Apogee CEO sells 20,000 shares in planned trade

Apogee Therapeutics Chief Executive Officer Michael Thomas Henderson sold 20,000 shares of Common Stock in open-market transactions.

Rhea-AI Filing Summary

Apogee Therapeutics Chief Executive Officer Michael Thomas Henderson sold 20,000 shares of Common Stock in open-market transactions. The sales occurred on May 13, 2026 at weighted average prices of about $82.05 and $82.58 per share. The filing states these transactions were executed under a pre-arranged Rule 10b5-1 trading plan adopted on August 13, 2025. Following the sales, Henderson continues to hold over one million Apogee Therapeutics shares, so the transactions represent a small portion of his overall position.

Insider Trade Summary 10b5-1

Net Seller: 20,000 shares

Net Sell 2 txns

Insider HENDERSON MICHAEL THOMAS

Role Chief Executive Officer

Sold 20,000 shs ($1.64M)

Type	Security	Shares	Price	Value
Sale	Common Stock	18,659	$82.05	$1.53M
Sale	Common Stock	1,341	$82.58	$111K

Holdings After Transaction: Common Stock — 1,115,987 shares (Direct)

Footnotes (3)

1. F1. This transaction was executed pursuant to a Rule 10b5-1 trading plan adopted on August 13, 2025.
2. F2. The price reported above is a weighted average price. The shares were sold in multiple transactions at prices ranging from $81.455 to $82.440, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission (the "SEC"), upon request, full information regarding the number of shares sold at each separate price within the range.
3. F3. The price reported above is a weighted average price. The shares were sold in multiple transactions at prices ranging from $82.470 to $83.265, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range.

Key Figures

Shares sold: 20,000 shares Weighted average price 1: $82.58 per share Weighted average price 2: $82.05 per share +1 more

4 metrics

Shares sold 20,000 shares Total Common Stock sold on May 13, 2026

Weighted average price 1 $82.58 per share First open-market sale on May 13, 2026

Weighted average price 2 $82.05 per share Second open-market sale on May 13, 2026

Net share change -20,000 shares Net buy/sell shares across reported transactions

Key Terms

Rule 10b5-1 trading plan, weighted average price, open-market sale, Common Stock

4 terms

Rule 10b5-1 trading plan financial

"This transaction was executed pursuant to a Rule 10b5-1 trading plan adopted on August 13, 2025."

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

weighted average price financial

"The price reported above is a weighted average price. The shares were sold in multiple transactions..."

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

open-market sale financial

"transaction_action: open-market sale"

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

Common Stock financial

"security_title: Common Stock"

Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transaction did Apogee Therapeutics (APGE) report for its CEO?

Apogee Therapeutics reported that CEO Michael Thomas Henderson sold 20,000 shares of Common Stock. The transactions were open-market sales executed on May 13, 2026, under a pre-arranged Rule 10b5-1 trading plan adopted in August 2025.

At what prices did the Apogee Therapeutics (APGE) CEO sell shares?

The CEO’s transactions used weighted average prices of about $82.05 and $82.58 per share. Footnotes explain the shares were sold in multiple trades within ranges of $81.455–$82.440 and $82.470–$83.265, respectively.

How many Apogee Therapeutics (APGE) shares did the CEO sell in total?

The CEO sold a total of 20,000 Apogee Therapeutics Common Stock shares. The Form 4 shows two open-market sale transactions of 1,341 shares and 18,659 shares, both recorded on May 13, 2026, resulting in a net sell position.

Was the Apogee Therapeutics (APGE) CEO’s stock sale under a Rule 10b5-1 plan?

Yes. A footnote states the transaction was executed pursuant to a Rule 10b5-1 trading plan adopted on August 13, 2025. Such plans are pre-arranged trading programs that schedule future trades in advance, often to support routine diversification.

Does the Apogee Therapeutics (APGE) CEO still hold shares after these sales?

Yes. The Form 4 indicates Michael Thomas Henderson continues to hold over one million Apogee Therapeutics shares after the reported transactions. This means the 20,000 shares sold represent a relatively small portion of his total reported holdings.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 05/15/2026 - 08:00 PM Learn about SEC filing dates

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).

X

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^*

HENDERSON MICHAEL THOMAS

(Last) (First) (Middle)

C/O APOGEE THERAPEUTICS, INC.

221 CRESCENT ST., BLDG. 17, STE. 102B

(Street)

WALTHAM MASSACHUSETTS 02453

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Apogee Therapeutics, Inc. [ APGE ]

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

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/13/2026

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

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

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

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
Common Stock	05/13/2026		S(1)		18,659	D	$82.05(2)	1,117,328	D
Common Stock	05/13/2026		S(1)		1,341	D	$82.58(3)	1,115,987	D

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:

1. This transaction was executed pursuant to a Rule 10b5-1 trading plan adopted on August 13, 2025.

2. The price reported above is a weighted average price. The shares were sold in multiple transactions at prices ranging from $81.455 to $82.440, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission (the "SEC"), upon request, full information regarding the number of shares sold at each separate price within the range.

3. The price reported above is a weighted average price. The shares were sold in multiple transactions at prices ranging from $82.470 to $83.265, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range.

	/s/ Matthew Batters, as attorney-in-fact for Michael Henderson	05/15/2026
	** 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.
* Form 4: SEC 1474 (03-26)