---
schema_version: "secwatch.filing_event.v1"
accession: "0001213900-23-097738"
form_type: "8-K"
ticker: "ONCO"
cik: "0001782107"
company_name: "Onconetix, Inc."
filed_at: "2023-12-21T23:59:59+00:00"
generated_at: "2026-06-07T09:16:24.414725+00:00"
event_type: "m_and_a"
sentiment: "neutral"
materiality_score: 1.0
calibrated_materiality_score: 1.0
confidence: "high"
source: SEC EDGAR
---

# Onconetix acquires Proteomedix AG in $75M share exchange; pre-closing holders diluted to 5.4%

## Summary
- Exchange consideration: 4,083,779 common shares plus 2,692,633 Series B convertible preferred (convertible into 269,263,300 common).
- Post-closing ownership: Sellers 79.8%, new Investor 5.9%, pre-closing Onconetix stockholders 5.4%.
- Series B convertible preferred auto-converts on stockholder approval; cash settlement if approval not obtained by Jan 1, 2025.
- Lock-up on Exchange Shares and Conversion Shares for 6 months after stockholder approval.
- Post-approval board: 5 directors – 3 designated by Proteomedix, 2 by Onconetix.

## SEC filing metadata
- accession: 0001213900-23-097738
- form_type: 8-K
- ticker: ONCO
- cik: 0001782107
- company_name: Onconetix, Inc.
- filed_at: 2023-12-21T23:59:59+00:00
- event_type: m_and_a
- sentiment: neutral
- materiality_score: 1.0
- calibrated_materiality_score: 1.0
- confidence: high
- sec_items: 1.01, 3.02, 5.02, 5.03, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1782107/000121390023097738/0001213900-23-097738-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1782107/000121390023097738/ea190395-8k_onconetix.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001213900-23-097738
- JSON: https://secwatch.observer/filing/0001213900-23-097738.json
- Plain text: https://secwatch.observer/filing/0001213900-23-097738.txt

## Key facts
- Executive change
  Christian Brühlmann was appointed as Chief Strategy Officer at Onconetix, Inc..
  - Action: appointed
  - Role: Chief Strategy Officer
  source text: On December 15, 2023, Onconetix appointed Christian Brühlmann, 47, as Chief Strategy Officer of Onconetix, effective immediately
  evidence_url: https://www.sec.gov/Archives/edgar/data/1782107/000121390023097738/0001213900-23-097738-index.htm
- Executive change
  Ralph Schiess was appointed as Chief Science Officer at Onconetix, Inc..
  - Action: appointed
  - Role: Chief Science Officer
  source text: On December 15, 2023, Onconetix appointed Ralph Schiess, 45, as Chief Science Officer of Onconetix, effective immediately
  evidence_url: https://www.sec.gov/Archives/edgar/data/1782107/000121390023097738/0001213900-23-097738-index.htm
- Governance Changes
  Onconetix, Inc.: Amended bylaws to reflect the name change to Onconetix, Inc (effective 2023-12-15).
  - Change: bylaw amendment
  - Effective: 2023-12-15
  source text: On December 1, 2023, the Board approved the Name Change and an amendment to the Company’s bylaws to reflect the Name Change, effective as of the Closing Date on December 15, 2023. No other changes were made to the bylaws.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1782107/000121390023097738/0001213900-23-097738-index.htm
- Governance Changes
  Onconetix, Inc.: Amended articles of incorporation to change company name from Blue Water Biotech, Inc. to Onconetix, Inc (effective 2023-12-15).
  - Change: charter amendment
  - Effective: 2023-12-15
  source text: On December 15, 2023, Onconetix filed a Certificate of Amendment to its Amended and Restated Articles of Incorporation with the Delaware Secretary of State (the “ Amendment ”). The Amendment changed the name of Onconetix from “Blue Water Biotech, Inc.” to “Onconetix, Inc.,” effective immediately (the “ Name Change ”).
  evidence_url: https://www.sec.gov/Archives/edgar/data/1782107/000121390023097738/0001213900-23-097738-index.htm
- Material Agreements
  Onconetix, Inc. entered into Share Exchange Agreement with Proteomedix AG, the Sellers, and the Sellers’ Representative valued at $75,000,000 (effective 2023-12-15).
  - Action: entry
  - Agreement: merger
  - Counterparty: Proteomedix AG, the Sellers, and the Sellers’ Representative
  - Value: $75,000,000
  - Effective: 2023-12-15
  source text: On December 15, 2023, Onconetix, Inc, a Delaware corporation f/k/a Blue Water Biotech, Inc. (“ Onconetix ” or the “ Buyer ”), entered into a Share Exchange Agreement (the “ Share Exchange Agreement ”), by and among (i) Onconetix, (ii) Proteomedix AG, a Swiss Company (“ Proteomedix ” or the “ Company ”), (iii) each of the holders of outstanding capital stock or Company Convertible Securities (other than Company Stock Options) named therein (collectively, the “ Sellers ”) and (iv) Thomas Meier, in the capacity as the representative of Sellers in accordance with the terms and conditions of the Share Exchange Agreement (the “ Sellers’ Representative ”).
  evidence_url: https://www.sec.gov/Archives/edgar/data/1782107/000121390023097738/0001213900-23-097738-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.