Cellectar Biosciences Inc

S-11 tm2516057d3_s1.htm FORM S-1

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

Registration No. 333-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-1

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

CELLECTAR BIOSCIENCES, INC.

(Exact name of registrant as specified in its charter)

100 Campus Drive, Florham Park, New Jersey 07932

Telephone (608) 441-8120

(Address, including zip code and telephone number, including area code, of registrant’s principal executive offices)

James V. Caruso**

President and Chief Executive Officer

Cellectar Biosciences, Inc.

100 Campus Drive, Florham Park, New Jersey 07932

Telephone (608) 441-8120

(Name, address, including zip code and telephone number, including area code, of agent for service)

With copies to:

Approximate date of commencement of proposed sale to the public:

As soon as practicable after this Registration Statement becomes effective.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box. x

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.¨

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.¨

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.¨

The registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until the Registration Statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

The information in this preliminary prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell these securities and is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

**Subject to Completion

Dated June 26, 2025

Preliminary Prospectus

**Up to 755,667 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

Or

**Up to 755,667 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 Warrant to purchase one (1) Share of Common Stock

Up to 45,340 Representative Warrants to Purchase up to 45,340 Shares of Common Stock

**Up to 1,556,674 Shares of Common Stock Issuable Upon Exercise of up to (i) 755,667 Pre-Funded Warrants, (ii) up to 755,667

Common Warrants and (iii) up to 45,340 Representative Warrants

We are offering up to 755,667 Class A Units (the “Class A Units”) with each Class A Unit consisting of (i) one (1) share of our common stock, par value $0.00001 per share (the “common stock”) and (ii) one (1) warrant to purchase one (1) share of common stock (each, a “Common Warrant”) at an assumed public offering price of $7.94 per Class A Unit (which is the last reported sale price of our common stock on The Nasdaq Capital Market on June 25, 2025).

We are also offering to certain purchasers whose purchase of Class A Units in this offering would otherwise result in the purchaser, together with its affiliates and certain related parties, beneficially owning more than 4.99% (or, at the election of the purchaser, 9.99%) of our outstanding common stock immediately following the consummation of this offering, the opportunity to purchase, if any such purchaser so chooses, up to 755,667 Class B Units (the “Class B Units”), with each Class B Unit consisting of (i) one (1) pre-funded warrant (each, a “Pre-Funded Warrant”) to purchase one (1) share of common stock, in lieu of shares of common stock and (ii) one (1) Common Warrant. The purchase price of each Class B Unit will be equal to the public offering price for Class A Units in this offering, minus $0.00001. Each Pre-Funded Warrant is exercisable for one (1) share of our common stock and has an exercise price of $0.00001 per share, and a perpetual term. For each Class B Unit that we sell, the number of Class A Units we are offering will be reduced on a one-for-one basis. This prospectus also relates to the offering of common stock issuable upon exercise of the Pre-Funded Warrants and Common Warrants. We collectively refer to the Class A Units, Class B Units, the shares of common stock, Pre-Funded Warrants, Common Warrants and the shares of common stock underlying the Pre-Funded Warrants and Common Warrants as the “securities.”

The Class A Units and Class B Units will not be certificated and the shares of common stock, Pre-Funded Warrants, and Common Warrants are immediately separable and will be issued separately in this offering. Each Common Warrant will be exercisable immediately upon issuance, have a term of five (5) years from the date of issuance and an exercise price equal to $ .

The underwriters have the option to purchase up to 113,350 additional shares of common stock and/or additional Common Warrants to purchase up to an additional 113,350 shares of common stock solely to cover over-allotments, if any, at the public offering price, less the underwriting discounts and commissions. The over-allotment option may be used to purchase shares of common stock and/or Common Warrants, or any combination thereof, as determined by the underwriters. The overallotment option is exercisable for forty-five days from the date of this prospectus.

Our common stock is listed on The Nasdaq Capital Market under the symbol “CLRB”. On June 25, 2025, the last reported sale price of our common stock was $7.94 per share. The assumed public offering price may not be indicative of the final public offering price. The final public offering price will be determined through negotiation between us and the underwriters based upon a number of factors, including our history and our prospects, the industry in which we operate, our past and present operating results and the general condition of the securities markets at the time of this offering and may be at a discount to the current market price.

On June 24, 2025, a reverse stock split of our outstanding shares of common stock took effect at a ratio of one-for-thirty (the “Reverse Stock Split”), which was approved by our Board of Directors and majority of stockholders, and consummated pursuant to a Certificate of Amendment filed with the Secretary of State of Delaware on June 23, 2025. There will be no change to the number of authorized shares or the par value per share. Unless the context expressly dictates otherwise, all references to share and per share amounts referred to in this prospectus give effect to the Reverse Stock Split. However, our periodic and current reports that are incorporated by reference, and all other documents that were filed prior to June 24, 2025, do not give effect to the Reverse Stock Split.

Investing in our securities involves a high degree of risk. Before making an investment decision, please read the information under “Risk Factors” beginning on page 17 of this prospectus and under similar headings in any amendment or supplement to this prospectus or in any filing with the Securities and Exchange Commission that is incorporated by reference herein.

(1) The public offering price and underwriting discount corresponds to (i) a public offering price per Class A Unit of $ ($ net of the underwriting discount) and (ii) a public offering price per Class B Unit of $ ($ net of the underwriting discount).

(2) We have agreed to reimburse the representative of the underwriters for certain expenses and issue the representative, or its designees, warrants to purchase up to 6.0% of the number of Class A Units and Class B Units sold in this offering, including shares of common stock sold pursuant to the over-allotment option, if any. See “Underwriting” on page 56 for additional information regarding underwriting compensation.

(3) The above summary of offering proceeds does not give effect to any proceeds from the cash exercise of any Pre-Funded Warrants, Common Warrants, or representative warrants being issued in this offering.

The underwriters expect to deliver the securities to purchasers in the offering on or about , 2025.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

Ladenburg Thalmann

The date of this prospectus is , 2025.

Table of Contents

The registration statement we filed with the Securities and Exchange Commission, or the SEC, includes exhibits that provide more detail of the matters discussed in this prospectus. You should read this prospectus, the related exhibits filed with the SEC, and the documents incorporated by reference herein before making your investment decision. You should rely only on the information provided in this prospectus and the documents incorporated by reference herein or any amendment thereto. In addition, this prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the heading “Where You Can Find Additional Information.” Information contained in later-dated documents incorporated by reference will automatically supplement, modify or supersede, as applicable, the information contained in this prospectus or in earlier-dated documents incorporated by reference.

We have not authorized anyone to provide any information or to make any representations other than those contained in this prospectus, the documents incorporated by reference herein or in any free writing prospectuses prepared by or on behalf of us or to which we have referred you. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. The information contained in this prospectus, the documents incorporated by reference herein or in any applicable free writing prospectus is current only as of its date, regardless of its time of delivery or any sale of our securities. Our business, financial condition, results of operations and prospects may have changed since that date.

This prospectus is an offer to sell only the securities offered hereby, and only under circumstances and in jurisdictions where it is lawful to do so. We are not, and the underwriters are not, making an offer to sell these securities in any state or jurisdiction where the offer or sale is not permitted.

The terms “Cellectar Biosciences,” “Cellectar,” the “Company,” “our,” “us” and “we,” as used in this prospectus, refer to Cellectar Biosciences, Inc., a Delaware corporation, and its subsidiaries unless we state otherwise or the context indicates otherwise.