Additional Proxy Soliciting Materials (Form DEFA14A)

*Please check the meeting materials for any special requirements for meeting attendance. Smartphone users Point your camera here and vote without entering a control number For complete information and to vote, visit www.ProxyVote.com Control # V95381-P51739 NEXTCURE, INC. 9000 VIRGINIA MANOR ROAD SUITE 200 BELTSVILLE, MD 20705 Your Vote Counts! NEXTCURE, INC. 2026 Annual Meeting to Be Held on June 18, 2026 Vote by June 17, 2026 11:59 PM ET You invested in NEXTCURE, INC. and it's time to vote! You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy materials for the stockholder meeting to be held on June 18, 2026. Get informed before you vote View the Notice, Proxy Statement and Annual Report on Form 10-K online OR you can receive a free paper or email copy of the material(s) by requesting prior to June 4, 2026. If you would like to request a copy of the material(s) for this and/or future stockholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to [email protected]. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy. Vote Virtually During the Meeting* June 18, 2026 11:00 AM ET Virtually at: www.virtualshareholdermeeting.com/NXTC2026

Vote at www.ProxyVote.com Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click "Delivery Settings". Voting Items Board Recommends V95382-P51739 THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming stockholder meeting. Please follow the instructions on the reverse side to vote these important matters. 1. Election of two Class I Directors. Nominees: 1a. Anne Borgman, M.D. For 1b. John G. Houston, Ph.D. For 2. Ratification of the appointment of Ernst & Young LLP as the independent registered public accounting firm of NextCure, Inc. for the fiscal year ending December 31, 2026. For 3. Approval, on an advisory basis, of the compensation paid by Company to its named executive officers. For 4. Approval of an amendment and restatement of the Company's 2019 Omnibus Incentive Plan to, among other items, increase the number of shares of common stock authorized for issuance thereunder. For NOTE: In their discretion, the proxies are authorized to vote upon such other business as may properly come before the meeting.