As filed with the Securities and Exchange Commission on October 20, 2025 Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-1 CELLECTAR BIOSCIENCES, INC. (Exact name of registrant as specified in its charter) (State or other jurisdiction of incorporation or organization) (Primary Standard Industrial Classification Delaware 2834 04-3321804 (I.R.S. Employer Identification No.) Code Number) REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 100 Campus Driv ...