CLRBW / Cellectar Biosciences, Inc. Warrants expiring 8/20/2019 - SEC-arkiveringar, Årsredovisning, Fullmaktsutlåtande

PROSPECTUS Up to 51,998,413 Shares of Common Stock Offered by the Selling Stockholders CELLECTAR BIOSCIENCES, INC.

Filed Pursuant to Rule 424(b)(3) Registration No. 333-296036 PROSPECTUS Up to 51,998,413 Shares of Common Stock Offered by the Selling Stockholders CELLECTAR BIOSCIENCES, INC. This prospectus relates to the resale, from time to time by the selling stockholders named in this prospectus (the “selling stockholders”) of up to 51,998,413 shares of our common stock (the “Shares”), consisting of (i) up t

As filed with the Securities and Exchange Commission on May 29, 2026

As filed with the Securities and Exchange Commission on May 29, 2026 Registration No.

Security Type

Calculation of Filing Fee Tables S-1 Cellectar Biosciences, Inc. Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward

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

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 Filed by the Registrant x Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Definitive Proxy Stateme

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

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 Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Definitive Proxy Stateme

Security Type

Calculation of Filing Fee Tables S-1 Cellectar Biosciences, Inc. Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward

As filed with the Securities and Exchange Commission on May 19, 2026

As filed with the Securities and Exchange Commission on May 19, 2026 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 17, 2026 Cellectar Bioscience

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 17, 2026 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

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

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 Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy State

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q [mark one] ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: March 31, 2026 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-36598 CELLE

Cellectar Biosciences Reports First Quarter 2026 Financial Results and Provides Corporate Updates Announced Positive 12-month Follow-on Data for Iopofosine I 131 in relapsed/refractory Waldenström Macroglobulinemia (r/r WM) Completed Financing of up

Exhibit 99.1 Cellectar Biosciences Reports First Quarter 2026 Financial Results and Provides Corporate Updates Announced Positive 12-month Follow-on Data for Iopofosine I 131 in relapsed/refractory Waldenström Macroglobulinemia (r/r WM) Completed Financing of up to $140 Million to Support Initiation of Confirmatory Study of Iopofosine I 131 in r/r WM and Subsequent U.S. FDA Filing for Accelerated

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 14, 2026 Cellectar Bioscience

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 14, 2026 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

PLACEMENT AGENT COMMON STOCK PURCHASE WARRANT cellectar biosciences, inc.

Exhibit 4.5 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

SERIES A COMMON STOCK PURCHASE WARRANT cellectar biosciences, inc.

Exhibit 4.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

PLACEMENT AGENCY AGREEMENT

Exhibit 10.4 PLACEMENT AGENCY AGREEMENT May 4, 2026 Ladenburg Thalmann & Co. Inc. 640 Fifth Avenue, 4th Floor New York, New York 10019 Ladies and Gentlemen: Introduction. Subject to the terms and conditions herein (this “Agreement”), Cellectar Biosciences, Inc., a Delaware corporation (the “Company”), hereby agrees to sell up to an aggregate of $35,000,000.00 of securities of the Company, includin

SECURITIES PURCHASE AGREEMENT

Exhibit 10.2 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of May 4, 2026, between Cellectar Biosciences, Inc., a Delaware corporation (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively, the “Purchasers”). WHEREAS, subject to the terms and conditio

REGISTRATION RIGHTS AGREEMENT

Exhibit 10.3 REGISTRATION RIGHTS AGREEMENT This Registration Rights Agreement (this “Agreement”) is made and entered into as of May 4, 2026, between Cellectar Biosciences, Inc., a Delaware corporation (the “Company”), and each of the several purchasers signatory hereto (each such purchaser, a “Purchaser” and, collectively, the “Purchasers”). This Agreement is made pursuant to the Securities Purcha

SECURITIES PURCHASE AGREEMENT

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of May 4, 2026, between Cellectar Biosciences, Inc., a Delaware corporation (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively, the “Purchasers”). WHEREAS, subject to the terms and conditio

SERIES C COMMON STOCK PURCHASE WARRANT cellectar biosciences, inc.

Exhibit 4.4 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

PRE-FUNDED COMMON STOCK PURCHASE WARRANT cellectar biosciences, inc.

Exhibit 4.1 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

CELLECTAR BIOSCIENCES, INC.

Exhibit 10.5 CELLECTAR BIOSCIENCES, INC. May 4, 2026 c/o Nantahala Capital Management, LLC 130 Main Street, 2nd Floor New Canaan, CT 06840 Re:         Director Designation Rights Ladies and Gentlemen: Subject to and in consideration of an investment in Cellectar Biosciences, Inc., a Delaware corporation (the “Company”), by funds and accounts managed by Nantahala Capital Management, LLC (“Nantahala

SERIES B COMMON STOCK PURCHASE WARRANT cellectar biosciences, inc.

Exhibit 4.3 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 4, 2026 Cellectar Biosciences,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 4, 2026 Cellectar Biosciences, Inc.

1,618,053 Shares of Common Stock

Filed Pursuant to Rule 424(b)(5) Registration No. 333-279731 PROSPECTUS SUPPLEMENT (To Prospectus Dated July 23, 2024) 1,618,053 Shares of Common Stock We are offering to certain investors 1,618,053 shares of our common stock, par value $0.00001 per share (the “Common Stock”). The offering price for each share of Common Stock is $2.65. In a concurrent private placement, we are also offering, to th

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1)

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended: December 31, 2025 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission File Numbe

Cellectar Biosciences Reports Financial Results for Year Ended 2025 and Provides Corporate Updates On track to submit Conditional Marketing Authorization for iopofosine I 131 to European Medicines Agency in Q3 2026 for potential 2027 EU commercializa

Exhibit 99.1 Cellectar Biosciences Reports Financial Results for Year Ended 2025 and Provides Corporate Updates On track to submit Conditional Marketing Authorization for iopofosine I 131 to European Medicines Agency in Q3 2026 for potential 2027 EU commercialization as a treatment for Waldenström Macroglobulinemia Initiated Phase 1b dose finding study for CLR 125 in Triple Negative Breast Cancer

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): March 4, 2026 Cellectar Bioscienc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): March 4, 2026 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended: December 31, 2025 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission File Number 001-36598 CELLECTA

PROSPECTUS Up to 2,096,188 Shares of Common Stock Offered by the Selling Stockholders CELLECTAR BIOSCIENCES, INC. Common Stock

Filed Pursuant to Rule 424(b)(3) Registration No. 333-290971 PROSPECTUS Up to 2,096,188 Shares of Common Stock Offered by the Selling Stockholders CELLECTAR BIOSCIENCES, INC. Common Stock This prospectus relates to the resale, from time to time by the selling stockholders named in this prospectus (the “selling stockholders”), of up to 2,096,188 shares of our common stock (the “Shares”) issuable up

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q [mark one] ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: September 30, 2025 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-36598 C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 13, 2025 Cellectar Biosc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 13, 2025 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commis

Cellectar Biosciences Reports Third Quarter 2025 Financial Results and Provides Corporate Update Expects to Submit Conditional Marketing Approval Application in Europe for Iopofosine I 131 in Refractory (post-BTKi) Waldenstrom’s Macroglobulinemia in

Exhibit 99.1 Cellectar Biosciences Reports Third Quarter 2025 Financial Results and Provides Corporate Update Expects to Submit Conditional Marketing Approval Application in Europe for Iopofosine I 131 in Refractory (post-BTKi) Waldenstrom’s Macroglobulinemia in 2026 Following Advice and Guidance from Scientific Advice Working Party (SAWP) Initiated Phase 1b Study of CLR 125 for TNBC Received Rare

As filed with the Securities and Exchange Commission on October 20, 2025

As filed with the Securities and Exchange Commission on October 20, 2025 Registration No.

Filing Fee Table

Calculation of Filing Fee Tables S-1 Cellectar Biosciences, Inc. Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 7, 2025 Cellectar Bioscienc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 7, 2025 Cellectar Biosciences, Inc.

CELLECTAR BIOSCIENCES, INC.

Exhibit 10.1 CELLECTAR BIOSCIENCES, INC. October 7, 2025 Holder of Common Stock Purchase Warrants issued on October 25, 2022, July 21, 2024 and July 2, 2025 Re: Exercise of Common Stock Purchase Warrants Dear Holder: Cellectar Biosciences, Inc. (the “Company”) is pleased to confirm our agreement regarding the exercise (the “Warrant Exercise”) of your (i) the Common Stock Purchase Warrants to purch

SERIES I COMMON STOCK PURCHASE WARRANT cellectar biosciences, inc.

Exhibit 4.1 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

SERIES II COMMON STOCK PURCHASE WARRANT cellectar biosciences, inc.

