As filed with the Securities and Exchange Commission on December 16, 2025 Registration No. 333-291852 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-1 Amendment No. 1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Edison Oncology Holding Corp. (Exact name of registrant as specified in its charter) (State or other jurisdiction of incorporation or organization) Nevada 2836 83-1614120 (Primary Standard Industrial Classification Code Number) 3475 Edison Way, Suite R Menl ...