Janus Henderson Group plc reported beneficial ownership of 4,802,002 shares of Immix Biopharma, Inc. common stock, representing 9.1% of the class as disclosed on this Schedule 13G/A. The filing states the shares are held through multiple asset managers that exercise shared voting and dispositive power on behalf of managed portfolios.
The filing notes that the managed portfolios are the record holders entitled to dividends and sale proceeds, and that only Janus Henderson Biotech Innovation Master Fund Ltd. holds more than 5% with dividend/proceeds rights. The reporting person disclaims rights to receive dividends or sale proceeds for the asset managers described.
Positive
None.
Negative
None.
Insights
Large institutional stake of 9.1% reported via multiple asset managers.
Janus Henderson Group plc is disclosed as beneficial owner of 4,802,002 shares, with shared voting and dispositive power across its asset-manager affiliates. The holding is presented as managed on behalf of client portfolios rather than held for the reporting entities' own economic benefit.
Investor implications depend on portfolio-level decisions; the filing clarifies that the managed portfolios receive dividends and proceeds. Subsequent filings would show any material transfers or changes in voting power.
Disclosure emphasizes delegation structure and reporting posture.
The Schedule 13G/A lists multiple Janus Henderson investment affiliates that exercise voting/dispositive discretion for client accounts, producing a shared power figure of 4,802,002 shares. The filer disclaims dividend/proceeds rights for the asset managers while identifying one fund with direct economic rights exceeding 5%.
The statement on irrevocable delegation and reporting status signals that the parent is avoiding separate Section 13(d)/(g) reporting for the delegating fund; future updates would be filed if control or ownership thresholds change.
Key Figures
Beneficial ownership:4,802,002 sharesOwnership percent:9.1%Sole voting power:0 shares+3 more
6 metrics
Beneficial ownership4,802,002 sharesAmount beneficially owned as reported on Schedule 13G/A
Ownership percent9.1%Percent of class reported in Item 4(b)
Sole voting power0 sharesItem 4(c)(i) sole power to vote
Shared voting power4,802,002 sharesItem 4(c)(ii) shared power to vote
Signer and dateKristin Mariani; 5/15/2026Signature block on the amendment
CUSIP45258H106Issuer CUSIP for Immix Biopharma common stock
"may be deemed to be the beneficial owner of 4,802,002 common stock"
A beneficial owner is the person who ultimately owns or controls a financial asset or property, even if their name isn't directly on official documents. Think of it like someone who secretly holds the keys to a safe deposit box—others may appear to have access, but the true owner is the one who benefits from what's inside. Identifying beneficial owners helps ensure transparency and prevent illegal activities like money laundering or fraud.
Shared dispositive powerregulatory
"Shared Dispositive Power 4,802,002.00"
Schedule 13G/Aregulatory
"IMMIX BIOPHARMA, INC. Common Stock 45258H106 (Amendment No. 1)"
A Schedule 13G/A is an amended public filing with the U.S. securities regulator that updates a previous Schedule 13G, disclosing when an individual or group holds a substantial (typically over 5%) stake in a company and is claiming a passive, non‑controlling intent. Investors monitor these updates because rising or falling holdings can signal changing confidence, potential future moves, or shifts in voting power — like watching a public ledger where large shareholders quietly adjust their positions.
Irrevocable delegationother
"irrevocable delegation of investment and voting discretion to an Asset Manager"
Janus Henderson reports beneficial ownership of 4,802,002 shares, equal to 9.1% of Immix Biopharma's common stock as stated in the filing. This figure reflects shared voting and dispositive power exercised by affiliated asset managers on behalf of clients.
Who actually receives dividends and sale proceeds for these IMMX shares?
The filing states the managed portfolios hold the economic rights and have the right to receive dividends and proceeds. The asset managers exercise voting/dispositive discretion but disclaim the right to receive dividends or sale proceeds for those managed accounts.
Does Janus Henderson identify any fund owning more than 5% of IMMX?
Yes. The Schedule 13G/A identifies Janus Henderson Biotech Innovation Master Fund Ltd. as a managed portfolio that holds more than 5% of Immix Biopharma common stock and has the right to receive dividends and proceeds.
