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Form 8-K

sec.gov
ONCO The article is a Form 8-K filing detailing an additional advance of $500,000 to Realbotix, LLC. This is a routine financial disclosure and does not inherently indicate positive or negative performance.

8-K — Onconetix, Inc.

Accession: 0001213900-26-111944

Filed: 2026-10-23

Period: 2026-10-22

CIK: 0001782107

SIC: 2834 (PHARMACEUTICAL PREPARATIONS)

Item: Other Events

Item: Financial Statements and Exhibits

Documents

8-K — ea0309517-8k_onconetix.htm (Primary)

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8-K — CURRENT REPORT

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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 22, 2026

Onconetix,

Inc.

(Exact

Name of Registrant as Specified in its Charter)

Delaware

001-41294

83-2262816

(State or other Jurisdiction

of Incorporation)

(Commission File Number)

(I.R.S. Employer

Identification No.)

201

E. Fifth Street, Suite 1900, Cincinnati, Ohio

45202

(Address of Principal Executive

Offices)

(Zip Code)

Registrant’s

telephone number, including area code: (513) 620-4101

(Former

name or former address, if changed since last report.)

Check

the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under

any of the following provisions:

☐

Written communications

pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☒

Soliciting material pursuant

to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐

Pre-commencement communications

pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐

Pre-commencement communications

pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities

registered pursuant to Section 12(b) of the Act:

Title

of Each Class

Trading

Symbol(s)

Name

of Each Exchange on Which Registered

Common Stock, par value

$0.00001 per share

ONCO

The Nasdaq Stock Market

LLC

Indicate

by check mark whether the registrant is an emerging growth company as defined in in Rule 405 of the Securities Act of 1933 (§230.405

of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging

growth company ☒

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 13(a) of the Exchange Act. ☐

Item

8.01. Other Events.

On

October 22, 2026, Onconetix, Inc. (the “Company”) made an additional advance of $500,000 to Realbotix, LLC (“Realbotix”)

pursuant to that certain Grid Promissory Note, dated September 11, 2026 (the “Note”), previously disclosed in the Company’s

Current Report on Form 8-K filed with the Securities and Exchange Commission on September 14, 2026 (the “Prior Form 8-K”).

As

previously disclosed, pursuant to the Note, the Company agreed to make available to Realbotix loans in an aggregate principal amount

of up to $5.0 million, of which $2.5 million was advanced on September 11, 2026. Following the additional $500,000 advance, the aggregate

principal amount outstanding under the Note is $3.0 million.

The

terms of the Note remain unchanged. The description of the Note contained in the Prior Form 8-K is incorporated herein by reference.

Item

9.01. Exhibits.

Exhibit

No.

Description

104

Cover Page Interactive

Data File (embedded within the Inline XBRL document).

1

SIGNATURE

Pursuant

to the requirements of the Securities Exchange Act of 1934, the registrant has caused this report to be signed on its behalf by the undersigned

hereunto duly authorized.

Onconetix, Inc.

Dated: October 23, 2026

By:

/s/

David A. White

David A. White

Chief Executive Officer

2

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