this matter.

Very truly yours,

/s/ Leslie Auld

Leslie Auld

Chief Financial Officer and SVP

Æterna Zentaris

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