Karyopharm Therapeutics (KPTI): Commodore Capital now reports 0.0% ownership

Rhea-AI Filing Summary

Karyopharm Therapeutics Inc. is the subject of an amended Schedule 13G filing in which Commodore Capital LP, Commodore Capital Master LP, Robert Egen Atkinson, and Michael Kramarz (each a “Filer”) report that they beneficially own 0.00 shares of Karyopharm common stock, representing 0.0% of the class. The filing states that each Filer has no sole or shared voting power and no sole or shared dispositive power over any Karyopharm common shares, indicating ownership of 5 percent or less of the class as of June 30, 2026.

Key Figures

Beneficially owned shares: 0.00 shares Percent of class: 0.0 % Ownership threshold: 5 percent or less +1 more

4 metrics

Beneficially owned shares 0.00 shares Amount beneficially owned by each Filer as reported on cover pages

Percent of class 0.0 % Percent of Karyopharm common stock reported by each Filer

Ownership threshold 5 percent or less Item 5 states ownership of 5 percent or less of the class

Event date 06/30/2026 Date associated with the Schedule 13G/A amendment

Key Terms

beneficially owned, sole dispositive power, shared voting power, Schedule 13G, +1 more

5 terms

beneficially owned financial

"Amount beneficially owned: See Item 9 of the cover page for each Filer."

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

sole dispositive power financial

"Sole Dispositive Power 0.00 8 | Shared Dispositive Power 0.00"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

shared voting power financial

"6 | Shared Voting Power 0.00 7 | Sole Dispositive Power 0.00"

Shared voting power occurs when two or more parties jointly have the right to vote or decide how a block of company shares is cast, like co-owners who must agree before moving a piece of furniture. Investors care because who controls voting rights affects board elections, major corporate decisions and takeover outcomes, and shared control can alter regulatory disclosures and the practical influence any holder has over a company’s direction and value.

Schedule 13G regulatory

"Item 5. | Ownership of 5 Percent or Less of a Class."

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

Joint Filing Agreement regulatory

"Exhibit Information Exhibit 1: Joint Filing Agreement"

FAQ

What does Karyopharm Therapeutics (KPTI) latest Schedule 13G/A disclose about Commodore Capital’s stake?

The filing reports that Commodore Capital LP and related Filers now beneficially own 0.00 shares of Karyopharm Therapeutics common stock, representing 0.0% of the class, with no sole or shared voting or dispositive power reported.

Who are the Filers in the Karyopharm Therapeutics (KPTI) Schedule 13G/A amendment?

The Filers are Commodore Capital LP, Commodore Capital Master LP, Robert Egen Atkinson, and Michael Kramarz. Each is identified as a separate “Filer,” with Commodore Capital LP classified as an investment adviser (IA) and Atkinson and Kramarz as HC.

What percentage of Karyopharm Therapeutics (KPTI) shares do the Filers report owning?

Each Filer reports beneficial ownership of 0.0% of Karyopharm Therapeutics’ common stock. Correspondingly, the cover information shows 0.00 shares beneficially owned and no sole or shared voting or dispositive power for any of the Filers.

What does the Schedule 13G/A say about voting and dispositive power over Karyopharm (KPTI) shares?

For each Filer, the Schedule 13G/A shows 0.00 shares with sole voting power, shared voting power, sole dispositive power, and shared dispositive power. This indicates no reported authority to vote or dispose of Karyopharm Therapeutics common stock.

What ownership threshold is referenced in the Karyopharm Therapeutics (KPTI) Schedule 13G/A?

Item 5 specifies that the Filers have ownership of 5 percent or less of Karyopharm’s common stock. Combined with the reported 0.00 shares and 0.0% of the class, this confirms they are below the 5% reporting threshold.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/14/2026 - 04:20 PM Accepted by SEC EDGAR 08/14/2026 - 04:14 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

Karyopharm Therapeutics Inc.

(Name of Issuer)

Common Stock, $0.0001 par value

(Title of Class of Securities)

48576U205

(CUSIP Number)

6/30/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 48576U205

1

Names of Reporting Persons

Commodore Capital LP

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

0.0 %

12

Type of Reporting Person (See Instructions)

IA, PN

SCHEDULE 13G

CUSIP Number(s): 48576U205

1

Names of Reporting Persons

Commodore Capital Master LP

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

0.0 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP Number(s): 48576U205

1

Names of Reporting Persons

Robert Egen Atkinson

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

0.0 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

CUSIP Number(s): 48576U205

1

Names of Reporting Persons

Michael Kramarz

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

0.0 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Karyopharm Therapeutics Inc.
(b)	Address of issuer's principal executive offices: 85 Wells Avenue, 2nd Floor, Newton, MASSACHUSETTS, 02459.
Item 2.
(a)	Name of person filing: Commodore Capital LP Commodore Capital Master LP Robert Egen Atkinson Michael Kramarz Each a "Filer."
(b)	Address or principal business office or, if none, residence: The address for Commodore Capital LP, Robert Egen Atkinson, and Michael Kramarz is 444 Madison Avenue, Floor 35, New York, NY 10022. The address for Commodore Capital Master LP is c/o Maples Corporate Services Limited, Ugland House, South Church Street, PO Box 309, Grand Cayman KY1-1104, Cayman Islands.
(c)	Citizenship: See Item 4 of the cover page for each Filer.
(d)	Title of class of securities: Common Stock, $0.0001 par value
(e)	CUSIP No.: 48576U205
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: See Item 9 of the cover page for each Filer.
(b)	Percent of class: See Item 11 of the cover page for each Filer.
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: See Item 5 of the cover page for each Filer.
	(ii) Shared power to vote or to direct the vote: See Item 6 of the cover page for each Filer.
	(iii) Sole power to dispose or to direct the disposition of: See Item 7 of the cover page for each Filer.
	(iv) Shared power to dispose or to direct the disposition of: See Item 8 of the cover page for each Filer.
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

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

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Commodore Capital LP

Signature:	Michael Kramarz
Name/Title:	Managing Partner
Date:	08/14/2026

Commodore Capital Master LP

Signature:	Michael Kramarz
Name/Title:	Authorized Signatory
Date:	08/14/2026

Robert Egen Atkinson

Signature:	Robert Egen Atkinson
Name/Title:	Authorized Signatory
Date:	08/14/2026

Michael Kramarz

Signature:	Michael Kramarz
Name/Title:	Authorized Signatory
Date:	08/14/2026

Exhibit Information

Exhibit 1: Joint Filing Agreement