Onconetix Provides Strategic Bridge Financing to Realbotix LLC in Support of Pending Acquisition (Form 8-K)

Onconetix Provides Strategic Bridge Financing to Realbotix LLC in Support of Pending Acquisition

Initial Advance of $2.5 Million to Realbotix LLC to Support Growth and Working Capital; Non-Interest Bearing Facility Is Automatically Cancelled and Discharged in Full Upon Closing of Pending Acquisition

CINCINNATI, Ohio - September 14, 2026, 2026 - Onconetix, Inc. (Nasdaq: ONCO) ("Onconetix" or the "Company") today announced that it has provided a strategic bridge financing facility of up to $5,000,000 to Realbotix LLC ("Realbotix"), the target of its previously announced pending acquisition, to support Realbotix's growth and working capital needs while the parties advance toward closing of the acquisition. The financing was provided in connection with the Share Exchange Agreement between the two companies, announced on February 12, 2026.

The facility provides for an aggregate principal amount of up to $5,000,000, with an initial advance of $2,500,000.

The facility is non-interest bearing prior to the closing of the Share Exchange Agreement. Upon closing of the acquisition, the facility and all obligations thereunder will be automatically cancelled and discharged in full. In addition, the cash required at closing of the acquisitions will be reduced by the total principal advanced under the facility plus an additional $500,000. If the Share Exchange Agreement is terminated, interest accrues at 12% per annum from the date of termination. A description of the Note is included in Onconetix's Current Report on Form 8-K filed with the SEC on September 14, 2026. The full text of the Note is filed as an exhibit to that report and is available at www.sec.gov.

As previously announced on February 12, 2026, Onconetix entered into the Share Exchange Agreement to acquire 100% of the issued and outstanding equity interests of Realbotix LLC in an all-stock transaction. The combined company is expected to trade on Nasdaq following closing, which is subject to Onconetix shareholder approval, required regulatory approvals, and other closing conditions.

This communication is being provided for informational purposes only. Investors are cautioned not to place undue reliance on forward-looking or projected information.

About Onconetix, Inc.

Onconetix, Inc. (Nasdaq: ONCO) is a commercial-stage biotechnology company focused on the research, development, and commercialization of innovative oncology solutions. Onconetix owns Proclarix®, an in vitro diagnostic test for prostate cancer originally developed by Proteomedix and approved for sale in the European Union under the IVDR, which it anticipates will be marketed in the U.S. as a lab developed test through its license agreement with Labcorp. For more information, visit www.onconetix.com.

About Realbotix LLC

Realbotix LLC is a wholly-owned subsidiary of Realbotix Corp. (TSX-V: XBOT; Frankfurt: 76M0.F; OTC: XBOTF) and the target of Onconetix's pending acquisition. Realbotix LLC develops AI-powered humanoid robots designed for human interaction across enterprise and consumer environments. Manufactured in the United States, Realbotix's patented AI and robotics technologies enable lifelike expressions, motion, vision, and social engagement. For more information, visit www.realbotix.ai.

Additional Information and Where to Find It

In connection with the proposed transaction between Realbotix and Onconetix, Onconetix intends to file with the SEC a Registration Statement on Form S-4 (the "Registration Statement") to register the common stock to be issued by Onconetix in connection with the proposed transaction. The Registration Statement will include a proxy statement of Onconetix and a prospectus of Onconetix (the "Proxy Statement/Prospectus"), and each of Realbotix and Onconetix may file with the SEC other relevant documents concerning the proposed transaction. After the Registration Statement is declared effective, the definitive Proxy Statement/Prospectus will be sent to the stockholders of Onconetix to seek their approval of the proposed transaction. This is not a substitute for the Registration Statement, the Proxy Statement/Prospectus or any other relevant documents that Realbotix or Onconetix has filed or will file with the SEC. BEFORE MAKING ANY VOTING OR INVESTMENT DECISION, INVESTORS AND STOCKHOLDERS OF ONCONETIX ARE URGED TO CAREFULLY AND ENTIRELY READ THE REGISTRATION STATEMENT AND PROXY STATEMENT/PROSPECTUS REGARDING THE PROPOSED TRANSACTION AND ANY OTHER RELEVANT DOCUMENTS, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THOSE DOCUMENTS, IF AND WHEN THEY BECOME AVAILABLE, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT REALBOTIX, ONCONETIX, THE PROPOSED TRANSACTION, AND RELATED MATTERS.

A copy of the Registration Statement, Proxy Statement/Prospectus, as well as other relevant documents filed by Realbotix and Onconetix with the SEC, may be obtained free of charge, when they become available, at the SEC's website at www.sec.gov. The information on Realbotix or Onconetix's respective websites is not, and shall not be deemed to be, a part of this communication or incorporated into other filings either company makes with the SEC.

Participants in the Solicitation

Realbotix, Onconetix and certain of their respective directors, executive officers, and employees may be deemed to be participants in the solicitation of proxies in connection with the proposed transaction. Information about the directors and executive officers of Onconetix, their ownership of Onconetix common stock, and Onconetix's transactions with related persons is set forth in the 10-K, as filed with the SEC on March 13, 2026, and other documents that may be filed from time to time with the SEC. Additional information about the directors and executive officers of Realbotix and Onconetix and other persons who may be deemed to be participants in the solicitation of stockholders of Onconetix in connection with the proposed transaction and a description of their direct and indirect interests will be included in the Proxy Statement/Prospectus related to the proposed transaction or other relevant materials, which will be filed with the SEC. These documents may be obtained free of charge, when they become available, at the SEC's website at www.sec.gov and from Onconetix using the sources indicated above.

No Offer or Solicitation

This communication is for informational purposes only and is not intended to and does not constitute an offer to sell or the solicitation of an offer to buy or sell any securities or the solicitation of any proxy, vote or approval, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act, or in a transaction exempt from the registration requirements of the Securities Act.