Exhibit 4.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

Cellectar Biosciences Announces European Medicines Agency (EMA) Confirms Eligibility to File for Conditional Marketing Authorization (CMA) for Iopofosine I 131 as a Treatment for Refractory (post-BTKi) Waldenstrom Macroglobulinemia (WM) Following Sci

Exhibit 99.1 Cellectar Biosciences Announces European Medicines Agency (EMA) Confirms Eligibility to File for Conditional Marketing Authorization (CMA) for Iopofosine I 131 as a Treatment for Refractory (post-BTKi) Waldenstrom Macroglobulinemia (WM) Following Scientific Advice and Guidance from Scientific Advice Working Party (SAWP) of EMA, Submission of CMA Application for Iopofosine I 131 as a T

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 6, 2025 Cellectar Bioscienc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 6, 2025 Cellectar Biosciences, Inc.

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q [mark one] ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: June 30, 2025 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-36598 CELLEC

Cellectar Biosciences Reports Second Quarter 2025 Financial Results and Provides a Corporate Update Intend to Pursue an NDA Submission to the U.S. FDA under Accelerated Approval Pathway for Iopofosine I 131 for the Treatment of Waldenstrom Macroglobu

Exhibit 99.1 Cellectar Biosciences Reports Second Quarter 2025 Financial Results and Provides a Corporate Update Intend to Pursue an NDA Submission to the U.S. FDA under Accelerated Approval Pathway for Iopofosine I 131 for the Treatment of Waldenstrom Macroglobulinemia (WM) Subject to Sufficient Funding and Once the Confirmatory Trial is Underway Continue to Work with the EMA Toward a Potential S

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 14, 2025 Cellectar Bioscie

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 14, 2025 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commissi

865,000 Class A Units with each Class A Unit consisting of (i) one (1) Share of Common Stock and (ii) one (1) Common Warrant to purchase one (1) Share of Common Stock 335,000 Class B Units with each Class B Unit consisting of (i) one (1) Pre-Funded W

Filed Pursuant to Rule 424(b)(4) Registration No. 333-288333 Prospectus 865,000 Class A Units with each Class A Unit consisting of (i) one (1) Share of Common Stock and (ii) one (1) Common Warrant to purchase one (1) Share of Common Stock 335,000 Class B Units with each Class B Unit consisting of (i) one (1) Pre-Funded Warrant to Purchase one (1) Share of Common Stock and (ii) one (1) Common Warra

CELLECTAR BIOSCIENCES, INC. 100 Campus Drive Florham Park, New Jersey 07932

CELLECTAR BIOSCIENCES, INC. 100 Campus Drive Florham Park, New Jersey 07932 June 30, 2025 VIA EDGAR Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Re: Cellectar Biosciences, Inc. Registration Statement on Form S-1/A Filed June 30, 2025 File No. 333-288333 Ladies and Gentlemen: Pursuant to Rule 461(a) under the Securities Act of 1933, as

Form of Common Warrant

Exhibit 4.2 COMMON STOCK PURCHASE WARRANT cellectar biosciences, inc. Warrant Shares: [] Initial Exercise Date: [], 2025 THIS COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, [] or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the date hereof (the “

Form of Pre-Funded Warrant

Exhibit 4.3 PRE-FUNDED COMMON STOCK PURCHASE WARRANT cellectar biosciences, inc. Warrant Shares: [] Initial Exercise Date: [], 2025 THIS PRE-FUNDED COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, [] or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after

Ladenburg Thalmann & Co. Inc. 640 Fifth Avenue, 4th Floor New York, New York 10019

Ladenburg Thalmann & Co. Inc. 640 Fifth Avenue, 4th Floor New York, New York 10019 June 30, 2025 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance Washington, DC 20549 Re: Cellectar Biosciences, Inc. Registration Statement on Form S-1 (Registration No. 333-288333) Concurrence in Acceleration Request Ladies and Gentlemen: Ladenburg Thalmann & Co. Inc. (“Ladenburg”),

Form of Representative Warrant

Exhibit 4.4 REPRESENTATIVE COMMON STOCK PURCHASE WARRANT cellectar biosciences, inc. Warrant Shares: [] Initial Exercise Date: [], 2025 THIS REPRESENTATIVE COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, [] or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on o

As filed with the Securities and Exchange Commission on June 30, 2025

As filed with the Securities and Exchange Commission on June 30, 2025 Registration No.

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Cellectar Biosciences, Inc.

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 26, 2025 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

Form of Warrant Agency Agreement

Exhibit 4.5 Cellectar Biosciences, Inc. and Equiniti Trust Company, LLC, as Warrant Agent Warrant Agency Agreement Dated as of [], 2025 WARRANT AGENCY AGREEMENT WARRANT AGENCY AGREEMENT, dated as of [], 2025 (“Agreement”), between Cellectar Biosciences, Inc., a Delaware corporation (the “Company”), and Equiniti Trust Company, LLC, a New York limited liability trust company (the “Warrant Agent”). W

As filed with the Securities and Exchange Commission on June 26, 2025

As filed with the Securities and Exchange Commission on June 26, 2025 Registration No.

Form of Underwriting Agreement

  Exhibit 1.1   [] SHARES of Common StOCK,   [] PRE-FUNDED WARRANTS EXERCISABLE INTO [] SHARES OF COMMON STOCK   and   [] COMMON Warrants EXERCISABLE INTO [] SHARES OF COMMON STOCK   CELLECTAR BIOSCIENCES, INC.   UNDERWRITING AGREEMENT   [], 2025   Ladenburg Thalmann & Co. Inc. As the Representative of the Several underwriters, if any, named in Schedule I hereto 640 Fifth Avenue, 4th Floor New Yor

Certificate of Amendment of Second Amended and Restated Certificate of Incorporation (filed as Exhibit 3.1 on Form 8-K on June 25, 2025)

Exhibit 3.1 AMENDMENT TO SECOND AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF CELLECTAR BIOSCIENCES, INC. Cellectar Biosciences, Inc., (the “Corporation”), a corporation organized and existing under and by virtue of the General Corporation Law of the State of Delaware, hereby certifies as follows: 1. This Certificate of Amendment amends the provisions of the Corporation’s Second Amended and

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 24, 2025 Cellectar Bioscienc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 24, 2025 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

Cellectar Biosciences Announces One-for-Thirty Reverse Stock Split

Exhibit 99.1 Cellectar Biosciences Announces One-for-Thirty Reverse Stock Split FLORHAM PARK, N.J., June 18, 2025 - Cellectar Biosciences, Inc. (Nasdaq: CLRB), a late-stage clinical biopharmaceutical company focused on the discovery and development of drugs for the treatment of cancer, today announced a one-for-thirty reverse stock split (the “Reverse Stock Split”) of the company’s common stock, p

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 18, 2025 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 13, 2025 Cellectar Bioscienc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 13, 2025 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

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. 1)

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. 1) Filed by the Registrant x Filed by a Party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e) (2)) ¨ Def

Regulation FD Disclosure, Entry into a Material Definitive Agreement, Material Modification to Rights of Security Holders, Unregistered Sales of Equity Securities, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 5, 2025 Cellectar Biosciences, Inc.

Inducement Letter in consideration for Exercise of the Common Stock Purchase Warrants issued on June 5, 2020, October 25, 2022 and July 21, 2024 (filed as Exhibit 10.1 on Form 8-K on June 5, 2025)

Exhibit 10.1 CELLECTAR BIOSCIENCES, INC. June 5, 2025 Holder of Common Stock Purchase Warrants issued on June 5, 2020, October 25, 2022 and July 21, 2024 Re: Inducement Offer to Exercise Common Stock Purchase Warrants Dear Holder: Cellectar Biosciences, Inc. (the “Company”) is pleased to offer to you the opportunity to reduce the exercise price of (i) the Common Stock Purchase Warrants to purchase

Cellectar Biosciences Enters into Common Stock Agreements to Raise $2.5 Million Priced at Market Under Nasdaq Rules

Exhibit 99.1 Cellectar Biosciences Enters into Common Stock Agreements to Raise $2.5 Million Priced at Market Under Nasdaq Rules FLORHAM PARK, N.J., June 5, 2025 - Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage clinical biopharmaceutical company focused on the discovery and development of drugs for the treatment of cancer, today announced the entry into definitive agreements to raise $2.

