Beneficial Ownership Report · SCHEDULE 13G/A
Karyopharm Therapeutics Inc.
KPTINASDAQEQUITYCurrent
Beneficial Ownership Report
Structured filing — SCHEDULE 13G/A
primary_doc.xml
Amendment · This filing reports the amendment as submitted.
Subject company
- Company
- Karyopharm Therapeutics Inc.
- Company CIK
- 0001503802
- Street
- 85 WELLS AVENUE
- City
- NEWTON
- State / country code
- MA
- Postal code
- 02459
Statement details
- Amendment number
- 1
- Security class
- Common Stock, $0.0001 Par Value
- Event date
- 09/22/2026
- Rule designation
- Rule 13d-1(c)
Reporting person 1
- Name
- ACORN BIOVENTURES, L.P.
- Citizenship / organization
- DE
- Reporting person type
- PN
- Group designation
- b
- Aggregate amount owned
- 539,373.00
- Percent of class
- 2.4
- Sole voting power
- 0.00
- Shared voting power
- 539,373.00
- Sole dispositive power
- 0.00
- Shared dispositive power
- 539,373.00
Reporting person 2
- Name
- ACORN CAPITAL ADVISORS GP, LLC
- Citizenship / organization
- DE
- Reporting person type
- OO
- Group designation
- b
- Aggregate amount owned
- 539,373.00
- Percent of class
- 2.4
- Sole voting power
- 0.00
- Shared voting power
- 539,373.00
- Sole dispositive power
- 0.00
- Shared dispositive power
- 539,373.00
Reporting person 3
- Name
- ACORN BIOVENTURES 2, L.P.
- Citizenship / organization
- DE
- Reporting person type
- PN
- Group designation
- b
- Aggregate amount owned
- 744,848.00
- Percent of class
- 3.3
- Sole voting power
- 0.00
- Shared voting power
- 744,848.00
- Sole dispositive power
- 0.00
- Shared dispositive power
- 744,848.00
Reporting person 4
- Name
- Acorn Capital Advisors GP 2, LLC
- Citizenship / organization
- DE
- Reporting person type
- OO
- Group designation
- b
- Aggregate amount owned
- 744,848.00
- Percent of class
- 3.3
- Sole voting power
- 0.00
- Shared voting power
- 744,848.00
- Sole dispositive power
- 0.00
- Shared dispositive power
- 744,848.00
Reporting person 5
- Name
- Anders Hove
- Citizenship / organization
- X1
- Reporting person type
- IN
- Group designation
- b
- Aggregate amount owned
- 1,284,221.00
- Percent of class
- 5.7
- Sole voting power
- 0.00
- Shared voting power
- 1,284,221.00
- Sole dispositive power
- 0.00
- Shared dispositive power
- 1,284,221.00
Item 1
Issuer
Karyopharm Therapeutics Inc.
Principal executive office address
85 WELLS AVENUE, NEWTON, MASSACHUSETTS, 02459.
Item 2
Citizenship
Acorn Bioventures, L.P. and Acorn Bioventures 2 L.P. are both Delaware limited partnerships. Acorn Capital Advisors GP, LLC and Acorn Capital Advisors GP 2, LLC are both Delaware limited liability companies. Anders Hove is a citizen of the United States of America.
Filing person
Acorn Bioventures, L.P. Acorn Capital Advisors GP, LLC Acorn Bioventures 2, L.P. Acorn Capital Advisors GP2, LLC Anders Hove
Principal business or residence address
420 Lexington Avenue, Suite 2626, New York, New York 10170
Item 3
Not applicable indication
Y
Item 4
Percent of class
The percentages set forth herein are calculated based upon 22,681,460 shares of Common Stock outstanding as of June 30, 2026 as reported in the Issuer's Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2026 filed with the Securities and Exchange Commission on August 13, 2026.
Amount beneficially owned
The information required by Items 4(a) - (c) is set forth in Rows (5) - (11) of the cover page for each Reporting Person hereto and is incorporated herein by reference for each Reporting Person.
Sole voting power
Acorn Capital Advisors GP, LLC is the General Partner of Acorn Bioventures, L.P. and may be deemed to beneficially own the shares of Common Stock beneficially owned by Acorn Bioventures, L.P. Acorn Capital Advisors GP 2, LLC is the General Partner of Acorn Bioventures 2, L.P. and may be deemed to beneficially own the shares of Common Stock beneficially owned by Acorn Bioventures 2, L.P.
Shared voting power
Anders Hove, in his capacity as Manager of each of Acorn Capital Advisors GP, LLC and Acorn Capital Advisors GP 2, LLC, may be deemed to beneficially own the shares beneficially owned by each of Acorn Capital Advisors GP, LLC and Acorn Capital Advisors GP 2, LLC.
Sole dispositive power
NA
Shared dispositive power
NA
Item 5
Not applicable indication
Y
Item 6
Not applicable indication
Y
Item 7
Not applicable indication
Y
Item 8
Not applicable indication
Y
Item 9
Not applicable indication
Y
Item 10
Not applicable indication
N
Certifications
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.
Signature 1
- Reporting person
- ACORN BIOVENTURES, L.P.
- Signed
- Anders Hove
- Title
- Manager of General Partner
- Date
- 09/25/2026
Signature 2
- Reporting person
- ACORN CAPITAL ADVISORS GP, LLC
- Signed
- Anders Hove
- Title
- Manager
- Date
- 09/25/2026
Signature 3
- Reporting person
- ACORN BIOVENTURES 2, L.P.
- Signed
- Anders Hove
- Title
- Manager of General Partner
- Date
- 09/25/2026
Signature 4
- Reporting person
- Acorn Capital Advisors GP 2, LLC
- Signed
- Anders Hove
- Title
- Manager
- Date
- 09/25/2026
Signature 5
- Reporting person
- Anders Hove
- Signed
- Anders Hove
- Title
- Manager
- Date
- 09/25/2026
Company context
Karyopharm Therapeutics is a commercial-stage pharmaceutical company pioneering the science of nuclear export inhibition to develop differentiated therapies for patients with cancer. The Company's lead therapy, XPOVIO® (selinexor), is a first-in-class inhibitor of exportin 1 (XPO1). XPOVIO is marketed by the Company in the U.S. for adults with relapsed or refractory multiple myeloma and is approved as XPOVIO or NEXPOVIO® in more than 50 ex-U.S. countries and territories. Building on its leadership in XPO1 biology, Karyopharm is advancing selinexor's potential in hematological cancers, including in myelofibrosis. The Company is also exploring opportunities to evaluate XPO1 inhibition across myeloproliferative neoplasms using next-generation compounds, including eltanexor. Headquartered in Newton, Massachusetts, Karyopharm has an established, efficient, and scalable commercial infrastructure to bring novel therapeutic options to patients with cancer. For more information, visit www.karyopharm.com and follow Karyopharm on LinkedIn and on X at @Karyopharm.
Current securities
Recent company filings
- Material Modification to Rights of Security Holders · Amendments to Articles of Incorporation or Bylaws; Change in Fiscal YearSep 18, 2026
- Entry into a Material Definitive Agreement · Triggering Events That Accelerate or Increase a Direct Financial Obligation · Unregistered Sales of Equity Securities · Other EventsSep 11, 2026
- Other EventsAug 31, 2026
- SCHEDULE 13G/A - filed by Commodore Capital LP regarding Karyopharm Therapeutics Inc.Aug 14, 2026
- 10-Q filingAug 13, 2026