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UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 FORM 40 - F ( Check one ) [ ] Registration statement pursuant to Section 12 of the Securities Exchange Act of 1934 or [ X ] Annual report pursuant to Section 13 ( a ) or 15 ( d ) of the Securities Exchange Act of 1934 For the fiscal year ended : December 31 , 2020 Commission File Number : 001-38064 AETERNA ZENTARIS INC . ( Exact name of Registrant as specified in its charter ) Ontario , Canada ( Province or other jurisdiction of incorporation or organization ) 2834 ( Primary Standard Industrial Classification Code Number ( if applicable ) ) 315 Sigma Drive Summerville , South Carolina 29486 ( 843 ) 900-3223 Not Applicable ( I.R.S. Employer Identification Number ( if applicable ) ) ( Address and telephone number of Registrant's principal executive offices ) Klaus Paulini , PhD President and Chief Executive Officer Aeterna Zentaris , Inc. , 315 Sigma Drive Summerville , South Carolina 29486 ( 843 ) 900-3211 ( Name , address ( including zip code ) and telephone number ( including area code ) of agent for service in the United States ) Securities registered or to be registered pursuant to Section 12 ( b ) of the Act : Title of each class Common Shares Trading Symbol ( s ) AEZS Name of each exchange on which registered The Nasdaq Stock Market Toronto Stock Exchange Securities registered or to be registered pursuant to Section 12 ( g ) of the Act : None Securities for which there is a reporting obligation pursuant to Section 15 ( d ) of the Act : None For annual reports , indicate by check mark the information filed with this Form : [ X ] Annual Information Form [ X ] Audited Annual Financial Statements Indicate the number of outstanding shares of each of the issuer's classes of capital or common stock as of the close of the period covered by the annual report : Common Shares outstanding as of December 31 , 2020 : 62,678,613