LETTER

May 29, 2025 James Caruso Chief Executive Officer Cellectar Biosciences, Inc. 100 Campus Drive Florham Park, NJ 07932 Re: Cellectar Biosciences, Inc. Draft Registration Statement on Form S-1 Submitted May 23, 2025 CIK No. 0001279704 Dear James Caruso: This is to advise you that we do not intend to review your registration statement. We request that you publicly file your registration statement at

CONFIDENTIAL TREATMENT REQUESTED BY CELLECTAR BIOSCIENCES, INC. PURSUANT TO 17 C.F.R. SECTION 200.83 As confidentially submitted to the Securities and Exchange Commission on May 23, 2025. This draft registration statement has not been publicly filed

CONFIDENTIAL TREATMENT REQUESTED BY CELLECTAR BIOSCIENCES, INC. PURSUANT TO 17 C.F.R. SECTION 200.83 As confidentially submitted to the Securities and Exchange Commission on May 23, 2025. This draft registration statement has not been publicly filed with the Securities and Exchange Commission and all information herein remains strictly confidential. Registration No. 333- UNITED STATES SECURITIES A

Cellectar Biosciences Reports First Quarter 2025 Financial Results and Provides a Corporate Update Company Seeking Conditional Approval from European Medicines Agency (EMA) for Iopofosine I 131 in Waldenstrom Macroglobulinemia based upon CLOVER WaM P

Exhibit 99.1 Cellectar Biosciences Reports First Quarter 2025 Financial Results and Provides a Corporate Update Company Seeking Conditional Approval from European Medicines Agency (EMA) for Iopofosine I 131 in Waldenstrom Macroglobulinemia based upon CLOVER WaM Phase 2 Study Data CLOVER WaM Major Response Rate for BTKi-Treated Patients 59.0% Company to hold webcast and conference call at 8:30 AM E

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q [mark one] ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: March 31, 2025 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-36598 CELLE

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 13, 2025 Cellectar Bioscience

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 13, 2025 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): April 30, 2025 Cellectar Bioscien

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): April 30, 2025 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commissio

Cellectar Announces Plan to Explore Strategic Alternatives

Exhibit 99.1 Cellectar Announces Plan to Explore Strategic Alternatives Florham Park, N.J., April 30, 2025 (GLOBE NEWSWIRE) - Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage clinical biopharmaceutical company focused on the discovery, development and commercialization of drugs for the treatment of cancer, today announced that the company will explore a full range of strategic alternatives

ARS

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended: December 31, 2024 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission File Number 001-36598 CELLECTA

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

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 Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Definitive Proxy State

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

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 Filed by the Registrant x Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Definitive Proxy State

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

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 Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy State

Amended and Restated By-Laws of Cellectar Biosciences, Inc., effective as of March 11, 2025

Exhibit 3.1 AMENDED AND RESTATED BY-LAWS OF Cellectar Biosciences, Inc. a Delaware corporation Article I STOCKHOLDERS Section 1.1. Annual Meetings. An annual meeting of stockholders to elect directors and transact such other business as may properly be presented to the meeting may be held at such place, within or without the State of Delaware as may be designated by or in the manner provided in th

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): March 11, 2025 Cellectar Bioscien

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): March 11, 2025 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commissio

List of Subsidiaries (filed as Exhibit 21.1 on Form 10-K on March 13, 2025)

EXHIBIT 21.1 CELLECTAR BIOSCIENCES, INC. LIST OF SUBSIDIARIES Set forth below is a list of the subsidiaries of Cellectar Biosciences, Inc. as of December 31, 2024: Subsidiary Name Jurisdiction of Organization Cellectar, Inc. Wisconsin

Cellectar Biosciences Reports Financial Results for Year Ended 2024 and Provides a Corporate Update Achieves alignment with U.S. Food and Drug Administration (FDA) on regulatory path for potential accelerated approval of iopofosine I 131 as a treatme

Exhibit 99.1 Cellectar Biosciences Reports Financial Results for Year Ended 2024 and Provides a Corporate Update Achieves alignment with U.S. Food and Drug Administration (FDA) on regulatory path for potential accelerated approval of iopofosine I 131 as a treatment for Waldenström macroglobulinemia (WM) Evaluating timing for Phase 1 solid tumor studies; Auger-emitting radioconjugate prepared for P

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended: December 31, 2024 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission File Number 001-36598 CELLECTA

Insider Trading Policy

Exhibit 19.1 Cellectar Biosciences, Inc. Insider Trading Policy (as amended and restated on September 24, 2018) Introduction This Insider Trading Policy sets forth the rules of Cellectar Biosciences, Inc. (“Cellectar” or the “Company”) relating to the purchase and sale of the Company’s securities by all full and part-time employees, officers and directors of Cellectar and related persons. The Comp

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): March 13, 2025 Cellectar Bioscien

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): March 13, 2025 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commissio

PROSPECTUS Up to 19,221,348 Shares of Common Stock Offered by the Selling Stockholders CELLECTAR BIOSCIENCES, INC. Common Stock

Table of Contents Filed Pursuant to Rule 424(b)(3) Registration No. 333-284580 PROSPECTUS Up to 19,221,348 Shares of Common Stock Offered by the Selling Stockholders CELLECTAR BIOSCIENCES, INC. Common Stock This prospectus relates to the resale, from time to time by the selling stockholders named in this prospectus (the “selling stockholders”), of up to 19,221,348 shares of our common stock (the “

CELLECTAR BIOSCIENCES, INC. 100 Campus Drive Florham Park, New Jersey 07932

CELLECTAR BIOSCIENCES, INC. 100 Campus Drive Florham Park, New Jersey 07932 February 4, 2025 VIA EDGAR Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Attention: Joshua Gorsky Re: Cellectar Biosciences, Inc. Registration Statement on Form S-1 Filed January 29, 2025 File No. 333-284580 Ladies and Gentlemen: Pursuant to Rule 461(a) under t

NYC#: 139632.2

EX-99.A BD-DIR-RESOL 2 rosalindclrbexa.htm NYC#: 139632.2 Exhibit A Joint Filing Agreement The undersigned hereby agree that this Statement on Schedule 13G/A with respect to the beneficial ownership of shares of Common Stock of Cellectar Biosciences, Inc. is filed jointly, on behalf of each of them. Rosalind Advisors, Inc. By: Name: Steven Salamon Title: President Rosalind Master Fund L.P. By: Nam

LETTER

February 3, 2025 James V. Caruso Chief Executive Officer Cellectar Biosciences, Inc. 100 Campus Drive Florham Park, NJ 07932 Re: Cellectar Biosciences, Inc. Registration Statement on Form S-1 Filed January 29, 2025 File No. 333-284580 Dear James V. Caruso: This is to advise you that we have not reviewed and will not review your registration statement. Please refer to Rules 460 and 461 regarding re

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): January 30, 2025 Cellectar Biosci

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): January 30, 2025 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commiss

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Cellectar Biosciences, Inc.

As filed with the Securities and Exchange Commission on January 29, 2025

Table of Contents As filed with the Securities and Exchange Commission on January 29, 2025 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): January 12, 2025 Cellectar Biosci

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): January 12, 2025 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commiss

Cellectar Biosciences to Highlight 2025 Strategic Initiatives at Upcoming Biotech Showcase during the JP Morgan Healthcare Conference Oral Presentation Presented at ASH 2024 Showed Iopofosine I 131 Achieved an 83.6% ORR and Exceeded Primary and Secon

Exhibit 99.1 Cellectar Biosciences to Highlight 2025 Strategic Initiatives at Upcoming Biotech Showcase during the JP Morgan Healthcare Conference Oral Presentation Presented at ASH 2024 Showed Iopofosine I 131 Achieved an 83.6% ORR and Exceeded Primary and Secondary Efficacy Endpoints in Phase 2 CLOVER-WaM Study for Relapsed/Refractory Waldenstrom’s Macroglobulinemia Plans to Advance Iopofosine I

Evaluating strategic options for iopofosine I 131 a late-stage clinical program with compelling Phase 2 data and a substantial market opportunity Focusing on advancing radiotherapeutic assets including alpha- and Auger-emitting radioconjugates into P

Exhibit 99.1 December 10, 2024 Cellectar Biosciences Provides Strategic Update on Clinical Development, Pipeline Programs and Corporate Restructuring Evaluating strategic options for iopofosine I 131 a late-stage clinical program with compelling Phase 2 data and a substantial market opportunity Focusing on advancing radiotherapeutic assets including alpha- and Auger-emitting radioconjugates into P

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): December 10, 2024 Cellectar Biosc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): December 10, 2024 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commis

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 18, 2024 Cellectar Biosc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 18, 2024 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commis

Cellectar Biosciences Reports Financial Results for Q3 2024 and Provides a Corporate Update Phase 2 CLOVER-WaM pivotal study data selected for oral presentation at 66th Annual American Society of Hematology Meeting and Exposition Raised approximately

Exhibit 99.1 Cellectar Biosciences Reports Financial Results for Q3 2024 and Provides a Corporate Update Phase 2 CLOVER-WaM pivotal study data selected for oral presentation at 66th Annual American Society of Hematology Meeting and Exposition Raised approximately $19.4 million with potential to raise up to an additional $73.3 million Company to hold webcast and conference call at 8:30 AM ET today

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q [mark one] ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: September 30, 2024 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-36598 C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 15, 2024 Cellectar Biosc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 15, 2024 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commis

CLRB / Cellectar Biosciences, Inc. / ADAR1 Capital Management, LLC - SC 13G/A Passive Investment

SC 13G/A 1 tm2428381d5sc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* Cellectar Biosciences, Inc. (Name of Issuer) Common Stock, par value $0.00001 per share (Title of Class of Securities) 15117F500 (CUSIP Number) September 30, 2024 (Date of Event which Requires Filing of this Stat

CLRB / Cellectar Biosciences, Inc. / LYTTON LAURENCE W Passive Investment

SC 13G/A 1 clrb13ga2.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 2)* Cellectar Biosciences, Inc. (Name of Issuer) Common Stock, par value $0.00001 (Title of Class of Securities) 15117F807 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of this Statement) Check the appropriat

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 12b-25 NOTIFICATION OF LATE FILING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 12b-25 NOTIFICATION OF LATE FILING (Check one):  ¨ Form 10-K  ¨ Form 20-F  ¨ Form 11-K  x Form 10-Q ¨ Form 10-D  ¨ Form N-CEN  ¨ Form N-CSR For Period Ended: September 30, 2024 ¨ Transition Report on Form 10-K ¨ Transition Report on Form 20-F ¨ Transition Report on Form 11-K ¨ Transition Report on Form 10-Q For the Transition Period Ended:   Nothing in this form shall be construed to imply that the Commission has verified any information contained herein.

