RA CAPITAL MANAGEMENT, L.P. - 26 Mar 2026 SCHEDULE 13G Report for Karyopharm Therapeutics Inc. Common Stock, $0.0001 par value per share (KPTI)

Filing Manager
RA CAPITAL MANAGEMENT, L.P.
Reporting Manager
RA Capital Management, L.P.
Security
Karyopharm Therapeutics Inc. Common Stock, $0.0001 par value per share
Symbol
KPTI
Shares outstanding
20,999,121 shares
Disclosed Ownership
2,078,913 shares
Ownership
9.9%
Form type
SCHEDULE 13G
Filing time
02 Apr 2026, 16:47:09 UTC
Date of event
26 Mar 2026
SEC
View on sec.gov

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Quoteable Key Fact

"RA CAPITAL MANAGEMENT, L.P. disclosed 9.9% ownership in Karyopharm Therapeutics Inc. Common Stock, $0.0001 par value per share (KPTI) on 26 Mar 2026."

Quick Takeaways

  • RA CAPITAL MANAGEMENT, L.P. filed SCHEDULE 13G for Karyopharm Therapeutics Inc. Common Stock, $0.0001 par value per share (KPTI).
  • Disclosed ownership: 9.9%.
  • Date of event: 26 Mar 2026.

What Changed

  • No earlier schedule filing is available for direct comparison.
  • Current filing was accepted on 02 Apr 2026, 16:47.

Why This Matters

  • This page explains what this Schedule 13D/13G filing tells you before manager-level rows.
  • You can verify ownership claims directly against the original SEC filing.

Official SEC Source

Backed by Schedule 13D/13G

Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.

See Original Filing

Reporting Managers (4)

Name Ownership Shares Owned sole voting power shared voting power Signature Title CIK
RA Capital Management, L.P. 9.9% 2,078,913 0 2,078,913 /s/ Peter Kolchinsky By Peter Kolchinsky, Authorized Signatory
Peter Kolchinsky 9.9% 2,078,913 0 2,078,913 /s/ Peter Kolchinsky Peter Kolchinsky
Rajeev Shah 9.9% 2,078,913 0 2,078,913 /s/ Rajeev Shah Rajeev Shah
RA Capital Healthcare Fund, L.P. 9.9% 2,078,913 0 2,078,913 /s/ Peter Kolchinsky By RA Capital Healthcare Fund GP, LLC, its General Partner, By Peter Kolchinsky, Manager

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