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Table of Contents ㅁ UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 FORM 10 - K ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the year ended December 31 , 2020 OR TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from Commission File Number 001-39069 to Delaware Aprea Therapeutics , Inc. ( Exact name of registrant as specified in its charter ) 84-2246769 ( I.R.S. Employer Identification No. ) 02116 ( Zip code ) ( State or other jurisdiction of incorporation or organization ) 535 Boylston Street Boston , Massachusetts ( Address of principal executive offices ) ( 617 ) 463-9385 ( Registrant's telephone number , including area code ) Not Applicable ( Former name , former address and former fiscal year , if changed since last report ) Securities registered pursuant to Section 12 ( b ) of the Act : Name of exchange Title of each class Common stock , par value $ 0.001 per share Trading Symbol APRE on which registered : NASDAQ Global Select Market Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes No Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 ( d ) of the Act . Yes □ No Indicate by check mark whether the registrant ( 1 ) has filed all reports required to be filed by Section 13 or 15 ( d ) of the Securities Exchange Act of 1934 during the preceding 12 months ( or for such shorter period that the registrant was required to file such reports ) , and ( 2 ) has been subject to such filing requirements for the past 90 days . Yes No □ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S - T ( $ 232.405 of this chapter ) during the preceding 12 months ( or for such shorter period that the registrant was required to submit such files ) . Yes No □ Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , a smaller reporting company , or an emerging growth company . See the definitions of " large accelerated filer , " " accelerated filer , " " smaller reporting company , " and " emerging growth company " in Rule 12b - 2 of the Exchange Act . Large accelerated filer Non - accelerated filer Accelerated filer Smaller reporting company Emerging growth company If an emerging growth company , indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13 ( a ) of the Exchange Act . Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404 ( b ) of the Sarbanes - Oxley Act ( 15 U.S.C. 7262 ( b ) ) by the registered public accounting firm that prepared or issued its audit report . Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Exchange Act ) . Yes □ No The aggregate market value of the voting stock held by non - affiliates of the registrant as of June 30 , 2020 was approximately $ 263.8 million . There were 21,186,827 shares of the registrant's common stock , $ 0.001 par value , outstanding as of March 16 , 2021 . DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant's definitive proxy statement for its 2021 Annual Meeting of Stockholders ( the " Proxy Statement " ) , to be filed within 120 days of the registrant's fiscal year ended December 31 , 2020 , are incorporated by reference in Part III of this Annual Report on Form 10 - K . Except with respect to information specifically incorporated by reference in this Annual Report on Form 10 - K , the Proxy Statement is not deemed to be filed as part of this Annual Report on Form 10 - K .