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Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
Checkbox not checked   Rule 13d-1(b)
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X0202 SCHEDULE 13D/A 0001829126-26-004051 0001932843 XXXXXXXX LIVE 1 Ordinary Shares, nominal value (euro)0.01 per share 08/05/2026 false 0001874252 N5436L119 Quantum Cyber N.V. 200 Connecticut Ave. Suite 400 Norwalk CT 06854 David E. Lazar 646-768-8417 200 Connecticut Ave. Suite 400 Norwalk CT 06854 0001932843 N Lazar David E. PF N S1 477000000.00 0.00 477000000.00 0.00 477000000.00 N 94.3 IN (1) The figure reported in Items 7, 9, and 11 on this cover page includes (i) 55,057,500 Ordinary Shares of the Issuer, (ii) 196,942,500 Ordinary Shares of the Issuer issuable upon conversion of the Series D Preferred Shares of the Issuer, and (iii) 225,000,000 Ordinary Shares of the Issuer issuable upon conversion of the Series E Preferred Shares of the Issuer. (2) The percentage reported in Item 13 on this cover page is based on (i) 84,068,192 Ordinary Shares of the Issuer outstanding as of August 7, 2026, as confirmed by the Issuer on August 7, 2026, (ii) 196,942,500 Ordinary Shares of the Issuer issuable upon conversion of the Series D Preferred Shares of the Issuer, and (iii) 225,000,000 Ordinary Shares of the Issuer issuable upon conversion of the Series E Preferred Shares of the Issuer. Ordinary Shares, nominal value (euro)0.01 per share Quantum Cyber N.V. 200 Connecticut Ave. Suite 400 Norwalk CT 06854 The Issuer was formerly known as Mainz Biomed N.V. and changed its name to Quantum Cyber N.V. in April 2026. This Amendment No. 1 to the Schedule 13D (this "Amendment") amends and supplements the initial Schedule 13D filed by David E. Lazar (the "Reporting Person") with the U.S. Securities and Exchange Commission (the "SEC") on April 28, 2026 (together with this Amendment, the "Schedule 13D" or the "Statement"). Capitalized terms used but not defined in this Amendment shall have the meanings set forth in the Schedule 13D. Except as amended, restated and/or supplemented by this Amendment, the Schedule 13D remains unchanged. Item 2(b) of the Schedule 13D is hereby amended and restated as follows: "The principal business address of the Reporting Person is 200 Connecticut Ave. Suite 400, Norwalk, CT 06854." Item 3 of the Schedule 13D is hereby amended and supplemented as follows: "On August 5, 2026, the Reporting Person converted (i) 1,000,000 Series A Preferred Shares of the Issuer into 9,000,000 Ordinary Shares of the Issuer, (ii) 1,000,000 Series B Preferred Shares of the Issuer into 9,000,000 Ordinary Shares of the Issuer, (iii) 1,000,000 Series C Preferred Shares of the Issuer into 9,000,000 Ordinary Shares of the Issuer, and (iv) 124,700 Series D Preferred Shares of the Issuer into 28,057,500 Ordinary Shares of the Issuer (each of the foregoing for no additional consideration)." Item 5(a) of the Schedule 13D is hereby amended and restated as follows: "The aggregate number and percentage of the class of securities identified pursuant to Item 1 beneficially owned by the Reporting Person is stated in Items 11 and 13 on the cover page hereto." Item 5(b) of the Schedule 13D is hereby amended and restated as follows: "Number of shares as to which the Reporting Person has: (i) sole power to vote or to direct the vote: See Item 7 on the cover page hereto. (ii) shared power to vote or to direct the vote: See Item 8 on the cover page hereto. (iii) sole power to dispose or to direct the disposition of: See Item 9 on the cover page hereto. (iv) shared power to dispose or to direct the disposition of: See Item 10 on the cover page hereto." Item 5(c) of the Schedule 13D is hereby amended and restated as follows: "Except as disclosed in Item 3 of the Schedule 13D, which is incorporated herein by reference, no transactions in the Ordinary Shares of the Issuer were effected by the Reporting Person during the past 60 days or the since the most recent filing of Schedule 13D, whichever is less." Lazar David E. /s/ David E. Lazar David E. Lazar 08/07/2026