[Form 4] Altimmune, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Altimmune, Inc. (ALT) director Klaus Schafer reported receipt of a stock option award on 09/25/2025 that grants the right to buy 48,800 shares of common stock at an exercise price of $3.92 per share. The option becomes exercisable in substantially equal monthly installments over the 12 months following the grant date, subject to continued service, and expires on 09/25/2035. Following the reported transaction, the reporting person beneficially owns 48,800 option shares directly. The filing was submitted via counsel and signed by an attorney-in-fact on 09/29/2025.

Positive

• Equity alignment: Director receives options that tie compensation to share-price performance, aligning interests with shareholders.
• Retention-focused vesting: Monthly vesting over 12 months encourages continued service through the next year.
• Long exercise window: 10-year term (expiration 09/25/2035) provides flexibility for long-term value realization.

Negative

• None.

Insights

Corporate Governance Expert

TL;DR: A routine director option grant that aligns interests with shareholders without indicating material governance change.

The option award to a director is a common component of director compensation designed to align long-term interests between the board member and shareholders. The 10-year term and 12-month vesting schedule suggest the grant is intended to retain service over the near term while providing longer-term upside. There is no evidence in the filing of accelerated vesting, repricing, or related-party transactions beyond the standard director relationship. For governance assessment, this appears customary rather than extraordinary.

Compensation Analyst

TL;DR: The award is a standard equity compensation instrument with modest immediate dilution impact and a typical vesting profile.

Key compensation features: 48,800 option shares at a $3.92 strike, exercisable monthly over 12 months beginning 09/25/2025, expiring 09/25/2035. The structure provides abbreviated time-to-vesting (one year) which can be seen as retention-focused for the coming year. The filing does not disclose the grant-date fair value or the company’s outstanding share count, so absolute dilution and grant value cannot be calculated from this document alone.

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

OMB Number:			3235-0287
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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^*

Schafer Klaus

(Last) (First) (Middle)

C/O ALTIMMUNE, INC., 910 CLOPPER ROAD,

SUITE 201S

(Street)

GAITHERSBURG MD 20878

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Altimmune, Inc. [ ALT ]

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)
09/25/2025

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

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
Stock Options (option to buy)	$3.92	09/25/2025		A		48,800		(1)	09/25/2035	Common Stock, par value $0.0001	48,800	$0.00	48,800	D

Explanation of Responses:

1. The shares underlying the option become vested and exercisable in substantially equal monthly installments over the 12 months following September 25, 2025, subject to the reporting person's continued service through the applicable vesting date.

Remarks:

Exhibit 24 - Power of Attorney

	/s/ Gregory Weaver, as Attorney-in-Fact	09/29/2025
	** 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 did Klaus Schafer report on Form 4 for Altimmune (ALT)?

He reported a stock option award to purchase 48,800 shares at an exercise price of $3.92 per share, granted on 09/25/2025.

When do the options granted to Klaus Schafer vest and expire?

The options vest in substantially equal monthly installments over the 12 months following 09/25/2025 and expire on 09/25/2035.

How many shares does Klaus Schafer beneficially own after the reported transaction?

The filing reports beneficial ownership of 48,800 option shares following the transaction.

What is the exercise price of the options reported on the Form 4?

The exercise (conversion) price is $3.92 per share.

Who signed the Form 4 filing for Klaus Schafer?

The form was signed by Gregory Weaver, as Attorney-in-Fact, on 09/29/2025.