Cellectar Biosciences Announces Compliance Regarding Filing of Form 10-Q

Exhibit 99.1 Cellectar Biosciences Announces Compliance Regarding Filing of Form 10-Q FLORHAM PARK, N.J., Nov 1, 2024 (GLOBE NEWSWIRE) - Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage clinical biopharmaceutical company, announced today it received a letter dated October 31, 2024, from Nasdaq, Inc. informing the Company that it had regained compliance with Nasdaq Listing Rule 5250(c)(1).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 1, 2024 Cellectar Biosci

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 1, 2024 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commiss

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q [mark one] ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: June 30, 2024 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-36598 CELLEC

List of Subsidiaries

EXHIBIT 21.1 CELLECTAR BIOSCIENCES, INC. LIST OF SUBSIDIARIES Set forth below is a list of the subsidiaries of Cellectar Biosciences, Inc. as of December 31, 2023: Subsidiary Name Jurisdiction of Organization Cellectar, Inc. Wisconsin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A Amendment No. 2

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A Amendment No. 2 ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended: December 31, 2023 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission File Number

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q/A (Amendment No. 1)

Table of Contents U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q/A (Amendment No. 1) [mark one] ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: March 31, 2024 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File

Cellectar to Restate Previously Issued Financial Statements – Company Announces Receipt of Expected Delinquency Notification Letter from Nasdaq

Exhibit 99.1 Cellectar to Restate Previously Issued Financial Statements – Company Announces Receipt of Expected Delinquency Notification Letter from Nasdaq FLORHAM PARK, N.J., August 23, 2024 – Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage clinical biopharmaceutical company focused on the discovery, development, and commercialization of drugs for the treatment of cancer, today announce

Regulation FD Disclosure, Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 20, 2024 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commissi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 12b-25 NOTIFICATION OF LATE FILING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 12b-25 NOTIFICATION OF LATE FILING (Check one):  ¨ Form 10-K  ¨ Form 20-F  ¨ Form 11-K  x Form 10-Q ¨ Form 10-D  ¨ Form N-CEN  ¨ Form N-CSR For Period Ended: June 30, 2024 ¨ Transition Report on Form 10-K ¨ Transition Report on Form 20-F ¨ Transition Report on Form 11-K ¨ Transition Report on Form 10-Q For the Transition Period Ended:   Nothing in this form shall be construed to imply that the Commission has verified any information contained herein.

NYC#: 139632.2

Schedule 13G NYC#: 139632.2 Exhibit A Joint Filing Agreement The undersigned hereby agree that this Statement on Schedule 13G/A with respect to the beneficial ownership of shares of Common Stock of Cellectar Biosciences, Inc. is filed jointly, on behalf of each of them. Rosalind Advisors, Inc. By: Name: Steven Salamon Title: President Rosalind Master Fund L.P. By: Name: Mike McDonald Title: Direct

CLRB / Cellectar Biosciences, Inc. / Rosalind Advisors, Inc. Passive Investment

Schedule 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A (Amendment No. 7) Under the Securities Exchange Act of 1934 Cellectar Biosciences, Inc. (Name of Issuer) Common Shares (Title of Class of Securities) 15117F500 (CUSIP Number) July 25, 2024 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuan

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 13, 2024 Cellectar Bioscie

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 13, 2024 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commissi

Cellectar Biosciences Reports Financial Results for Q2 2024 and Provides a Corporate Update Management to host a conference call today at 8:30 am ET

Exhibit 99.1 Cellectar Biosciences Reports Financial Results for Q2 2024 and Provides a Corporate Update Management to host a conference call today at 8:30 am ET FLORHAM PARK, N.J., August 13, 2024 – Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage clinical biopharmaceutical company focused on the discovery, development, and commercialization of drugs for the treatment of cancer, today ann

Non-Reliance on Previously Issued Financial Statements or a Related Audit Report or Completed Interim Review

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 9, 2024 Cellectar Biosciences, Inc.

Cellectar Biosciences’ Iopofosine I 131 Exceeds Primary Endpoint in Waldenstrom’s Macroglobulinemia Pivotal Study with 78% of Major Response Patients Remaining Progression Free at 18 Months 80% Overall Response Rate Achieved

Exhibit 99.1 Cellectar Biosciences’ Iopofosine I 131 Exceeds Primary Endpoint in Waldenstrom’s Macroglobulinemia Pivotal Study with 78% of Major Response Patients Remaining Progression Free at 18 Months 80% Overall Response Rate Achieved · 56.4% major response rate exceeded 20% primary endpoint · 98.2% disease control rate achieved in heavily pretreated patients · Responses shown in difficult-to-t

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 23, 2024 Cellectar Biosciences

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 23, 2024 Cellectar Biosciences, Inc.

Inducement Letter in consideration for Exercise of the Tranche B warrants (filed as Exhibit 10.1 on Form 8-K on July 22, 2024)

Exhibit 10.1 July 21, 2024 [Name] [Address] Re: Reprice and Reload Offer of Common Stock Purchase Warrants To Whom It May Concern: Cellectar Biosciences, Inc. (the “Company”) is pleased to offer to you the opportunity to receive new Common Stock purchase warrants of the Company in consideration for the exercise in full of the Tranche B warrants issued to you on or about September 8, 2023 (the “Exi

Form of Common Stock Purchase Warrant C (filed as Exhibit 4.3 on Form 8-K on July 22, 2024)

Exhibit 4.3 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

Cellectar Biosciences Announces Exercise of Tranche B Warrants and Purchase of New Warrants for Approximately $19.4 million with the Potential to Raise Up to an Additional $73.3 Million

Exhibit 99.1 Cellectar Biosciences Announces Exercise of Tranche B Warrants and Purchase of New Warrants for Approximately $19.4 million with the Potential to Raise Up to an Additional $73.3 Million FLORHAM PARK, N.J., July 22, 2024 - Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage clinical biopharmaceutical company focused on the discovery, development and commercialization of drugs for

Form of Common Stock Purchase Warrant B (filed as Exhibit 4.2 on Form 8-K on July 22, 2024)

Exhibit 4.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

CELLECTAR BIOSCIENCES, INC. 100 Campus Drive Florham Park, New Jersey 07932

CELLECTAR BIOSCIENCES, INC. 100 Campus Drive Florham Park, New Jersey 07932 July 22, 2024 Via EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549-3720 Attention: Mr. Tim Buchmiller Re: Acceleration Request for Cellectar Biosciences, Inc. Registration Statement on Form S-3 (File No. 333-279731) Ladies and Gentlemen: Pursuant to Rul

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 21, 2024 Cellectar Biosciences

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 21, 2024 Cellectar Biosciences, Inc.

Form of Common Stock Purchase Warrant A (filed as Exhibit 4.1 on Form 8-K on July 22, 2024)

Exhibit 4.1 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

CLRB / Cellectar Biosciences, Inc. / Rosalind Advisors, Inc. Passive Investment

Schedule 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A (Amendment No. 6) Under the Securities Exchange Act of 1934 Cellectar Biosciences, Inc. (Name of Issuer) Common Shares (Title of Class of Securities) 15117F500 (CUSIP Number) June 28, 2024 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuan

NYC#: 139632.2

EX-99.A BD-DIR-RESOL 2 rosalindclrbexa.htm NYC#: 139632.2 Exhibit A Joint Filing Agreement The undersigned hereby agree that this Statement on Schedule 13G/A with respect to the beneficial ownership of shares of Common Stock of Cellectar Biosciences, Inc. is filed jointly, on behalf of each of them. Rosalind Advisors, Inc. By: Name: Steven Salamon Title: President Rosalind Master Fund L.P. By: Nam

Financial Statements and Exhibits, Changes in Registrant's Certifying Accountant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): July 8, 2024 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

Letter Regarding Change in Certifying Accountant (filed as Exhibit 16.1 on Form 8-K on July 11, 2024)

Exhibit 16.1 Baker Tilly US, LLP 4807 Innovate Ln. PO Box 7398 Madison, WI 53707-7398 United States of America T: +1 (608) 249 6622 F: +1 (608) 249 8532 bakertilly.com July 11, 2024 Securities and Exchange Commission 100 F Street, NE Washington, DC 20549 Dear Ladies and Gentlemen: We are the former independent registered public accounting firm for Cellectar Biosciences, Inc. (the “Company”). We ha

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 20, 2024 Cellectar Biosciences

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 20, 2024 Cellectar Biosciences, Inc.

