UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the Securities

Exchange Act of 1934 (Amendment No.           )

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☐ Definitive Proxy Statement

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Oncternal Therapeutics

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ONCTERNAL therapeutics Important Notice Regarding the Availability of Proxy Materials for the Stockholder Meeting to be held on June 11, 2020, for Oncternal Therapeutics, Inc. This is not a ballot. You cannot use this notice to vote these shares. This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. We encourage you to access and review all of the important information contained in the proxy materials before voting. To view the proxy statement and annual report, go to www.proxydocs.com/ONCT. To submit your proxy while visiting this site, you will need the 12 digit control number in the box below. Under United States Securities and Exchange Commission rules, proxy materials do not have to be delivered in paper. Proxy materials can be distributed by making them available on the Internet. We have chosen to use these procedures for our 2020 Annual Meeting and need YOUR participation. If you want to receive a paper or e-mail copy of the proxy materials, you must request one. There is no charge to you for requesting a copy. In order to receive a paper package in time for this year’s annual meeting, please make this request on or before June 1, 2020. For a Convenient Way to VIEW Proxy Materials and VOTE Online go to: www.proxydocs.com/ONCT Proxy Materials Available to View or Receive: 1. Proxy Statement 2. Annual Report Printed materials may be requested by one of the following methods: INTERNET www.investorelections.com/ONCT You must use the 12 digit control number located in the shaded gray box below. TELEPHONE (866) 648-8133 *E-MAIL paper@investorelections.com * If requesting material by e-mail, please send a blank e-mail with the 12 digit control number (located below) in the subject line. No other requests, instructions or other inquiries should be included with your e-mail requesting material. ACCOUNT NO. SHARES Oncternal Therapeutics, Inc., Notice of Annual Meeting   Date: 11 June 2020 Time: 8:00 a.m., Pacific Place: Annual Meeting to be held live via the Internet - please visit www.proxydocs.com/ONCT for more details. ONCTERNAL therapeutics The purpose of the Annual Meeting is to take action on the following proposals: The Board of Directors recommends that you vote “FOR” the following: The Board of Directors recommends that you vote “FOR” the following: 2. Proposal 2 - Ratification of the appointment of BDO USA, LLP as our independent registered public accounting firm for the year ending December 31, 2020. 3. Proposal 3 - Approve, on an advisory basis, the compensation of our named executive officers as disclosed in the proxy statement pursuant to the compensation disclosure rules of the Securities and Exchange Commission. NOTE: Also includes authorization to vote upon such other business as may properly come before the meeting or any adjournment or postponement thereof. TO ATTEND the Annual Meeting of Oncternal Therapeutics, Inc., please visit www.proxydocs.com/ONCT for virtual meeting registration details. The control number located in the shaded gray box will be required to register. 1. Proposal 1 - Election of Directors Nominees 01 Daniel L. Kisner, M.D. 02 William R. LaRue 03 Charles P. Theuer, M.D., Ph.D. Date: 11 June 2020 Time: 8:00 a.m., Pacific Place: Annual Meeting to be held live via the Internet - please visit www.proxydocs.com/ONCT for more details. Oncternal Therapeutics, Inc., Notice of Annual Meeting Proxy Materials Available to View or Receive: 1. Proxy Statement 2. Annual Report For a Convenient Way to VIEW Proxy Materials and VOTE Online go to: www.proxydocs.com/ONCT