---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-23-123002"
form_type: "8-K"
ticker: null
cik: "0001745020"
company_name: "Theseus Pharmaceuticals, Inc."
filed_at: "2023-12-04T23:59:59+00:00"
generated_at: "2026-06-07T18:48:44.367698+00:00"
event_type: "leadership"
sentiment: "negative"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# Theseus Pharma terminates CEO and CMO; appoints CFO Dahms as President

## Summary
- CEO Timothy Clackson and CMO David Kerstein terminated without cause effective Dec 7, 2023 as part of workforce reduction.
- Clackson receives $0.9M severance plus 18-month equity vesting; Kerstein receives $0.6M plus 12-month equity vesting.
- CFO Bradford Dahms appointed President and director; salary increased to $500K; eligible for retention bonus of 1.5x salary.
- Dahms retention bonus paid in two installments; requires employment through earlier of strategic transaction or Feb 28, 2024.
- Both departing executives entered consulting agreements through Mar 31, 2024.

## SEC filing metadata
- accession: 0001104659-23-123002
- form_type: 8-K
- cik: 0001745020
- company_name: Theseus Pharmaceuticals, Inc.
- filed_at: 2023-12-04T23:59:59+00:00
- event_type: leadership
- sentiment: negative
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 5.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1745020/000110465923123002/0001104659-23-123002-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1745020/000110465923123002/tm2332045d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-23-123002
- JSON: https://secwatch.observer/filing/0001104659-23-123002.json
- Plain text: https://secwatch.observer/filing/0001104659-23-123002.txt

## Key facts
- Executive change
  Timothy P. Clackson was terminated as President and Chief Executive Officer at Theseus Pharmaceuticals, Inc..
  - Action: terminated
  - Role: President and Chief Executive Officer
  source text: the Company terminated the employment of Timothy P. Clackson, Ph.D. as President and Chief Executive Officer of the Company, effective as of December 7, 2023
  evidence_url: https://www.sec.gov/Archives/edgar/data/1745020/000110465923123002/0001104659-23-123002-index.htm
- Executive change
  David Kerstein was terminated as Chief Medical Officer at Theseus Pharmaceuticals, Inc..
  - Action: terminated
  - Role: Chief Medical Officer
  source text: the Company also terminated the employment of David Kerstein, M.D. as the Chief Medical Officer of the Company, effective as of the Separation Date
  evidence_url: https://www.sec.gov/Archives/edgar/data/1745020/000110465923123002/0001104659-23-123002-index.htm

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