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 14, 2024 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

2021 Stock Incentive Plan, as Amended (filed as Exhibit 10.1 on Form 8-K on June 14, 2024)

Exhibit 10.1 CELLECTAR BIOSCIENCES, INC. 2021 STOCK INCENTIVE PLAN, AS AMENDED SECTION 1. General Purpose of the Plan; Definitions The purpose of this 2021 Stock Incentive Plan (the “Plan”) is to encourage and enable officers and employees of, and other persons providing services to, Cellectar Biosciences, Inc. (the “Company”) and its Subsidiaries (as defined below) to acquire a proprietary intere

LETTER

United States securities and exchange commission logo May 31, 2024 James V. Caruso President and Chief Executive Officer Cellectar Biosciences, Inc. 100 Campus Drive Florham Park, New Jersey 07932 Re: Cellectar Biosciences, Inc. Registration Statement on Form S-3 Filed May 24, 2024 File No. 333-279731 Dear James V. Caruso: This is to advise you that we have not reviewed and will not review your re

Equity Distribution Agreement, dated May 24, 2024, between the Company and Piper Sandler & Co. (filed as Exhibit 1.2 on Form S-3 on May 24, 2024)

Exhibit 1.2 CELLECTAR BIOSCIENCES, INC. EQUITY DISTRIBUTION AGREEMENT May 24, 2024 PIPER SANDLER & CO. U.S. Bancorp Center 800 Nicollet Mall Minneapolis, Minnesota 55402 Ladies and Gentlemen: As further set forth in this agreement (this “Agreement”), Cellectar Bioscience, Inc., a company organized under the laws of Delaware (the “Company”), proposes to issue and sell from time to time through Pipe

Calculation of Registration Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Cellectar Biosciences, Inc.

As filed with the Securities and Exchange Commission on May 24, 2024.

As filed with the Securities and Exchange Commission on May 24, 2024. Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-3 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 CELLECTAR BIOSCIENCES, INC. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation or organization) 04-3321804 (I.R.

Form of Indenture (filed as Exhibit 4.7 on Form S-3 on May 24, 2024)

Exhibit 4.7 CELLECTAR BIOSCIENCES, INC. INDENTURE Dated as of , 20 [ ] Trustee TABLE OF CONTENTS Page ARTICLE I. DEFINITIONS AND INCORPORATION BY REFERENCE 1 Section 1.1. Definitions. 1 Section 1.2. Other Definitions. 3 Section 1.3. Incorporation by Reference of Trust Indenture Act. 4 Section 1.4. Rules of Construction. 4 ARTICLE II. THE SECURITIES 4 Section 2.1. Issuable in Series. 4 Section 2.2.

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

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 Filed by the Registrantx Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) x Definitive Proxy Statem

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 14, 2024 Cellectar Bioscience

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 14, 2024 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q [mark one] ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: March 31, 2024 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-36598 CELLE

Cellectar Biosciences Reports Financial Results for Q1 2024 and Provides a Corporate Update Management to host a conference call today at 8:30 am ET WM pivotal study data to be announced in June

Exhibit 99.1 Cellectar Biosciences Reports Financial Results for Q1 2024 and Provides a Corporate Update Management to host a conference call today at 8:30 am ET WM pivotal study data to be announced in June FLORHAM PARK, N.J., May 14, 2024 – Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage clinical biopharmaceutical company focused on the discovery, development, and commercialization of d

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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

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 Filed by the Registrant x Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Definitive Proxy State

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

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 Filed by the Registrant x Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) x Definitive Proxy State

NYC#: 139632.2

EX-99.A BD-DIR-RESOL 2 rosalindclrbexa.htm CLRB EXA NYC#: 139632.2 Exhibit A Joint Filing Agreement The undersigned hereby agree that this Statement on Schedule 13G/A with respect to the beneficial ownership of shares of Common Stock of Cellectar Biosciences, Inc. is filed jointly, on behalf of each of them. Rosalind Advisors, Inc. By: Name: Steven Salamon Title: President Rosalind Master Fund L.P

CLRB / Cellectar Biosciences, Inc. / Rosalind Advisors, Inc. - CLRB 13GA05 Passive Investment

SC 13G/A 1 rosalindclrb13ga5apr24.htm CLRB 13GA05 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A (Amendment No. 5) Under the Securities Exchange Act of 1934 Cellectar Biosciences, Inc. (Name of Issuer) Common Shares (Title of Class of Securities) 15117F500 (CUSIP Number) March 31, 2024 (Date of Event which Requires Filing of this Statement) Check the appropr

Clawback Policy

Exhibit 97 CELLECTAR BIOSCIENCES, INC. POLICY ON RECOUPMENT OF INCENTIVE COMPENSATION Introduction The Board of Directors (the “Board”) of Cellectar Biosciences, Inc. (the “Company”) has adopted this Policy on Recoupment of Incentive Compensation (this “Policy”), which provides for the recoupment of compensation in certain circumstances in the event of a restatement of financial results by the Com

Exhibit 4.3 to Amendment No. 1 to our Annual Report on Form 10-K filed on April 1, 2024

EXHIBIT 4.3 DESCRIPTION OF SECURITIES REGISTERED UNDER SECTION 12(B) OF THE SECURITIES EXCHANGE ACT OF 1934 The following summary description of our common stock is based on the provisions of our Second Amended and Restated Certificate of Incorporation, as amended, which we refer to as our certificate of incorporation or charter, our by-laws, and the applicable provisions of the Delaware General C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A Amendment No. 1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A Amendment No. 1 x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 ¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 001-36598 CELLECTAR B

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): March 27, 2024 Cellectar Bioscien

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): March 27, 2024 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commissio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended: December 31, 2023 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission File Number 001-36598 CELLECTA

List of Subsidiaries

EXHIBIT 21.1 CELLECTAR BIOSCIENCES, INC. LIST OF SUBSIDIARIES Set forth below is a list of the subsidiaries of Cellectar Biosciences, Inc. as of December 31, 2023: Subsidiary Name Jurisdiction of Organization Cellectar, Inc. Wisconsin

Cellectar Biosciences Reports Financial Results for Year Ended 2023 and Provides a Corporate Update Management to host a conference call today at 8:30 am ET

Exhibit 99.1 Cellectar Biosciences Reports Financial Results for Year Ended 2023 and Provides a Corporate Update Management to host a conference call today at 8:30 am ET FLORHAM PARK, N.J., Mar. 27, 2024 – Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage clinical biopharmaceutical company focused on the discovery, development, and commercialization of drugs for the treatment of cancer, tod

CLRB / Cellectar Biosciences, Inc. / Rosalind Advisors, Inc. Passive Investment

Schedule 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A (Amendment No. 4) Under the Securities Exchange Act of 1934 Cellectar Biosciences, Inc. (Name of Issuer) Common Shares (Title of Class of Securities) 15117F500 (CUSIP Number) December 31, 2023 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate the rule pur

US15117F8077 / Cellectar Biosciences Inc / Nantahala Capital Management, LLC - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* CELLECTAR BIOSCIENCES, INC. (Name of Issuer) Common stock, par value $0.00001 (Title of Class of Securities) 15117F807 (CUSIP Number) December 31, 2023 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate the rule

CLRB / Cellectar Biosciences, Inc. / Lincoln Park Capital Fund, LLC - SC 13G/A Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* CELLECTAR BIOSCIENCES, INC. (Name of Issuer) COMMON STOCK, $0.00001 PAR VALUE (Title of Class of Securities) 15117F500 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the r

Joint Filing Agreement

EX-99.1 2 tm246286d2ex1.htm EXHIBIT 1 EXHIBIT 1 Joint Filing Agreement The undersigned hereby agree that they are filing this statement jointly pursuant to Rule 13d-1(k)(1). Each of them is responsible for the timely filing of such Schedule 13G, and for the completeness and accuracy of the information concerning such person contained therein; but none of them is responsible for the completeness or

