Christophe Arbet-Engels - 01 Oct 2025 Form 4 Insider Report for Altimmune, Inc. (ALT)

Reporting relationship: Chief Medical Officer
Issuer ticker: ALT
Reported as of: 01 Oct 2025
Net transaction value: $0
SEC form: 4
Accepted by SEC: 03 Oct 2025, 16:23:25 UTC
Prior SEC filing: 14 Feb 2025
Source filing: View source filing
Reporting owner signature: /s/ Gregory Weaver, as Attorney-in-Fact

Key filing fact

Christophe Arbet-Engels filed Form 4 for Altimmune, Inc. (ALT) on 03 Oct 2025.

Key facts

This page summarizes Christophe Arbet-Engels's Form 4 filing for Altimmune, Inc. (ALT).
2 reported transactions and 2 derivative rows are listed below.
Accepted by SEC: 03 Oct 2025, 16:23.

Change

Previous filing in this sequence was filed on 14 Feb 2025.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001802615 Primary reporting owner

Arbet-Engels Christophe

Relationship: Chief Medical Officer
Address: C/O ALTIMMUNE, INC., 910 CLOPPER ROAD, SUITE 201S, GAITHERSBURG
Signature: /s/ Gregory Weaver, as Attorney-in-Fact
Signature date: 03 Oct 2025

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

ALT transaction Derivative

Stock Options (option to buy)

Award

Transaction value: $0
Shares: +450,000
Change %
Price: $0.000000
Shares after: 450,000
Date: 01 Oct 2025
Ownership: Direct
Underlying class: Common Stock, par value $0.0001
Underlying amount: 450,000
Exercise price: $3.87
Footnotes: F1

ALT transaction Derivative

Restricted Stock Units

Award

Transaction value: $0
Shares: +150,000
Change %
Price: $0.000000
Shares after: 150,000
Date: 01 Oct 2025
Ownership: Direct
Underlying class: Common Stock, par value $0.0001
Underlying amount: 150,000
Exercise price
Footnotes: F2, F3

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 3 footnotes

Footnote F1

The shares underlying the option become vested and exercisable over four (4) years with 25% of the shares vesting on October 1, 2026, 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.

Footnote F2

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

Footnote F3

The RSUs become vested over four (4) years with 25% of the shares vesting October 1, 2026, 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.