What voting and disposition powers are reported for the 4,802,002 shares?
The filing reports 0 shares as sole voting or dispositive power and 4,802,002 shares as shared voting power and shared dispositive power, indicating collective control through the asset-manager group.
Who signed the Schedule 13G/A filing for Janus Henderson?
The filing is signed by Kristin Mariani, listed as Head of North America Compliance, on 5/15/2026, as shown on the submitted Schedule 13G/A amendment.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 1)
IMMIX BIOPHARMA, INC.
(Name of Issuer)
Common Stock
(Title of Class of Securities)
45258H106
(CUSIP Number)
03/31/2026
(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):
45258H106
1
Names of Reporting Persons
JANUS HENDERSON GROUP PLC
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
JERSEY
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
4,802,002.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
4,802,002.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
4,802,002.00
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)
9.1 %
12
Type of Reporting Person (See Instructions)
HC
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
IMMIX BIOPHARMA, INC.
(b)
Address of issuer's principal executive offices:
11400 WEST OLYMPIC BLVD., SUITE 200
LOS ANGELES, CA 90064
Item 2.
(a)
Name of person filing:
Janus Henderson Group plc
(b)
Address or principal business office or, if none, residence:
201 Bishopsgate
EC2M 3AE, United Kingdom
(c)
Citizenship:
Y9
(d)
Title of class of securities:
Common Stock
(e)
CUSIP No.:
45258H106
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:
Janus Henderson Group plc (JHG) is the ultimate parent of a number of SEC-registered investment advisers and foreign equivalents thereof, including but not limited to Janus Henderson Investors US LLC, Janus Henderson Investors UK Limited, Janus Henderson Investors Australia Institutional Funds Management Limited, Janus Henderson Investors Middle East Limited, Janus Henderson Investors (Jersey) Limited, Janus Henderson Investors (Japan) Limited, Janus Henderson Investors (Singapore) Limited, Kapstream Capital Pty Limited, Privacore Capital Advisors LLC, Tabula Investment Management Limited, and Victory Park Capital Advisors LLC (each, an Asset Manager and together, the Asset Managers). The Asset Managers generally exercise investment and/or voting discretion on behalf of their clients which include investment companies, other investment advisers, institutional separate accounts and retail separate accounts (collectively referred to herein as Managed Portfolios).
As a result of their exercise of investment and/or voting discretion on behalf of the Managed Portfolios, the Asset Managers may be deemed to be the beneficial owner of 4,802,002 common stock of Immix Biopharma, Inc. However, the Asset Managers do not have the right to receive any dividends from, or the proceeds from the sale of, the securities held in the Managed Portfolios and disclaim any ownership associated with such rights.
(b)
Percent of class:
9.1 %
(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:
4802002
(iii) Sole power to dispose or to direct the disposition of:
0
(iv) Shared power to dispose or to direct the disposition of:
4802002
Item 5.
Ownership of 5 Percent or Less of a Class.
Not Applicable
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 Managed Portfolios have the right to receive all dividends from, and the proceeds from the sale of, the securities held in their respective accounts.
Of the Managed Portfolios, only the Janus Henderson Biotech Innovation Master Fund Ltd. has the right to receive dividends from, or the proceeds from the sale of, more than five percent of the common stock of Immix Biopharma, Inc. Due to an irrevocable delegation of investment and voting discretion to an Asset Manager on less than 60 days notice, the Fund is not considered a Reporting Person under Section 13(d) and (g).
Item 7.
Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary.
Please refer to Exhibit 99.
Item 8.
Identification and Classification of Members of the Group.
If a group has filed this schedule pursuant to §240.13d-1(b)(1)(ii)(J), so indicate under Item 3(j) and attach an exhibit stating the identity and Item 3 classification of each member of the group. If a group has filed this schedule pursuant to §240.13d-1(c) or §240.13d-1(d), attach an exhibit stating the identity of each member of the group.
N/A
Item 9.
Notice of Dissolution of Group.
Notice of dissolution of a group may be furnished as an exhibit stating the date of the dissolution and that all further filings with respect to transactions in the security reported on will be filed, if required, by members of the group, in their individual capacity. See Item 5.
N/A
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.
