[SCHEDULE 13G] SELLAS Life Sciences Group, Inc. SEC Filing

Rhea-AI Filing Summary

The Vanguard Group filed a Schedule 13G reporting a passive, beneficial ownership of 6,694,799 SELLAS Life Sciences (SLS) common shares, equal to 6.7 % of the outstanding class, as of 30 June 2025. The position is held largely through warrants; Vanguard cites that the CUSIP used is assigned to SLS’s ordinary shares, but the underlying securities are warrants.

Voting vs. dispositive power:

• Sole voting power: 0 shares
• Shared voting power: 92,960 shares
• Sole dispositive power: 6,568,778 shares
• Shared dispositive power: 126,021 shares

The filing confirms the stake is held in the ordinary course of business, with no intent to influence control. Vanguard classifies itself as an investment adviser (Item 3-e). Signature by Ashley Grim, Head of Global Fund Administration, is dated 29 July 2025.

Key takeaways: Vanguard is now a >5 % holder, potentially enhancing SLS’s institutional ownership profile and trading liquidity; however, its negligible voting power limits immediate governance impact.

Positive

• Institutional endorsement: A respected global asset manager now holds 6.7 % of SLS, potentially increasing investor confidence and secondary-market liquidity.

Negative

• Limited voting power: Vanguard controls only 92,960 voting shares versus 6.69 M economic shares, curbing any immediate governance support for management or shareholders.
• Warrant structure uncertainty: Economic exposure via warrants could be divested or expire without converting, introducing conversion-timing risk.

Insights

Portfolio Manager

TL;DR Vanguard's passive 6.7 % warrant-based stake boosts institutional ownership but offers little voting clout—market-friendly yet governance-neutral.

Vanguard’s entry places a top-tier asset manager on SLS’s register, improving perception of liquidity and institutional endorsement. Because the holdings are warrants, Vanguard controls economic exposure without full voting rights; only ~93 k shares carry shared votes. Passive 13G status signals no activist intent, reducing takeover speculation. Overall, modestly positive for market sentiment but unlikely to alter strategic direction.

Corporate Governance Analyst

TL;DR Economic stake sizeable, governance influence minimal; passive filing suggests limited board-level implications.

With zero sole voting power and sub-0.1 % shared voting power, Vanguard cannot materially sway shareholder resolutions. The warrant structure may convert later, but until exercised, board influence remains negligible. Investors should not expect policy shifts or proxy support deriving from this position. The filing nonetheless obliges SLS to track Vanguard under SEC beneficial ownership rules, and any future conversions would require updated disclosures.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

SELLAS Life Sciences Group Inc

(Name of Issuer)

Common Stock

(Title of Class of Securities)

81642T209

(CUSIP Number)

06/30/2025

(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)

SCHEDULE 13G

CUSIP No. 81642T209

1

Names of Reporting Persons

The Vanguard Group

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

PENNSYLVANIA

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 92,960.00
7	Sole Dispositive Power 6,568,778.00
8	Shared Dispositive Power 126,021.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

6,694,799.00

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)

6.70 %

12

Type of Reporting Person (See Instructions)

IA

Comment for Type of Reporting Person: The holdings reported herein are in the form of warrants.The CUSIP Number listed throughout this filing is the CUSIP assigned to the Ordinary Shares of the Issuer.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: SELLAS Life Sciences Group Inc
(b)	Address of issuer's principal executive offices: 7 TIMES SQUARE, SUITE 2503, NEW YORK, NY, 10036
Item 2.
(a)	Name of person filing: The Vanguard Group
(b)	Address or principal business office or, if none, residence: 100 Vanguard Blvd., Malvern, PA 19355
(c)	Citizenship: PA
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 81642T209
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: 6694799
(b)	Percent of class: 6.7 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 0
	(ii) Shared power to vote or to direct the vote: 92960
	(iii) Sole power to dispose or to direct the disposition of: 6568778
	(iv) Shared power to dispose or to direct the disposition of: 126021
Item 5.	Ownership of 5 Percent or Less of a Class.
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. The Vanguard Group, Inc.'s clients, including investment companies registered under the Investment Company Act of 1940 and other managed accounts, have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the securities reported herein. No one other person's interest in the securities reported herein is more than 5%.
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 acquired and are held in the ordinary course of business and 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.

The Vanguard Group

Signature:	Ashley Grim
Name/Title:	Head of Global Fund Administration
Date:	07/29/2025

FAQ

How many SLS shares does Vanguard own according to the Schedule 13G?

Vanguard reports 6,694,799 shares (in warrant form) beneficially owned.

What percentage of SELLAS Life Sciences (SLS) does Vanguard’s stake represent?

The filing states a 6.7 % beneficial ownership of the outstanding common stock.

What is the effective date of Vanguard’s reportable transaction?

The date of event triggering the filing is 30 June 2025.

Does Vanguard have voting control over the SLS shares?

Vanguard has 0 sole and 92,960 shared voting shares, indicating very limited voting power.

Why are Vanguard’s holdings described as warrants instead of ordinary shares?

The filing notes the reported securities are in warrant form; the CUSIP used refers to the ordinary shares for identification.

Is Vanguard’s position intended to influence SLS management?

No. Vanguard certifies the stake was acquired in the ordinary course and not to change or influence control.