IMRX Form 4: Peter Feinberg Acquires 5,000 Class A Shares

Rhea-AI Filing Summary

Peter Feinberg, a director of Immuneering Corp (IMRX), reported a purchase of 5,000 Class A common shares on 09/29/2025 at a price of $7.18 per share. After the transaction he beneficially owns 141,766 shares directly, plus additional indirect holdings through entities (392,242; 476,615; 115,441), as listed on the Form 4. The filing was signed by an attorney-in-fact on 09/30/2025. This Form 4 discloses an insider purchase that increases the reporting person’s stake but contains no other financial metrics or commentary.

Positive

• Director purchase disclosed: Peter Feinberg acquired 5,000 Class A shares on 09/29/2025.
• Specific price provided: Transaction executed at $7.18 per share, allowing clear valuation of the trade.
• Clear ownership detail: Form shows post-transaction direct ownership of 141,766 shares and detailed indirect holdings through named entities.

Negative

• None.

Insights

Securities Analyst

TL;DR: A routine insider purchase: director bought 5,000 shares at $7.18, modestly increasing direct ownership.

The Form 4 shows a straightforward open-market acquisition of 5,000 Class A shares by director Peter Feinberg on 09/29/2025 at $7.18 per share. The filing lists his direct holdings as 141,766 shares and substantial indirect interests through multiple entities. There are no derivative transactions or dispositions reported. For investors, this is a routine insider buy disclosure without additional context on timing or intent.

Corporate Governance Expert

TL;DR: Compliance filing appears standard; transaction properly reported by a director via Form 4.

The submission follows Section 16 reporting conventions: transaction code 'P' (purchase) is used, ownership breakdown includes direct and indirect interests, and the form is signed by an attorney-in-fact. There are no amendments, derivatives, or unusual holding structures disclosed beyond common GP relationships. The filing indicates routine governance transparency rather than a material corporate action.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

Feinberg Peter

(Last) (First) (Middle)

245 MAIN STREET

SECOND FLOOR

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Immuneering Corp [ IMRX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
09/29/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Class A Common Stock	09/29/2025		P		5,000	A	$7.18	141,766	D
Class A Common Stock								392,242	I	General Partner of PF Associates L.P.
Class A Common Stock								476,615	I	General Partner of PEF LLC.
Class A Common Stock								115,441	I	General Partner of S4K Investments LLC.

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

Remarks:

	/s/ Michael D. Bookman, Attorney-in-Fact for Peter Feinberg	09/30/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did Immuneering (IMRX) report on 09/29/2025?

The Form 4 reports that director Peter Feinberg purchased 5,000 Class A shares on 09/29/2025 at $7.18 per share.

How many shares does Peter Feinberg beneficially own after the reported transaction?

The filing shows 141,766 shares directly owned after the purchase, plus indirect holdings of 392,242, 476,615, and 115,441 through affiliated entities.

Was the Form 4 for IMRX an individual filing or joint/group filing?

The Form indicates it was filed by one reporting person (individual filing).

Did the Form 4 disclose any derivative transactions or dispositions?

No. Table II (derivative securities) shows no transactions and only the non-derivative purchase in Table I is reported.

Who signed the Form 4 for Peter Feinberg?

The form was signed by Michael D. Bookman, Attorney-in-Fact for Peter Feinberg on 09/30/2025.