Altimmune (ALT) CSO receives stock option and RSU equity awards

Rhea-AI Filing Summary

Altimmune, Inc. Chief Scientific Officer M Scot Roberts reported equity awards consisting of stock options and restricted stock units. He was granted 222,670 stock options with an exercise price of $0.0000 per share, all held as direct ownership.

The options vest over four years, with 25% vesting on February 26, 2027 and the rest vesting in equal monthly installments over the following 36 months, subject to continued service. Roberts also received 95,430 restricted stock units, each representing one share of common stock when vested.

The RSUs vest over four years, with 25% vesting on February 26, 2027 and the remaining units vesting in equal annual installments over the next three years, contingent on his continued service. These awards reflect non-cash compensation rather than open-market share purchases or sales.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider Roberts M Scot

Role Chief Scientific Officer

Type	Security	Shares	Price	Value
Grant/Award	Stock Options (option to buy)	222,670	$0.00	--
Grant/Award	Restricted Stock Units	95,430	$0.00	--

Holdings After Transaction: Stock Options (option to buy) — 222,670 shares (Direct); Restricted Stock Units — 95,430 shares (Direct)

Footnotes (1)

1. The shares underlying the option become vested and exercisable over four (4) years with 25% of the shares vesting on February 26, 2027, with the remainder vesting in equal monthly installments for the following thirty-six (36) months, subject to the reporting person's continued service on each applicable vesting date. Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Common Stock, par value $0.0001, when vested. The RSUs become vested over four (4) years with 25% of the shares vesting February 26, 2027, with the remainder vesting in equal annual installments for the following three (3) years, subject to the reporting person's continued service through the applicable vesting date, and have no expiration date.

Form 4 Insider Transactions: What Each Field Means →

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
Estimated average burden
hours per response:			0.5

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

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Roberts M Scot

(Last) (First) (Middle)

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)

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

3. Date of Earliest Transaction (Month/Day/Year)
02/26/2026

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)	$4.46	02/26/2026		A		222,670		(1)	02/26/2036	Common Stock, par value $0.0001	222,670	$0	222,670	D
Restricted Stock Units	(2)	02/26/2026		A		95,430		(3)	(3)	Common Stock, par value $0.0001	95,430	$0	95,430	D

Explanation of Responses:

1. The shares underlying the option become vested and exercisable over four (4) years with 25% of the shares vesting on February 26, 2027, with the remainder vesting in equal monthly installments for the following thirty-six (36) months, subject to the reporting person's continued service on each applicable vesting date.

2. Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Common Stock, par value $0.0001, when vested.

3. The RSUs become vested over four (4) years with 25% of the shares vesting February 26, 2027, with the remainder vesting in equal annual installments for the following three (3) years, subject to the reporting person's continued service through the applicable vesting date, and have no expiration date.

	/s/ Gregory Weaver, as Attorney-in-Fact	02/27/2026
	** 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 transactions did Altimmune (ALT) report for M Scot Roberts?

Altimmune reported that Chief Scientific Officer M Scot Roberts received grants of 222,670 stock options and 95,430 restricted stock units. Both awards are held directly and represent non-cash equity compensation, not open-market buying or selling of Altimmune common stock.

How many stock options were granted to Altimmune (ALT) CSO M Scot Roberts?

M Scot Roberts received 222,670 stock options from Altimmune. These options vest over four years, starting with 25% on February 26, 2027, followed by equal monthly vesting over 36 months, subject to his continued service with the company.

What are the terms of the restricted stock units granted by Altimmune (ALT)?

Altimmune granted 95,430 restricted stock units to M Scot Roberts. Each RSU converts into one share of common stock upon vesting, with 25% vesting on February 26, 2027 and the remainder vesting in equal annual installments over the following three years.

Are the Altimmune (ALT) awards to M Scot Roberts immediate share ownership?

The awards are not immediate full share ownership. The stock options must be vested and then exercised to become shares, while each restricted stock unit converts into one common share only as it vests over the four-year schedule.

Is the Form 4 for Altimmune (ALT) a buy or sell transaction?

The Form 4 reflects equity award grants, categorized as acquisitions, rather than market buys or sells. M Scot Roberts received stock options and restricted stock units as part of compensation, with vesting tied to his continued service at Altimmune.

What conditions affect vesting of Altimmune (ALT) equity awards to M Scot Roberts?

Vesting of both the stock options and restricted stock units requires M Scot Roberts’ continued service. Options vest 25% on February 26, 2027 then monthly over 36 months, while RSUs vest 25% on that date and annually over the following three years.