---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-24-209907"
form_type: "8-K"
ticker: "KPTI"
cik: "0001503802"
company_name: "Karyopharm Therapeutics Inc."
filed_at: "2024-08-29T23:59:59+00:00"
generated_at: "2026-05-31T06:58:35.148237+00:00"
event_type: "leadership"
sentiment: "negative"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Karyopharm CFO Michael Mason to resign Nov 5; transition agreement signed

## Summary
- Michael Mason, EVP/CFO/Treasurer, notified resignation effective November 5, 2024; will serve until then.
- Company initiated search for a successor CFO.
- Transition agreement provides $100,000 lump sum payable on Nov 6, 2024, if employed through resignation.
- Mason to enter consulting agreement through March 1, 2025, with continued vesting of equity awards.
- Consulting fee: hourly pay after 5th hour each month; equity vesting continues during consultation.

## SEC filing metadata
- accession: 0001193125-24-209907
- form_type: 8-K
- ticker: KPTI
- cik: 0001503802
- company_name: Karyopharm Therapeutics Inc.
- filed_at: 2024-08-29T23:59:59+00:00
- event_type: leadership
- sentiment: negative
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 5.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1503802/000119312524209907/0001193125-24-209907-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1503802/000119312524209907/d883504d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-24-209907
- JSON: https://secwatch.observer/filing/0001193125-24-209907.json
- Plain text: https://secwatch.observer/filing/0001193125-24-209907.txt

## Key facts
- Executive change
  Michael Mason resigned as Executive Vice President, Chief Financial Officer and Treasurer at Karyopharm Therapeutics Inc..
  - Action: resigned
  - Role: Executive Vice President, Chief Financial Officer and Treasurer
  source text: On August 26, 2024, Michael Mason notified Karyopharm Therapeutics Inc. (the “Company”) of his intention to resign as the Company’s Executive Vice President, Chief Financial Officer and Treasurer to pursue other professional interests.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1503802/000119312524209907/0001193125-24-209907-index.htm

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