NYC#: 139632.2

EX-99.A BD-DIR-RESOL 2 rosalindclrbexa.htm NYC#: 139632.2 Exhibit A Joint Filing Agreement The undersigned hereby agree that this Statement on Schedule 13G/A with respect to the beneficial ownership of shares of Common Stock of Cellectar Biosciences, Inc. is filed jointly, on behalf of each of them. Rosalind Advisors, Inc. By: Name: Steven Salamon Title: President Rosalind Master Fund L.P. By: Nam

US15117F8077 / Cellectar Biosciences Inc / LYTTON LAURENCE W Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* Cellectar Biosciences, Inc. (Name of Issuer) Common Stock, par value $0.00001 (Title of Class of Securities) 15117F807 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rul

US15117F8077 / Cellectar Biosciences Inc / HIRSCHMAN ORIN Passive Investment

SC 13G/A 1 formsc13ga.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Amendment No. 1 Under the Securities Exchange Act of 1934 CELLECTAR BIOSCIENCES INC (Name of Issuer) Common Stock, $0.00001 par value (Title of Class of Securities) 15117F807 (CUSIP Number) January 23, 2024 (Date of Event Which Requires Filing of this Statement) Check the appropriate bo

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): February 2, 2024 Cellectar Biosci

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): February 2, 2024 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commiss

US15117F8077 / Cellectar Biosciences Inc / ADAR1 Partners, LP - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Cellectar Biosciences, Inc. (Name of Issuer) Common Stock, par value $0.00001 per share (Title of Class of Securities) 15117F807 (CUSIP Number) January 23, 2024 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): January 25, 2024 Cellectar Biosci

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): January 25, 2024 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commiss

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): January 8, 2024 Cellectar Bioscie

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): January 8, 2024 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commissi

Cellectar Biosciences Announces Positive Topline Data Achieving Primary Endpoint in Pivotal Clinical Study of Iopofosine I 131 in Waldenstrom’s Macroglobulinemia

Exhibit 99.1 Cellectar Biosciences Announces Positive Topline Data Achieving Primary Endpoint in Pivotal Clinical Study of Iopofosine I 131 in Waldenstrom’s Macroglobulinemia · Iopofosine tested in heavily pretreated multi-class refractory population with a median of four prior therapies and achieves 75.6% Overall Response Rate; 61% Major Response Rate (95% CI, 44.5%, 75.8%); 100% Disease Control

US15117F8077 / Cellectar Biosciences Inc / LYTTON LAURENCE W Passive Investment

SC 13G 1 cellbio13g.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Cellectar Biosciences, Inc. (Name of Issuer) Common Stock, par value $0.00001 (Title of Class of Securities) 15117F807 (CUSIP Number) October 25, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate bo

US15117F8077 / Cellectar Biosciences Inc / HIRSCHMAN ORIN Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 CELLECTAR BIOSCIENCES INC (Name of Issuer) Common Stock, $0.00001 par value (Title of Class of Securities) 15117F807 (CUSIP Number) November 7, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which th

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 21, 2023 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commis

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q [mark one] ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: September 30, 2023 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-36598 C

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 2, 2023 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commiss

Cellectar to Release Top-line Data from WM Pivotal Trial During the JP Morgan Healthcare Conference the Week of January 8, 2024 Reports Preliminary Financial Results for Third Quarter 2023 and Provides a Corporate Update Conference Call scheduled for

Exhibit 99.1 Cellectar to Release Top-line Data from WM Pivotal Trial During the JP Morgan Healthcare Conference the Week of January 8, 2024 Reports Preliminary Financial Results for Third Quarter 2023 and Provides a Corporate Update Conference Call scheduled for today at 8:30 am Eastern Time FLORHAM PARK, N.J., Nov. 2, 2023 - Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage clinical bioph

PROSPECTUS Up to 34,487,159 Shares of Common Stock Offered by the Selling Stockholders CELLECTAR BIOSCIENCES, INC. Common Stock

Filed Pursuant to Rule 424(b)(3) Registration No. 333-274880 PROSPECTUS Up to 34,487,159 Shares of Common Stock Offered by the Selling Stockholders CELLECTAR BIOSCIENCES, INC. Common Stock This prospectus relates to the resale, from time to time by the selling stockholders named in this prospectus (the “selling stockholders”) of up to 34,487,159 shares of our common stock (the “Shares”), which con

Certificate of Amendment to Second Amended and Restated Certificate of Incorporation (filed as Exhibit 3.1 on Form 8-K on October 27, 2023)

Exhibit 3.1 AMENDMENT TO SECOND AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF CELLECTAR BIOSCIENCES, INC. Cellectar Biosciences, Inc., (the “Corporation”), a corporation organized and existing under and by virtue of the General Corporation Law of the State of Delaware, hereby certifies as follows: 1. This Certificate of Amendment amends the provisions of the Corporation’s Second Amended and

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): October 25, 2023 CELLECTAR BIOSCI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): October 25, 2023 CELLECTAR BIOSCIENCES, INC. (Exact name of registrant as specified in its charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commiss

CELLECTAR BIOSCIENCES, INC. 100 Campus Drive Florham Park, New Jersey 07932

CELLECTAR BIOSCIENCES, INC. 100 Campus Drive Florham Park, New Jersey 07932 October 26, 2023 Via EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549-3720 Attention: Ms. Cindy Polynice Re: Acceleration Request for Cellectar Biosciences, Inc. Registration Statement on Form S-3 (File No. 333-274880) Ladies and Gentlemen: Pursuant to

As filed with the Securities and Exchange Commission on October 25, 2023.

As filed with the Securities and Exchange Commission on October 25, 2023. Registration No. 333-274880 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Amendment No. 1 to FORM S-3 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 CELLECTAR BIOSCIENCES, INC. (Exact name of registrant as specified in its charter) Delaware 2834 04-3321804 (State or other jurisdiction of in

LETTER

United States securities and exchange commission logo October 12, 2023 James Caruso President and Chief Executive Officer Cellectar Biosciences, Inc.

As filed with the Securities and Exchange Commission on October 5, 2023.

As filed with the Securities and Exchange Commission on October 5, 2023. Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-3 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 CELLECTAR BIOSCIENCES, INC. (Exact name of registrant as specified in its charter) Delaware 2834 04-3321804 (State or other jurisdiction of incorporation or organizatio

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Cellectar Biosciences, Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant x Filed by a Party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant x Filed by a Party other than the Registrant ¨ Check the appropriate box: x Preliminary Proxy Statement ¨ Confidential, for Use of

Certificate of Elimination of the Series A Convertible Preferred Stock, the Series B Convertible Preferred Stock and the Series C Convertible Preferred Stock (filed as Exhibit 3.1 on Form 8-K on September 8, 2023)

Exhibit 3.1 CERTIFICATE OF ELIMINATION OF CELLECTAR BIOSCIENCES, INC. (Pursuant to Section 151 of the Delaware General Corporation Law) Pursuant to the provisions of Section 151(g) of the General Corporation Law of the State of Delaware, CELLECTAR BIOSCIENCES, Inc., a corporation organized and existing under the laws of the State of Delaware (the “Company”), hereby certifies as follows: FIRST: Tha

Certificate of Designation of Preferences, Rights and Limitations of the Series E Convertible Voting Preferred Stock (filed as Exhibit 3.3 on Form 8-K on September 8, 2023)

Exhibit 3.3 Cellectar Biosciences, Inc. CERTIFICATE OF DESIGNATION OF PREFERENCES, RIGHTS AND LIMITATIONS OF SERIES E CONVERTIBLE VOTING PREFERRED STOCK PURSUANT TO SECTION 151 OF THE DELAWARE GENERAL CORPORATION LAW Cellectar Biosciences, Inc., a Delaware corporation (the “Corporation”), in accordance with the provisions of Section 103 of the Delaware General Corporation Law (the “DGCL”) does her

Form of Securities Purchase Agreement (filed as Exhibit 10.1 on Form 8-K on September 8, 2023)

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this “Agreement”) is dated as of September 5, 2023, by and among Cellectar Biosciences, Inc., a Delaware corporation (the “Company”), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a “Purchaser” and collectively, the “Purchasers”). RECITALS A. The Company and eac

Form of Tranche B Warrant (filed as Exhibit 4.2 on Form 8-K on September 8, 2023)

Exhibit 4.2 NEITHER THESE SECURITIES NOR THE SECURITIES ISSUABLE UPON CONVERSION OR EXERCISE OF THESE SECURITIES HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES AND THE SECURITIES ISSUABLE UPON CONVERSION OR EXERCISE OF THESE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): September 5, 2023 Cellectar Biosc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): September 5, 2023 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commis

Amendment No. 1 to Certificate of Designation of the Series D Preferred Stock (filed as Exhibit 3.2 on Form 8-K on September 8, 2023)

