---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-25-112570"
form_type: "8-K"
ticker: "CYTK"
cik: "0001061983"
company_name: "CYTOKINETICS INC"
filed_at: "2025-09-03T23:59:59+00:00"
generated_at: "2026-05-17T08:26:25.201871+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Cytokinetics presents new aficamten data at ESC 2025; shows improvement vs metoprolol

## Summary
- MAPLE-HCM: aficamten superior to metoprolol on diastolic function, SAM, and LVOT obstruction (p<0.001); reduced max wall thickness (-1.01mm, p=0.015).
- Atrial fibrillation annual incidence with aficamten was 1.5%, consistent with predicted HCM-AF and CHARGE-AF rates; minimal clinical impact.
- Integrated safety of 463 patients (~700 patient-years) shows similar AE profile to placebo; low LVEF<50% incidence, no permanent discontinuations.
- Longer-term FOREST-HCM: 69% and 93% of patients improved NYHA class at Week 12 and 96; KCCQ-CSS +15 and +16.
- FDA NDA under review with PDUFA target action date of December 26, 2025.

## SEC filing metadata
- accession: 0000950170-25-112570
- form_type: 8-K
- ticker: CYTK
- cik: 0001061983
- company_name: CYTOKINETICS INC
- filed_at: 2025-09-03T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1061983/000095017025112570/0000950170-25-112570-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1061983/000095017025112570/cytk-20250831.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-25-112570
- JSON: https://secwatch.observer/filing/0000950170-25-112570.json
- Plain text: https://secwatch.observer/filing/0000950170-25-112570.txt

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