---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-24-248162"
form_type: "8-K"
ticker: "KPTI"
cik: "0001503802"
company_name: "Karyopharm Therapeutics Inc."
filed_at: "2024-10-31T23:59:59+00:00"
generated_at: "2026-05-30T07:23:33.083768+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Karyopharm changes co-primary endpoint for Phase 3 SENTRY trial to Abs-TSS; increases sample size to 350

## Summary
- Co-primary endpoint changed from TSS50 to Abs-TSS following FDA alignment; SVR35 remains co-primary.
- Phase 1 Selinexor+ruxolitinib data showed 79% SVR35 (n=14) and 18.5-point average Abs-TSS improvement (n=9) at week 24.
- Total sample size increased to ~350 patients to improve statistical power; top-line data still expected in 2H 2025.
- Safety profile remains consistent with no new signals; change supported by key investigators and MPN Research Foundation.

## SEC filing metadata
- accession: 0001193125-24-248162
- form_type: 8-K
- ticker: KPTI
- cik: 0001503802
- company_name: Karyopharm Therapeutics Inc.
- filed_at: 2024-10-31T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1503802/000119312524248162/0001193125-24-248162-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1503802/000119312524248162/d891084d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-24-248162
- JSON: https://secwatch.observer/filing/0001193125-24-248162.json
- Plain text: https://secwatch.observer/filing/0001193125-24-248162.txt

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