Exhibit 3.2 AMENDMENT NO. I TO CERTIFICATE OF DESIGNATION of SERIES D CONVERTIBLE PREFERRED STOCK of CELLECTAR BIOSCIENCES, INC. (Pursuant to Section 151 of the Delaware General Corporate Law) Cellectar Biosciences, Inc. (the “Corporation”), a corporation organized and existing under the General Corporation Law of the State of Delaware (“DGCL”), hereby certifies that the following resolution was a

Form of Tranche A Warrant (filed as Exhibit 4.1 on Form 8-K on September 8, 2023)

Exhibit 4.1 NEITHER THESE SECURITIES NOR THE SECURITIES ISSUABLE UPON CONVERSION OR EXERCISE OF THESE SECURITIES HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES AND THE SECURITIES ISSUABLE UPON CONVERSION OR EXERCISE OF THESE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 16, 2023 Cellectar Bioscie

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 16, 2023 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commissi

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 14, 2023 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commissi

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q [mark one] ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: June 30, 2023 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-36598 CELLEC

Cellectar Reports Financial Results for Second Quarter 2023 and Provides a Corporate Update

Exhibit 99.1 Cellectar Reports Financial Results for Second Quarter 2023 and Provides a Corporate Update FLORHAM PARK, N.J., August 14, 2023 - Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage biopharmaceutical company focused on the discovery, development and commercialization of targeted treatments for cancer, today announced financial results for the second quarter ended June 30, 2023 an

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 23, 2023 Cellectar Bioscienc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 23, 2023 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 28, 2023 Cellectar Bioscienc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 28, 2023 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

2021 Stock Incentive Plan, as Amended (filed as Exhibit 10.1 on Form 8-K on June 29, 2023)

Exhibit 10.1 Appendix A Cellectar Biosciences, Inc. 2021 STOCK INCENTIVE PLAN, AS AMENDED SECTION 1. General Purpose of the Plan; Definitions The purpose of this 2021 Stock Incentive Plan (the “Plan”) is to encourage and enable officers and employees of, and other persons providing services to, Cellectar Biosciences, Inc. (the “Company”) and its Subsidiaries (as defined below) to acquire a proprie

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

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 Filed by the Registrant x Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Definitive Proxy State

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 14, 2023

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 14, 2023 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorp

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 14, 2023 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

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

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 Filed by the Registrant x Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Definitive Proxy State

Cellectar Provides a Research and Development Program Summary Waldenstrom’s macroglobulinemia pivotal trial topline data now expected second half of 2023; pediatric high grade glioma trial to initiate in Q3 Phospholipid drug conjugate platform valida

Exhibit 99.1 Cellectar Provides a Research and Development Program Summary Waldenstrom’s macroglobulinemia pivotal trial topline data now expected second half of 2023; pediatric high grade glioma trial to initiate in Q3 Phospholipid drug conjugate platform validation with alpha emitting radioisotopes, small molecules, peptides and oligos FLORHAM PARK, N.J., June 12, 2023 - Cellectar Biosciences, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 12, 2023 Cellectar Bioscienc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): June 12, 2023 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): May 4, 2023 Cellectar Biosciences, Inc. (Exact name of registrant as specified in its charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission F

Cellectar Reports Financial Results for First Quarter 2023 and Provides a Corporate Update

Exhibit 99.1 Cellectar Reports Financial Results for First Quarter 2023 and Provides a Corporate Update FLORHAM PARK, N.J., May 4, 2023 - Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage biopharmaceutical company focused on the discovery, development and commercialization of targeted treatments for cancer, today announced financial results for the first quarter ended March 31, 2023 and pro

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q [mark one] ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: March 31, 2023 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-36598 CELLE

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant x Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of

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

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 Filed by the Registrant x Filed by a party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) x Definitive Proxy State

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A Amendment No. 1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A Amendment No. 1 x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 ¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 333-119366 CELLECTAR

Cellectar Reports Financial Results for Year Ended 2022 and Provides a Corporate Update

Exhibit 99.1 Cellectar Reports Financial Results for Year Ended 2022 and Provides a Corporate Update FLORHAM PARK, N.J., Mar. 9, 2023 - Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage biopharmaceutical company focused on the discovery, development and commercialization of targeted treatments for cancer, today announced financial results for the year ended December 31, 2022 and provided a

Form of First Amendment of Lease, dated December 30, 2022

Exhibit 10.26 1 FIRST AMENDMENT OF LEASE THIS FIRST AMENDMENT OF LEASE (the “Amendment”), made as of December 30, 2022, between CAMPUS 100 LLC, a New Jersey limited liability company, having an office at c/o Opal Holdings, LLC, 1140 Avenue of the Americas, Suite PH, New York, New York 10036 (the “Landlord”), and CELLECTAR BIOSCIENCES, INC., a Delaware corporation, having an address at 100 Campus D

Power of Attorney (included on the Signatures page of this Annual Report on Form 10-K)

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended: December 31, 2022 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission File Number 333-119366 CELLECT

Description of Securities Registered under Section 12(b) of the Securities Exchange Act of 1934

EXHIBIT 4.3 DESCRIPTION OF SECURITIES REGISTERED UNDER SECTION 12(B) OF THE SECURITIES EXCHANGE ACT OF 1934 The following summary description of our common stock is based on the provisions of our Second Amended and Restated Certificate of Incorporation, as amended, which we refer to as our certificate of incorporation or charter, our by-laws, and the applicable provisions of the Delaware General C

List of Subsidiaries

EXHIBIT 21.1 CELLECTAR BIOSCIENCES, INC. LIST OF SUBSIDIARIES Set forth below is a list of the subsidiaries of Cellectar Biosciences, Inc. as of December 31, 2022: Subsidiary Name Jurisdiction of Organization Cellectar, Inc. Wisconsin

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): March 9, 2023 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commission

Joint Filing Agreement

Exhibit A Joint Filing Agreement The undersigned hereby agree that this Statement on Schedule 13G with respect to the beneficial ownership of shares of Common Stock of Mediwound Ltd.

CLRB / Cellectar Biosciences Inc / Rosalind Advisors, Inc. - CELLECTAR SC 13G/A Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A (Amendment No. 3) Under the Securities Exchange Act of 1934 Cellectar Biosciences, Inc. (Name of Issuer) Common Shares (Title of Class of Securities) 15117F500 (CUSIP Number) December 31, 2022 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to whic

CLRB / Cellectar Biosciences Inc / LYTTON LAURENCE W Passive Investment

SC 13G/A 1 cellectar13ga3.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 3)* Cellectar Biosciences, Inc. (Name of Issuer) Common Stock, par value $0.00001 (Title of Class of Securities) 15117F500 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Check the approp

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 30, 2022 Cellectar Bioscie

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 30, 2022 Cellectar Biosciences, Inc.

7,027,043 SHARES OF COMMON STOCK ISSUABLE UPON EXERCISE OF OUTSTANDING WARRANTS

Filed Pursuant to Rule 424(b)(3) Registration No. 333-268554 PROSPECTUS 7,027,043 SHARES OF COMMON STOCK ISSUABLE UPON EXERCISE OF OUTSTANDING WARRANTS We are not selling any shares of our common stock under this prospectus and will not receive any proceeds from the sale of shares by the selling stockholders. This prospectus relates to the resale of up to 7,027,043 shares of our common stock, par

Amended and Restated By-laws

Exhibit 3.1 AMENDED AND RESTATED BY-LAWS OF Cellectar Biosciences, Inc. a Delaware corporation Article I STOCKHOLDERS Section 1.1. Annual Meetings. An annual meeting of stockholders to elect directors and transact such other business as may properly be presented to the meeting may be held at such place, within or without the State of Delaware as may be designated by or in the manner provided in th

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Entry into a Material Definitive Agreement, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 29, 2022 Cellectar Biosciences, Inc.

Form of Indemnification Agreement

Exhibit 10.1 PRIVILEGED AND CONFIDENTIAL DIRECTOR AND OFFICER INDEMNIFICATION AGREEMENT THIS INDEMNIFICATION AGREEMENT (this ?Agreement?) is entered into as of the day of , 20, by and between Cellectar Biosciences, Inc., a Delaware corporation (the ?Company?), and (?Indemnitee?). RECITALS A. The Company is aware that competent and experienced persons are increasingly reluctant to serve or continue

CELLECTAR BIOSCIENCES, INC. 100 Campus Drive Florham Park, New Jersey 07932

CORRESP 1 filename1.htm CELLECTAR BIOSCIENCES, INC. 100 Campus Drive Florham Park, New Jersey 07932 November 30, 2022 VIA EDGAR Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Attention: Jason Drory Re: Cellectar Biosciences, Inc. Registration Statement on Form S-1 Filed November 23, 2022 File No. 333-268554 Ladies and Gentlemen: Pursuan

LETTER

United States securities and exchange commission logo November 29, 2022 James Caruso President and Chief Executive Officer Cellectar Biosciences, Inc.

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables FORM S-1 (Form Type) Cellectar Biosciences, Inc.

As filed with the Securities and Exchange Commission on November 23, 2022

As filed with the Securities and Exchange Commission on November 23, 2022 Registration No.

List of Subsidiaries

EXHIBIT 21.1 CELLECTAR BIOSCIENCES, INC. LIST OF SUBSIDIARIES Set forth below is a list of the subsidiaries of Cellectar Biosciences, Inc.: Subsidiary Name Jurisdiction of Organization Cellectar, Inc. Wisconsin

Joint Filing Agreement

Exhibit A Joint Filing Agreement The undersigned hereby agree that this Statement on Schedule 13G/A with respect to the beneficial ownership of shares of Common Stock of Delcath Systems, Inc.

CLRB / Cellectar Biosciences Inc / Rosalind Advisors, Inc. - CELLECTAR SC 13 G/A 2 Passive Investment

SC 13G/A 1 Cellectar13GA211-02-22.htm CELLECTAR SC 13 G/A 2 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A (Amendment No. 2) Under the Securities Exchange Act of 1934 Cellectar Biosciences, Inc. (Name of Issuer) Common Shares (Title of Class of Securities) 15117F500 (CUSIP Number) October 25, 2022 (Date of Event which Requires Filing of this Statement) Check

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents ? ? ? U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q [mark one] ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: September 30, 2022 ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-3

Cellectar Reports Financial Results for Third Quarter 2022 and Provides a Corporate Update

Exhibit 99.1 Cellectar Reports Financial Results for Third Quarter 2022 and Provides a Corporate Update FLORHAM PARK, N.J., November 3, 2022 - Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage biopharmaceutical company focused on the discovery, development and commercialization of targeted treatments for cancer, today announced financial results for the third quarter ended September 30, 202

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): November 3, 2022 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commiss

Form of Pre-Funded Warrant

Exhibit 4.2 EXHIBIT A-2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE ?SECURITIES ACT?), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFEC

Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): October 20, 2022 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commiss

Form of Hybrid Securities Purchase Agreement, dated as of October 20, 2022, by and between the Company and the purchasers named therein

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this ?Agreement?) is dated as of October 20, 2022, between Cellectar Biosciences, Inc., a Delaware corporation (the ?Company?), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a ?Purchaser? and collectively, the ?Purchasers?). WHEREAS, subject to the terms and con

Form of Common Warrant

Exhibit 4.1 EXHIBIT A-1 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE ?SECURITIES ACT?), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFEC

Form of PIPE Securities Purchase Agreement, dated as of October 20, 2022, by and between the Company and the purchasers named therein

Exhibit 10.2 PRIVATE PLACEMENT SECURITIES PURCHASE AGREEMENT This Securities Purchase Agreement (this ?Agreement?) is dated as of October 20, 2022, between Cellectar Biosciences, Inc., a Delaware corporation (the ?Company?), and each purchaser identified on the signature pages hereto (each, including its successors and assigns, a ?Purchaser? and collectively, the ?Purchasers?). WHEREAS, subject to

Cellectar Biosciences Announces Closing of Concurrent Registered Direct and Private Placement Offerings of Approximately $10.7 Million Priced At-The-Market Under Nasdaq Rules

Exhibit 99.2 October 25, 2022 Cellectar Biosciences Announces Closing of Concurrent Registered Direct and Private Placement Offerings of Approximately $10.7 Million Priced At-The-Market Under Nasdaq Rules FLORHAM PARK, N.J., Oct. 25, 2022 (GLOBE NEWSWIRE) - Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage clinical biopharmaceutical company focused on the discovery, development and commerci

Joint Filing Agreement

EXHIBIT 1 Joint Filing Agreement The undersigned hereby agree that they are filing this statement jointly pursuant to Rule 13d-1(k)(1).

Cellectar Biosciences Announces Concurrent Registered Direct and Private Placement Offerings of Approximately $10.7 Million Priced At-The-Market Under Nasdaq Rules

Exhibit 99.1 October 21, 2022 Cellectar Biosciences Announces Concurrent Registered Direct and Private Placement Offerings of Approximately $10.7 Million Priced At-The-Market Under Nasdaq Rules FLORHAM PARK, N.J., Oct. 21, 2022 (GLOBE NEWSWIRE) - Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage clinical biopharmaceutical company focused on the discovery, development and commercialization o

Form of Registration Rights Agreement, dated as of October 20, 2022, by and between the Company and the purchasers named therein

Exhibit 10.3 REGISTRATION RIGHTS AGREEMENT This Registration Rights Agreement (this ?Agreement?) is made and entered into as of October 20, 2022, between Cellectar Biosciences, Inc., a Delaware corporation (the ?Company?), and each of the several purchasers signatory hereto (each such purchaser, a ?Purchaser? and, collectively, the ?Purchasers?). This Agreement is made pursuant to the Purchase Agr

Placement Agency Agreement, dated as of October 20, 2022, by and between Cellectar Biosciences, Inc. and Oppenheimer & Co. Inc. (filed as Exhibit 1.1 on Form 8-K on October 25, 2022)

Exhibit 1.1 PLACEMENT AGENCY AGREEMENT October 20, 2022 Oppenheimer & Co. Inc. 85 Broad Street New York, New York 10004 Ladies and Gentlemen: Introduction. Subject to the terms and conditions herein (this ?Agreement?), Cellectar Biosciences, Inc., a Delaware corporation (the ?Company?), hereby agrees to sell up to an aggregate of $10,740,020.57 of registered and unregistered securities (the ?Secur

CLRB / Cellectar Biosciences Inc / Lincoln Park Capital Fund, LLC - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* CELLECTAR BIOSCIENCES, INC. (Name of Issuer) COMMON STOCK, $0.00001 PAR VALUE (Title of Class of Securities) 15117F500 (CUSIP Number) October 21, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule

CELLECTAR BIOSCIENCES, INC. 3,275,153 Shares of Common Stock

Prospectus Supplement Filed pursuant to Rule 424(b)(5) (to Prospectus dated August 20, 2020) Registration No.

CELLECTAR BIOSCIENCES, INC. Common Stock

SUPPLEMENT NO. 1 DATED OCTOBER 20, 2022 TO PROSPECTUS SUPPLEMENT DATED AUGUST 20, 2020 Filed pursuant to Rule 424(b)(5) (to Prospectus dated August 20, 2020) Registration No. 333-244362 CELLECTAR BIOSCIENCES, INC. Common Stock This Supplement No. 1 to Prospectus Supplement (this “Supplement”) supplements and amends the Prospectus Supplement dated August 20, 2020 (the “Prospectus Supplement”). This

Regulation FD Disclosure, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): September 22, 2022 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commi

Cellectar Awarded $2 Million Grant to Expand Its Ongoing Phase 1 Study of Iopofosine I 131 in Pediatric Brain Tumors

Exhibit 99.1 Cellectar Awarded $2 Million Grant to Expand Its Ongoing Phase 1 Study of Iopofosine I 131 in Pediatric Brain Tumors FLORHAM PARK, N.J., September 22, 2022 - Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage biopharmaceutical company focused on the discovery, development and commercialization of targeted treatments for cancer, today announced it has been awarded $1.98 million i

Cellectar Announces Publication of Data from Its Expansion Cohort of the Phase II CLOVER-1 Study Iopofosine I-131 in Relapsed/Refractory Multiple Myeloma in Nature’s Blood Cancer Journal Initial data show ORR of 50% in Quad-Class Refractory Multiple

EX-99.1 2 tm2225694d1ex99-1.htm EXHIBIT 99.1 Exhibit 99.1 Cellectar Announces Publication of Data from Its Expansion Cohort of the Phase II CLOVER-1 Study Iopofosine I-131 in Relapsed/Refractory Multiple Myeloma in Nature’s Blood Cancer Journal Initial data show ORR of 50% in Quad-Class Refractory Multiple Myeloma Patients Who Have Failed anti-BCMA Immunotherapy with Median of Nine Lines of Prior

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): September 13, 2022 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commi

U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents ? ? ? U.S. SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q [mark one] ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended: June 30, 2022 ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 1-36598

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 5, 2022 Cellectar Biosciences, Inc. (Exact name of Registrant as Specified in its Charter) Delaware 1-36598 04-3321804 (State or other jurisdiction of incorporation) (Commissio

As filed with the Securities and Exchange Commission on August 5, 2022

As filed with the Securities and Exchange Commission on August 5, 2022 Registration No.

Cellectar Reports Financial Results for Second Quarter 2022

Exhibit 99.1 Cellectar Reports Financial Results for Second Quarter 2022 FLORHAM PARK, N.J., August 5, 2022 - Cellectar Biosciences, Inc. (NASDAQ: CLRB), a late-stage biopharmaceutical company focused on the discovery, development and commercialization of targeted treatments for cancer, today announced financial results for the second quarter ended June 30, 2022. ?During the second quarter, ipofos